A high power density hydraulic motor based on an incomplete gear rack drive

Abstract

The application discloses a high-power-density hydraulic motor based on an incomplete gear and rack transmission. The hydraulic motor comprises a mechanical transmission mechanism and a hydraulic control circuit. The mechanical transmission mechanism comprises an outer shell, a gear shaft in the outer shell, a first transmission assembly and a second transmission assembly. The gear shaft is sleeved in the first transmission assembly and the second transmission assembly. The first transmission assembly and the second transmission assembly are arranged perpendicularly and orthogonally. The hydraulic control circuit is communicated with the first transmission assembly and the second transmission assembly respectively. The first transmission assembly and the second transmission assembly are driven to move alternately by the hydraulic control circuit, and the gear shaft is driven to rotate, so that the continuous rotation of the gear shaft is realized. The piston hydraulic cylinder stably drives the rack to move in a straight line, the gear and the rack are engaged to realize the conversion from the straight line motion to the rotary motion, the output torque is improved, the output rotating speed is reduced, the high-power-density output is realized, and the hydraulic control principle is simple, reliable and easy to lock.

Description

Technical Field

[0001] This invention relates to the field of hydraulic transmission, and specifically to a high-power-density hydraulic motor based on incomplete gear and rack transmission. Background Technology

[0002] A hydraulic motor is a hydraulic actuator that outputs rotary motion. Traditional hydraulic motors typically use radial piston or vane structures. For low-speed, heavy-load applications, traditional low-speed hydraulic motors often use radial piston structures. However, these motors consist of components such as a stator, cylinder, distribution shaft, and piston, making them complex and bulky, and unsuitable for some special applications.

[0003] To achieve high power density in low-speed hydraulic motors, some low-speed, high-torque hydraulic motors with composite structures have emerged, but problems such as system complexity or unstable torque still exist. Summary of the Invention

[0004] To address the problems in the background art, this invention proposes a high-power-density hydraulic motor based on incomplete gear and rack transmission. This invention combines multiple gear and rack transmission mechanisms with a hydraulic control circuit, achieving low-speed output and making it suitable for driving rotary mechanisms with low-speed, high-torque operating conditions.

[0005] The technical solution adopted in this invention is:

[0006] It includes a mechanical transmission mechanism and a hydraulic control circuit, which are connected by pipes.

[0007] The mechanical transmission mechanism includes an outer casing and a gear shaft, a first transmission component, and a second transmission component disposed inside the outer casing. The gear shaft is fitted into the first transmission component and the second transmission component. The first transmission component and the second transmission component are arranged perpendicularly and orthogonally to each other. The hydraulic control circuit is connected to the first transmission component and the second transmission component respectively. The hydraulic control circuit drives the first transmission component and the second transmission component to move alternately, thereby driving the gear shaft to rotate and realizing the continuous rotation of the gear shaft.

[0008] The hydraulic control circuit includes an oil pump, an oil tank, a two-position four-way solenoid valve, and a control device;

[0009] The inlet P of the two-position four-way solenoid valve is connected to the oil tank via an oil pump, and the return port T of the two-position four-way solenoid valve is also connected to the oil tank. Both the oil port A and the oil port B of the two-position four-way solenoid valve are connected to the first transmission assembly and the second transmission assembly. The control device and the two-position four-way solenoid valve are electrically connected. The control device controls the two-position four-way solenoid valve to switch between controlling the first transmission assembly and the second transmission assembly to work alternately and drive the gear shaft to rotate continuously.

[0010] The first transmission assembly includes a first hydraulic cylinder and a first incomplete gear;

[0011] The second transmission assembly includes a second hydraulic cylinder and a second incomplete gear;

[0012] The middle part of the first hydraulic cylinder and the second hydraulic cylinder is compressed to ensure that the first hydraulic cylinder and the second hydraulic cylinder are arranged perpendicularly and orthogonally to each other. The first hydraulic cylinder is provided with a first double rack piston. The middle part of the first double rack piston is flat. The first double rack piston and the inner wall of the first hydraulic cylinder are fitted with a clearance to slide in the first hydraulic cylinder.

