JP2022039456A - Electric pump - Google Patents

Abstract

To provide an electric pump which can suppress the vibration of a pump mechanism.SOLUTION: A suction part 61 has a first suction-side recess 71 and a second suction-side recess 91. A discharge part has a first discharge-side recess and a second discharge-side recess. A bottom face of the first suction-side recess and a bottom face of the second suction-side recess have suction-side inclination faces inclined to faces intersecting with an axial direction, respectively. A bottom face of the first discharge-side recess and a bottom face of the second discharge-side recess have discharge-side inclination faces. The suction-side inclination face of the first suction-side recess and the suction-side inclination face of the second suction-side recess are at least partially overlapped on each other when viewed from an axial direction, and inclined in an orientation in which the faces approximate each other in the axial direction as progressing toward one side in a peripheral direction around a center axis. The discharge-side inclination face of the first discharge-side recess and the discharge-side inclination face of the second discharge-side recess are at least partially overlapped on each other when viewed from the axial direction, and inclined in an orientation in which the faces separate from each other as progressing toward one side in the peripheral direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electric pump.

A pump having a pump mechanism having an inner rotor and an inner rotor having outer teeth, and an outer rotor having inner teeth that surround the inner rotor and mesh with the outer teeth of the inner rotor is known. For example, Patent Document 1 describes a trochoidal gear pump as such a pump.

Jikkenhei 06-67876 Gazette

In a pump as described above, a pump accommodating portion for accommodating an inner rotor and an outer rotor, and a suction portion and a discharge portion connected to the pump accommodating portion are provided. When a fluid flows into the pump accommodating portion from the suction portion, there is a problem that the inner rotor and the outer rotor in the pump accommodating portion are tilted due to the pressure of the fluid.

One embodiment of the present invention comprises an inner rotor that is rotatable about an axially extending central axis and has external teeth, and an outer rotor that surrounds the inner rotor and has internal teeth that mesh with the external teeth. The pump housing includes a pump mechanism including, a pump accommodating portion accommodating the pump mechanism, and a suction portion and a discharge portion connected to the pump accommodating portion. The pump housing has a first end surface that faces the pump mechanism in the axial direction on one side in the axial direction of the pump mechanism, and the first end surface that faces the pump mechanism in the axial direction on the other side in the axial direction of the pump mechanism. It has a second end face that sandwiches the pump mechanism in the axial direction with the end face. The suction portion has a first suction-side recess recessed from the first end surface to one side in the axial direction, and a second suction-side recess recessed from the second end surface to the other side in the axial direction. The discharge portion has a first discharge side recess recessed from the first end surface to one side in the axial direction, and a second discharge side recess recessed from the second end surface to the other side in the axial direction. The bottom surface of the first suction-side recess and the bottom surface of the second suction-side recess each have a suction-side inclined surface that is inclined with respect to a surface that intersects the axial direction. The bottom surface of the first discharge-side recess and the bottom surface of the second discharge-side recess each have a discharge-side inclined surface that is inclined with respect to a surface that intersects the axial direction. At least a part of the suction-side inclined surface of the first suction-side recess and the suction-side inclined surface of the second suction-side recess overlap each other when viewed from the axial direction, and the circumference around the central axis. It is inclined toward each other in the axial direction toward one side of the direction. At least a part of the discharge-side inclined surface of the first discharge-side recess and the discharge-side inclined surface of the second discharge-side recess overlap each other when viewed from the axial direction, and the surface faces one side in the circumferential direction. It is tilted in the direction away from each other in the axial direction.

According to one aspect of the present invention, there is provided an electric pump capable of suppressing the runout of the pump mechanism.

FIG. 1 is a cross-sectional view of the electric pump of the present embodiment, and is a cross-sectional view taken along the line II of FIG. FIG. 2 is a perspective view including a partial cross section showing the structure of the pump mechanism and the suction side of the present embodiment. FIG. 3 is a perspective view showing the structure of the pump mechanism and the discharge side of the present embodiment, and is a perspective view including a cross section III-III in FIG. FIG. 4 is a cross-sectional view showing the structure of the pump mechanism, the suction portion, and the discharge portion of the present embodiment, the cross-sectional view of the pump housing side along the IV-IV line of FIG. 5, and the VI-VI line of FIG. Includes a cross-sectional view of the pump cover side along. FIG. 5 is a diagram showing a structure on the first suction side recess and the first discharge side recess on the pump housing side. FIG. 6 is a diagram showing the inner surface side of the pump cover. FIG. 7 is a diagram showing the positional relationship between the pump mechanism and the suction portion and the discharge portion on the pump housing side.

In each drawing referred to below, the XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system as appropriate.
In the XYZ coordinate system, the X-axis direction is a direction parallel to the axial direction of the central axis J shown in FIG. The central axis J is the central axis of the shaft 21 of the motor 220, which will be described later. The Y-axis direction is a direction orthogonal to the X-axis and parallel to the vertical direction in FIG. The Z-axis direction is a direction orthogonal to both the X-axis direction and the Y-axis direction, and is a direction parallel to the depth direction in FIG. In any of the X-axis direction, the Y-axis direction, and the Z-axis direction, the side facing the arrow shown in the figure is the + side, and the opposite side is the-side.

In the following description, unless otherwise specified, the direction parallel to the central axis J (X-axis direction) is simply referred to as "axial direction". The radial direction centered on the central axis J is simply referred to as "diameter direction". The circumferential direction around the central axis J, that is, the circumference of the central axis J is simply referred to as "circumferential direction". Of the circumferential direction, the side that advances clockwise when viewed from the + X side is referred to as "one side in the circumferential direction". Of the circumferential direction, the side traveling counterclockwise when viewed from the + X side is referred to as "the other side in the circumferential direction".

In the present embodiment, the downstream side in the direction in which the oil flows in the electric pump 200, which is the "one side in the circumferential direction", may be simply referred to as the "downstream side". Further, the "other side in the circumferential direction" and the upstream side in the direction in which the oil flows in the electric pump 200 may be simply referred to as "upstream side".

Further, the positive side (+ X side) in the X-axis direction may be referred to as "front side". Similarly, the negative side (-X side) in the X-axis direction may be referred to as "rear side". The rear side (-X side) corresponds to one side in the axial direction in the present invention. The front side (+ X side) corresponds to the other side in the axial direction in the present invention.

