JPH11257209A - Motor-integrated type hydraulic pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability of an accuracy detected by a potentiometer by arranging the potentiometer for detecting an inclination angle of a swash plate of a pump on the outside of a housing, and arranging a rotation transmitting shaft mechanism for transferring change of a rotating angle of the swash plate in the housing on the potentiometer arranged outside the housing. SOLUTION: In a hydraulic pump device, a potentiometer 10 is mounted on an outer wall of a housing 1 in a condition connected to a rotation transmitting shaft mechanism which extends to the outside of the housing 1 and while penetrating a bulk head 2 from a swash plate 8. The rotation transmitting shaft mechanism is mainly composed of a projection pin 8b concentrically with a rotary shaft core of the swash plate 8, a slant rotating angle detecting shaft 12, and a sealing cylinder 11 for separating those transmitting systems from an oil immersion. A detecting result of an inclination angle of the swash plate 8 found out by the potentiometer 10 on the basis of a rotating angle change rate of the swash plate 8 transmitted from the projection pin 8b through an inclination angle detecting shaft 12 and an input shaft 10a, is fed back to a regulator mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pump device used as a drive source in, for example, an injection molding machine, and more particularly to a motor-integrated hydraulic pump device.

[0002]

2. Description of the Related Art For example, there are actuators such as a mold clamping cylinder and an injection cylinder of an injection molding machine which are driven by hydraulic pressure. In recent years, as a drive source, suction of hydraulic oil is performed by utilizing a stroke motion of a piston. -In many cases, a so-called axial piston type variable displacement pump for performing discharge is coaxially arranged with an oil immersion type electric motor and a motor-integrated hydraulic pump device housed in one housing is used.

FIG. 2 shows an example of such a conventional integrated hydraulic pump device. That is, the inside of the housing 31 is partitioned by a partition wall 32 into an electric motor chamber 33 and a pump drain chamber 34, and an electric motor 35 and a pump 36 arranged in each chamber are connected by a coaxial shaft 37. is there.

In such a hydraulic pump device, when the electric motor 35 is operated, the rotor 3 in the electric motor room is not operated.
5a rotates, and rotates the shaft 37 connected to the rotor 35a at a predetermined speed. With the rotation of the shaft 37, the cylinder barrel 36a provided on the outer periphery of the shaft 37 at the pump-side end and having a plurality of cylinder chambers arranged along the shaft 37 also rotates.

A piston 36b is disposed in each cylinder chamber so as to be slidable in the direction of the shaft 37. The heads of these pistons 36b are held by swash plates 38 so as to be rotatable relative to each other. For this reason, when the cylinder barrel 36 a rotates with the rotation of the shaft 37, the head of the piston 36 b makes a sliding movement on the swash plate 38 around the axis of the shaft 37.

At this time, the position of each piston 36b in the cylinder chamber is determined by the inclination angle between the cylinder barrel 36a and the swash plate 38, and while the head portion orbits on the inclined swash plate 38, the position of each piston 36b is determined. Will reciprocate in the cylinder chamber.

As described above, the reciprocating motion of each piston 36b in the cylinder chamber causes a change in volume in each cylinder chamber. Then, when the piston 36a slides in a direction to increase the volume in the cylinder chamber, hydraulic oil is sucked into the cylinder chamber through a pump suction port 39a connected to an external oil tank (not shown), and the piston 36b is moved into the cylinder chamber. When it moves in the direction of reducing the volume of the hydraulic fluid, the hydraulic oil in the cylinder chamber is discharged from the pump discharge port 39b to an external device.

The pump drain chamber 34 is filled with drain oil or the like leaking from the cylinder chamber as the piston 36b slides. The drain oil is supplied from a drain hole 41 formed in the upper part of the partition wall 32 to the electric motor chamber. 33, circulates in the electric motor chamber 33 and
The electric motor 35 is forcibly cooled until the electric motor 35 is discharged from the upper drain opening 42 to the outside of the apparatus.

[0009] The displacement of the cylinder chamber due to the stroke movement of the piston 36a, that is, the amount of hydraulic oil discharged from the pump, is determined by the inclination angle of the swash plate 38. The inclination angle of the swash plate 38 is usually inclined. It is controlled by a hydraulically operated piston (not shown) of a regulator mechanism facing a return spring (not shown) connected to the plate 38.

Therefore, in order to control the tilt angle of the swash plate 38, it is necessary to detect the tilt angle of the swash plate 38 and feed back the result. So, conventionally,
A hydraulic pump device provided with a potentiometer 40 for detecting the inclination angle of the swash plate 38 in the pump section is used.

[0011]

In the conventional motor-integrated hydraulic pump device as described above, the potentiometer 40 is mounted on the partition wall 32 surrounding the pump 36, as shown in FIG. That is, the potentiometer 40 is exposed in the electric motor chamber 33 outside the partition 32 in the housing 31.

