JP3846758B2 - Braking device for radial piston motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a brake device for a radial piston motor used for rotating a drive sprocket of a crawler type traveling body of a construction machine.
[0002]
[Prior art]
As a radial piston motor, one that directly rotates a motor case without using a reduction gear described in US Pat. No. 5,115,890 is known.
[0003]
Specifically, the motor case is rotatably mounted on a cylindrical cylinder block, a plurality of cylinders are radially formed on the cylinder block, and the cylinder piston is pressed against the cam surface on the inner surface of the motor case. A high pressure oil is sequentially supplied to the cylinder chamber by a switching valve provided inside the block, and the roller is pressed against the cam surface to rotate the motor case.
[0004]
As a brake device for the above-mentioned radial piston motor, a brake disk provided on a cylinder block and a motor case, a brake piston, and a spring are provided, and the brake piston is pressed by the spring to press the brake disk into a braking state. Thus, it is known that the brake piston is moved against the spring and the brake disk is released to be in a non-braking state.
[0005]
[Problems to be solved by the invention]
The braking torque of the brake device of such a radial piston motor is equal to or greater than the output torque of the motor case (that is, the output torque of the motor), and the braking torque is large. For this reason, the brake device is large and the entire radial piston motor is large, and the mounting area of the radial piston motor is large. Therefore, when the radial piston motor is mounted on a crawler type traveling body of a construction machine and the sprocket is driven by the radial piston motor, the mounting area of the radial piston motor is small. It becomes difficult.
[0006]
Accordingly, an object of the present invention is to provide a brake device for a radial piston motor that can solve the above-described problems.
[0007]
[Means for solving the problems and effects]
1st invention has the cylinder block 1, the motor case 3 which has the cam 12 for rotation in the inner peripheral surface, was rotatably attached to the outer peripheral surface of the cylinder block 1, and the said cylinder block 1 was provided radially, The rotation roller 11 provided on the piston 7 is provided with a plurality of cylinder portions 10 facing the rotation cam 12 and the cylinder block 1, and a plurality of chambers 8 in the cylinder portion 10 communicate with a hydraulic source and a tank. Switching valve 24,
High pressure oil is supplied to some chambers 8 of the plurality of cylinder portions 10, the remaining chambers 8 of the cylinder portions 10 communicate with the tank, and some of the plurality of rotation rollers 11 are pressed against the rotation cam 12. In the radial piston motor configured to rotate the motor case 3,
A radial piston motor having a speed increasing mechanism 41 for speeding up rotation of the motor case 3 and a brake device provided between the speed increasing rotating portion of the speed increasing mechanism 41 and the cylinder block 1 is provided. Brake device.
[0008]
According to the first invention, the rotation of the motor case 3 that rotates at a low speed is accelerated by the speed increasing mechanism 41 and the speed increasing rotation portion is braked by the brake device, so that the braking torque of the brake device is the output of the motor case 3. It becomes smaller than torque.
As a result, since the brake device is small and the entire radial piston motor is small, the mounting area of the radial piston motor is small.
Therefore, the radial pistol motor can be easily attached to the crawler type traveling body of the construction machine for driving the sprocket.
[0009]
According to a second invention, in the first invention, a ring gear 46, a planetary gear 48 provided on the carrier 47, and a sun gear 49 provided on a rotating shaft 40 rotatably supported on the carrier 47 are provided. By fixing to the case 3 and fixing the carrier 47 to the cylinder block 1, a planetary gear type speed increasing mechanism 41 is obtained.
A brake device for a radial piston motor, in which the rotary shaft 40 and a brake disc 42 attached to the cylinder block 1 and a brake piston 44 that presses and separates the brake disc 42 are used as a brake device.
[0010]
According to the second invention, since the planetary gear type speed increasing mechanism 41 is used, the rotation of the motor case 3 is further increased to a higher speed, and the speed increasing mechanism 41 is compact.
As a result, the braking torque of the brake device is further reduced, the radial piston motor is further reduced in size, and the speed increasing mechanism 41 can be easily mounted across the motor case 3 and the cylinder block 1.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, a motor case 3 is rotatably attached to the outer peripheral surface of the cylinder block 1 via a bearing 2. A mounting plate 4 is attached to one end face 1a of the cylinder block 1 with bolts 5, and the mounting plate 4 is connected to a track frame of a crawler type traveling body.
