JP6886314B2 - Vane pump - Google Patents

Description

The present invention relates to a vane pump whose working fluid is an incompressible fluid such as a liquid.

Various vane pumps have been conventionally proposed in which the cam ring and the rotor are eccentric and the vanes (blades) move freely in the radial groove processed in the rotor (see, for example, Patent Document 1).
Vane pump is a useful technology, but when the working fluid is a liquid, the liquid does not have compressibility or expansion, so it is necessary to devise a port shape so that so-called "confinement" or cavitation does not occur. There is a problem.
Hereinafter, problems in the conventional vane pump will be described with reference to FIG.

In FIG. 8, in the conventional vane pump whose whole is indicated by reference numeral 100, it has a cam ring 101 and a rotor 102 whose center is eccentric (the inner diameter of the cam ring is indicated by reference numeral δ in FIG. 8). There is. Although not shown, the rotor 102 is formed with a plurality of vane grooves (not shown) extending in the radial direction, and vanes (not shown) are inserted into the vane grooves. The vane (not shown) is configured to be movable in the radial direction along the vane groove.
In FIG. 8, vanes and vane grooves (not shown) are provided along the virtual lines L1 to L6 extending outward in the radial direction from the rotor rotation center O1 in the rotor 102. Then, the vane is urged outward in the radial direction and protrudes by performing pressure loading on the vane groove, and the radial outer end portion of the vane slides on the inner peripheral surface of the cam ring 101.

In FIG. 8 showing the relative positions of the cam ring 101 and the rotor 102 at a certain moment, the space α (gap, pump chamber) defined by the vane (unsigned) indicated by the virtual line L1 and the vane (unsigned) indicated by the virtual line L2. Is a gap between the rotor 102 and the cam ring 101, which is a pump chamber. At the moment shown in FIG. 8, the gap α, which is the pump chamber, does not communicate with the inlet port 101A and does not communicate with the outlet port 101B.
When the rotor 102 rotates (in the direction of arrow R1) in such a state (not communicating with the inlet port 101A and not communicating with the outlet port 101B), the gap α is not supplied with liquid (working fluid). It will expand, and a space (cavity) in which no liquid exists will be created in the gap α.
When the rotor 102 further rotates toward the arrow R1 side in the state where the cavity is generated, the gap α contracts as the space α moves toward the outlet port 101B side, and the pressure of the gap α increases. Crush. Then, when the cavity is suddenly crushed, a large noise is generated.

Here, the position of the inlet port can be adjusted so that the gap α does not expand further from the moment when the gap α does not communicate with the inlet port.
However, in that case, since the rotor rotates and the gap α contracts as the gap α moves toward the outlet port side, the gap α contracts until the gap α communicates with the outlet port, but the liquid in the gap α Continues to be unexhausted and the pressure rises sharply. As a result, a so-called "confinement" phenomenon is caused, and noise is also generated.

In order to prevent such noise, although not shown in patent documents and the like, when the working fluid is an incompressible liquid, in the prior art, the region between the inlet port and the outlet port (FIG. 8). Then, a port was formed in the region between the virtual line L1 and the virtual line L3) to prevent the pressure from rising in the gap space α and prevent the generation of noise.
However, forming such a port (a port formed in the region between the virtual line L1 and the virtual line L3, which is not shown in FIG. 8) separately from the inlet port and the outlet port is used in cam ring manufacturing and port manufacturing. Increase labor and cost.
Further, in the prior art, a port separately formed in the region between the inlet port and the outlet port is processed into a complicated shape, and the pump discharge pressure is applied to the vane groove formed along the virtual lines L1 to L6. Introduce and perform pressure loading. However, such complicated processing further increases the labor and cost for manufacturing.

Japanese Unexamined Patent Publication No. 2012-163040

The present invention has been proposed in view of the above-mentioned problems of the prior art, and it is possible to prevent the generation of noise even when the working fluid is incompressible, and to reduce the labor and cost for manufacturing. The purpose is to provide a vane pump that can be used.

