JP2592588Y2 - Hydraulic vane pump - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an equilibrium type constant discharge hydraulic vane pump, and more particularly to an improvement for reducing the pulsation of the discharge pressure.

[0002]

2. Description of the Related Art In an equilibrium type constant discharge hydraulic vane pump, it is necessary to push up a vane in order to surely contact the tip of each vane with the inner surface of a cam ring. Conventionally, this vane push-up mechanism is achieved by the centrifugal force of the vane's own weight when the pump is started, and by applying its own discharge pressure to the vane bottom during the subsequent rotation.

[0003] Various methods are known for applying their own discharge pressure to the bottom of the vane. In any case, when the pump is started, the vane is ejected by centrifugal force.
It is necessary to increase the minimum number of revolutions at startup to a certain level or more, and it is easily affected by the viscosity of hydraulic oil.

In the suction section, a part of the discharge pressure oil is used for pushing up the vane. Therefore, the pump discharge flow rate varies according to the shape of the cam ring profile in the suction section although the discharge amount is several% or less, and the pressure is reduced. Pulsation causes operation noise.

[0005] In this suction section, a high self-discharge pressure acts on the bottom of the vane, while a low suction pressure is applied at the tip of the vane, so that the balance of power is lost at both ends of the vane. For this reason, the frictional force between the cam ring at the tip of the vane and the cam ring is increased, the efficiency is reduced, and both the cam ring and the vane are liable to wear, so that high-grade materials have to be used for them.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems of the prior art and to secure a stable performance at the time of starting and to reduce pulsation of discharge pressure and reduce noise. Another object of the present invention is to provide a balanced constant-discharge hydraulic vane pump capable of obtaining high efficiency by reducing wear of a cam ring and a vane.

[0007]

According to the first aspect of the present invention, there is provided a balanced constant discharge hydraulic vane pump according to the present invention, wherein a vane orbiting in a cam ring by a rotor driven by a rotary shaft is a vane back pressure groove. In the balanced constant discharge hydraulic vane pump, which is pushed up toward the cam ring by the hydraulic pressure applied to the base of each vane, the pump chamber formed between the orbiting vanes is connected to the suction port. An independent first vane back pressure groove for the suction section leading to the pump, and a separate second vane back for the discharge section leading to the discharge port where the pump chamber formed between the orbiting vanes communicates with the discharge port. A pressure groove, which is driven by the rotary shaft to suck the pressure oil on the suction port side and discharge the pressure oil to the first port.
An auxiliary pump for supplying to the vane back pressure groove, a pressure control valve for controlling the discharge pressure of the auxiliary pump, and a part of the discharge pressure oil from the discharge port to the second vane back pressure groove. And a pressure transition section between the suction section and the discharge section.
The auxiliary pump is located in the trapped pump chamber between
And an opening for supplying pressure oil discharged from the pump .

[0008]

[0009]

According to the present invention, the suction section and the discharge section of the equilibrium type constant discharge hydraulic vane pump have independent vane back pressure grooves, and the discharge pressure of the vane is guided to the vane back pressure grooves in the discharge section. Pressure oil from, for example, a built-in auxiliary pump driven by a common rotary shaft is guided to the vane back pressure groove in the section at a pressure controlled by a pressure control valve. Accordingly, in the hydraulic vane pump of the present invention, the vane is not pushed up in the suction section by its own discharge pressure, but the discharge pressure oil is supplied from the auxiliary pump driven by the common rotary shaft while controlling the pressure. It is done by doing.

The cam ring profile of the equilibrium type constant discharge vane pump has a long diameter perfect circle section from the suction section to the discharge section and a short diameter perfect circle section from the discharge section to the suction section. Each round section is for shutting off the discharge port and the suction port by the vane, and in the suction section from the short round section to the long round section, the vane is pushed up according to the cam ring profile, and the long diameter is changed. Conversely, in the discharge section from the perfect circle section to the short diameter perfect circle section, the vane is pushed down according to the cam ring profile.

According to the present invention, since the vane back pressure groove in the discharge section communicates with its own discharge port independently of the vane back pressure groove in the suction section, the vane is pushed down by the cam ring profile in the discharge section. That means that there is also a discharge action at the bottom of the vane,
Therefore, a constant discharge amount can be obtained regardless of the thickness of the vane or the cam ring profile in the discharge section.

