JP2003336667A - Brake device for hydraulic motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of parts to reduce a space of a hydraulic motor by constituting a brake device for the hydraulic motor by a simple structure without using an acceleration mechanism. <P>SOLUTION: A motor case 3 is fitted into a brake member 4 with predetermined tightening allowance (it is in an interference fit state) and is in a state in which brake action is performed. Pressure oil is supplied into a sealed chamber 20 which is a part in which the brake member 4 and the motor case 3 are mutually fitted to release a braking condition. Consequently, the motor case 3 is deformed, the fitting condition is released, and the motor case 3 is rotated. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake device for a hydraulic motor. 2. Description of the Related Art In construction machines such as hydraulic excavators, FIG.
As shown in the figure, the motor case of the traveling hydraulic motor is connected to the crawler belt via a sprocket. When the traveling operation lever is operated, the motor case of the traveling hydraulic motor rotates to rotate the sprocket. Thus, the sprocket drives the crawler belt and the vehicle runs. When the work is stopped, the traveling operation lever is returned to the neutral position. In conjunction with the return of the traveling operation lever to the neutral position, the brake release pressure sent to the parking brake device of the traveling hydraulic motor decreases, the parking brake device operates, and the rotating shaft of the motor case is braked. As a result, the movement of the sprocket is locked, and accordingly the movement of the crawler belt is locked, so that the vehicle can be stopped even on a slope or the like. [0004] As a parking brake of a traveling hydraulic motor, an axis brake device including a plurality of disks and plates is used. The disk and the plate are alternately provided on the rotating shaft side and the fixed cylinder block side of the motor case, and the plate is pressed against the disk to bring about a brake effect. [0005] The conventional hydraulic motor is composed of a small-capacity motor section and a large-size reduction gear section, and has a complicated structure. For this reason, attempts have been made to reduce the size and cost by configuring the motor section so as to have a large capacity at low speed and high torque, and eliminating or reducing the speed reducer section. However, if a large-capacity motor is used, the parking brake must be increased in order to operate the parking brake when the traveling hydraulic motor is running at a low speed so that the brake is effective. As a result, in the case of a parking brake device consisting of discs and plates,
It is necessary to increase the number of plates, or to increase the size of the discs and plates, which increases the area of the parking brake device, and accordingly the area of the traveling hydraulic motor. Attempts have been made to reduce the size of the parking brake device. However, a parking brake device composed of a disk and a plate has a braking torque that depends on the allowable surface pressure of the disk and the plate and the coefficient of friction between the disk surface and the plate surface. There is a limit to miniaturization because it is determined. Therefore, Japanese Patent Application Laid-Open No. H11-141450 discloses that the rotation of a motor case is increased and transmitted to a rotating shaft.
An invention is described in which the increased rotation axis is braked by a parking brake device. According to the invention described in the above publication, the torque generated by the traveling hydraulic motor can be reduced by increasing the speed, so that the braking torque can be reduced and the parking brake can be reduced. The device can be downsized. However, in order to increase the speed, it is necessary to incorporate a complicated speed increasing mechanism such as a planetary gear mechanism into the traveling hydraulic motor, and the number of components increases and the area of the traveling hydraulic motor increases. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the number of components is reduced by reducing the number of parts by reducing the number of parts by using a simple structure for a brake device of a hydraulic motor without using a speed increasing mechanism. The problem is to make it smaller. The present invention provides a fixing member (4) connected to a vehicle body and a driving device (1).
4) and a rotating member (3) fitted to the fixed member, wherein a portion where the fixed member (4) and the rotating member (3) are fitted is sealed to form a sealed chamber ( 20) is formed, and the fixed member (4) or the rotating member (3) is deformed by supplying pressure oil to the sealed chamber (20), and the fixed member (4) and the rotating member (3) are deformed. The state in which is fitted is released. According to the present invention, as shown in FIG. 1, the rotating member (motor case) 3 includes a fixed member (brake member) 4.
Are fitted with a predetermined interference (in an interference fit state), and are in a state where a braking action is being performed. When releasing the state of the braking effect, the fixing member (brake member) 4 and the rotating member (motor case)
The pressurized oil is supplied to the sealed chamber 20, which is the portion where 3 is fitted. Thereby, the rotating member (motor case) 3 is deformed, the fitted state of both members is released, and the rotating member (motor case) 3 rotates. According to the present invention, the rotating member (motor case) 3 is fitted to the fixed member (brake member) 4 with a predetermined interference, and the fixed member (brake member) 4 and the rotating member (motor case) 3 are joined together. Since the fitting portion is sealed by, for example, sealing members 17 and 18 to form a sealed chamber 20, the brake device is configured.
