JPH0552438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in vane pumps used as power sources for vehicle power steering systems and the like.

First, a conventional vane pump will be explained with reference to FIGS. 1 to 3. In the figure, reference numeral 1 denotes a housing that rotatably supports a drive shaft 4 through bearings 2 and 3. This housing 1 is formed with an annular recess 5 that is open at one end. A cam ring 7 that accommodates a rotor 6 splined to the drive shaft is disposed therein. A plurality of vanes 8...8 are attached to the rotor 6 so as to be freely protruding and retracting in substantially radial directions, and the tips of these vanes 8...8 are attached to the cam ring 7.
The working chambers 9...9 are formed between adjacent vanes by slidingly contacting the inner circumferential cam surface 7a of the vanes. The volume of the working chamber 9 changes as the rotor 6 rotates, and two suction sections where the volume increases and two compression sections where the volume decreases are formed.

Reference numeral 10 denotes a side plate, which is disposed in contact with one side of the cam ring 7 in an annular recess 5 of the housing 1, and forms a high pressure chamber 11 for discharge oil in the annular recess 5. There is. This side plate 10 is provided with a discharge port 12 recessed facing the discharge section of the working chamber 9 and a discharge passage 13 connected to the discharge port 12. is guided to the high pressure chamber 11, and therefore, the side plate 10 is pressed against the cam ring 7 by the discharge pressure in the high pressure chamber 11 and the spring force of the spring 14 tensioned in the high pressure chamber 11. ,
The interior of the work chamber 9 is kept oil-tight. In addition, a plurality of through holes 15 are bored in this side plate 10, and communicate the annular groove 16 which is not continuous in the circumferential direction formed on the sliding surface with the rotor 6 and the high pressure chamber 11, Through these through holes 15 and annular groove 16, a part of the discharged oil in the high pressure chamber 11 is guided to the base end of a plurality of vane slots 8a formed in the rotor 6, and is guided in a radial direction with respect to the vanes 8...8. It has come to give the power of. Note that 17 and 18 are seal rings for sealing the high pressure chamber 11.

19 is a flow control valve, and this flow control valve 19 is
It is provided between a high-pressure passage 20 led from the high-pressure chamber 11 and a low-pressure passage 22 connected to the suction hole 21, and the excess oil of the discharged oil collected in the high-pressure chamber 11 is transferred to the low-pressure passage 22. The discharge amount discharged from the discharge hole 23 is controlled to be constant.

A cover plate 24 is attached to the housing 1 by bolts (not shown) and closes the open end of the housing 1. The cover plate 24 includes a suction passage 25 connected to the low pressure passage 22, and a suction passage 25 connected to the low pressure passage 22. A branch passage 27 is formed that branches from the suction passage 25 and communicates with a suction port 26 that opens facing the suction section of the working chamber 9.
A portion of the suction port 26 is connected to the cam ring 7.
By opening into a side passage 28 formed in the side plate and communicating with a suction port (not shown) formed as a recess in the side plate 10 through this side passage 28, a left and right side can be opened in the working chamber 9. It is now possible to inhale at the same time from the beginning to increase inhalation efficiency. Further, in the sliding contact surface of the cover plate 24 with the rotor 6, a discharge port 29 and an annular groove 30 which is not continuous in the circumferential direction are formed as depressions, similarly to the side plate 10. The outer circumferential shape of the cover plate 24 is approximately the same as that of the housing 1 at the joint with the housing 1.

At the joint between the housing 1 and the cover plate 24, there is an annular recess 5 of the housing 1 and a low pressure passage 22.
A seal ring 31 surrounding the housing 1 is provided, and the seal ring 31 is housed in a seal groove 32 formed in the housing 1 to prevent leakage of hydraulic oil.

Note that 33 is a shaft seal that seals between the housing 1 and the drive shaft 4, and 34 is a pulley spline-coupled to the drive shaft 4.

In such a configuration, by rotating the rotor 6 via the pulley 34 and the drive shaft 4 by an engine or the like, hydraulic oil stored in a reservoir (not shown) is transferred to the suction hole 21, the low pressure passage 22, the suction passage 25,
The oil is introduced into the working chamber 9 through the branch passage 27 and the suction port 26, and then the sucked oil is transferred to the discharge ports 12, 29, the high pressure chamber 11, and the flow control valve 1.
9 and is discharged from the discharge hole 23.

By the way, in such a conventional vane pump, a seal ring 31 housed in a seal groove 32 connects the joint between the housing 1 and the cover plate 24.
Since the structure is configured to seal with It is necessary to process and assemble the seal ring 31 with due care, and there is also a drawback that it is not possible to visually check whether the seal ring 31 is correctly assembled after assembly.

Therefore, this invention makes it possible to eliminate the need for machining a seal groove by sandwiching a seal plate with a seal ring adhered to the inner circumferential side at the joint between the housing and the cover plate. The purpose is to obtain a vane pump that allows checking the correct assembly by appearance.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same reference numerals are attached to the same components as in the prior art, and redundant explanation will be omitted.

