Motor insulation bearing assembly

Abstract

The utility model discloses a motor insulation bearing assembly which comprises a disc-shaped base, an outer ring fixed in the disc-shaped base, an inner ceramic ring installed at the central axis position in the outer ring and a retainer fixed at one end of the surface of the inner ceramic ring, and a plurality of balls in rolling contact with the inner wall of the outer ring are embedded in the retainer. And a polyimide insulating sleeve is coaxially sleeved in the inner ceramic ring. The outer ring, the balls, the retainer, the inner ceramic ring and the polyimide insulation sleeve are sequentially mounted in the disc-shaped base connected with the motor shell, the current insulation purpose is achieved, meanwhile, the inner ceramic ring and the polyimide insulation sleeve are sleeved with each other, the upper ends and the lower ends of the inner ceramic ring and the polyimide insulation sleeve are in bolted connection, and the purposes of quick disassembly and quick assembly are achieved.

Description

Technical Field

[0001] This utility model relates to the field of bearing technology, specifically to an insulated bearing assembly for an electric motor. Background Technology

[0002] During motor operation, especially in variable frequency drives, shaft current generation is a common and serious problem. This current can damage motor bearings and lead to motor failure. To address this issue, insulated bearings and ceramic bearings have become effective solutions. Insulated bearings use high-performance insulating materials, such as polyimide or fluoroplastics, between the inner and outer rings to prevent current from flowing through the bearing, thereby reducing wear caused by arcing. Their structure includes inner and outer rings, rolling elements, and seals, ensuring stable operation under high loads and preventing lubricant leakage. On the other hand, ceramic bearings use ceramic materials such as alumina or silicon nitride, possessing excellent electrical insulation and wear resistance, while their lightweight design makes them perform well at high speeds.

[0003] As disclosed in the patent announcement CN217010542U, a vertical motor insulating bearing sleeve structure includes a shaft, a bearing, an outer bearing end cover, an inner bearing end cover, an insulating bearing sleeve assembly, and a motor end cover. The bearing sleeve is mounted on the end of the shaft, and an insulating assembly is provided on the outer side of the bearing. The insulating assembly includes an inner bearing sleeve, an outer bearing sleeve, an insulating layer, and an insulating gasket. The inner bearing sleeve is fixedly connected to the upper and lower end covers of the bearing, and the outer bearing sleeve is fixedly connected to the motor end cover. The insulating layer separates the inner and outer bearing sleeves, blocking the shaft current from forming a circuit, thus protecting the bearing and extending its service life. However, in the above technical solution, the insulating layer is located between the inner and outer bearing sleeves and needs to withstand significant rotational friction. Long-term friction and heat accumulation will lead to aging and performance degradation of the insulating material. Especially in high-load and high-speed applications, later replacement and maintenance require disassembling the inner ring, sealing ring, and other components layer by layer until the insulating layer is removed, resulting in high maintenance costs and complexity. Utility Model Content

[0004] The purpose of this utility model is to provide an insulated bearing assembly for a motor, in which an outer ring, balls, a cage, an inner ceramic ring, and a polyimide insulating sleeve are sequentially installed inside a disc-shaped base connected to the motor housing to achieve current insulation. At the same time, the inner ceramic ring and the polyimide insulating sleeve are fitted together and bolted to the upper and lower ends to achieve quick disassembly and quick assembly, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a motor insulating bearing assembly, comprising a disc-shaped base, an outer ring fixed inside the disc-shaped base, an inner ceramic ring installed at the central axis position inside the outer ring, and a retainer fixed at one end of the surface of the inner ceramic ring. The retainer is inlaid with a plurality of balls that roll in contact with the inner wall of the outer ring. A polyimide insulating sleeve is coaxially fitted inside the inner ceramic ring. The upper and lower ends of the polyimide insulating sleeve are respectively bolted to the top and bottom ends of the inner ceramic ring. Spline grooves are provided on the inner walls of both the inner ceramic ring and the polyimide insulating sleeve.