The brake device can have a simple structure as compared with a conventional brake device including a plate. Furthermore, the rotating member (motor case) 3 and the fixed member (brake member) 4 are fitted (tight fit) without using a disk or plate having a low allowable surface pressure and a low coefficient of friction as in the prior art. Therefore, a large braking torque can be obtained with a small brake device, and there is no need to increase the speed by the speed increasing mechanism to reduce the torque of the hydraulic motor. As described above, according to the present invention, a brake device for a hydraulic motor can be configured with a simple structure without using a speed increasing mechanism, so that the number of parts is reduced and the field of the hydraulic motor is reduced. be able to. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a hydraulic motor brake device according to the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 shows a configuration of a hydraulic motor 1 according to a first embodiment, and is a cross-sectional view of the entire hydraulic motor 1. The embodiment assumes a traveling hydraulic motor 1 mounted on a construction machine such as a hydraulic excavator or a bulldozer. The hydraulic motor 1 is assumed to be a radial piston motor. The hydraulic motor 1 mainly includes a motor case 3 as a rotating member and a cylinder block 2 as a fixed member in which a piston portion is housed in the motor case 3. The cylinder block 2 is connected to the vehicle body via a bracket 15. Motor case 3 is connected to sprocket 14. The sprocket 14 drives a crawler belt (not shown). Inside the motor case 3, a fitting surface 3b for performing a braking action is formed. The motor case 3 is provided so as to be rotatable relative to the cylinder block 2 via a bearing 13, and when the braking operation is not performed, the shaft 3a
Rotate about the rotation center axis. The brake member 4 is fitted to the cylinder block 2 via a spline 10. The brake member 4 has a fitting surface 4b formed at a portion opposed to the fitting surface 3b so as to be fitted to the fitting surface 3b with a predetermined interference to make a "tight fit state". I have. The part where the brake member 4 and the motor case 3 are fitted on the fitting surfaces 4b, 3b is the seal member 1
Sealed by 7 and 18, a sealed chamber 20 is formed. The cylinder block 2 has a longitudinal axis 3
One end of the brake release pressure introducing member 16 is fitted so as to coincide with the direction a. The other end of the brake release pressure introducing member 16 is fitted to the brake member 4. The brake release pressure introduction member 16 has a brake release pressure introduction oil passage 6 for introducing the brake release pressure P1. A cylinder 31 is formed in the brake member 4, and a pressure-intensifying piston 30 is slidably provided in the cylinder 31. The pressure-intensifying piston 30 includes a large-diameter portion 30a and a small-diameter portion 30b. The large-diameter portion 30a faces the cylinder chamber 7 and the small-diameter portion 30b faces the cylinder chamber 8. The brake release pressure introducing oil passage 6 is connected to the cylinder chamber 7
, And the brake release pressure P1 acts on the pressure receiving surface on the large diameter portion 30a side of the pressure increasing piston 30. The hydraulic pressure P2 of the cylinder chamber 8 acts on the pressure receiving surface of the pressure increasing piston 30 on the small diameter portion 30b side. Here, assuming that the pressure receiving area on the large diameter portion 30a side of the pressure increasing piston 30 is S1 and the pressure receiving area on the small diameter portion 30b side is S2, the oil pressure P2 of the cylinder chamber 8 on the small diameter portion 30b side is P2
= (S1 / S2) · P1, and the brake release pressure P1 is increased to P2 in proportion to the pressure receiving area ratio S1 / S2. The cylinder chamber 7 communicates with the sealing chamber 20 via an oil passage 8. Therefore, when the brake release pressure P1 is introduced into the brake release pressure introduction oil passage 6, the brake release pressure P1 is increased to the brake release pressure P2 by the pressure-intensifying piston 30 and is introduced into the sealed chamber 20. Thereby, the motor case 3
A stress corresponding to the brake release pressure P2 acts on the fitting surface 3b of the motor case 3, and the fitting surface 3 of the motor case 3 formed in an annular shape.
b is deformed so as to bulge outward as shown by a dashed line. Thereby, the fitted state of the motor case 3 and the brake member 4 is released, and the motor case 3 becomes rotatable. Note that the brake release pressure P1 is
Is increased to P2 by the fitting surface 3b of the motor case 3.