In the vane pump (10) of the present invention, from the cam ring (1), the rotor (2) whose rotation center is eccentric (δ1) with respect to the inner diameter center of the cam ring (1), and the rotation center of the rotor (2). In a vane pump (10) having a vane groove (2A) formed outward in the radial direction and a vane (3: blade) movable in the vane groove (2A).
The working fluid is incompressible (eg, liquids such as water and coolant) and
The cam ring (1) is provided with an inlet port (1A) and an exit port (1B).
The inlet port (1A) and the outlet port (1B) are formed at positions symmetrical with respect to the center of the inner diameter of the cam ring (1), and are defined by adjacent vanes (3), rotors (2), and cam rings (1). Either the inlet port (1A) or the outlet port (1B) is applicable except for the moment when the volume of the gap region (α1: the gap between the rotor 2 and the cam ring 1: the pump chamber) to be partitioned) is maximized. It is formed at a position communicating with the gap region (α1), and no auxiliary port is formed in the region between the inlet port (1A) and the outlet port (1B) of the cam ring (1), and the inside of the cam ring (1). A communication groove (1D) is formed at a position corresponding to the gap region (α1: pump chamber) on the peripheral surface where the volume is maximized.
It has side plates (4, 5) that cover the open ends (upper and lower ends of FIG. 7) of the cam ring (1).
The outlet port (1B) of the cam ring (1) is formed with a through hole (1C) communicating with one of the side plates (4, 5) (for example, the upper side plate 4 in FIG. 7).
On the side plate (4) on the side where the through hole (1C) communicates (upper in FIG. 7), a path (4A) extending inward in the radial direction from the place where the through hole (1C) communicates is formed. And
The radial inner end (2AA) of the vane groove (2A) of the rotor (2) communicates with the annular groove (4B) formed in the side plate (4), and the annular groove (4B) is communicated with the annular groove (4B). ) Is communicating with the path (4A) formed on the side plate (4).
Here, the phrase "center of the inner diameter of the cam ring (1)" means "center of curvature of the inner peripheral surface of the cam ring (1)".

In the present invention, the drive source is not particularly limited to electric motors such as DC motors and AC motors, internal combustion engines, output shafts of transmissions, and the like.

According to the present invention having the above-described configuration, the volume of the gap region (α1: see FIG. 4: pump chamber) defined (partitioned) by the adjacent vane (3), rotor (2) and cam ring (1) is Since either the inlet port (1A) or the exit port (1B) is formed at a position communicating with the gap region (α1) except for the moment when the maximum is reached, the gap region (α1: see FIG. 4) is expanded. It always communicates with the inlet port (1A), and when the gap region (α1) contracts, it always communicates with the outlet port (1B).
Therefore, when the gap region (α1) expands, the liquid (working fluid) is supplied from the inlet port (1A), so that no cavity is generated, and noise generation due to the collapse of the cavity is prevented.
Further, when the gap region (α1) contracts, the liquid is discharged from the outlet port (1B), so that the pressure of the liquid does not rise (rapidly), and a so-called “confinement” phenomenon occurs. Is prevented, and the generation of noise is also prevented.

Therefore, noise is prevented from being generated even if an auxiliary port is not formed in the area between the inlet port (1A) and the outlet port (1B) of the cam ring (1), and complicated processing is performed on the cam ring (1) and the pump body. No need to apply.
Further, the inlet port (1A) and the outlet port (1B) are arranged so as to be point-symmetrical with respect to the center of the inner diameter of the cam ring (1) and are arranged in the radial direction. There is no need to form (elbow) or curved parts. Therefore, the resistance of the flow path is reduced and the efficiency is improved.

Here, when the gap region (α1: pump chamber) communicates with the inlet port (1A) (state before the moment when the volume of the gap region α1 becomes maximum), the gap region is passed through the inlet port (1A). The flow velocity of the working fluid flowing into (α1) is very fast (so-called “vigorous” inflow), the pressure of the working fluid decreases by the amount of the high flow velocity, and the pressure in the gap region (α1) becomes the outlet port (1B). There are cases where the pressure is much lower than the increased pressure on the) side.
In such a case, immediately after the gap region (α1: pump chamber) communicates with the outlet port (1B) (state in FIG. 5), the pressure of the high-pressure working fluid existing in the outlet port (1B) is applied to the gap region (1B). It acts on (α1: pump chamber), and the pressure in the gap region (α1) rises sharply, causing noise.
Further, as the pressure of the working fluid in the gap region (α1) rises, the increased pressure acts on the radial outer end of the vane (3), and the vane (3) is pushed back inward in the radial direction. , The working fluid (liquid) may leak to the adjacent gap region (for example, the gap region α02 shown in FIG. 5).
On the other hand, according to the present invention, the communication groove (1D) is formed at a position corresponding to the gap region (α1) on the inner peripheral surface of the cam ring (1) where the volume is maximized. Even if the pressure in the gap region (α1) rises sharply (or for the purpose of avoiding the sudden pressure increase), the gap region (α1) is passed through the communication groove (1D). Pressure can be released to the inlet port (1A) side. Therefore, the pressure in the gap region (α1) does not rise excessively, and noise is not generated. Further, since the pressure in the gap region (α1) is prevented from rising excessively, the vane (3) is not pushed back inward in the radial direction.