The electric pump 200 of the present embodiment is an electric oil pump that sends oil as a fluid. The electric pump 200 is used, for example, for supplying oil to equipment mounted on a vehicle or the like. As shown in FIGS. 1 and 2, the electric pump 200 includes a pump housing 210, a motor 220, and a pump mechanism 30.

The pump housing 210 includes a housing main body 211, a pump cover 212, and a motor cover 213. The housing main body 211 includes a motor accommodating portion 211a accommodating a motor 220, a pump accommodating portion 211b accommodating a pump mechanism 30, and a first through hole 211c connecting the inside of the motor accommodating portion 211a and the inside of the pump accommodating portion 211b. , Have.

The motor accommodating portion 211a is provided on the rear side (−X side) portion of the housing main body 211. The motor accommodating portion 211a has a cylindrical shape that opens to the rear side and extends in the axial direction. The opening on the rear side of the motor accommodating portion 211a is closed from the rear side by the motor cover 213. The motor 220 housed in the motor accommodating portion 211a includes a rotor 22 having a shaft 21, a stator 23 located radially outside the rotor 22, a bus bar assembly 224, a bus bar cover 225, a first bearing 27, and a second bearing 27. It has a bearing 28 and. The first bearing 27 and the second bearing 28 are rolling bearings in this embodiment. Either or both of the first bearing 27 and the second bearing 28 may be plain bearings. The front end of the shaft 21 is connected to the pump mechanism 30.

As shown in FIG. 1, the bus bar assembly 224 has a plurality of bus bars 224a and a resin bus bar holder 224b for holding the plurality of bus bars 224a. The bus bar assembly 224 is annular when viewed from the axial direction. The plurality of bus bars 224a are partially embedded and held in the bus bar holder 224b.

The bus bar assembly 224 is located on the rear side of the stator 23. The bus bar assembly 224 is inserted into the motor accommodating portion 211a from the rear side.
One end of the bus bar 224a is connected to a coil wire 23d extending from the coil 23c of the stator 23 to the rear side.

The bus bar cover 225 is located on the rear side of the bus bar assembly 224. The bus bar cover 225 is inserted into the motor accommodating portion 211a from the rear side. Although not shown, the bus bar cover 225 is annular when viewed from the axial direction. The bus bar cover 225 covers the bus bar assembly 224 from the rear side. The motor cover 213 is covered from the rear side of the bus bar cover 225.

The motor cover 213 is a disk-shaped member that covers the bus bar cover 225 from the rear side. The motor cover 213 has a cylindrical portion 213a extending along the central axis J, and an annular cover body 213b extending radially outward from the outer peripheral surface of the cylindrical portion 213a. Although not shown, the cylindrical portion 213a opens on both sides of the motor cover 213 in the axial direction. As shown in FIG. 2, the opening on the front side of the cylindrical portion 213a is a bearing holding portion 213c that holds the first bearing 27. As shown in FIG. 3, a breather 60 is attached to the opening on the rear side of the cylindrical portion 213a. Although not shown, the breather 60 has a built-in filter. The filter of the breather 60 is, for example, a gas-liquid separation filter that allows gas to pass through and blocks liquid.

The cover body 213b extends radially to the outside of the bus bar cover 225. The cover body 213b is screwed to the housing body 211 at a portion located radially outside the bus bar cover 225.

As shown in FIG. 2, the second bearing 28 is inserted into the first through hole 211c from the rear side. Inside the first through hole 211c, an oil seal 15, a fixing ring 16, a wave washer 17, and a second bearing 28 are arranged in order from the front side.

The shaft 21 is passed through the inner holes of the second bearing 28, the wave washer 17, the fixing ring 16, and the oil seal 15. The pump mechanism 30 is connected to the front end of the shaft 21.

The pump accommodating portion 211b is located on the front side (+ X side) of the motor accommodating portion 211a. The pump accommodating portion 211b is composed of a recess that opens on the front side. The pump accommodating portion 211b is, for example, a circular recess when viewed from the front side. The opening on the front side of the pump accommodating portion 211b is closed from the front side by the pump cover 212. The pump mechanism 30 housed in the pump housing portion 211b has an inner rotor 31 connected to the front end of the shaft 21 and an outer rotor 32 located radially outside the inner rotor 31.

The pump mechanism 30 of the present embodiment is, for example, a trochoidal pump. The inner rotor 31 and the outer rotor 32 mesh with each other. The inner rotor 31 having outer teeth and the outer rotor 32 having inner teeth 32a that mesh with the outer teeth 31a of the inner rotor 31 are pump gears. The inner rotor 31 and the outer rotor 32 each have a trochoidal tooth profile. The shaft 21 of the motor 220 is connected to the inner rotor 31. The inner rotor 31 is rotated by rotating the shaft 21 around the central axis J. As the inner rotor 31 rotates, the outer rotor 32 that meshes with the inner rotor 31 also rotates. In this way, the motor 220 rotates the inner rotor 31 to drive the pump mechanism 30. The rotation axis of the outer rotor 32 is an axis eccentric in the radial direction with respect to the central axis J.

The pump cover 212 is fixed to the front side of the housing body 211. The pump cover 212 extends radially outward from the pump accommodating portion 211b. The pump cover 212 is fastened to the housing-side connecting end surface 211d facing the front side of the housing main body 211 at a position radially outside the pump accommodating portion 211b by using a plurality of screws 215 shown in FIG. An annular seal member 214 that surrounds the opening of the pump accommodating portion 211b from the outside in the radial direction is arranged on the housing side connection end surface 211d. The sealing member 214 seals between the housing body 211 and the pump cover 212.

As shown in FIG. 4, the pump housing 210 includes a first end surface 210a, a second end surface 210b, a suction portion 61 and a discharge portion 62 connected to the pump accommodating portion 211b, a suction side flow path 81, and a discharge side flow path 82. And have. The first end surface 210a is provided on the housing body 211. The first end surface 210a is a surface located on the rear side of the inner surface of the pump accommodating portion 211b. The first end surface 210a faces the front side. The first end surface 210a faces the pump mechanism 30 in the axial direction on the rear side of the pump mechanism 30. The first end surface 210a is, for example, a flat surface orthogonal to the axial direction.

