A bidirectional internal gear with gap compensation function

Abstract

The utility model discloses a bidirectional internal meshing gear with gap compensation function, include: input shaft drive's internal gear, with internal gear's external gear, be located in the internal gear and external gear between cavity's internal crescent board and two external crescent boards, internal crescent board's inner arc section is with internal gear's outer ring tooth and is set up, external crescent board is located on the outer arc section of internal crescent board, and the outer arc section of external crescent board is with external gear's inner ring tooth and is set up, the inner arc section of two external crescent boards all is equipped with a first lug, and the outer arc section of internal crescent board is equipped with two first recesses suitable for the embedding of first lug, and the outer peripheral wall of each first lug and the inner peripheral wall of first recess gap fit and exist the gap between the top surface of each first lug and the bottom surface of first recess and constitute the oil storage cavity of equivalent seal. The utility model has solved the technical problem that internal and external crescent board can directly contact and collide, and has reached the technical effect that the collision between crescent board is avoided.

Description

Technical Field

[0001] This utility model relates to the field of gear technology, specifically to a bidirectional internal meshing gear with clearance compensation function. Background Technology

[0002] An internal gear pump is a common type of positive displacement hydraulic pump. In an internal gear pump, the pump body and pump cover are connected by bolts to form a cavity. The pump cover has oil holes for oil inlet and outlet. A circular ring is installed inside the cavity, and an internal gear and an external gear are installed inside the circular ring. Distribution plates are provided on both sides of the internal and external gears. A crescent-shaped partition is provided between the internal and external gears. The crescent-shaped partition can be either fixed or floating.

[0003] The working principle of an internal gear pump is that the internal gear is located inside the external gear and rotates in mesh. The internal gear drives the external gear to rotate in the same direction. When one side of the gear disengages, the volume increases to form an oil suction chamber, and oil is drawn in from the oil inlet under negative pressure. When the other side of the gear engages, the volume decreases to form a pressure chamber, and the oil is squeezed out from the oil outlet. This achieves the functions of oil suction and oil pressure. The crescent-shaped baffle is used to achieve high-pressure sealing between the oil suction chamber and the oil pressure chamber.

[0004] In existing technologies, floating crescent-shaped baffles typically employ a structure with two crescent-shaped plates, inner and outer, which offer superior sealing performance, higher volumetric efficiency, and better pressure adaptability compared to a single crescent-shaped baffle. During operation, the oil pressure difference in the internal gear pump pushes the outer crescent-shaped plate closer to the inner crescent-shaped plate. Although an oil film exists between the two plates as a buffer, there is still a risk of direct contact and collision. Moreover, during startup, especially cold starts, an oil film cannot be quickly established between the two plates, making them prone to direct contact and collision. This direct collision can lead to wear on both plates, affecting their service life. Utility Model Content

[0005] This application provides a bidirectional internal meshing gear with clearance compensation function to avoid direct contact and collision between the inner and outer crescent plates.

[0006] This application provides a bidirectional internal meshing gear with clearance compensation function, comprising: an internal gear driven by an input shaft, an external gear meshing with the internal gear, and a crescent plate assembly disposed in the cavity between the internal gear and the external gear; the crescent plate assembly includes an inner crescent plate and two outer crescent plates, all of which are bent toward the internal gear; the inner arc segment of the inner crescent plate abuts against and slides with the outer ring teeth of the internal gear; the two outer crescent plates are circumferentially symmetrically disposed on the outer arc segment of the inner crescent plate, and the inner circumferential wall of each outer crescent plate is flush with the inner crescent plate. The outer peripheral walls of the toothed plates are all clearance-fitted, and the outer arc segments of the two outer crescent plates abut against and slide with the inner ring teeth of the external gear; the two outer crescent plates are circumferentially driven with the inner crescent plates; each of the inner arc segments of the two outer crescent plates is provided with a first protrusion, and the outer arc segment of the inner crescent plate is provided with two first recesses suitable for the first protrusions to be inserted; the outer peripheral wall of each first protrusion is clearance-fitted with the inner peripheral wall of the first recess, and there is a gap between the top surface of each first protrusion and the bottom surface of the first recess to form an equivalent sealed oil storage cavity.

