Ball piston hydraulic motor

Abstract

The present invention discloses a ball plunger hydraulic motor comprising a housing, a stator fixedly mounted within the housing, a rotor rotatably mounted within the housing, a ball plunger structure mounted between the stator and the rotor, and a brake mounted within the housing for braking the rotor. Compared to the prior art, the present invention integrates the brake within the ball plunger hydraulic motor, eliminating the need for a brake in actual use. This significantly saves space and results in a more compact structure.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic motors, in particular to a ball plunger type hydraulic motor. Background Art

[0002] A ball plunger hydraulic motor generally includes a housing, a stator, a rotor, and a ball plunger structure. When braking the rotor, an additional brake is required, which occupies a large space. Summary of the Invention

[0003] The object of the present invention is to provide a ball plunger hydraulic motor, which integrates a brake inside the ball plunger hydraulic motor so that the ball plunger hydraulic motor does not need to be equipped with a brake in actual use, thereby greatly saving space and making the structure more compact.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention discloses a ball plunger hydraulic motor, comprising a housing, a stator fixedly installed in the housing, a rotor rotatably installed in the housing, and a ball plunger structure installed between the stator and the rotor. The motor also comprises a brake for braking the rotor, wherein the brake is installed in the housing.

[0006] Preferably, the brake is a normally closed multi-disc hydraulic brake.

[0007] Preferably, the brake includes a compression spring, a piston, an outer friction plate, an outer pin shaft, an outer spacing spring, an inner friction plate, an inner pin shaft and an inner spacing spring, the outer friction plate and the inner friction plate are parallel to each other and alternately arranged; the outer pin shaft is fixed to the housing, the outer pin shaft passes through the outer friction plate and the outer spacing spring, and the outer spacing spring is located between two adjacent outer friction plates; the inner pin shaft is fixed to the rotor, the inner pin shaft passes through the inner friction plate and the inner spacing spring, and the inner spacing spring is located between two adjacent inner friction plates; the piston is slidably installed in the housing, the outer friction plate and the inner friction plate are located on a first side of the piston, and a control oil circuit connected to the first side is provided on the housing; the compression spring is located on the second side of the piston and is in a pre-compressed state to press the piston toward the outer friction plate and the inner friction plate.

[0008] Preferably, the first gap compensation structure and the second gap compensation structure are further included; the housing includes an oil pan located on one side of the ball plunger structure and a front cover located on the other side of the ball plunger structure, the stator is located between the oil pan and the front cover, and the stator is fixedly connected to the oil pan and the front cover at the same time;

[0009] The first gap compensation structure includes a first oil distribution plate, a first elastic component, and a first positioning structure; the first positioning structure passes through the first oil distribution plate and is fixed to the oil-through plate to limit the position of the first oil distribution plate, and the first oil distribution plate can slide axially along the first positioning structure; the first elastic component is located between the oil-through plate and the first oil distribution plate to apply elastic thrust to the first oil distribution plate;

[0010] The second gap compensation structure includes a second oil distribution plate, a second elastic component and a second positioning structure; the second positioning structure passes through the second oil distribution plate and is fixed on the front cover to limit the position of the second oil distribution plate, and the second oil distribution plate can slide axially along the second positioning structure; the second elastic component is located between the front cover and the second oil distribution plate to apply elastic thrust to the second oil distribution plate.

[0011] Preferably, the rotor is provided with a first through hole for accommodating hydraulic oil in the axial direction, and the oil distribution plate is provided with a second through hole for accommodating hydraulic oil, and the second through hole is communicated with the first through hole;

[0012] The oil distribution plate is provided with a first spring groove and an oil supply channel for supplying hydraulic oil, the first spring groove is located at one end of the oil supply channel and is directly opposite to the second through hole of the first oil distribution plate; the front cover is provided with a second spring groove, the second spring groove is directly opposite to the second through hole of the second oil distribution plate;

