JPS6179881A - Vane pump - Google Patents

Abstract

PURPOSE:To eliminate the shortage of pressure increase by dividing the back- pressure groove between the discharge divisions by a vane pump into plural parts and forming the vane chamber sealed divisions between the divisions. CONSTITUTION:The back-pressure groove 17 on the discharge side of a vane pump is divided into plural parts, and the divisions 20 in which the amount Q of oil pushed-out by a vane 17 forms the sealed division 19 of a vane chamber 6 between the divisions of the back-pressure groove 17. Therefore, the liquid pressure discharge into a hollow chamber 14 is introduced into the vane chamber 6 from the back-pressure grooves 15 and 17, and the back-pressure action for pushing the vane 7 onto a cam ring 3 is executed. Therefore, the back-pressure force is increased by compressing the oil left in the sealed division 19 of the vane chamber 19 between the divisions of the back-pressure groove 17, and the shortage of pressure can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a vane pump that sucks in and discharges liquid such as oil.

<Prior art> A rotor that rotates inside a cam ring is provided with vane chambers radially, and has vanes that slide in the radial direction within the vane chambers.As the rotor rotates, the volume of each pump chamber divided between the vanes increases. Vane pumps are well known which increase and decrease the volume of fluid, suck in liquid from a suction boat, and discharge it from a discharge port.

By the way, in the suction section and the discharge section, the vane is pushed in the backward direction by the hydraulic pressure acting on the vane, creating a gap at the tip of the vane that makes sliding contact with the cam ring, causing a problem in which the liquid in the pump chamber leaks. .

In order to solve this problem, a back pressure groove that guides a part of the discharge pressure to the vane chamber at the back of the vane is provided in the suction and discharge sections, and a back pressure groove on the discharge section side where the pressure is higher than the suction side is For example, a vane pump that has a throttle hole in the ninth corner to increase back pressure, applies back pressure to the liquid discharged from the vane chamber when the vane retreats, and forcibly presses the tip of the vane against the cam ring to ensure a sealing function is disclosed in the U.S. patent. 3rd degree 2nd ('17,
No. 077.

<Problems to be Solved by the Invention> In the case of the above-mentioned conventional vane pump, the number of vane chambers communicating with one discharge side back pressure groove varies from 2 to 3, and the combined discharge amount also varies as shown in the lower graph of Figure 4. It fluctuates. In a region 20 where the amount of oil pushed out by the rear end of the vane into the back pressure groove decreases due to this fluctuation, the vane tip becomes separated from the cam ring, causing a problem in which pulsation or imaging occurs.

The present invention solves the above conventional problems by preventing insufficient pressure rise even when the amount of oil pushed out by the vane decreases.
A vane pump is provided.

Means for Solving the Problems> The present invention divides the back pressure groove of the discharge section having a throttle hole into a plurality of parts, and is located between the divisions to cope with the problem in which the amount of oil discharged from the vane chamber decreases. This forms a sealed section of the vane chamber.

Function> The above-mentioned present invention provides a vane chamber sealed section even in a region where the amount of oil pushed out by the vane decreases, so the pressure inside the vane chamber increases, and the vane tip is reliably pressed against the cam ring to maintain the sealing function. .

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings. Referring to FIGS. 1 and 2, 1 is a pump housing, the opening at one end of which is covered by an end cover 2. As shown in FIGS. A cam ring 3 is fixedly installed inside the pump housing 1, and a rotor 5 rotated by a rotating shaft 4 is installed inside the cam ring 3. This rotor 5 is provided with vane chambers 6 radially, into which vanes 7 are fitted so as to be slidable in the radial direction.

A side plate 8 is arranged on the 11th surface of the cam ring 3 and the rotor 5 on the rotating shaft 4 side, and a pressure plate 9 is arranged on the side surface on the end cover 2 side. It is pressed against the cam ring 3 and the rotor 5 by a nup ring 10 interposed therebetween.

-4 ((, pressure plate 9 and end cover 2
A hollow chamber 14 is formed between the two.

Further, an annular groove 11 serving as a suction passage is formed between the outer periphery of the cam ring 3 and the pump housing 1, and a pump chamber is defined between the annular groove 11 and the vane 1 in the side plate 8 and the pressure plate 9. Communication with 1-
A suction port 12 is provided.

Also, is there a pump chamber and flow rate on side plate 8? filf
The pressure plate 9 is provided with a discharge port h 13 a that communicates with both valves 18 , and a discharge port 13 b that communicates between the pump chamber and the hollow chamber 14 .

Furthermore, the pressure plate 9 has vanes 7 in the suction section.
a back pressure groove 15 on the suction side in which the vane chamber 6 and the hollow chamber 14 in the retreating section communicate with each other;
A back pressure groove 17 on the discharge side is provided, which communicates with the back pressure groove 17 on the discharge side.

The present invention reduces the back pressure 13I17 on the discharge side by dividing the back pressure groove 17 into a plurality of parts in the discharge section, as shown in the developed view of FIG. A sealed section 19 of the vane chamber 6 is formed between the divisions of the back pressure groove 17. Note that 21 in FIG. 4 indicates the cam lift of the cam ring 3.

Since the present invention has the structure as described above, the discharge port 13
The liquid pressure discharged from b into the hollow chamber 14 is the back pressure @15.1
7 into the vane chamber 6, and the vane 7 is connected to the cam ring 3.
Provides a back pressure effect to press against. Particularly on the discharge side where the pressure inside the pump chamber increases, a back pressure higher than that on the suction side is applied by the throttle hole 16 to ensure a seal.

By the way, in the conventional back pressure groove that is continuous over the entire discharge section, the amount of oil pushed into the back pressure groove decreases due to the retreat of the vane 7 by the cam lift 21, and the back pressure to press the vane 7 is insufficient, but in the present invention. The amount of oil remaining in the sealed section 19 of the vane chamber between the divisions of the back pressure groove 17 is compressed to increase the back pressure and secure the pressing force of the vane 7.

By setting the interval between the sealed sections 19 to be large or small, the pressure increase can be adjusted in size.

<Effects of the Invention> As described above, according to the present invention, the back pressure groove in the discharge section where the amount of oil pushed out by the vane is small is eliminated, and a vane chamber sealed section is formed. The increase in the pressure of the oil amount ensures sufficient back pressure to press the vane, which maintains a pressure seal with the cam ring and has the effect of preventing pulsation and imaging.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the present invention, Fig. 2 is a sectional view taken along the line 1-1 in Fig. 1, Fig. 3 is a sectional view taken along the line @ Fig. In the exploded view, 1... pump housing, 3. e. cam ring, 4.
... Rotating shaft, 5... Rotor, 6... Vane chamber, 7.
...Vane, 12---Suction boat, 13a, 13b-
@e discharge boat, 14... hollow base, 15.17...
Back pressure groove, 16-... Throttle hole, 19... Sealed section. Patent applicant: Toyoda Machine Machinery Co., Ltd. Agent: Hirai Nibu■1

Claims (1)

[Claims] It has a cam ring, a rotor that rotates inside the cam ring, and vanes that slide in the radial direction within vane chambers provided radially on the rotor. As the rotor rotates, the volume of each pump chamber divided between the vanes increases or decreases. A back pressure groove is provided in the suction and discharge sections to conduct a part of the discharge pressure to the vane chamber at the back of the vane in order to press and seal the vane in the cam ring direction, and a throttle hole is provided in the back pressure groove in the discharge section. A vane pump comprising: a back pressure groove in the discharge section is divided into a plurality of sections, and a vane chamber sealed section is formed between the sections.