[0007] By adopting the above technical solution, a first protrusion and a first recess are provided between the outer crescent plate and the inner crescent plate. During the operation of the outer crescent plate and the inner crescent plate, the first protrusion and the first recess cooperate to form an equivalent sealed oil storage cavity. The oil in the oil storage cavity slowly overflows through the gap between the first protrusion and the first recess, which plays a damping role in slowing down the movement and preventing the inner and outer crescent plates from directly contacting and colliding. At the same time, during the start-up phase or cold start, the relative compression of the inner and outer crescent plates causes the oil in the oil storage cavity to overflow and form an oil film between the inner and outer crescent plates, avoiding direct contact between the surfaces of the inner and outer crescent plates.

[0008] Preferably, each first protrusion is a cuboid protrusion with a square cross-section, and each first recess is a cuboid groove with a square cross-section.

[0009] By adopting the above technical solution, the first protrusion and the first depression, which have a square cross-section, ensure that when the inner and outer crescent plates are squeezed, the oil in the oil storage cavity overflows evenly to the surrounding area, ensuring the uniform establishment of the oil film.

[0010] Preferably, each outer crescent plate has a second protrusion on the inner arc segment at one end of the circumferential inner side. The second protrusion extends axially, and the outer arc segment of the inner crescent plate has two axially penetrating first grooves. Each second protrusion is embedded in the corresponding first groove and contacts the inner wall surface of the first groove.

[0011] By adopting the above technical solution, a second protrusion is set in the inner arc section of each outer crescent plate near the positioning shaft, which is embedded in the first groove of the inner crescent plate. Through surface contact, a stable circumferential transmission support is provided for the outer crescent plate, avoiding vibration or displacement of the outer crescent plate under the action of high pressure oil or gear meshing force, and further improving the stability of the inner and outer crescent plates in operation.

[0012] Preferably, the circumferential outer wall of each first groove is fitted with the surface clearance of the corresponding second protrusion to form a first oil passage cavity.

[0013] By adopting the above technical solution, a first oil passage cavity is formed by a gap fit between the first groove and the second protrusion on the side away from the positioning axis. By utilizing the structural gap, a channel for free flow of oil is provided while ensuring the support strength. At the same time, the first oil passage cavity plays a certain role in pressure buffering, improving the adaptability of the inner and outer crescent plates to oil pressure fluctuations.

[0014] Preferably, a first inclined surface is provided on the inner arc segment at the outer end of each of the two outer crescent plates, and two second inclined surfaces are provided on the outer arc segment of the inner crescent plate. The two second inclined surfaces abut against the corresponding first inclined surfaces. Each second inclined surface is inclined towards the end of the inner crescent plate in the direction of the outer arc segment of the inner crescent plate, and the inclination direction of each first inclined surface is the same as the inclination direction of the second inclined surface on the same side.

[0015] By adopting the above technical solution, a first inclined surface and a second inclined surface that match each other are respectively set at the end of the outer crescent plate away from the positioning shaft and the corresponding position of the inner crescent plate. Through surface contact, when the inner and outer crescent plates interact and move toward the gear, the gap between the crescent plate and the gear is quickly reduced, the oil pressure is built up, and the overall sealing reliability of the crescent plate assembly is improved.

[0016] Preferably, each outer crescent plate is provided with a third groove near the first inclined surface, each third groove axially penetrates the outer crescent plate, and each third groove and the outer peripheral wall of the inner crescent plate form an axially penetrating second oil passage cavity.

