JP2006348919A - Rotor device for pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To install and fix an inner rotor on a shaft in such a manner that the same does not slip in joining of the synthetic resin inner rotor and the shaft rotating the inner rotor, in an oil pump provided with the rotor such as the inner rotor and the outer rotor. <P>SOLUTION: This device comprises an inner rotor 3 made of a synthetic resin and the shaft A rotating the inner rotor 3. The shaft A is cast and formed when the inner rotor 3 is formed. A projecting locking part A<SB>1</SB>is formed in a contact zone which the shaft A passes through in relation to the inner rotor 3. The projecting locking part A<SB>1</SB>comprises a pin member 7 and a through-hole 6 formed on the shaft A. A resin receiver 7a in which melted resin flows is formed on the pin member 7, the pin member 7 is fitted in the through-hole 6 and both ends in a longitudinal direction thereof project out from an outer circumference surface of the shaft A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides an oil pump including a rotor such as an inner rotor and an outer rotor, in which the inner rotor is mounted on and fixed to the shaft so as not to idle by connecting the inner rotor made of synthetic resin and the shaft that rotates with the inner rotor. The present invention relates to a pump rotor device.

  In recent years, oil pumps using an inner rotor and an outer rotor made of trochoidal gears are often used in which the rotor is formed from a synthetic resin. A drive shaft is mounted on the inner rotor, and the inner rotor is rotated from the drive source via the drive shaft.

When a drive shaft is mounted on such an inner rotor made of synthetic resin, a structure using a key is different from a structure in which the drive shaft is mounted on a metal inner rotor. That is, the synthetic resin inner rotor and the metal drive shaft are completely different from each other in hardness, so that they do not have a mounting structure like a metal member. Further, the structure should not be such that play is generated between the drive shaft and the inner rotor.
No. 58-29183

  By the way, in the content currently disclosed by patent document 1, the drive shaft and inner rotor of an oil pump are connected through the parallel pin. The parallel pins are attached so that the drive shaft is orthogonal to the axial direction. This is fitted into the pin receiving hole of the same shape as the parallel pin formed in the inner rotor together with the parallel pin pushed through the drive shaft, and the drive shaft and the inner rotor are connected.

  It is considered that the parallel pin is inserted into the pin receiving hole so as not to be displaceable in the circumferential direction, and the end of the parallel pin protruding at the time of the internal fitting is inserted while being in contact with both walls of the pin receiving hole. The mechanical stress applied to the pin may cause damage or deformation of the parallel pin. As a result, uneven wear on the contact surface between the parallel pin and the inner rotor (pin receiving hole) and contact between the parallel pin and the pin receiving hole become defective, and noise is likely to occur. An object of the present invention is to improve the bonding strength between a metal drive shaft and a synthetic resin inner rotor, to facilitate processing, and to prevent backlash.

  In view of the above, the inventor has intensively and intensively studied to solve the above-mentioned problems. As a result, the invention of claim 1 comprises a synthetic resin inner rotor and a shaft for rotating the inner rotor. The above-mentioned problems have been solved by providing a pump rotor device in which the shaft is cast-molded together with the molding, and an undulating locking portion is formed in a contact region through which the shaft penetrates the inner rotor.

  According to a second aspect of the present invention, in the above-described configuration, the undulating engagement portion includes a pin member and a through hole formed in the shaft, and the pin member has a resin receiver into which molten resin flows. The above-described problems have been solved by forming a pump rotor device that is formed, the pin member is inserted into the through-hole, and both longitudinal ends thereof protrude from the outer peripheral surface of the shaft. According to a third aspect of the present invention, in the above-mentioned configuration, the pin member is a hollow tube, and the inside of the tube is a pump rotor device that serves as the resin receiver.

  According to a fourth aspect of the present invention, in the above-described configuration, the hollow pin as the pin member is a pump rotor device configured as a spring pin in which a split portion continuous in the axial direction is formed. Settled. Next, the invention of claim 5 solves the above-mentioned problem by providing a pump rotor device in which depressions are formed on both end surfaces in the longitudinal direction of the pin member and the depressions serve as resin receivers in the above-described configuration. . According to a sixth aspect of the present invention, in the above-described configuration, the undulating engagement portion is a bowl-shaped enormous portion protruding from an outer peripheral surface, and the enormous portion is formed into a non-circular shape. Thus, the above-mentioned problem has been solved.

