JPH0329995B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vane pump, which is one type of rotary pump used in equipment such as superchargers and compressors.

[Conventional technology]

Conventionally, a vane pump whose schematic configuration is shown in FIG. 4 has been widely known.

In the figure, 31 is a housing, 32 is a rotor that is eccentrically inserted into the inner peripheral space of the housing 31 and rotatably supported by a rotating shaft 33, and 35a, 35b, and 35c are the outer periphery of the rotor 32. These are plate-shaped vanes that are disposed so as to be freely projectable and retractable in the radial direction in vane grooves 34a, 34b, and 34c that are equally spaced and recessed so as to divide the side into three parts in the circumferential direction. Rotating shaft 33
When the rotor 32 rotates in the direction of the arrow X in the figure, the vanes 35a, 35b, and 35c fly out in the outer radial direction due to centrifugal force, and rotate while their leading edges slide against the inner circumferential surface of the housing 31. As described above, since the rotor 32 is eccentric with respect to the housing 31, the housing 31, the rotor 32, and the vanes 35a, 35
Working spaces 36a and 36 divided by b and 35c
The volumes of b and 36c are expanded and contracted repeatedly, and the fluid sucked in from the suction port 37 is discharged from the discharge port 38.

[Problem that the invention seeks to solve]

However, in the conventional vane pump mentioned above, since the vanes slide at high speed on the inner circumferential surface of the housing, not only is it impossible to avoid the generation of high sliding heat and a significant decrease in volumetric efficiency due to sliding resistance, but also it is difficult to avoid wear. The progress is also significant, and there are problems such as the vane expanding due to heat generated by sliding and galling with both axially inner surfaces of the housing.

In view of these problems, the present invention has been made with the object of preventing sliding heat generation, wear, etc., and improving volumetric efficiency and durability.

[Means for solving problems]

That is, in the vane pump according to the present invention, the inner circumferential surface of the vane comes into contact with the protrusions provided at both axial ends of the vane in the circumferential groove formed inside both end walls of the housing, so that the vane does not come into contact with the inner circumferential surface of the housing. A journal bearing is rotatably mounted to hold the rotor in this state, and a small-diameter boss protruding coaxially with the inner circumferential surface of the housing that closely opposes the inner circumferential portion of both ends of the vane is provided on both end surfaces of the rotor. forming a circular recess that is coaxial with the outer peripheral surface and accommodates the boss;
The inner peripheral portions at both ends of the vane partition a space between the circular recess and the boss located at an eccentric position inside the circular recess into a plurality of chambers, and the circumferential groove extends through this space.

[Effect]

According to the present invention, the vane that pops out from the vane groove due to centrifugal force accompanying rotation is a journal bearing in which the protrusions at both ends are coaxial with the inner peripheral surface of the housing, in other words, eccentric with respect to the rotor. By coming into contact with the inner circumferential surface of the housing, movement in the radial direction is restricted, and the housing rotates without contacting the housing. In addition, the space between the circular recess on both end faces of the rotor and the boss located at an eccentric position inside the rotor is divided into multiple chambers by the inner periphery of both ends of the vane, which gradually shrinks and expands as the vane rotates. To repeat this, fluid constantly flows at high speed from the high-pressure side chamber in the compression process to the low-pressure side chamber in the expansion process via the circumferential groove in which the journal bearing is installed. Therefore, the dynamic pressure effect of the fluid acting on the journal bearing is extremely large, and the journal bearing rotates extremely smoothly in response to the torque caused by contact with the vane projection, so that the relative relationship between the bearing and the vane projection is Sliding can be kept small.

[Example] Hereinafter, an example of a vane pump according to the present invention will be described based on the drawings.

