A cycloid pump and a shock absorber

Abstract

The present invention discloses a cycloid pump and a shock absorber. The cycloid pump includes a gear set, and there is a chamber for oil suction and oil discharge inside the gear set. A first oil suction space communicating with the chamber is provided on the first side of the gear set, and a second oil suction space communicating with the chamber is provided on the second side of the gear set. The gear set is provided with a first oil passage communicating the first oil suction space and the second oil suction space. The oil in the first oil suction space can be introduced into the second oil suction space through the first oil passage. When the gear set sucks oil, it can suck oil from the first oil suction space and the second oil suction space into the chamber. The present invention can achieve double-sided oil suction of the cycloid pump, greatly enhance the oil suction capacity of the cycloid pump, greatly reduce the cavitation phenomenon caused by the oil during the flow process, and reduce vibration and noise. Moreover, compared with the conventional method of achieving double-sided oil suction by increasing the oil circuit, the present invention greatly simplifies the structure of the cycloid pump and the hydraulic system.

Description

Technical Field

[0001] The present invention relates to a hydraulic pump, and more particularly to a cycloid pump and a shock absorber. Background Art

[0002] The cycloid pump is one of the relatively common hydraulic pumps at present. It includes an inner gear and an outer gear. The inner gear has racks extending outward. The inner gear is coaxially connected to the output shaft of the motor and rotates synchronously with the output shaft of the motor under the drive of the motor. The outer gear is sleeved outside the inner gear and has racks extending inward. The racks of the outer gear and the inner gear can be partially engaged. During the continuous meshing and tooth disengaging process of the inner gear and the outer gear, the chamber formed between the inner gear and the outer gear is continuously compressed and enlarged, thereby realizing oil suction and oil discharge.

[0003] During the operation of the cycloid pump, the pressure in the oil suction chamber (the chamber between the inner gear and the outer gear) decreases. When the pressure is lower than the air separation pressure, the air dissolved in the oil separates out to form cavitation bubbles. When the bubbles move to a region with a higher pressure along with the liquid flow, they will quickly burst, thereby causing local hydraulic shock, generating vibration and noise, and causing serious damage to the pump body. Cavitation is a unique property of fluids, and this phenomenon is more obvious in high-speed rotor pumps.

[0004] In order to improve the cavitation characteristics of high-speed rotor pumps, the existing cycloid pumps are designed to be flat (the tooth thickness of the cycloid pump / the outer diameter of the outer gear's addendum circle is less than 0.5), or additional oil passages are added on both sides of the oil distribution plate to enhance the oil suction capacity of the pump. However, this design significantly increases the volume of the pump and occupies space. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a cycloid pump and a shock absorber in view of the above-mentioned defects of the prior art.

[0006] The technical solution adopted by the present invention to solve its technical problems is to construct a cycloid pump including a gear set. The gear set has a chamber for oil suction and oil discharge. A first oil suction space communicating with the chamber is provided on the first side of the gear set. A second oil suction space communicating with the chamber is provided on the second side of the gear set opposite to the first side. The gear set is provided with a first oil passage communicating the first oil suction space and the second oil suction space. The oil in the first oil suction space can be introduced into the second oil suction space through the first oil passage. When the gear set sucks oil, it can suck oil from the first oil suction space and the second oil suction space into the chamber.

[0007] Preferably, the gear set is composed of an inner gear and an outer gear. The outer gear is sleeved outside the inner gear. The chamber is formed between the inner gear and the outer gear. At least one of the outer gear and / or the inner gear is provided with the first oil passage.

[0008] Preferably, racks extending outward are formed on the outer peripheral surface of the internal gear, racks extending inward are formed on the inner peripheral surface of the external gear, and the first oil passage is provided in some or all of the racks of the external gear and / or the internal gear.

[0009] Preferably, the first oil passage is a through hole parallel to the central axis of the gear set.

