Scroll compressor bottom bearing structure and method of installing the same

Abstract

This invention discloses a bottom bearing structure for a scroll compressor and its installation method. The structure includes a main shaft and a support structure fixed to the compressor housing. A bottom bearing is sleeved on the lower end of the main shaft. The bottom bearing includes an upper structure connected to the support structure, a bearing structure sleeved outside the main shaft, and a connecting structure connecting the upper structure and the bearing structure. A lubrication structure is also provided. By fixing the entire bottom bearing to the support structure through the connecting structure and the upper structure, the bearing structure can be separated from the bottom structure of the compressor, preventing direct contact between the bottom bearing and the ground. This reduces the possibility of vibration and resonance between the compressor and the ground, lowers noise, improves overall stability, and fully utilizes the relatively small radial load and better lubrication conditions of the bottom bearing.

Description

Technical Field

[0001] This invention relates to the field of scroll compressor technology, and in particular to a bottom bearing structure for a scroll compressor and its installation method. Background Technology

[0002] Bearings and bearing assemblies are widely used in the machinery industry, including scroll compressors. A typical scroll compressor uses bearings in three locations: the main bearing, the drive bearing, and the bottom bearing. The main bearing is usually mounted on a bearing housing and bears a relatively large radial load. The drive bearing is usually mounted on the moving scroll plate and also bears a relatively large radial load. The bottom bearing is usually installed at the bottom of the main shaft and generally bears two types of loads: radial and axial. Compared to the main and drive bearings, the bottom bearing receives a relatively smaller radial load, thus its lubrication is relatively better. However, being at the bottom, the bottom bearing often bears the largest axial load; therefore, it is usually mounted directly on the bearing base.

[0003] For example, the patent document "Main Shaft for Scroll Compressor and Scroll Compressor Having the Same" disclosed in Chinese patent literature, publication number CN113586451A, includes a main shaft body with an oil guide channel running through it. An oil suction port is located at the top of the main shaft, and the bottom of the main shaft is directly connected to the bottom via a secondary bearing. Its disadvantage is that there is no buffer space between the main shaft and the bottom bearing, and the bottom bearing directly contacts the ground. This makes the vibration of the entire machine prone to resonate with the ground, generating significant noise and causing instability in the compressor.

[0004] The lubricating oil can only be drawn in from the top, which eventually leads to an excessive accumulation of lubricating oil at the bottom bearing, where the lubrication conditions are best. This prevents the lubricating oil from being directly introduced, resulting in an uneven distribution of lubricating oil. Summary of the Invention

[0005] To overcome the problem that there is no buffer space between the main shaft and the bottom bearing of existing scroll compressors, this invention provides a scroll compressor bottom bearing structure and installation method with the bottom bearing suspended.

[0006] The present invention is achieved through the following technical solution: a bottom bearing structure for a scroll compressor, comprising a main shaft and a support structure fixed to the compressor housing, wherein a bottom bearing is sleeved on the lower end of the main shaft, the bottom bearing comprising an upper structure connected to the support structure, a bearing structure sleeved on the main shaft, and a connecting structure connecting the upper structure and the bearing structure, the bearing structure having a clearance fit with the side of the main shaft, and the lower end of the bearing structure extending toward the lower end of the main shaft to form a receiving part for receiving the bottom of the main shaft.

[0007] After the bearing structure is connected to the main shaft, the entire bottom bearing is fixed to the support structure through the connecting structure and the upper structure. This allows the bearing structure to be separated from the bottom structure of the compressor, so that the bottom bearing does not have direct contact with the ground. This reduces the possibility of vibration of the whole machine and resonance with the ground, reduces noise and improves the stability of the whole machine. In addition, the setting of the support part allows the bottom bearing to withstand a certain radial load as well as axial load.

[0008] Preferably, the lower part of the bearing structure is also provided with a lubricating oil storage structure, the bottom of the main shaft is recessed to form a groove, a sleeve is provided in the groove, a blade is provided in the sleeve, and an oil passage hole is provided on the wall of the groove to connect the groove with the inner surface of the bearing structure.

