A design method of a multi-eccentricity eccentric interstage casing lubricating oil pump

Abstract

The present application belongs to the technical field of structural design and lubricating system design, and relates to a lubricating oil pump structure, in particular to a design method of a lubricating oil pump with a multi-eccentricity eccentric inter-stage shell. The spatial positions of inner and outer rotors are repositioned by offsetting the rotation center of the inner rotor, and the eccentric sleeve is designed along the eccentricity direction based on the value of the large eccentricity. The inter-stage shell structure is designed according to the positions of the inner and outer rotors, i.e. the inter-stage shell is an eccentric inter-stage shell. Compared with the traditional concentric inter-stage shell structure, the radial dimensions of the eccentric sleeve and the inter-stage shell are greatly reduced. The great reduction in size directly reduces the weight of the eccentric sleeve and the inter-stage shell, thereby reducing the overall weight of the lubricating oil pump. In addition, the radial space of the lubricating oil pump is directly reduced, thereby reducing the overall size of the lubricating oil pump.

Description

Technical Field

[0001] This invention belongs to the technical field of structural design and lubrication system design, and relates to the structure of lubricating oil pumps, specifically a design method for an eccentric interstage housing lubricating oil pump with multiple eccentricities. Background Technology

[0002] The lubricating oil pump is a core component of the lubrication system. Its function is to continuously circulate lubricating oil within the system, lubricating and cooling components such as gears and bearings in the mechanical transmission system. Through continuous operation, the lubricating oil pump can also return the lubricated and cooled oil to the oil tank. Aviation lubricating oil pumps often adopt a cycloidal gear pump structure. The cycloidal pump drives the rotation of each pair of internally meshing cycloidal gear rotors through the pump shaft, inputting lubricating oil from the pump inlet to the outlet, thus lubricating and cooling the downstream accessory units. The core design of the cycloidal pump to achieve oil suction is the interstage housing design. The profile of the interstage housing covers the maximum cavity formed by the inner and outer rotors. The cavity of the interstage housing ensures the sealing of the lubricating oil during rotation, thereby creating a pressure differential to achieve oil supply.

[0003] Oil pumps generally have both suction and return functions, meaning they integrate a booster stage and a return stage. Depending on the operating conditions, the flow rate, inlet pressure, outlet pressure, and other boundary conditions of the booster and return stages differ. To meet different design input requirements, the booster and return stages of the oil pump need to use rotor structures with different eccentricities. The outer diameter of the outer rotor and the outer diameter of the eccentric sleeve correspond to different eccentricity rotor structures. The power input of the oil pump is driven by the pump shaft, and the transmission design is centered on the pump shaft. The pump shaft connects to the inner rotor, and the eccentric sleeve is designed according to the eccentricity. Finally, the interstage housing is designed based on the structural forms of the inner rotor, outer rotor, and eccentric sleeve.

[0004] Taking the design of lubricating oil pumps with 3.5mm and 4.9mm eccentricity as examples, the above-mentioned lubricating oil pump structure design has certain design drawbacks. Therefore, when there are two different eccentricities, the lubricating oil pump needs to use the size of the component with the larger eccentricity as a reference. The outer diameter of the eccentric sleeve and interstage housing corresponding to the smaller eccentricity increases accordingly, which in turn increases the weight of the lubricating oil pump components. Summary of the Invention

[0005] Purpose of the invention

[0006] A novel interstage housing structure for a lubricating oil pump is provided. Without affecting the volumetric efficiency and operational reliability of the lubricating oil pump, the eccentric interstage housing structure reduces the outer diameter of the eccentric sleeve and the interstage housing, thereby significantly reducing the weight and radial dimensions of the lubricating oil pump.

