JP2831915B2 - Swash plate support structure for variable displacement hydraulic motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In a variable displacement hydraulic motor described above, a drive chamber opened toward the frame side is formed in a main body case which is connected and fixed to a frame on the body side, and this opening is closed by a hydraulic block to form an axial type hydraulic motor. Along with rotatably supporting a cylinder block having a large number of plungers arranged therein in the drive chamber, and inside the drive chamber,
Equipped with a swash plate that receives the tip of each plunger,
An output shaft protruding from the main body case and a rotating case freely fitted and supported on the main body case in a freely rotatable manner are interlockingly connected via a speed reduction mechanism inside the case interior, and the swash plate is tiltably supported by the main body case. In addition, the main body case is provided with a hydraulic cylinder that presses and tilts the swash plate from the side opposite to the plunger. As a structure for supporting the swash plate, as shown in FIG. The trunnion shaft 16 provided at the outer diagonal position is supported by the bearing cover 30 inserted and mounted at the outer diagonal position of the main body case 1, and the swash plate 9 is supported so as to be tiltable about the trunnion shaft axis Y. Means are known.

[0003]

However, according to this means, if 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. Yes, the operation was often difficult. For example, when the output rotary case is fitted to the main body case 1, the bearing cover 30 must be disassembled unless the entire motor is disassembled to separate the rotary case from the main case 1.
Cannot be attached or detached, leaving room for improvement in handling and maintenance.

The present invention has been made in view of such circumstances, and has as its object to make it possible to relatively easily disassemble and maintain a swash plate without disassembling the entire motor.

[0005]

In order to achieve the above object, a swash plate support structure for a variable displacement hydraulic motor according to the present invention is provided on a body case which is connected and fixed to a frame on the body side of the body and faces the frame side. While forming an open drive room,
This opening is closed by a hydraulic block, and a cylinder block having a large number of axial type plungers arrayed therein is rotatably supported inside the drive chamber, and a distal end of each plunger is provided at the inner part of the drive chamber. The swash plate for receiving the swash plate is fixed, and the output shaft protruding from the main body case and the rotating case which is fitted to the main body case so as to be freely rotatable are interlocked and connected via a speed reduction mechanism inside the case, and A swash plate support structure for a variable displacement hydraulic motor, comprising a main body case equipped with a hydraulic cylinder for tilting the swash plate by pressing the swash plate from a side opposite to the plunger while supporting the plate in a tiltable manner. A pair of trunnion shafts are protruded concentrically at diagonal positions of the outer periphery, and each trunnion shaft is fitted and supported in a bearing block, respectively, and the pair of trunnion shafts is Characterized in that the inner bottom portion of the dynamic chamber are detachably bolted.

[0006]

According to the above construction, the swash plate and its shaft support are exposed inside the drive chamber by opening the drive chamber in the main body case and taking out the cylinder block.
The swash plate and the bearing block can be pulled out of the drive chamber by removing the fixing bolt of the bearing block of the bearing. That is, the mounting and dismounting of the swash plate can all be performed from the opening of the drive chamber.

[0007]

Therefore, according to the present invention, since the operation from the outer peripheral portion of the main body case is not required for mounting and dismounting the swash plate, it is not necessary to disassemble the entire motor, and the rotary case is mounted. The disassembly and maintenance of the swash plate was also possible, and the handling and maintenance were improved.

[0008]

FIG. 6 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, and FIG. A cross section of the hydraulic motor M is shown. The main body case 1 of the hydraulic motor M is connected and fixed to the outer surface of a body frame (track frame) 2 via a flange 1a, and has a drive chamber D that opens toward the frame 2 side. The part is closed by two hydraulic blocks 3, 4 connected in series. At the center of the driving chamber D, a rotary shaft 5 is horizontally supported, and a cylinder block 7 in which a number of axial plungers 6 are arranged along the circumferential direction is attached to the rotary shaft 5. Further, a swash plate 9 for receiving the rotating head 6a of the plunger group 6 via the thrust plate 8 is fixedly provided in the inner side of the drive chamber D.

A rotating case 10 is provided at the front of the main body case 1.
Is rotatably fitted via a bearing 11, and a driving sprocket 13 that engages with a crawler belt 12 is attached to the rotating case 10. At the center of the front surface of the main body case 1, there is provided an output shaft 14 concentrically connected to the rotary shaft 5, and the output shaft 14 and the rotary case 10 are provided inside the rotary case 10 and are provided with a planetary gear type reduction mechanism 15.
Are interlocked and linked.

As shown in FIGS. 3 and 4, the swash plate 9
A pair of trunnion shafts 1 having an axis Y orthogonal to the motor axis X at the center of the swash plate pressure receiving surface at diagonal positions on the outer periphery of
6, a pair of bearing blocks 17 for rotatably fitting and supporting the respective trunnion shafts 16 are detachably bolted to the inner bottom surface of the drive chamber D.