  The invention according to claim 7 solves the above-mentioned problem by using the pump-like rotor device in which, in the above-described configuration, the undulating locking portion is formed with a locking recess portion on the outer peripheral surface. The invention of claim 8 solves the above-mentioned problems by providing a pump rotor device having a rough surface area made up of a large number of small protrusions around the undulating locking portion in the configuration described above. The invention of claim 9 solves the above-mentioned problem by using the pump rotor device in which the rough surface region is formed as a knurled portion in the above-described configuration.

  According to the first aspect of the present invention, the shaft is cast and molded together with the molding of the inner rotor made of synthetic resin, and the undulating locking portion is formed in the contact area between the inner rotor and the inner rotor through which the shaft penetrates. It is what. In the conventional process, when the rotor and the shaft are fixed via the pin so as not to run idle, the pin must be pushed in strongly by press-fitting means or the like. There was a possibility that stress was applied and the parallel pins were damaged or deformed. In the present invention, as described above, the shaft is cast-molded with respect to the inner rotor. In the process of assembling the inner rotor and the shaft, the shaft is mechanically connected to the inner rotor, the shaft, and the undulating engagement portion. There is almost no stress.

  Also, during the cooling process after molding the resin-molded inner rotor, the inner rotor contracts greatly due to the difference in linear expansion coefficient between the resin and metal, and the metal shaft has a low contraction rate. Therefore, a compressive force is always applied, and the effect of preventing the rotation of the undulating engagement portion is made more integrated, and the coupling strength between the shaft and the resin inner rotor is increased. Further, the undulating engagement portion of the shaft is cast into the inner rotor, so that the entire undulating engagement portion is covered inside the inner rotor.

  According to a second aspect of the present invention, the undulating engagement portion includes a pin member and a through hole formed in the shaft, and the pin member is fitted into the through hole. This makes it possible to easily assemble the undulating locking portion. Also, a resin receiver is formed on the pin member, and a molten resin material for molding the inner rotor flows into the resin receiver, and the resin bites into the resin receiver as the resin hardens. As a result, the inner rotor and the shaft can be made to be even stronger.

  Furthermore, the shaft is cast into the inner rotor together with the undulating locking portion, and the pin member only needs to be inserted so tightly that it can be manually pushed into the through hole. By casting into the rotor, the inner rotor is covered and the pin member is fixed, so that the inner rotor and the undulating locking portion of the shaft can be synergistically firmly joined to each other. Is.

  According to a third aspect of the present invention, since the pin member is a hollow tube, the resin also flows into the hollow pin, the unity is high, the coupling force between the pin member that is the hollow pin and the shaft, and the shaft and the inner rotor. It is possible to improve the bonding strength of both. Furthermore, since the hollow pin is press-fitted into the shaft and the inner rotor and the shaft are cast, the pin member can be prevented from falling off from the shaft during casting, and the manufacturing efficiency can be improved.

  In the invention of claim 4, since the spring pin can be elastically changed in the circumferential direction by using a split pin (spring pin) formed with a stripe-shaped split portion, The drilling of the through hole can be performed without high accuracy, and it is easy to perform press-fitting and molding, and the number of processing steps can be reduced. Further, the molten resin for molding the inner rotor at the time of casting also enters from the split part of the spring pin to improve the manufacturing efficiency. Further, in the invention of claim 5, a depression is formed on both end surfaces in the longitudinal direction of the pin member, and the depression is used as a resin receiver. The resin bites into the depression, and the inner rotor and the shaft are firmly bonded. It can be.

  The invention according to claim 6 is that the undulating engagement portion is a bowl-shaped enormous portion protruding from the outer peripheral surface, and the enormous portion is formed in a non-circular shape, whereby the undulation engagement portion is formed into an inner rotor. As a result, the inner rotor and the shaft can be more firmly coupled. In the invention according to claim 7, the undulating locking part is formed with a locking dent on the outer peripheral surface, so that the molten resin of the inner rotor at the time of casting enters the locking dent, The inner rotor and the shaft can be firmly coupled, and the volume of the inner rotor can be substantially increased, so that the mechanical strength of the inner rotor can be increased.