[0007] Technical solution

[0008] A design method for a multi-eccentricity eccentric interstage housing lubricating pump structure includes the following steps:

[0009] Step 1: Determine the rotor structure of the lubricating oil pump based on the input parameters and design the eccentricity dimension;

[0010] Step 2: Determine the dimensions of the lubricating oil pump housing and the internal flow channel layout based on the interface dimensions, and design the pump housing structure;

[0011] Step 3: Determine the dimensions of the power input structure based on the host power input parameters, and design the pump shaft structure;

[0012] Step 4: Based on the position of the inlet and outlet flow channels and the rotor structure of the lubricating oil pump, determine the input center of the pump shaft. For lubricating oil pumps with multiple eccentricities, take the size of the largest eccentricity as the reference and offset it along the position of the largest cavity to determine the center of the outer rotor with the largest eccentricity. Under the premise of ensuring the strength of the eccentric sleeve structure, design the eccentric sleeve with the largest eccentricity.

[0013] Step 5: Based on the principle that all inner rotors are concentric, the center of the outer rotor can be determined according to the small eccentricity size. The outer diameter of the small eccentricity eccentric sleeve is the same as that of the large eccentricity eccentric sleeve. The small eccentricity eccentric sleeve structure is designed.

[0014] Step 6: Determine the inner and outer diameter centers of the interstage housing based on the positions of the rotor and the eccentric sleeve. The inner diameter of the interstage housing is concentric with the inner rotor, and the outer diameter of the interstage housing is concentric with the outer diameter of the eccentric sleeve. Then, design the profile of the interstage housing according to the principle of covering the largest cavity, and design the eccentric interstage housing structure.

[0015] Step 7: Determine the sealing requirements based on the structural location of the components and design the sealing structure of the lubricating oil pump;

[0016] Step 8: Determine the error prevention scheme based on the position of the interstage housing and eccentric sleeve, and design the error prevention structure of the lubricating oil pump;

[0017] Step 9: Determine the axial deformation of the oil pump based on the material expansion coefficients and boundary conditions of the oil pump housing, eccentric sleeve, and interstage housing, and design the disc structure of the oil pump.

[0018] Step 10: Determine the bearing position based on the load-bearing position of the rotating component and design the lubrication channel structure;

[0019] Furthermore, step 11 involves assembling the lubricating oil pump after adopting the structural design from steps 1 to 10, conducting simulation analysis, and verifying the accuracy of the structural design.

[0020] Furthermore, a multi-eccentricity eccentric interstage housing lubricating pump structure includes a type I inner rotor 1, a type I outer rotor 2, a small-eccentricity concentric eccentric sleeve 3, a small-eccentricity concentric interstage housing 4, a type II inner rotor 5, a type II outer rotor 6, a large-eccentricity concentric eccentric sleeve 7, a large-eccentricity concentric interstage housing 8, a small-eccentricity eccentric sleeve 9, a small-eccentricity eccentric interstage housing 10, a large-eccentricity eccentric sleeve 11, and a large-eccentricity eccentric interstage housing 12.

[0021] Furthermore, the Type I inner rotor 1 and Type I outer rotor 2 are respectively installed in the small eccentricity concentric sleeve 3 and the small eccentricity eccentric sleeve 9; the Type II inner rotor 5 and Type II outer rotor 6 are respectively installed in the large eccentricity concentric sleeve 7 and the large eccentricity eccentric sleeve 11; the small eccentricity concentric interstage housing 4 is used in conjunction with the Type I inner rotor 1, the Type I outer rotor 2, and the small eccentricity concentric sleeve 3; the large eccentricity concentric interstage housing 8 is used in conjunction with the Type II inner rotor, the Type II outer rotor 6, and the large eccentricity concentric sleeve 7; the small eccentricity eccentric interstage housing 10 is used in conjunction with the Type I inner rotor 1, the Type I outer rotor 2, and the small eccentricity eccentric sleeve 9; and the large eccentricity eccentric interstage housing 12 is used in conjunction with the Type II inner rotor 5, the Type II outer rotor 6, and the large eccentricity eccentric sleeve 11.