[0017] By adopting the above technical solution, a third groove is set on the inner arc segment of the outer crescent plate. The third groove and the outer arc segment of the inner crescent plate cooperate to form an axially penetrating second oil passage. While ensuring the support strength, it provides a channel for free flow of oil. At the same time, the second oil passage plays a certain role in pressure buffering, improving the adaptability of the inner and outer crescent plates to oil pressure fluctuations.

[0018] Preferably, a bidirectional internal meshing gear with clearance compensation function further includes a cover body, on which two oil holes are symmetrically provided, and two second oil passage chambers are respectively located at the two oil holes.

[0019] By adopting the above technical solution, the two oil passage chambers are located at the two oil holes respectively, which facilitates the direct entry and exit of oil from the oil holes into the second oil passage chamber when oil is sucked or discharged, so that the oil can quickly enter between the inner and outer crescent plates and improve the coverage speed of the oil.

[0020] Preferably, two circumferentially extending oil guide grooves are provided on both sides of the inner crescent plate, and each oil guide groove connects the first oil passage chamber and the second oil passage chamber.

[0021] By adopting the above technical solution, oil guide grooves are set on both sides of the inner crescent plate, and these oil guide grooves are connected to the first oil passage and the second oil passage respectively, thus constructing an efficient and complete oil lubrication path and improving the coverage speed of the oil.

[0022] Preferably, a bidirectional internal meshing gear with clearance compensation function further includes a housing, an external gear rotatably disposed within the housing, a positioning shaft fixedly disposed within the housing, the positioning shaft axially penetrating an inner crescent plate, the positioning shaft circumferentially and radially limiting the inner crescent plate, and the inner crescent plate being rotatably connected to the positioning shaft.

[0023] By adopting the above technical solution, an axial positioning shaft is fixed inside the housing and passes through the inner crescent plate. This can precisely constrain the circumferential and radial positions of the inner crescent plate during operation, preventing the inner crescent plate from tilting or rotating. This ensures stable contact between the inner crescent plate and the outer ring teeth of the internal gear, thereby improving the overall sealing performance and operational stability.

[0024] Preferably, the inner crescent plate has a second groove that extends axially through the middle of the outer arc segment, and the positioning shaft is located in the second groove.

[0025] By adopting the above technical solution, a second groove that penetrates axially is set in the middle of the outer arc segment of the inner crescent plate, which makes it easy to install the inner crescent plate into the cavity between the inner gear and the outer gear during assembly, and the simple structure is easy to manufacture.