[0006] Preferably, an annular lip plate is integrally formed on the outer wall of the disc-shaped base, and the annular lip plate has several fully penetrating positioning holes inside.

[0007] Preferably, an oil injection hole is installed on one side of the outer wall of the disc-shaped base, and an oil inlet channel communicating with the oil injection hole is provided on one side of the outer wall of the outer ring.

[0008] Preferably, both ends of the outer ring are fixed with sealing gaskets, and a secondary seal is installed inside the outer ring on the side where the two sealing gaskets are far apart from each other.

[0009] Preferably, an annular flange is integrally formed at the edge of the top of the polyimide insulating sleeve, and four equally spaced guide posts are installed at the bottom of the annular flange. The bottom of the guide posts extends into the interior of the inner ceramic ring, and an internal threaded hole is provided at the bottom of the guide posts.

[0010] Preferably, the top end of the inner ceramic ring is provided with three equally spaced internal threaded holes extending downwards, the top end of the annular flange is equipped with a first bolt, the threaded end of the first bolt extends into the interior of the internal threaded holes, the top end of the annular flange is provided with a through hole concentric with the internal threaded holes, and the bottom end of the inner ceramic ring is equipped with a second bolt for interconnecting with the internal threaded holes.

[0011] Preferably, the secondary seal consists of a C-shaped support ring and a sealing ring installed inside the support ring, with the two support rings fixed to the top and bottom of the outer ring, respectively.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: This motor insulated bearing assembly achieves current insulation by sequentially installing an outer ring, balls, a cage, an inner ceramic ring, and a polyimide insulating sleeve inside a disc-shaped base connected to the motor housing. Simultaneously, the inner ceramic ring and the polyimide insulating sleeve are interlocked and bolted together at their upper and lower ends to facilitate quick disassembly and assembly. The combined design of the inner ceramic ring and the polyimide insulating sleeve effectively prevents current from flowing through the bearing. Ceramic materials possess excellent insulation properties and can withstand high voltages, while polyimide, as a high-performance insulating material, maintains good insulation characteristics in high-temperature and high-humidity environments. This combination not only improves the insulation effect but also effectively prevents motor damage caused by current leakage, thereby extending the motor's service life. Furthermore, the bolted design at the upper and lower ends of the inner ceramic ring and the polyimide insulating sleeve allows for quick disassembly and replacement during maintenance. Maintenance personnel can quickly replace the polyimide insulating sleeve without disassembling the entire bearing, saving significant time and labor costs. Attached Figure Description

[0013] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0014] Figure 2 This is a schematic diagram of the three-dimensional cross-sectional structure of the present invention. Figure One ;

[0015] Figure 3 This is a schematic diagram of the three-dimensional cross-sectional structure of the present invention. Figure Two ;

[0016] Figure 4 This is a three-dimensional cross-sectional view of the polyimide insulating sleeve of this utility model after removal.

[0017] Figure 5 This is a schematic diagram of the three-dimensional structure of the polyimide insulating sleeve of this utility model.

[0018] In the diagram: 1. Disc-shaped base; 101. Annular lip plate; 102. Positioning hole; 103. Oil injection hole; 2. Outer ring; 3. Inner ceramic ring; 301. Internal threaded hole two; 4. Polyimide insulating sleeve; 401. Annular flange; 402. Guide post; 403. Internal threaded hole one; 404. Through hole; 5. Spline groove; 6. Cage; 7. Ball bearing; 8. Secondary seal; 9. Sealing gasket; 10. First bolt; 11. Second bolt. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0020] Please see Figures 1-5 An embodiment of this utility model provides a motor insulating bearing assembly, including a disc-shaped base 1, an outer ring 2 fixed inside the disc-shaped base 1, an inner ceramic ring 3 installed at the central axis position inside the outer ring 2, and a retainer 6 fixed at one end of the surface of the inner ceramic ring 3. The retainer 6 is inlaid with a plurality of balls 7 that roll in contact with the inner wall of the outer ring 2. A polyimide insulating sleeve 4 is coaxially fitted inside the inner ceramic ring 3. The upper and lower ends of the polyimide insulating sleeve 4 are respectively bolted to the top and bottom ends of the inner ceramic ring 3. Spline grooves 5 are provided on the inner walls of the inner ceramic ring 3 and the polyimide insulating sleeve 4.

