A hydraulic motor integrating service brake and parking brake

Abstract

The present invention discloses a hydraulic motor integrating driving brake and parking brake, comprising a stator, a rotor assembly, a motor front cover and a motor rear cover. A multifunctional braking device is arranged in the motor front cover. The multifunctional braking device comprises a friction plate assembly, a driving brake control assembly and a parking brake control assembly. The driving brake control assembly comprises a driving brake control oil port, a driving brake oil chamber and a driving brake piston. The parking brake control assembly comprises a parking brake oil port, a parking brake oil chamber, a parking brake piston and a disc spring. The friction plate assembly is installed in the brake chamber. A movable first pressure plate and a movable second pressure plate are respectively arranged on both sides of the friction plate assembly. The driving brake piston is connected to the first pressure plate. When the disc spring is not under force, the second pressure plate is pressed. The advantage is that the driving brake function and the driving brake function are integrated and arranged in the motor front cover, and the volume of the hydraulic motor will not be increased extra.

Description

Technical Field

[0001] The invention relates to the field of hydraulic motors, and in particular to a hydraulic motor integrating service brake and parking brake. Background Art

[0002] In the power system of heavy-duty vehicles, hydraulic motors are core components, and their performance and reliability are directly related to the operating efficiency and safety of the entire vehicle. With the continuous advancement of engineering technology, higher requirements are placed on the braking performance of hydraulic motors, aiming to achieve more precise braking control, higher thermal stability and lower maintenance costs.

[0003] Traditional hydraulic motor brake systems mostly use a combination of drum brakes and friction plate brakes to achieve the dual functions of driving brakes and parking brakes. Due to its structural characteristics, the drum brake is placed in front of the rotor and stator, responsible for providing the necessary braking torque during driving. However, this dry braking method is prone to generate a lot of heat due to friction during long-term or high-intensity braking, which not only reduces braking efficiency, but may also cause sparks, increase fire risks, and pose a threat to vehicle and personnel safety.

[0004] On the other hand, the friction plate brake is arranged on the rear cover of the motor and is specifically used for parking brakes. Although it alleviates the thermal load problem of driving brakes to a certain extent, its layout brings new challenges. Since the rear cover of the hydraulic motor integrates a complex hydraulic oil circuit system, the installation of the friction plate brake requires additional space, which not only increases the design difficulty and manufacturing cost of the rear cover, but also inevitably leads to the expansion of the entire motor volume, which has an adverse effect on the space layout and weight optimization of the vehicle. In addition, the use of two different types of brakes also increases the overall complexity of the system and the maintenance cost. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a hydraulic motor integrating driving brake and parking brake. The present invention integrates the parking brake function and the driving brake function into one component without increasing the volume of the hydraulic motor.

[0006] The technical solution adopted by the present invention to solve the above technical problems is: a hydraulic motor integrating driving brake and parking brake, including a stator, a rotor assembly, a motor front cover and a motor rear cover, the rotor assembly is connected to the output shaft, a distribution shaft is arranged in the motor rear cover, the output shaft passes through the motor front cover to connect to the outside world, a multifunctional braking device is arranged in the motor front cover, the multifunctional braking device includes a friction plate assembly, a driving brake control assembly and a parking brake control assembly, the friction plate assembly includes a plurality of dynamic friction plates and a plurality of static friction plates, the driving brake control assembly includes a driving brake control oil port, a driving brake oil chamber and a driving brake piston, the parking brake control assembly includes a parking brake oil port, a parking brake oil chamber, a parking brake piston and a disc spring, the friction plate assembly is installed in the brake cavity, the friction plate assembly A movable first pressure plate and a movable second pressure plate are respectively arranged on both sides. The service brake piston is connected to the first pressure plate, and the disc spring squeezes the second pressure plate when no force is applied; when hydraulic oil is rushed into the service brake control oil port, the service brake piston squeezes the first pressure plate, so that the friction plate assembly generates a braking torque. The greater the pressure of the hydraulic oil rushed in, the greater the braking torque is, which has a service braking effect; when the service brake control oil port stops rushing into the hydraulic oil and the parking brake oil port stops rushing into the hydraulic oil, the parking brake piston squeezes the disc spring, so that the disc spring no longer squeezes the second pressure plate, and the hydraulic motor is not subject to the braking torque and operates normally; when the service brake control oil port stops rushing into the hydraulic oil and the parking brake oil port stops rushing into the hydraulic oil, the disc spring squeezes the second pressure plate, so that the friction plate assembly generates a braking torque, which has a parking brake effect.

