Lower bearing cover of rotor-type compressor pump and manufacturing method

Abstract

The present invention relates to a lower bearing cover of a rotor-type compressor pump and a manufacturing method. The lower bearing cover comprises a lower shaft sleeve and a lower flange plate, wherein the lower bearing cover is formed by compounding an insert and a lightweight material; the insert is an end ring insert and a shaft sleeve insert forming the lower shaft sleeve; and the lightweight material is an aluminum alloy or a magnesium alloy or a titanium alloy or engineering plastic, and a flange plate substrate is formed of the lightweight material. The shaft sleeve insert, the end ring insert and the lightweight material are formed by injection or die casting. The insert is made of a material in the prior art. The shaft sleeve insert ensures the wear resistance of the lower bearing cover, and the end ring insert ensures the wear resistance required for friction with a piston and an eccentric portion, and the flange plate substrate made of the lightweight material can reduce the overall weight of the lower bearing cover. Moreover, the lower bearing cover of the present invention can also reduce the overall production cost of the lower bearing cover and is conductive to energy conservation and environmental protection.

Description

A lower bearing cover for a rotary compressor pump body and its manufacturing method Cross-references to related applications

[0001] This application claims priority to Chinese Patent Application No. 202510121533.3, filed in China on January 26, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to a rotary compressor pump body, and more particularly to a lower bearing cover for a rotary compressor pump body and a method for manufacturing it. Background Technology

[0003] Rotary refrigeration compressors are widely used in household and similar air conditioners due to their high refrigeration efficiency, compact structure, and small size.

[0004] The compressor pump body is an important component of a rotary refrigeration compressor, mainly composed of a cylinder block, piston, vanes, crankshaft, upper bearing cover, and lower bearing cover. The lower bearing cover is usually made of cast iron or metallurgical parts, which results in a large weight of the lower bearing cover, which in turn leads to a large weight and rotational inertia of the entire compressor pump body.

[0005] However, replacing the lower bearing cover with a low-density material will greatly reduce the weight and rotational inertia of the entire machine, but the low-density material cannot meet the requirements for wear resistance.

[0006] Because the compressor pump body is vertically floating, under the action of gravity, the lower surface of the crankshaft eccentric shaft and the lower surface of the piston will act on the lower bearing cover. The upper surface of the lower bearing cover and the lower surfaces of the eccentric shaft and piston will form a friction surface. If a low-density material is used here, it will accelerate the wear.

[0007] In summary, achieving a lightweight design for the lower bearing cap while meeting wear resistance requirements has become an urgent problem for researchers in this field. Summary of the Invention

[0008] The technical problem to be solved by this invention is: how to achieve a lightweight design for the lower bearing cover while meeting the requirements of wear resistance;

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0010] The present invention is a lower bearing cover for a rotor compressor pump body, including a lower bushing and a lower flange plate, characterized in that the lower bearing cover is composed of an insert and a lightweight material.

[0011] Furthermore, the lightweight material is aluminum alloy, magnesium alloy, titanium alloy, or engineering plastic, and the lightweight material constitutes the flange plate base; the insert is a bushing insert constituting the lower bushing, or the insert is an end ring insert and a bushing insert constituting the lower bushing.

[0012] Furthermore, the insert is made of cast iron, cast steel, or metal profile.

[0013] Furthermore, the lower bearing cover is integrally injection-molded or die-cast from the insert and lightweight material.

[0014] Furthermore, the outer peripheral wall of the upper part of the bushing insert is provided with multiple circumferential grooves at the junction with the flange plate base, and circumferential protrusions are provided in the grooves.

[0015] Furthermore, the raised outer surface is provided with multiple vertical textures.

[0016] Furthermore, the end ring insert is a ring-shaped thin sheet with multiple blind holes on its surface facing the flange base, and the upper surface of the end ring insert is flush with the upper surface of the flange base.

[0017] Furthermore, the blind hole is adapted to the connecting member.

[0018] Furthermore, the inner diameter of the end ring insert is greater than or equal to the outer diameter of the bushing insert, and the blind hole has a thread or annular groove.

[0019] Furthermore, the upper diameter of the end ring insert is slightly smaller than the lower diameter.