[0013] The first elastic component includes a first spring and a first spring seat, the first spring is located in the first spring groove; the first spring seat includes a first cylinder and a first inner rib fixed to one end of the first cylinder, the first cylinder is sleeved on the outside of the first spring and is sealed with the inner wall of the first spring groove, one side of the first inner rib abuts against the first spring, and the other side of the first inner rib is sealed with the first oil distribution plate;

[0014] The second elastic component includes a second spring and a second spring seat, and the second spring is located in the second spring groove; the second spring seat includes a second cylinder and a second inner rib fixed to one end of the second cylinder, the second cylinder is sleeved on the outside of the second spring and is sealed with the inner wall of the second spring groove, one end of the second inner rib is against the second spring, and the other end of the second inner rib is sealed with the second oil distribution plate.

[0015] Preferably, it includes multiple first sealing rings, the first cylinder and the inner wall of the first spring groove are sealed connected by at least one first sealing ring, the second cylinder and the inner wall of the second spring groove are sealed connected by at least one first sealing ring, and the inner wall of the first spring groove and the inner wall of the second spring groove are both provided with a first sealing ring groove for accommodating the first sealing ring.

[0016] Preferably, it also includes multiple second sealing rings, the first inner rib and the first oil distribution plate are sealed together through the second sealing rings, the second inner rib and the second oil distribution plate are sealed together through the second sealing rings, and the first oil distribution plate and the second oil distribution plate are both provided with second sealing ring grooves for accommodating the second sealing rings.

[0017] Preferably, the oil pan is rotatably connected to the rotor via a first bearing, and the front cover is rotatably connected to the rotor via a second bearing.

[0018] Compared with the prior art, the present invention has achieved the following technical effects:

[0019] The present invention integrates the brake into the interior of the ball plunger type hydraulic motor, so there is no need to purchase an additional brake during use, and installation space is saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a schematic structural diagram of the ball plunger hydraulic motor of this embodiment;

[0022] Figure 2 for Figure 1 Cross-sectional view along AA direction;

[0023] Figure 3 is a schematic diagram of a first gap compensation structure and a second gap compensation structure;

[0024] Explanation of the accompanying drawings: 1-brake; 2-oil pan; 3-rotor; 4-first gap compensation structure; 5-stator; 6-ball plunger structure; 7-front cover; 8-second gap compensation structure; 101-compression spring; 102-piston; 103-outer friction plate; 104-inner friction plate; 401-first oil distribution plate; 402-first spring; 403-first spring seat; 404-first positioning structure; 405-first bearing; 406-first sealing ring; 407-second sealing ring; 801-second oil distribution plate; 802-second spring; 803-second spring seat; 804-second positioning structure; 805-second bearing. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] The object of the present invention is to provide a ball plunger hydraulic motor, which integrates a brake inside the ball plunger hydraulic motor so that the ball plunger hydraulic motor does not need to be equipped with a brake in actual use, thereby greatly saving space and making the structure more compact.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figure 1-3 As shown, this embodiment provides a ball plunger hydraulic motor, including a housing, a stator 5 fixedly installed in the housing, a rotor 3 rotatably installed in the housing, and a ball plunger structure 6 installed between the stator 5 and the rotor 3, and also includes a brake 1 for braking the rotor 3, and the brake 1 is installed in the housing.

[0029] In this embodiment, the brake 1 is integrated into the ball plunger hydraulic motor, so that the ball plunger hydraulic motor does not need to be additionally equipped with the brake 1 in actual use, thereby greatly saving space and making the structure more compact.

[0030] Furthermore, the brake 1 of this embodiment is preferably a normally closed multi-disc hydraulic brake. The normally closed multi-disc hydraulic brake has a relatively compact structure and can save installation space.