Then, in the present invention, the side plate (4, 5) covering the open end portion (upper and lower end portions in FIG. 7) of the cam ring (1) is provided, and the side plate (4,) is connected to the outlet port (1B) of the cam ring (1). A through hole (1C) communicating with either one of 5) (for example, the upper side plate 4 in FIG. 7) is formed, and the side on the side (upper in FIG. 7) with which the through hole (1C) communicates. A path (4A) is formed in the plate (4) from the point where the through hole (1C) communicates inward in the radial direction, and the vane groove (2A) of the rotor (2) has an inward radial end (2AA). An outlet port can be obtained by communicating with the annular groove (4B) formed in the side plate (4) and communicating the annular groove (4B) with the path (4A) formed in the side plate (4). Pressure loading can be performed by introducing the boosted working fluid (liquid) flowing through (1B) into the radial inner end (2AA) of the vane groove (2A) of the rotor (2).
At that time, it is not necessary to form a port (auxiliary port) in the area between the inlet port (1A) and the exit port (1B) of the cam ring (1), and it is not necessary to perform complicated processing on the auxiliary port. , The production of the cam ring (1) becomes easier, and the labor and cost for production can be further reduced.

It is sectional drawing which shows the embodiment of this invention. It is a cross-sectional view taken along the arrow A2-A2 of FIG. It is explanatory drawing which shows the cam ring and the rotor in FIG. It is explanatory drawing which shows typically the relative position of the cam ring and a rotor shown in FIG. It is explanatory drawing which shows the action of the communication groove on the inner peripheral surface of a cam ring. It is explanatory drawing which shows the relationship between the cross-sectional shape of the communication groove of FIG. 5 and the flow velocity distribution of a working fluid in a gap region (pump chamber). It is explanatory drawing of A5 arrow view of FIG. It is a top sectional view which shows the conventional vane pump.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. First, the vane pump according to the embodiment will be described with reference to FIGS. 1 and 2.
In FIG. 1, the vane pump 10 has a cam ring 1 and a rotor 2, and the rotor 2 is rotationally driven by a rotating shaft of an electric motor 20. Then, in FIG. 1, the vane pump 10 and the electric motor 20 are integrally configured.
The electric motor 20 includes a motor shaft 23, a motor rotor 24, and a motor stator 25. The motor shaft 23 is rotatably supported by the motor housing 22 via bushes 21A and 21B, and the bush 21B is provided in the pump case 6 of the vane pump 10. The motor rotor 24 has a plurality of permanent magnets arranged in the circumferential direction and is fixed to the motor shaft 23. The motor stator 25 is fixed to the inner circumference of the motor housing 22, and a coil (not shown) is wound around the motor stator 25.
Here, the drive source is not limited to the electric motor 20, and various sources such as an internal combustion engine, an output shaft of a transmission, and the like can be applied, and the drive source is not particularly limited.
The motor rotor 24 and the motor stator 25 are arranged concentrically, and there is a slight gap between the motor rotor 24 and the motor stator 25.
In FIG. 1, reference numeral 26 indicates a stator core, reference numerals 27A and 27B indicate thrust washers, and reference numeral 28 indicates a frame.

The motor shaft 23 extends inside the pump case 6 of the vane pump 10, and the vane pump 10 side end (right end in FIG. 1) of the motor shaft 23 is rotatably supported by the bush 21C. The bush 21C is provided on the pump cover 7 of the vane pump 10, and the pump cover 7 is provided so as to cover the opening (right end in FIG. 1) of the pump case 6.
The rotor 2 of the vane pump 10 is connected to the motor shaft 23 by the connecting means 23A (fixed key). A plurality of vane grooves 2A (FIG. 2) are formed from the center of the rotor 2 in the radial direction toward the outside in the radial direction, and vanes 3 (blades) that can move in the radial direction are provided in the vane grooves 2A. There is. The cam ring 1 of the vane pump 10 accommodates the rotor 2, and the tip portion of the vane 3 is in sliding contact with the inner peripheral surface (cam surface) of the cam ring 1 as the rotor 2 rotates.
Amount of eccentricity between the center of rotation of the roughly cylindrical rotor 2 and the center of the inner diameter of the cam ring 1 having an inner peripheral surface (cam surface) larger than the outer diameter of the rotor 2 (center of curvature of the inner peripheral surface of the cam ring 1). Is indicated by reference numeral δ1 in FIG. In other words, in FIGS. 2 and 4, the center of rotation of the rotor 2 and the center of the inner diameter of the cam ring 1 are eccentric by δ1 in the vertical direction.