In the suction section, since the discharge pressure oil from the built-in auxiliary pump, which is commonly driven by the rotating shaft, is supplied to the vane back pressure groove at a controlled pressure, not the discharge pressure oil of the suction section itself, It is possible to always obtain a stable start-up characteristic compared to the push-up of the vane by the centrifugal force at the time,
Further, by selecting this controlled pressure so as to have a constant relationship with, for example, the pump discharge pressure, or by always selecting the pressure appropriately, the pressing force of the vane against the cam ring can be reduced to the minimum necessary. , The efficiency is kept good, the wear of the cam ring and the vane is also reduced, and the life can be extended without using a high-grade material.

The hydraulic oil used in the hydraulic vane pump is not an ideal incompressible fluid. In actuality, the hydraulic oil confined between the vanes in the long circular section is changed from the low pressure on the suction port side to the high pressure on the discharge port side. A certain amount of compression is required to make the transition to.

In the present invention, the amount of compression is not supplied from the discharge port side, but is supplied from the other pump, so that the discharge amount is not affected by the compression amount as a result. However, in this case, the setting of the supply pressure from the another pump is the same as the discharge pressure of the vane pump.

[0015]

FIG. 1 shows the configuration of an embodiment of the present invention. In the figure, a vane pump main body includes a rotor 2 in a cam ring 1.
And the vanes 3 are attached to the rotor 2 at equal intervals,
An equilibrium constant discharge pump in which the rotor is driven to rotate by the rotating shaft 10 is configured. A pair of suction ports 4 is provided on the end plate that closes the pump chamber in the cam ring at the end face.
And a pair of discharge ports 5 are provided on a diagonal line, and a pair of vane back pressure grooves 6 for introducing pressure oil to the bottom 8 of each vane in the suction section, and pressurized oil to the bottom 8 of each vane in the discharge section. And a pair of vane back pressure grooves 7 are provided independently of each other.

In a pair of vane back pressure grooves 6 for introducing pressure oil to the bottom of each vane in the suction section, a built-in auxiliary pump 20 which is rotationally driven by a common driving motor (not shown) together with the rotating shaft 10 is provided. Is introduced at a pressure controlled by the pressure control valve 21 through the passage 12, while a pair of vane back pressure grooves 7 for introducing pressure oil to the bottom of each vane in the discharge section includes: The own discharge pressure oil is introduced from the discharge port 5. This auxiliary pump 2
0 can be constituted by, for example, a gear pump or the like incorporated in the end of the vane pump main body.

In the pressure transition section in which the hydraulic oil confined between the vanes transitions from the low pressure on the suction port side to the high pressure on the discharge port side in the long diameter perfect circle section, there is a vane gap generated in the pressure transition section. An opening 9 for supplying the discharge pressure oil from the auxiliary pump 20 is provided in the confined chamber.

The amount of supply by the auxiliary pump 20 shown in FIG. 1 is set to be slightly larger than the amount of oil used by the lift amount of the vane 3, and the pressure control valve 21 for controlling the pressure is controlled by the pressure control valve 21 shown in FIG. As shown in FIG. 2, various structures and characteristics having various structures and characteristics can be used according to purposes, as shown in several schematic structures and pressure control characteristics with respect to the discharge pressure of the vane pump.

FIG. 2A shows a pressure control valve with pilot relief for controlling the discharge pressure of the auxiliary pump 20 by using the pressure from the discharge port 5 of the vane pump as the pilot pressure. The discharge pressure of the auxiliary pump is changed to follow the discharge pressure of the vane pump in a polygonal manner by discharging to the tank line with the spring set pressure. The pressure control valve shown in FIG. 2A is mainly incorporated for the purpose of improving insufficient vane lifting at the time of starting the pump and preventing wear (high efficiency) due to excessive vane lifting force in the suction section.

FIG. 2B shows that the discharge pressure of the auxiliary pump 20 is guided from the through hole 24 of the main valve body 23 to the pilot relief valve 25, and the spring set pressure of the pilot relief valve 25 is independent of the discharge pressure of the vane pump. The discharge pressure of the auxiliary pump 20 is controlled to a constant pressure determined by the following equation. This control valve is also effective for measures at the time of pump startup and wear measures in the suction section.If the discharge pressure of the auxiliary pump is set lower than the discharge pressure of the vane pump depending on the application,
Structurally, the pilot relief valve 25 may be omitted and a direct acting relief valve may be used.

The one shown in FIG. 2C is mainly incorporated for the purpose of reducing the pulsation of the discharge pressure. In this case, the vane formed in the pressure transition section between the suction port and the discharge port is used. Since it is necessary to increase the pressure in the confined chamber between the two to the discharge pressure of the vane pump, the auxiliary pump 2
The discharge pressure of 0 is controlled to be always the same as the discharge pressure of the vane pump. Along with this, insufficient vane lifting at the start of the pump is also improved, but the vane lifting force during operation is not significantly improved.