[0026] One or more technical solutions provided in this application have at least the following technical effects or advantages: 1. A first protrusion and a first recess are provided between the outer crescent plate and the inner crescent plate. During the operation of the outer crescent plate and the inner crescent plate, the first protrusion and the first recess cooperate to form an equivalent sealed oil storage cavity. The oil in the oil storage cavity slowly overflows through the gap between the first protrusion and the first recess, which plays a damping role in reducing the movement and preventing the inner and outer crescent plates from directly contacting and colliding. At the same time, during the start-up phase or cold start, the relative compression of the inner and outer crescent plates causes the oil in the oil storage cavity to overflow and form an oil film between the inner and outer crescent plates, avoiding direct contact between the surfaces of the inner and outer crescent plates. 2. The first protrusion and the first depression, which have a square cross-section, ensure that when the inner and outer crescent plates are squeezed, the oil in the oil storage cavity overflows evenly to the surrounding area, ensuring the uniform establishment of the oil film. 3. A second protrusion is set on the inner arc section of each outer crescent plate near the positioning shaft, which is embedded in the first groove of the inner crescent plate. Through surface contact, it provides stable circumferential transmission support for the outer crescent plate, avoids vibration or displacement of the outer crescent plate under the action of high pressure oil or gear meshing force, and further improves the stability of the inner and outer crescent plates in operation. 4. The first groove on the side away from the positioning axis forms a clearance fit with the second protrusion to form the first oil passage cavity. By utilizing the structural clearance, a channel for free flow of oil is provided while ensuring the support strength. At the same time, the first oil passage cavity plays a certain role in pressure buffering, improving the adaptability of the inner and outer crescent plates to oil pressure fluctuations. 5. Matching first and second inclined surfaces are respectively set at the end of the outer crescent plate away from the positioning shaft and the corresponding position of the inner crescent plate. Through surface contact, when the inner and outer crescent plates interact and move towards the gear, the gap between the crescent plate and the gear is quickly reduced, the oil pressure is accelerated, and the overall sealing reliability of the crescent plate assembly is improved. 6. A third groove is set on the inner arc segment of the outer crescent plate. The third groove and the outer arc segment of the inner crescent plate cooperate to form an axially penetrating second oil passage. While ensuring the support strength, it provides a channel for free flow of oil. At the same time, the second oil passage plays a certain role in pressure buffering and improves the adaptability of the inner and outer crescent plates to oil pressure fluctuations. 7. Oil guide grooves are provided on both sides of the inner crescent plate, and these oil guide grooves are connected to the first oil passage and the second oil passage respectively, thus constructing an efficient and complete oil lubrication path and improving the coverage speed of the oil. 8. An axial positioning shaft is fixed inside the housing and passes through the inner crescent plate. This can precisely constrain the circumferential and radial position of the inner crescent plate during operation, preventing the inner crescent plate from tilting or rotating. This ensures stable contact between the inner crescent plate and the outer ring teeth of the internal gear, thereby improving the overall sealing performance and operational stability. A second axially penetrating groove is set in the middle of the outer arc section of the inner crescent plate, which facilitates the installation of the inner crescent plate into the cavity between the internal gear and the external gear during assembly. The simple structure is easy to manufacture. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 Axonometric drawing of a bidirectional internal meshing gear with clearance compensation function provided for this application; Figure 2 A front view of a crescent plate assembly of a bidirectional internal meshing gear with clearance compensation function provided in this application; Figure 3 An isometric view of the outer crescent plate of a bidirectional internal meshing gear with clearance compensation function provided in this application; Figure 4An isometric view of the inner crescent plate of a bidirectional internal meshing gear with clearance compensation function provided in this application; Figure 5 An exploded schematic diagram of a bidirectional internal meshing gear with clearance compensation function provided in this application.

[0029] Explanation of reference numerals in the attached drawings: 1. Internal gear; 2. External gear; 3. Inner crescent plate; 31. First recess; 32. First groove; 33. Second inclined surface; 34. Second groove; 4. Outer crescent plate; 41. First protrusion; 42. Second protrusion; 43. First inclined surface; 44. Third groove; 5. Positioning shaft; 6. First oil passage cavity; 7. Second oil passage cavity; 8. Oil guide groove; 9. Housing; 91. Cover; 911. Oil hole; 92. First distribution plate; 93. Second distribution plate; 94. Circular ring. Detailed Implementation

[0030] This application provides a bidirectional internal meshing gear with clearance compensation function to avoid direct contact and collision between the inner and outer crescent plates.

[0031] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0032] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0033] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and 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 this utility model.

[0034] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0035] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0036] like Figure 5 As shown, the internal gear pump includes a housing 9 and a cover 91. The housing 9 and the cover 91 are connected by bolts to form a cavity. Two oil holes 911 are symmetrically provided on the cover 91 and communicate with the cavity. A second distribution plate 93 is provided at the bottom of the cavity. A circular ring 94 is installed on the inner wall of the cavity. A rotatable external gear 2 is installed in the circular ring 94. The internal gear 1 and the external gear 2 are meshed and assembled. The lower end face of the internal and external gears 2 is in contact with the second distribution plate 93, and the upper end face of the internal and external gears 2 is in contact with the first distribution plate 92. The other side of the first distribution plate 92 is in contact with the cover 91. A crescent plate assembly is installed in the cavity between the internal gear 1 and the external gear 2. An axially extending positioning shaft 5 is fixed in the cavity of the housing 9 to limit the inner crescent plate 3. Example

