JPH0988807A - Motor integrated hydraulic pump device - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide a motor-integrated hydraulic pump device having a function of cooling an electric motor with hydraulic oil, without causing damage to the pump or reducing efficiency when the hydraulic oil is discharged and supplied, and always providing a favorable It provides a discharge flow. The oil immersion type electric motor and the hydraulic pump, which are coaxially coupled to each other, have an integrated unit structure, and an oil passage for guiding drain oil from the pump to the inside of the oil immersion type electric motor is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor-integrated hydraulic pump device in which an oil immersion type electric motor and a hydraulic pump are integrally provided.

[0002]

2. Description of the Related Art A conventional motor-integrated hydraulic pump device is disclosed in U.S. Pat. No. 3,672,793.

As shown in FIG. 2, this is one in which an electric motor 32, which is an oil immersion type electric motor, and a high pressure variable displacement pump 33, which is a hydraulic pump, are coaxially arranged and stored in one housing 31. The high-pressure variable displacement pump 33 is driven according to the rotation of the electric motor 32.

The hydraulic oil flowing in the housing 31 is introduced from a tank (not shown) to the inlet 3 provided in the housing 31.
It is guided into the housing 31 through 1a. The inside of the housing 31 is separated by a partition wall 36 into an electric motor chamber 37 and a pump drain chamber 44.

The inlet 31a is open to the electric motor chamber 37, and a centrifugal pump 34 is arranged in the electric motor chamber 37 in a chamber partitioned by a partition wall 35 for forced circulation of hydraulic oil. A part of the partition wall 35 on the side of the introduction port 31a is separated from the housing 31 to form a suction port 34a of the centrifugal pump, and a side facing the introduction port 31a is opened to form a discharge port 34b of the centrifugal pump.

Therefore, the hydraulic oil introduced from the introduction port 31a is divided into two flows, that is, a flow directly toward the electric motor 32 and a flow that is pressurized by the centrifugal pump 34 toward the electric motor 32.

As a result, the electric motor 32 is connected to the inlet 3
The whole is uniformly cooled by the flow of the hydraulic oil supplied from the two opposing sides of the 1a side and the discharge port 34b side of the centrifugal pump.

A high-pressure variable displacement pump 33 (hereinafter referred to as a pump) arranged on the other side of the electric motor 32 uses a stroke motion of a plurality of pistons 38 provided to suck and discharge hydraulic oil. It is a thing.

The suction port of the pump 33 is communicated with the inside of the electric motor chamber 37 by a conduit, and the working oil in the electric motor chamber 37 is sucked from the suction port 33a of the pump through this conduit and discharged from the pump. It is discharged from 33b to another device (not shown).

The discharge amount of the pump 33 is determined by the tilt angle of the swash plate 39, and the swash plate 39 has a return spring 40.
Since the tilt angle is controlled by the hydraulic operation piston 41 of the regulator that opposes the above, the discharge amount of the pump 33 is determined by the position of the hydraulic operation piston 41.

A pump drain chamber 44 in which a swash plate 39 is arranged
Is filled with drain oil generated by the operation of the pump 33, and this drain oil is discharged to the outside from a drain opening 44a provided in the housing 31.

Further, in this motor-integrated hydraulic pump device, a labyrinth seal member 43 is provided at a connecting portion between the partition wall 36 and the shaft 32a in order to separate the inside of the electric motor chamber 37 from the inside of the pump drain chamber 44. It is attached to an existing bearing 42 and prevents the drain oil from leaking to the electric motor chamber 37.

[0013]

However, in such a motor-integrated hydraulic pump device, since the hydraulic oil after cooling the electric motor is supplied to the pump,
Dust in the electric motor room gets mixed into the hydraulic oil (contamination)
Then, the problem that the pump is damaged occurs.

Further, since there is a flow path that circulates in the electric motor chamber upstream of the pump suction port, there is a problem in that the flow path resistance of the suction system of the high-pressure variable displacement pump is large and a reduction in pump efficiency cannot be avoided.

Further, the partition wall for separating the electric motor chamber and the pump drain chamber is not only configured not to hinder the rotation of the shaft, but also a labyrinth seal for isolating the pump drain chamber so that hydraulic oil does not leak to the electric motor chamber. The structure is complicated, and the assembly of the pump is complicated.

[0016] From the above, the present invention is a motor-integrated hydraulic pump device having a function of cooling an electric motor with hydraulic oil. It is an object of the present invention to provide a device that can obtain a good discharge flow. Another object is to provide a relatively small-sized motor-integrated hydraulic pump device with a simple structure.

[0017]

According to the present invention, the above object has an integrated unit structure of an oil immersion type electric motor and a hydraulic pump which are coaxially coupled, and drain oil generated from the hydraulic pump is immersed in the oil. This is achieved by a motor-integrated hydraulic pump device in which an oil flow path is formed that guides the oil to the inside of the mold type electric motor and then discharges the oil to the outside.

As a hydraulic pump which can be incorporated in such a motor-integrated hydraulic pump device, an axial piston type pump, a vane pump, a radial pump or the like can be used.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing an example of an embodiment of a motor-integrated hydraulic pump device according to the present invention. An example is shown in which an axial piston type pump (hereinafter referred to as a pump) provided with a mechanism-based regulator is configured integrally with an electric motor.