The second end surface 210b is provided on the pump cover 212. The second end surface 210b is a portion of the rear surface of the pump cover 212 facing the pump mechanism 30. The second end surface 210b faces the rear side. The second end surface 210b faces the pump mechanism 30 in the axial direction on the front side of the pump mechanism 30. The second end surface 210b sandwiches the pump mechanism 30 in the axial direction with the first end surface 210a. The second end surface 210b closes the opening on the front side of the pump accommodating portion 211b. The second end surface 210b is, for example, a flat surface orthogonal to the axial direction.

As shown in FIG. 2, the suction unit 61 is connected to the suction port 51 provided on the side surface of the pump housing 210 via the suction side flow path 81. The suction port 51 is located, for example, on the motor 220 side of the pump accommodating portion 211b. The oil that has flowed into the suction side flow path 81 from the suction port 51 flows into the suction unit 61. As shown in FIGS. 2 and 4, the suction portion 61 is located on the first suction side recess 71 located on the housing body 211 side with respect to the pump accommodating portion 211b and on the pump cover 212 side with respect to the pump accommodating portion 211b. It has a second suction-side recess 91 and a recess 91. The shape of the first suction-side recess 71 seen from the axial direction and the shape of the second suction-side recess 91 seen from the axial direction are, for example, the same shape as each other. At least a part of the first suction side recess 71 and the second suction side recess 91 overlap each other when viewed from the axial direction. The first suction-side recess 71 and the second suction-side recess 91, for example, overlap each other as a whole when viewed from the axial direction.

As shown in FIG. 3, the discharge unit 62 is connected to the discharge port 52 provided on the side surface of the pump housing 210 via the discharge side flow path 82. The discharge port 52 is located, for example, on the motor 220 side of the pump accommodating portion 211b. The oil discharged from the pump mechanism 30 flows into the discharge unit 62. As shown in FIGS. 3 and 4, the discharge portion 62 is located on the first discharge side recess 72 located on the housing body 211 side with respect to the pump accommodating portion 211b and on the pump cover 212 side with respect to the pump accommodating portion 211b. It has a second discharge side recess 92 and a second discharge side recess 92. The shape of the first discharge-side recess 72 seen from the axial direction and the shape of the second discharge-side recess 92 seen from the axial direction are, for example, the same shape as each other. At least a part of the first discharge side recess 72 and the second discharge side recess 92 overlap each other when viewed from the axial direction. The first discharge-side recess 72 and the second discharge-side recess 92, for example, are entirely overlapped with each other when viewed from the axial direction.

As shown in FIG. 4, the first suction-side recess 71 and the first discharge-side recess 72 are recessed from the first end surface 210a to the rear side. The first suction-side recess 71 and the first discharge-side recess 72 are arranged at the same position in the axial direction, for example. The depth T1 in the axial direction of the first suction-side recess 71 and the depth T2 in the axial direction of the first discharge-side recess 72 are, for example, the same as each other. The depth T1 and the depth T2 may be different from each other.

As shown in FIG. 5, the first suction-side recess 71 and the first discharge-side recess 72 are, for example, grooves extending in the circumferential direction. In the present embodiment, when viewed from the axial direction, the first suction-side recess 71 and the first discharge-side recess 72 extend in an arc shape along the circumferential direction around the central axis J.

As shown in FIG. 7, the radial outer edge portion of the first suction side recess 71 and the radial outer edge portion of the first discharge side recess 72 are along the outer peripheral circle of the outer rotor 32 of the pump mechanism 30 when viewed from the axial direction. It extends in an arc shape in the vertical direction, that is, in the circumferential direction around the rotation axis of the outer rotor 32. The radial inner edge portion of the first suction side recess 71 and the radial inner edge portion of the first discharge side recess 72 extend in an arc shape in the circumferential direction around the central axis J when viewed from the axial direction.

When viewed from the axial direction, the side surface 71a of the first suction side recess 71 facing inward in the radial direction and the side surface 72a of the first discharge side recess 72 facing inward in the radial direction are the radial direction of the outer rotor 32 of the pump mechanism 30. Of the inner peripheral surface 32b facing inward, it overlaps with a plurality of portions 32c having the maximum diameter in the axial direction.

As shown by a thick arrow in FIG. 5, oil flows from the other side in the circumferential direction to one side in the circumferential direction in the first suction side recess 71 and the first discharge side recess 72. That is, in the first suction side recess 71 and the first discharge side recess 72, the other side in the circumferential direction, that is, the side opposite to the side facing the thick arrow in FIG. 5 is the upstream side, and one side in the circumferential direction, that is, FIG. The side facing the thick arrow is the downstream side.

The width of the first suction-side recess 71 in the present embodiment gradually increases in the radial direction from the upstream end 71h to the downstream end 71j along the circumferential direction around the central axis J. The upstream side end portion 71h is the end portion on the other side in the circumferential direction of the first suction side recess 71. The downstream end portion 71j is one end portion in the circumferential direction of the first suction side recess 71. That is, the radial width of the first suction-side recess 71 increases from the other side in the circumferential direction toward one side in the circumferential direction.

On the other hand, the width of the first discharge-side recess 72 gradually narrows in the radial direction from the upstream end 72h to the downstream end 72j along the circumferential direction around the central axis J. The upstream side end portion 72h is the end portion on the other side in the circumferential direction of the first discharge side recess 72. The downstream end portion 72j is one end portion in the circumferential direction of the first discharge side recess 72. That is, the radial width of the first discharge side recess 72 decreases from the other side in the circumferential direction toward one side in the circumferential direction.

As shown in FIG. 4, the second suction-side recess 91 and the second discharge-side recess 92 are recessed from the second end surface 210b to the front side. The depth T3 of the second suction-side recess 91 in the axial direction and the depth T4 of the second discharge-side recess 92 in the axial direction are, for example, the same as each other. The depth T3 and the depth T4 may be different from each other. The depths T3 and T4 of the second suction-side recess 91 and the second discharge-side recess 92 are smaller than the depths T1 and T2 of the first suction-side recess 71 and the first discharge-side recess 72. Not limited to this, even if the depths T3 and T4 of the second suction side recess 91 and the second discharge side recess 92 are larger than the depths T1 and T2 of the first suction side recess 71 and the first discharge side recess 72. good.

