Self-suction plunger and hydraulic motor adopting plunger structure

Abstract

The invention provides a self-suction plunger and a hydraulic motor adopting the plunger structure, the self-suction plunger comprises a plunger main body, a cone valve core and a spring, the cone valve core is arranged in the plunger main body and is used for realizing opening, closing and sealing by matching a cone-shaped sealing surface with the inner wall of the plunger main body, and the spring is used for pushing the cone valve core to reset. When the hydraulic motor is reversely dragged by external force and the plunger cavity of the hydraulic motor is in negative pressure, oil in the shell of the hydraulic motor can be used for supplementing the volume in the plunger cavity, and the plunger can smoothly move downwards when the oil in the plunger cavity is supplemented, so that the stress of the return plate is reduced, the return plate is prevented from being damaged, and the service life of the motor is guaranteed; and the use scene of the oil motor is widened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic components, and relates to a hydraulic actuator, in particular to a self-suction plunger and a hydraulic motor adopting the plunger structure. BACKGROUND

[0002] The hydraulic walking motor is widely used as a walking driving device of engineering machinery. However, when the hydraulic motor is used as a driving device, in special cases, the output shaft of the hydraulic motor is dragged by external force and rotates passively. Since the inlet oil supply is insufficient, the plunger cavity cannot be supplemented with oil, and the plunger cannot move downward smoothly. When the motor rotates passively, the plunger can only be moved downward by the return disc forcedly. At this time, the return disc is subjected to a large force, and the deformation and fracture of the return disc often occur, causing the hydraulic motor to fail.

[0003] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0004] The self-suction plunger and the hydraulic motor adopting the plunger structure are provided in the embodiments of the present application to solve the problem of damage to the return disc caused by insufficient oil in the plunger cavity. In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not a general review, nor is it intended to determine key / important constituent elements or delineate the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a prelude to the detailed description that follows.

[0005] In one embodiment, a self-suction plunger comprises: a plunger body; a tapered valve core arranged in the plunger body to realize opening and closing and sealing by cooperating with the inner wall of the plunger body with a tapered sealing surface, and a spring for pushing the tapered valve core to reset.

[0006] On the basis of the above scheme, the inside of the plunger body is provided with a plunger cavity for forming a sealing pair with the head of the tapered valve core; an axial center through hole is arranged at the bottom of the plunger body for flowing the pressure oil to the sliding shoe; a supplementary oil hole is arranged at the bottom of the plunger body for entering the oil in the shell into the inside of the plunger cavity.

[0007] On the basis of the above scheme, the plunger cavity has a first straight cylinder section, a variable cross-section section and a second straight cylinder section; The diameter of the first straight cylinder section is greater than the diameter of the second straight cylinder section.

[0008] Based on the above scheme, the bottom of the valve core body has a conical sealing part, and the slope of the conical sealing part is greater than the slope of the variable cross-section section.

[0009] Based on the above scheme, the cone valve core includes: Valve core body; An oil hole for the flow of oil is provided axially on the valve core body.

[0010] The valve core body has a spring cavity inside to accommodate the spring.

[0011] In one embodiment, a hydraulic motor includes a valve body, a housing, an output shaft, and a cylinder. The valve body is provided with an oil outlet and an oil inlet. One end of the oil outlet and the oil inlet are connected to an oil passage, and the other end of the oil passage is connected to the self-priming plunger.

[0012] Based on the above scheme, when the self-priming plunger is working normally, the pressure oil at the inlet pushes the cone valve core to the bottom, and the cone surface of the cone valve core forms a seal with the plunger cavity, so that the pressure inside the plunger cavity is maintained, and the pressure drives the hydraulic motor to work.

[0013] Based on the above scheme, when the hydraulic motor is in a passive rotation working state, the oil in the housing enters the plunger cavity through the replenishment oil hole.

[0014] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects: The plunger structure of this invention is self-priming. When the hydraulic motor is dragged back by an external force and the hydraulic motor plunger chamber is under negative pressure, the volume of the plunger chamber can be replenished by the oil inside the hydraulic motor housing. With the oil replenished, the plunger can move smoothly downward, thereby reducing the force on the return plate, avoiding damage to the return plate, ensuring the motor life, and expanding the application scenarios of the hydraulic motor.

