JPH07243376A - Variable displacement type hydraulic motor - Google Patents

Abstract

PURPOSE:To disassemble and maintain a swash plate without disassembling the whole of a motor by fixing a bearing block to support a trunnion shaft of the swash plate on an inside deep bottom part of a swash plate chamber from an opening of a main body case free to connect and disconnect. CONSTITUTION:A pair of trunnion shafts 16 having an axis Y orthogonal with a motor axis X at the center of a swash plate pressure receiving surface is projectively provided at an outer peripheral diagonal position of a swash plate 9, and a pair of bearing blocks 17 to internally fit and support each of the trunnion shafts 16 free to rotate is bolt-fixed on the inside deep bottom surface of a driving chamber D free to connect and disconnect. These bearing blocks 17 are inserted into a recessed part Da formed on the inner peripheral surface of a swash plate chamber, and the recessed part Da is used as a detent of a pressure plate 23 for braking. At the time of disassembling and maintaining the swash plate 9, bolt fixture of the bearing blocks 17 is released by removing a hydraulic block 3, extracting a cylinder block 7 from a rotation shaft 5 and exposing the swash plate 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement hydraulic motor used for driving a crawler type traveling device.

[0002]

2. Description of the Related Art The above-mentioned variable displacement hydraulic motor has a drive chamber having one side opening formed in a main body case connected and fixed to a frame on the machine body side, and the drive chamber is closed by a hydraulic block. A swash plate is tiltably installed on the back side of the cylinder, a cylinder block equipped with multiple plungers is rotatably installed on the inlet side, and the swash plate is pressed against the swash plate on the opposite side of the cylinder block. With a hydraulic cylinder that tilts, the output shaft that protrudes from the main body case and the rotating case that is freely fitted and supported on the main body case are interlockingly connected through a reduction mechanism inside the case. As a structure for supporting the swash plate,
As shown in FIG. 9, the bearing cover 3 in which the trunnion shaft 16 of the swash plate 9 is inserted and mounted in the outer peripheral diagonal position of the main body case 1.
A means for supporting the swash plate 9 so as to be tiltable about the trunnion axis Y is known.

[0003]

However, with this means, when it becomes necessary to disassemble and reassemble the swash plate 9 for maintenance, it is necessary to attach and detach the bearing cover 30 from the outer peripheral portion of the main body case 1. However, the operation was often difficult. For example, when the rotating case for output is fitted onto the main body case 1, the bearing cover 30 is required unless the entire motor is disassembled to separate the rotating case from the main body case 1.
Since it could not be attached and detached, there was room for improvement in handling and maintenance.

The present invention has been made in view of such a situation, and makes it possible to disassemble and maintain the swash plate relatively easily without disassembling the entire motor, and to provide the variable capacity type thereof. An object of the present invention is to make it possible to easily install a negative brake on a hydraulic motor.

[0005]

In order to achieve the above object, a variable displacement hydraulic motor according to the present invention forms a drive chamber having one side opening in a main body case of the variable displacement hydraulic motor and drives the same. Block the opening of the chamber with a hydraulic block,
A swash plate is tiltably arranged on the inner side of the drive chamber, and a cylinder block equipped with a number of plungers is rotatably arranged on the inlet side, and further, the cylinder block is integrally rotated on the outer periphery of the cylinder block. Free,
Further, a negative brake including a brake shoe that is slidable in the axial direction and a piston that presses the brake shoe against the end surface of the step formed at the boundary between the brake chamber and the swash plate chamber is provided. The trunnion shaft is supported through the bearing block, and the bearing block is inserted from the opening of the main body case through the bearing block insertion recess formed in the inner peripheral surface of the swash plate chamber. Removably fixed to the bottom by bolts, and between the brake shoe and the brake shoe pressure receiving end surface, the engagement piece that engages with the recess for inserting the bearing block and the recess for inserting the bearing block are closed. A pressure plate having a pressure receiving surface for the brake shoe is non-rotatably mounted.

[0006]

According to the above construction, by opening the drive chamber in the main body case and taking out the cylinder block, the swash plate and its shaft supporting portion are exposed in the inner part of the drive chamber, and the bearing block of the shaft supporting portion is fixed. By removing the bolt, the swash plate and the bearing block can be pulled out from the drive chamber. In other words, the attachment / detachment of the swash plate can be performed entirely through the opening of the drive chamber.

