JP3312464B2 - Vane pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vane pump.

[0002]

2. Description of the Related Art In a conventional vane pump, as shown in FIG. 4, a rotary shaft 3 is rotatably supported on a housing 1 via a bearing 2, and outer peripheral end surfaces of a side plate 4 and a cam ring 5 are attached to the housing 1. The rotor 6 is fitted to the rotary shaft 3 and is rotatably connected thereto. Here, the side plate 4 and the cam ring 5 are supported in the radial direction by pins (not shown) that are pressed into the housing 1. Here, a pair of discharge ports 9 are formed in the side plate 4, and the other discharge port 9 is formed at a point symmetrical position about the axis of the rotating shaft 3. Similarly, suction ports (not shown) are formed in the side plate 9 at point-symmetric positions about the axis of the rotating shaft 3.

In the above configuration, the housing 1 is machined as follows in order to ensure the coaxiality of the side plate 4 with respect to the rotating shaft 3. First, a shaft hole 1a is formed in the housing 1 from the left side in FIG. Thereafter, the bearing 2 is pressed into the shaft hole 1a from the left in FIG. Next, the inner circumference of the bearing 2 is machined to the outer diameter φd ′ of the rotating shaft 3.

[0004] Next, from the right side in FIG.
With processing the first guide surface 7 in the housing 1 with a diameter [phi] D ₁ of the outer peripheral surface of the at side plate small-diameter portion 4a of the diameter [phi] D ₂ which is formed in a concave shape on the housing 1 side end face of the 4 2
The guide surface 8 is processed. When assembling the side plate 4 to the housing 1 processed as described above, the side plate 4 is rotated by guiding the side plate 4 with reference to one of the first guide surface 7 and the second guide surface 8. The coaxiality with the shaft 3 is ensured.

Here, the processing of the inner diameter φd ′ of the bearing 2 is described with reference to FIG.
While the work is performed from the middle left direction, the processing of the first guide surface 7 and the second guide surface 8 for guiding the side plate 4 is performed as shown in FIG.
From the middle right direction, as shown in FIG.
This is because the diameter φD _{3 of the} hole 1 b through which the rotary shaft 3 of the housing 1 is inserted at the position where the guide surface 8 is formed is φd ′> φD ₃ with respect to the inner diameter φd ′ of the bearing 2. .

[0006]

SUMMARY OF THE INVENTION As described above, the bearing 2
Because it does not go inside diameter .phi.d 'and the processing of the diameter [phi] D ₂ of the first guide surface 7 of the diameter [phi] D ₁ and the second guide surface 8 at the same time,
Diameter φD _{1 of} first guide surface 7 with respect to inner diameter φd ′ of bearing 2
In addition, the accuracy of the coaxiality of the diameter φD ₂ of the second guide surface 8 becomes insufficient, and each of the pair of suction ports 9 and discharge ports formed in the side plate 4 is point-symmetric with respect to the axis of the rotating shaft 3. The pressure balance was lost at each suction port and discharge port when the pump was operated, causing pulsation and vibration.

[0007]

SUMMARY OF THE INVENTION A vane pump according to the present invention has been made to solve the above-mentioned problem, and has a housing in which a guide surface having the same diameter and the same diameter as the inner periphery of a bearing for supporting a rotary shaft is formed in a housing. The contact surface provided on the side plate is guided by the guide surface to position the side plate.

[0008]

In the above, since the guide surface is coaxial and has the same diameter as the inner periphery of the bearing that supports the rotating shaft, the guide surface can be formed simultaneously with the inner periphery of the bearing. The precision can be the same as the processing precision of the inner circumference of the bearing. Accordingly, by guiding the contact surface of the side plate with the guide surface, the accuracy of the coaxiality of the side plate with respect to the rotation axis is improved.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 10 denotes a pump housing. The pump housing 10 is formed by abutting a front housing 11 and a rear housing 12, and a rotary shaft 20 is inserted into a shaft hole 13 provided in the front housing 11 through a bearing 14. Are rotatably mounted. The front housing 11 has a container shape with an abutting side open, and the front housing 11 is provided inside the front housing 11.
The side plate 21 is arranged in contact with the wall surface of the first side.

Here, a guide surface 15 having the same diameter as the inner diameter φd of the bearing 14 is formed on the front housing 11, while a protrusion 22 protruding toward the front housing is formed on the side plate 21. A contact surface 22 a having a diameter φd is formed in the portion 22, and the guide surface 15
This abutment surface 22a is guided. In addition, a cam ring 23 is arranged adjacent to the side plate 21,
The side plate 21 and the cam ring 23 are supported in the radial direction by a pin 31 pressed into the front housing 11. On the inner circumference of the cam ring 23,
A circular rotor 24 rotatably connected to the rotating shaft 20 is provided. The inner peripheral surface of the cam ring 23 is an elliptical cam surface 23a, and the tip of a vane 26 slidingly moving in a plurality of slits 25 formed on the outer periphery of the rotor 24 is in contact with the cam surface 23a. .