[0007] A further preselected solution of the present invention is that the parking brake piston and the friction plate assembly are arranged on the front side of the disc spring. When the parking brake piston is squeezed by the hydraulic oil and moves toward the rear side, the disc spring is squeezed and the disc spring gradually reduces the squeezing force on the friction plate assembly.

[0008] A further preselected scheme of the present invention is: the motor front cover includes a connecting cylinder body and a brake cylinder body, the multifunctional braking device is arranged in a cavity formed by the connecting cylinder body and the brake cylinder body, the connecting cylinder body is arranged between the brake cylinder body and the stator, a spring groove is arranged in the connecting cylinder body, a disc spring is installed in the spring groove, the inner end of the disc spring and the spring groove contact each other, the outer end of the disc spring is aligned with the contact point of the parking brake piston, and the middle part of the disc spring is aligned with the contact point of the second pressure plate.

[0009] A further preselected solution of the present invention is: an inner end of the second pressure plate is provided with an inner hole structure, and a protrusion is provided at the lower end of the spring groove, and the protrusion enters or moves out of the inner hole structure as the disc spring and the second pressure plate are squeezed.

[0010] A further preselected solution of the present invention is that an oil drain pipe is provided in the spring groove so that the pressure at both ends of the friction plate assembly is substantially the same.

[0011] A further preselected solution of the present invention is that a flushing oil port is provided in the brake cavity, and hydraulic oil enters from the flushing oil port and passes through the friction plate assembly to take away heat and iron filings, and is finally discharged from the oil drain port of the motor.

[0012] A further preselected solution of the present invention is that an avoidance groove is provided at the inner end of the spring groove, and when the disc spring is squeezed again, the inner end of the disc spring moves toward the avoidance groove, and the diameter of the avoidance groove is smaller than the inner end diameter of the disc spring.

[0013] A further preselected solution of the present invention is that the outer end of the second pressure plate and the disc spring squeeze each other, and an extrusion protrusion is provided at the outer end of the second pressure plate, which prevents the second pressure plate and the disc spring from fitting together to form an adsorption force during extrusion.

[0014] A further preselected scheme of the present invention is: a first concave cavity and a second concave cavity are arranged on the inner wall of the brake cylinder body, the first concave cavity is arranged on the inner side of the second concave cavity, a partition wall is arranged between the first concave cavity and the second concave cavity, the inner end of the spring groove is aligned with the first concave cavity, and the outer end of the spring groove is aligned with the second concave cavity, the first concave cavity includes a service brake oil cavity, an active cavity of a service brake piston and a brake cavity, and the second concave cavity includes a parking brake oil cavity and an active cavity of a parking brake piston.

[0015] A further preselected solution of the present invention is that a plurality of annular grooves and a plurality of radial grooves are arranged on the static friction plate, and the annular grooves and the radial grooves are connected.

[0016] Compared with the prior art, the present invention sets a multifunctional braking device in the motor front cover, realizes parking braking and driving braking at the same time, transforms the internal structure of the motor front cover, and utilizes the space of the motor front cover itself to realize the braking effect, without increasing the volume of the hydraulic motor. The multifunctional braking device integrates the two braking functions, greatly reducing the volume of the braking device. Therefore, the advantages of the present invention are: on the one hand, it utilizes the integrated processing of the two braking functions to reduce the volume of the braking device, and on the other hand, it fully utilizes the simple structure of the motor front cover, and installs the braking device in the motor front cover to realize braking, and finally realizes the addition of driving braking and parking braking functions without increasing the extra volume of the motor. At the same time, because the braking device is closer to the output end of the output shaft, it can provide better braking internal force and improve the stress condition of the internal parts of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the hydraulic motor of the present invention;

[0018] Figure 2 It is a schematic diagram of the structure of a traditional hydraulic motor;

[0019] Figure 3It is a structural schematic diagram when there is no hydraulic oil in the service brake control component and the parking brake control component;

[0020] Figure 4 for Figure 3 The enlarged view of point A in the middle;

[0021] Figure 5 It is a structural schematic diagram when there is no hydraulic oil in the service brake control component and there is hydraulic oil in the parking brake control component;

[0022] Figure 6 for Figure 5 The enlarged view of point B in the middle;

[0023] Figure 7 It is a schematic diagram of the structure when there is hydraulic oil in both the service brake control component and the parking brake control component;

[0024] Figure 8 An exploded view of the motor front cover and the multifunctional brake device of the present invention;

[0025] Fig. 9 is a three-dimensional diagram of the static friction plate;

[0026] Fig.10 This is a schematic diagram of the structure of the hydraulic motor after removing the service brake control component and the parking brake control component.