The inner peripheral surface (cam surface) of the cam ring 1 is closest to the outer peripheral surface of the rotor 2 at a specific circumferential position (for example, the lowest position in FIG. 2), and the gap with the outer peripheral surface is minimized. Then, the working fluid is provided by the inlet port 1A of the cam ring 1, the specific circumferential position (bottom position in FIG. 2) and the circumferential position on the opposite side (top position in FIG. 2), and the exit port 1B of the cam ring 1. A flow path (in FIG. 2, the space indicated by the pump chambers α01, α02, and α1) is configured.
The working fluid flow path is defined by the outer peripheral surface of the rotor 2, the inner peripheral surface of the cam ring 1, and the inner surfaces of the side plates 4 and 5 (FIG. 1).

On the outer peripheral surface of the rotor 2, a plurality of vane grooves 2A extending in the radial direction are arranged at approximately equal intervals in the circumferential direction of the rotor 2 (six in the illustrated embodiment). Each of the six vane grooves 2A accommodates a vane 3, and when the rotor 2 rotates, the vane 3 is always urged outward in the radial direction, and the tip portion (tip portion outward in the radial direction) is always urged outward. It is configured to be in sliding contact with the inner peripheral surface (cam surface) of the cam ring 1.
In FIGS. 1 and 2, side plates 4 and 5 as plate members are arranged on both side surfaces of the cam ring 1 and the rotor 2 (the left and right sides in FIG. 1 and the side perpendicular to the paper surface in FIG. 2).
As described above, the gap regions α (pump chambers: α1, α01, α02,) are formed by the vanes 3 arranged adjacent to each other, the outer peripheral surface of the rotor 2, the inner peripheral surface of the cam ring 1, and the side plates 4 and 5. ...) Is defined (section).

In FIG. 2, an inlet port 1A and an outlet port 1B are provided on the outer periphery of the cam ring 1, and the inlet port 1A and the outlet port 1B are point-symmetrical (symmetrical with respect to the center line) with respect to the center of the inner diameter of the cam ring 1. It is formed in the position of.
In the pump case 6, a suction flow path 6A is provided at a position corresponding to the inlet port 1A of the cam ring 1, and a discharge flow path 6B is provided at a position corresponding to the outlet port 1B of the cam ring 1. The suction flow path 6A communicates with an incompressible working fluid supply source (not shown) via the inlet port 8A of the piping adapter 8, and the discharge flow path 6B communicates with the outlet port 9A of the piping adapter 9 (vane pump 10). Communicates with the destination of the incompressible working fluid (discharged from).

In FIGS. 1 and 2, when the electric motor 20 is driven to rotate the motor shaft 23, the rotor 2 connected to the motor shaft 23 rotates (in the direction of arrow R1 in FIG. 2). Then, as shown in FIG. 2, an incompressible working fluid (liquid or the like) flows in through the suction flow path 6A of the pump case 6 and the inlet port 1A of the cam ring 1, and is adjacent to the vane 3 arranged therein. It flows into the pump chambers α01 and α02 defined by the rotor 2 and the cam ring 1.
In the state shown in FIG. 2, since the pump chambers α01 and α02 communicate with the inlet port 1A of the cam ring 1, they do not correspond to a closed space.
In FIG. 2, the incompressible working fluid flow is indicated by arrow A.

The position of the pump chamber or the space α corresponds to the position in the circumferential direction of the cam ring 1 as the rotor 2 rotates, and the position indicated by the reference numeral α01, the position indicated by the reference numeral α02, and the position indicated by the reference numeral α1 in FIG. ..., And the size (volume) of the pump chamber or the space α changes as the movement is performed.
The working fluid is transferred to the outlet port 1B by the pump chamber α defined by the adjacent vanes 3, the rotor 2, and the cam ring 1, and the working fluid is sucked from the inlet port 1A due to the fluctuation (expansion / contraction) of the volume of the pump chamber α. , A head is added and the head is discharged from the outlet port 1B.
Reference numerals 1D in FIGS. 2 to 5 are communication grooves formed on the inner peripheral surface of the cam ring 1, and the details of the communication groove 1D will be described later.