[0010] Preferably, the cycloid pump further includes a partition plate, a motor for driving the gear set to rotate, and a first oil area, a second oil area, and a third oil area. Among them: the first oil area is composed of the first oil suction space and the first second oil suction space facing each other, the second oil area is composed of the second first oil suction space and the second second oil suction space facing each other, the space where the motor is located is the third oil area, the second oil area is located on the first side of the partition plate, the third oil area is located on the second side of the partition plate, and a second oil passage communicating the second oil area and the third oil area is provided on the partition plate.

[0011] Preferably, the partition plate is a circular plate, and a strip-shaped gap extending along its radial direction is provided on the circular plate to form the second oil passage.

[0012] Preferably, the partition plate is a circular plate, and an arc-shaped gap is provided on the circular plate to form the second oil passage.

[0013] Preferably, the width dimension of the arc-shaped gap is 0.1 mm to 1 mm.

[0014] On the other hand, the present invention also constructs a shock absorber, including the cycloid pump, a hydraulic pipeline, and an execution unit as described in any one of the preceding items. The cycloid pump and the execution unit are communicated through the hydraulic pipeline, and the cycloid pump realizes the driving action of the execution unit through the oil suction and oil discharge actions.

[0015] The cycloid pump and the shock absorber of the present invention have the following beneficial effects: a first oil passage communicating the first oil suction space and the second oil suction space is provided on the gear set to realize double-sided oil suction of the cycloid pump, greatly enhancing the oil suction capacity of the cycloid pump. When the cycloid pump operates at high speed, the oil delivery capacity is improved, enabling the execution unit of the shock absorber with this cycloid pump to respond quickly. Through double-sided oil suction, the cavitation phenomenon caused by the flowing oil is greatly reduced, and the vibration and noise are reduced; moreover, the present invention realizes double-sided oil suction only by opening the first oil passage, which greatly simplifies the structure of the cycloid pump and the hydraulic system compared with the conventional method of realizing double-sided oil suction by increasing the oil circuit. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings:

[0017] Figure 1 is a sectional view of the cycloid pump of the present invention along the length direction of the motor output shaft;

[0018] Figure 2 is a longitudinal sectional view of the gear set;

[0019] Figure 3 is a three-dimensional structure diagram of the gear set;

[0020] Figure 4 is a sectional view A-A of the gear set;

[0021] Figure 5 is a sectional view of the gear set in a traditional cycloid pump. Detailed implementation manners

[0022] To facilitate the understanding of the present invention, the following will describe the present invention more comprehensively with reference to the relevant drawings. The typical embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0023] It should be noted that the terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0024] The ordinal terms such as "first", "second", etc. used in this specification can be used to describe various components, but these components are not limited by these terms. The purpose of using these terms is only to distinguish one component from other components. For example, without departing from the scope of the claims of the present invention, the first component can be named the second component, and similarly, the second component can also be named the first component. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0025] The general idea of the present invention is as follows: An oil suction space communicating with the chambers of the gear set of the cycloid pump is added on the other side of the gear set of the cycloid pump. At the same time, an oil passage is provided on the gear set to communicate the oil suction spaces on both sides of the gear set itself. The oil in the oil suction spaces on both sides of the gear set can flow through the oil passage. In this way, it can be ensured that there is oil in the oil suction spaces on both sides of the gear set. When the gear set sucks oil, it can suck the oil from the oil suction spaces on both sides into the chamber, realizing double-sided oil suction. When the cycloid pump operates at a high speed, the oil delivery capacity is improved, so that the actuator unit of the shock absorber with the cycloid pump responds quickly. Through double-sided oil suction, the cavitation phenomenon caused by the oil flow in the process is greatly reduced, and the vibration and noise are reduced. Moreover, compared with the conventional method of realizing double-sided oil suction by increasing the oil circuit, the structure of the cycloid pump and the hydraulic system are greatly simplified.

[0026] To better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments. It should be understood that the specific features in the embodiments of the present invention and the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. Without conflict, the technical features in the embodiments of the present invention and the embodiments can be combined with each other.