[0037] like Figures 1 to 4 The embodiment of this application provides a bidirectional internal meshing gear with backlash compensation function, including: an internal gear 1 driven by an input shaft, an external gear 2 meshing with the internal gear 1, and a crescent plate assembly disposed in the cavity between the internal gear 1 and the external gear 2; the crescent plate assembly includes an inner crescent plate 3 and two outer crescent plates 4, all of which are bent toward the internal gear 1; the inner arc segment of the inner crescent plate 3 abuts against the outer ring teeth of the internal gear 1; the two outer crescent plates 4 are circumferentially spaced apart from the inner crescent plate. On the outer arc segment of the toothed plate 3, and the outer arc segments of the two outer crescent plates 4 abut against the inner ring teeth of the external gear 2; each of the two outer crescent plates 4 has a first protrusion 41 on its inner arc segment, and the outer arc segment of the inner crescent plate 3 has two first recesses 31 suitable for the first protrusion 41 to be inserted. The outer peripheral wall of each first protrusion 41 and the inner peripheral wall of the first recess 31 are in clearance fit, and there is a gap between the top surface of each first protrusion 41 and the bottom surface of the first recess 31 to form an equivalent sealed oil storage cavity.

[0038] In a preferred embodiment provided in this application, the internal gear 1 is driven by an input shaft and meshes with the external gear 2. A floating crescent plate assembly is disposed in the cavity between the internal gear 1 and the external gear 2. The crescent plate assembly consists of an inner crescent plate 3 and two independent outer crescent plates 4, both of which are bent toward the internal gear 1. The inner arc segment of the inner crescent plate 3 tightly abuts against the outer ring tooth tip of the internal gear 1, forming a radial seal. The two outer crescent plates 4 are circumferentially symmetrically distributed on both sides of the outer arc segment of the inner crescent plate 3, and the outer arc segments of both outer crescent plates 4 abut against the inner ring tooth tip of the external gear 2. The outer arc segment is the outer peripheral wall, and the inner arc segment is the inner peripheral wall.

[0039] The inner crescent plate 3 has a second through-groove 34 at the center of its outer arc segment for assembly with the positioning shaft 5. The outer arc segment of the inner crescent plate 3 is machined with two square first recesses 31 symmetrical to the positioning shaft 5. Each outer crescent plate 4 has a rectangular first protrusion 41 with a square cross-section at its center on its inner arc segment. The first protrusion 41 is embedded in the corresponding first recess 31. Each first recess 31 is a rectangular groove with a square cross-section. The outer peripheral wall of the first protrusion 41 has a slight clearance fit with the inner peripheral wall of the first recess 31, and there is a gap between the top surface of each first protrusion 41 and the bottom surface of each first recess 31, thus forming an equivalent sealed oil reservoir. This oil reservoir can store lubricating oil, allowing for rapid oil film buffering during pump startup and preventing direct collision between the inner and outer crescent plates 4.

[0040] Each outer crescent plate 4 has a second protrusion 42 at one end near the positioning shaft 5. The two second protrusions 42 are respectively embedded in two axially penetrating first grooves 32 symmetrically arranged on the outer arc segment of the inner crescent plate 3. The outer crescent plate 4 achieves radial limitation through the wall contact between the second protrusion 42 and the first groove 32. The side of the first groove 32 away from the positioning shaft 5 maintains a gap with the second protrusion 42 to form a first oil passage 6, which facilitates the flow of lubricating oil.