The inside of the housing 1 is divided into an electric motor chamber and a pump drain chamber by a partition wall 1a, and the electric motor and pump arranged in each chamber are connected by a shaft 3 having a coaxial structure. The shaft 3 may have an integral shaft structure on the motor side and the pump side.
Alternatively, separate shafts may be connected by a joint structure.

When the electric motor is in operation,
The rotor 2 in the electric motor chamber rotates to rotate the shaft 3 connected to the rotor 2 at a certain speed. A cylinder barrel 4 having a plurality of cylinder chambers arranged on the same circle in a plane perpendicular to the shaft 3 is provided at one end of the shaft 3 on the pump side. Therefore, when the shaft 3 rotates, the cylinder barrel 4 rotates together with the rotation of the shaft 3.

A piston 5 is slidably arranged in each cylinder chamber of the cylinder barrel 4. The heads of these pistons 5 are held in slidable contact with the swash plate 6 so that they can rotate. Therefore, shaft 3
When the cylinder barrel 4 rotates with the rotation, the head portion of the piston 5 makes a sliding contact orbital movement on the swash plate 6 about the rotation axis of the shaft 3.

Since the position of each piston 5 in the cylinder chamber at this time is determined by the tilt angle between the cylinder barrel 4 and the swash plate 6, the piston 5 is moved while the head portion makes a revolving motion on the swash plate 6. Will reciprocate in the cylinder chamber.

The head portion of the piston 5 is the cylinder barrel 4
When the piston 5 reaches the position closest to the position (called the bottom dead center position), the piston 5 minimizes the volume of the cylinder chamber, and the head portion of the piston 5 moves farthest from the cylinder barrel 4 (called the top dead center position). The piston 5 maximizes the volume of the cylinder chamber.

Here, the pump suction port 8a is opened directly to the end plate so that the working oil from a tank (not shown) can be directly sucked through a filter or the like. When the piston 5 moves in the direction of increasing the volume of the cylinder chamber, hydraulic oil is sucked into the cylinder chamber from the suction port 8a of the pump communicating with the tank, and conversely, the piston 5 moves in the direction of decreasing the volume of the cylinder chamber. At times, the pressure oil in the cylinder chamber is discharged to an external device (not shown) from the pump discharge port 8b provided in the end plate.

The displacement of the cylinder chamber due to the stroke movement of the piston 5 is determined by the inclination angle of the swash plate 6, and the swash plate 6 is inclined by the hydraulic operation piston 7 of the regulator mechanism that opposes the return spring 11. The turning angle is controlled.

The discharge port 8b has a branch passage for transmitting the discharge pressure to the hydraulic operation piston 7, and the hydraulic operation piston 7 receives the pressure oil introduced from this branch passage between its both end faces, and the sleeve bore. Move in. At this time, the tilt angle of the swash plate 6 increases or decreases depending on the amount and direction of movement of the hydraulic operation piston 7.

In the pump drain chamber, when the drain oil leaking from the cylinder chamber as the piston 5 slides and the discharge pressure of the pressure oil from the pump discharge port 8b are high, the swash plate control by the hydraulic operation piston 7 is performed. It is filled with drain oil discharged from the sleeve bore.

A drain hole 8 is provided in the upper region of the partition wall 1a, and the drain oil discharged into the pump drain chamber is introduced into the motor chamber to forcibly cool the inside of the electric motor by the drain oil. There is.

In this case, the bearing 10 provided at the connecting portion between the partition wall 1a and the shaft 3 is not provided with a seal member, so that drain oil can be leaked into the electric motor chamber also from here.

A drain opening 9 is provided on the upper housing wall of the electric motor chamber so that drain oil from the pump drain chamber is successively discharged through the electric motor chamber to the outside. It improves the circulation of drain oil and prevents the temperature from rising.

As described above, in the present invention, since the drain oil which is not related to the discharge flow of the pump is used for cooling the motor chamber, the pump can suck the working oil containing no foreign matter from the tank. . Further, since there is no extra flow path resistance in the suction system of the pump, the pump efficiency does not decrease.

Further, since it is not necessary to separate the pump drain chamber and the motor chamber with a labyrinth seal or the like, the structure is simple and the size can be reduced.

[0034]

As described above, according to the present invention,
Since the drain oil from the pump is used to cool the electric pump, it is possible to suck clean hydraulic oil that does not contain foreign matter into the pump, and therefore there is no loss in suction.
Moreover, it is possible to obtain a motor-integrated hydraulic pump device that is unlikely to be damaged by foreign matter.

Further, since it is not necessary to provide a seal member at the connecting portion of the shaft with the partition wall, and the pump drain chamber and the electric motor chamber do not have to be tightly sealed, the assembly is easy.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of a conventional motor-integrated pump.

[Explanation of symbols]

 1: Housing 1a: Partition wall 2: Rotor 3: Shaft 4: Cylinder barrel 5: Piston 6: Swash plate 7: Hydraulically operated piston 8: Drain hole 8a: Pump suction port 8b: Pump discharge port 9: Drain pipe 10 : Bearing 11: Return spring

Claims (1)

[Claims] 1. An oil flow having an integrated unit structure of an oil immersion type electric motor and a hydraulic pump which are coaxially coupled to each other, wherein drain oil generated from the hydraulic pump is introduced into the oil immersion type electric motor and then discharged to the outside. A motor-integrated hydraulic pump device characterized in that a passage is formed.