JPS5893978A - Variable capacity vane pump - Google Patents

Abstract

PURPOSE:To simplify the structure, simplify the orifice changes, and obtain optional flow characteristics in such a way that an orifice is formed between the bore wall in the pump housing and the outer periphery of a moving ring, and a fluid chamber on the both is comparted into two working chambers. CONSTITUTION:A moving ring 21 to hold a rotor 23 inside is given impetus by a relief valve 30 and a flow regulating spring 25 to the left as shown in the figure, and it is brought into contact with a miximum eccentricity rate adjustable screw 26. A seal pin 27 is inserted into a groove 21a of the moving ring 21, and it is brought into contact with the upper part circumferential wall of a guide housing 12 in liquid-tight condition. A void regulating member 28 is inserted into a groove 12b which is provided on the lower part circumferential wall of the guide housing 12, an orifice 0 is formed between the moving ring 21 and said part, and a fluid chamber R is comparated into two chambers r1, r2. Since the inside 28a of the void regulating member 28 is formed in arciform shape having the pin 27 as its center, throttling opening degree remains constant regardless of the eccentricity rate of the moving ring 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a variable displacement vane pump in which the discharge capacity is varied by changing the eccentricity of a movable ring, which is housed in an inner hole of a pump housing so as to be movable in the radial direction, with respect to the rotor. Seki-f le.

Conventionally, in this type of variable displacement vane pump, the fluid chamber formed between the inner circumferential wall of the pump housing and the outer circumference of the movable ring is divided into two, and an orifice is provided in the discharge (m) path that communicates with one of the divided chambers. It has been proposed that the supply flow rate to the moving equipment before and after the orifice is controlled to be constant by applying a force to the other compartment on the downstream side 1(-) of the orifice. however,
Such a variable displacement vane pump includes means for dividing the fluid chamber formed between the inner circumferential wall of the bomb housing and the outer circumference of the movable ring into two, means for forming an orifice,
Each means itself, such as the means for applying the pressure before and after the orifice to the two compartments, is complicated, and there is a disadvantage that the configuration of the vane pump becomes extremely complicated.

The present invention was made by paying attention to such actual situation.
The main purpose of this is to form an orifice between the inner circumferential wall of the pump housing and the outer circumferential surface of the movable ring, and to open the fluid chamber between the pump housing and the movable ring.
The purpose of the present invention is to provide a variable displacement vane pump which is structured so as to be divided into two working chambers, and which has a simple structure.Furthermore, it is possible to provide a variable displacement vane pump which can easily change the orifice and obtain desired flow characteristics. It is about providing.

The present invention will be explained below based on the drawings. Figs. 1 and 2 show a first embodiment of a variable displacement vane pump according to the present invention. The pump housing 10 of this variable displacement rectangular vane pump (hereinafter sometimes referred to as vane pump) is composed of a front housing 11, a guide housing 12, and a rear housing 16. An inner hole 12a is formed to accommodate a rotor 23 having a movable ring 21 and a number of vanes 22.

The movable ring 21 is connected to the inner hole 12a of the guide housing 12.
It is a perfect circle with a small diameter and is housed in the inner hole 12a so as to be movable in the radial direction, forming a fluid chamber R between the peripheral wall of the inner hole 12a and the outer periphery of the movable ring 21. ing. Further, the rotor 23 is spline-fitted to one end of a rotating shaft 24 that is liquid-tightly and rotatably supported by the front housing 11, and is housed inside the movable ring 21 so that the inner periphery of the movable ring 21 and the rotor 23 are connected to each other. A pump chamber P is formed between the outer peripheries. The movable ring 21 is biased to the left in the figure by a flow meter adjustment pressure spring 25 interposed between the outer periphery of the movable ring 21 and a relief valve O disposed on the second right side in the figure of the guide housing 12. The guide housing 12 is in contact with a maximum eccentricity regulating screw 26 disposed on the second left side of the guide housing 12 in the figure. As a result, movable ring 2
1 is eccentric by the maximum amount with respect to rotor 2.

On the other hand, on the inner surface of the front housing 11, a suction boat 11/' and a discharge boat 11b are formed. The suction boat 11a communicates with a suction passage 11C provided in the front housing 11 and the suction area of the pump chamber P, and the discharge boat 11b communicates with the discharge area of the pump chamber P and the fluid chamber R.