[0012]
A plurality of cylinder holes 6 are radially formed at equal intervals in the circumferential direction in the axially intermediate portion of the cylinder block 1. A piston 7 is fitted in each cylinder hole 6 to form a chamber 8 and a small-diameter extension chamber 9, thereby forming a cylinder portion 10.
[0013]
Each piston 7 is provided with a rotation roller 11, and the rotation roller 11 contacts a rotation cam 12 formed on the inner peripheral surface of the motor case 3, and the rotation cam 12 is as shown in FIG. 2. It has a wavy cam surface in which a plurality of convex portions and a plurality of concave portions are smoothly continuous.
[0014]
The cylinder block 1 is provided with the same number of spools 20 as the cylinder portion 10 in a radial manner at equal intervals in the circumferential direction. Each spool 20 includes a roller 21, and a spring 22 presses the roller 21 against a spool switching cam 23 of the motor case 3 to constitute a switching valve 24.
[0015]
As shown in FIG. 3, the spool switching cam 23 has a cam surface having a plurality of convex portions and concave portions alternately at a predetermined angle like the rotating cam 12, and the roller 21 is in contact with the convex portion. 1, the first port 25 and the second port 26 are communicated, and the second port 26 and the third port 27 are blocked. When the roller 21 comes into contact with the recess, the second port 26 and the third port 27 are communicated with each other as shown in the lower part of FIG. The first port 25 communicates with the first main port 29 through the first annular oil hole 28, the second port 26 communicates with the chamber 8, and the third port 27 communicates with the second main port 31 through the second annular oil hole 30. Communicate. The small-diameter extension chamber 9 is always supplied with low-pressure oil. A sprocket 32 for driving the crawler belt of the crawler type traveling body is attached to the motor case 3.
[0016]
Next, the operation will be described.
High pressure oil is supplied to the first main port 29, and the second main port 31 communicates with the tank. In the case shown in FIGS. 2 and 3, the rollers 21 of the three spools 20 come into contact with the convex portions of the spool switching cam 23, and the high pressure oil flows into the chambers 8 of the three cylinders 10. 21 is in contact with the concave portion of the spool switching cam 23 and the chamber 8 of the two cylinder portions 10 communicates with the tank.
[0017]
As a result, the three rotation rollers 10 are pressed against the rotation cam 12, and the motor case 3 is rotated in the direction of arrow a. When the motor case 3 rotates by a predetermined angle in the direction of arrow a, the roller 21 of one spool 20 rotates from the convex portion of the spool switching cam 23 to the concave portion, and the roller 21 of one spool 20 rotates into the concave portion of the spool switching cam 23. The motor case 3 rotates in the direction of arrow a.
[0018]
In this way, the high pressure oil is sequentially supplied to the chamber 8 of the cylinder portion 10 and communicated with the tank, so that the motor case 3 rotates smoothly.
[0019]
Further, when the low-pressure oil is constantly supplied to the small-diameter extension chamber 9 and the chamber 8 communicates with the tank, the extension force acts on the piston 7, so that the rotation roller 11 is separated from the rotation cam 12. Since the rotation roller 11 does not collide with the cam of the rotation cam 12 when the high pressure oil is applied to the chamber 8, the cylinder portion 10 can be prevented from being damaged.
[0020]
Next, the brake device will be described.
A rotating shaft 40 is rotatably supported on the shaft center of the other end of the cylinder block 1, and the rotating shaft 40 is connected to the motor case 3 by a speed increasing mechanism 41. The rotating shaft 40 serves as a speed increasing rotation portion of the speed increasing mechanism 41.
[0021]
A brake disk 42 is provided on the rotary shaft 40 and the cylinder block 1 so as not to rotate alternately by spline fitting or the like. The brake disk 42 is pressure-bonded by a brake piston 44 pressed by a spring 43 such as a disc spring. When the rotary shaft 40 is fixed to the cylinder block 1 for braking, the pressure oil is supplied to the pressure receiving chamber 45 and the brake piston 44 is moved against the spring 43, so that the brake disk 42 is separated and is not braked. This constitutes a brake device.