As shown in FIG. 6, the second suction side recess 91 and the second discharge side recess 92 are, for example, grooves extending in the circumferential direction. In the present embodiment, when viewed from the axial direction, the second suction-side recess 91 and the second discharge-side recess 92 extend in an arc shape along the circumferential direction around the central axis J.

The radial outer edge portion of the second suction side recess 91 and the radial outer edge portion of the second discharge side recess 92 extend in an arc shape in the circumferential direction around the rotation axis of the outer rotor 32 when viewed from the axial direction. The radial inner edge portion of the second suction side recess 91 and the radial inner edge portion of the second discharge side recess 92 extend in an arc shape in the circumferential direction around the central axis J when viewed from the axial direction. Although not shown, the side surface of the second suction side recess 91 facing inward in the radial direction and the side surface of the second discharge side recess 92 facing inward in the radial direction face the radial inside of the outer rotor 32 of the pump mechanism 30. Of the inner peripheral surface 32b, it overlaps with a plurality of portions 32c having the maximum diameter in the axial direction.

As shown by a thick arrow in FIG. 6, oil flows from the other side in the circumferential direction to one side in the circumferential direction in the second suction side recess 91 and the second discharge side recess 92. That is, in the second suction side recess 91 and the second discharge side recess 92, the other side in the circumferential direction, that is, the side opposite to the side facing the thick arrow in FIG. 6 is the upstream side, and one side in the circumferential direction, that is, FIG. The side facing the thick arrow is the downstream side.

As shown in FIG. 6, the second suction-side recess 91 in the present embodiment has a radial width from the upstream end 91h to the downstream end 91j along the circumferential direction around the central axis J. Gradually spreads. The upstream side end portion 91h is the end portion on the other side in the circumferential direction of the second suction side recess 91. The downstream end portion 91j is one end of the second suction side recess 91 in the circumferential direction. That is, the radial width of the second suction-side recess 91 increases from the other side in the circumferential direction toward one side in the circumferential direction.

On the other hand, the width of the second discharge-side recess 92 gradually narrows in the radial direction from the upstream end portion 92h to the downstream end portion 92j along the circumferential direction around the central axis J. The upstream side end portion 92h is the end portion on the other side in the circumferential direction of the second discharge side recess 92. The downstream end portion 92j is one end of the second discharge side recess 92 in the circumferential direction. That is, the radial width of the second discharge side recess 92 decreases from the other side in the circumferential direction toward one side in the circumferential direction.

As shown in FIG. 4, the suction side flow path 81 is connected to the first suction side recess 71. The suction-side flow path 81 opens on the side surface 71a facing the radial inward side of the first suction-side recess 71. A discharge side flow path 82 is connected to the first discharge side recess 72. The discharge side flow path 82 opens on the side surface 72a of the first discharge side recess 72 facing inward in the radial direction.

The bottom surface 71f of the first suction-side recess 71 has a suction-side flat surface 71c and a suction-side inclined surface 71b. The bottom surface 71f is a surface of the inner side surface of the first suction side recess 71 that is located on the rear side and faces the front side. The bottom surface 72f of the first discharge-side recess 72 has a discharge-side flat surface 72c and a discharge-side inclined surface 72b. The bottom surface 72f is a surface of the inner side surface of the first discharge side recess 72 that is located on the rear side and faces the front side.

The suction-side flat surface 71c and the discharge-side flat surface 72c are surfaces that intersect the axial direction. The suction-side flat surface 71c and the discharge-side flat surface 72c are, for example, planes orthogonal to the axial direction. The suction-side flat surface 71c and the discharge-side flat surface 72c are, for example, parallel to the first end surface 210a. The suction-side flat surface 71c of the first suction-side recess 71 is located closer to the suction-side flow path 81 than the suction-side inclined surface 71b in the circumferential direction, and is on the other side (upstream side) of the suction-side inclined surface 71b in the circumferential direction. Connect to the end. The discharge-side flat surface 72c of the first discharge-side recess 72 is located closer to the discharge-side flow path 82 than the discharge-side inclined surface 72b in the circumferential direction, and is on one side (downstream side) of the discharge-side inclined surface 72b in the circumferential direction. Connect to the end.

The suction-side inclined surface 71b and the discharge-side inclined surface 72b are surfaces that are inclined with respect to the suction-side flat surface 71c and the discharge-side flat surface 72c. The suction-side inclined surface 71b is located on the front side from the suction-side flat surface 71c toward one side (downstream side) in the circumferential direction. The discharge side inclined surface 72b is located on the front side from the discharge side flat surface 72c toward the other side (upstream side) in the circumferential direction. The inclination angle θ1 of the suction-side inclined surface 71b with respect to the suction-side flat surface 71c and the inclination angle θ2 of the discharge-side inclined surface 72b with respect to the discharge-side flat surface 72c are, for example, the same. The inclination angles θ1 and θ2 are preferably in the range of, for example, 15 ° to 35 °. The tilt angle θ1 and the tilt angle θ2 may be different from each other.

The first suction-side recess 71 has a surface 71d extending axially from the downstream end portion 71j on one side in the circumferential direction of the suction-side inclined surface 71b toward the pump mechanism 30 on the front side. The surface 71d is, for example, a surface orthogonal to the circumferential direction. The first discharge-side recess 72 has a surface 72d extending axially from the upstream end 72h on the other side in the circumferential direction of the discharge-side inclined surface 72b toward the pump mechanism 30 on the front side. The surface 72d is, for example, a surface orthogonal to the circumferential direction.

The bottom surface 91f of the second suction-side recess 91 has a suction-side flat surface 91c and a suction-side inclined surface 91b. The bottom surface 91f is a surface of the inner side surface of the second suction side recess 91 that is located on the front side and faces the rear side. The bottom surface 92f of the second discharge-side recess 92 has a discharge-side flat surface 92c and a discharge-side inclined surface 92b. The bottom surface 92f is a surface of the inner side surface of the second discharge side recess 92 that is located on the front side and faces the rear side.