[0027] Reference numerals:

[0028] Stator 1; rotor assembly 2; motor front cover 3; motor rear cover 4; output shaft 5; friction plate assembly 6; service brake control assembly 7; parking brake control assembly 8; dynamic friction plate 9; static friction plate 10; service brake control oil port 11; service brake oil chamber 12; service brake piston 13; parking brake oil port 14; parking brake oil chamber 15; parking brake piston 16; disc spring 17; brake chamber 18; first pressure plate 19; second pressure plate 20; connecting cylinder 21; brake cylinder 22; spring groove 23; inner hole structure 24; protrusion 25; flushing oil port 26; avoidance groove 27; extrusion protrusion 28; annular groove 31; radial groove 32; oil drain pipe 33; first concave cavity 41; second concave cavity 42; partition wall 43. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings.

[0030] like Figure 1-Figure 10As shown, a hydraulic motor integrating driving brake and parking brake includes parking brake function and driving brake function. The parking brake function is used to provide braking torque for the vehicle when it is stopped, and the driving brake function is used to provide braking torque for the vehicle when it is driving. The hydraulic motor includes a stator 1, a rotor assembly 2, a motor front cover 3 and a motor rear cover 4, the rotor assembly 2 is connected to the output shaft 5, a distribution shaft is arranged in the motor rear cover 4, and a plurality of hydraulic oil channels are arranged in the distribution shaft. The motor front cover described in this article is a cover body close to the output end of the output shaft, and the motor rear cover is a cover body away from the output end of the output shaft. When the traditional brake is placed at the rear end of the motor, the number of parts is increased, resulting in the complexity of the motor structure. The load torque acts on the motor from the output end of the output shaft of the output module. If the brake is placed at the rear end of the motor, the braking torque is generated at the rear end. The load torque is balanced with the braking torque. From the front end of the motor to the rear end of the motor, the length involved in the middle is large, and the parts involved include: brake cylinder, output shaft 5, motor rear cover 4, stator 1, and there are many parts. This increases the internal force of the motor during braking and the strength requirements of the parts. The driving braking torque required by the vehicle is much greater than the parking braking torque, generally twice the parking braking torque. Therefore, in order to improve the force environment inside the motor, the traditional solution is: in order to be closer to the load torque source, the driving brake is placed at the front end of the motor rather than at the rear end of the motor; and the parking brake is placed at the front end of the motor, which can improve the force environment inside the motor, increase the service life of the motor, and reduce the strength requirements of the parts involved.

[0031] A multifunctional braking device is arranged in the motor front cover 3, and the multifunctional braking device includes a friction plate assembly 6, a driving brake control assembly 7 and a parking brake control assembly 8. The friction plate assembly 6 includes a plurality of dynamic friction plates 9 and a plurality of static friction plates 10. The plurality of dynamic friction plates 9 and the plurality of static friction plates 10 are arranged alternately. The dynamic friction plates 9 and the output shaft 5 are fixed to each other. The dynamic friction plates 9 and the static friction plates 10 squeeze each other to generate a braking torque, so that the output shaft 5 is subjected to a braking torque.

[0032] The service brake control assembly 7 includes a service brake control oil port 11, a service brake oil chamber 12 and a service brake piston 13. The parking brake control assembly 8 includes a parking brake oil port 14, a parking brake oil chamber 15, a parking brake piston 16 and a disc spring 17. The friction plate assembly 6 is installed in the brake chamber 18. A movable first pressure plate 19 and a movable second pressure plate 20 are respectively arranged on both sides of the friction plate assembly 6. The service brake piston 13 is connected to the first pressure plate 19. When the service brake piston 13 is subjected to hydraulic pressure, it will push the first pressure plate 19 to move to the rear side. As the hydraulic pressure increases, the service braking torque gradually increases. When the disc spring 17 is not subjected to force or pushed by the parking brake piston 16, it squeezes the second pressure plate 20 to form the maximum parking brake torque. After the disc spring 17 is subjected to the thrust of the parking brake piston 16, as the force it is subjected to increases, the force on the second pressure plate 20 gradually decreases, and the parking brake torque gradually decreases. The following are the three limit states during operation:

