Integrated type lubricating device for a gerotor pump

Abstract

The utility model discloses an integrated type swing cycle pump lubricating device, including pump casing, inner rotor and outer rotor, be provided with oil cavity and with oil inlet and oil outlet of oil cavity communication on the pump casing, its characterized in that, the bottom of oil cavity is provided with annular unloading groove with oil outlet communication, and the bottom surface of annular unloading groove is multistage step surface. This integrated type swing cycle pump lubricating device can effectively buffer fluid resistance and pulsation, reduce cavitation and cavitation erosion phenomenon, and stabilize oil pressure of oil outlet.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic power component technology, specifically to an integrated cycloidal pump lubrication device. Background Technology

[0002] In recent years, the domestic automobile market has entered a period of rapid development. Automobiles integrate various oil pumps, such as engine oil pumps, steering pumps, fuel pumps, and hydraulic automatic transmission oil pumps. Among them, transmission oil pumps have high working pressure and large displacement, and have the highest performance requirements for vehicle oil pumps. As a highly integrated component, hydraulic automatic transmissions have built-in cycloidal pumps, which are currently the gear pumps with the highest displacement / volume ratio, and are therefore widely used in hydraulic automatic transmissions.

[0003] Currently, domestically produced cycloidal pumps have the following defects:

[0004] 1. Poor temperature adaptability: At high temperatures, material expansion leads to increased rotor clearance and a sharp drop in volumetric efficiency; at low temperatures, oil viscosity increases, oil suction resistance increases, and noise increases significantly.

[0005] 2. Flow restriction: In order to maintain sealing, conventional design requires sacrificing displacement, and unreasonable oil passage design can easily cause cavitation under high flow.

[0006] 3. Structural redundancy: Relies on additional seals to compensate for thermal deformation, increasing the risk of leakage and assembly complexity. Utility Model Content

[0007] To address the shortcomings of existing technologies, the technical problem to be solved by this utility model is to provide an integrated cycloidal pump lubrication device that can effectively buffer fluid resistance and pulsation, reduce cavitation and cavitation phenomena, and stabilize the oil pressure at the oil outlet.

[0008] To achieve the above objectives, this utility model provides the following technical solution: an integrated cycloidal pump lubrication device, comprising:

[0009] The pump includes a pump housing, an inner rotor, and an outer rotor. The pump housing is provided with an oil cavity and an oil inlet and an oil outlet communicating with the oil cavity. The pump is characterized in that an annular unloading groove communicating with the oil outlet is provided at the bottom of the oil cavity, and the bottom surface of the annular unloading groove is a multi-level stepped surface.

[0010] Furthermore, the tooth profile of the inner rotor is an equidistant curve of a short-amplitude epicycloid generated based on the parametric equation of the short-amplitude epicycloid; the tooth profile of the outer rotor is a conjugate equidistant curve.

[0011] Furthermore, the short amplitude coefficient K1 of the tooth profile of the inner rotor satisfies: 0.62≤K1≤0.68.

[0012] Furthermore, the ratio of the root circle radius Re to the eccentricity e of the tooth profile of the outer rotor satisfies: Re / e = 4.8 ± 0.2.

[0013] Furthermore, both the oil inlet and the oil outlet adopt an asymmetric conical diffusion channel with an inlet cone angle β = 18° ± 2°.

[0014] Furthermore, the volume V of the oil outlet and the single-rotation displacement V0 satisfy the following condition: V = 1.8V0 - 2.2V0.

[0015] Furthermore, the two axial end faces of the inner rotor are micro-convex spherical surfaces.

[0016] The beneficial effects of this utility model are:

[0017] The aforementioned integrated cycloidal pump lubrication device includes a pump housing, an inner rotor, and an outer rotor. The pump housing is provided with an oil chamber and an oil inlet and an oil outlet communicating with the oil chamber. The bottom of the oil chamber is provided with an annular unloading groove communicating with the oil outlet, and the bottom surface of the annular unloading groove is a multi-level stepped surface.

[0018] This integrated cycloidal pump lubrication device uses an annular unloading groove. The height difference of its multi-stage stepped surface forms a vortex zone, which can buffer fluid resistance and pulsation, reduce cavitation and cavitation phenomena, stabilize outlet oil pressure, smooth the oil pressure gradient, and significantly reduce the pulsation amplitude. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of this utility model, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0020] Figure 1 A schematic diagram of an integrated cycloidal pump lubrication device provided in an embodiment of this utility model;

[0021] Figure 2 for Figure 1 A schematic diagram of the pump housing in the integrated cycloidal pump lubrication device shown;

[0022] Figure 3 for Figure 1 A schematic diagram of the micro-convex spherical surface in the integrated cycloidal pump lubrication device shown;

[0023] Figure label:

[0024] 100, Pump housing; 110, Oil chamber; 120, Oil inlet; 130, Oil outlet; 200, Inner rotor; 210, Micro-convex spherical surface; 300, Outer rotor. Detailed Implementation

[0025] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention; therefore, the invention is not limited to the specific embodiments disclosed below.

[0026] Please see Figures 1 to 3 This utility model provides an integrated cycloidal pump lubrication device, including a pump housing 100, an inner rotor 200 and an outer rotor 300. The pump housing 100 is provided with an oil chamber 110 and an oil inlet 120 and an oil outlet 130 communicating with the oil chamber 110. The bottom of the oil chamber 110 is provided with an annular unloading groove communicating with the oil outlet 130, and the bottom surface of the annular unloading groove is a multi-level stepped surface.