  According to an eighth aspect of the present invention, there is provided a rough surface region including a plurality of small protrusions around the undulating engagement portion, and the biting between the inner rotor that cools and hardens from casting and the shaft is interposed through the rough surface region. As a result, the entire contact surface between the inner rotor and the shaft becomes good, and the inner rotor and the shaft can be firmly connected. According to a ninth aspect of the present invention, the undulating engagement portion can be made good over substantially the entire contact surface between the inner rotor and the shaft by forming the rough surface region in a knurled portion. At the same time, knurling that is regularly formed can be machine-molded and can improve manufacturing efficiency.

  Hereinafter, the present invention will be described with reference to the drawings. First, as shown in FIG. 1 (A), the oil pump according to the present invention has a pump body 1, a pump cover 2, an inner rotor 3 and an outer rotor 4 made of synthetic resin, and a shaft that rotates the inner rotor 3. A is made of metal. The pump body 1 and the pump cover 2 may be formed of a metal material such as aluminum or iron. The pump body 1 and the pump cover 2 are coupled by a set screw to form a pump casing.

  Although not shown in the drawing, a partition portion, a suction port, and a discharge port are formed in the pump body 1. Further, as shown in FIG. 4, the inner rotor 3 and the outer rotor 4 have, for example, a trochoidal tooth profile. The inner rotor 3 has a trochoidal tooth profile on the outer periphery, and the outer rotor 4 has an inner periphery side. A trochoidal tooth profile is formed. The number of teeth of the inner rotor 3 is smaller than the number of teeth of the trochoidal tooth profile of the outer rotor 4. The outer rotor 4 is also rotated by the rotation of the inner rotor 3, and the trochoidal tooth profile of the inner rotor 3 and the trochoidal tooth profile of the outer rotor 4 are in contact with each other to form a gap chamber or cell between teeth. The fluid is confined in the cell, and the fluid is transferred along with the rotation of the inner rotor 3 and the outer rotor 4.

Further, as shown in FIGS. 1B and 1C, the shaft A is mounted at the radial center of the inner rotor 3. The shaft A is mounted by casting when the inner rotor 3 is resin-molded through a mold or the like. That is, the shaft A is arranged in advance in the mold, the molten resin is poured from the mold gate, the resin hardens in the mold, and the shaft A is firmly fixed. The shaft A is for rotating the inner rotor 3, and a shaft-like main body 5 of the shaft A is formed with an undulating engagement portion A ₁ . The undulating engagement portion A ₁ is formed within the contact range in the axial direction with the inner rotor 3, and the resin enters the protrusions or recesses of the undulation engagement portion A ₁ , thereby The shaft A can be coupled very firmly.

There are a plurality of embodiments in the undulating engagement portion A ₁ of the shaft A. As the first embodiment of the undulating engagement portion A ₁ , as shown in FIGS. 1B, 1 C, and 2, the shaft A is formed in a contact region with the inner rotor 3 of the shaft body 5. The through hole 6 and the pin member 7 are formed. The through hole 6 is formed orthogonal to the axial direction of the shaft body 5 (including substantially orthogonal). The pin member 7 is penetrated with respect to the through hole 6, and both end portions in the axial direction of the pin member 7 are projected from the outer peripheral surface of the shaft body 5.

The pin member 7 may be fixed to the through hole 6 by press-fitting. The cross-sectional shape of the through-hole 6 is usually a circle although it depends on the cross-sectional shape of the pin member 7. Further, due to the press-fitting, the inner diameter of the through-hole 6 is slightly smaller than the outer diameter of the pin member 7, and a dimensional tolerance for tight fitting is applied. As a result, the both ends in the longitudinal direction of the pin member 7 penetrating the shaft main body 5 project, whereby the undulating locking portion A ₁ is configured. In this way, the pin member 7 is passed through the through-hole 6, and both end portions in the longitudinal direction of the pin member 7 protrude from the outer peripheral surface of the shaft body 5 by an appropriate length, and the gold of the inner rotor 3 By casting at the time of resin molding by the mold, the shaft A can be firmly attached to the inner rotor 3.