The main body case 1 includes a trunnion shaft 16.
A pair of hydraulic cylinders 18 and 19 for changing the swash plate angle and oil passages l and h are formed symmetrically with respect to the axis Y of the cylinder. When 18a advances, the inclination angle of the swash plate 9 is set to be large as shown in FIG.
When the pressure oil is supplied only to the hydraulic cylinder 19 and the plunger 19a advances, as shown in FIG. 2, the inclination angle of the swash plate 9 is set small, and a high-speed state is brought about. Here, on the rear surface of the swash plate 9, a bearing 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 so as to protrude.

According to the above configuration, when it becomes necessary to disassemble and maintain the swash plate 9, the drive chamber D is opened by removing the hydraulic blocks 3 and 4 from the inside of the frame 2, and the cylinder block 7 is removed from the rotary shaft. As a result, the swash plate 9 is exposed, and the bolt fixing of the pair of bearing blocks 17 is released, whereby the swash plate 9 can be pulled out of the drive chamber D together with the bearing blocks 17.

FIG. 5 shows a hydraulic circuit diagram for driving the hydraulic motor M. In the figure, reference numeral 20 denotes a traveling control valve, which is operated by switching to a mechanical type or a hydraulic pilot type in association with a control lever (not shown), thereby supplying hydraulic oil to a port P1 or a port P2 to provide a hydraulic motor M. Can be driven forward or reverse.
Reference numeral 21 denotes a forward drive oil passage f and a reverse drive oil passage r.
A high-pressure selection shuttle valve is connected to the swash plate angle changing hydraulic cylinder 18 or 19 for supplying the selected forward rotation or reverse rotation driving pressure oil.
Reference numeral 22 denotes a hydraulic pilot type flow path switching valve interposed between the shuttle valve 21 and the hydraulic cylinders 18 and 19, and in a normal state where no pilot pressure is applied, as shown in FIG. The oil is supplied to an oil passage l to the hydraulic cylinder 18 and an oil passage h to the other hydraulic cylinder 19 communicates with a drain oil passage d. When a pilot pressure is applied, the hydraulic oil from the shuttle valve 21 Is supplied to an oil passage h to a hydraulic cylinder 19 and an oil passage l to the other hydraulic cylinder 18 is connected to a drain oil passage d. Then, the shuttle valve 2 is attached to the hydraulic block 3.
1. Flow path switching valve 22, and counterbalance valve 2
The shockless mechanism 24 is incorporated in the hydraulic block 4.

Normally, the pilot pressure is not applied to the flow path switching valve 22, and the pressure oil is supplied only to the low-speed hydraulic cylinder 18, and as shown in FIG. When the pilot pressure is applied to the flow path switching valve 22 by switching the pilot valve 24 by the pedal operation to maintain the pressure in the attitude, and the flow path switching valve 22 is switched to the reverse position,
The pressure oil is supplied only to the high-speed hydraulic cylinder 19, and the swash plate 9 is tilted to a high-speed attitude and pressed and held as shown in FIG.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the accompanying drawings.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a variable displacement hydraulic motor according to the present invention at a low speed.

FIG. 2 is a longitudinal side view of the variable displacement hydraulic motor according to the present invention in a high-speed state.

FIG. 3 is a front view showing a swash plate support.

FIG. 4 is a side view of a main part of the swash plate support.

FIG. 5 is a hydraulic circuit diagram

FIG. 6 is a side view of a state where the hydraulic motor is mounted on the traveling device.

FIG. 7 is a vertical sectional front view of a conventional swash plate support structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body case 2 Frame 3 Hydraulic block 6 Plunger 7 Cylinder block 9 Swash plate 10 Rotating case 15 Reduction mechanism 16 Trunnion shaft 17 Bearing block 18, 19 Hydraulic cylinder D Drive room

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Akira Tsuda 64 Ishizukita-cho, Sakai City, Osaka Prefecture Inside Kubota Sakai Plant (72) Inventor Tetsuo Ishioka 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Manufacturing Co., Ltd. In-house (72) Inventor Hiroya Hanano 64 Ishizu-Kitacho, Sakai-shi, Osaka Kubota Sakai Works Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) F03C 1/24

Claims (1)

(57) [Claims] A drive chamber (D) opening toward the frame (2) is formed in a main body case (1) connected and fixed to a frame (2) on the body side, and the opening is formed in a hydraulic block (3). ), And rotatably supports a cylinder block (7) having a large number of axial-type plungers (6) arranged therein, inside the drive chamber (D), and inside the drive chamber (D). A swash plate (9) for receiving the tip of each plunger (6) is fixedly mounted on the portion, and the output shaft (14) protruding from the main body case (1) and the main body case (1) are freely rotatably externally mounted. The rotating case (10) fitted and supported is interlocked and connected via a speed reduction mechanism (15) inside the case,
And a hydraulic cylinder (18) for tilting the swash plate (9) by tilting the swash plate (9) from the side opposite to the plunger (6) while supporting the swash plate (9) in a tiltable manner.
(19) A swash plate support structure for a variable displacement hydraulic motor equipped with a main body case (1), wherein a pair of trunnion shafts (16) project concentrically at diagonal positions on the outer periphery of the swash plate (8). And each trunnion shaft (16) is internally fitted and supported in a bearing block (17), and a pair of the bearing blocks (17) are detachably bolted to the inner bottom of the drive chamber (D). A swash plate support structure for a variable displacement hydraulic motor.