[0009] When the scroll compressor is working, the main shaft rotates, causing the blades inside the casing to rotate simultaneously, generating low pressure. This draws the lubricating oil from the bottom into the casing, and then through the grooves and oil passages into the inner surface of the bearing structure for lubrication.

[0010] Preferably, the spindle is provided with a main oil passage connecting the groove to the bearing structure at the top of the spindle. The lubricating oil drawn in by the sleeve is transported to the bearing structure at the top of the spindle, such as the main bearing or drive bearing, through the main oil passage. The bottom-up lubrication passage makes full use of the characteristics of the bottom bearing having relatively small radial load and better lubrication conditions, making it easy for the lubricating oil to be drawn into the top and not easy to accumulate in the bottom.

[0011] Preferably, the inner sidewall of the bottom end of the bearing structure is recessed inward to form a bottom bearing groove, which can prevent interference between the spindle and the bearing structure and can store a portion of the lubricating oil.

[0012] Preferably, the sleeve extends from the receiving part at the bottom of the bearing structure to prevent the lubricating oil from being unable to be drawn in when the lubricating oil level is too low, thus making full use of the lubricating oil at the bottom of the lubricating oil storage structure.

[0013] Preferably, the upper structure is annular, and the connecting structure includes several connecting ribs, which are L-shaped. The annular upper structure makes the force distribution more uniform, and the several connecting ribs are evenly distributed circumferentially. The L-shaped connecting ribs increase the vertical distance between the upper structure and the bearing structure, avoiding interference with the installation of other structures and improving the installation flexibility of the bottom bearing.

[0014] Preferably, the bracket structure is fixed to the upper structure with bolts, making installation more convenient.

[0015] Preferably, the bracket structure is provided with external threads, and the inner side of the upper structure is provided with internal threads that mate with the external threads. The bracket structure is directly rotated and installed into the upper structure, which reduces the number of parts and improves the coaxiality of the bottom bearing and the main shaft.

[0016] A method for installing the bottom bearing structure of a scroll compressor as described in claims 1-7, characterized in that the installation steps include:

[0017] S1: Fit the bearing structure of the bottom bearing onto the main shaft;

[0018] S2: Align the superstructure with the support structure;

[0019] S3: Rotate the spindle so that the bottom bearing is coaxially aligned with the spindle;

[0020] S4: Secure the upper structure to the support structure firmly.

[0021] By rotating the spindle, the bottom bearing is positioned to be installed coaxially, thus ensuring the coaxial installation requirements of the spindle and the bottom bearing.

[0022] Preferably, installation step S2 further includes either step S21a or step S21b; step S21a includes tightening the bolts until the bottom bearing cannot be separated from the bracket structure; step S21b includes tightening the upper structure until the bottom bearing cannot be separated from the bracket structure. That is, depending on the different fixing methods of the bottom bearing and the bracket structure, before step S3, it is slightly tightened so that while the bottom bearing cannot be separated from the bracket structure, it can still move radially to a coaxial position when the main shaft is rotated.

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] The entire bottom bearing is fixed to the support structure via the connecting structure and the upper structure, allowing the bearing structure to be separated from the bottom structure of the compressor. This eliminates direct contact between the bottom bearing and the ground, reducing the possibility of vibration and resonance between the machine and the ground, thus lowering noise and improving overall stability. Furthermore, the support structure allows the bottom bearing to withstand certain radial and axial loads. Attached Figure Description

[0025] Figure 1 This is a three-dimensional schematic diagram of Embodiment 1 of the present invention, viewed from below the bottom bearing.

[0026] Figure 2 For Embodiment 1 of the present invention (excluding the upper and middle housing parts of the scroll compressor), from Figure 1 A schematic diagram of the cross-section after cutting at point AA;

[0027] Figure 3for Figure 2 Enlarged diagram of point B in the middle.

[0028] In the figure: spindle 1, groove 11, sleeve 2, stator support 3, bottom bearing 4, upper structure 41, bolt through hole 411, bearing structure 42, receiving part 421, bottom bearing groove 422, oil passage hole 423, connecting rib 43, blade 5. Detailed Implementation

[0029] To make the technical means, creative features, objectives and effects of this invention easier to understand, the following description, in conjunction with the accompanying drawings and specific embodiments, further explains how this invention is implemented.