[0031] Specifically, in this embodiment, the brake 1 includes a compression spring 101, a piston 102, an outer friction plate 103, an outer pin, an outer spacing spring, an inner friction plate 104, an inner pin, and an inner spacing spring. The outer friction plates 103 and inner friction plates 104 are arranged parallel to each other and alternately. The outer pin is fixed to the housing, passing through the outer friction plates 103 and the outer spacing spring. The outer spacing spring is located between two adjacent outer friction plates 103. The inner pin is fixed to the rotor 3, passing through the inner friction plates 104 and the inner spacing spring. The inner spacing spring is located between two adjacent inner friction plates 104. The piston 102 is slidably mounted within the housing. The outer and inner friction plates 103 and 104 are located on a first side of the piston 102. A control oil passage is provided in the housing, communicating with the first side. The compression spring 101 is located on a second side of the piston 102 and is pre-compressed to press the piston 102 against the outer and inner friction plates 103 and 104.

[0032] This brake 1 is a highly integrated, compact device. When the brake 1 is closed, the compression spring 101 presses the piston 102 against the outer friction plate 103 and the inner friction plate 104, bringing them into contact. This puts the rotor 3 into a braking state. When the brake 1 is opened, hydraulic oil is introduced into the control oil circuit, pushing the piston against the compression spring 101. The inner and outer spacer springs separate the inner and outer friction plates. Therefore, when the brake 1 is opened, there is no friction, wear, or heat generation at this location. This brake 1 can be used for braking high-speed rotating shafts and offers advantages such as high-pressure resistance, low cost, and reliable performance.

[0033] Furthermore, the ball plunger hydraulic motor of this embodiment also includes a first clearance compensation structure 4 and a second clearance compensation structure 8, which are used to automatically compensate for the clearance between the rotor 3 and its adjacent structures after wear of the sliding friction contact surface. Specifically, the housing includes an oil pan 2 located on one side of the ball plunger structure 6 and a front cover 7 located on the other side of the ball plunger structure 6. The stator 5 is located between the oil pan 2 and the front cover 7 and is fixedly connected to both the oil pan 2 and the front cover 7. The first clearance compensation structure 4 includes a first oil distribution plate 401, a first elastic component, and a first positioning structure 404. The first positioning structure 404 passes through the first oil distribution plate 401 and is fixed to the oil distribution plate 2 to limit the position of the first oil distribution plate 401. The first oil distribution plate 401 can slide axially along the first positioning structure 404. The first elastic component is located between the oil distribution plate 2 and the first oil distribution plate 401 to apply elastic thrust to the first oil distribution plate 401. The second clearance compensation structure 8 includes a second oil distribution plate 801, a second elastic component, and a second positioning structure 804. The second positioning structure 804 passes through the second oil distribution plate 801 and is fixed to the front cover 7 to limit the position of the second oil distribution plate 801. The second oil distribution plate 801 can slide axially along the second positioning structure 804. The second elastic component is located between the front cover 7 and the second oil distribution plate 801 to apply an elastic thrust to the second oil distribution plate 801.

[0034] During operation, the first elastic component presses the first oil distribution plate 401 toward the rotor 3, while the second elastic component presses the second oil distribution plate 801 toward the rotor 3. This allows the rotor 3 to vibrate within a certain axial range. Once stabilized, the rotor 3 is subjected to balanced axial forces. As the rotor 3 rotates, both the first and second oil distribution plates 401, 801, experience sliding friction against the rotor 3. If wear occurs between the contact surfaces of the first and second oil distribution plates 401 and 801, the first and second oil distribution plates 401 and 801, respectively, move a certain distance toward the rotor 3 under the pressure of the first and second elastic components, respectively, achieving automatic compensation for the clearance.

