US20190301452A1

US20190301452A1 - Vane pump

Info

Publication number: US20190301452A1
Application number: US16/344,681
Authority: US
Inventors: Koichiro Akatsuka; Yoshiyuki Maki
Original assignee: KYB Corp
Current assignee: KYB Corp
Priority date: 2016-11-18
Filing date: 2017-11-08
Publication date: 2019-10-03
Also published as: DE112017005841T5; WO2018092645A1; JP6546895B2; CN109863306A; CN109863306B; JP2018080687A

Abstract

A vane pump includes a pump rotor having a through hole to which a driving shaft is coupled, a pump housing configured to accommodate the pump rotor and the cam ring, and a first side plate provided between the pump rotor and a bottom surface of the pump housing. The first side plate or the pump housing is formed with a projection, the projection is inserted into the through hole of the pump rotor.

Description

TECHNICAL FIELD

The present invention relates to a vane pump.

BACKGROUND ART

JP2013-136965A discloses an electric vane pump including an electric motor and a vane pump that is driven by a motive force from the electric motor.

SUMMARY OF INVENTION

The electric vane pump disclosed in JP2013-136965A may be produced by assembling the electric motor and the vane pump after the electric motor and the vane pump have been fabricated separately. In such a case, the electric motor and the vane pump are assembled by inserting a shaft of the electric motor into a through hole of a rotor of the vane pump.
However, because the rotor of the vane pump is in a freely movable state in a cam ring, an operation of inserting the shaft of the electric motor into the through hole of the rotor of the vane pump is complicated. Especially, when the vane pump and the electric motor are assembled in a state in which the diameter of the rotor is orientated so as to coincide with the vertical direction, the rotor falls into a bottom portion in the cam ring and the centers of the rotor and the cam ring are deviated greatly, and therefore, an operation of inserting the shaft of the electric motor into the through hole of the rotor of the vane pump becomes further complicated.
An object of the present invention is to improve assemblability of a vane pump.
According to one aspect of the present invention, a vane pump includes: a rotor having a through hole to which a driving shaft is coupled; a plurality of vanes provided so as to be freely reciprocatable in a radial direction with respect to the rotor; a cam ring configured to accommodate the rotor, the cam ring being configured such that tip-ends of the vanes slide on an inner circumferential surface of the cam ring as the rotor is rotated; a housing configured to accommodate the rotor and the cam ring; and a side plate provided between the rotor and a bottom surface of the housing. The side plate or the housing is formed with a projection, the projection being inserted into the through hole of the rotor.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a sectional view of a vane pump according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a state before an electric motor and the vane pump are assembled.

FIG. 3 is a sectional view of the vane pump according to a modification of the first embodiment of the present invention.

FIG. 4 is a side view of a first side plate.

FIG. 5 is a sectional view of the vane pump according to a second embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described below with reference to the drawings.