Next, the pump chamber α1, the inlet port 1A of the cam ring 1, and the outlet port 1B will be described with reference to FIG.
As described above with reference to FIG. 2, the rotation of the rotor 2 (in the direction of arrow R1 in FIG. 2) allows the incompressible working fluid to flow from the inlet port 1A through the vanes 3A and 3B, the rotor 2 and the cam ring 1. It flows into the pump chamber (gap area) α01 defined by the defined pump chamber α01 (gap area), the vanes 3B and 3C, the rotor 2, and the cam ring 1 (arrow A).

At the moment shown in FIG. 3, the pump chambers α01 and α02 communicate with the inlet port 1A.
On the other hand, at the moment shown in FIG. 3, the pump chamber α1 defined by the vanes 3C, 3D, the rotor 2, and the cam ring 1 does not communicate with the inlet port 1A and does not communicate with the outlet port 1B. In other words, at the moment shown in FIG. 3, the pump chamber α1 (the gap region adjacent to the pump chamber α02 in the clockwise direction) is in a non-communication state with the inlet port 1A. On the other hand, at the moment shown in FIG. 3, the pump chamber α1 is in a non-communication state with the outlet port 1B, but is in a state immediately before communicating with the outlet port 1B. In other words, the pump chamber α1 communicates with the inlet port 1A of the cam ring 1 until just before the moment shown in FIG. 3, and immediately after the moment shown in FIG. 3, the pump chamber α1 communicates with the pump chamber α1. Communicates with exit port 1B.

At the moment shown in FIG. 3, the pump chamber α1 does not communicate with either the inlet port 1A or the outlet port 1B. Then, at the moment shown in FIG. 3, the pump chamber α1 exists at a position where its volume becomes maximum.
That is, the illustrated vane pump 10 has an inlet port 1A or an outlet except for the moment shown in FIG. 3 (the moment when the volume of the pump chamber α1 (gap region) defined by the adjacent vane 3, the rotor 2 and the cam ring 1 is maximized). Any of the ports 1B is configured to communicate with the pump chamber α1 (gap area).
As is clear from FIGS. 1 to 3, no auxiliary port is provided in the area between the inlet port 1A and the exit port 1B of the cam ring 1.
Reference numeral 1C in FIG. 3 is a through-hole, and the through-hole 1C will be described later with reference to FIG. 7.

The relative positional relationship between the pump chamber α1, the inlet port 1A, and the outlet port 1B will be further described with reference to FIG. Here, although the vane 3 and the vane groove 2A are not shown in FIG. 4, each of the virtual lines L1 to L6 extending radially outward from the rotation center of the rotor 2 shows the positions of the vane 3 and the vane groove 2A. ing.
As described above with reference to FIG. 2, the rotation center O1 of the rotor 2 having a substantially cylindrical shape and the inner diameter center O2 of the cam ring 1 having an inner peripheral surface (cam surface) having a diameter larger than the outer diameter of the rotor are designated by reference numeral δ1. It is eccentric by the amount indicated by.
At the moment shown in FIG. 4, the vane located on the virtual line L1 (not shown), the vane located on the virtual line L2 (not shown), the cam ring 1 and the pump chamber α1 (gap area) defined by the rotor 2 are cam rings. It does not communicate with the inlet port 1A of 1 and does not communicate with the exit port 1B.

However, while the rotor 1 rotates in the direction of arrow R1, the pump chamber α1 (gap region) does not communicate with either the inlet port 1A or the outlet port 1B at the moment shown in FIG. 4, that is, the pump chamber α1. Only at the moment when the volume of (gap area) is maximized.
That is, the volume of the pump chamber α1 expands (expands) until just before the moment shown in FIG. 4, and the pump chamber α1 (gap region) communicates with the inlet port 1A. Therefore, when the gap region α1 expands, the working fluid is supplied from the inlet port 1A to the gap region α1.
On the other hand, after the moment shown in FIG. 4, the volume of the pump chamber α1 decreases (contracts), but the pump chamber α1 (gap region) communicates with the outlet port 1B. Therefore, when the gap region α1 contracts to pressurize the incompressible working fluid, it communicates with the outlet port 1B, and the working fluid in the pump chamber α1 is discharged to the outlet port 1B.