In Figures 1 to 3, 1 is a front housing, and 2 is a rear housing, both of which are lightweight and made of non-ferrous metals such as aluminum with a small coefficient of thermal expansion, and are integrally fixed to each other by bolts 3. There is. Reference numeral 4 denotes an iron rotor that is eccentrically inserted into the inner peripheral space 5 of the housing, and includes a ball bearing 7a that is located in the stepped portion of the shaft hole of the front housing 1 and is prevented from coming off by a fixing ring 6, and a rotor of the rear housing 2. A rotary shaft 1 is inserted into both housings 1 and 2 via a ball bearing 7b which is located in the stepped portion of the shaft hole and is prevented from coming off by a bearing cover 8, and the driving force is transmitted from the pulley 9.
It is pivoted to 0. 11a, 11b, and 11c are plate-shaped vanes mainly made of carbon material with excellent sliding properties, and vane grooves 12 are provided in the rotor 4 at equal intervals so as to divide the outer circumferential side of the rotor 4 into three parts in the circumferential direction.
a, 12b, and 12c, respectively, so as to be able to protrude and retract (slide) in the radial direction. Pins 13, 13 as protrusions are implanted at both axial ends of each vane 11a, 11b, 11c facing the inner surfaces of end walls 1', 2' of the front housing 1 and rear housing 2, respectively. and each pin 13,1
3 is fitted with a sleeve bearing (not shown) made of a resin material or the like having excellent sliding properties and wear resistance, if necessary. said housing both end walls 1',
A journal bearing 16 made of a lightweight material such as aluminum is installed in circumferential grooves 14a and 14b formed coaxially with the inner circumferential surface of the housing at 2'.
a, 16b are rotatably fitted loosely, and the circumferential surfaces (outer circumferential surfaces) and opposing side surfaces of the journal bearings 16a, 16b facing the circumferential grooves 14a, 14b are provided with grooves shown in FIGS. 3A and 3B. Dynamic pressure generating grooves 17 and 18 as illustrated are formed. Pin 1 of each vane 11a, 11b, 11c
3, 13 are the journal bearings 16a,
16b, and when rotated, the pins 13,
Each vane 11a, 11b, 11
c is restricted from moving in the radial direction, and rotates without contacting the inner circumferential surface of the housing. 15a, 15b are the vane grooves 12 of the vanes 11a, 11b, 11c when the pump is stopped.
a, 12b, 12c, and the vanes 11a, 11 at the time of starting the pump.
Pins 13 and 13 due to sudden protrusion of b and 11c
This is a small-diameter boss for avoiding excessive impact between the journal bearings 16a and 16b, and is formed to protrude concentrically with the circumferential grooves 14a and 14b.

Reference numerals 19a and 19b are circular recesses formed in both end faces of the rotor 4, and the recesses 19a and 19b and the bosses 15a and 15b eccentrically located inside the recesses 19a and 19b are arranged as shown by numerous dots in FIG. , crescent-shaped spaces 20A and 20B are formed.

The vane pump of this embodiment has the above configuration, and when the rotating shaft 10 and the rotor 4 rotate in the X direction by the driving force from the pulley 9, the vanes 11a, 1
1b and 11c are each pin 1 due to centrifugal force.
3 and 13 are journal bearings 16a and 16b
The front housing 1 and the rear housing 2 rotate in a non-contact state. Here, since the inner peripheral surface of the housing and the journal bearings 16a, 16b are in a coaxial relationship, and the journal bearings 16a, 16b and the rotor 4 are in an eccentric relationship, the vanes 11a, 1
1b and 11c are vane grooves 12a and 12 of the rotor 4
b and 12c are slid in the radial direction and repeatedly protruded and retracted, and both housings 1 and 2, the rotor 4 and the vane 11
Working space 5a divided by a, 11b, 11c,
The volumes of 5b and 5c are repeatedly increased and decreased. That is,
In FIG. 2, the volume of the working space 5a expands as it rotates and sucks in fluid from a suction port (not shown) that opens into the section, and the volume of the working space 5c contracts as it rotates and opens into the section. This shows a process in which fluid is discharged to a discharge port (not shown) and the fluid sucked into the working space 5b is transferred toward the discharge port.