[0027] This integrated cycloidal pump lubrication device uses an annular unloading groove. The height difference of its multi-stage stepped surface forms a vortex zone, which can buffer fluid resistance and pulsation, reduce cavitation and cavitation phenomena, stabilize outlet oil pressure, smooth the oil pressure gradient, and significantly reduce the pulsation amplitude.

[0028] In this example, the tooth profile of the inner rotor 200 is an equidistant curve of a short-amplitude epicycloid generated based on the parametric equation of the short-amplitude epicycloid. The equidistant curve of the short-amplitude epicycloid has the characteristics of no singularities and smooth transitions, which can effectively improve the smoothness and wear resistance of the transmission. The parametric equation of the short-amplitude epicycloid is as follows:

[0029]

[0030] Where a and b represent the amplitude and angular frequency of the cycloid, respectively, and t represents time or angle. The curve described by this parametric equation is periodic, and within each period, it is tangent to the tangent line at every point on the curve.

[0031] In practical implementation, the short amplitude coefficient K1 of the tooth profile of the inner rotor 200 satisfies: 0.62≤K1≤0.68.

[0032] Finite element thermodynamic simulation revealed that when K1 < 0.62, the tooth tip clearance is too small at high temperatures, leading to wear; when K1 > 0.68, the tooth root is prone to interference at low temperatures. The optimal K1 = 0.65 ensures that the clearance remains consistently between 0.01 mm and 0.02 mm under operating conditions of -40℃ to 150℃.

[0033] In this example, the tooth profile of the outer rotor 300 is a conjugate equidistant curve. In specific implementation, the ratio of the root circle radius Re to the eccentricity e of the tooth profile of the outer rotor 300 satisfies: Re / e = 4.8 ± 0.2.

[0034] By employing this type of inner rotor 200 and outer rotor 300, a wide-temperature-range toothed compensation structure can be formed. This parameter combination maintains a critical sealing gap of ≤0.02mm during high-temperature expansion and avoids interference during low-temperature contraction. This improves the stability of pressure, flow, and other performance characteristics of the wide-temperature-range integrated cycloidal pump in high-power hydraulic automatic transmissions.

[0035] In a preferred embodiment, both the oil inlet 120 and the oil outlet 130 of this device adopt an asymmetric conical diffuser channel with an inlet cone angle β = 18° ± 2°. The volume V of the oil outlet 130 satisfies the single-rotation displacement V0: V = 1.8V0 - 2.2V0. This method can effectively suppress high-pressure pulsation and reduce the risk of cavitation.

[0036] As another preferred embodiment, in a further preferred embodiment, the axial end faces of the inner rotor 200 can be micro-convex spherical surfaces 210. In a specific embodiment, the radius of curvature R of the micro-convex spherical surfaces 210 can be 300mm-500mm. This can reduce abnormal wear caused by linear contact at the tooth tips due to attitude changes during the tilting and rotation of the inner rotor 200, and reduce end face leakage.

[0037] Furthermore, it should be noted that during processing, the pump housing 100 can be treated with a combination of laser texturing and solid lubricant spraying to control the density, arrangement, and coating thickness of surface micropores. For the inner rotor 200 and outer rotor 300, steam oxidation control technology is applied, using parameters such as differences in material thermal conductivity, the degree of oxidation reaction of alloying elements, holding time, and dynamic steam pressure to optimize deformation control. This reduces quality problems in parts during steam oxidation, enhances the self-lubricating properties of the part surface, reduces the coefficient of friction, and ensures part precision.

[0038] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. An integrated cycloidal pump lubrication device, comprising a pump housing, an inner rotor, and an outer rotor, wherein the pump housing is provided with an oil chamber and an oil inlet and an oil outlet communicating with the oil chamber, characterized in that, The bottom of the oil cavity is provided with an annular unloading groove that communicates with the oil outlet, and the bottom surface of the annular unloading groove is a multi-level stepped surface.

2. The integrated cycloidal pump lubrication device according to claim 1, characterized in that, The tooth profile of the inner rotor is an equidistant curve of a short-amplitude epicycloid generated based on the parametric equation of the short-amplitude epicycloid; the tooth profile of the outer rotor is a conjugate equidistant curve.

3. The integrated cycloidal pump lubrication device according to claim 2, characterized in that, The short amplitude coefficient K1 of the tooth profile of the inner rotor satisfies: 0.62≤K1≤0.

68.

4. The integrated cycloidal pump lubrication device according to claim 2, characterized in that, The ratio of the root circle radius Re to the eccentricity e of the tooth profile of the outer rotor satisfies: Re / e = 4.8 ± 0.

2.

5. The integrated cycloidal pump lubrication device according to claim 1, characterized in that, Both the oil inlet and the oil outlet adopt an asymmetric conical diffusion channel with an inlet cone angle β = 18° ± 2°.

6. The integrated cycloidal pump lubrication device according to claim 1, characterized in that, The volume V of the oil outlet and the single-rotation displacement V0 satisfy the following condition: V = 1.8V0 - 2.2V0.

7. The integrated cycloidal pump lubrication device according to claim 1, characterized in that, The two axial end faces of the inner rotor are slightly convex spherical surfaces.

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