[0022] Furthermore, the small eccentricity is 3.5 mm.

[0023] Furthermore, the large eccentricity is 4.9 mm.

[0024] Furthermore, by offsetting the rotation center of the inner rotor, the spatial positions of the inner and outer rotors are repositioned, and an eccentric sleeve is designed along the eccentricity direction based on the value of the large eccentricity.

[0025] Furthermore, the interstage shell structure is designed according to the positions of the inner and outer rotors, that is, the interstage shell is an eccentric interstage shell.

[0026] The beneficial effects of this application are as follows:

[0027] The eccentric interstage housing structure replaces the traditional concentric interstage housing structure, significantly reducing the radial dimensions of the eccentric sleeve and interstage housing. This substantial reduction in size directly reduces the weight of the eccentric sleeve and interstage housing, thereby lowering the overall weight of the oil pump. Secondly, it directly reduces the radial space of the oil pump, thus shrinking its overall dimensions. Weight and dimensional specifications are particularly important for aerospace products. For the oil pump itself, reduced weight and dimensions optimize product structure, increase design freedom, and enhance core competitiveness. For the entire aircraft, reduced oil pump weight and dimensions reduce overall fuel consumption and improve performance. Attached Figure Description

[0028] Figure 1 The part drawing for the 3.5mm eccentricity concentric scheme in the background technology;

[0029] Figure 2 The part drawing for the 4.9mm eccentricity concentric scheme in the background technology;

[0030] Figure 3 This is a part drawing of the 3.5mm eccentricity scheme of the present invention;

[0031] Figure 4 This is a part drawing of the 4.9mm eccentricity scheme of the present invention;

[0032] Figure 5 This is a schematic diagram of the 3.5mm eccentricity interstage shell of the present invention;

[0033] Figure 6 This is a schematic diagram of the 4.9mm eccentricity interstage housing of the present invention;

[0034] Figure 7 This is a schematic diagram of the 3.5mm eccentricity sleeve of the present invention;

[0035] Figure 8 This is a schematic diagram of the 4.9mm eccentricity sleeve of the present invention.

[0036] Wherein: 1—Type I inner rotor, 2—Type I outer rotor, 3—Small eccentricity concentric sleeve, 4—Small eccentricity concentric interstage shell, 5—Type II inner rotor, 6—Type II outer rotor, 7—Large eccentricity concentric sleeve, 8—Large eccentricity concentric interstage shell, 9—Small eccentricity eccentric sleeve, 10—Small eccentricity eccentric interstage shell, 11—Large eccentricity eccentric sleeve, 12—Large eccentricity eccentric interstage shell, 13—3.5mm eccentricity Concentric interstage shell models with a center distance of 14-3.5mm, eccentric interstage shell models with an eccentric distance of 15-4.9mm, eccentric interstage shell models with an eccentric distance of 16-4.9mm, concentric eccentric sleeve models with an eccentric distance of 17-4.9mm, eccentric eccentric sleeve models with an eccentric distance of 18-4.9mm, concentric eccentric sleeve models with an eccentric distance of 19-3.5mm, and eccentric eccentric sleeve models with an eccentric distance of 20-3.5mm. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be described in more detail below. In the examples, the same or similar reference numerals denote the same or similar components or elements having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of this invention. The embodiments described below with reference to reference are exemplary and intended to explain this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The embodiments of this invention will be described in detail below.