[0020] This solution also relates to a method for manufacturing a lower bearing cover of a rotor compressor pump body, comprising the following steps: (1) making an injection or die-casting mold for the lower bearing cover; (2) making an insert; (3) placing and fixing the insert in the mold; (4) injecting or pressing a lightweight material as a base material into the mold, cooling and forming it, and then removing it to obtain a lower bearing cover containing the insert.

[0021] The beneficial effects of this invention are as follows: This invention relates to a lower bearing cover for a rotary compressor pump body and a manufacturing method thereof. The bushing insert and a lightweight material are injection molded or die-cast. The insert uses materials available in the prior art. The bushing insert ensures the wear resistance of the lower bearing cover, and the lightweight material flange base can reduce the overall weight of the lower bearing cover. At the same time, the lower bearing cover of this invention can also reduce the overall production cost of the lower bearing cover and is also conducive to energy conservation and environmental protection. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 is a schematic diagram of the structure of a conventional rotary compressor pump body;

[0024] Figure 2 is a vertical cross-sectional view of the bearing cover in Embodiment 1 of the present invention;

[0025] Figure 3 is a schematic diagram of the structure of the bushing insert in the bearing cover according to Embodiment 1 of the present invention;

[0026] Figure 4 is a schematic diagram of the structure of the bearing cap middle ring inlay in Embodiment 1 of the present invention;

[0027] Figure 5 is a vertical cross-sectional view of the bearing cover in Embodiment 2 of the present invention;

[0028] Figure 6 is a schematic diagram of the structure of the bushing insert in the bearing cover in Embodiment 2 of the present invention;

[0029] Figure 7 is a schematic diagram of the structure of the bearing cap middle ring inlay in Embodiment 2 of the present invention;

[0030] Figure 8 is a vertical cross-sectional view of the bearing cover in Embodiment 3 of the present invention;

[0031] Figure 9 is a structural schematic diagram of the bushing insert in the bearing cover of Embodiment 3 of the present invention;

[0032] Figure 10 is a schematic diagram of the structure of the bearing cap middle ring inlay in Embodiment 3 of the present invention.

[0033] Figure 11 is a vertical cross-sectional view of the bearing cover in Embodiment 4 of the present invention;

[0034] Figure 12 is a horizontal cross-sectional view of the bearing cover in Embodiment 4 of the present invention;

[0035] Figure 13 is a cross-sectional view of the bushing insert of Embodiment 4 of the present invention. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0037] The existing rotary compressor pump body is shown in Figure 1. The compressor pump body includes a cylinder 11, a crankshaft 2 having a long shaft 21, an eccentric portion 22, and a short shaft 23, an upper bearing cover 4 located at the top of the cylinder 11, and a lower bearing cover 5 located at the bottom of the cylinder 11. The eccentric portion 22 of the crankshaft 2 is located inside the cylinder 11, and a piston 3 is sleeved on the eccentric portion 22. The upper bearing cover 4 is composed of an upper bushing 41 and an upper flange plate 42, and is generally made of cast iron or cast steel blanks and then machined. The lower bearing cover 5 is composed of a lower bushing 51 and a lower flange plate 52, and is generally made of cast iron or cast steel blanks and then machined, or is made of suitable metal profiles; the long shaft 21 of the crankshaft 2 is located in the upper shaft hole of the upper bushing 41, and the short shaft 23 of the crankshaft 2 is located in the lower shaft hole of the lower bushing 51; and a sliding vane slot seat is provided, in which a sliding vane 8 is provided, and the end of the sliding vane 8 is sealed to the piston 3.