First Embodiment

A vane pump 100 according to a first embodiment of the present invention will be described with reference to FIG. 1.
The vane pump 100 is, for example, used as a hydraulic pressure source for supplying working oil (working fluid) to a hydraulic apparatus, such as a continuously variable transmission, etc., mounted on a vehicle.
The vane pump 100 is driven by a motive force from an electric motor 1. The vane pump 100 is coupled coaxially to the electric motor 1 via a driving shaft 4.
The electric motor 1 includes the driving shaft 4 that is rotatably supported by a motor housing 3 via bearings 2 a and 2 b, a motor rotor 5 that has a plurality of permanent magnets arranged in the circumferential direction and that is fixed to the driving shaft 4, and a stator 6 that is fixed to an inner circumference of the motor housing 3 and that is formed by winding a coil. The motor rotor 5 and the stator 6 are arranged concentrically, and there is a small gap between the motor rotor 5 and the stator 6.
The motor housing 3 includes a main body portion 3 a having a partially bottomed cylinder shape and a motor cover 3 b that closes an opening portion of the main body portion 3 a. The vane pump 100 is connected to the motor cover 3 b. The main body portion 3 a and the motor cover 3 b are assembled integrally by fitting an annular fitting portion 3 c formed in the motor cover 3 b into an inner circumferential surface of the main body portion 3 a.
The bearing 2 a is fixed to a bottom portion of the main body portion 3 a, and the bearing 2 b is fixed to an inner circumferential surface of a hollow portion 3 d of the motor cover 3 b. The driving shaft 4 is rotatably supported by two bearings 2 a and 2 b and is provided so as to extend by being inserted through the hollow portion 3 d of the motor cover 3 b. As described above, the driving shaft 4 is configured not as a part of the vane pump 100, but as a part of the electric motor 1.
The vane pump 100 includes a pump rotor 31 that is coupled to the driving shaft 4, a plurality of vanes 32 that are provided so as to be freely reciprocatable in the radial direction with respect to the pump rotor 31, a cam ring 33 that accommodates the pump rotor 31 and has an inner circumferential cam face on which tip-ends of the vanes 32 slide as the pump rotor 31 is rotated, and a pump housing 40 that accommodates the pump rotor 31 and the cam ring 33.
The driving shaft 4 is supported only by the bearings 2 a and 2 b provided in the electric motor 1, and a bearing for supporting the driving shaft 4 is not provided in the vane pump 100. A male spline 4 a is formed on an outer circumferential surface of an end portion of the driving shaft 4 on the vane pump 100 side.
The pump rotor 31 is an annular member, and a through hole 31 a, through which the driving shaft 4 is inserted, is formed at the center portion of the pump rotor 31 so as to penetrate therethrough in the axial direction. A female spline 31 b is formed on an inner circumferential surface of the through hole 31 a (see FIG. 2), and the male spline 4 a of the driving shaft 4 meshes with the female spline 31 b. As described above, the driving shaft 4 is coupled to the pump rotor 31 with a spline connection. In FIG. 1, illustration of the female spline 31 b is omitted.
In the cam ring 33, a plurality of pump chambers 34 are defined by an outer circumferential surface of the pump rotor 31, the cam face of the cam ring 33, and adjacent vanes 32.
The cam ring 33 is an annular member having the substantially oval shaped cam face with a minor axis and a major axis. The cam face of the cam ring 33 has two suction regions in which volumes of the pump chambers 34 are increased with the rotation of the pump rotor 31 and two discharge regions in which the volumes of the pump chambers 34 are decreased with the rotation of the pump rotor 31.
A first side plate 36 is arranged so as to be in contact with one side surfaces of the pump rotor 31 and the cam ring 33, and a second side plate 37 is arranged so as to be in contact with the other side surfaces of the pump rotor 31 and the cam ring 33. As described above, the first side plate 36 and the second side plate 37 are arranged so as to sandwich the pump rotor 31 and the cam ring 33 from both sides thereof, and thereby, the pump chambers 34 are defined.
The first side plate 36 is arranged between the pump rotor 31 and a bottom surface 40 b of the pump housing 40. The second side plate 37 is arranged between the pump rotor 31 and the motor cover 3 b.