[0033] Status 1: Figure 7 As shown, when hydraulic oil is rushed into the service brake control oil port 11 and the parking brake oil port 14, the service brake piston 13 squeezes the first pressure plate 19, causing the friction plate assembly 6 to generate a braking torque to achieve a service braking effect. At this time, the service braking torque increases with the increase of the hydraulic oil pressure of the service brake control oil port 11.

[0034] Status 2: Figure 5 As shown, when the service brake control oil port 11 stops pumping hydraulic oil and the parking brake oil port 14 pumps hydraulic oil, the parking brake piston 16 squeezes the disc spring 17, so that the disc spring 17 no longer squeezes the second pressure plate 20, and the hydraulic motor operates normally. At this time, the vehicle is completely free from braking torque and can operate freely and normally.

[0035] State three: Figure 3 As shown, when the service brake control oil port 11 stops pumping hydraulic oil and the parking brake oil port 14 stops pumping hydraulic oil, the disc spring 17 squeezes the second pressure plate 20, so that the friction plate assembly 6 generates a braking torque, which has a parking brake effect. At this time, the parking brake torque increases as the oil pressure of the parking brake oil port 14 decreases. After the hydraulic pressure completely disappears, the parking brake torque is the largest.

[0036] The parking brake piston 16 and the friction plate assembly 6 are arranged on the front side of the disc spring 17. When the parking brake piston 16 is squeezed by the hydraulic oil and moves toward the rear side, the disc spring 17 is squeezed, and the disc spring 17 gradually reduces the squeezing force on the friction plate assembly 6.

[0037] The motor front cover 3 includes a connecting cylinder 21 and a brake cylinder 22. The multifunctional brake device is arranged in a cavity formed by the connecting cylinder 21 and the brake cylinder 22. The connecting cylinder 21 is arranged between the brake cylinder 22 and the stator 1. A spring groove 23 is arranged in the connecting cylinder 21. The disc spring 17 is installed in the spring groove 23. The inner end of the disc spring 17 and the spring groove 23 are in contact with each other. The outer end of the disc spring 17 is aligned with the contact point of the parking brake piston 16, and the middle of the disc spring 17 is aligned with the contact point of the second pressure plate 20. When the disc spring 17 is subjected to force, the outer end of the disc spring 17 will move backward, and the middle position of the disc spring 17 will also move backward; when the disc spring 17 is not subjected to force, the outer end of the disc spring 17 will move forward, and the middle position of the disc spring 17 will also move forward. Due to the difference in torque between the outer end and the middle position, it can be known that when the second pressure plate 20 is squeezed at the middle position, the middle position can apply more force to the second pressure plate 20, thereby enhancing the braking torque of the brake assembly.

[0038] The inner end of the second pressure plate 20 is provided with an inner hole structure 24, and the lower end of the spring groove 23 is provided with a protrusion 25. The protrusion 25 enters or moves out of the inner hole structure 24 as the disc spring 17 and the second pressure plate 20 are squeezed. The inner hole structure 24 is mainly used to make way for the protrusion 25 and improve the assembly efficiency when assembling the hydraulic motor. An oil drain pipe 33 is provided in the spring groove 23, and the oil drain pipe 33 is aligned with the side wall of the disc spring 17. The brake cavity 18 is connected to the spring groove 23, so that the pressure at both ends of the friction plate assembly and the disc spring is basically the same, so that the pressure at both ends of the friction plate assembly 6 is basically the same, avoiding excessive liquid pressure at one end, which affects the normal operation of the brake assembly. The present invention adopts a brake placed at the front end of the motor: the outer sides of the driving brake oil chamber 12 and the parking brake oil chamber 15 are both motor front cover 3. When the performance of the seal of the brake oil chamber deteriorates due to aging, the hydraulic oil in the brake oil chamber flows into the motor housing and then flows out from the motor oil drain port, which can realize the braking function and the outflow of hydraulic oil will not affect the realization of other functions of the motor. If a traditional brake is placed at the rear end of the motor rear cover 4: the service brake oil chamber 12 is adjacent to the parking brake oil chamber 15 and separated by a seal. When the performance of the seal here deteriorates and oil leaks, the pressure oil of the two oil chambers will interfere with each other, causing accidental braking or brake failure, thereby affecting the realization of the braking function and causing hidden dangers of safety accidents. Therefore, the service brake oil chamber 12 and the parking brake oil chamber 15 are far apart, and even if the sealing performance of the seal used deteriorates due to aging, the two oil chambers will not interfere with each other. Therefore, the sealing requirements for the seal are not high, and the interference between the service brake and the parking brake is avoided. The braking effectiveness can be improved, the danger caused by accidental brake release can be avoided, and the performance requirements for the seal can be reduced.