The suction-side flat surface 91c and the discharge-side flat surface 92c are surfaces that intersect the axial direction. The suction-side flat surface 91c and the discharge-side flat surface 92c are, for example, planes orthogonal to the axial direction. The suction-side flat surface 91c and the discharge-side flat surface 92c are, for example, parallel to the second end surface 210b. The suction-side flat surface 91c of the second suction-side recess 91 is located closer to the suction-side flow path 81 than the suction-side inclined surface 91b in the circumferential direction, and is the other (upstream) end of the suction-side inclined surface 91b in the circumferential direction. Connect to the club. The discharge-side flat surface 92c of the second discharge-side recess 92 is located closer to the discharge-side flow path 82 than the discharge-side inclined surface 92b in the circumferential direction, and is one (downstream) end of the discharge-side inclined surface 92b in the circumferential direction. Connect to the club.

The suction-side inclined surface 91b and the discharge-side inclined surface 92b are surfaces that are inclined with respect to the suction-side flat surface 91c and the discharge-side flat surface 92c. The suction-side inclined surface 91b is located on the rear side from the suction-side flat surface 91c toward one side (downstream side) in the circumferential direction. The discharge-side inclined surface 92b is located on the rear side from the discharge-side flat surface 92c toward the other side (upstream side) in the circumferential direction.

The inclination angle θ3 of the suction-side inclined surface 91b with respect to the suction-side flat surface 91c and the inclination angle θ4 of the discharge-side inclined surface 92b with respect to the discharge-side flat surface 92c are, for example, the same. The inclination angles θ3 and θ4 are preferably in the range of, for example, 0 ° to 15 °. In the present embodiment, the size of the tilt angles θ3 and θ4 is smaller than the size of the tilt angles θ1 and θ2. The tilt angle θ3 and the tilt angle θ4 may be different from each other. The magnitudes of the tilt angles θ3 and θ4 may be the same as the magnitudes of the tilt angles θ1 and θ2, or may be larger than the magnitudes of the tilt angles θ1 and θ2.

The second suction-side recess 91 has a surface 91d extending axially from the downstream end portion 91j on one side in the circumferential direction of the suction-side inclined surface 91b toward the pump mechanism 30 on the rear side. The surface 91d is, for example, a surface orthogonal to the circumferential direction. The second discharge-side recess 92 has a surface 92d extending axially from the upstream end portion 92h on the other side in the circumferential direction of the discharge-side inclined surface 92b toward the pump mechanism 30 on the rear side. The surface 92d is, for example, a surface orthogonal to the circumferential direction.

At least a part of the bottom surface 71f of the first suction side recess 71 and the bottom surface 91f of the second suction side recess 91 in the suction portion 61 overlap each other when viewed from the axial direction. At least a part of the suction-side inclined surface 71b of the first suction-side recess 71 and the suction-side inclined surface 91b of the second suction-side recess 91 overlap each other when viewed from the axial direction. In the present embodiment, at least a part of the suction-side flat surface 71c of the first suction-side recess 71 and the suction-side flat surface 91c of the second suction-side recess 91 overlap each other when viewed from the axial direction. It is preferable that the bottom surface 71f of the first suction-side recess 71 and the bottom surface 91f of the second suction-side recess 91 overlap each other by, for example, 80% to 90% or more in the axial direction.

The bottom surface 71f of the first suction side recess 71 and the bottom surface 91f of the second suction side recess 91 have, for example, the same area when viewed from the axial direction. The bottom surface 71f of the first suction side recess 71 and the bottom surface 91f of the second suction side recess 91 overlap each other, for example, when viewed from the axial direction. The suction-side inclined surface 71b and the suction-side inclined surface 91b have, for example, the same area seen in the axial direction. The suction-side inclined surface 71b and the suction-side inclined surface 91b, for example, overlap each other as a whole when viewed from the axial direction. The suction-side flat surface 71c and the suction-side flat surface 91c have, for example, the same area when viewed from the axial direction. The suction-side flat surface 71c and the suction-side flat surface 91c, for example, overlap each other as a whole when viewed from the axial direction.

In the present embodiment, the boundary portion B1 between the suction-side flat surface 71c and the suction-side inclined surface 71b in the first suction-side recess 71 is the suction-side flat surface 91c in the second suction-side recess 91 and suction. It overlaps with the boundary portion B2 with the side inclined surface 91b.

At least a part of the bottom surface 72f of the first discharge side recess 72 and the bottom surface 92f of the second discharge side recess 92 in the discharge portion 62 overlap each other when viewed from the axial direction. At least a part of the discharge-side inclined surface 72b of the first discharge-side recess 72 and the discharge-side inclined surface 92b of the second discharge-side recess 92 overlap each other when viewed from the axial direction. In the present embodiment, at least a part of the discharge-side flat surface 72c of the first discharge-side recess 72 and the discharge-side flat surface 92c of the second discharge-side recess 92 overlap each other when viewed from the axial direction. It is preferable that the bottom surface 72f of the first discharge side recess 72 and the bottom surface 92f of the second discharge side recess 92 overlap, for example, 80% to 90% or more of the area of each other when viewed from the axial direction.

The bottom surface 72f of the first discharge side recess 72 and the bottom surface 92f of the second discharge side recess 92 have, for example, the same area when viewed from the axial direction. The bottom surface 72f of the first discharge side recess 72 and the bottom surface 92f of the second discharge side recess 92 overlap each other, for example, when viewed from the axial direction. The discharge-side inclined surface 72b and the discharge-side inclined surface 92b have, for example, the same area seen in the axial direction. The discharge-side inclined surface 72b and the discharge-side inclined surface 92b, for example, are entirely overlapped with each other when viewed from the axial direction. The discharge-side flat surface 72c and the discharge-side flat surface 92c have, for example, the same area when viewed from the axial direction. The discharge-side flat surface 72c and the discharge-side flat surface 92c overlap each other, for example, when viewed from the axial direction.

In the present embodiment, the boundary portion B3 between the discharge-side flat surface 72c and the discharge-side inclined surface 72b in the first discharge-side recess 72 is discharged from the discharge-side flat surface 92c in the second discharge-side recess 92 when viewed from the axial direction. It overlaps with the boundary portion B4 with the side inclined surface 92b.