[0030] Example 1, as Figure 1-3 As shown, a bottom bearing structure for a scroll compressor includes a main shaft 1 and a support structure fixed to the compressor housing. The compressor housing includes an intermediate housing, and the support structure includes a stator support 3. The outer circle of the stator support 3 and the inner hole of the intermediate housing are interference fit. The intermediate housing is heated and then assembled with the stator support 3.

[0031] A bottom bearing 4 is sleeved at the lower end of the main shaft 1. The bottom bearing 4 includes:

[0032] The upper structure 41 is connected to the support structure by bolts. The upper structure 41 is circular and has bolt through holes 411. The circular upper structure 41 makes the force more even.

[0033] The bearing structure 42 is sleeved on the outside of the spindle 1. The bearing structure 42 is clearance-fitted with the side of the spindle 1. The lower end of the bearing structure 42 extends towards the lower end of the spindle 1 to form a receiving part 421 for receiving the bottom of the spindle 1 and bearing axial load. The inner wall of the bottom end of the bearing structure 42 is recessed inward to form a bottom bearing groove 422, which can prevent the spindle 1 from interfering with the bearing structure 42 and can store a portion of lubricating oil.

[0034] The connecting structure connects the upper structure 41 and the bearing structure 42. The connecting structure includes three connecting ribs 43 that are evenly distributed axially. The connecting ribs 432 are "L" shaped, which increases the vertical distance between the upper structure 41 and the bearing structure 42, avoids interfering with the installation of other structures, and improves the installation flexibility of the bottom bearing 4.

[0035] Furthermore, a lubrication structure is also provided. A lubricating oil storage structure is also provided at the lower part of the bearing structure 42. A groove 11 is formed inward at the bottom of the main shaft 1, and a sleeve 2 is installed inside the groove 11. A blade 5 is installed inside the sleeve 2. The sleeve 2 and the groove 11 are press-fitted together. An oil passage 423 is provided on the wall of the groove 11, connecting the groove 11 to the inner surface of the bearing structure 42. A main oil passage is provided inside the main shaft 1, connecting the groove 11 to the upper bearing structure 42 of the main shaft 1.

[0036] In addition, the sleeve 2 extends out from the receiving part 421 at the lower part of the bearing structure 42 to prevent the lubricating oil from being unable to be drawn in when the lubricating oil level is too low, so as to make full use of the lubricating oil at the bottom of the lubricating oil storage structure.

[0037] The principle of the lubrication structure is as follows: When the scroll compressor is working, the main shaft 1 rotates, causing the blades inside the sleeve 2 to rotate simultaneously, generating low pressure. This draws lubricating oil from the bottom into the sleeve 2, and then through the groove 11 and oil passage 423 into the inner surface of the bearing structure 42 for lubrication. Furthermore, excess lubricating oil is transported through the main oil passage to the bearing structure 42 above the main shaft 1, such as the main shaft bearing 1 or drive bearing. This bottom-to-top lubrication path fully utilizes the relatively small radial load and better lubrication conditions of the bottom bearing, making it easy for lubricating oil to be drawn to the top and preventing it from accumulating at the bottom.

[0038] After the bearing structure 42 is connected to the main shaft 1, the entire bottom bearing 4 is fixed on the bracket structure through the connecting structure and the upper structure 41, so that the bearing structure 42 can be separated from the bottom structure of the entire compressor, so that the bottom bearing has no direct contact with the ground, reducing the possibility of vibration of the whole machine and resonance with the ground, reducing noise and improving the stability of the whole machine; in addition, the bottom bearing 4 can withstand a certain radial load and axial load through the setting of the receiving part 421.

[0039] In Embodiment 2, the bracket structure is provided with external threads, and the inner side of the upper structure 41 is provided with internal threads that mate with the external threads. Otherwise, it is the same as in Embodiment 1. The bracket structure is directly rotated and installed into the upper structure 41, reducing the number of parts while improving the coaxiality of the bottom bearing 4 and the main shaft 1.

