JPS6337497Y2 - - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a hydraulic motor with a brake.

Generally, hydraulic motors used in drive devices for crawler vehicles are equipped with a brake device to prevent the vehicle from moving due to gravity when the vehicle is stopped on a slope or the like. Usually, a brake device for this type of hydraulic motor includes a ring-shaped friction plate and a brake piston that are engaged with the output part of the hydraulic motor so as to rotate together with the output part, and when the hydraulic motor is driven, High-pressure fluid is applied to the brake piston to break contact between the friction plate provided at the output section of the hydraulic motor and the brake piston, and when the drive of the hydraulic motor is stopped and the supply of high-pressure fluid disappears, the brake is activated. An elastic body such as a spring with a built-in piston brakes and restrains the output portion of the hydraulic motor that is pressed against the friction plate. Conventionally, this friction plate and the output part (for example, a cylinder block) were connected by spline teeth formed on the inner periphery of the friction plate by broaching or slotter processing, and spline teeth formed on the outer periphery of the output part by hobbing. Spline connections were common.

However, in such a conventional brake device for a hydraulic motor, since the spline teeth between the output part of the hydraulic motor and the friction plate have normal machining accuracy, the spline teeth contact each other unevenly at the edges.
There was a drawback that these spline teeth were damaged. In addition, in view of these drawbacks, conventional methods have been used to improve the machining accuracy of spline teeth.
Alternatively, attempts have been made to increase the wall thickness of the spline teeth by increasing the module of the spline teeth. However, improving the machining accuracy of the spline teeth in the former case raises the problem of increased machining costs and the price of the hydraulic motor equipped with this brake device. Increasing the tooth depth and wall thickness of the spline will increase the radial dimension of the hydraulic motor equipped with this brake device when considering pressure resistance and durability. If the pitch diameter of the teeth is kept the same as that of a small module, there is a problem in that the cylinder hole provided near the spline teeth of the cylinder block, which is the output section, is deformed when the brake device is activated.

This invention was made by focusing on these conventional problems, and involves forming a plurality of arcuate grooves on the outer periphery of the cylinder block located between the cylinder holes, and engaging correspondingly with the arcuate grooves. The present invention aims to solve the above problem by providing a plurality of arcuate protrusions having a larger curvature than the arcuate grooves on the inner periphery of the friction plate.

This invention will be explained below based on the drawings.

1 and 2 are diagrams showing an embodiment of this invention.

First, to explain the configuration, 1 is a hydraulic motor with a brake, and 2 is a case as a fixed frame. A rear flange 3 is attached to one end of the case 2, and a rear flange 3 is provided with a pair of passages 4 passing through the interior of the case 2 for inlet and outlet of hydraulic oil.
An output shaft 5 projects from the other end wall. A cylinder block 6 is housed in the case 2 and rotates.The cylinder block 6 has a cylinder hole 7 in its end face, and is connected to the output shaft 5 by a spline at its center. Further, a plurality of arcuate grooves 8 are formed on the outer periphery of the cylinder block 6 so as to be located between the cylinder holes 7 and extend in the axial direction. The output shaft 5 and the cylinder block 6 together form an output section 9. Reference numeral 10 denotes an annular friction plate fitted on the outer periphery of the cylinder block 6 so as to be movable in the axial direction of the cylinder block 6. On the inner periphery of the friction plate 10, an arcuate groove 8 formed in the cylinder block 6 is provided. A plurality of arcuate protrusions 11 having a larger curvature are formed, and these arcuate protrusions 11 and the arcuate grooves 8 formed on the cylinder block 6 engage with each other, causing friction with the cylinder block 6. The plate 10 rotates together with the plate 10. The brake piston 12 is housed in the case 2 so as to be slidable in the axial direction.
A chamber 13 and a second chamber 14 are defined within the case 2.
A port 15 to which high pressure fluid is supplied to the first chamber 13
is provided and is connected to an external fluid source (not shown) by a passage 16. Further, a brake spring 17 is provided in the second chamber 14 and urges the brake piston 12 toward the friction plate 10 . A contact plate 19 whose outer periphery is splined to the case 2 is interposed between the brake piston 12 and the friction plate 10, and when the brake piston 12 presses the friction plate 10, the brake piston 12 presses against the friction plate 10.
This prevents it from being dragged and rotated. The friction plate 10, the brake piston 12, and the brake spring 17 constitute a brake mechanism 20 as a whole. 21 is a timing plate interposed between the cylinder block 6 and the rear flange 3, and 22 is a bearing for the output shaft 5. A piston 23 is fitted into a cylinder hole 7 provided in the cylinder block 6. The spring 24 is interposed between the cylinder block 6 and a thrust ball 25 splined to the output shaft 5.
The cylinder block 6 is urged toward the timing plate 21, and the piston shoe 26 press-fitted into the head of the piston 23 is urged against the swash plate 28 via the thrust ball 25 and the retainer plate 27. 29 is a bearing, and 30 is an oil seal.