[0015] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] Figure 1 This is a schematic diagram of a self-priming plunger structure according to an exemplary embodiment (showing normal operating state); Figure 2 This is a schematic diagram of a self-priming plunger according to an exemplary embodiment (showing the state of replenishing oil into the plunger cavity). Figure 3This is a schematic diagram of the structure of a plunger body according to an exemplary embodiment (showing the assembly state of the plunger body and the slipper). Figure 4 This is a schematic diagram illustrating the assembly of a cone valve core and a spring according to an exemplary embodiment; Figure 5 This is a schematic diagram of a hydraulic motor employing a plunger structure according to an exemplary embodiment (showing a conventional motor in use). Figure 6 This is a schematic diagram of a hydraulic motor employing a plunger structure according to an exemplary embodiment (showing the state in which the plunger structure replenishes the plunger cavity with oil from the motor housing when the oil in the motor port is insufficient). Figure 7 This is a schematic diagram illustrating the structure of a hydraulic motor as a drive device in the prior art, according to an exemplary embodiment. Figure 8 This is a schematic diagram of the structure of a hydraulic motor as a drive device in the prior art according to an exemplary embodiment (showing the state when the hydraulic motor is not working). Detailed Implementation

[0018] The following description and accompanying drawings fully illustrate specific embodiments described herein to enable those skilled in the art to practice them. Some embodiments may include or substitute parts and features of other embodiments. The scope of the embodiments herein encompasses the entire scope of the claims and all available equivalents thereof. Throughout this document, the terms “first,” “second,” etc., are used only to distinguish one element from another without requiring or implying any actual relationship or order between the elements. Indeed, a first element can also be referred to as a second element, and vice versa. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a structure, apparatus, or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a structure, apparatus, or device. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the structure, apparatus, or device that includes said element. The various embodiments described herein are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments; similar or identical parts between embodiments can be referred to interchangeably.

[0019] The terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used in this document to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. They are used solely for the convenience of describing the document and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description herein, unless otherwise specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two elements; they can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0020] In this document, unless otherwise stated, the term "multiple" means two or more.

[0021] In this article, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0022] In this article, the term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0023] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0024] Figure 7 The diagram illustrates the working state of a hydraulic motor as a drive device in the prior art. Pressurized oil enters from the inlet, passes through the side oil passage into the spring chamber, pushes the valve core 2 to the leftmost position, opens the oil passage, and then pressurized oil enters the plunger chamber, pushing the plunger 5 to slide downward along the inclined plane of the swashplate 8, thereby driving the cylinder 4 to rotate. The cylinder 4 drives the output shaft 10 to rotate, thus outputting speed and torque.

[0025] Figure 8The diagram illustrates the state of the hydraulic motor when it is not working. At this time, there is no pressure at the oil inlet, and the valve core 2 is in the neutral position under the action of the spring force. The oil passage from the oil inlet and outlet to the plunger chamber is cut off by the valve core, and the oil in the plunger chamber cannot enter or flow out, so the motor is in a locked state. At this time, when the output shaft 10 is subjected to pressure exceeding the motor's set pressure, in order to protect the cylinder from damage, the safety valve set by the motor will open, and the oil in the low-position plunger chamber will flow out from the safety valve and enter the high-position plunger chamber. The flow of oil will then allow the cylinder to rotate. However, at this time, due to some leakage from the valve core 2 and the high-pressure part of the cylinder, the oil flowing out of the low-position plunger chamber cannot all enter the high-position plunger chamber. The oil supply in the high-position plunger chamber is insufficient, and the plunger 5 cannot move downward smoothly. The return plate forces the plunger back to the low position. When the pulling force exceeds the force limit of the return plate, it will cause damage to the return plate.

[0026] To address the problem of return disc damage caused by insufficient oil in the plunger cavity, this application provides a self-priming plunger and a hydraulic motor employing this plunger structure.

[0027] Example 1

[0028] Figures 1-2 An embodiment of a self-priming plunger according to the present invention is shown.