[0027] Refer to Figure 1-2 , in a specific embodiment of the present invention, the cycloid pump includes: a gear set 1 and a motor 2 located in the oil area. The gear set 1 includes an opposite first side, namely Figure 1 the upper side in the middle and a second side, namely Figure 1 the lower side in the middle. The body of the motor 2 is arranged on the second side of the gear set 1, and the motor 2 is used to drive the gear set 1 to rotate to realize oil suction and oil discharge.

[0028] The gear set 1 has a chamber 10 for oil suction and oil discharge. Refer to Figure 2 , specifically, the gear set 1 is composed of an inner gear 11 and an outer gear 12. The inner gear 11 is coaxially connected with the motor output shaft 21 and rotates synchronously with the motor output shaft 21 under the drive of the motor 2. The outer gear 12 is sleeved outside the inner gear 11. The chamber 10 is formed between the outer peripheral surface of the inner gear 11 and the inner peripheral surface of the outer gear 12. During the continuous meshing and disengagement of the inner gear 11 and the outer gear 12, the space of the chamber 10 is continuously squeezed and enlarged, so as to realize oil discharge and oil suction.

[0029] Among them, in combination with Figure 1 , 4, on the first side of the gear set 1, there are two first oil suction spaces 3 and 4 communicating with the chamber 10, and these two first oil suction spaces 3 and 4 are specifically provided by an oil suction disc. To achieve double-sided oil suction, in the embodiment of the present invention, two second oil suction spaces 3' and 4' communicating with the chamber 10 are reserved on the second side of the gear set 1 opposite to the first side. The number of the second oil suction spaces 3' and 4' is also two, which corresponds one-to-one with the two first oil suction spaces 3 and 4. The shapes of the second oil suction spaces 3' and 4' are similar to those of the first oil suction spaces 3 and 4. That is to say, there are two oil suction spaces on both the upper and lower sides of the gear set 1. The gear set 1 is provided with a first oil passage 5 communicating the first oil suction spaces 3 and 4 with the second oil suction spaces 3' and 4'. The oil in the first oil suction spaces 3 and 4 can be introduced into the second oil suction spaces 3' and 4' via the first oil passage 5, and the oil is sucked into the chamber 10 from the first oil suction spaces 3 and 4 on the first side and the second oil suction spaces 3' and 4' on the second side respectively through the space change between the internal gear 11 and the external gear 12, so as to achieve double-sided oil suction of the cycloid pump. If the gear set 1 rotates forward, it sucks oil from Figure 1 the first oil suction space 3 on the left side and the second oil suction space 3' on the left side in Figure 1 , and vice versa. If the gear set 1 rotates reversely, it sucks oil from

[0030] Specifically, referring to Figure 5 , in a traditional cycloid pump, there is almost no space on the second side of the gear set. However, in this embodiment, the second side of the gear set 1 reserves the second oil suction spaces 3' and 4'. For example, referring to Figure 3-4 , in the embodiment of the present invention, slots are opened in the area of the cycloid pump housing 6 facing the gear set 1, so as to reserve two second oil suction spaces 3' and 4'. Of course, slots can also be opened in the gear set 1 to reserve space. No matter which method is adopted, as long as the second oil suction spaces 3' and 4' communicating with the chamber 10 are reserved on the second side of the gear set 1.

[0031] While reserving the second oil suction spaces 3' and 4', a first oil passage 5 also needs to be opened on the gear set 1. Since the gear set 1 is composed of an internal gear 11 and an external gear 12, theoretically, the first oil passage 5 can be opened on the external gear 12, or on the internal gear 11, or on both the internal gear 11 and the external gear 12 at the same time. Of course, the number of the first oil passages 5 can also be selected according to the situation. Whether the first oil passage 5 is provided on the external gear 12 or the internal gear 11, it is necessary to ensure that the first oil passage 5 communicates the first oil suction spaces 3 and 4 with the second oil suction spaces 3' and 4'. Referring to Figure 1 , considering the current positions of the first oil suction spaces 3 and 4, it is recommended to preferably open the first oil passage 5 on the external gear 12.