[0021] The polyimide insulating sleeve 4 has good high temperature resistance and can maintain stable insulation effect in high temperature environment, so that the motor can still maintain good working condition under high load and high speed conditions, and reduce failures caused by excessive temperature.

[0022] The proper fit between the cage 6 and the ball bearings 7, combined with the high rigidity of the inner ceramic ring 3, can effectively improve the stability of the motor during operation. During this process, the high-rigidity inner ceramic ring 3 can withstand large radial and axial loads, and can maintain good shape stability at high speeds, reducing vibration and noise.

[0023] An annular lip plate 101 is integrally formed on the outer wall of the disc-shaped base 1. The annular lip plate 101 has several fully penetrating positioning holes 102 inside. The disc-shaped base 1 attaches the annular lip plate 101 to the front end cover of the motor, and the bolts are screwed into the disc-shaped base 1 and the front end cover of the motor through the positioning holes 102 to complete the installation operation of the disc-shaped base 1.

[0024] An oil injection hole 103 is installed on one side of the outer wall of the disc-shaped base 1. An oil inlet channel communicating with the oil injection hole 103 is provided on one side of the outer wall of the outer ring 2. Both ends of the outer ring 2 are fixed with sealing gaskets 9. A secondary seal 8 is installed inside the outer ring 2 on the side where the two sealing gaskets 9 are far apart from each other.

[0025] The secondary seal 8 consists of a C-shaped support ring and a sealing ring installed inside the support ring. The two support rings are fixed to the top and bottom of the outer ring 2 respectively. The oil filling hole 103 allows the operator to fill the cavity between the outer ring 2 and the inner ceramic ring 3 with lubricating grease. The secondary seal 8 and the sealing gasket 9 form two sealing areas between the ends of the outer ring 2 and the inner ceramic ring 3 to reduce the overflow of lubricating grease.

[0026] An annular flange 401 is integrally formed at the edge of the top of the polyimide insulating sleeve 4. Four equally spaced guide posts 402 are installed at the bottom of the annular flange 401. The bottom of the guide posts 402 extends into the interior of the inner ceramic ring 3. An internal threaded hole 403 is provided at the bottom of the guide posts 402. Three equally spaced internal threaded holes 301 are provided at the top of the inner ceramic ring 3. A first bolt 10 is installed at the top of the annular flange 401. The threaded end of the first bolt 10 extends into the interior of the internal threaded hole 301. A through hole 404 concentric with the internal threaded hole 301 is provided at the top of the annular flange 401. A second bolt 11 for interconnection with the internal threaded hole 403 is installed at the bottom of the inner ceramic ring 3.

[0027] Each guide post 402 at the bottom of the annular flange 401 is inserted into the inner ceramic ring 3. At this time, the through hole 404 and the second internal threaded hole 301 are concentric. The worker can screw the first bolt 10 into the second internal threaded hole 301. At this time, the upper end of the inner ceramic ring 3 and the polyimide insulating sleeve 4 are fixed. The second bolt 11 is screwed from the bottom of the inner ceramic ring 3 into the first internal threaded hole 403 of the guide post 402 until it is tightened. Then the second bolt 11 fixes the lower end of the inner ceramic ring 3 and the polyimide insulating sleeve 4.