[0039] A flushing oil port 26 is provided in the brake cavity 18. The hydraulic oil enters from the flushing oil port 26 and passes through the friction plate assembly 6 to take away heat and iron filings, and is finally discharged from the oil drain port of the motor, which accelerates the heat dissipation of the hydraulic motor and improves the service life. A plurality of annular grooves 31 and a plurality of radial grooves 32 are provided on the static friction plate, and the annular grooves 31 and the radial grooves 32 are connected. The cooling hydraulic oil passes through the annular grooves 31 and the radial grooves 32 to achieve a better heat dissipation effect. A avoidance groove 27 is provided at the inner end of the spring groove 23. The inner end of the disc spring 17 moves toward the avoidance groove 27. The diameter of the avoidance groove 27 is smaller than the inner end diameter of the disc spring 17. Due to process limitations, it is often impossible to completely achieve a right angle at the right angle of the mechanism, and there will be a certain rounded corner structure. In order to avoid the rounded corner structure from affecting the operation of the disc spring 17, the design of the avoidance groove 27 will neither increase the size of the spring groove 23, causing the disc spring 17 to be unable to be fixed, nor interfere with the operation of the disc spring 17 due to the rounded corner. The outer end of the second pressing plate 20 and the disc spring 17 are pressed against each other, and a pressing protrusion 28 is provided on the outer end of the second pressing plate 20. The pressing protrusion 28 prevents the second pressing plate 20 and the disc spring 17 from fitting against each other to form an adsorption force when they are pressed. Under conventional design, the second pressing plate 20 and the disc spring 17 are both planes. When the two are pressed against each other, they are close together, which will cause the two planes to fit against each other, thereby generating an adsorption force. The pressing protrusion 28 is designed to avoid this situation.

[0040] A first concave cavity 41 and a second concave cavity 42 are provided on the inner wall of the brake cylinder body 22. The first concave cavity 41 is provided inside the second concave cavity 42. A partition wall 43 is provided between the first concave cavity 41 and the second concave cavity 42. The first concave cavity 41, the second concave cavity 42 and the spring groove 23 are connected to each other. The inner end of the spring groove 23 is aligned with the first concave cavity 41, and the outer end of the spring groove 23 is aligned with the second concave cavity 42. The first concave cavity 41 includes a service brake oil cavity 12, an active cavity of a service brake piston and a brake cavity 18. The second concave cavity 42 includes a parking brake oil cavity 15 and an active cavity of a parking brake piston.