Therefore, when the pump chamber α1 (gap region) expands (expands), the working fluid is supplied from the inlet port 1A, so that no cavity is formed in the pump chamber α1 and the moments shown in FIGS. After (the moment when the volume of the pump chamber α1 becomes maximum), even if the volume of the pump chamber α1 decreases and the working fluid is pressurized, the generation of noise due to the collapse of the cavity is prevented.
Further, since the pump chamber α1 communicates with the outlet port 1B immediately after the moment shown in FIGS. 3 and 4 (the moment when the volume of the pump chamber α1 becomes maximum), when the pump chamber α1 (gap region) contracts, The working fluid is not discharged from the outlet port 1B, the pressure of the working fluid does not rise, the occurrence of the so-called “confinement” phenomenon is prevented, and the generation of noise is also prevented.

Therefore, noise is prevented from being generated even if the auxiliary port is not formed in the region between the inlet port 1A and the outlet port 1B of the cam ring 1, and it is not necessary to perform complicated processing on the cam ring 1 and the pump body.
Further, since the inlet port 1A and the outlet port 1B are arranged so as to be point-symmetrical (symmetrical with respect to the center line) with respect to the center of the inner diameter of the cam ring 1 (arranged in the diameter direction), a bent portion is formed in the flow path. There is no need to form (elbows) or curved parts, resistance in the flow path of the working fluid is reduced, and efficiency is improved.

As described above, the communication groove 1D is formed on the inner peripheral surface of the cam ring 1.
FIG. 5 shows a state immediately after the pump chamber α1 (gap region) contracts from the moment when the volume becomes maximum (the moment shown in FIGS. 2 to 4) and communicates with the outlet port 1B. In FIG. 5, the positions of vanes 3C and 3D (FIG. 3) at the moment when the volume of the pump chamber α1 becomes maximum (the moment shown in FIGS. 2 to 4) are shown by virtual lines L1 and L2, respectively.
In the state of FIG. 5, that is, the state immediately after the pump chamber α1 communicates with the outlet port 1B, the rotor 2 rotates slightly in the direction of arrow R1 and the vane 3D is compared with the moment when the volume of the pump chamber α1 becomes maximum. Slightly enters the discharge port 1B side.

Here, in the state where the pump chamber α1 communicates with the inlet port 1A (the state before the moment when the volume of the pump chamber α1 becomes maximum), the pump chamber is passed through the suction flow path 6A (FIG. 2) and the inlet port 1A. When the flow velocity of the working fluid flowing into α1 (arrow A) is very high, the pressure in the pump chamber α1 decreases. Therefore, the pressure difference from the pressure of the high-pressure outlet port 1B may be much larger.
If the communication groove 1D is not formed on the inner peripheral surface of the cam ring 1, the moment when the volume of the pump chamber α1 becomes maximum when the pressure difference between the pump chamber α1 and the outlet port 1B is large (FIGS. 2 to 4). Immediately after the pump chamber α1 communicates with the outlet port 1B as shown in FIG. 5 after contracting from the state), the discharge pressure in the outlet port 1B acts in the pump chamber α1 (arrow P1 in FIG. 5). As a result, the pressure of the working fluid in the pump chamber α1 rises sharply, and noise is generated.
Further, as the pressure of the working fluid in the pump chamber α1 (gap region) rises, the increased pressure acts on the radial outer end of the vane 3, and the vane 3 is pushed back inward in the radial direction. It may end up. When the vane 3 is pushed back inward in the radial direction in the state shown in FIG. 5, a gap is formed between the inner peripheral surface of the cam ring 1 and the radial outer end of the vane 3, and the working fluid ( The liquid) leaks into the adjacent pump chamber (for example, the pump chamber α02).

On the other hand, in the illustrated embodiment, as shown in FIG. 5, a communication groove 1D is formed at a position corresponding to the pump chamber α1 (gap region) having the maximum volume on the inner peripheral surface of the cam ring 1. ing. The end of the communication groove 1D on the inlet port 1A side is in the vicinity of the inlet port 1A, but does not communicate with the inlet port 1A. Further, the end of the communication groove 1D on the exit port 1B side is in the vicinity of the exit port 1B, but does not communicate with the exit port 1B.
In FIG. 5, the pump chamber α1 (gap area) and the outlet port 1B communicate with each other (the communication portion is indicated by reference numeral E), and the pump chamber α1 and the inlet port 1A communicate with each other on the inner peripheral surface of the cam ring 1. It communicates via 1D.
Although not clearly shown in FIG. 5, the communication groove 1D is formed so as to have a relatively wide and shallow cross-sectional shape. The reason why the cross-sectional shape of the communication groove 1D is relatively wide and shallow will be described later with reference to FIG.