[0029] The self-priming plunger includes: Piston body 5; The sliding shoe 7 is connected to one end of the plunger body 5 via a ball head-ball socket structure. The plunger body 5 contains a cone valve core 11 for opening, closing and sealing by cooperating with the interior of the plunger body 5 with a cone-shaped sealing surface, and a spring 12 for pushing the cone valve core 11 to reset.

[0030] As a specific implementation, the plunger body 5 is provided with a plunger cavity 5-1 inside for forming a sealing pair with the head of the cone valve core 11; A central through hole 5-2 for allowing pressurized oil to flow to the slipper 7 is provided axially at the bottom of the plunger body 5. A replenishment oil hole 5-3 is provided at the bottom of the plunger body 5 for allowing oil from the housing to enter the plunger cavity 5-1.

[0031] like Figure 3 As shown, specifically, the plunger cavity 5-1 has a first straight cylindrical section 5-1-1, a variable cross-section section 5-1-2, and a second straight cylindrical section 5-1-3, wherein the diameter of the first straight cylindrical section 5-1-1 is larger than the diameter of the second straight cylindrical section 5-1-3.

[0032] like Figure 4 As shown, in a specific implementation scheme, the cone valve core 11 includes: Valve core body 11-1; A valve core oil hole 11-2 for the flow of oil is provided axially on the valve core body 11-1.

[0033] The valve core body 11-1 has a spring cavity 11-3 inside for accommodating the spring.

[0034] Specifically, the bottom of the valve core body 11-1 has a conical sealing part, wherein the slope of the variable cross-section section is less than the slope of the conical sealing part. This design ensures that when two parts with different slopes come into contact, the contact point is a straight line, resulting in better sealing. The conical sealing part of the conical valve core cooperates with the second straight section to achieve opening, closing, and sealing.

[0035] Example 2 Based on Example 1, such as Figures 5-6 As shown, the present invention provides an embodiment of a hydraulic motor employing this plunger structure.

[0036] The hydraulic motor includes a valve body 1, a housing 9, an output shaft 10, and a cylinder 4. The valve body 1 is provided with an oil outlet and an oil inlet. One end of the oil outlet and the oil inlet are connected to an oil passage, and the other end of the oil passage is connected to the self-priming plunger of Embodiment 1.

[0037] The cylinder body 4 is located in the central core position of the hydraulic motor and is a key cavity component that houses the piston 5 and other actuators. The cylinder body 4 and the inner wall of the housing 9 usually have a fitting or sealing structure. Multiple self-priming pistons of Embodiment 1 are nested inside, and it is connected to the oil circuit system composed of the valve body 1, valve core 2, etc., to realize the intake and discharge of hydraulic oil in the cylinder body 4, providing the hydraulic power basis for the reciprocating motion of the piston 5.

[0038] The plungers 5 are evenly arranged in the plunger holes of the cylinder 4 along the circumference of the cylinder 4, and can reciprocate along the axis of the cylinder 4. The plungers 5 are connected to the slippers 7 by ball joints or other connection methods, and the other end is in contact with the swashplate 8. When the cylinder 4 rotates, the plungers 5 are pushed by the swashplate 8 to complete the reciprocating motion, converting hydraulic energy into mechanical energy.

[0039] In use, the oil enters the hydraulic motor through the oil inlet. After the valve body 1, valve core 2 and spring 3 control the opening and closing of the oil circuit, the oil flows into the cylinder 4. The plunger 5 in the cylinder 4 contacts the swashplate 8 under the action of the return plate 6 and the slipper 7. When working as a motor, the high-pressure oil enters and pushes the plunger 5 to move, thereby driving the cylinder 4 and the output shaft to rotate and output mechanical energy.