In addition, in this specification, "a certain boundary part overlaps with another boundary part when viewed from an axial direction" is one of a part of a certain boundary part and another boundary part when viewed from the axial direction. It suffices if the parts overlap at least.

As shown in FIG. 5, the first discharge-side recess 72 has a semicircular notch 72k at the upstream end 72h. As shown in FIG. 6, the second discharge side recess 92 has a semicircular notch 92k on the upstream side end portion 92h side.

The suction side flow path 81 is connected to a portion of the first suction side recess 71 where the bottom surface 71f is the suction side flat surface 71c. The connection position where the suction side flow path 81 is connected to the first suction side recess 71 is separated from the upstream end portion 71h on one side in the circumferential direction.

As shown in FIG. 2, the suction-side flow path 81 extends radially outward from the connection position with the first suction-side recess 71, and extends from the radial outer end of the flow path 81a to the rear side. It has a flow path 81b and a flow path 81c extending radially outward from the rear end of the flow path 81b. The radial outer end of the flow path 81c is connected to a suction port 51 that opens on the outer peripheral surface of the pump housing 210. That is, the suction side flow path 81 is a flow path that connects the suction port 51 that opens on the radial outer surface of the pump housing 210 and the first suction side recess 71.

A cap 85 is fitted from the outer peripheral surface of the pump housing 210 to the intersection of the flow path 81a and the flow path 81b. The cap 86 is fitted into the front end of the flow path 81b from the front end of the pump housing 210. The caps 85 and 86 close the openings of the drill holes constituting the flow paths 81a and 81b. The flow path extending from the intersection of the flow path 81a and the flow path 81b to the cap 86 is a hole formed in the process of forming the flow path 81b by the mold, and is a suction side flow path from the functional aspect as the flow path. It is not an essential part for 81.

As shown in FIG. 5, the discharge side flow path 82 is connected to a portion of the first discharge side recess 72 where the bottom surface 72f is the discharge side flat surface 72c. The connection position where the discharge side flow path 82 is connected to the first discharge side recess 72 is separated from the downstream end portion 72j to the other side in the circumferential direction.

As shown in FIG. 3, the discharge side flow path 82 has a flow path 82a extending radially outward from the connection position with the first discharge side recess 72. The radial outer end of the flow path 82a is connected to a discharge port 52 that opens on the outer peripheral surface of the pump housing 210. The discharge side flow path 82 has a flow path 82b that branches from the flow path 82a and extends to the rear side. The rear end of the flow path 82b reaches the rear end of the pump housing 210.

A relief valve 95 is arranged in the flow path 82b. The relief valve 95 has a valve body 95a that can move along the axial direction, a coil spring 95b that pushes the valve body 95a toward the front side, and a fixing portion 95c that supports the rear end portion of the coil spring 95b. The fixing portion 95c has a male screw shape and is fastened to the rear end portion of the flow path 82b. The fixing portion 95c closes the opening at the rear end of the flow path 82b.

As shown in FIG. 3, the discharge side flow path 82 has a flow path 82c extending from the flow path 82b to the lower side in the drawing. The flow path 82c is branched from a region in which the valve body 95a in the flow path 82b advances and retreats in the axial direction. The lower end of the flow path 82c in the drawing is connected to the suction side flow path 81 shown in FIG. In the case of the present embodiment, the flow path 82c is connected to a position on the rear side of the position where the flow path 81c is connected to the flow path 81b.

The relief valve 95 operates by the pressure of the discharge side flow path 82. When the valve body 95a retracts to the rear side by a predetermined length or more due to the oil pressure, the flow path 82b and the flow path 82c are connected, and a part of the oil in the discharge side flow path 82 is returned to the suction side flow path 81. As a result, the discharge pressure of the electric pump 200 can be maintained below the limit value. Further, by installing the relief valve 95, it is possible to suppress damage to the piping and equipment due to abnormal pressure.

When the pump mechanism 30 is driven by the motor 220, oil is sucked into the suction side flow path 81 from the suction port 51. As shown by a thick arrow in FIG. 2, the oil sucked into the suction side flow path 81 flows through the flow path 81c, the flow path 81b, and the flow path 81a in this order, and flows into the first suction side recess 71. .. As shown by the arrow F in FIG. 4, the oil sucked from the suction side flow path 81 into the first suction side recess 71 by the pumping action flows into the first suction side recess 71 to the pump mechanism 30. Be sucked. More specifically, the oil in the first suction side recess 71 is sucked between the outer teeth 31a of the inner rotor 31 and the inner teeth 32a of the outer rotor 32. The oil sucked by the pump mechanism 30 moves to one side in the circumferential direction in the pump accommodating portion 211b as the inner rotor 31 and the outer rotor 32 rotate. A part of the oil sucked into the pump mechanism 30 also flows into the second suction side recess 91. The oil in the second suction side recess 91 is sucked again between the outer teeth 31a of the inner rotor 31 and the inner teeth 32a of the outer rotor 32 while flowing to one side in the circumferential direction, for example.

In the electric pump 200 having such a configuration, the oil moved to one side in the circumferential direction in the pump accommodating portion 211b by the pump mechanism 30 flows into the first discharge side recess 72 and the second discharge side recess 92. The oil that has flowed into the first discharge-side recess 72 flows through the first discharge-side recess 72 to one side in the circumferential direction and is discharged to the discharge-side flow path 82. The oil flowing into the second discharge side recess 92 is sucked again between the outer teeth 31a of the inner rotor 31 and the inner teeth 32a of the outer rotor 32 while flowing to one side in the circumferential direction, for example, in FIG. As shown by the arrow F of, the oil is discharged to the discharge side flow path 82 through the first discharge side recess 72. As shown by a thick arrow in FIG. 3, the oil discharged to the discharge side flow path 82 flows through the flow path 82a and is discharged from the discharge port 52 to the outside of the electric pump 200.