[0038] The lower bearing cover of Embodiment 1 of the present invention will be described in detail below with reference to Figures 2, 3, and 4. Figure 2 is a vertical sectional view of the lower bearing cover in Embodiment 1 of the present invention, Figure 3 is a vertical sectional view of the bushing insert in Embodiment 1 of the present invention, and Figure 4 is a sectional view of the end ring insert in Embodiment 1 of the present invention. The lower bearing cover 5 in Embodiment 1 of the present invention has the same structural shape as the lower bearing cover of the prior art, and is also composed of two parts: a lower bushing 51 and a lower flange plate 52. The difference is that the lower bushing 51 is composed of a bushing insert 2-51 embedded in the flange plate base 1-52, while the lower flange plate 52 is composed of the flange plate base 1-52 and an end ring insert 2-53 embedded in the flange plate base 1-52. The end ring insert 2-53 is concentrically arranged with the flange plate base 1-52. The upper surface of the base 1-52 is flush with the upper surface of the end ring insert 2-53 in the horizontal direction. The inner diameter of the end ring insert 2-53 is larger than the outer diameter of the bushing insert 2-51. The lower surface of the end ring insert 2-53 is provided with a blind hole 57. The blind hole 57 can be adapted to a connecting part 54, such as a screw, through a thread. By providing a protruding connecting part 54 on the lower surface of the end ring insert 2-53, the bonding force between the end ring insert 2-53 and the flange plate base 1-52 can be increased. The bushing insert 2-51 and the end ring insert 2-53 are made of the same material as the lower bearing cover 5 in the prior art, while the flange base 1-52 is made of lightweight materials such as aluminum alloy, magnesium alloy, titanium alloy or engineering plastic. In this way, the bushing insert 2-51 and the short shaft 23 of the crankshaft 2 can meet the wear resistance requirements, and the upper surface of the end ring insert 2-53 can also meet the wear resistance requirements of friction with the piston 3 and the lower surface of the eccentric shaft 22. The flange base 1-52, which is made of lightweight material, can meet the requirements of lightweight design of the lower bearing cover.

[0039] In a preferred embodiment, as shown in Figures 2 and 4, the upper diameter of the end ring insert 2-53 is slightly smaller than the lower diameter, that is, its outer wall is inclined, which can also increase the bonding force between the end ring insert 2-53 and the flange plate base 1-52.

[0040] Figure 3 is a cross-sectional view of the bushing insert of Embodiment 1 of the present invention, showing the general structure of the bushing insert 2-51 of Embodiment 1 of the present invention. The bushing insert 2-51 is a hollow cylindrical structure. The part of the upper outer peripheral wall of the bushing insert 2-51 that connects with the flange plate base 1-52 is provided with a circumferential lower shaft hole annular groove 54 and a lower shaft hole protrusion 55 located between the annular grooves 54. There are at least two lower shaft hole annular grooves 54. The outer surface of the lower shaft hole protrusion 55 is also provided with multiple vertical textures. During injection or die casting, a lightweight material such as aluminum alloy, magnesium alloy, titanium alloy or engineering plastic is used as the base material and is combined with the lower shaft hole protrusion 55 and annular groove 54 of the bushing insert 2-51 to avoid axial movement of the bushing insert 2-51 and the flange plate base 1-52. The vertical textures are provided, and the base material is combined with the textures to avoid circumferential rotation of the bushing insert 2-51 and the flange plate base 1-52. The hollow portion of the bushing insert forms a shaft hole portion 511, through which the short shaft 23 of the crankshaft 2 passes and generates relative friction with the inner wall of the shaft hole portion 511.

[0041] This embodiment also provides a method for manufacturing a lower bearing cover; first, an injection or die-casting mold for the lower bearing cover as shown in Figures 1 and 2 is made; second, a bushing insert 2-51 as shown in Figure 3 and an end ring insert 2-53 as shown in Figures 2 and 4 are made; third, the bushing insert 2-51 and the end ring insert 2-53 are placed and fixed in the above mold; fourth, a lightweight material such as aluminum alloy, magnesium alloy, titanium alloy or engineering plastic is injected or pressed into the mold as a base material, cooled and formed, and then removed to obtain a lower bearing cover 5 containing the above inserts.

[0042] The lower bearing cover of Embodiment 2 of the present invention will be described in detail below with reference to Figures 5, 6, and 7. Figure 5 is a vertical sectional view of the lower bearing cover in Embodiment 2 of the present invention, Figure 6 is a vertical sectional view of the bushing insert in Embodiment 2 of the present invention, and Figure 7 is a sectional view of the end ring insert in Embodiment 2 of the present invention. The lower bearing cover 5 in Embodiment 2 of the present invention has the same structural shape as the lower bearing cover of the prior art, and is also composed of two parts: a lower bushing 51 and a lower flange plate 52. The difference is that the lower bushing 51 is composed of a bushing insert 2-51 embedded in the flange plate base 1-52, while the lower flange plate 52 is composed of the flange plate base 1-52 and an end ring insert 2-53 embedded in the flange plate base 1-52. The end ring insert 2-53 is concentrically arranged with the flange plate base 1-52, and the upper surface of the flange plate base 1-52 and the upper surface of the end ring insert 2-53 are flush in the horizontal direction. The inner diameter of insert 2-53 is larger than the outer diameter of bushing insert 2-51; bushing insert 2-51 and end ring insert 2-53 are made of the same material as the lower bearing cover 5 in the prior art, while the flange base 1-52 is made of lightweight materials such as aluminum alloy, magnesium alloy, titanium alloy or engineering plastics. In this way, the bushing insert 2-51 and the short shaft 23 of crankshaft 2 can meet the wear resistance requirements, and the upper surface of end ring insert 2-53 meets the hardness requirements for friction with the piston 3 and the lower surface of eccentric shaft 22. The flange base 1-52 made of lightweight materials can meet the requirements of lightweight design of lower bearing cover.