[0041] At the end of the outer crescent plate 4 away from the positioning shaft 5, the inner arc segment is machined with a first inclined surface 43, and the corresponding position of the inner crescent plate 3 is provided with a second inclined surface 33. The first inclined surface 43 and the second inclined surface 33 provide oblique support through surface contact. The inclination direction of the second inclined surface 33 is from the end of the outer arc segment of the inner crescent plate 3 to the center of the inner arc segment. The inclination direction of the first inclined surface 43 is in the same direction as the second inclined surface 33. The inner arc segment of the outer crescent plate 4 is provided with a third groove 44 near the first inclined surface 43. The third groove 44 cooperates with the outer peripheral wall of the inner crescent plate to form an axially penetrating second oil passage 7, which facilitates the axial circulation of lubricating oil. The two second oil passage 7 are located at the two oil holes 911 respectively, which facilitates the direct entry and exit of oil into the second oil passage 7 when oil is sucked in and discharged.

[0042] Two sets of oil guide grooves 8 are provided on each side end face of the inner crescent plate 3. Each set is located in the area covered by an outer crescent plate 4. The oil guide grooves 8 are connected to the first oil passage 6 and the second oil passage 7 to form a complete lubrication path.

[0043] During startup, the input shaft drives the internal gear 1 to rotate, which in turn drives the external gear 2 to rotate through gear meshing. One gear disengages, increasing the volume to form an oil suction chamber, drawing oil in through an oil hole 911 under negative pressure. The other gear engages, decreasing the volume to form a pressure chamber, where the oil is squeezed out through another oil hole 911. Simultaneously, since both the internal gear 1 and the external gear 2 abut against the crescent plate assembly, the rotation of the gears drives the crescent plate assembly to move in the same direction. At the same time, the oil pressure generated between the oil suction chamber and the pressure chamber pushes the external crescent plate 4 closer to the internal crescent plate 3. At this time, the lubricating oil pre-stored in the oil storage chamber passes through the gap. The overflow forms an oil film to prevent direct contact and collision between the inner and outer crescent plates 4. During operation, the lubricating oil continuously lubricates all contact surfaces through the first oil passage 6, the second oil passage 7, and the oil guide groove 8. The first oil passage 6 and the second oil passage 7 quickly establish a uniform and stable oil pressure. Under the action of the oil pressure, the outer crescent plate 4 quickly approaches the inner crescent plate 3 to form an equivalent sealing surface. When the outer crescent plate 4 approaches the inner crescent plate 3, the oil in the oil storage cavity will slowly overflow through the gap, which plays a damping role in slowing down the movement. The positioning shaft 5 is used to maintain the stability of the inner crescent plate 3, so that it remains stable under gear rotation and oil pressure fluctuations.

[0044] In this embodiment, by providing a first protrusion 41 and a first recess 31 that cooperate with each other between the outer crescent plate 4 and the inner crescent plate 3, during the operation of the outer crescent plate 4 and the inner crescent plate 3, the first protrusion 41 and the first recess 31 cooperate to form an equivalent sealed oil storage cavity. The oil in the oil storage cavity slowly overflows through the gap between the first protrusion 41 and the first recess 31, which plays a damping role in slowing down the movement and preventing the inner and outer crescent plates 4 from directly contacting and colliding. At the same time, during the start-up phase or cold start, the relative compression of the inner and outer crescent plates 4 causes the oil in the oil storage cavity to overflow and form an oil film, avoiding direct contact between the surfaces of the inner and outer crescent plates 4.

[0045] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, specific embodiments have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims can be performed in a different order than that shown in the embodiments and still achieve the desired result. Additionally, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0046] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0047] This specification and accompanying drawings are merely illustrative examples of this application and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Therefore, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A bidirectional internal meshing gear with backlash compensation function, characterized in that: The system includes an internal gear (1) driven by an input shaft, an external gear (2) meshing with the internal gear (1), and a crescent plate assembly disposed in the cavity between the internal gear (1) and the external gear (2). The crescent plate assembly includes an inner crescent plate (3) and two outer crescent plates (4), both of which are bent toward the internal gear (1). The inner arc segment of the inner crescent plate (3) abuts against and slides with the outer ring teeth of the internal gear (1). The two outer crescent plates (4) are circumferentially symmetrically disposed on the outer arc segment of the inner crescent plate (3), and the inner circumferential wall of each outer crescent plate (4) is clearance-fitted with the outer circumferential wall of the inner crescent plate (3). The outer arc segments of the two outer crescent plates (4) abut against and slide with the inner ring teeth of the outer gear (2); the two outer crescent plates (4) are circumferentially driven with the inner crescent plate (3); a first protrusion (41) is provided on the inner arc segment of the two outer crescent plates (4), and two first recesses (31) suitable for the first protrusion (41) to be embedded are provided on the outer arc segment of the inner crescent plate (3). The outer peripheral wall of each first protrusion (41) is clearance-fitted with the inner peripheral wall of the first recess (31), and there is a gap between the top surface of each first protrusion (41) and the bottom surface of the first recess (31) to form an equivalent sealed oil storage cavity.