If the force required to deform the motor case 3 can be obtained without increasing the pressure, the pressure increasing piston 30 may be omitted. Next, the operation of the first embodiment shown in FIG. 1 will be described. When a travel control lever (not shown) is operated, the travel control valve is opened from the neutral position, and in conjunction with this, the brake release pressure P1 is introduced into the brake release pressure introduction oil passage 6. The brake release pressure P1 acts on the pressure receiving surface on the large diameter portion 30a side of the pressure-intensifying piston 30 via the brake release pressure introduction oil passage 6 and the cylinder chamber 7. As a result, the hydraulic pressure acting on the small-diameter portion 30b side of the pressure-intensifying piston 30 increases to P2. The increased brake release pressure P2 is applied to the cylinder chamber 8,
It is introduced into the sealed chamber 20 via the oil passage 9. As a result, a stress corresponding to the brake release pressure P2 acts on the fitting surface 3b of the motor case 3 so that the fitting surface 3b of the motor case 3 formed in an annular shape bulges outward as shown by a dashed line. To be deformed. Thereby, the fitted state of the motor case 3 and the brake member 4 is released, and the motor case 3 rotates relatively to the cylinder block 2. When the motor case 3 rotates, the sprocket 14 connected thereto rotates to drive the crawler belt. The vehicle runs by driving the crawler belt. As the operation amount of the travel operation lever increases, the opening area of the travel operation valve increases, the flow rate of the pressure oil flowing from the hydraulic pump to the pressure oil inflow port of the hydraulic motor 1 increases, and the rotation of the motor case 3 Speed increases. When the rotation speed of the motor case 3 increases, the traveling speed of the vehicle increases. When the traveling operation lever is returned to the neutral position, the opening of the traveling operation valve is closed, and in conjunction with this, the brake release pressure P1 decreases. When the brake release pressure P1 decreases, the brake release pressure P2 introduced into the sealed chamber 20 also decreases, so that the stress acting on the fitting surface 3b of the motor case 3 decreases, and the fitting surface 3b of the motor case 3 and the brake member 4 The fitting surface 4b is in a fitted state, and a braking action is performed. As a result, the motor case 3 is
Through the cylinder block 2. When the movement of the motor case 3 is locked, the movement of the sprocket 14 connected thereto is also locked, the movement of the crawler belt is locked, and the movement of the vehicle stops. However, if the brake release pressure P1 becomes zero at the same time when the traveling operation lever is returned to the neutral position, the movement of the motor case 3 is suddenly locked even though the hydraulic motor 1 is rotating due to inertia. There is a problem that the state is changed. Therefore, in this embodiment, the flow rate of the pressure oil introduced into the brake release pressure introducing oil passage 6 is adjusted by providing a throttle valve or the like, and the brake release is performed after the traveling operation lever is returned to the neutral position. The time until the pressure P1 becomes zero is delayed so that when the rotation of the hydraulic motor 1 stops, a braking action is performed to lock the movement of the motor case 3. According to the first embodiment described above, the motor case 3 is fitted to the brake member 4 with a predetermined interference, and the portion where the brake member 4 and the motor case 3 are fitted is sealed with the sealing member 17. , 18 to form a sealed chamber 20, thereby forming a brake device.
The brake device can have a simple structure as compared with a conventional brake device including a disk and a plate. Further, unlike the conventional case, the motor case 3 and the brake member 4 are fitted to each other without using disks and plates having a low allowable surface pressure and a low coefficient of friction (tight fit).