[0040] When the output shaft 10 drives the cylinder 4 to rotate, the oil inlet cannot provide enough oil. The tilt angle of the swashplate 8 causes the plunger 5 to reciprocate. However, because the cylinder 4 does not receive sufficient oil, the plunger 5 cannot slide smoothly along the inclined surface of the swashplate 8. Since the return plate remains parallel to the inclined surface of the swashplate 8, the return plate pulls the plunger component outwards. Due to insufficient oil inside, the plunger component cannot exit, causing damage to the return plate and leading to motor failure. This invention adds a cone valve sealing structure inside the plunger body. When the motor output shaft rotates passively and the oil supply at the inlet is insufficient, the cone valve core 11 seal automatically opens. The cone valve core 11 moves upwards to balance the oil volume inside the plunger cavity 5-1, preventing the plunger 5 from being unable to move downwards due to insufficient oil. The plunger body can move downwards smoothly, preventing damage to the return plate and ensuring the motor's lifespan during passive rotation. This expands the application scenarios of hydraulic motors.

[0041] like Figure 5 As shown, in the normal working state of the self-priming plunger, the pressure oil at the hydraulic motor inlet pushes the cone valve core 11 to the bottom. The cone valve core 11 acts as a seal, ensuring that the pressure inside the plunger cavity 5-1 is maintained, thereby allowing the hydraulic motor to generate speed and torque, enabling the hydraulic motor to work normally. During the process, the valve body 1, valve core 2, and spring 3 ensure the stability of oil circuit pressure and flow direction, while the housing 9 provides support and sealing for the internal parts. Figure 6 As shown, when the hydraulic motor is pulled backward, the oil in the housing enters the piston chamber 5-1 through the oil replenishment hole 5-3 to replenish the oil volume leaked from the high-pressure side of the hydraulic motor due to high pressure, ensuring that the piston 5 can move downward smoothly, eliminating the resistance of the piston 5 to the operation of the return plate, and avoiding damage to the motor.

[0042] This invention introduces the oil inside the housing into the plunger cavity, eliminating the damage to the return plate 6 caused by insufficient oil in the hydraulic motor plunger cavity, and has a simple structure.

[0043] This invention is not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this invention is limited only by the appended claims.

Claims

1. A self-priming plunger characterized by, Comprise: Plunger body (5); The plunger body (5) is provided with a conical valve core (11) for opening and closing and sealing with the plunger body (5) inner wall matched with conical sealing surface and spring (12) for pushing conical valve core (11) reset.

2. The self-priming piston of claim 1, wherein, The inside of the plunger body (5) is provided with a plunger cavity (5-1) for forming a sealing pair with the head of the conical valve core (11); The bottom of the plunger body (5) is provided with a center through hole (5-2) for flowing the pressure oil to the shoe (7); The bottom of the plunger body (5) is provided with a supplementary oil hole (5-3) for entering the oil in the shell (9) into the inside of the plunger cavity (5-1).

3. The self-priming piston of claim 2, wherein, The plunger cavity (5-1) has a first straight cylinder section (5-1-1), a variable cross-section section (5-1-2) and a second straight cylinder section (5-1-3); The diameter of the first straight cylinder section (5-1-1) is greater than the diameter of the second straight cylinder section (5-1-3).

4. The self-priming piston of claim 3, wherein, The bottom of the valve core body (11-1) has a conical sealing part, and the slope of the conical sealing part is greater than the slope of the variable cross-section section (5-1-2).

5. The self-priming piston of claim 1, wherein, The conical valve core (11) comprises: Valve core body (11-1); The valve core body (11-1) is provided with a valve core oil hole (11-2) for flowing oil axially; The inside of the valve core body (11-1) has a spring cavity (11-3) for accommodating the spring.

6. A hydraulic motor characterized by, The valve body (1), the shell (9), the output shaft (10) and the cylinder (4) are provided with oil outlet and oil inlet, one end of the oil outlet and the oil inlet is connected with the oil way, the other end of the oil way is communicated with the self-suction plunger of any one of claims 1-5.

7. The hydraulic motor of claim 6, wherein, When the self-suction plunger works normally, the pressure oil of the oil inlet pushes the conical valve core (11) to the bottom, the conical surface of the conical valve core (11) forms a seal with the plunger cavity (5-1), so that the inside of the plunger cavity (5-1) maintains pressure, and the pressure drives the hydraulic motor to work.

8. The hydraulic motor of claim 6, wherein, When the hydraulic motor is in passive rotation state, the oil in the shell (9) enters the plunger cavity (5-1) through the supplementary oil hole (5-3).

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