Cycloid rotor pump for compressor

Abstract

The transmission structure comprises an inner rotor, an outer rotor and a driven shaft, the outer rotor is sleeved outside the inner rotor to form a pump space, the driven shaft penetrates through the inner rotor and the outer rotor, the inner rotor is fixedly connected with the driven shaft, the outer rotor is meshed with the inner rotor, and the outer rotor and the inner rotor are eccentrically arranged. N inner teeth are arranged on the outer rotor, N-1 outer teeth are arranged on the inner rotor, the profile curve of each outer tooth is an inner equidistant line of a curtate epicycloid, the tooth profile curve of each inner tooth is an arc curve, and the inner teeth are in linear contact with the outer teeth. The rotor pump comprises the transmission structure and further comprises a crankshaft, a connecting ring, a shell, a bottom plate, a flange plate, a pump body and an overflow valve. The pump body is connected with one end of the driven shaft, the other end of the driven shaft sequentially penetrates through the inner rotor and the bottom plate to be connected with the crankshaft, the connecting ring sleeves the joint of the driven shaft and the crankshaft, the shell is connected with the bottom plate, the pump body is connected with the bottom plate through a flange plate, and the overflow valve is arranged at the bottom of the pump body.

Description

Technical Field

[0001] The utility model relates to the field of rotor pumps, in particular to a transmission structure of a cycloid rotor pump and a cycloid rotor pump for a compressor. Background Art

[0002] When the lubricating oil volume is less than 40L / min, the compressor circulation lubrication system is mostly driven by the compressor main shaft (crankshaft) to directly drive the oil pump to supply oil to the entire lubrication system.

[0003] The usual oil pump is a gear pump or a rotor pump. Gear pumps are gradually being phased out due to their poor running stability, easy wear, high noise, unstable pressure and other shortcomings, while rotor pumps have good self-priming ability, large delivery flow, simple structure, easy maintenance, low noise and vibration, and are widely used in compressor lubricating oil systems to supply oil and lubricate compressor motion mechanisms.

[0004] However, due to wear and corrosion of lubricating oil, the rotor pump body is prone to leakage. Low-viscosity lubricating oil is particularly prone to leakage and the treatment effect is poor. Utility Model Content

[0005] In order to solve the problems existing in the prior art, the utility model provides a transmission structure of a cycloid rotor pump and a cycloid rotor pump for a compressor.

[0006] The technical solution adopted by the utility model is:

[0007] A transmission structure of a cycloid rotor pump comprises an inner rotor, an outer rotor sleeved outside the inner rotor to form a pump space, and a driven shaft penetrating the inner rotor and the outer rotor, wherein the inner rotor is fixedly connected to the driven shaft, and the outer rotor meshes with the inner rotor.

[0008] The outer rotor is eccentrically arranged with the inner rotor, the outer rotor is provided with N inner teeth, the inner rotor is provided with N-1 outer teeth, the contour curve of the outer teeth is the inner equidistant line of the short-amplitude epicycloid, the tooth profile curve of the inner teeth is a circular arc curve, and the inner teeth are in linear contact with the outer teeth.

[0009] Preferably, the outer tooth profile of the inner rotor and the inner tooth profile of the outer rotor are a pair of conjugate curves.

[0010] Preferably, the meshing clearance between the inner rotor and the outer rotor is 0.03 mm-0.05 mm.

[0011] Preferably, the outer rotor is provided with an inner tooth, and the inner rotor is provided with an outer tooth.

[0012] A cycloid rotor pump for a compressor, comprising the transmission structure of the cycloid rotor pump, and further comprising a crankshaft, a connecting ring, a housing, a base plate, a flange, a pump body and a relief valve;

[0013] The pump body is connected to one end of the driven shaft, and the other end of the driven shaft is successively penetrated by an inner rotor and a bottom plate and connected to the crankshaft, the connecting ring is sleeved at the connection between the driven shaft and the crankshaft, the housing is connected to the bottom plate, the pump body and the bottom plate are connected by a flange, and the overflow valve is arranged at the bottom of the pump body.