[0041] The above is a detailed introduction to a hydraulic motor with integrated driving brake and parking brake provided by the present invention. The principle and implementation mode of the present invention are described in detail using specific examples. The description of the above embodiments is only used to help understand the present invention and its core ideas. It should be pointed out that for ordinary technicians in this technical field, the present invention can also be improved and modified without departing from the principle of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A hydraulic motor with integrated driving brake and parking brake, comprising a stator, a rotor assembly, a motor front cover and a motor rear cover, wherein the rotor assembly is connected to an output shaft, a distribution shaft is arranged in the motor rear cover, and the output shaft passes through the motor front cover to connect to the outside, characterized in that: A multifunctional brake device is arranged in the front cover of the motor, and the multifunctional brake device includes a friction plate assembly, a driving brake control assembly and a parking brake control assembly. The friction plate assembly includes a plurality of dynamic friction plates and a plurality of static friction plates. The driving brake control assembly includes a driving brake control oil port, a driving brake oil chamber and a driving brake piston. The parking brake control assembly includes a parking brake oil port, a parking brake oil chamber, a parking brake piston and a disc spring. The friction plate assembly is installed in the brake chamber. A movable first pressure plate and a movable second pressure plate are respectively arranged on both sides of the friction plate assembly. The driving brake piston is connected to the first pressure plate, and the disc spring squeezes the second pressure plate when no force is applied. When hydraulic oil is rushed into the service brake control oil port, the service brake piston squeezes the first pressure plate, so that the friction plate assembly generates a braking torque. The greater the pressure of the hydraulic oil rushed in, the greater the braking torque is, which plays a service brake effect; when the service brake control oil port stops rushing into the hydraulic oil and the parking brake oil port stops rushing into the hydraulic oil, the parking brake piston squeezes the disc spring, so that the disc spring no longer squeezes the second pressure plate, and the hydraulic motor is not affected by the braking torque; when the service brake control oil port stops rushing into the hydraulic oil and the parking brake oil port stops rushing into the hydraulic oil, the disc spring squeezes the second pressure plate, so that the friction plate assembly generates a braking torque, which plays a parking brake effect; The motor front cover includes a connecting cylinder body and a brake cylinder body. The multifunctional braking device is arranged in a cavity formed by the connecting cylinder body and the brake cylinder body. The connecting cylinder body is arranged between the brake cylinder body and the stator. A spring groove is arranged in the connecting cylinder body. The disc spring is installed in the spring groove. The inner end of the disc spring and the spring groove contact each other. The outer end of the disc spring is aligned with the contact point of the parking brake piston. The middle part of the disc spring is aligned with the contact point of the second pressure plate.

2. The hydraulic motor integrating service brake and parking brake according to claim 1, characterized in that: The parking brake piston and the friction plate assembly are arranged on the front side of the disc spring. When the parking brake piston is squeezed by the hydraulic oil and moves toward the rear side, the disc spring is squeezed and the disc spring gradually reduces the squeezing force on the friction plate assembly.

3. The hydraulic motor integrating service brake and parking brake according to claim 1, characterized in that: The inner end of the second pressing plate is provided with an inner hole structure, and the lower end of the spring groove is provided with a protrusion, and the protrusion enters or moves out of the inner hole structure as the disc spring and the second pressing plate are squeezed.

4. The hydraulic motor integrating service brake and parking brake according to claim 1, characterized in that: An oil drain pipe is arranged in the spring groove, and the oil drain pipe is aligned with the side wall of the disc spring, so that the brake cavity is connected to the spring groove, so that the pressure at both ends of the friction plate assembly and the disc spring is basically consistent.

5. The hydraulic motor integrating service brake and parking brake according to claim 1, characterized in that: The brake cavity is provided with a flushing oil port, and hydraulic oil enters from the flushing oil port and passes through the friction plate assembly to take away heat and iron filings, and is finally discharged from the oil drain port of the motor.

6. The hydraulic motor integrating service brake and parking brake according to claim 1, characterized in that: The inner end of the spring groove is provided with an escape groove. When the disc spring is squeezed, the inner end of the disc spring moves toward the escape groove. The diameter of the escape groove is smaller than the inner end diameter of the disc spring.

7. The hydraulic motor integrating service brake and parking brake according to claim 1, characterized in that: The outer end of the second pressing plate and the disc spring are pressed against each other, and an extrusion protrusion is arranged on the outer end of the second pressing plate. The extrusion protrusion prevents the second pressing plate and the disc spring from fitting against each other and forming an adsorption force during extrusion.

8. The hydraulic motor integrating service brake and parking brake according to claim 1, characterized in that: A first concave cavity and a second concave cavity are arranged on the inner wall of the brake cylinder body, the first concave cavity is arranged on the inner side of the second concave cavity, a partition wall is arranged between the first concave cavity and the second concave cavity, the inner end of the spring groove is aligned with the first concave cavity, and the outer end of the spring groove is aligned with the second concave cavity, the first concave cavity includes the service brake oil cavity, the active cavity of the service brake piston and the brake cavity, and the second concave cavity includes the parking brake oil cavity and the active cavity of the parking brake piston.

9. The hydraulic motor integrating service brake and parking brake according to claim 1, characterized in that: The static friction plate is provided with a plurality of annular grooves and a plurality of radial grooves, and the annular grooves are connected with the radial grooves.

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