However, in the electric motor chamber 33, since the pump drain oil flowing through the drain hole 41 of the partition wall 32 for cooling the motor circulates, the potentiometer 40 is in an oil immersion state. I will.

Therefore, it is necessary to draw out the signal line from the potentiometer 40 to the outside of the housing 31, which not only complicates the device configuration but also causes a temperature drift due to a change in the oil temperature of the surrounding drain oil, which adversely affects the detection accuracy. It can also have an effect.

Further, when the potentiometer is arranged in the housing as described above, the potentiometer cannot be touched from the outside after the device is assembled, so that the initial value of the inclination angle can be finely adjusted or adjusted. The positional relationship with respect to the swash plate could not be changed.

SUMMARY OF THE INVENTION In view of the above problems, the present invention reduces the adverse effect from the surrounding environment, has higher reliability in the detection accuracy of a potentiometer, and has a structure in which the potentiometer can always be easily adjusted. An object is to obtain an integrated hydraulic pump device.

[0016]

According to a first aspect of the present invention, there is provided a motor-integrated hydraulic pump device according to the first aspect of the present invention, wherein an oil immersion type electric motor and an axial piston type variable displacement pump are provided in the same housing. And a motor-integrated hydraulic pump device housed in an integrated unit structure coaxially coupled with each other, wherein a potentiometer for detecting a swash plate inclination angle of the pump is provided outside the housing, and a potentiometer outside the housing is provided inside the housing. Is provided with a rotation transmission shaft mechanism for transmitting a change in the rotation angle of the swash plate.

In the present invention, by connecting the potentiometer to the rotation transmission shaft mechanism provided from the swash plate to the outside of the housing, the potentiometer can be arranged outside the housing of the hydraulic pump device.

Therefore, the potentiometer of the hydraulic pump according to the present invention does not cause a temperature drift due to a change in the temperature of the surrounding hydraulic oil unlike the conventional case in which the oil pump is in the oil immersion state, and provides a highly reliable swash plate. The detection result of the inclination angle is obtained.

Further, since a complicated structure for drawing out the signal line from the inside of the housing is not required, not only the structure of the apparatus is simplified, but also the adjustment of the potentiometer can be performed directly outside the housing at any time.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, a schematic configuration of a motor-integrated hydraulic pump device of a type for cooling an electric motor (oil immersion type electric motor) with drain oil from an axial piston type pump is shown in FIG. Is shown in the vertical section.

The motor-integrated hydraulic pump device according to the present embodiment has the same basic configuration as the conventional device of FIG. That is, the interior of the housing 1 is partitioned into an electric motor chamber 3 and a pump drain chamber 4 by a partition wall 2,
The electric motor 5 and the pump 6 disposed in each chamber are connected by a shaft 7 having a coaxial structure.

When the electric motor 5 is operated, the rotor 5a in the electric motor chamber 3 rotates, and the shaft 7 connected to the rotor 5a is rotated at a predetermined speed. A cylinder barrel 6a in which a plurality of cylinder chambers are formed along the axial direction of the shaft 7 on the same circle in a plane perpendicular to the shaft 7 is arranged on the outer periphery of the shaft 7 at the pump side end. The cylinder barrel 6a rotates with the rotation of the shaft 7.

A piston 6b is provided in each cylinder chamber so as to be slidable in the axial direction of the shaft 7, and the heads of the pistons 6b are respectively opposed to the swash plates 8 pivotally supported by cradle bearings 8a. The cylinder barrel 6a is rotatably held in sliding contact with the cylinder barrel 6a as the shaft 7 rotates.
Is rotated, the head portion of the piston 6b makes a sliding orbiting movement on the swash plate 8 around the axis of the shaft 7.

If the swash plate 8 is inclined at a predetermined angle,
The interval between the swash plate 8 and the cylinder barrel 6a changes in accordance with the inclination, and the piston 6b moves in the cylinder chamber in accordance with the change in the interval while the head portion orbits on the swash plate 8. , And reciprocate in the cylinder chamber.

Such a reciprocating motion of each piston 6b in the cylinder chamber causes a change in the volume in each cylinder chamber, and when the piston 6b slides in a direction to increase the volume in the cylinder chamber, an external oil tank (not shown). )), The hydraulic oil is sucked into the cylinder chamber through the pump suction port 9a, and moves in a direction to reduce the volume of the piston 6b in the cylinder chamber. Is discharged to

The pump drain chamber 4 has a piston 6
b, is filled with drain oil or the like leaking from the cylinder chamber along with the sliding of the b, and this drain oil flows into the electric motor chamber 3 from the drain hole 17 formed in the upper part of the partition wall 2,
The electric motor 5 is forcibly cooled until it circulates in the electric motor chamber 3 and is discharged from the drain opening 18 in the upper part of the housing 1 to the outside of the apparatus.