In the above operation, the vanes 11a, 11b, 1
1c does not come into sliding contact with the front housing 1 and the rear housing 2 at all as mentioned above,
Further, the pins 13, 13 integrated with the vanes 11a, 11b, 11c are journal bearings 16a,
It rotates while being pressed against the inner circumferential surface of the journal bearing 16b, thereby applying rotational torque to the journal bearings 16a and 16b. On the other hand, the inner peripheral portions 111, 112 at both ends of the vanes 11a, 11b, 11c have circular recesses 19a, 1
Spaces 20A, 20 between 9b and bosses 15a, 15b
B is divided into chambers 201, 202, and 203, respectively, and each chamber 201, 202, and 203 repeatedly contracts and expands as the vanes 11a, 11b, and 11c rotate. Therefore, the fluid in the chamber 201 during the compression process flows through the journal bearings 16a, 16b.
flows at high speed to the chamber 203 in the expansion process via the circumferential grooves 14a and 14b into which the circumferential groove 14 is fitted.
a, 14b and journal bearings 16a, 16
A significant dynamic pressure that acts as a bearing force is generated between the dynamic pressure generating grooves 17 and 18 of b, and the journal bearings 16a and 16b are almost in a no-load state. It rotates extremely smoothly, and the amount of sliding with respect to the pin 13 is kept to a minimum.

Note that because the rotor is eccentric, the relative angle between the vanes and the inner circumferential surface of the housing changes repeatedly as it rotates. The locus of the edge becomes an approximate ellipse. Therefore, it is desirable that the inner circumferential surface of the housing is also formed in a shape corresponding to the locus so that the clearance between the vane tip edge and the inner circumferential surface of the housing is always kept constant.

〔Effect of the invention〕

As explained above, in the vane pump according to the present invention, the protrusions provided at both ends of the vane contact the inner circumferential surface of the journal bearing provided coaxially and rotatably with the inner circumferential surface of the housing, so that the vane is rotated. Since it is configured to restrict radial movement so that it rotates without contacting the housing, it minimizes the decline in pump efficiency and progression of wear due to sliding resistance and high sliding heat generation. It is possible to reduce the temperature of the fluid discharged from the pump, and the pump action from the space formed between the circular recess of the rotor and the boss of the housing allows the journal bearing to reduce the temperature caused by dynamic pressure. Since a remarkable bearing force is obtained and the rotor rotates under almost no load, the sliding resistance between the journal bearing and the vane protrusion can be extremely reduced, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the first embodiment of the vane pump of the present invention, FIG.
This figure is also a perspective view of the main parts, and FIG. 4 is a front sectional view showing the schematic structure of a conventional vane pump. 1...Front housing, 1', 2'...End wall, 2...Rear housing, 4...Rotor, 10
... Rotating shaft, 11a, 11b, 11c ... Vane, 12a, 12b, 12c ... Vane groove, 13
...Pins as protrusions, 16a, 16b...Journal bearings, 19a, 19b...Ball bearings.

Claims (1)

[Claims] 1. It has a rotor eccentrically and rotatably supported in the inner circumferential space of the housing, and a plate-shaped vane that is disposed so as to be freely projectable and retractable into a plurality of vane grooves recessed in the rotor, In a structure in which fluid is sucked in from one side and discharged to the other by utilizing repeated volume changes of the working space between each vane as the rotor and vanes rotate, a circumferential groove formed on the inside of both end walls of the housing has a A journal bearing is rotatably provided, the inner circumferential surface of which comes into contact with protrusions provided at both ends of the vane in the axial direction to hold the vane in a non-contact state with the inner circumferential surface of the housing, and is also provided with a journal bearing that is in close proximity to the inner circumferential portion of both ends of the vane. Opposing small-diameter bosses protrude coaxially with the inner circumferential surface of the housing, and circular recesses coaxial with the outer circumferential surface of the rotor and into which the bosses are loosely fitted are formed on both end surfaces of the rotor. , the inner peripheral portions at both ends of the vane partition a space between the circular recess and the boss located at an eccentric position inside the circular recess into a plurality of chambers, and the circumferential groove extends through this space. vane pump.