[0043] In a preferred embodiment, the end ring insert 2-53 may also have a blind hole 57 as shown in Figure 4 of Embodiment 1, with threads or annular grooves in the blind hole 57, thereby increasing the bonding force between the end ring insert 2-53 and the flange plate base 1-52; in another preferred embodiment, as shown in Figures 5 and 7, the upper diameter of the end ring insert 2-53 is slightly smaller than the lower diameter, that is, its outer wall is inclined, which can also increase the bonding force between the end ring insert 2-53 and the flange plate base 1-52.

[0044] Figure 6 is a cross-sectional view of the bushing insert of Embodiment 2 of the present invention, showing the general structure of the bushing insert 2-51 of Embodiment 2 of the present invention. The bushing insert 2-51 is a hollow cylindrical structure. The part of the upper outer peripheral wall of the bushing insert 2-51 that connects with the flange plate base 1-52 is provided with a circumferential lower shaft hole annular groove 54 and a lower shaft hole protrusion 55 located between the annular grooves 54. There are at least two lower shaft hole annular grooves 54. The outer surface of the lower shaft hole protrusion 55 is also provided with multiple vertical textures. During injection or die casting, a lightweight material such as aluminum alloy, magnesium alloy, titanium alloy or engineering plastic is used as the base material and is combined with the lower shaft hole protrusion 55 and annular groove 54 of the bushing insert 2-51 to avoid axial movement of the bushing insert 2-51 and the flange plate base 1-52. The vertical textures are provided, and the base material is combined with the textures to avoid circumferential rotation of the bushing insert 2-51 and the flange plate base 1-52.

[0045] The hollow portion of the bushing insert forms a shaft hole portion 511, through which the short shaft 23 of the crankshaft 2 passes and generates relative friction with the inner wall of the shaft hole portion 511.

[0046] This embodiment also provides a method for manufacturing a lower bearing cover; first, an injection or die-casting mold for the lower bearing cover as shown in Figures 1 and 5 is made; second, a bushing insert 2-51 as shown in Figure 6 and an end ring insert 2-53 as shown in Figures 2 and 7 are made; third, the bushing insert 2-51 and the end ring insert 2-53 are placed and fixed in the above mold; fourth, a lightweight material such as aluminum alloy, magnesium alloy, titanium alloy or engineering plastic is injected or pressed into the mold as a base material, cooled and formed, and then removed to obtain a lower bearing cover 5 containing the above inserts.

[0047] The lower bearing cover of Embodiment 3 of the present invention will be described in detail below with reference to Figures 8, 9, and 10. Figure 8 is a vertical cross-sectional view of the lower bearing cover in Embodiment 3 of the present invention, Figure 9 is a vertical cross-sectional view of the bushing insert in Embodiment 3 of the present invention, and Figure 10 is a cross-sectional view of the end ring insert in Embodiment 3 of the present invention. In Embodiment 3 of the present invention, the lower bearing cover 5 has the same structural shape as the lower bearing cover of the prior art, and is also composed of two parts: a lower bushing 51 and a lower flange plate 52. The difference is that the lower bushing 51 is composed of a bushing insert 2-51 embedded in the flange plate base 1-52, while the lower flange plate 52 is composed of the flange plate base 1-52 and an end ring insert 2-53 embedded in the flange plate base 1-52. The end ring insert 2-53 is concentrically arranged with the flange plate base 1-52, and the upper surface of the flange plate base 1-52 is flush with the upper surface of the end ring insert 2-53 in the horizontal direction. The inner diameter of the end ring insert 2-53 is equal to the outer diameter at the stepped groove 56 of the bushing insert 2-51, and the part of the end ring insert 2-53 near the inner diameter is supported on the stepped groove 56. The bushing insert 2-51 and the end ring insert 2-53 are made of the same material as the lower bearing cover 5 in the prior art, while the flange base 1-52 is made of lightweight materials such as aluminum alloy, magnesium alloy, titanium alloy or engineering plastic. In this way, the bushing insert 2-51 and the short shaft 23 of the crankshaft 2 can meet the wear resistance requirements. The upper surface of the end ring insert 2-53 meets the wear resistance requirements for friction with the piston 3 and the lower surface of the eccentric shaft 22. The flange base 1-52, which is made of lightweight materials, can meet the requirements of lightweight design of the lower bearing cover.