In other words, an elongated hole 11d provided on the inner surface of the front housing 11 and an elongated hole 14 provided on the inner surface of the pressure plate 14.
Both ends of a seal pin 27 extending in the axial direction are fitted into a. This seal bin 27 is attached to the guide housing 1
The inner hole 12a (1') of 2 is in close fluid-tight contact with the upper peripheral wall. In addition, a seal pin 27 on the outer periphery of the movable ring 21
A fitting groove 21a into which the seal bin 27 can be fitted is formed in the axial direction at a portion facing the seal bin 27. This movable ring 2
1 is pushed upward by the fluid pressure of the pump chamber P to fit the fitting groove 21a into the seal pin 27.

4- Thereby, the seal bin 27 supports the movable ring 21 so as to be able to swing in the left-right direction in the second figure, and also connects between the inner hole circumferential wall of the guide housing 12 and the outer circumference of the movable ring 21 at the supporting portion. It is sealed. Further, a fitting recess 12b extending in the axial direction is formed in the lower peripheral wall of the inner hole 12a of the guide housing 12.
A gap adjustment member 28 is fitted and attached to b. This gap adjustment member 28 slightly protrudes into the fluid chamber R,
An orifice 0 is formed between the inner surface 28a and the outer circumferential surface of the movable ring 21, and a first working chamber r into which the discharge boat 11b opens the fluid chamber R together with the seal bottle 27.
It is divided into a working chamber r2 and a second working chamber r2 in which the discharge hole 12C is opened. These two working chambers r and r2 communicate with each other through the entire orifice O. i! In addition, the inner surface 28a of the gap adjustment member 28 is formed in an arc shape with the seal pin 27 as the center of curvature, and even if the amount of eccentricity of the movable ring 21 with respect to the rotor 2 changes due to the swinging of the movable ring 21, the orifice does not open. It is configured so that the temperature is always constant.

In the vane pump configured in this way, the movable ring 21 is eccentric by the maximum amount when not driven, as shown in FIG. The pump chamber 1' is pumped through the circuit 11C and the suction boat 11a through the pump chamber 1'.
It is discharged into the working chamber r, flows through the orifice O into the second working chamber r2, and is supplied to an appropriate fluid operating device through the discharge hole 12C and a discharge passage (not shown). During this time, when the rotational speed of the rotating shaft 24 and the rotor 23 (pump rotational speed) increases and the amount of pressure fluid discharged to the first working chamber r1 increases, the first working chamber r and the second working chamber r
The movable ring 21 is moved by the spring 2 due to the differential pressure generated between the two.
5 to the right in the second drawing.

As a result, the amount of eccentricity of the movable ring 21 with respect to the rotor 26 decreases in accordance with the increase in differential pressure (increase in pump rotational speed) K, reducing the discharge amount per pump rotation, and the pump operates regardless of the increase in pump rotational speed. Controls the amount of pressure fluid supplied to equipment at a constant level. In other words, the relationship between the supply flow rate of pressure fluid and the pump rotation speed of the vane pump is as follows:
The graph is as shown by the solid line (A) in the figure, and it has flow characteristics similar to those of the conventional variable displacement vane pump. Note that when the pressure in the second working chamber r2 exceeds the set pressure, the spool 31 of the relief valve 60 is displaced against the spring 62 to drain the pressure fluid in the second working chamber r2.

In this way, the vane pump has flow characteristics similar to those of conventional variable displacement vane pumps, but
Seal bottle 2 provided in a component of the pump housing 10
7 and the gap adjustment member 28, the pump housing 10,
To avoid making major changes to the movable ring 21, etc., the fluid chamber Tt is divided into two chambers R and R2, and an orifice 0 is installed to create a differential pressure in both chambers R and R2.
The structure of the vane pump is extremely small compared to conventional variable displacement vane pumps.

Note that the configuration in which the movable ring 21 is supported in a swingable manner by the seal bin 27 is not necessarily an essential requirement for the present invention, and the movable ring 21 may be configured to be linearly displaced.

