JPH033076B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a power steering pump.

(Prior art) As shown in FIGS. 1 and 2, the casing 1
A thrust plate 3 and a pressure plate 4 are arranged on both sides of the cam ring 2 inside the cam ring 2, and a portion of high-pressure oil is supplied as lubricating oil to the gap 8 between the rotating shaft 6 of the rotor 5 and the bearing 7 inside the cam ring 2. Inflow, gap 8
A power steering pump is known in which the right end of the casing 1 is sealed with a seal member 10, and an oil drain passage 11 is communicated with the lower end of a vertical oil supply passage 12 in the upper part of the casing 1 from the back side of the seal member 10. However, since the oil drain path 11 passes above the high pressure chamber 9, a protrusion 13 is formed in the upper passage of the high pressure chamber 9, and the oil drain path 11 passes through this protrusion 13. Discharge port 1 of shear plate 4
High pressure oil from 4 flows into flow control valve chamber 1
This has the disadvantage that it disturbs the flow flowing into the tube 5, causing pulsation and noise. If this protrusion were to be eliminated, it would be necessary to increase the height of the entire casing, making the entire casing large, making it unsuitable for small cars and front-wheel drive cars. In addition, since the oil drain path must be formed between the high pressure chamber 9 and the flow control valve chamber 15, it is necessary to provide a long distance between the right end of the gap 8 and the vertical oil supply path, which requires the pump to be mounted on the shaft. This also contributed to the pump becoming larger.

(Purpose) The present invention was made by focusing on the fact that a low pressure section can be formed between the flow control valve chamber and the outer peripheral groove of the plunger. The purpose of this design is to eliminate the protrusions in the flow control valve, thereby making the entire structure more compact, and to prevent pulsation and noise from occurring in the high pressure chamber that flows into the flow control valve chamber.

(Example) FIGS. 3 to 5 show an example of the present invention.
21 is a casing which includes a cam ring 22, a thrust plate 23, a pressure plate 24, a rotor 25, a rotor rotation shaft 26, a bearing 27, a gap 28,
The seal member 30 and the vertical oil supply passage 32 are the same as those of the conventional product.

The present invention communicates the oil drain passage 31 of the gap 28 with the space 38 formed by the flow control valve chamber 35 and the outer circumferential groove 39 formed in the plunger 36, as shown in FIG. It is connected to the reflux port 37 of the flow control valve chamber 35 . 29 is a hyperbaric chamber.

(Effects) According to the present invention, a housing, a cam ring disposed inside the housing from one end side, a rotor disposed within the cam ring and having a plurality of vanes on the outer periphery, and a rotor sandwiching the cam ring from both sides. a thrust plate that closes one end of the housing, a pressure plate that is disposed deep inside the housing, a drive shaft that drives the rotor, and an oil supply path provided in the housing and to which a suction pipe is attached; a flow control valve chamber provided adjacent to the oil supply passage and communicated through a recirculation port; a plunger disposed in the flow control valve chamber for controlling the pump discharge flow rate; and a drive shaft at the other end of the housing. and a sealing member that maintains oil tightness with the sealing member, and an oil drainage passage that communicates the back side of the sealing member with the low pressure section communicates with a space formed by the flow control valve chamber and the outer circumferential groove of the plunger. Since the space is communicated with the reflux port of the flow control valve chamber, the protrusion that restricts the upper passage of the high pressure chamber can be made extremely small or eliminated, and the flow from the high pressure chamber to the flow control valve chamber can be made extremely small or eliminated. It does not disturb the flow in the high pressure chamber, prevents pulsation and noise, and eliminates the need for a drain passage between the high pressure chamber and the flow control valve chamber, reducing the axial length of the pump. In other words, the rotor rotation shaft and bearings can be shortened, so the whole can be made more compact, and it has the characteristics of being able to be installed in small cars and front-wheel drive cars.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view of the conventional product, Fig. 2 is a sectional view taken along line A-A in Fig. 1, Fig. 3 is a front sectional view of an embodiment of the present invention, and Fig. 4 is B in Fig. 3. -B side sectional view, 5th
The figure is an enlarged cross-sectional view of a main part of the flow control valve chamber shown in FIG. 4. 21...Casing, 25...Rotor, 26...
...Rotor rotating shaft, 27...Bearing, 28...Gap,
29... High pressure chamber, 31... Oil drain path, 35... Flow control valve chamber, 38... Portion of the flow control valve that always maintains low pressure.

Claims (1)

[Scope of Claims] 1. A housing, a cam ring disposed inside the housing from one end side, a rotor disposed within the cam ring and having a plurality of vanes on its outer periphery, and a housing sandwiching the cam ring from both sides. a thrust plate that closes one end; a pressure plate that is disposed deep inside the housing; a drive shaft that drives the rotor; an oil supply path provided in the housing and to which a suction pipe is attached; a flow control valve chamber provided adjacent to the oil supply passage and communicated through a return port; a plunger disposed in the flow control valve chamber for controlling the pump discharge flow rate; and a drive shaft at the other end of the housing. a sealing member that maintains oil-tightness, and an oil drain passage that communicates the back side of the sealing member with the low pressure section communicates with a space formed by the flow control valve chamber and the outer circumferential groove of the plunger. , A power steering pump in which the space is connected to a recirculation port of a flow control valve chamber.