[0014] Preferably, the end surface clearance between the outer rotor and the pump body is 0.01mm-0.03mm.

[0015] Preferably, the driven shaft and the crankshaft are connected in a flat square sliding fit.

[0016] Preferably, a sealing ring is provided at the connection between the driven shaft and the crankshaft.

[0017] The beneficial effects of the utility model are as follows: the cycloid rotor pump adopts a design of meshing of an inner rotor and an outer rotor, wherein the contour curve of the inner teeth is the inner equidistant line of a short-amplitude epicycloid, and the tooth profile curve of the outer teeth is a circular arc curve. This design enables line contact between the tooth profiles, which greatly increases the contact area and reduces wear compared to the point contact of traditional gear pumps, thereby improving the operating stability and service life of the pump.

[0018] Due to the line contact design between the tooth profiles of the inner rotor and the outer rotor, the impact and vibration of the pump during operation are reduced, thereby reducing noise and making the operation smoother. By precisely controlling the meshing clearance between the inner rotor and the outer rotor and the clearance between the outer rotor and the end face of the pump body, the sealing performance of the pump can be significantly improved and the leakage of lubricating oil can be reduced. It is particularly suitable for lubricating oil with low viscosity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the inner and outer rotors in the first embodiment of the utility model;

[0020] Figure 2 This is a schematic diagram of the structure of the inner and outer rotors with the rotation center at the marked position in the first embodiment of the utility model;

[0021] Figure 3 This is a schematic diagram of the overall structure of the rotor pump in the second embodiment of the utility model;

[0022] Figure 4 It is a side cross-sectional structural schematic diagram of the second embodiment of the utility model;

[0023] Figure 5 This is a schematic diagram of the bottom plate structure of the second embodiment of the utility model;

[0024] Figure numerals: 1, inner rotor; 101, outer teeth; 2, outer rotor; 201, inner teeth; 3, driven shaft; 4, crankshaft; 5, connecting ring; 6, housing; 7, base plate; 701, shaft hole; 702, oil inlet chamber; 703, oil outlet chamber; 8, flange; 9, pump body; 10, overflow valve; 11, sealing ring; 12, key; 13, bearing. DETAILED DESCRIPTION

[0025] In order to make the purpose, scheme and advantages of the utility model more clearly understood, the utility model is further described in detail below in conjunction with embodiments and drawings. The schematic implementation manner of the utility model and its description are only used to explain the utility model and are not intended to limit the utility model.

[0026] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to those skilled in the art that these specific details are not necessary to implement the present invention. In other embodiments, in order to avoid confusing the present invention, well-known structures, circuits, materials or methods are not specifically described.

[0027] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] In the description of the present invention, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention.

[0029] Embodiment 1

[0030] like Figure 1As shown, a transmission structure of a cycloid rotor pump comprises an inner rotor 1, an outer rotor 2 which is sleeved outside the inner rotor to form a pump space, and a driven shaft 3 which passes through the inner rotor 1 and the outer rotor 2, wherein the inner rotor 1 is fixedly connected to the driven shaft 3, the outer rotor 2 is meshed with the inner rotor 1, the outer rotor 2 is eccentrically arranged with the inner rotor 1, the outer rotor 2 is provided with N inner teeth 201, the inner rotor 1 is provided with N-1 outer teeth 101, the contour curve of the outer teeth 101 is the inner equidistant line of a short-amplitude epicycloid, the tooth profile curve of the inner teeth 201 is a circular arc curve, and the inner teeth 201 are in line contact with the outer teeth 101.

[0031] In this embodiment, if Figure 2 As shown, the rotation center of the inner rotor 1 is O1, the rotation center of the outer rotor 2 is O2, and the eccentricity between the inner rotor 1 and the outer rotor 2 is e.