[0032] More specifically, racks extending outward are formed on the outer peripheral surface of the internal gear 11, and racks extending inward are formed on the inner peripheral surface of the external gear 12. In this embodiment, a first oil passage 5 is provided in each rack of the external gear 12. Similarly, if the first oil passage 5 is provided in the internal gear 11, it is also recommended to provide the first oil passage 5 in the racks of the internal gear 11, so that the number of the first oil passages 5 can be ensured, and the first oil passages 5 are evenly distributed, ensuring that when the gear set 1 stays at any position, there will be a first oil passage 5 communicating with the first oil suction spaces 3, 4 and the second oil suction spaces 3', 4'. Of course, in other embodiments, the first oil passage 5 can also be provided at non-rack positions of the external gear 12 and the internal gear 11, as long as the oil flow from the first side to the second side of the gear set 1 can be realized.

[0033] It should be noted that the shape of the first oil passage 5 is not limited. In this embodiment, the first oil passage 5 is a circular through hole parallel to the central axis of the gear set 1.

[0034] Since the motor 2 is generally immersed in the oil, the heat dissipation efficiency of the motor 2 can be improved through the oil circulation. However, during the high-speed operation of the internal gear 11 and the external gear 12 of the cycloid pump, the oil pressure changes greatly. Since the motor 2 is immersed in the oil, the change in the oil pressure will generate a unilateral extrusion force on the rotor of the motor 2, affecting the balance of the output shaft 21 of the motor, thereby causing vibration or noise. Therefore, in order to further improve the stability of the cycloid pump according to the embodiment of the present invention, referring to Figure 1 , preferably, in the embodiment of the present invention, the cycloid pump further includes a partition 7 and a first oil area 101, a second oil area 102, and a third oil area 103, wherein: Figure 1 The first first oil suction space 3 and the first second oil suction space 3' that are mutually opposed on the left side in Figure 1The second first oil suction space 4 and the second second oil suction space 4' on the right side in it form the second oil area 102, and the space where the motor 2 is located is the third oil area 103. The first oil area 101 and the second oil area 102 are located on the first side of the partition plate 7, and the third oil area 103 is located on the second side of the partition plate 7. The motor output shaft 21 of the motor 2 passes through the partition plate 7 in a non-contact manner and is coaxially connected to the internal gear 11. A second oil passage communicating the second oil area 102 and the third oil area 103 is opened on the partition plate 7, and the oil in the second oil area 102 and the third oil area 103 can flow through the second oil passage. That is to say, the partition plate 7 does not completely isolate the second oil area 102 and the third oil area 103, but leaves a second oil passage to ensure the oil circulation between the second oil area 102 and the third oil area 103 and improve the heat dissipation efficiency of the motor 2.

[0035] In one embodiment, the partition plate 7 is a circular plate, and an arc-shaped gap is opened on the circular plate. The arc-shaped gap forms the second oil passage, and the oil in the second oil area 102 and the third oil area 103 can flow through the arc-shaped gap. Preferably, the width dimension of the arc-shaped gap is 0.1 mm to 1 mm. The selection of this dimension is mainly to ensure the connection between the second oil area 102 and the third oil area 103 while making the pressure change in the third oil area 103 much smaller than the pressure change in the second oil area 102.

[0036] In another embodiment, the partition plate 7 is a circular plate, and a strip-shaped gap extending along its radial direction is opened on the circular plate to form the second oil passage.

[0037] Of course, it can be understood that the shape of the second oil passage is not limited to this. Theoretically, any shape of through hole, notch, etc. can be used as long as it can connect the second oil area 102 and the third oil area 103 on both sides of the partition plate 7.

[0038] Based on the same inventive concept, the embodiment of the present invention also provides a shock absorber, which can be used in other transportation tools such as automobiles and airplanes. The shock absorber includes the aforementioned cycloid pump, hydraulic pipeline and execution unit. The cycloid pump and the execution unit are connected through the hydraulic pipeline, and the cycloid pump realizes the driving action of the execution unit through oil suction and oil discharge actions. Specifically, the execution unit is a hydraulic cylinder. By sucking or discharging oil of the cycloid pump, the oil in each cavity of the hydraulic cylinder is changed, so as to realize the extension and retraction of the piston rod of the hydraulic cylinder.