The pump rotor 31, the cam ring 33, the first side plate 36, and the second side plate 37 are accommodated in a pump accommodating portion 40 a that is formed in the pump housing 40 so as to have a recessed shape. The pump housing 40 and the motor cover 3 b are fastened together with bolts, and an opening portion of the pump accommodating portion 40 a is closed the motor cover 3 b of the motor housing 3.
The first side plate 36 is a disc-shaped member, and has two arc-shaped discharge ports 36 a that are formed so as to penetrate through the first side plate 36. The discharge ports 36 a open so as to correspond to the discharge regions of the cam ring 33, and discharge the working oil in the pump chambers 34.
A projection 50, which is inserted into the through hole 31 a of the pump rotor 31, is formed on the first side plate 36 so as to be integral with the first side plate 36. The projection 50 is formed so as to project from the center portion of a side surface of the first side plate 36 and so as to have a cylinder shape concentric with the through hole 31 a of the pump rotor 31. A gap is formed between an outer circumferential surface 50 a of the projection 50 and the inner circumferential surface of the through hole 31 a, and a gap is also formed between an end surface 50 b of the projection 50 and an end surface 4 b of the driving shaft 4. In other words, when the driving shaft 4 and the pump rotor 31 are rotated, the projection 50 does not come into contact with the driving shaft 4 and the pump rotor 31. A function of the projection 50 will be described later in detail.
The second side plate 37 is an annular member, and a through hole 37 a, through which the driving shaft 4 is inserted, is formed at the center portion of the second side plate 37 so as to penetrate therethrough in the axial direction. In addition, two ark-shaped suction ports (not shown) are formed by being cut out in an outer circumference of the second side plate 37. The two suction ports open so as to correspond to the two suction regions of the cam ring 33, and guide the working oil to the pump chambers 34. The second side plate 37 is not essential to the configuration of the vane pump 100, and it may be possible to omit the second side plate 37. In such a case, the pump rotor 31 and the cam ring 33 are sandwiched by the first side plate 36 and the motor cover 3 b from both sides, and thereby, the pump chambers 34 are defined.
Relative rotation between the cam ring 33, the first side plate 36, and the second side plate 37 is restricted by two positioning pins 46. With such a configuration, the suction regions of the cam ring 33 and the suction ports of the second side plate 37 are aligned, and the discharge regions of the cam ring 33 and the discharge ports 36 a of the first side plate 36 are aligned.
The positioning pins 46 are inserted through the cam ring 33 and the second side plate 37 such that one end sides thereof are inserted into positioning holes 36 d that are formed in the first side plate 36 and the other end sides thereof are inserted into positioning holes 3 e that are formed in the motor cover 3 b. As described above, the cam ring 33, the first side plate 36, and the second side plate 37 are aligned by the positioning pins 46 with respect to the motor cover 3 b.
An inner circumferential surface of the hollow portion 3 d of the motor cover 3 b is provided with a seal member 45 with which an outer circumferential surface of the driving shaft 4 is in sliding contact. Leakage of the working oil from the vane pump 100 to the electric motor 1 is prevented by the seal member 45.
An annular high-pressure chamber 42 that communicates with the discharge ports 36 a of the first side plate 36 is formed in the bottom surface 40 b of the pump accommodating portion 40 a. The high-pressure chamber 42 is defined by the first side plate 36 that is arranged on the bottom surface 40 b of the pump accommodating portion 40 a. The high-pressure chamber 42 communicates with a discharge passage 41 that is formed so as to open at an outer surface of the pump housing 40.
A suction passage (not shown) that communicates with the suction ports of the second side plate 37 is also formed in the pump housing 40. The suction passage communicates with a tank that stores the working oil.
As the driving shaft 4 is rotated by driving the electric motor 1, the pump rotor 31 coupled to the driving shaft 4 is rotated, and thereby, the respective pump chambers 34 in the cam ring 33 suck the working oil through the suction ports of the second side plate 37 and discharge the working oil to the high-pressure chamber 42 through the discharge ports 36 a of the first side plate 36. The working oil in the high-pressure chamber 42 is supplied to a hydraulic apparatus through the discharge passage 41. As described above, the respective pump chambers 34 in the cam ring 33 suck and discharge the working oil by expansion and contraction caused by the rotation of the pump rotor 31.