[0013] The second hydraulic cylinder is equipped with a second double rack piston. The middle part of the second double rack piston is flat. The second double rack piston and the inner wall of the second hydraulic cylinder are fitted together to slide inside the second hydraulic cylinder.

[0014] The first double rack piston meshes with the first incomplete gear, and the second double rack piston meshes with the second incomplete gear. Both the first and second incomplete gears are quarter-gears with teeth on a quarter-circumference. The first and second incomplete gears are coaxially fixed to the gear shaft. The teeth of the first and second incomplete gears are set at the same angle. The first and second double rack pistons reciprocate simultaneously, alternately meshing with their respective first and second incomplete gears, thereby driving the gear shaft to rotate continuously on the same axis.

[0015] The oil port A of the two-position four-way solenoid valve is connected to one side cavity of the first hydraulic cylinder and the second hydraulic cylinder respectively, and the oil port B of the two-position four-way solenoid valve is connected to the other side cavity of the first hydraulic cylinder and the second hydraulic cylinder respectively.

[0016] When the oil pump is working, the control device controls the two-position four-way solenoid valve to switch the control oil to be pumped into the two chambers of the first hydraulic cylinder and the second hydraulic cylinder respectively, thereby driving the first double rack piston and the second double rack piston to reciprocate alternately. The first double rack piston and the second double rack piston alternately serve as driving force to drive the gear shaft to rotate continuously through the gear rack pair.

[0017] When the two-position four-way solenoid valve switches the control oil to one side chamber of the first hydraulic cylinder and the second hydraulic cylinder respectively, the first double rack piston of the first hydraulic cylinder meshes with the first incomplete gear and drives the gear shaft to rotate. At this time, the second double rack piston and the second incomplete gear of the second hydraulic cylinder do not mesh and therefore do not drive the gear shaft to rotate.

[0018] When the two-position four-way solenoid valve switches the control oil to the other side chamber of the first hydraulic cylinder and the second hydraulic cylinder respectively, the second double rack piston of the second hydraulic cylinder meshes with the second incomplete gear and drives the gear shaft to rotate. At this time, the first double rack piston and the first incomplete gear of the first hydraulic cylinder do not mesh and therefore do not drive the gear shaft to rotate.

[0019] After the first incomplete gear and the second incomplete gear rotate 180 degrees simultaneously, the control device controls the two-position four-way solenoid valve to switch the oil inlet and outlet, thereby switching the movement direction of the first double rack piston and the second double rack piston.

[0020] The gear shaft, the first incomplete gear, and the second incomplete gear are provided with keyways, and the key is fixedly connected in the keyway. The first incomplete gear and the second incomplete gear are respectively coaxially fixedly connected to the gear shaft by the key.

[0021] This invention utilizes a control device that controls a two-position four-way solenoid valve to switch the flow of hydraulic fluid into the two chambers of the first and second hydraulic cylinders when the oil pump is working. This, in turn, drives the first and second double-rack pistons to reciprocate alternately. The first and second double-rack pistons alternately act as driving forces, which drive the gear shaft to rotate continuously via the gear and rack pair. Low-speed, high-torque is obtained through the engagement of the hydraulic piston pressure and the gear and rack mechanism. The staggered arrangement of the two sets of hydraulic cylinders is compact and can achieve high-power-density continuous low-speed rotational output.

[0022] The beneficial effects of this invention are:

[0023] 1. This invention can achieve low-speed, high-torque output of the gear shaft.

[0024] 2. This invention achieves rotational relay through two sets of cross-arranged incomplete gears and double rack piston hydraulic cylinder groups, enabling continuous rotational output.

[0025] 3. This invention enables repetitive linear motion of two sets of hydraulic cylinders, with a simple and reliable oil pressure circuit, simplifying control and making the rotation of the hydraulic motor smooth and continuous, facilitating locking. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall transmission mechanism of the present invention.

[0027] Figure 2 This is a side view of the transmission mechanism in this invention.

[0028] Figure 3 This is a partial structural diagram of the first hydraulic cylinder in this invention.

[0029] Figure 4 Another sectional view of the first hydraulic cylinder in this invention.