[0032] The outer rotor 2 is provided with 7 inner teeth, and the inner rotor 1 is provided with 6 outer teeth. The outer tooth profile of the inner rotor 1 and the inner tooth profile of the outer rotor 2 are a pair of conjugate curves. The outer rotor 2 and the inner rotor 1 form 7 working spaces A, B, C, D, E, F, and G. The working volumes of these working spaces change with the rotation of the rotor. When the inner rotor rotates clockwise, on the right side of O1O2, the working volume of the sealed space gradually increases, forming a local vacuum and sucking liquid. This is the oil suction process of the cycloid rotor pump, while on the left side of O1O2, the working volume of the sealed space gradually decreases, and the liquid is discharged. This is the oil discharge process of the cycloid rotor pump. Since the inner rotor rotates one circle, the outer rotor only rotates 6 / 7 circles. Therefore, when the inner rotor rotates one circle, the working volume of each sealed space formed by the tooth profiles of the inner rotor and the outer rotor only completes 6 / 7 of the oil suction and oil discharge process. If it continues to rotate, it will continue to work.

[0033] Furthermore, the meshing clearance between the inner rotor 1 and the outer rotor 2 is 0.03mm-0.05mm. The inner and outer rotors are made of nano-wear-resistant powder metallurgy materials that are pressed and formed in one step, which ensures the matching accuracy of the inner and outer rotors.

[0034] In this embodiment, the outer tooth profile of the inner rotor is the inner equidistant line of the short-amplitude epicycloid, while the inner tooth profile of the outer rotor is a circular arc curve. This design allows the inner and outer rotors to form a line contact when meshing, improving the stability of the transmission and the sealing performance. The meshing clearance between the inner and outer rotors is controlled between 0.03mm and 0.05mm, which not only ensures a good seal between the two, but also avoids the jamming caused by too tight meshing. The appropriate meshing clearance ensures good sealing performance and avoids the occurrence of oil leakage. Through the eccentric setting and tooth number configuration of the inner and outer rotors, a continuous oil suction and discharge process is achieved, meeting the working requirements of the pump.

[0035] Embodiment 2:

[0036] A cycloid rotor pump for a compressor, such as Figure 3 and Figure 4 As shown, the transmission structure of the cycloid rotor pump described in Example 1 also includes a crankshaft 4, a connecting ring 5, a housing 6, a base plate 7, a flange 8, a pump body 9 and a relief valve 10.

[0037] The pump body 9 is connected to one end of the driven shaft 3, the other end of the driven shaft 3 is successively penetrated by the inner rotor 1 and the bottom plate 7 and connected to the crankshaft 4, and the connecting ring 5 is sleeved at the connection between the driven shaft 3 and the crankshaft 4. For reference, Figure 4 As shown, the pump body 9 and the driven shaft 3 can indeed be connected through the bearing 13, and the bearing can relatively isolate the rotational motion of the driven shaft 3 from the pump body 9, reducing the friction and wear between the two, thereby improving the overall performance and life of the pump. At the same time, the bearing can also withstand the radial and axial loads generated by the driven shaft during the rotation process, maintaining the stable operation of the driven shaft.

[0038] like Figure 3 As shown, the inner rotor 1 and the driven shaft 3 can be connected by a key 12. Key connection is a commonly used connection method in mechanical transmission, which can achieve fixation and torque transmission between two components. The key connection between the inner rotor and the driven shaft can ensure that the connection between them is firm and reliable, thereby ensuring the normal operation of the compressor.

[0039] For reference, there is a main oil hole in the crankshaft 4, and the driven shaft 3 extends into the main oil hole of the crankshaft 4 through the connecting ring 5. The crankshaft 4 and the driven shaft 3 are sealed by an O-ring to prevent oil leakage at the joint between the two.

[0040] The housing 6 is connected to the base plate 7 , and the housing provides necessary structural support for the internal components of the pump, while also protecting these components from external impact and damage.