2. The bidirectional internal meshing gear with clearance compensation function according to claim 1, characterized in that, Each of the first protrusions (41) is a cuboid protrusion with a square cross-section, and each of the first recesses (31) is a cuboid groove with a square cross-section.

3. A bidirectional internal meshing gear with clearance compensation function according to claim 1, characterized in that, Each of the outer crescent plates (4) has a second protrusion (42) on the inner arc segment at one end of the circumferential inner side. The second protrusion (42) extends axially. The outer arc segment of the inner crescent plate (3) has two axially penetrating first grooves (32). Each second protrusion (42) is embedded in the corresponding first groove (32) and contacts the inner wall surface of the first groove (32).

4. A bidirectional internal meshing gear with clearance compensation function according to claim 3, characterized in that, Each of the first grooves (32) has its circumferential outer wall fitted with the surface clearance of the corresponding second protrusion (42) to form a first oil passage cavity (6).

5. A bidirectional internal meshing gear with clearance compensation function according to claim 4, characterized in that, Each of the two outer crescent plates (4) has a first inclined surface (43) on the inner arc segment at one end of the circumferential outer side, and the inner crescent plate (3) has two second inclined surfaces (33) on the outer arc segment. The two second inclined surfaces (33) abut against the corresponding first inclined surfaces (43). Each second inclined surface (33) is inclined towards the end of the inner crescent plate (3) in the direction of the outer arc segment of the inner crescent plate (3). The inclination direction of each first inclined surface (43) is the same as the inclination direction of the second inclined surface (33) on the same side.

6. A bidirectional internal meshing gear with clearance compensation function according to claim 5, characterized in that, Each of the outer crescent plates (4) is provided with a third groove (44) near the first inclined surface (43). Each of the third grooves (44) axially penetrates the outer crescent plate (4). Each of the third grooves (44) and the outer peripheral wall of the inner crescent plate (3) form an axially penetrating second oil passage cavity (7).

7. A bidirectional internal meshing gear with clearance compensation function according to claim 6, characterized in that, It also includes a cover (91), on which two oil holes (911) are symmetrically provided, and two second oil passage chambers (7) are located at the two oil holes (911) respectively.

8. A bidirectional internal meshing gear with clearance compensation function according to claim 6, characterized in that, Two circumferentially extending oil guide grooves (8) are provided on both sides of the inner crescent plate (3), and each of the oil guide grooves (8) connects the first oil passage (6) and the second oil passage (7).

9. A bidirectional internal meshing gear with clearance compensation function according to claim 1, characterized in that, It also includes a housing (9), the external gear (2) is rotatably disposed in the housing (9), a positioning shaft (5) is fixedly disposed in the housing (9), the positioning shaft (5) axially passes through the inner crescent plate (3), the positioning shaft (5) circumferentially and radially limits the inner crescent plate (3), and the inner crescent plate (3) is rotatably connected to the positioning shaft (5).

10. A bidirectional internal meshing gear with clearance compensation function according to claim 9, characterized in that, The inner crescent plate (3) has a second groove (34) that runs through the middle of the outer arc segment, and the positioning shaft (5) is located in the second groove (34).

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