[0022]
The speed increasing mechanism 41 is fixed to the rotating shaft 40, a ring gear 46 fixed to the inner surface of the motor case 3, a carrier 47 fixed to the cylinder block 1, a planetary gear 48 rotatably supported on the carrier 47, and the rotating shaft 40. A planetary gear type speed increasing mechanism including a sun gear 49 is provided. The rotary shaft 40 is rotatably supported on the carrier 47.
[0023]
As shown in FIGS. 4 and 5, the carrier 47 includes one side plate 50 and another side plate 51, and one central side circular recess 52 and a plurality of outer peripheral side circular recesses 53 are provided on the opposing surfaces of the one side plate 50 and the other side plate 51. Are formed continuously, and a part of the outer circular recess 53 is open to the outer peripheral surface, and a bearing circular recess 54 is formed at the center of the outer circular recess 53, respectively. is there. A rotary shaft circular recess 55 is formed at the center of the center side circular recess 52 of the one side plate 50, and a hole 56 is formed at the center of the center side circular recess 52 of the other side plate 50.
[0024]
The one side plate 50 and the other side plate 51 are connected in contact with each other, and a sun gear 49 is rotatably accommodated between the opposed center side circular recesses 52, and a planetary gear 48 is placed in each of the opposing bearing circular recesses 54. The planetary gear 48 is rotatably supported between the opposed circular recesses 53 that are rotatably supported by the bearings 57. The rotary shaft 40 passes through the hole 56 of the other side plate 51 and is rotatably supported by a bearing 58 in the rotary shaft circular recess 55 of the one side plate 50.
[0025]
The carrier 47 is fixed to the other end surface 1 b of the cylinder block 1 with a bolt 59. The carrier 47 serves as a spring receiver for the spring 43.
[0026]
The speed increasing mechanism 41 may be a gear type in which a plurality of gears are engaged.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a radial piston motor showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA of FIG.
FIG. 3 is an explanatory diagram of a spool switching cam.
4 is a cross-sectional view taken along the line BB in FIG.
FIG. 5 is an exploded perspective view of a carrier.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Cylinder block 3 ... Motor case 7 ... Piston 8 ... Chamber 10 ... Cylinder part 11 ... Rotating roller 12 ... Rotating cam 24 ... Switching valve 40 ... Rotating shaft (acceleration rotating part)
41 ... Speed increasing mechanism 42 ... Brake disc 43 ... Spring 44 ... Brake piston 46 ... Ring gear 47 ... Carrier 48 ... Planetary gear 49 ... Sun gear 50 ... One side plate 51 ... Other side plate

Claims (2)

A cylinder block (1), a motor case (3) having a rotation cam (12) on the inner peripheral surface and rotatably mounted on the outer peripheral surface of the cylinder block (1), and a radial shape on the cylinder block (1) The rotation roller (11) provided on the piston (7) is provided on the cylinder block (1), the cylinder block (10) facing the rotation cam (12), and the cylinder block (1). A plurality of switching valves (24) communicating the chamber (8) of the section (10) with the hydraulic power source and the tank;
The high pressure oil is supplied to some chambers (8) of the plurality of cylinder portions (10), and the remaining chambers (8) of the cylinder portions (10) communicate with the tanks to determine how many of the plurality of rotation rollers (11). In the radial piston motor configured to rotate the motor case (3) by being pressed against the rotating cam (12),
A speed increasing mechanism 41 for speeding up the rotation of the motor case (3) is provided, and a brake device is provided between the speed increasing rotating portion of the speed increasing mechanism (41) and the cylinder block (1). A brake device for a radial piston motor. A ring gear (46); a planetary gear (48) provided on the carrier (47); and a sun gear (49) provided on a rotating shaft (40) rotatably supported on the carrier (47). Is fixed to the motor case (3), and the carrier (47) is fixed to the cylinder block (1) to form a planetary gear type speed increasing mechanism (41).
The radial piston according to claim 1, wherein the rotary shaft (40), a brake disk (42) attached to the cylinder block (1), and a brake piston (44) that presses and separates the brake disk (42) are used as a brake device. Motor brake device.

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