[0041] The pump body 9 is connected to the base plate 7 via a flange 8. Figure 5 As shown, Figure 2 As shown, the bottom plate 7 is provided with an axial hole 701, an oil inlet chamber 702 and an oil outlet chamber 703, the axial hole 701 is adapted to the driven shaft 3, the oil inlet chamber 702 is connected to the oil suction working area, and the oil outlet chamber 703 is connected to the oil discharge working area.

[0042] The oil inlet cavity 702 and the oil outlet cavity 703 are symmetrically arranged along the axis of the shaft hole 701, and the oil inlet cavity 702 and the oil outlet cavity 703 are arc-shaped cavities. The shaft hole 701 is an eccentric circular hole.

[0043] The oil inlet chamber 702 and the oil outlet chamber 703 both include an arc-shaped outer wall and an arc-shaped inner wall. The contour line of the arc-shaped outer wall coincides with the moving trajectory of the inner tooth top, the curvature of the arc-shaped inner wall contour line is the same as the curvature of the arc-shaped outer wall contour line, and the moving trajectory of the outer tooth top is located between the arc-shaped outer wall contour line and the arc-shaped inner wall contour line.

[0044] During the operation of the cycloidal rotor pump for the entire compressor, the arc-shaped outer wall of the oil inlet cavity coincides with the moving trajectory of the outer tooth tops of the inner rotor, thereby achieving smooth flow of lubricating oil in the pump body. When the inner rotor rotates inside the outer rotor, its outer tooth tops move along this contour line. When the oil suction working area gradually increases with the rotation of the inner rotor, the oil inlet cavity can quickly connect with the oil suction working area, allowing the external lubricating oil to be smoothly sucked in.

[0045] The curvature of the contour line of the arc-shaped inner wall of the oil inlet cavity is the same as that of the arc-shaped outer wall, forming a smooth transition area, which further ensures the smooth flow of the lubricating oil and reduces the eddy currents and turbulences that may be generated during the flow of the lubricating oil, thereby reducing energy loss and improving the efficiency of the pump.

[0046] The oil inlet cavity also helps reduce the wear of the rotor by foreign particles. Since the lubricating oil needs to pass through the oil inlet cavity before entering the oil suction working area, the arc-shaped outer and inner walls of the oil inlet cavity can effectively guide and filter the lubricating oil, so that the foreign particles in it are effectively separated before contacting the rotor. In this way, the rotor can avoid direct contact with these particles during rotation, thereby greatly reducing the possibility of wear.

[0047] The oil outlet cavity is similar to the oil inlet cavity. It is also located on the bottom plate and connected to the oil discharge working area. The contours of its arc-shaped outer and inner walls are also designed according to the movement trajectory of the tooth tops of the inner rotor's outer teeth. When the inner rotor brings the lubricating oil from the oil suction working area to the oil discharge working area, the high-pressure lubricating oil will flow along the arc-shaped outer and inner walls of the oil outlet cavity and finally be discharged from the pump body through the oil outlet.

[0048] This design of the oil outlet chamber not only ensures that the lubricating oil can be discharged smoothly, but also further reduces the impact of foreign particles on the rotor. Since the arc-shaped outer and inner walls of the oil outlet chamber can effectively guide the lubricating oil, the foreign particles in it are effectively separated. In this way, the rotor will not be disturbed by these particles during the rotation process, thus ensuring the stable operation of the pump.

[0049] The relief valve 10 is arranged at the bottom of the pump body 9. For reference, according to the interface size and type of the relief valve 10, a corresponding mounting hole or interface is processed or reserved at the bottom of the pump body 9. Ensure that the connection between the relief valve and the pump body is tight and reliable to prevent liquid leakage.