[0030] Figure 5 This is a schematic diagram of a hydraulic control system.

[0031] Figure 6 This is a schematic diagram of a continuous rotary motion in a gear and rack relay system.

[0032] In the diagram, 1 is the outer casing; 2 is the first hydraulic cylinder; 3 is the gear shaft; 4 is the second hydraulic cylinder; 5 is the first double rack piston; 6 is the first incomplete gear; 7 is the control device; 8 is the two-position four-way solenoid valve; 9 is the oil tank; 10 is the oil pump; 11 is the second double rack piston; and 12 is the second incomplete gear. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0034] The implementation process of the embodiments of the present invention is as follows:

[0035] like Figure 1 , Figure 2 As shown, it includes a mechanical transmission mechanism and a hydraulic control circuit, which are connected by a pipeline;

[0036] The mechanical transmission mechanism includes a housing 1 and a gear shaft 3, a first transmission component, and a second transmission component disposed inside the housing 1. The gear shaft 3 is fitted into the first transmission component and the second transmission component. The first transmission component and the second transmission component are arranged perpendicularly and orthogonally to each other. The hydraulic control circuit is connected to the first transmission component and the second transmission component respectively. The hydraulic control circuit drives the first transmission component and the second transmission component to move alternately, thereby driving the gear shaft 3 to rotate and realizing the continuous rotation of the gear shaft 3.

[0037] The hydraulic control circuit includes an oil pump 10, an oil tank 9, a two-position four-way solenoid valve 8, and a control device 7;

[0038] The oil inlet P of the two-position four-way solenoid valve 8 is connected to the oil tank 9 through the oil pump 10, and the oil return port T of the two-position four-way solenoid valve 8 is connected to the oil tank 9. The oil ports A and B of the two-position four-way solenoid valve 8 are both connected to the first transmission assembly and the second transmission assembly. The control device 7 is electrically connected to the two-position four-way solenoid valve 8. The control device 7 controls the two-position four-way solenoid valve 8 to switch and control the first transmission assembly and the second transmission assembly to work alternately to drive the gear shaft 3 to rotate continuously.

[0039] The first transmission assembly includes a first hydraulic cylinder 2 and a first incomplete gear 6;

[0040] The second transmission assembly includes a second hydraulic cylinder 4 and a second incomplete gear 12;

[0041] like Figure 3As shown, the middle part of the first hydraulic cylinder 2 and the second hydraulic cylinder 4 is compressed to ensure that the first hydraulic cylinder 2 and the second hydraulic cylinder 4 are arranged perpendicularly and orthogonally to each other. The first hydraulic cylinder 2 is provided with a first double rack piston 5. The middle part of the first double rack piston 5 is flat. The first double rack piston 5 and the inner wall of the first hydraulic cylinder 2 are fitted with a clearance to slide in the first hydraulic cylinder 2.

[0042] The second hydraulic cylinder 4 is provided with a second double rack piston 11. The middle part of the second double rack piston 11 is flat. The second double rack piston 11 and the inner wall of the second hydraulic cylinder 4 are fitted together to slide within the second hydraulic cylinder 4.

[0043] like Figure 4 As shown, the first double rack piston 5 meshes with the first incomplete gear 6, and the second double rack piston 11 meshes with the second incomplete gear 12. The first incomplete gear 6 and the second incomplete gear 12 are coaxially fixed to the gear shaft 3. The teeth of the first incomplete gear 6 and the teeth of the second incomplete gear 11 are set at the same angle. The first double rack piston 5 and the second double rack piston 11 move back and forth simultaneously, alternately meshing with their respective first incomplete gear 6 and second incomplete gear 11, thereby driving the gear shaft 3 to rotate continuously coaxially.

[0044] The first incomplete gear 6 and the second incomplete gear 12 are both quarter gears with teeth on a quarter circumference.

[0045] The oil port A of the two-position four-way solenoid valve 8 is connected to one side cavity of the first hydraulic cylinder 2 and the second hydraulic cylinder 4 respectively, and the oil port B of the two-position four-way solenoid valve 8 is connected to the other side cavity of the first hydraulic cylinder 2 and the second hydraulic cylinder 4 respectively.