Further, since the pressure plate is attached to the step end face formed at the boundary between the brake chamber and the swash plate chamber, compared with the case where the brake shoe is directly contacted with the step end face. , It is possible to compensate for the reduction of the brake pressure receiving surface due to the concave portion for inserting the bearing block formed on the end surface of the step portion, and the manufacturing process of the brake pressure receiving surface that requires accuracy can be performed outside the main body case,
In other words, it can be done via a pressure plate that can be attached to and detached from the main body case, and the processing of the step end surface on the back side of the main body case, which is difficult to process, requires only low precision, and the brake pressure receiving surface can be processed. It will be easy.

[0008]

As described above, according to the present invention, since it is not necessary to operate the outer peripheral portion of the main body case for attaching and detaching the swash plate, it is not necessary to disassemble the entire motor and the rotating case is still attached. It was also possible to disassemble and maintain the swash plate, and it was possible to improve handleability and maintainability.

Further, by mounting a pressure plate on the step end surface formed at the boundary between the brake chamber and the swash plate chamber, the manufacturing process of the brake pressure receiving surface, which requires precision, can be performed outside the main body case. And finally,
The negative brake can be easily provided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 8 shows a drive unit when the variable displacement hydraulic motor M of the present invention is used as a drive motor capable of switching between high and low speeds of a crawler traveling device in a construction machine such as a backhoe. A cross section of the hydraulic motor M is shown.

The body case 1 of the hydraulic motor M is a flange 1
Two hydraulic blocks 3, which are connected and fixed to the outer surface of the track frame 2 via a and have a drive chamber D that opens toward the frame 2 side, and the openings of the drive chamber D are connected in series. It is blocked by 4.

A rotary shaft 5 is horizontally supported at the center of the drive chamber D, and a large number of axial type plungers 6 are provided.
A cylinder block 7, which is arranged along the circumferential direction, is attached to the rotary shaft 5. In addition, the rotary head 6a of the plunger 6 group is provided inside the drive chamber D with the thrust plate 8a.
A swash plate 9 is fixedly installed to receive it.

At the front part of the main body case 1, a rotating case 10 is provided.
Is rotatably fitted and mounted via a bearing 11, and a drive sprocket 13 engaging with a crawler belt 12 is attached to the rotating case 10. An output shaft 14 concentrically connected to the rotary shaft 5 is provided at the center of the front surface of the main body case 1, and the output shaft 14 and the rotary case 10 are housed in the rotary case 10 as a planetary gear type reduction mechanism. 15
Are interlockingly connected via.

On the outer circumference of the cylinder block 7, the seal
Rotatable integrally with the Linda block 7 and in the axial direction
Sliding brake shoe 20 and this brake shoe
As shown in FIG. 6, the view 20 is formed on the inlet side of the drive chamber D.
Large diameter brake room D ₁And behind the drive room D
Small diameter swash plate chamber D₂Step d formed at the boundary with
End face d₁Negati consisting of a piston 21 that presses against
A brake 22 is provided.

As shown in FIGS. 4 and 5, a pair of trunnion shafts 16 each having an axial center Y orthogonal to the motor axial center X at the center of the pressure receiving surface of the swash plate are provided at diagonally outer peripheral positions of the swash plate 9.
And a pair of bearing blocks 17 that rotatably internally support the trunnion shafts 16 are detachably fixed to the inner bottom surface of the drive chamber D by bolts.

[0016] The bearing block 17 is inserted through the recess Da for the bearing block inserted formed on the inner peripheral surface of the swash plate chamber D ₂ in the swash plate chamber D _2, the swash plate chamber D
_In the inlet end face of ₂ , that is, the end face d ₁ of the step d,
As shown in, a pressure plate 23 having an engagement piece 23a that engages with the recess Da and a pressure receiving surface 23b for the brake shoe 20 is non-rotatably mounted.