[0038] This solution uses 3.5mm and 4.9mm eccentricity lubricating pump designs as examples to introduce the traditional concentric lubricating pump interstage housing design. A schematic diagram of the 3.5mm eccentricity structure can be found here. Figure 1 The type I inner rotor 1 is centered at the pump shaft input center, i.e., the origin coordinates are (0, 0, 0). The type I outer rotor 2 is offset along the eccentricity, with coordinates (0, 3.5, 0). The outer diameter center coordinates of the concentric eccentric sleeve 3 with small eccentricity are (0, 0, 0), and the inner diameter center coordinates are (0, 3.5, 0). The coordinates of the concentric interstage shell 4 with small eccentricity are (0, 0, 0). A schematic diagram of the 4.9mm eccentricity structure is shown below. Figure 2 The type II inner rotor 5 is centered at the pump shaft input center, i.e., the origin coordinates are (0, 0, 0). The type II outer rotor 6 is offset along the eccentricity, with coordinates (0, 4.9, 0). The outer diameter center coordinates of the large eccentricity concentric sleeve 7 are (0, 0, 0), and the inner diameter center coordinates are (0, 4.9, 0). The coordinates of the large eccentricity concentric interstage housing 8 are (0, 0, 0). Based on the 3.5mm eccentricity structural design, and ensuring the structural strength of the eccentric sleeve, the outer diameter of the interstage housing is 79.2mm. Based on the 4.9mm eccentricity structural design, and ensuring the structural strength of the eccentric sleeve, the outer diameter of the interstage housing is 84.8mm. Since both types of interstage housings are assembled in the pump housing, their outer diameters must be consistent. Therefore, the outer diameter of the interstage housing with a 3.5mm eccentricity must also be 84.8mm.

[0039] 1. Core Invention Point: A novel interstage housing structure for a lubricating oil pump. By offsetting the rotation center of the inner rotor, the spatial positions of the inner and outer rotors are repositioned. Using a large eccentricity as a reference, an eccentric sleeve is designed along the eccentricity direction. The interstage housing structure is then designed according to the positions of the inner and outer rotors, resulting in an eccentric interstage housing. Compared to the traditional concentric interstage housing structure, this eccentric interstage housing structure reduces the outer diameter of both the interstage housing and the eccentric sleeve by a factor of two, thereby significantly reducing the weight of both the interstage housing and the eccentric sleeve.

[0040] Secondary invention points: The outer diameter of the interstage housing and eccentric sleeve of the eccentric interstage housing structure is reduced, and the inner diameter of the oil pump housing that matches it is also reduced, resulting in a significant reduction in the overall size of the oil pump.

[0041] Three key invention points: The inner diameter of the lubricating pump housing with the eccentric interstage housing structure is reduced, which directly leads to a reduction in the weight of the lubricating pump housing. The reduction in the weight of the pump housing will directly reduce the weight of the lubricating pump.

[0042] Four key inventions: The eccentric interstage housing structure optimizes the design of the lubricating pump, solves the design drawbacks of multi-eccentric lubricating pumps, and enriches the application scenarios of multi-eccentric lubricating pumps.

[0043] Five key inventions: The eccentric interstage housing structure of the lubricating pump reduces the weight of the eccentric sleeve, interstage housing, and pump housing, optimizing the weight distribution of lubricating pump components.

[0044] Six key inventions: The eccentric interstage housing structure reduces the weight of the lubricating pump, which can improve the structural strength of the pump housing mounting edge and enhance the operational reliability of the lubricating pump.

[0045] Seven key inventions: The eccentric interstage housing structure reduces the weight of the lubricating pump, increases the design space for the thickness of the inner and outer rotors, and helps to improve the flow performance of the lubricating pump.

[0046] 8 Secondary Invention Points: The eccentric interstage housing structure profile design has no effect on the radial dimensions of the lubricating pump.

[0047] Nine key invention points: The design of the eccentric interstage housing profile is consistent with the design method of the concentric interstage housing profile, and has no impact on the volumetric efficiency of the lubricating pump.