[0046] When the oil pump 10 is working, the control device 7 controls the two-position four-way solenoid valve 8 to switch and control the oil to be pumped into the two chambers of the first hydraulic cylinder 2 and the second hydraulic cylinder 4 respectively, thereby driving the first double rack piston 5 and the second double rack piston 11 to reciprocate alternately. The first double rack piston 5 and the second double rack piston 11 alternately serve as driving force to drive the gear shaft 3 to rotate continuously through the gear rack pair.

[0047] When the first double rack piston 5 of the first hydraulic cylinder 2 drives the shaft to rotate actively through the gear rack pair, the second double rack piston 11 of the second hydraulic cylinder 4 is driven by the oil circuit to perform a driven motion. At this time, the second incomplete gear 12 does not drive the gear shaft 3 to rotate.

[0048] When the second double rack piston 11 of the second hydraulic cylinder 4 drives the shaft to rotate actively via the gear rack pair, the first double rack piston 5 of the first hydraulic cylinder 2 is driven by the oil circuit to perform a driven motion. At this time, the first incomplete gear 6 does not drive the gear shaft 3 to rotate.

[0049] When the two four-way solenoid valves 8 switch the control oil to one side chamber of the first hydraulic cylinder 2 and the second hydraulic cylinder 4 respectively, the first double rack piston 5 of the first hydraulic cylinder 2 meshes with the first incomplete gear 6 and drives the gear shaft 3 to rotate. At this time, the second double rack piston 11 and the second incomplete gear 12 of the second hydraulic cylinder 4 do not mesh and therefore do not drive the gear shaft 3 to rotate.

[0050] When the two four-way solenoid valves 8 switch the control oil to the other side chamber of the first hydraulic cylinder 2 and the second hydraulic cylinder 4 respectively, the second double rack piston 11 of the second hydraulic cylinder 4 meshes with the second incomplete gear 12, thereby driving the gear shaft 3 to rotate. At this time, the first double rack piston 5 of the first hydraulic cylinder 2 and the first incomplete gear 6 do not mesh, and therefore do not drive the gear shaft 3 to rotate.

[0051] After the first incomplete gear 6 and the second incomplete gear 12 rotate 180 degrees simultaneously, the control device 7 controls the two-position four-way solenoid valve 8 to switch the oil inlet and outlet, thereby switching the movement direction of the first double rack piston 5 and the second double rack piston 11.

[0052] The gear shaft 3, the first incomplete gear 6, and the second incomplete gear 12 are provided with keyways, and the key is fixedly connected in the keyway. The first incomplete gear 6 and the second incomplete gear 12 are respectively coaxially fixedly connected to the gear shaft 3 by the key.

[0053] like Figure 5 As shown, port A of the two-position four-way solenoid valve 8 is connected to the left chamber of the first hydraulic cylinder 2 and the upper chamber of the second hydraulic cylinder 4, and port B of the two-position four-way solenoid valve 8 is connected to the lower chamber of the second hydraulic cylinder 4 and the right chamber of the first hydraulic cylinder 2. The control device 7 controls the two-position four-way solenoid valve 8 to switch the control oil flow to the two chambers of the first hydraulic cylinder 2 and the second hydraulic cylinder 4 respectively.

[0054] When oil enters the left chamber and exits the right chamber of the first hydraulic cylinder 2, oil exits the lower chamber and enters the upper chamber of the second hydraulic cylinder 4. At this time, the first double rack piston 5 moves to the right and the second rack piston 11 moves downward. When oil enters the right chamber and exits the left and right chambers of the first hydraulic cylinder 2, oil exits the upper chamber and enters the lower chamber of the second hydraulic cylinder 4. At this time, the first double rack piston 5 moves to the left and the second rack piston 11 moves upward.

[0055] like Figure 6 As shown in the motion diagram, the first incomplete gear 6 and the second incomplete gear 12 are installed at a 90° angle, taking the counterclockwise rotation of the gear shaft 3 as an example:

[0056] like Figure 6In (a), state one, the first double rack piston 5 moves to the right, and at the same time the second rack piston 11 moves downward. The first double rack piston 5 and the first incomplete gear 6 mesh. At this time, the second double rack piston 11 and the second incomplete gear 12 are not meshed during idle stroke. After the first double rack piston 5 and the first incomplete gear 6 mesh, the gear shaft 3 rotates 90° and then enters the idle stroke, which is state two.