The structure shown in FIG. 2D is incorporated when having an intermediate function between the structure shown in FIGS. 2A and 2B and the structure shown in FIG. 2C. The discharge pressure of the auxiliary pump 20 is controlled in a proportional relationship.

Referring to FIG. 1, a rotating shaft 10 is
When the auxiliary pump 20 is driven, the rotor 2 rotates while the pressure oil discharged from the auxiliary pump 20 is introduced into the vane back pressure groove 6 in the suction section, whereby the vane 3 in this section is displaced by the cam ring 1 with an appropriate force. And is moved by the rotation of the rotor 2.

FIG. 3 is a developed view of the cam ring profile and vane movement from the suction section to the discharge section, and FIG. 4 is a view showing a state of formation of a closed chamber between the suction port 4 and the discharge port 5 between the vanes. .

In the suction section, the vane 3 is
The pump is pushed up by the controlled pressure supplied from the auxiliary pump 20, and the suction operation is performed while the tip is in contact with the cam ring. The supply of the pressure oil to the vane back pressure groove 6 according to the lift of the vane 3 is performed from the auxiliary pump 20, and is independent of the discharge amount of the self.

In the pressure transition section between the suction port 4 and the discharge port 5, an opening 9
Is supplied from the auxiliary pump 20 for the amount of compression, which is irrelevant to its own discharge amount.

In the discharge section, the vane 3 is pushed down by the profile of the cam ring 1, whereby pressure oil is also discharged from the vane back pressure groove 7 to the discharge port 5. Therefore, pulsation of the discharge amount does not occur, and the operation sound becomes extremely quiet.

[0028]

[Effect of the invention] As described above, according to the invention,
In the suction section, discharge pressure oil from another pump was controlled and supplied to the van back pressure groove instead of its own discharge pressure oil, so it was always stable compared to pushing up the vane due to centrifugal force at startup. The starting characteristics can be obtained, and by appropriately selecting this controlled pressure, the pressing force of the vane against the cam ring can be reduced to the minimum necessary, and the frictional force at the vane tip can be reduced. In this case, the efficiency can be kept good, the wear of the cam ring and the vane can be reduced, and the life can be prolonged without using a high-grade material. Ma
In addition, the present invention relates to a pressure transition between a suction section and a discharge section.
The above-mentioned auxiliary is installed in the trapped pump room between vanes generated in the section.
It has an opening to supply pressure oil discharged from the pump.
The hydraulic oil flows from the low pressure on the suction port side to the discharge port side.
Pressure oil for the amount of compression required to transition to high pressure
Supplied from the auxiliary pump instead of the discharge port side,
This has the effect of being unaffected irrespective of the discharge amount.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a configuration of a balanced constant discharge hydraulic vane pump according to an embodiment of the present invention.

FIGS. 2A to 2D are explanatory views showing a schematic structure example of a pressure control valve for controlling a discharge pressure of an auxiliary pump and some examples of pressure control characteristics.

FIG. 3 is a development view of a cam ring profile and vane movement from a suction section to a discharge section.

FIG. 4 is an explanatory view showing a state of forming a confined chamber between vanes between a suction port and a discharge port.

[Explanation of symbols]

 1: cam ring 2: rotor 3: vane 4: suction port 5: discharge port 6: vane back pressure groove (suction section) 7: vane back pressure groove (discharge section) 8: vane bottom chamber 9: opening 10: rotating shaft 20 ： Auxiliary pump (another pump) 21 ： Pressure control valve

Claims (1)

(57) [Scope of request for utility model registration] 1. A vane orbiting in a cam ring by a rotor driven by a rotating shaft is pushed up from the vane back pressure groove toward the cam ring by hydraulic pressure applied to a base of each vane. In a balanced, constant discharge hydraulic vane pump, a pump chamber formed between the orbiting vanes has an independent first vane back pressure groove for a suction section leading to a suction port; An independent second vane back pressure groove for a discharge section in which a pump chamber formed between the pump ports communicates with a discharge port, and driven by the rotating shaft to suck pressure oil on the suction port side. An auxiliary pump for supplying a discharge pressure oil to the first vane back pressure groove, a pressure control valve for controlling a discharge pressure of the auxiliary pump, and a discharge port for the second vane back pressure groove. Of pressure oil discharged from And passage means for guiding occurs at a pressure transition section between the suction section and the discharge section
In the confined pump room between the vanes,
A hydraulic vane pump comprising: an opening for supplying discharge pressure oil .