[0050] In this embodiment, the crankshaft is connected to the driven shaft through a connecting ring. When the crankshaft rotates under the drive of the compressor, the power is transmitted to the inner rotor through the driven shaft. When the inner rotor rotates clockwise, on the right side of O1O2, the working volume of the sealed space gradually increases, forming a local vacuum and sucking in liquid. This is the oil suction process of the cycloid rotor pump. On the left side of O1O2, the working volume of the sealed space gradually decreases, and the liquid is discharged. This is the oil discharge process of the cycloid rotor pump. The sucked liquid enters the compressor system through the pump body to complete the corresponding process. When the pressure in the pump body exceeds the set value, the overflow valve will automatically open to release excess pressure and protect the pump and the system from damage.

[0051] If the end surface clearance between the outer rotor 2 and the pump body 9 is too small, friction may increase, wear may increase, and even cause jamming; if the clearance is too large, sealing performance may decrease, and liquid may easily leak from the end surface. In this embodiment, the end surface clearance between the outer rotor 2 and the pump body 9 is 0.01mm-0.03mm. Within this clearance range, the contact between the rotor and the pump body is close, which can effectively prevent liquid from leaking from the end surface, thereby ensuring sealing performance and reducing wear.

[0052] In this embodiment, the driven shaft 3 and the crankshaft 4 are connected in a flat square sliding fit. This connection method not only ensures the effective transmission of power, but also allows a certain amount of sliding to accommodate slight deformation during operation.

[0053] In this embodiment, a sealing ring is provided at the connection between the driven shaft 3 and the crankshaft 4 to further ensure the sealing performance of the connection and prevent liquid leakage.

[0054] The above-mentioned embodiments only express the specific implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the utility model. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model.

Claims

1. A cycloidal rotor pump for a compressor, comprising an inner rotor (1), an outer rotor (2) sleeved outside the inner rotor to form a pump space, and a driven shaft (3) passing through the inner rotor (1) and the outer rotor (2), wherein the inner rotor (1) is fixedly connected to the driven shaft (3), and the outer rotor (2) is meshed with the inner rotor (1), characterized in that: The outer rotor (2) and the inner rotor (1) are eccentrically arranged, the outer rotor (2) is provided with N internal teeth (201), the inner rotor (1) is provided with N-1 external teeth (101), the contour curve of the external teeth (101) is an inner equidistant line of a short-amplitude epicycloid, the tooth profile curve of the internal teeth (201) is an arc curve, the internal teeth (201) are in line contact with the external teeth (101), and further comprises a crankshaft (4), a connecting ring (5), a housing (6), a base plate (7), a flange (8), a pump body (9) and a relief valve (10); The pump body (9) is connected to one end of the driven shaft (3); the other end of the driven shaft (3) is successively penetrated by an inner rotor (1) and a bottom plate (7) and connected to the crankshaft (4); the connecting ring (5) is sleeved at the connection between the driven shaft (3) and the crankshaft (4); the housing (6) is connected to the bottom plate (7); the pump body (9) and the bottom plate (7) are connected via a flange (8); and the overflow valve (10) is arranged at the bottom of the pump body (9).

2. A cycloid rotor pump for a compressor according to claim 1, characterized in that: The end surface clearance between the outer rotor (2) and the pump body (9) is 0.01 mm to 0.03 mm.

3. A cycloid rotor pump for a compressor according to claim 1, characterized in that: The driven shaft (3) and the crankshaft (4) are connected in a flat square sliding fit.

4. A cycloid rotor pump for a compressor according to claim 1, characterized in that: A sealing ring (11) is provided at the connection between the driven shaft (3) and the crankshaft (4).

5. The cycloid rotor pump for a compressor according to claim 1, characterized in that: The outer tooth profile of the inner rotor (1) and the inner tooth profile of the outer rotor (2) are a pair of conjugate curves.

6. A cycloid rotor pump for a compressor according to claim 1, characterized in that: The meshing clearance between the inner rotor (1) and the outer rotor (2) is 0.03 mm to 0.05 mm.

7. A cycloid rotor pump for a compressor according to claim 1, characterized in that: The outer rotor (2) is provided with 7 internal teeth, and the inner rotor (1) is provided with 6 external teeth.

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