  A resin receiver 7 a is formed on the pin member 7. The resin receiver 7a is a portion into which the molten resin flows when the shaft A is cast into the inner rotor 3, and when the molten resin is cured and the resin molding of the inner rotor 3 is completed, The resin receiver 7a and the resin that has flowed into the resin receiver 7a and hardened firmly bond the inner rotor 3 and the shaft A together.

There are various types of the resin receiver 7a. As shown in FIGS. 1 and 2, the first type of the resin receiver 7a is a hollow pin having a hollow cylindrical or tubular shape with a pin member 7 removed. The pipe-shaped resin receiver 7a ₁ is used. In this hollow pin, the pipe-shaped resin receiver 7a ₁ is tubular and melted as shown in FIGS. 3A to 3C when the shaft A is cast into the inner rotor 3. When the resin r flows into the pipe-shaped resin receiver 7a ₁ , the locking force between the inner rotor 3 and the undulating locking portion A ₁ of the shaft A is further strengthened, and the coupling strength is increased. The number of the pin members 7 is usually one, but the number may be two or three or more as necessary. When a plurality of pin members 7 are used, it is more preferable that the insertion structure is arranged so that the pin members 7 intersect each other.

  In the present invention, as described above, since the pin member 7 (including the hollow pin) is press-fitted before molding, the pin member 7 can be removed from the shaft A when the shaft A is placed. Therefore, integral molding by casting into the inner rotor 3 is facilitated. Further, when the pin member 7 is press-fitted into the through hole 6 of the shaft A, the end portion of the pin member 7 protrudes from both sides in the diameter direction of the outer peripheral surface of the shaft A (the shaft body 5). Therefore, it is easy to adjust the protruding amount of the both side portions, and the protruding length of the pin member 7 on both sides in the diameter direction of the shaft A can be made equal to each other.

  As the pin member 7, as shown in FIG. 5A, a spring pin (split pin) in which a streak-shaped split portion 7 b continuous in the axial direction is formed may be used. By using the spring pin, the shaft A can be easily inserted into the through hole 6. The pin member 7 used as the spring pin is formed with a split part 7b having a gap along the axial direction. The split part 7b is an elastic member in the circumferential direction. Since it becomes flexible, high accuracy is not required for processing the inner diameter of the through hole 6 of the shaft A. That is, since the processing error of the through-hole 6 can be absorbed by the elasticity of the pin member 7 as a spring pin, it is easy to press-fit and processing is easy [see FIG. Efficiency can be increased. Further, when the pin member 7 is a spring pin, at the time of casting, the molten resin r forming the inner rotor 3 also enters from the split portion 7b of the spring pin, thereby improving the manufacturing efficiency [ See FIG. 5C].

Next, as the second type of the resin receiving 7a, and is formed as 7a ₂ indentations at both axial ends portion of the pin member 7. In which molten resin enters into the recess 7a _2. As the first shape of the recess 7a ₂ , as shown in FIGS. 6A and 6B, a shaft end recess having a shallow hole shape that does not penetrate along the axial direction on both end surfaces of the pin member 7 in the axial direction is provided. It is formed. Further, as the second shape of the recess 7a _2, FIG. 7 (A), was formed (B), the as radial muscle groove along its diameter direction at both axial ends portion of the pin member 7 Things exist. Furthermore, as the third shape of the recess 7a ₂ , as shown in FIGS. 8A and 8B, the pin member 7 is formed as an axial streak groove along the axial direction at both ends in the axial direction. Things exist.

Next, a second embodiment of the contoured engagement portion A _1. As the undulating engagement portion A ₁ , a bowl-shaped enormous portion 8 protruding in the radial direction is formed at a portion engaged with the inner rotor 3. As the planar shape of the enormous portion 8, as shown in FIGS. 9A and 9C, it is a substantially “0” shape, a capsule shape, or an oval shape. The enormous portion 8 has a pair of opposed outer peripheral surfaces in the diametrical direction of the shaft A (shaft body 5) thereof as flat portions, and the other outer peripheral surface orthogonal to the one set of flat portions is a circumferential side surface. Is formed. The interval between the opposing flat portions is formed to be substantially equal to the diameter of the shaft body 5 of the shaft A. The enormous portion 8 may be formed when the shaft A is formed by a technique such as sintering or die casting. However, the enormous portion 8 is pressed into the shaft body 5 of the shaft A as a separate member from the shaft A. Are not limited to the production thereof.