Next, a method for assembling the electric motor 1 and the vane pump 100 will be described.
Production is performed by assembling the electric motor 1 and the vane pump 100 after the electric motor 1 and the vane pump 100 are fabricated separately. FIG. 2 is a diagram showing a state before the electric motor 1 and the vane pump 100 are assembled. As shown in FIG. 2, a description will be given of a case in which the electric motor 1 and the vane pump 100 are assembled in a state where the driving shaft 4 of the electric motor 1 is orientated perpendicular to the vertical direction.
The assembly of the electric motor 1 and the vane pump 100 is performed by inserting the driving shaft 4 of the electric motor 1 into the through hole 31 a of the pump rotor 31 of the vane pump 100, inserting the positioning pins 46 of the vane pump 100 into the positioning holes 3 e of the motor cover 3 b, and thereafter, fastening the pump housing 40 and the motor cover 3 b with bolts. A detailed described is given below.
Before describing the method of assembling the electric motor 1 and the vane pump 100 according to this embodiment, problems associated with the assembly will be described.
In the vane pump 100, before the electric motor 1 and the vane pump 100 are assembled, the pump rotor 31 is not fixed and is in a freely movable state in the cam ring 33, and so, the pump rotor 31 falls into a bottom portion in the cam ring 33 due to gravity. In this case, the pump rotor 31 moves in the vertical direction relative to the second side plate 37, and the position of the through hole 31 a of the pump rotor 31 is deviated from the position of the through hole 37 a of the second side plate 37. Thus, a state in which a part of the through hole 37 a of the second side plate 37 is blocked by the side surface of the pump rotor 31 is brought about. In such a case, even when the driving shaft 4 is to be inserted through the through hole 37 a of the second side plate 37 and inserted into the through hole 31 a of the pump rotor 31, because the end surface 4 b of the driving shaft 4 interferes with the side surface of the pump rotor 31, it becomes difficult to insert the driving shaft 4 into the through hole 31 a of the pump rotor 31. As described above, an operation of inserting the driving shaft 4 into the through hole 31 a of the pump rotor 31 becomes complicated. Especially, in a case in which the electric motor 1 and the vane pump 100 are assembled in a state where the diameter of the pump rotor 31 is orientated so as to coincide with the vertical direction, because the position of the through hole 31 a of the pump rotor 31 deviates greatly from the position of the through hole 37 a of the second side plate 37, the operation of inserting the driving shaft 4 into the through hole 31 a of the pump rotor 31 becomes further complicated.
As a countermeasure against this problem, in this embodiment, the first side plate 36 of the vane pump 100 is formed with the projection 50 that is to be inserted into the through hole 31 a of the pump rotor 31. With such a configuration, as shown in FIG. 2, in a state before the electric motor 1 and the vane pump 100 are assembled, the inner circumferential surface of the through hole 31 a of the pump rotor 31 is brought into contact with the outer circumferential surface 50 a of the projection 50, and thereby, the pump rotor 31 is supported by the projection 50 to restrict the fall of the pump rotor 31 in the cam ring 33. Therefore, the positional deviation between the through hole 31 a of the pump rotor 31 and the through hole 37 a of the second side plate 37 becomes small. Specifically, the positional deviation between the through hole 31 a of the pump rotor 31 and the through hole 37 a of the second side plate 37 corresponds to the gap between the outer circumferential surface 50 a of the projection 50 and the inner circumferential surface of the through hole 31 a in a state in which the electric motor 1 and the vane pump 100 are assembled (the state shown in FIG. 1).
In a state in which the pump rotor 31 is supported by the projection 50, as the driving shaft 4 is inserted through the through hole 37 a of the second side plate 37 and inserted into the through hole 31 a of the pump rotor 31, a tapered surface 4 c formed on an outer circumference edge of the end surface 4 b of the driving shaft 4 is brought into contact with an inner circumference edge 31 c of the through hole 31 a of the pump rotor 31, thereby lifting the pump rotor 31 upwards. Thus, the male spline 4 a of the driving shaft 4 enters inside the female spline 31 b, and connection between the male spline 4 a and the female spline 31 b is achieved.