[0048] A multi-eccentricity eccentric interstage housing lubricating pump structure, compared with the concentric interstage housing scheme, taking the lubricating pump designs with 3.5mm eccentricity and 4.9mm eccentricity as examples, includes a type I inner rotor 1, a type I outer rotor 2, a small eccentricity eccentric sleeve 9, and a small eccentricity eccentric interstage housing 10 with a 3.5mm eccentricity. The type I inner rotor 1 and type I outer rotor 2 are assembled in the small eccentricity eccentric sleeve 9 and used in conjunction with the small eccentricity eccentric interstage housing 10. The 4.9mm eccentricity structure includes a type II inner rotor 5, a type II outer rotor 6, a large eccentricity eccentric sleeve 11, and a large eccentricity eccentric interstage housing 12 with a 4.9mm eccentricity. The type II inner rotor 5 and type II outer rotor 6 are assembled in the large eccentricity eccentric sleeve 11 and used in conjunction with the large eccentricity eccentric interstage housing 12.

[0049] See the schematic diagram of the 3.5mm eccentricity structure. Figure 3 The center of the Type I inner rotor 1 is the pump shaft input center, i.e., the origin coordinates (0, 0, 0). The center of the Type I outer rotor 2 is offset along the eccentricity, with coordinates (0, 0, 0).

[0050] The outer diameter center coordinates of the concentric eccentric sleeve 3 with small eccentricity are (0, 3.5, 0), and the inner diameter center coordinates are (0, 3.5, 0). The coordinates of the concentric interstage shell 4 with small eccentricity are (0, 4.9, 0).

[0051] A schematic diagram of the 4.9mm eccentricity structure can be found here. Figure 4 The type II inner rotor 5 is centered at the pump shaft input center, i.e., the origin coordinates are (0, 0, 0). The type II outer rotor 6 is offset along the eccentricity, with coordinates (0, 4.9, 0). The outer diameter center coordinates of the concentric eccentric sleeve 7 with large eccentricity are (0, 4.9, 0), and its inner diameter center coordinates are (0, 4.9, 0). The outer diameter coordinates of the eccentric interstage housing 12 with large eccentricity are (0, 4.9, 0). To ensure structural strength with a minimum radial dimension of 5.3mm for the eccentric sleeve, the outer diameter of the interstage housing is only 75mm. Compared to the outer diameter of the concentric interstage housing (84.8mm), the outer diameter reduction of the eccentric interstage housing is 9.8mm (2 × 4.9mm), which is twice the eccentricity.

[0052] Figure 13-16 illustrate the construction of an interstage housing model with a thickness of 10mm and an oil cavity depth of 5mm, while Figure 17-20 illustrate the construction of an eccentric sleeve model with a thickness of 10mm. The weight and dimensional reductions are calculated, and the radial dimensions and weights of the eccentric and concentric components are compared. The results show that the eccentric interstage housing is 28.4g lighter than the concentric interstage housing, a reduction of 24.3%; the eccentric sleeve is 34.4g lighter than the concentric sleeve, a reduction of 45.6%; and the outer diameter of both the eccentric interstage housing and the eccentric sleeve is reduced by 9.8mm, a reduction of 11.6%. See Table 1 for details. An oil pump often contains multiple interstage housings and eccentric sleeves; therefore, for oil pumps with multiple eccentricities, adopting an eccentric interstage housing structure design will significantly reduce weight.

[0053] Table 1

[0054]

[0055]

[0056] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0057] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0058] The above description is merely a specific embodiment of the present invention and is not intended to limit the present invention. Within the spirit and principles of the present invention, any person skilled in the art may use the above-disclosed technical content to make changes or modifications to equivalent embodiments and apply them to other fields. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, as well as any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.