[0035] Furthermore, in this embodiment, a first through hole for accommodating hydraulic oil is axially provided on the rotor 3, and a second through hole for accommodating hydraulic oil is provided on the oil distribution plate, and the second through hole is connected to the first through hole. A first spring groove and an oil supply channel for supplying hydraulic oil are provided on the oil distribution plate 2. The first spring groove is located at one end of the oil supply channel and is directly opposite to the second through hole of the first oil distribution plate 401. A second spring groove is provided on the front cover 7, and the second spring groove is directly opposite to the second through hole of the second oil distribution plate 801. The first elastic component includes a first spring 402 and a first spring seat 403. The first spring 402 is located in the first spring groove. The first spring seat 403 includes a first cylinder and a first inner rib fixed to one end of the first cylinder. The first cylinder is sleeved on the outside of the first spring 402 and is sealed to the inner wall of the first spring groove. One side of the first inner rib abuts against the first spring 402, and the other side of the first inner rib is sealed to the first oil distribution plate 401. The second elastic assembly includes a second spring 802 and a second spring seat 803. The second spring 802 is located in the second spring groove. The second spring seat 803 includes a second cylinder and a second inner rib fixed to one end of the second cylinder. The second cylinder is sleeved on the outside of the second spring 802 and is sealed to the inner wall of the second spring groove. One end of the second inner rib abuts against the second spring 802, and the other end of the second inner rib is sealed to the second oil distribution plate 801.

[0036] Because first and second oil distribution plates 401, 801 are positioned on either side of rotor 3, respectively, the first oil distribution plate 401 experiences rightward pressure from the oil, which is transmitted to rotor 3. The second oil distribution plate 801 experiences leftward pressure from the oil, which is also transmitted to rotor 3 (the contact areas with the hydraulic oil on each side of the oil distribution plates are unequal). These two forces are directed in opposite directions and are of equal or nearly equal magnitude. Therefore, in addition to the approximately zero net force exerted axially by the first and second elastic components on rotor 3, the net force exerted axially by the hydraulic oil on rotor 3 also approaches zero, improving the low-speed stability of the ball plunger hydraulic motor.

[0037] There are multiple sealing connection methods mentioned above, and those skilled in the art can choose according to actual needs. In this embodiment, multiple first sealing rings 406 are included. The first cylinder is sealed to the inner wall of the first spring groove by at least one first sealing ring 406, and the second cylinder is sealed to the inner wall of the second spring groove by at least one first sealing ring 406. The inner wall of the first spring groove and the inner wall of the second spring groove are both provided with a first sealing ring 406 groove for accommodating the first sealing ring 406. In this embodiment, multiple second sealing rings 407 are also included. The first inner rib is sealed to the first oil distribution plate 401 by the second sealing ring 407, and the second inner rib is sealed to the second oil distribution plate 801 by the second sealing ring 407. The first oil distribution plate 401 and the second oil distribution plate 801 are both provided with a second sealing ring 407 groove for accommodating the second sealing ring 407. The first sealing ring 406 and the second sealing ring 407 are used to improve the sealing performance of the hydraulic oil and minimize the leakage of the hydraulic oil.

[0038] There are many types of positioning structures, as long as they can circumferentially limit the first oil distribution plate 401 or the second oil distribution plate 801. In this embodiment, the first positioning structure 404 and the second positioning structure 804 are both positioning screws. Those skilled in the art can also choose other positioning structures such as bolts and studs.

[0039] In this embodiment, the oil pan 2 and the rotor 3 are rotatably connected via a first bearing 405, and the front cover 7 and the rotor 3 are rotatably connected via a second bearing 805. Depending on actual needs, those skilled in the art may also rotatably connect the rotor 3 to other fixed structures on the housing.