In the electric pump 200 of the present embodiment, the bottom surface 71f of the first suction side recess 71 and the bottom surface 91f of the second suction side recess 91 have suction side inclined surfaces 71b and 91b that are inclined with respect to the surface intersecting the axial direction, respectively. Have. At least a part of the suction-side inclined surface 71b of the first suction-side recess 71 and the suction-side inclined surface 91b of the second suction-side recess 91 overlap each other when viewed from the axial direction, and the circumference around the central axis J It is inclined toward each other in the axial direction toward one side of the direction. Therefore, the oil in the first suction-side recess 71 and the oil in the second suction-side recess 91 are circumferentially along the suction-side inclined surfaces 71b and 91b as the pump mechanism 30 rotates to one side in the circumferential direction. While flowing to one side, it is guided in the axial direction toward the inside of the pump accommodating portion 211b.

As a result, while maintaining a balance between the front-side force received by the pump mechanism 30 from the oil in the first suction-side recess 71 and the rear-side force received by the pump mechanism 30 from the oil in the second suction-side recess 91. Oil can be sucked into the pump mechanism 30 from the inside of the first suction side recess 71 and the inside of the second suction side recess 91. Therefore, the pump mechanism 30 can be rotated while the pump mechanism 30 is suitably pressed from both sides in the axial direction by the pressure of oil. Therefore, it is possible to suppress the inner rotor 31 and the outer rotor 32 from tilting in the pump accommodating portion 211b, and it is possible to suppress the vibration of the inner rotor 31 and the outer rotor 32. As a result, the inner rotor 31 and the outer rotor 32 can be rotated stably. Therefore, it is possible to suppress a decrease in the suction amount of the oil discharged from the pump mechanism 30 and a pulsation of the suction pressure. Further, the friction between the inner rotor 31 and the outer rotor 32 and the inner surface of the pump accommodating portion 211b can be reduced.

On the other hand, the discharge side inclined surfaces 72b and 92b facing each other in the axial direction on the discharge portion 62 side are inclined in a direction away from each other in the axial direction as they go to one side (downstream side) in the circumferential direction. Therefore, the oil discharged from the pump mechanism 30 is efficiently guided into the first discharge side recess 72 and the second discharge side recess 92 along the discharge side inclined surfaces 72b and 92b. As a result, the force toward the rear side of the oil discharged from the pump mechanism 30 into the first discharge side recess 72 and the direction toward the front side of the oil discharged from the pump mechanism 30 into the second discharge side recess 92. Oil can be discharged from the pump mechanism 30 to the first discharge side recess 72 and the second discharge side recess 92 while maintaining a balance with the force. Therefore, it is possible to suppress the inner rotor 31 and the outer rotor 32 from tilting in the pump accommodating portion 211b, and it is possible to suppress the vibration of the inner rotor 31 and the outer rotor 32. As a result, the inner rotor 31 and the outer rotor 32 can be rotated stably. Therefore, it is possible to suppress a decrease in the discharge amount of the oil discharged from the pump mechanism 30 and a pulsation of the discharge pressure.

In this way, the balance between the suction amount and the suction pressure of the oil with respect to the pump mechanism 30 and the discharge amount and the discharge pressure becomes equal on the suction side and the discharge side, so that the inner rotor 31 and the outer rotor 32 and the pump are accommodated. Friction with the inner surface of the portion 211b can be reduced, and rotational loss of the inner rotor 31 can be suppressed. Further, it is possible to reduce the wear between the inner rotor 31 and the outer rotor 32 and the inner surface of the pump cover 212 and the inner surface of the pump accommodating portion 211b. Since the wear can be reduced, heat generation and wear debris can be suppressed, and adverse effects on the electric pump 200 can be suppressed.

Further, in the present embodiment, on the suction portion 61 side, the boundary portion B1 between the suction side flat surface 71c and the suction side inclined surface 71b in the first suction 2019P-0374JP inlet side recess 71 is the second when viewed from the axial direction. It overlaps with the boundary portion B2 between the suction-side flat surface 91c and the suction-side inclined surface 91b in the suction-side recess 91. As a result, substantially the entire suction-side inclined surface 71b and the suction-side inclined surface 91b that face each other in the axial direction overlap each other, so that the oil in one of the first suction-side recesses 71 flows along the suction-side inclined surface 71b in the circumferential direction. At the position, the oil in the other second suction side recess 91 also flows along the suction side inclined surface 91b.
On the other hand, on the discharge portion 62 side, the boundary portion B3 between the discharge side flat surface 72c in the first discharge side recess 72 and the discharge side inclined surface 72b is the discharge side flat surface in the second discharge side recess 92 when viewed from the axial direction. It overlaps with the boundary portion B4 between the 92c and the discharge side inclined surface 92b. As a result, substantially the entire discharge-side inclined surface 72b and the discharge-side inclined surface 92b facing each other in the axial direction overlap each other, so that the oil in one of the first discharge-side recesses 72 flows along the discharge-side inclined surface 72b in the circumferential direction. At the position, the oil in the other second discharge side recess 92 also flows along the discharge side inclined surface 92b.
Therefore, it is easier to maintain the balance of the pressure received from the oil by the pump mechanism 30 from both sides in the axial direction on both the suction side and the discharge side. Therefore, the rotation of the inner rotor 31 becomes more stable during suction and discharge.

Further, in the present embodiment, the suction-side flat surface 71c of the first suction-side recess 71 and the discharge-side flat surface 72c of the first discharge-side recess 72 on the pump housing 210 side are arranged at the same positions in the axial direction. ing. As a result, the positions of the suction side flow path 81 and the discharge side flow path 82 connected to the first suction side recess 71 and the first discharge side recess 72 can be easily aligned in the axial direction. As a result, the oil can be easily flowed from the suction side flow path 81 to the discharge side flow path 82 as compared with the positions where the suction side flat surface 71c and the discharge side flat surface 72c are different in the axial direction. Therefore, the pump mechanism 30 rotates more stably.