[0048] In a preferred embodiment, the end ring insert 2-53 may also have a blind hole 57 as shown in Figure 4 of Embodiment 1, with threads or annular grooves in the blind hole 57, thereby increasing the bonding force between the end ring insert 2-53 and the flange plate base 1-52; in another preferred embodiment, as shown in Figures 5 and 7, the upper diameter of the end ring insert 2-53 is slightly smaller than the lower diameter, that is, its outer wall is inclined, which can also increase the bonding force between the end ring insert 2-53 and the flange plate base 1-52.

[0049] Figure 9 is a cross-sectional view of the bushing insert of Embodiment 3 of the present invention, showing the general structure of the bushing insert 2-51 of Embodiment 3 of the present invention. The bushing insert 2-51 is a hollow cylindrical structure. The part of the upper outer peripheral wall of the bushing insert 2-51 that connects with the flange plate base 1-52 is provided with a circumferential lower shaft hole annular groove 54 and a lower shaft hole protrusion 55 located between the annular grooves 54. There is at least one lower shaft hole annular groove 54. The outer surface of the lower shaft hole protrusion 55 is also provided with multiple vertical textures. During injection or die casting, a lightweight material such as aluminum alloy, magnesium alloy, titanium alloy or engineering plastic is used as the base material and is combined with the lower shaft hole protrusion 55 and annular groove 54 of the bushing insert 2-51 to avoid axial movement of the bushing insert 2-51 and the flange plate base 1-52. The vertical textures are provided, and the base material is combined with the textures to avoid circumferential rotation of the bushing insert 2-51 and the flange plate base 1-52. The hollow portion of the bushing insert forms a shaft hole portion 511, through which the short shaft 23 of the crankshaft 2 passes and generates relative friction with the inner wall of the shaft hole portion 511.

[0050] This embodiment also provides a method for manufacturing a lower bearing cover; first, an injection or die-casting mold for the lower bearing cover as shown in Figures 1 and 8 is made; second, a bushing insert 2-51 as shown in Figure 9 and an end ring insert 2-53 as shown in Figures 8 and 10 are made; third, the bushing insert 2-51 and the end ring insert 2-53 are placed and fixed in the above mold; fourth, a lightweight material such as aluminum alloy, magnesium alloy, titanium alloy or engineering plastic is injected or pressed into the mold as a base material, cooled and formed, and then removed to obtain a lower bearing cover 5 containing the above inserts.

[0051] In this embodiment, the lower bearing cover is shown in Figures 11 and 12; Figure 11 is a vertical cross-sectional view of the lower bearing cover of Embodiment 4, and Figure 12 is a horizontal cross-sectional view of the lower bearing cover of Embodiment 4. The lower bearing cover in Embodiment 4 has the same structural shape as the lower bearing cover of the prior art, and is also composed of a lower bushing and a lower flange plate. The difference is that the lower bushing is composed of a bushing insert 2-51 embedded in the flange plate base 1-52, while the lower flange plate is composed of the flange plate base 1-52. In a preferred embodiment of the present invention, the bushing insert 2-51 is made of the same material as the lower bearing cover of the prior art, while the flange plate base 1-52 is made of lightweight materials such as aluminum alloy, magnesium alloy, titanium alloy, or engineering plastics. In this way, the bushing insert 2-51 and the short shaft 23 of the crankshaft 2 can meet the wear resistance requirements, and the flange plate base 1-52 made of lightweight materials can meet the requirements of the lightweight design of the lower bearing cover.