In FIG. 5, even if the discharge pressure in the outlet port 1B acts on the pump chamber α1 (gap region) (arrow P1), the pressure of the working fluid in the pump chamber α1 escapes to the inlet port 1A side via the communication groove 1D. (Arrow P2). Therefore, the pressure in the pump chamber α1 is not excessively increased, and no noise is generated.
Since the pressure in the pump chamber α1 is not excessively increased, the vane 3 is not pushed back inward in the radial direction, and a gap is formed between the inner peripheral surface of the cam ring 1 and the outer end in the radial direction of the vane 3. It is also prevented from being stowed. Then, the pressure of the pump chamber α1 does not act on the adjacent pump chamber (for example, the pump chamber α02).
When the pressure in the pump chamber α1 is released to the inlet port 1A side (arrow P2) by the communication groove 1D, the working fluid in the pump chamber α1 also leaks to the inlet port 1A side (pump chamber α02), and that amount Although the pump efficiency is reduced, the amount of the working fluid leaking is the amount of the working fluid leaking from the pump chamber α1 to the pump chamber α02 via the communication groove 1D, and the vane 3 is pushed back inward in the radial direction. Much less than the amount of leakage in the case. Therefore, there is no possibility that the pump efficiency is lowered by forming the communication groove 1D.

As described above, the cross-sectional shape of the communication groove 1D formed in the cam ring 1 is relatively wide and shallow.
According to the inventor's experiment, assuming that the communication groove 1D has a narrow and deep cross-sectional shape, for example, in FIG. 5, when the discharge pressure of the outlet port 1B acts on the pump chamber α1, the pump passes through the communication groove 1D. The amount of working fluid leaking from the chamber α1 to the pump chamber α02 increases.
On the other hand, if the communication groove 1D has a wide and shallow cross-sectional shape, the amount of working fluid (in the pump chamber α1) that leaks through the communication groove 1D becomes very small.
The experimental results will be described with reference to FIG.

In FIG. 6, the horizontal axis is the position in the width direction of the working fluid flow path in the pump chamber α1, the position in the radial direction in the pump chamber α1 in FIG. 5, and the right end in FIG. 6 is the position of the outer peripheral surface of the rotor 1. The left end of No. 6 indicates the position of the inner peripheral surface of the cam ring 1. The vertical axis in FIG. 6 shows the flow velocity of the working fluid.
FIG. 6A shows the flow velocity distribution of the working fluid when the communication groove 1D has a relatively wide and shallow cross-sectional shape, and FIG. 6B shows a case where the communication groove 1D has a narrow and deep cross-sectional shape. It is the flow velocity distribution of the working fluid in.

When the communication groove 1D has a relatively wide and shallow cross-sectional shape (shown in FIG. 6 (A)), the position in the width direction of the flow path is the working fluid on the inner peripheral surface of the cam ring 1 (the left end of FIG. 6 (A)). The flow velocity of is almost zero. Therefore, the flow rate of the working fluid flowing through the communication groove 1D formed on the inner peripheral surface of the cam ring 1 is very small, and the working fluid leaks to the inlet port 1A side (pump chamber α02) via the communication groove 1D. The flow rate is also very small.
On the other hand, when the width of the communication groove 1D is narrow and the cross-sectional shape is deep (in the case of FIG. 6B), the flow velocity of the working fluid does not change much depending on the position in the width direction of the flow path, and the inner peripheral surface of the cam ring 1 (FIG. 6). The flow velocity at 6 (B) at the left end) is much larger than the flow velocity at the same position (almost zero) in FIG. 6 (A). Therefore, the flow velocity and the flow rate of the working fluid flowing through the communication groove 1D become large, and the flow rate of the working fluid leaking to the inlet port 1A side (pump chamber α02) via the communication groove 1D also becomes large.
Therefore, it is preferable that the communication groove 1D has a relatively wide and shallow cross-sectional shape.

Next, a mechanism for supplying pressure to the vane groove 2A (a mechanism for performing pressure loading) for urging and projecting the vane 3 outward in the radial direction will be described mainly with reference to FIG. 7.
In FIG. 7, the open ends (upper and lower ends of FIG. 7) of the cam ring 1 accommodating the rotor 2 are covered with side plates 4 and 5.
The exit port 1B of the cam ring 1 is perforated with a through hole 1C penetrating to the side plate 4, and the side plate 4 is formed with a path 4A extending inward in the radial direction from the place where the through hole 1C communicates. ..