In a state in which the male spline 4 a is connected to the female spline 31 b, in other words, in a state in which the driving shaft 4 is coupled to the pump rotor 31, as shown in FIG. 1, the projection 50 is arranged concentrically with the through hole 31 a of the pump rotor 31, and the gap is formed between the outer circumferential surface 50 a of the projection 50 and the inner circumferential surface of the through hole 31 a. In addition, the gap is also formed between the end surface 50 b of the projection 50 and the end surface 4 b of the driving shaft 4. Therefore, when the driving shaft 4 and the pump rotor 31 are rotated, the projection 50 does not interfere with the driving shaft 4 and the pump rotor 31.
As described above, the projection 50 has a function of aligning the pump rotor 31 in the cam ring 33 and facilitating the insertion of the driving shaft 4 into the through hole 31 a when the driving shaft 4 is inserted into the through hole 31 a of the pump rotor 31.
According to the above-described first embodiment, the advantages described below are afforded.
Because the first side plate 36 is formed with the projection 50 that is to be inserted into the through hole 31 a of the pump rotor 31, during the assembly of the electric motor 1 and the vane pump 100, the pump rotor 31 is aligned in the cam ring 33 by the projection 50 when the driving shaft 4 is inserted into the through hole 31 a of the pump rotor 31. Thus, the centers of the pump rotor 31 and the cam ring 33 are prevented from being deviated greatly, and thereby, it is possible to improve the assemblability of the vane pump 100.
A modification of the first embodiment will be described below.
(1) In the above-mentioned embodiment, a description has been given of the configuration in which the projection 50 is formed integrally with the first side plate 36. Instead of this configuration, as shown in FIG. 3, the projection 50 may be formed separately from the first side plate 36. Specifically, the cylinder-shaped projection 50 may be press-fitted into a groove 36 b formed in the side surface of the first side plate 36.
The side surface of the first side plate 36 on which the pump rotor 31 slides needs to be polished in order to improve sliding property of the pump rotor 31. In a case in which the projection 50 is formed integrally with the first side plate 36, it is difficult to perform this polishing operation. However, in a case in which the projection 50 is formed separately from the first side plate 36, because the first side plate 36 can be polished before press-fitting the projection 50 into the groove 36 b of the first side plate 36, workability of the polishing operation is improved.
(2) In the above-mentioned embodiment, a description has been given of the configuration in which the projection 50 is formed so as to project from the center portion of the side surface of the first side plate 36 and so as to have a cylinder shape concentric with the through hole 31 a of the pump rotor 31. Instead of the projection 50, as shown in FIG. 4, a plurality of cylinder shaped projections 51 may be formed on the side surface of the first side plate 36. FIG. 4 is a side view of the first side plate 36 viewed from the pump rotor 31 side. Three projections 51 are formed at 120 degree intervals on the same circle.
In a state in which the driving shaft 4 and the pump rotor 31 are coupled, there are gaps between outer circumferential surfaces of respective projections 51 and the inner circumferential surface of the through hole 31 a of the pump rotor 31. In addition, in a state before the electric motor 1 and the vane pump 100 are assembled, the inner circumferential surface of the through hole 31 a of the pump rotor 31 is brought into contact with any of the outer circumferential surfaces of the projections 51, and thereby, the pump rotor 31 is supported by the projections 51.
If an attaching orientation of the vane pump 100 is fixed in advance, it may be possible to provide only one projection 51 on the vertical line.
(3) The configuration is not limited to that in which the driving shaft 4 is rotated by the motive force from the electric motor 1. For example, a configuration in which the driving shaft 4 is rotated by a motive force from an engine may also be possible. In other words, the vane pump 100 is not limited to the configuration in which the vane pump 100 is assembled with the electric motor 1.