  The protruding portion in the radial direction of the shaft A of the enormous portion 8 may be formed in a plurality of radial positions instead of two. Further, as the shape of the enormous portion 8, it is formed in a square shape such as a square or a rectangle as seen from the axial front of the shaft A (see FIG. 10B), or a bolt head, a nut or the like. Thus, it may be a hexagonal shape (see FIG. 10 (A)) or may be a polygonal shape larger than that, and the outer peripheral surface of the enormous portion 8 is formed as a polygonal surface.

As a third embodiment of the undulating locking portion A ₁ , as shown in FIGS. 11A and 11B, a locking recess 9 is formed in the shaft body 5 of the shaft A that is recessed in the radial direction. It has been done. The locking recess 9 has a groove shape, and faces the both sides in the diameter direction of the shaft A (the shaft body 5) in a direction orthogonal to the longitudinal direction of the shaft A (the shaft body 5). Two are formed. The bottom surface of the locking recess 9 is linear and flat. Both side wall surfaces in the width direction of the bottom surface are surfaces perpendicular to the longitudinal direction of the shaft A.

  Furthermore, the bottom shape of the locking recess 9 may be an arcuate surface. Further, the locking recesses 9 may be arranged at a plurality of locations in the circumferential direction of the cross section of the shaft A instead of at two locations in the radial direction of the shaft A. Further, the locking recess 9 is formed with a groove in the circumferential direction of the shaft A, and the bottom surface thereof has a circumferential shape, a cross section orthogonal to the axial direction has a quadrangular shape, or a hexagonal shape. It is good also as a shape.

Next, as the fourth embodiment, as shown in FIG. 12 (A), around the contoured engagement portion A _1, and a number of small projections 10a, 10a, ... and the roughened area 10 consisting of, the The small protrusions 10a, 10a,... Are formed by forming a large number of small protrusions 10a, 10a,. By forming this rough surface region 10 on the shaft A across the contact surface with the inner rotor, as shown in FIG. 12 (B), the biting between the inner rotor 3 and the shaft A by casting becomes stronger. The coupling force between the rotor 3 and the shaft A can be extremely increased. FIG. 12A shows the pin member 7 mounted on the rough surface region 10. Further, in the rough surface region 10, as shown in FIGS. 13 (A) and 13 (B), the knurled processing is regularly formed by forming the knurled portion 10b. Can also be machine-molded to improve production efficiency. FIG. 13A shows the pin member 7 mounted on the rough surface region 10 having the knurled portion 10b.

As described above, the shaft A is cast-molded together with the undulating locking portion A ₁ with respect to the inner rotor 3. In the integral molding of the inner rotor 3 and the shaft A, the linear expansion coefficient of the metal material such as iron and the synthetic resin is different, so that the undulating engagement portion A ₁ of the shaft A is cast on the inner rotor 3. In the cooling process, the inner rotor 3 which is a resin contracts greatly, but the metal shaft A has a small contraction rate. Therefore, the inner rotor 3 has a shaft A (inward in the radial direction). Therefore, a compressive force is always applied. And it becomes more integrated with the anti-rotation effect by the undulating engagement portion A ₁ , and the coupling strength between the shaft A and the inner rotor 3 is increased.

  In the present invention, the oil pump including the inner rotor 3 and the outer rotor 4 having the trochoidal tooth profile has been described. However, as long as the rotor is made of synthetic resin, the present invention may be applied to various gear pumps.