Further, in the hydraulic pump device according to the present embodiment, the potentiometer 10 is connected to the rotation transmission shaft mechanism extending from the swash plate 8 through the partition 2 to the outside of the housing 1 to connect the potentiometer 10 to the housing 1. It is provided on the outer wall.

The rotation transmitting mechanism according to the present embodiment includes a protruding pin 8 b concentric with the rotation axis of the swash plate 8, one end of which is connected to the protruding pin 8 b by a coupling 12 a, and the other end of which is an input of the potentiometer 10. Shaft 10a and coupling 13
And a sealing cylinder 11 for isolating these transmission systems from oil immersion.

Here, the sealing cylinder 11 and the housing 1
Oil leakage is prevented by interposing an O-ring 16 at the boundary between the two. Further, the tilt angle detection shaft 1 whose one end side protrudes outside the sealing cylinder 11 for connection with the protruding pin 8b.
An oil seal 14 was provided between 2 and the sealing cylinder 11 to prevent oil leakage into the sealing cylinder 11.

The displacement of the cylinder chamber due to the stroke movement of the piston 6b determines the amount of hydraulic oil discharged from the pump. The volume is set by the inclination angle of the swash plate 8. The inclination angle is usually the swash plate 8
Is controlled by a hydraulically operated piston (not shown) of a regulator mechanism opposed to a return spring (not shown) connected to the control valve. At this time, a detection result of the swash plate 8 inclination angle obtained by the potentiometer 10 based on the rotation angle change amount of the swash plate 8 transmitted from the protruding pin 8b via the inclination angle detection shaft 12 and the input shaft 10a. Is fed back to the regulator mechanism to perform a control operation so that a desired inclination angle is obtained.

In the hydraulic pump device according to the present embodiment having the above-described configuration, since the potentiometer 10 is mounted on the outer wall of the housing 1, adjustment such as setting of an initial value is performed as needed when detecting the inclination angle of the swash plate 8. I can do it. Further, the detection result obtained from the potentiometer 10 is highly reliable because it is not in an environment that causes a temperature drift as in the case of oil immersion.

In the above embodiment, the hydraulic device having the swash plate of the type pivoted to the cradle bearing has been described, but the present invention is not limited to this swash plate type.
For example, it may be pivoted by trunnion bearings. In this case, the swash plate trunnion shaft may be extended to the outside of the housing, and may also serve as a rotation transmission shaft mechanism connected to the potentiometer.

Further, in the motor-integrated hydraulic pump device of the above embodiment, the drain oil of the pump 6 is supplied to the electric motor 5
Although the type in which the hydraulic oil used for cooling the oil flows out from the pump drain chamber 1 to the electric motor chamber 3 has been described, the present invention is not limited to this, and for example, the operation oil previously introduced into the electric motor chamber may be used. It is similarly effective if a motor-integrated hydraulic pump device in which an axial piston variable displacement pump is coaxially coupled to an oil immersion type electric motor, such as a hydraulic pump device that sucks oil from a pump suction port.

[0034]

As described above, according to the present invention,
There is no need to draw out signal lines etc. from inside the housing to the outside, so that the device can be configured more easily, the tilt angle of the swash plate by the potentiometer can be detected with high accuracy, and the potentiometer can be easily adjusted. is there.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a schematic configuration of a motor-integrated hydraulic device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing an example of a conventional motor-integrated hydraulic device.

[Explanation of symbols]

 1, 31: housing 2, 32: partition wall 3, 33: electric motor chamber 4, 34: pump drain chamber 5, 35: electric motor 5a, 35a: rotor 6, 36: pump 6a, 36a: cylinder barrel 6b, 36b : Piston 7, 37: Shaft 8, 38: Swash plate 8a, 38a: Cradle bearing 8b: Protruding pin 9a, 39a: Pump suction port 9b, 39b: Pump discharge port 10, 40: Potentiometer 10a: Input shaft 11: Seal Cylinder 12: Tilting angle detection axis 13, 15: Coupling 14: Oil seal 16: O-ring 17, 41: Drain hole 18, 42: Drain opening

Claims (1)

[Claims] 1. An oil immersion type electric motor in the same housing,
A motor-integrated hydraulic pump device in which an axial piston type variable displacement pump is housed in an integrated unit structure coaxially coupled, wherein a potentiometer for detecting a swash plate inclination angle of the pump is installed outside a housing, and the housing A motor-integrated hydraulic pump device, wherein a rotation transmission shaft mechanism for transmitting a change in the rotation angle of a swash plate inside a housing to an external potentiometer is provided.