Second Embodiment

A vane pump 200 according to a second embodiment of the present invention will be described with reference to FIG. 5. In the following description, differences from the above-described first embodiment will be mainly described, and components that are the same as those in the vane pump 100 according to the above-described first embodiment are assigned the same reference numerals and descriptions thereof will be omitted. In FIG. 5, illustration of the electric motor 1 is omitted.
In contrast to the vane pump 100 according to the above-described first embodiment in which the first side plate 36 is formed with the projection 50 that is inserted into the through hole 31 a of the pump rotor 31, in the vane pump 200, a projection 60 that is to be inserted into the through hole 31 a of the pump rotor 31 is formed on the pump housing 40. The detail of the embodiment will be described below.
The projection 60 is formed integrally with the pump housing 40 so as to project from the center portion of the bottom surface 40 b of the pump housing 40. In a state in which the driving shaft 4 and the pump rotor 31 are coupled, the projection 60 is formed so as to be inserted through a through hole 36 c formed in the first side plate 36 and so as to have a cylinder shape concentric with the through hole 31 a of the pump rotor 31. A gap is formed between an outer circumferential surface 60 a of the projection 60 and the inner circumferential surface of the through hole 31 a, and a gap is also formed between an end surface 60 b of the projection 60 and the end surface 4 b of the driving shaft 4. In other words, when the driving shaft 4 and the pump rotor 31 are rotated, the projection 60 does not come into contact with the driving shaft 4 and the pump rotor 31.
The projection 60 may be formed separately from the pump housing 40 and may be press-fitted into a groove formed in the bottom surface 40 b of the pump housing 40.
In order to prevent a leakage of the working oil in the high-pressure chamber 42 from between the outer circumferential surface 60 a of the projection 60 and the through hole 36 c of the first side plate 36, a seal member 61 is provided between the bottom surface 40 b of the pump housing 40 and the first side plate 36 so as to surround an outer circumference of the projection 60.
Also with the above-described second embodiment, the operational advantages similar to those in the above-described first embodiment are afforded.
The configurations, operations, and effects of the embodiment according to the present invention will be collectively described below.
The vane pump (100, 200) includes: the pump rotor 31 having the through hole 31 a to which the driving shaft 4 is coupled; the plurality of vanes 32 provided so as to be freely reciprocatable in the radial direction with respect to the pump rotor 31; the cam ring 33 configured to accommodate the pump rotor 31, the cam ring 33 being configured such that the tip-ends of the vanes 32 slide on the inner circumferential surface of the cam ring 33 as the pump rotor 31 is rotated; the pump housing 40 configured to accommodate the pump rotor 31 and the cam ring 33; and the first side plate 36 provided between the pump rotor 31 and the bottom surface 40 b of the pump housing 40, wherein the first side plate 36 or the pump housing 40 is formed with the projection (50, 60), the projection (50, 60) being inserted into the through hole 31 a of the pump rotor 31.
With this configuration, because the projection (50, 60), which is to be inserted into the through hole 31 a of the pump rotor 31, is formed on the first side plate 36 or the pump housing 40, when the driving shaft 4 is inserted into the through hole 31 a of the pump rotor 31, the pump rotor 31 is aligned in the cam ring 33 by the projection (50, 60). Thus, the centers of the pump rotor 31 and the cam ring 33 are prevented from being deviated greatly, and thereby, it is possible to improve the assemblability of the vane pump (100, 200).
In addition, the projection (50, 60) is configured such that the pump rotor 31 is aligned in the cam ring 33 when the driving shaft 4 is inserted into the through hole 31 a of the pump rotor 31.
In addition, the projection 50 is formed to have a cylinder shape concentric with the through hole 31 a of the pump rotor 31, and a gap is formed between the outer circumferential surface 50 a of the projection 50 and the inner circumferential surface of the through hole 31 a, and a gap is formed between the end surface 50 b of the projection 50 and an end surface 4 b of the driving shaft 4.
With this configuration, when the driving shaft 4 and the pump rotor 31 are rotated, the projection 50 does not interfere with the driving shaft 4 and/or the pump rotor 31.
In addition, the projection 50 is press-fitted into the groove 36 b formed in the side surface of the first side plate 36.
With this configuration, because the projection 50 is formed separately from the first side plate 36, the first side plate 36 can be polished before the projection 50 is press-fitted into the groove 36 b of the first side plate 36, and therefore, workability of the polishing operation is improved.
In addition, the projection 60 is provided so as to project from the bottom surface 40 b of the pump housing 40 and so as to be inserted through the through hole 36 c formed in the first side plate 36.
Embodiments of this invention were described above, but the above embodiments are merely examples of applications of this invention, and the technical scope of this invention is not limited to the specific constitutions of the above embodiments.
This application claims priority based on Japanese Patent Application No. 2016-225216 filed with the Japan Patent Office on Nov. 18, 2016, the entire contents of which are incorporated into this specification.

Claims

1. A vane pump comprising:

a rotor having a through hole to which a driving shaft is coupled;

a plurality of vanes provided so as to be freely reciprocatable in a radial direction with respect to the rotor;

a cam ring configured to accommodate the rotor, the cam ring being configured such that tip-ends of the vanes slide on an inner circumferential surface of the cam ring as the rotor is rotated;

a housing configured to accommodate the rotor and the cam ring; and

a side plate provided between the rotor and a bottom surface of the housing, wherein

the side plate or the housing is formed with a projection, the projection being inserted into the through hole of the rotor, and

the projection is press-fitted into a groove formed in a side surface of the side plate.

2. The vane pump according to claim 1, wherein

the projection is configured such that the rotor is aligned in the cam ring when the driving shaft is inserted into the through hole of the rotor.

3. The vane pump according to claim 1, wherein

the projection is formed to have a cylinder shape concentric with the through hole of the rotor, and

a gap is formed between an outer circumferential surface of the projection and an inner circumferential surface of the through hole, and a gap is formed between an end surface of the projection and an end surface of the driving shaft.

4. (canceled)

5. (canceled)