[0052] Figure 13 is a cross-sectional view of the bushing insert in Embodiment 4, showing the general structure of the bushing insert 2-51 of the present invention. Its structure is largely the same as that in Figure 3. The bushing insert 2-51 is a hollow cylindrical structure. The portion of the upper outer peripheral wall of the bushing insert 2-51 that connects to the flange plate base 1-52 is provided with a circumferential lower shaft hole annular groove 54 and lower shaft hole protrusions 55 located between the annular grooves 54. There are at least two lower shaft hole annular grooves 54 and lower shaft hole protrusions 55. The outer surface of the bushing insert 55 is also provided with multiple vertical textures; during injection or die casting, lightweight materials such as aluminum alloy, magnesium alloy, titanium alloy or engineering plastics are used as the base material and are combined with the lower shaft hole protrusion 55 and annular groove 54 of the bushing insert 2-51 to prevent axial movement of the bushing insert 2-51 and flange plate base 1-52; the vertical textures and the combination of the base material and textures prevent circumferential rotation of the bushing insert 2-51 and flange plate base 1-52.

[0053] The hollow portion of the bushing insert forms a shaft hole portion 511, through which the short shaft 23 of the crankshaft 2 passes and generates relative friction with the inner wall of the shaft hole portion 511.

[0054] The present invention also provides a method for manufacturing a lower bearing cover; first, an injection or die-casting mold for the lower bearing cover as shown in Figures 11 and 12 is made; second, a bushing insert 2-51 as shown in Figure 13 is made; third, the bushing insert 2-51 is placed and fixed in the above mold; fourth, a lightweight material such as aluminum alloy, magnesium alloy, titanium alloy or engineering plastic is injected or pressed into the mold as a base material, cooled and formed, and then removed to obtain a lower bearing cover 5 containing the above insert.

[0055] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A lower bearing cover for a rotary compressor pump body, comprising a lower bushing and a lower flange plate, characterized in that, The lower bearing cover is composed of an insert and a lightweight material; the insert contacts the crankshaft and / or the piston; The lightweight material is aluminum alloy, magnesium alloy, titanium alloy, or engineering plastic, and the lightweight material constitutes the flange plate base; the insert is an end ring insert and a bushing insert constituting the lower bushing. The outer peripheral wall of the upper part of the bushing insert is provided with multiple circumferential grooves at the junction with the flange plate base, and circumferential protrusions are provided in the grooves; the outer surface of the protrusions is provided with multiple vertical textures; during injection or die casting, the lightweight material is used as the base material and is combined with the lower shaft hole protrusion and the groove portion of the bushing insert, thus preventing axial movement of the bushing insert and the flange plate base; the vertical textures are provided, and the base material is combined with the textures, thus preventing circumferential rotation of the bushing insert and the flange plate base; The end ring insert is a ring-shaped thin sheet with multiple blind holes on its surface facing the flange base. The blind holes have threads or annular grooves. The upper surface of the end ring insert is flush with the upper surface of the flange base. The blind holes can be adapted to the protruding coupling through threads. By providing a protruding coupling on the lower surface of the end ring insert, the bonding force between the end ring insert and the flange base can be increased. The inner diameter of the end ring insert is greater than or equal to the outer diameter of the bushing insert; The upper diameter of the end ring insert is slightly smaller than the lower diameter, and the outer wall of the end ring insert is inclined.

2. The lower bearing cover of a rotary compressor pump body according to claim 1, characterized in that, The insert is made of cast iron, cast steel or metal profile.

3. The lower bearing cover of a rotary compressor pump body according to claim 1, characterized in that, The lower bearing cap is integrally injection-molded or die-cast from the insert and lightweight material.

4. The lower bearing cover of a rotary compressor pump body according to claim 1, characterized in that, The blind hole is adapted to the connecting part.

5. A method for manufacturing the lower bearing cover of a rotary compressor pump body as described in any one of claims 1-4, characterized in that, Includes the following steps: (1) Making injection or die-casting molds for the lower bearing cover; (2) Making inlays; (3) Place and fix the insert in the above mold; (4) A lightweight material is injected or pressed into a mold as a base material, cooled and formed, and then removed to obtain a lower bearing cover containing the above-mentioned inserts.

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