In the present embodiment, the first suction-side recess 71 and the second suction-side recess 91 are surfaces 71d extending axially toward the pump mechanism 30 from one end in the circumferential direction of the suction-side inclined surfaces 71b and 91b. , 91d, respectively. Further, the first discharge-side recess 72 and the second discharge-side recess 92 are surfaces extending axially from the upstream end of the discharge-side inclined surfaces 72b and 92b on the other side in the circumferential direction toward the pump mechanism 30. It has 72d and 92d, respectively. As described above, the surfaces 71d and 91d rising from the bottom surfaces 71f and 91f toward the pump mechanism 30 facilitate the suction of oil to the pump mechanism 30, and the surfaces 72d extending from the pump mechanism 30 side toward the bottom surfaces 72f and 92f. Oil is easily discharged from the pump mechanism 30 by 92d. Further, the axial depths of the recesses 71, 72, 91, 92 can be increased by the surfaces 71d, 91d, 72d, 92d along the axial direction, and the oil sucked or discharged to the pump mechanism 30 can be increased. Recoil in the flow is suppressed. As a result, the pulsation of the oil is reduced and the oil can flow smoothly.

Further, when viewed from the axial direction, the first suction-side recess 71, the first discharge-side recess 72, the second suction-side recess 91, and the second discharge-side recess 92 have an arc shape along the circumferential direction around the central axis. Extends to. As a result, the oil flowing in from the suction side flow path 81 is guided to the pump mechanism 30 while flowing along the arcs of the first suction side recess 71 and the second suction side recess 91, and is efficiently sucked. Further, the oil discharged from the pump mechanism 30 is efficiently discharged to the discharge side flow path 82 while flowing along the arcs of the first discharge side recess 72 and the second discharge side recess 92.

As described above, in the electric pump 200 of the present embodiment, by suppressing the runout of the pump mechanism 30, not only the friction can be reduced, but also the pulsation of the pump can be reduced, and the efficiency can be expected to be improved.

To the extent that it does not deviate from the gist of the present invention, each configuration (component) described in the above-described embodiments, modifications, and notes may be combined, and addition, omission, replacement, or other modification of the configuration may be performed. It is possible.

22 ... Rotor, 30 ... Pump mechanism, 31 ... Inner rotor, 31a ... External teeth, 32 ... Outer rotor, 32a ... Internal teeth, 61 ... Suction part, 62 ... Discharge part, 71 ... First suction side recess, 71b ... Suction Side inclined surface, 71c ... Suction side flat surface, 71d, 72d, 91d, 92d ... (extending in the axial direction) surface, 72b ... Discharge side inclined surface, 72c ... Discharge side flat surface, 71f, 72f, 91f, 92f ... Bottom surface 72 ... 1st discharge side recess, 91 ... 2nd suction side recess, 91b ... suction side inclined surface, 91c ... suction side flat surface, 92 ... second discharge side recess, 92b ... discharge side inclined surface, 92c ... discharge side Flat surface, 200 ... Electric pump, 210 ... Pump housing, 210a ... First end face, 210b ... Second end face, 211b ... Pump housing, B1, B2, B3, B4 ... Boundary, J ... Central axis

Claims (6)

A pump mechanism having an inner rotor that is rotatable about an axially extending central axis and has external teeth, and an outer rotor that surrounds the inner rotor and has internal teeth that mesh with the external teeth.
A pump housing having a pump accommodating portion for accommodating the pump mechanism, and a suction portion and a discharge portion connected to the pump accommodating portion.
Equipped with
The pump housing is
A first end face that faces the pump mechanism in the axial direction on one side in the axial direction of the pump mechanism.
A second end face that faces the pump mechanism in the axial direction on the other side in the axial direction of the pump mechanism and sandwiches the pump mechanism in the axial direction with the first end face.
Have,
The suction part is
A first suction-side recess that is recessed from the first end surface to one side in the axial direction,
A second suction-side recess that is recessed from the second end surface to the other side in the axial direction,
Have,
The discharge part is
The first discharge-side recess, which is recessed from the first end surface to one side in the axial direction,
A second discharge-side recess that is recessed from the second end surface to the other side in the axial direction,
Have,
The bottom surface of the first suction-side recess and the bottom surface of the second suction-side recess each have a suction-side inclined surface that is inclined with respect to a surface intersecting the axial direction.
The bottom surface of the first discharge side recess and the bottom surface of the second discharge side recess each have a discharge side inclined surface that is inclined with respect to a surface intersecting the axial direction.
At least a part of the suction-side inclined surface of the first suction-side recess and the suction-side inclined surface of the second suction-side recess overlap each other when viewed from the axial direction, and the circumference around the central axis. Inclined toward one side of the direction and closer to each other in the axial direction,
At least a part of the discharge-side inclined surface of the first discharge-side recess and the discharge-side inclined surface of the second discharge-side recess overlap each other when viewed from the axial direction, and are directed to one side in the circumferential direction. Electric pumps that are tilted axially away from each other according to. The bottom surface of the first suction-side recess and the bottom surface of the second suction-side recess each have a suction-side flat surface that intersects the axial direction and is connected to the other side in the circumferential direction of the suction-side inclined surface.
The bottom surface of the first discharge side recess and the bottom surface of the second discharge side recess each have a discharge side flat surface that intersects the axial direction and is connected to one side in the circumferential direction of the discharge side inclined surface.
The boundary between the suction-side flat surface and the suction-side inclined surface in the first suction-side recess is such that the suction-side flat surface and the suction-side inclined surface in the second suction-side recess are viewed from the axial direction. Overlapping the border,
The boundary between the discharge-side flat surface and the discharge-side inclined surface in the first discharge-side recess is such that the discharge-side flat surface and the discharge-side inclined surface in the second discharge-side recess are viewed from the axial direction. Overlapping the border,
The electric pump according to claim 1. The electric pump according to claim 2, wherein the suction-side flat surface of the first suction-side recess and the discharge-side flat surface of the first discharge-side recess are arranged at the same positions in the axial direction. The first suction-side recess and the second suction-side recess each have a surface extending axially from one end in the circumferential direction of the suction-side inclined surface toward the pump mechanism.
The electric pump according to any one of claims 1 to 3. The first discharge-side recess and the second discharge-side recess each have a surface extending axially from the other end in the circumferential direction of the discharge-side inclined surface toward the pump mechanism.
The electric pump according to any one of claims 1 to 4. When viewed from the axial direction
The first suction-side recess, the second suction-side recess, the first discharge-side recess, and the second discharge-side recess extend in an arc shape along the circumferential direction around the central axis.
The electric pump according to any one of claims 1 to 5.

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