[0039] In summary, the cycloid pump and the shock absorber of the present invention have the following beneficial effects: A first oil passage communicating the first oil suction space and the second oil suction space is provided on the gear set to achieve double-sided oil suction of the cycloid pump, greatly enhancing the oil suction capacity of the cycloid pump. When the cycloid pump operates at high speed, the oil delivery capacity is improved, enabling the actuator unit of the shock absorber with this cycloid pump to respond quickly. Through double-sided oil suction, the cavitation phenomenon caused by the flowing oil is greatly reduced, and the vibration and noise are decreased. Moreover, the present invention realizes double-sided oil suction only by providing the first oil passage. Compared with the conventional method of realizing double-sided oil suction by increasing the oil circuit, the structure of the cycloid pump and the hydraulic system are greatly simplified.

[0040] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope protected by the claims of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A cycloid pump, comprising a gear set (1), wherein a chamber (10) for oil suction and oil discharge is provided in the gear set (1), and a first oil suction space (3, 4) communicating with the chamber (10) is provided on a first side of the gear set (1), characterized in that, The second side of the gear set (1) opposite to the first side has a second oil suction space (3', 4') communicating with the chamber (10). The second oil suction space (3', 4') is formed by grooving the area of the cycloid pump housing (6) facing the gear set (1) or grooving the gear set (1). The gear set (1) is provided with a first oil passage (5) communicating the first oil suction space (3, 4) and the second oil suction space (3', 4'). The oil in the first oil suction space (3, 4) can be introduced into the second oil suction space (3', 4') through the first oil passage (5). When sucking oil, the gear set (1) can suck oil from the first oil suction space (3, 4) and the second oil suction space (3', 4') into the chamber (10).

2. The cycloidal pump according to claim 1, wherein, The gear set (1) consists of an internal gear (11) and an external gear (12). The external gear (12) is sleeved outside the internal gear (11). The chamber (10) is formed between the internal gear (11) and the external gear (12). At least one of the external gear (12) and / or the internal gear (11) is provided with the first oil passage (5).

3. The cycloid pump according to claim 2, characterized in that, The outer peripheral surface of the internal gear (11) is formed with racks extending outward, and the inner peripheral surface of the external gear (12) is formed with racks extending inward. The first oil passage (5) is provided in part or all of the racks of the external gear (12) and / or the internal gear (11).

4. The cycloid pump according to claim 2, wherein, The first oil passage (5) is a through hole parallel to the central axis of the gear set (1).

5. The cycloidal pump according to claim 1, wherein, The cycloid pump further includes a partition plate (7), a motor (2) for driving the gear set (1) to rotate, and a first oil area (101), a second oil area (102), and a third oil area (103). Among them: The first oil suction space (3) and the first second oil suction space (3') facing each other form the first oil area (101). The second oil suction space (4) and the second second oil suction space (4') facing each other form the second oil area (102). The space where the motor (2) is located is the third oil area (103). The first oil area (101) and the second oil area (102) are located on the first side of the partition plate (7), and the third oil area (103) is located on the second side of the partition plate (7). The partition plate (7) is provided with a second oil passage communicating the second oil area (102) and the third oil area (103).

6. The cycloidal pump according to claim 5, characterized in that, The partition plate (7) is a circular plate, and a strip-shaped gap extending along its radial direction is provided on the circular plate to form the second oil passage.

7. The cycloid pump according to claim 5, characterized in that, The partition plate (7) is a circular plate, and an arc-shaped gap is provided on the circular plate to form the second oil passage.

8. The cycloidal pump according to claim 7, wherein, The width dimension of the arc-shaped gap is 0.1 mm to 1 mm.

9. A shock absorber, comprising a cycloid pump according to any one of claims 1-8, a hydraulic pipeline, and an execution unit. The cycloid pump and the execution unit are communicated through the hydraulic pipeline. The cycloid pump realizes the driving action of the execution unit through the oil suction and oil discharge actions.

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