As a result, a large braking torque can be obtained with a small brake device,
There is no need to increase the speed by the speed increasing mechanism to reduce the torque of the hydraulic motor. As described above, according to the first embodiment, the brake device for the hydraulic motor can be configured with a simple structure without using a speed increasing mechanism. Can be reduced. Various modifications can be made to the first embodiment described with reference to FIG. In the following description, the components having the same reference numerals as those in FIG. Second Embodiment FIG. 2 is a sectional view showing the structure of a hydraulic motor 1 according to a second embodiment, similarly to FIG. The point that the brake member 4 is fitted to the cylinder block 2 via the spline 10 is the same as in FIG. 1, but in FIG. 2, the brake member 4 is formed in an annular shape. Although the fitting surface 3b of the motor case 3 is fitted to the fitting surface 4b of the brake member 4, it is the same as in FIG. 1, but in FIG. The inner peripheral fitting surface 4b of the brake member 4 is fitted to the fitting surface 3b of the lever shaft 3c. A hydraulic circuit for increasing the brake release pressure P1 and introducing the brake release pressure P2 increased to the sealed chamber 20 is the same as FIG. 1, but in FIG. 2, this hydraulic circuit is It is provided on the shaft portion 3c of the motor case 3. In the configuration shown in FIG. 2, when the traveling operation lever (not shown) is operated, the traveling operation valve is opened from the neutral position, and in conjunction with this, the brake release pressure P1 is increased and the brake release pressure introducing oil passage 6 is opened. Will be introduced. Brake release pressure P1
Acts on the pressure receiving surface on the large-diameter portion 30a side of the pressure-intensifying piston 30 via the brake release pressure introducing oil passage 6 and the cylinder chamber 7. Thereby, the hydraulic pressure acting on the small diameter portion 30b side of the pressure increasing piston 30 increases to P2. The increased brake release pressure P2 is introduced into the sealing chamber 20 via the cylinder chamber 8 and the oil passage 9. As a result, a stress corresponding to the brake release pressure P2 acts on the fitting surface 4b of the brake member 4 so that the fitting surface 4b of the annularly formed brake member 4 bulges outward as indicated by a dashed line. To be deformed. Thus, the fitted state of the shaft portion 3c of the motor case 3 and the brake member 4 is released, and the motor case 3 rotates relatively to the cylinder block 2. When the motor case 3 rotates, the sprocket 14 connected thereto rotates to drive the crawler belt. The vehicle runs by driving the crawler belt. As the operation amount of the travel operation lever increases, the opening area of the travel operation valve increases, the flow rate of the pressure oil flowing from the hydraulic pump to the pressure oil inflow port of the hydraulic motor 1 increases, and the rotation of the motor case 3 Speed increases. When the rotation speed of the motor case 3 increases, the traveling speed of the vehicle increases. When the traveling operation lever is returned to the neutral position, the opening of the traveling operation valve is closed, and in conjunction with this, the brake release pressure P1 decreases. When the brake release pressure P1 decreases, the brake release pressure P2 introduced into the sealed chamber 20 also decreases, so that the stress acting on the fitting surface 4b of the brake member 4 decreases, and the fitting surface 3 of the shaft portion 3c of the motor case 3 decreases.
b and the fitting surface 4b of the brake member 4 are in a fitted state, and a braking action is performed. As a result, the motor case 3 is locked with respect to the cylinder block 2 via the brake member 4. When the movement of the motor case 3 is locked, the movement of the sprocket 14 connected thereto is also locked, the movement of the crawler belt is locked, and the movement of the vehicle stops. In the above-described embodiment, the brake member 4 is fitted to the cylinder block 2 via the spline 10, and the brake member 4 and the motor case 3 are fitted. An embodiment in which 3 is directly fitted is also possible. Although the above embodiment has been described assuming a brake device for a traveling hydraulic motor, the present invention may be applied to a brake device for a turning hydraulic motor that stops the movement of the upper turning body. The present invention can be applied not only to the use for stopping the movement of the traveling body and the revolving body, but also to any use such as the use for stopping the movement of the working machine.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a configuration of a first embodiment, and is a cross-sectional view of the entire hydraulic motor. FIG. 2 is a diagram showing a configuration of a second embodiment, and is a cross-sectional view of the entire hydraulic motor. FIG. 3 is a diagram showing a conventional technique. [Description of Signs] 1 Hydraulic motor 3 Motor case (rotating member) 4 Brake member (fixing member) 20 Sealed chamber

Claims (1)

Claims: 1. A fixing member (4) connected to a vehicle body.
And a rotating member (3) connected to the driving device (14) and fitted to the fixing member, wherein a portion where the fixing member (4) and the rotating member (3) are fitted is sealed. Forming a sealed chamber (20) by supplying pressure oil to the sealed chamber (20) to deform the fixed member (4) or the rotating member (3), A brake device for a hydraulic motor, wherein a state in which the rotating member (3) is fitted is released.