Claims

1. A structural design method for an eccentric interstage housing lubricating pump with multiple eccentricities, characterized in that, Includes the following steps: Step 1: Determine the rotor structure of the lubricating oil pump based on the input parameters and design the eccentricity dimension; Step 2: Determine the dimensions of the lubricating oil pump housing and the internal flow channel layout based on the interface dimensions, and design the pump housing structure; Step 3: Determine the dimensions of the power input structure based on the host power input parameters, and design the pump shaft structure; Step 4: Based on the position of the inlet and outlet flow channels and the rotor structure of the lubricating oil pump, determine the input center of the pump shaft. For lubricating oil pumps with multiple eccentricities, take the size of the largest eccentricity as the reference and offset it along the position of the largest cavity to determine the center of the outer rotor with the largest eccentricity. Under the premise of ensuring the strength of the eccentric sleeve structure, design the eccentric sleeve with the largest eccentricity. Step 5: Based on the principle that all inner rotors are concentric, the center of the outer rotor can be determined according to the small eccentricity size. The outer diameter of the small eccentricity eccentric sleeve is the same as that of the large eccentricity eccentric sleeve. The small eccentricity eccentric sleeve structure is designed. Step 6: Determine the inner and outer diameter centers of the interstage housing based on the positions of the rotor and the eccentric sleeve. The inner diameter of the interstage housing is concentric with the inner rotor, and the outer diameter of the interstage housing is concentric with the outer diameter of the eccentric sleeve. Then, design the profile of the interstage housing according to the principle of covering the largest cavity, and design the eccentric interstage housing structure. Step 7: Determine the sealing requirements based on the structural location of the components and design the sealing structure of the lubricating oil pump; Step 8: Determine the error prevention scheme based on the position of the interstage housing and eccentric sleeve, and design the error prevention structure of the lubricating oil pump; Step 9: Determine the axial deformation of the oil pump based on the material expansion coefficients and boundary conditions of the oil pump housing, eccentric sleeve, and interstage housing, and design the disc structure of the oil pump. Step 10: Determine the bearing position based on the load-bearing position of the rotating component and design the lubrication channel structure.

2. The method as described in claim 1, characterized in that, It also includes step 11, after completing the structural design of steps 1-10, assembling the lubricating oil pump, conducting simulation analysis, and verifying the accuracy of the structural design.

3. A multi-eccentricity eccentric interstage housing lubricating pump designed using the method described in claim 1, characterized in that, Including Type I inner rotor, Type I outer rotor, concentric eccentric sleeve with small eccentricity, concentric interstage shell with small eccentricity, Type II inner rotor, Type II outer rotor, concentric eccentric sleeve with large eccentricity, concentric interstage shell with large eccentricity, eccentric eccentric sleeve with small eccentricity, eccentric interstage shell with small eccentricity, eccentric eccentric sleeve with large eccentricity, and eccentric interstage shell with large eccentricity.

4. The lubricating oil pump as described in claim 3, characterized in that, Type I inner rotor and Type I outer rotor are respectively installed in concentric eccentric sleeves with small eccentricity and eccentric eccentric sleeves with small eccentricity; Type II inner rotor and Type II outer rotor are respectively installed in concentric eccentric sleeves with large eccentricity and eccentric eccentric sleeves with large eccentricity. Small eccentricity concentric interstage housings are used in conjunction with Type I inner rotors, Type I outer rotors, and small eccentricity concentric eccentric sleeves; large eccentricity concentric interstage housings are used in conjunction with Type II inner rotors, Type II outer rotors, and large eccentricity concentric eccentric sleeves; small eccentricity eccentric interstage housings are used in conjunction with Type I inner rotors, Type I outer rotors, and small eccentricity eccentric sleeves; large eccentricity eccentric interstage housings are used in conjunction with Type II inner rotors, Type II outer rotors, and large eccentricity eccentric sleeves.

5. The lubricating oil pump as described in claim 4, characterized in that, The small eccentricity is 3.5 mm.

6. The lubricating oil pump as described in claim 4, characterized in that, The maximum eccentricity is 4.9 mm.

7. The lubricating oil pump as described in claim 4, characterized in that, By offsetting the rotation center of the inner rotor, the spatial positions of the inner and outer rotors are repositioned, and the eccentric sleeve is designed along the eccentricity direction based on the value of the large eccentricity.

8. The lubricating oil pump as described in claim 7, characterized in that, The interstage shell structure is designed based on the positions of the inner and outer rotors, meaning that the interstage shell is an eccentric interstage shell.

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