[0028] In this embodiment, the operator first bolts the disc-shaped base 1 to the front end cover of the motor, and then coaxially assembles the motor drive shaft with the disc-shaped base 1 and the polyimide insulating sleeve 4. During this process, the motor drive shaft and the polyimide insulating sleeve 4 engage through the spline groove 5, allowing the motor drive shaft to rotate the inner ceramic ring 3 and the polyimide insulating sleeve 4 via the spline and spline groove 5. At this time, the inner ceramic ring 3 rolls against the outer ring 2 through the cage 6 and the ball bearings 7, and the cooperation between the inner ceramic ring 3 and the polyimide insulating sleeve 4 achieves the purpose of insulation. When the operator needs to disassemble or replace the polyimide insulating sleeve 4, the operator removes the disc-shaped base 1 from the... Remove the front cover of the motor and separate it from the motor drive shaft. Then, unscrew the first bolt 10 and the second bolt 11 from the top and bottom of the inner ceramic ring 3 to release the connection restriction of the second bolt 11 and the first bolt 10 on the inner ceramic ring 3 and the polyimide insulating sleeve 4. Then, remove the polyimide insulating sleeve 4 from the inner ceramic ring 3. Use a cleaning agent and cloth to clean the polyimide insulating sleeve 4 and its contact surfaces to remove dirt and grease. This helps to ensure that the contact surfaces are clean and flat during reinstallation, which is beneficial to the insulation effect. Carefully check the polyimide insulating sleeve for wear, cracks or other damage. If damage is found, it should be replaced in time and the new polyimide insulating sleeve 4 should be installed into the inner ceramic ring 3 by reversing the operation.

Claims

1. A motor insulating bearing assembly, characterized in that: The device includes a disc-shaped base (1), an outer ring (2) fixed inside the disc-shaped base (1), an inner ceramic ring (3) installed at the central axis position inside the outer ring (2), and a retainer (6) fixed at one end of the surface of the inner ceramic ring (3). The retainer (6) is inlaid with several balls (7) that roll in contact with the inner wall of the outer ring (2). The inner ceramic ring (3) is coaxially fitted with a polyimide insulating sleeve (4). The upper and lower ends of the polyimide insulating sleeve (4) are respectively bolted to the top and bottom ends of the inner ceramic ring (3). Spline grooves (5) are provided on the inner walls of the inner ceramic ring (3) and the polyimide insulating sleeve (4).

2. The motor insulating bearing assembly according to claim 1, characterized in that: The outer wall of the disc-shaped base (1) is integrally formed with an annular lip plate (101), and the interior of the annular lip plate (101) is provided with several fully penetrating positioning holes (102).

3. The motor insulating bearing assembly according to claim 2, characterized in that: An oil injection hole (103) is installed on one side of the outer wall of the disc-shaped base (1), and an oil inlet channel communicating with the oil injection hole (103) is provided on one side of the outer wall of the outer ring (2).

4. The motor insulating bearing assembly according to claim 1, characterized in that: Both ends of the outer ring (2) are fixed with sealing gaskets (9), and a secondary seal (8) is installed inside the outer ring (2) on the side where the two sealing gaskets (9) are far apart from each other.

5. A motor insulating bearing assembly according to claim 1, characterized in that: An annular flange (401) is integrally formed at the edge of the top of the polyimide insulating sleeve (4). Four equally spaced guide posts (402) are installed at the bottom of the annular flange (401). The bottom of the guide posts (402) extends into the interior of the inner ceramic ring (3). An internal threaded hole (403) is provided at the bottom of the guide posts (402).

6. A motor insulating bearing assembly according to claim 5, characterized in that: The top end of the inner ceramic ring (3) is provided with three equally spaced internal threaded holes (301) extending downwards. The top end of the annular flange (401) is equipped with a first bolt (10), the threaded end of the first bolt (10) extending into the interior of the internal threaded holes (301). The top end of the annular flange (401) is provided with a through hole (404) concentric with the internal threaded holes (301). The bottom end of the inner ceramic ring (3) is equipped with a second bolt (11) for interconnection with the internal threaded hole (403).

7. A motor insulating bearing assembly according to claim 4, characterized in that: The secondary seal (8) consists of a support ring with a C-shaped cross section and a sealing ring installed inside the support ring. The two support rings are fixed to the top and bottom of the outer ring (2), respectively.

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