The side plate 4 is provided with an annular groove 4B formed so as to communicate the inner end portion 2AA in the radial direction at a position facing the inner end portion 2AA in the radial direction of the vane groove 2A. The annular groove 4B communicating with the radial inner end 2AA of the plurality of vane grooves 2A (six in the illustrated example) also communicates with the path 4A formed on the side plate 4.
Therefore, the boosted hydraulic fluid flowing through the outlet port 1B is supplied to the radial inner end 2AA of the vane groove 2A via the through hole 1C of the cam ring 1, the path 4A of the side plate 4, and the annular groove 4B. Be (introduced). The flow of such a working fluid is indicated by an arrow B in FIG.

As described above with reference to FIGS. 1 to 4, when the volume of the pump chamber α1 contracts due to the rotation of the rotor 2 from the moment shown in FIGS. 3 and 4, the working fluid in the pump chamber α1 is pressurized. It is discharged from the outlet port 1B (arrow A in FIG. 7).
A part of the working fluid that is pressurized and discharged from the outlet port 1B flows through the through port 1C, the path 4A, and the annular groove 4B, and is supplied (introduced) to the radial inner end portion 2AA of the vane groove 2A. Therefore, pressure loading is performed on the vane 3 in the vane groove 2A, and the vane 3 is urged outward in the radial direction. The force that urges the vane 3 outward in the radial direction is indicated by the arrow F in FIG.

A part of the working fluid pressurized and discharged through the through hole 1C of the outlet port 1B is introduced into the radial inner end 2AA of the vane groove 2A, and pressure loading is performed. It is not necessary to form a port in the region between the port 1A and the exit port 1B, and it is not necessary to perform complicated processing on the port.
Therefore, the cam ring 1 and the pump main body can be manufactured more easily, and the labor and cost for manufacturing can be further reduced.

It should be added that the illustrated embodiment is merely an example and is not a description intended to limit the technical scope of the present invention.
For example, the number of vanes formed in the rotor and the number of vanes arranged in the vanes are "6" in the illustrated embodiment, but other numbers such as "8", "10", etc. It can also be the number of.
Further, the drive source of the vane pump can be applied to an electric motor, an internal combustion engine, an output shaft of a transmission, and various other devices, and is not particularly limited.

1 ... Cam ring 1A ... Inlet port 1B ... Outlet port 1C ... Through hole 1D ... Communication groove 2 ... Rotor 2A ... Vane groove 2AA ... Radial inward end 3, 3A, 3B, 3C, 3D ... Vane (blade)
4, 5 ... Side plate 4A ... Path 4B ... Circular groove 6 ... Pump case 6A ... Suction flow path 6B ... Discharge flow path 7 ... Pump covers 8, 9 ... Piping adapter 8A ... Inlet port 9A ... Outlet port 10 ... Vane pump 20 ... Electric motors 21A, 21B, 21C ... Bush 22 ... Motor housing 23 ... Motor shaft 23A ... Connecting means 24 ... Motor rotor 25 ... Motor stator 26 ... Stator iron cores 27A, 27B ... Thrust washer 28 ... Frame α1, α01, α02 ... Pump chamber (gap area)

Claims (1)

A cam ring, a rotor whose rotation center is eccentric with respect to the inner diameter center of the cam ring, a vane groove formed radially outward from the rotation center of the rotor, and a vane that can move in the vane groove. In a vane pump with and
The working fluid is incompressible and
The cam ring has an inlet port and an exit port.
The inlet port and outlet port are formed at points symmetrical with respect to the center of the inner diameter of the cam ring, and the inlet port or outlet port is excluded except at the moment when the volume of the gap area defined by the adjacent vane, rotor and cam ring is maximized. Is formed at a position communicating with the gap region, no auxiliary port is formed in the region between the inlet port and the outlet port of the cam ring, and the inner peripheral surface of the cam ring has the maximum volume. A communication groove is formed at a position corresponding to the gap area.
It has a side plate that covers the open end of the cam ring
The outlet port of the cam ring has a through hole that communicates with either side of the side plate.
On the side plate on the side where the through hole communicates, a path is formed inward in the radial direction from the place where the through hole communicates.
The radial inner end of the vane groove of the rotor communicates with the annular groove formed on the side plate, and the annular groove communicates with the path formed on the side plate. Vane pump.

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