[0040] Example 3: An installation method for the bottom bearing 4 structure 42 of the scroll compressor in Example 1, the installation steps include:

[0041] S1: Fit the bearing structure 42 of the bottom bearing 4 onto the main shaft 1;

[0042] S2: Align the upper structure 41 with the support structure;

[0043] S21a: Tightening the bolts until the bottom bearing 4 cannot be separated from the bracket structure;

[0044] S3: Rotate the main shaft 1 so that the bottom bearing 4 is coaxially aligned with the main shaft 1;

[0045] S4: Tighten the bolts to secure the upper structure 41 to the support structure.

[0046] An installation method for the bottom bearing 4 structure 42 of the scroll compressor in Embodiment 2, the installation steps include:

[0047] S1: Fit the bearing structure 42 of the bottom bearing 4 onto the main shaft 1;

[0048] S2: Align the upper structure 41 with the support structure;

[0049] S21b, Tightening the upper structure 41 until the bottom bearing 4 cannot be separated from the support structure.

[0050] S3: Rotate the main shaft 1 so that the bottom bearing 4 is coaxially aligned with the main shaft 1;

[0051] S4: Rotate the upper structure 41 to fix the upper structure 41 firmly to the support structure.

[0052] Depending on the different fixing methods of the bottom bearing 4 and the bracket structure, before step S3, it is slightly tightened so that the bottom bearing 4 cannot be separated from the bracket structure, but can still move radially to a coaxial position when the main shaft 1 is rotated. By rotating the main shaft 1, the bottom bearing 4 finds a coaxial installation position, thereby ensuring the coaxial installation requirements of the main shaft 1 and the bottom bearing 4.

Claims

1. A bottom bearing structure for a scroll compressor, comprising a main shaft and a support structure fixed to the compressor housing, characterized in that: The lower end of the main shaft is fitted with a bottom bearing. The bottom bearing includes an upper structure connected to the support structure, a bearing structure fitted outside the main shaft, and a connecting structure connecting the upper structure and the bearing structure. The bearing structure is clearance-fitted with the side of the main shaft, and the lower end of the bearing structure extends toward the lower end of the main shaft to form a receiving part for supporting the bottom of the main shaft. The lower part of the bearing structure is also provided with a lubricating oil storage structure. The bottom of the main shaft is recessed to form a groove, a sleeve is provided in the groove, a blade is provided in the sleeve, an oil passage is provided on the wall of the groove to connect the groove to the inner surface of the bearing structure, a main oil passage is provided in the main shaft to connect the groove to the bearing structure at the top of the main shaft, and a bottom bearing groove is formed by the inward recess of the inner side wall of the bottom end of the bearing structure.

2. The scroll compressor bottom bearing structure according to claim 1, characterized in that: The compressor housing includes an intermediate housing, and the support structure includes a stator support. The outer circle of the stator support and the inner hole of the intermediate housing are interference fit.

3. The scroll compressor bottom bearing structure according to claim 1, characterized in that: The sleeve extends from the receiving part at the bottom of the bearing structure.

4. The scroll compressor bottom bearing structure according to claim 1 or 3, characterized in that: The upper structure is circular, and the connecting structure includes several connecting ribs, which are "L" shaped.

5. The scroll compressor bottom bearing structure according to claim 1 or 3, characterized in that: The support structure is fixed to the upper structure by bolts.

6. The scroll compressor bottom bearing structure according to claim 5, characterized in that: The upper structure is equipped with bolt through holes.

7. A method for installing the bottom bearing structure of the scroll compressor as described in claim 6, characterized in that: The installation steps include: S1: Fit the bearing structure of the bottom bearing onto the main shaft; S2: Align the superstructure with the support structure; S3: Rotate the spindle so that the bottom bearing is coaxially aligned with the spindle; S4: Secure the upper structure to the support structure firmly.

8. The installation method of the bottom bearing structure of the scroll compressor according to claim 7, characterized in that: Installation step S2 also includes step S21a; step S21a includes: tightening the bolts until the bottom bearing cannot be separated from the bracket structure.

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