[0040] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A ball plunger hydraulic motor comprising a housing, a stator fixedly mounted in the housing, a rotor rotatably mounted in the housing, and a ball plunger structure mounted between the stator and the rotor, characterized in that: Also included is a brake for braking the rotor, wherein the brake is mounted in the housing; The brake is a normally closed multi-disc hydraulic brake; The housing further comprises a first clearance compensation structure and a second clearance compensation structure; the housing comprises an oil pan located on one side of the ball plunger structure and a front cover located on the other side of the ball plunger structure; the stator is located between the oil pan and the front cover, and the stator is fixedly connected to both the oil pan and the front cover; The first gap compensation structure includes a first oil distribution plate, a first elastic component, and a first positioning structure; the first positioning structure passes through the first oil distribution plate and is fixed to the oil-through plate to limit the position of the first oil distribution plate, and the first oil distribution plate can slide axially along the first positioning structure; the first elastic component is located between the oil-through plate and the first oil distribution plate to apply elastic thrust to the first oil distribution plate; The second gap compensation structure includes a second oil distribution plate, a second elastic component, and a second positioning structure; the second positioning structure passes through the second oil distribution plate and is fixed to the front cover to limit the position of the second oil distribution plate, and the second oil distribution plate can slide axially along the second positioning structure; the second elastic component is located between the front cover and the second oil distribution plate to apply elastic thrust to the second oil distribution plate; The rotor is provided with a first through hole for accommodating hydraulic oil in the axial direction, and the oil distribution plate is provided with a second through hole for accommodating hydraulic oil, and the second through hole is communicated with the first through hole; The oil distribution plate is provided with a first spring groove and an oil supply channel for supplying hydraulic oil, the first spring groove is located at one end of the oil supply channel and is directly opposite to the second through hole of the first oil distribution plate; the front cover is provided with a second spring groove, the second spring groove is directly opposite to the second through hole of the second oil distribution plate; The first elastic component includes a first spring and a first spring seat, the first spring is located in the first spring groove; the first spring seat includes a first cylinder and a first inner rib fixed to one end of the first cylinder, the first cylinder is sleeved on the outside of the first spring and is sealed with the inner wall of the first spring groove, one side of the first inner rib abuts against the first spring, and the other side of the first inner rib is sealed with the first oil distribution plate; The second elastic component includes a second spring and a second spring seat, and the second spring is located in the second spring groove; the second spring seat includes a second cylinder and a second inner rib fixed to one end of the second cylinder, the second cylinder is sleeved on the outside of the second spring and is sealed with the inner wall of the second spring groove, one end of the second inner rib is against the second spring, and the other end of the second inner rib is sealed with the second oil distribution plate.

2. The ball piston type hydraulic motor according to claim 1, characterized in that: The brake includes a compression spring, a piston, an outer friction plate, an outer pin shaft, an outer spacing spring, an inner friction plate, an inner pin shaft and an inner spacing spring, the outer friction plate and the inner friction plate are parallel to each other and alternately arranged; the outer pin shaft is fixed to the housing, the outer pin shaft passes through the outer friction plate and the outer spacing spring, and the outer spacing spring is located between two adjacent outer friction plates; the inner pin shaft is fixed to the rotor, the inner pin shaft passes through the inner friction plate and the inner spacing spring, and the inner spacing spring is located between two adjacent inner friction plates; the piston is slidably installed in the housing, the outer friction plate and the inner friction plate are located on a first side of the piston, and a control oil circuit connected to the first side is provided on the housing; the compression spring is located on the second side of the piston and is in a pre-compressed state to press the piston toward the outer friction plate and the inner friction plate.

3. The ball piston type hydraulic motor according to claim 1, characterized in that: It includes multiple first sealing rings, the first cylinder and the inner wall of the first spring groove are sealed by at least one first sealing ring, the second cylinder and the inner wall of the second spring groove are sealed by at least one first sealing ring, and the inner wall of the first spring groove and the inner wall of the second spring groove are both provided with a first sealing ring groove for accommodating the first sealing ring.

4. The ball piston type hydraulic motor according to claim 1, characterized in that: It also includes multiple second sealing rings, the first inner rib and the first oil distribution plate are sealed together through the second sealing rings, the second inner rib and the second oil distribution plate are sealed together through the second sealing rings, and the first oil distribution plate and the second oil distribution plate are both provided with second sealing ring grooves for accommodating the second sealing rings.

5. The ball piston type hydraulic motor according to claim 1, characterized in that: The oil pan is rotatably connected to the rotor via a first bearing, and the front cover is rotatably connected to the rotor via a second bearing.

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