[0057] like Figure 6 In (b) of the second state, the second rack piston 11 moves upward while the first double rack piston 5 moves to the left. The second double rack piston 11 meshes with the second incomplete gear 12. At this time, the first double rack piston 5 and the first incomplete gear 6 are not meshed during idle stroke. After the second double rack piston 11 and the second incomplete gear 12 mesh, the gear shaft 3 rotates 90° and begins to enter the idle stroke, i.e., state three.

[0058] like Figure 6 In (c), state three, the first double rack piston 5 moves to the left, and at the same time the second rack piston 11 moves upward. The first double rack piston 5 and the first incomplete gear 6 mesh. At this time, the second double rack piston 11 and the second incomplete gear 12 are not meshed in the idle stroke. The meshing of the first double rack piston 5 and the first incomplete gear 6 drives the gear shaft 3 to rotate 90° and then begins to enter the idle stroke, i.e., state four.

[0059] like Figure 6 In state (d), the second rack piston 11 moves downward while the first double rack piston 5 moves to the right. The second double rack piston 11 meshes with the second incomplete gear 12. At this time, the first double rack piston 5 and the first incomplete gear 6 are not meshed during idle stroke. After the second double rack piston 11 and the second incomplete gear 12 mesh, the gear shaft 3 rotates 90° and then enters idle stroke, returning to state one.

[0060] The above four states cycle repeatedly. After each 180° stroke of any incomplete gear, the direction of rack movement is switched, which is to switch the direction of movement of the double rack piston. In other words, the oil inlet and outlet are switched by the control device 7, so that the two incomplete gears can rotate continuously in the same direction in a relay manner, so that the hydraulic motor can output continuous low-speed high-torque rotation.

[0061] This invention mainly utilizes the fact that when the oil pump 10 is working, the control device 7 controls the two-position four-way solenoid valve 8 to switch and control the oil to be pumped into the two chambers of the first hydraulic cylinder 2 and the second hydraulic cylinder 4 respectively, thereby driving the first double rack piston 5 and the second double rack piston 11 to reciprocate alternately. The first double rack piston 5 and the second double rack piston 11 alternately serve as driving forces to drive the gear shaft 3 to rotate continuously through the gear rack pair. The low speed and high torque are obtained by the hydraulic piston pressure meshing with the gear rack mechanism. The staggered arrangement of the two sets of hydraulic cylinders is compact and can realize high power density continuous low speed rotation output.

[0062] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A high-power-density hydraulic motor based on incomplete gear and rack transmission, characterized in that: It includes a mechanical transmission mechanism and a hydraulic control circuit, which are connected by pipes. The mechanical transmission mechanism includes an outer shell (1) and a gear shaft (3) disposed inside the outer shell (1), a first transmission assembly and a second transmission assembly; the gear shaft (3) is fitted into the first transmission assembly and the second transmission assembly, the first transmission assembly and the second transmission assembly are arranged perpendicularly and orthogonally to each other, the hydraulic control circuit is connected to the first transmission assembly and the second transmission assembly respectively, the hydraulic control circuit drives the first transmission assembly and the second transmission assembly to move alternately, thereby driving the gear shaft (3) to rotate and realize the continuous rotation of the gear shaft (3); The first transmission assembly includes a first hydraulic cylinder (2) and a first incomplete gear (6); The second transmission assembly includes a second hydraulic cylinder (4) and a second incomplete gear (12); The first hydraulic cylinder is provided with a first double rack piston (5), which meshes with a first incomplete gear (6). The second hydraulic cylinder (4) is provided with a second double rack piston (11), which meshes with the first incomplete gear (6) and the second double rack piston (11) meshes with the second incomplete gear (12). The first incomplete gear (6) and the second incomplete gear (12) are coaxially fixed to the gear shaft (3).