FIGS. 4 and 5 are drawings showing an embodiment of the present invention. That is, a seal plate 35 is sandwiched between the housing 1 and the cover plate 24. This sealing plate 35 is made of a thin plate 36, preferably a thin steel plate.

As shown in FIG. 6, the outer circumferential shape of the thin plate 36 is made to be approximately the same as the outer circumferential shape of the joint between the housing 1 and the cover plate 24, and
The inner peripheral shape of the thin plate 36 surrounds the annular recess 5 of the housing 1 and the low pressure passage 22 provided outside the annular recess 5 when the outer peripheral shape is matched to the outer peripheral shapes of the housing 1 and the cover plate 24. It is formed into a non-circular shape, and a rubber seal ring 37 is vulcanized and bonded along the inner peripheral surface of this non-circular shape.

The thin plate 36 also has bolt holes 38 provided at the four corners of the housing 1 and the cover plate 24 when its outer circumference is matched to the outer circumference of the joint between the housing 1 and the cover plate 24.
...38 and 39...39 are provided with bolt insertion holes 40...40 that match the positions. Further, the width dimension W of the seal ring 36 is formed to be slightly larger than the thickness t of the thin plate 36, as shown in FIG. It is sandwiched between the two and can achieve a sufficient sealing effect.

With this configuration, the seam between the housing 1 and the cover plate 24 can be sealed with the seal plate 35 without providing a seal groove.
Furthermore, after assembling the vane pump, it is possible to check whether the seal plate 35 has been correctly assembled by observing the external appearance. Even if the seal plate 35 is installed, it is possible to prevent it from accidentally being shipped from the production line, and the assembly of the seal plate 35 is
Since the work is completed simply by inserting it into the seam between the housing 1 and the cover plate 24, the assembly work is also facilitated.

As explained above, according to the present invention, by inserting the seal plate at the joint between the housing and the cover plate, it is possible to seal the joint between the housing and the cover plate without the need for seal groove processing, etc. can. In addition, by forming the outer circumferential shape of the seal plate to be approximately the same as the outer circumferential shape of the joint between the housing and the cover plate, the seal plate can be provided without damaging the appearance of the pump, and the seal can be sealed after assembly. It is possible to visually check whether the plates are correctly assembled. Furthermore, by providing a seal ring on the inner periphery of the seal plate that surrounds the annular recess of the housing and the low pressure passage provided on the outer periphery of the annular recess, when the outer periphery shape is matched to the outer periphery shape of the housing, etc., the cam ring Since the high pressure oil leaking from between the pump and the cover plate flows into the low pressure passage, the seal plate is essentially kept in a low pressure state, and the seal plate only needs to seal the low pressure without directly receiving the high pressure of the pump. Therefore, it has excellent sealing performance and durability. Furthermore, on the seal plate,
When its outer circumferential shape is matched to that of the housing and cover plate, the seal plate can be centered and stopped from rotating by providing bolt insertion holes that match the bolt holes provided in the housing and cover plate. . Therefore, a vane pump with excellent durability and reliability can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional vane pump, FIG. 2 is a cross-sectional view taken along the line -- in FIG. 1, FIG. 3 is a cross-sectional view taken along the line -- in FIG. 5 is a cross-sectional view taken along the line -- in FIG. 4, FIG. 6 is a front view of the seal plate, and FIG. 7 is a cross-sectional view taken along the line -- in FIG. 6. DESCRIPTION OF SYMBOLS 1... Housing, 4... Drive shaft, 5... Annular recess, 6... Rotor, 7... Cam ring, 8... Vane, 9... Working chamber, 10... Side plate, 1
1... Hyperbaric chamber, 24... Cover plate, 35...
... Seal plate, 38 ... Bolt holes provided in the housing, 39 ... Bolt holes provided in the cover plate, 40 ... Bolt insertion holes provided in the seal plate.

Claims (1)

[Claims] 1. A housing in which an annular recess with an open end is formed, a cam ring that accommodates a rotor that is housed in the annular recess of the housing and has a plurality of vanes attached thereto so as to be freely retractable in substantially radial directions; In the vane pump, the vane pump includes a side plate that is in contact with the housing and forms a high-pressure chamber for discharged oil in an annular recess of the housing, and a cover plate that closes an open end of the housing, and a seal plate is sandwiched between the housing and the cover plate. The outer periphery of the seal plate is formed to be approximately the same as the outer periphery of the joint between the housing and the cover plate, and the outer periphery of the seal plate is formed to match the outer periphery of the housing, etc. Sometimes, a seal ring is provided to surround the annular recess of the housing and the low pressure passage provided on the outer periphery of the annular recess, and the seal plate is further provided with a seal ring whose outer periphery shape is matched to the outer periphery shape of the housing and the cover plate. A vane pump characterized in that bolt insertion holes are provided that match the bolt holes provided in the housing and the cover plate.