Further, as shown in FIG. 1, in the main body case 1, a pair of hydraulic cylinders 18 and 19 for changing the swash plate angle symmetrically with respect to the axis Y of the trunnion shaft 16 and an oil passage m to this. , H are formed, and when pressure oil is supplied only to the hydraulic cylinder 18 and the plunger 18a thereof advances, as shown in FIG.
As shown in FIG. 2, when the swash plate 9 is set to a large inclination angle to bring about a low speed state, and conversely, when pressure oil is supplied only to the hydraulic cylinder 19 and the plunger 19a advances, the swash plate 9 is moved as shown in FIG. The inclination angle of is set small so that a high speed state is brought about. Further, on the back surface of the swash plate 9, a seat surface s having a relatively small area for setting the inclination angle of the swash plate 5 by contact with the inner bottom surface of the drive chamber D is formed to be raised.

Further, as shown in FIG. 3, an oil passage n to the piston 21 is formed in the main body case 1, and when the swash plate 9 is operated, pressure oil is applied to the piston 21. When the negative brake 22 is supplied and the swash plate 9 is neutrally operated, the piston 2 is released.
The pressure oil of 1 is drained so that the braking action of the negative brake 22 is exerted.

According to the above construction, when it becomes necessary to disassemble and maintain the swash plate 9, the hydraulic chambers 3 and 4 are removed from the inside of the frame 2 to open the drive chamber D, and the cylinder block 7 from the rotary shaft 5 is removed. By removing the swash plate 9, the swash plate 9 together with the bearing block 17 can be extracted from the drive chamber D by releasing the bolt fixing of the pair of bearing blocks 17.

The hydraulic block 3 incorporates a flow path switching valve and a counterbalance valve for driving the hydraulic motor M in the forward direction or the reverse direction, and the hydraulic block 4 incorporates a shockless mechanism. There is.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a variable displacement hydraulic motor in a low speed state.

FIG. 2 is a vertical sectional side view of a variable displacement hydraulic motor at a high speed.

FIG. 3 is a transverse plan view of a variable displacement hydraulic motor.

FIG. 4 is a front view showing a swash plate support portion.

FIG. 5 is a side view of a main portion of a swash plate supporting portion.

FIG. 6 is a vertical sectional side view showing a disassembled state of the brake.

FIG. 7 is a perspective view of a brake shoe.

FIG. 8 is a side view showing a state in which the hydraulic motor is mounted on the traveling device.

FIG. 9 is a vertical sectional front view of a conventional swash plate support structure.

[Explanation of symbols]

1 Main body case 3 Hydraulic block 6 Plunger 7 Cylinder block 9 Swash plate 16 Trunnion shaft 17 Bearing block 18, 19 Hydraulic cylinder 20 Brake shoe 21 Piston 22 Negative brake 23 Pressure plate 23a Engaging piece 23d Pressure receiving surface D Drive chamber D ₁ Brake chamber D ₂ Swash plate chamber Da Recess for inserting bearing block d Step portion d ₁ Step end surface M Variable displacement hydraulic motor

Claims (1)

[Claims] 1. A drive chamber (D) having one side opening is formed in a main body case (1) of a variable displacement hydraulic motor (M), and the opening of the drive chamber (D) is closed by a hydraulic block (3). Then, a swash plate (9) is tiltably arranged on the back side of the drive chamber (D), and a cylinder block (7) equipped with a large number of plungers is rotatably arranged on the entrance side, and the cylinder is A brake shoe (20) which is integrally rotatable with the cylinder block (7) and is slidable in the axial direction on the outer periphery of the block (7), and the brake shoe (20) is defined as a brake chamber (D ₁ ). Negative brake (2) consisting of a piston (21) that presses against the end surface (d ₁ ) of the step (d) formed at the boundary with the swash plate chamber (D ₂ ).
2) is provided to support the trunnion shaft (16) of the swash plate (9) through a bearing block (17), and the bearing block (17) is provided through an opening of the main body case (1) and plate chamber (D ₂₎ by inserting inner peripheral surface through the formed bearing block insertion recessed portion (Da) detachably bolt fixed to the inner bottom portion of the swash plate chamber (D ₂₎ of said brake shoe ( 20) and the brake shoe pressure receiving end surface (d ₁ ), the engagement piece (23a) engaging with the recess (Da) for inserting the bearing block and the recess (Da) for inserting the bearing block are closed. A variable displacement hydraulic motor in which a pressure plate (23) having a pressure receiving surface (23b) for the brake shoe (20) is non-rotatably mounted.