2. A high-power-density hydraulic motor based on incomplete gear and rack transmission according to claim 1, characterized in that: The hydraulic control circuit includes an oil pump (10), an oil tank (9), a two-position four-way solenoid valve (8), and a control device (7). The oil inlet P of the two-position four-way solenoid valve (8) is connected to the oil tank (9) through the oil pump (10), and the oil return port T of the two-position four-way solenoid valve (8) is connected to the oil tank (9). The oil ports A and B of the two-position four-way solenoid valve (8) are both connected to the first transmission component and the second transmission component. The control device (7) and the two-position four-way solenoid valve (8) are electrically connected. The control device (7) controls the two-position four-way solenoid valve (8) to switch the control of the first transmission component and the second transmission component to work alternately to drive the gear shaft (3) to rotate continuously.

3. A high-power-density hydraulic motor based on incomplete gear and rack transmission according to claim 1, characterized in that: The teeth of the first incomplete gear (6) and the teeth of the second incomplete gear (12) are set at the same angle. The first double rack piston (5) and the second double rack piston (11) move back and forth simultaneously, alternately meshing with their respective first incomplete gear (6) and second incomplete gear (12), thereby driving the gear shaft (3) to rotate coaxially and continuously.

4. A high-power-density hydraulic motor based on incomplete gear and rack transmission according to claim 3, characterized in that: The first incomplete gear (6) and the second incomplete gear (12) are both quarter gears with teeth on a quarter circumference.

5. A high-power-density hydraulic motor based on incomplete gear and rack transmission according to claim 2, characterized in that: The oil port A of the two-position four-way solenoid valve (8) is connected to one side cavity of the first hydraulic cylinder (2) and the second hydraulic cylinder (4), respectively, and the oil port B of the two-position four-way solenoid valve (8) is connected to the other side cavity of the first hydraulic cylinder (2) and the second hydraulic cylinder (4). When the oil pump (10) is working, the control device (7) controls the two-position four-way solenoid valve (8) to switch the control oil to be pumped into the two chambers of the first hydraulic cylinder (2) and the second hydraulic cylinder (4), thereby driving the first double rack piston (5) and the second double rack piston (11) to move back and forth alternately. The first double rack piston (5) and the second double rack piston (11) alternately act as driving force to drive the gear shaft (3) to rotate continuously through the gear rack pair.

6. A high-power-density hydraulic motor based on incomplete gear and rack transmission according to claim 5, characterized in that: When the two-position four-way solenoid valve (8) switches the control oil to one side chamber of the first hydraulic cylinder (2) and the second hydraulic cylinder (4), the first double rack piston (5) of the first hydraulic cylinder (2) meshes with the first incomplete gear (6) and drives the gear shaft (3) to rotate. At this time, the second double rack piston (11) and the second incomplete gear (12) of the second hydraulic cylinder (4) do not mesh and thus do not drive the gear shaft (3) to rotate. When the two-position four-way solenoid valve (8) switches the control oil to the other side chamber of the first hydraulic cylinder (2) and the second hydraulic cylinder (4), the second double rack piston (11) of the second hydraulic cylinder (4) meshes with the second incomplete gear (12) and drives the gear shaft (3) to rotate. At this time, the first double rack piston (5) of the first hydraulic cylinder (2) and the first incomplete gear (6) do not mesh and thus do not drive the gear shaft (3) to rotate.

7. A high-power-density hydraulic motor based on incomplete gear and rack transmission according to claim 3, characterized in that: After the first incomplete gear (6) and the second incomplete gear (12) rotate 180 degrees at the same time, the control device (7) controls the two-position four-way solenoid valve (8) to switch the oil inlet and outlet of the control oil, thereby switching the movement direction of the first double rack piston (5) and the second double rack piston (11).

8. A high-power-density hydraulic motor based on incomplete gear and rack transmission according to claim 3, characterized in that: The gear shaft (3), the first incomplete gear (6), and the second incomplete gear (12) are provided with keyways, and the keys are fixedly connected in the keyways. The first incomplete gear (6) and the second incomplete gear (12) are respectively coaxially fixedly connected to the gear shaft (3) by the keys.

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