FIG. 6 shows a second embodiment of the invention. The vane pump shown in this second embodiment has the same structure as the vane pump in the first embodiment except that the gap adjustment member is changed. In the vane pump gap adjustment member 28 shown in the second embodiment, the inner surface 28a is formed in an inclined shape, and the amount of protrusion of the inner surface 28a into the fluid chamber R gradually increases as it moves to the right in the figure. It is supposed to be done. The opening degree of the orifice 0 formed between the movable ring 21 and the outer peripheral surface of the movable ring 21 gradually decreases as the movable ring 21 swings to the right in the drawing. Therefore, in this vane pump, the differential pressure generated between the two chambers '1+'2 becomes larger than the differential pressure generated in accordance with the pump rotation speed, and the movable ring 21 is swung, causing the pressure to be supplied to the operating equipment. The fluid is the fourth
As shown by the two-dot chain line (n) in the figure, it gradually decreases as the pump rotation speed increases. In addition, this gap adjustment member 28
', using a gap adjusting member with a different shape on the inner (11) surface, the orifice 1 can be adjusted according to the amount of swing of the movable ring 21.
A total change of 11 degrees will reduce any flow rate characteristic by 71 degrees.

As described above, the present invention provides a fluid chamber formed in the inner circumferential wall of the pump housing and the outer circumferential surface of the movable ring constituting a variable displacement vane pump, and between the inner circumference of the movable ring and the outer circumference of the rotor. A discharge boat communicating with the discharge region of the pump chamber formed and a discharge hole communicating with the outside are respectively opened, and a movable ring is inserted between the discharge boat and the discharge hole of the pump housing to connect the inner hole circumferential wall of the pump housing. A sealing portion is provided that is in fluid-tight contact with the pump housing, and a gap adjustment member is provided on the opposite side of the seal portion on the inner wall of the inner hole of the pump housing. Its structural feature lies in the fact that it was formed. Therefore, according to the present invention, it is possible to provide a variable displacement vane pump with a simpler flow control configuration than the conventional one. Further, according to the present invention, since the gap adjustment member is arranged as described above, it is possible to obtain any flow rate characteristic by utilizing the displacement of the movable ring, and it is possible to easily create a variable displacement vane pump having any flow rate characteristic. can be provided.

[Brief explanation of the drawing]

1 is a longitudinal cross-sectional view of a vane pump according to a first embodiment of the present invention, FIG. 2 is a longitudinal cross-sectional view taken along line I-1 in FIG. 1, and FIG.
The figure is a longitudinal sectional view corresponding to FIG. 2 of the vane pump according to the second embodiment, and FIG. 4 is a graph showing the flow characteristics of both vane pumps. Explanation of symbols 10...Pump housing, 11a...Suction boat, 11b...Discharge boat, 12a...Inner hole, 12C...Discharge hole, 21... Movable ring, 2
6...Rotor, 25...Spring, 27...
・Seal...inner surface, 0,0...orifice,
P...Pump room, R...Fluid chamber, r engineering, r2...
...action chamber. 11- Figure 1 Figure 2 jzb 26 12a Figure 3

Claims (1)

[Claims] A rotor having a large number of vanes is housed inside a movable ring that is movable in the radial direction in the inner hole of the pump housing, and the movable ring is attached to one side by a spring assembly that abuts the outer periphery of the movable ring. a pump that is biased eccentrically with respect to the rotor, and that is formed between the inner circumference of the movable ring and the outer circumference of the rotor, in a fluid chamber formed between the inner circumferential wall of the pump housing and the outer circumference of the movable ring; In a variable displacement vane pump comprising a discharge boat communicating with a discharge area of a chamber and a discharge hole communicating with the outside, the movable ring is placed between the discharge boat and the discharge hole on the inner circumferential wall of the pump housing. A seal portion is provided in fluid-tight contact with the inner peripheral wall of the pump housing, and a gap adjustment 1゛πζ (A) is provided at a portion of the inner circumferential wall of the inner hole of the pump housing opposite to the seal portion, and the inner peripheral surface of the gap adjustment member and the The fluid chamber is divided into two working chambers by forming an orifice with the outer periphery of the movable ring, and one of the working chambers is communicated with the discharge boat and the other with the discharge hole. Capacitive vane pump.