One end face of the rotor 24 and the cam ring 23 is in contact with the side face of the side plate 21, and the other end face is in contact with the wall surface of the rear housing 12, so that a closed pump chamber P is provided between the vanes 26. Are formed, and these pump chambers P repeatedly increase and decrease in volume as the rotor 24 rotates. And the side plate 2
A pair of suction ports 41 and discharge ports 51 and 52 are formed on the side surface of the pump housing P and the wall surface of the rear housing 12, respectively. Fluid is sucked into the pump chamber P sequentially from the suction port 41, and the pump chamber P gradually reduces in volume. The fluid is sequentially compressed and discharged to the discharge ports 51 and 52. Here, the discharge ports 51 and 52 are formed at point symmetric positions about the axis of the rotation shaft 20, and similarly, the suction ports 41 are respectively formed at point symmetric positions about the axis of the rotation shaft 20. ing.

A fluid supply port 42 is opened in the front housing 11, and a fluid flow space 43 communicating with the fluid supply port 42 is provided at a predetermined interval along the upper half circumferential surface of the cam ring 23 between the front housing 11 and the rear housing 12. The fluid flowing from the fluid supply port 42 through the fluid flow space 43 is supplied to the suction port 41.

The discharge ports 51, 52 on the front housing 11 side communicate with a pressure chamber 44 formed in the front housing 11, and the pressure chamber 44 is provided in a valve housing hole 16 formed in the front housing 11. The outflow flow rate of the fluid is controlled by the flow control device (not shown), and the fluid is sent to an operating device (not shown).

Here, in the above, the side plate 2
In order to ensure coaxiality with respect to the rotating shaft 20
The inner circumference of 4 and the guide surface 15 are processed as follows. First, a shaft hole 13 into which the outer peripheral surface of the bearing 14 is fitted to the front housing 11 from the left side in FIG.
Next, the bearing 14 is pressed into the shaft hole 13.

Next, the inner circumference of the bearing 14 and the guide surface 15 are simultaneously machined to the diameter φd of the rotating shaft 20. Here, the deformation at the inner and outer circumferences of the bearing 14 generated when the bearing 14 is press-fitted is absorbed, and the coaxiality of the inner circumference of the bearing 14 with respect to the rotating shaft 20 is ensured. Further, since the inner circumference of the bearing 14 and the guide surface 15 are processed in one pass, the processing time is also reduced. The side plate 21 is assembled to the front housing 11 processed as described above so that the contact surface 22 a of the contact portion 22 formed on the side plate 21 is guided by the guide surface 15 formed on the front housing 11. .

As described above, the coaxiality of the side plate 21 with respect to the rotation shaft 20 is ensured with respect to the guide surface 15. The coaxiality of the cam ring 23 with respect to the rotation shaft 20 is determined by the pin 31. Next, the operation in the above configuration will be described.

When the rotor 24 is driven to rotate by an external driving device, centrifugal force acts on each vane 26, and each vane 2
Numeral 6 protrudes from the inside of the slit 25, and its tip edge is rotated while sliding on the cam surface 23a on the inner periphery of the cam ring 23, and advances and retreats in the slit 25 radially along the shape of the cam surface 23a. . Then, the plurality of pump chambers P formed between the cam surface 23a and the outer peripheral surface of the rotor 24 and partitioned by the vanes 26 rotate by sequentially increasing and decreasing their respective volumes, and as a result, a pump action is performed. Hydraulic oil is sucked into the pump chamber P from the suction port 41, and is discharged from the discharge port 51,
Discharged from 52.

The pressure fluid discharged from the discharge ports 51 and 52 is sent to a flow control device (not shown) through a pressure chamber 44, and the flow control device controls the flow rate of the outflow fluid. Sent to In the above embodiment, the accuracy of the coaxiality of the side plate 21 with respect to the rotating shaft 20 is improved, so that the accuracy of the coaxiality of the cam ring 23 with respect to the rotating shaft 20 is improved. Pulsation and vibration occurring as a cause can be prevented, and the performance of the pump can be further improved.

[0019]

According to the vane pump of the present invention, a guide surface having the same diameter as the inner periphery of a bearing for supporting a rotary shaft is formed in a housing, and a contact surface provided on a side plate is guided by the guide surface. Since the side plate is positioned, the accuracy of the coaxiality of the side plate with respect to the rotating shaft can be improved, and a pair of discharge ports and suction ports formed on the side plate respectively align the axis of the rotating shaft. It is possible to prevent deviation from a point symmetrical position with respect to the center, to achieve a stable pressure balance at the discharge port and the suction port at the time of operation of the pump, to prevent pulsation and vibration, and to improve the performance of the pump. .

[Brief description of the drawings]

FIG. 1 is a sectional view of a vane pump showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is an enlarged sectional view of a main part of the embodiment of the present invention.

FIG. 4 is an enlarged sectional view of a main part of a conventional vane pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Housing 11 Front housing 12 Rear housing 13 Shaft hole 14 Bearing 15 Guide surface 20 Rotating shaft 21 Side plate 22 Projecting part 22a Contact surface 23 Cam ring 24 Rotor 25 Slit 26 Vane

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F04C 2/344 331

Claims (1)

(57) [Claims] 1. A housing, a rotating shaft rotatably supported by a bearing press-fitted into a shaft hole provided in the housing, a rotor housed in the housing and rotatably connected to the rotating shaft, A plurality of vanes slidably guided by slits formed in the rotor, a cam ring outside the rotor and in which the tip of the vane slides and is disposed between the cam ring and the housing. A vane pump having a side plate and a guide surface formed coaxially and with the same diameter as the inner periphery of the bearing in the housing, and a contact surface provided on the side plate is guided by the guide surface, and A vane pump characterized in that a plate is positioned.