(A) is a vertical side view of the pump according to the present invention, (B) is a vertical side view in which a shaft is cast into the inner rotor as the first embodiment of the undulating locking portion, and (C) is an X of (B). ₁ -X ₁ is a sectional view taken along the line. (A) is a perspective view of the shaft to which the pin member is mounted, and (B) is a perspective view in a state where the shaft and the pin member are separated. (A) thru | or (C) are process drawings which expanded the principal part which shows the state which the molten resin entered into the resin receptacle of a pin member, (D) is principal part sectional drawing of the state which resin entered the pin member appropriately. is there. It is a top view of a pump body. (A) is a perspective view in which the pin member is a spring pin, (B) is an operational view showing a state in which an error between the pin member and the through hole of the shaft is absorbed by the elasticity of the pin member, and (C) is a pin member It is an effect | action figure of the state into which the molten resin entered from the split part. (A) is a perspective view of the pin member made into the hollow which provided the resin receiver in the axial direction both ends, (B) is a principal part expanded sectional view of the state which resin entered the resin receiver. (A) is a perspective view of the pin member made into the groove shape of the diameter direction which provided the resin receiver in the axial direction both ends, (B) is a principal part expanded sectional view of the state which resin entered the resin receiver. (A) is a perspective view of the pin member made into the groove shape of the axial direction which provided the resin receiver in the axial direction both ends, (B) is a principal part expanded sectional view of the state which resin entered the resin receiver. (A) is a perspective view of a main part of a shaft in which a huge part is formed as a second embodiment of the shaft-like locking part of the shaft, (B) is a longitudinal side view in which the shaft is cast and formed on the inner rotor, (C ) Is a cross-sectional view taken along the line X ₂ -X ₂ in FIG. (A) is the principal part perspective view of the pin member which made the enormous part hexagonal shape, (B) is the principal part perspective view of the pin member which made the enormous part square. (A) is the principal part perspective view of the shaft in which the latching recessed part was formed as 3rd Embodiment of an undulating latching part, (B) is the principal part longitudinal cross-sectional front view state in which the resin entered the latching recessed part. It is. (A) is the principal part perspective view of the shaft in which the rough surface area | region which consists of many small protrusions was formed as 4th Embodiment of an uneven | corrugated shaped latching | locking part, (B) is the state where resin was biting into the rough surface area | region. It is a principal part expanded sectional view. (A) is the principal part perspective view of the shaft in which the rough surface area made into the knurled shape was formed as 4th embodiment of an uneven | corrugated shaped latching | locking part, (B) is the principal part state in which the resin got bitten in the rough surface area | region. It is an expanded sectional view.

Explanation of symbols

3 ... inner rotor, A ... shaft, A ₁ ... contoured engagement section, 7 ... pin member,
Holes ... 6, the resin receiving ... 7a, split unit ... 7b, recess ... 7a _2, ampullary ... 8,
9: Locking recess, 10a: Small protrusion, 10 ... Rough surface region, 10b ... Knurled portion.

Claims (9)

  It consists of an inner rotor made of synthetic resin and a shaft that rotates the inner rotor, and the shaft is cast and molded together with the molding of the inner rotor. A rotor device for a pump, wherein a stop portion is formed.   In Claim 1, the said undulation-shaped latching | locking part consists of a pin member and the through-hole formed in the said shaft, The resin receptacle into which the molten resin flows in is formed in the said pin member, The said through-hole is formed in it. The pump rotor device, wherein the pin member is inserted, and both longitudinal ends thereof protrude from the outer peripheral surface of the shaft.   3. The pump rotor device according to claim 2, wherein the pin member is a hollow tube, and the inside of the tube is the resin receiver.   4. The pump rotor device according to claim 3, wherein the hollow pin as the pin member is a spring pin in which a split portion continuous along the axial direction is formed.   3. The pump rotor device according to claim 2, wherein dents are formed on both end surfaces in the longitudinal direction of the pin member, and the dents are used as resin receivers.   2. The pump rotor device according to claim 1, wherein the undulating engaging portion is a bowl-shaped enormous portion protruding from an outer peripheral surface, and the enormous portion is formed in a non-circular shape.   The pump rotor device according to claim 1, wherein the undulating locking portion has a locking recess formed on an outer peripheral surface.   In the description of any one of claims 1, 2, 3, 4, 5, 6 and 7, a rough surface region comprising a large number of small protrusions is provided around the undulating engagement portion. The pump rotor device.   9. The pump rotor device according to claim 8, wherein the rough surface region is formed as a knurled portion.

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