Next, the action will be explained.

When the hydraulic motor 1 is currently in operation, high-pressure working fluid supplied from a fluid source (not shown) flows into the cylinder hole 7 through the pair of inlet/outlet passages 4 and pushes the piston 23. It is moving back and forth. As a result, the cylinder block 6 and the friction plate 10 that engages with the arcuate groove 8 of the cylinder block 6 via the arcuate protrusion 11 are rotated together.
On the other hand, the working fluid also flows into the first chamber 13 via the passage 16 and the port 15, and the brake piston 1
2 to the rear flange 3 side against the elastic force of the brake spring 17, and press the brake piston 1 against the elastic force of the brake spring 17.
2 and the friction plate 10 are separated. Therefore, the brake mechanism 20 does not operate, and the output section 9 continues to rotate.
Next, when the operation of the hydraulic motor 1 is stopped, the working fluid that flows into the cylinder hole 7 through the pair of inlet/outlet passages 4 and causes the piston 23 to reciprocate is The supply is stopped, and the first
The supply of the working fluid flowing into the chamber 13 and being applied to the brake piston 12 is also stopped. As a result, the rotational driving force of the cylinder block 6 and the friction plate 10 disappears, the brake mechanism 20 is activated, and the working fluid in the first chamber 13 flows out to a tank or the like connected to a fluid source (not shown). However, the brake piston 12 is urged toward the friction plate 10 by the brake spring 17, and presses the friction plate 10 against the case 2 via the contact plate 19. Therefore, the rotation of this friction plate 10 is restricted, and the rotation of this friction plate 10 is restricted.
The rotation of the cylinder block 6, which is engaged to rotate integrally with the arc-shaped protrusion 11 and the arc groove 8, is also prevented, and the output section 9 of the hydraulic motor 1 is locked to the case 2. becomes. In this case, since the smooth surfaces are engaged by the circular groove 8 and the circular protrusion having a larger curvature than the circular groove, local contact does not occur, and even if the hydraulic motor 1 Even if a high torque force is applied to the brake mechanism 20, the protrusion 11 or the arcuate groove 8 will not be damaged.

As explained above, according to this idea,
In a hydraulic motor with a brake, a plurality of arcuate grooves are arranged on the outer periphery between the cylinder holes of the cylinder block, and an arcuate protrusion having a larger curvature than the arcuate grooves is arranged on the inner periphery of the friction plate. Since the arcuate groove and the arcuate protrusion are engaged with each other, there is no loss of the protrusion, and high machining accuracy is not required, which eliminates the need for conventional expensive broaching and slotter machining. The advantage is that it can be manufactured using an inexpensive processing method such as casting, forging, or press processing instead of hobbing or hobbing.

Furthermore, since the cylinder holes and the arcuate grooves are arranged alternately on the cylinder block, it is possible to provide a deeper arcuate groove with a sufficiently small curvature without increasing the radial dimension of the cylinder block. It is possible to obtain a durable hydraulic motor with a brake that has low contact stress between the groove and the protrusion.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a hydraulic motor with a brake according to the present invention, and FIG. 2 is a cross-sectional view taken along A-A in FIG.
It is an arrow sectional view. DESCRIPTION OF SYMBOLS 1... Hydraulic motor with brake, 2... Case (fixed frame), 6... Cylinder block, 7... Cylinder hole, 8... Arc groove, 10... Friction plate, 11...
...Arc-shaped protrusion, 12...Brake piston, 2
0...Brake mechanism.

Claims (1)

[Scope of utility model registration request] A fixed frame, a rotating cylinder block housed in the fixed frame and having a plurality of cylinder holes arranged on its end face, and a rotating cylinder block attached to the outer periphery of the cylinder block, which rotates integrally with the cylinder block and is movable in the axial direction of the cylinder block. It has a fitted annular friction plate, and a brake piston that is housed in the fixed frame and is movable in the axial direction of the cylinder block, and that brakes the rotation of the friction plate by pressing the friction plate against the fixed frame. In the hydraulic motor with a brake, a plurality of arcuate grooves are arranged on the outer periphery of the cylinder block located between the cylinder holes, and an arcuate protrusion having a larger curvature than the arcuate grooves is provided on the inner periphery of the friction plate. A hydraulic motor with a brake, characterized in that the arcuate groove and the arcuate protrusion are engaged with each other.