End cover mechanism capable of eliminating shaft current

Abstract

The utility model relates to the technical field of motors, in particular to an end cover mechanism capable of eliminating shaft current, which comprises a rotating shaft, a bearing sleeving part for sleeving a bearing is arranged on the rotating shaft, a bearing inner ring of the bearing is sleeved with the bearing sleeving part, a bearing outer ring of the bearing is sleeved with a bearing support, and the bearing outer ring of the bearing is sleeved with the bearing support. The outer side of the bearing support is sleeved with a support outer sleeve for limiting, and the support outer sleeve is connected with an end cover. An insulating film layer is arranged between the bearing support and the support jacket; the rotating shaft is located at the axis position of the bearing, the bearing support, the support outer sleeve and the end cover. The end cover mechanism is simple in structure, easy to assemble, compact in connection and small in occupied space, and the service life of equipment can be effectively prolonged while the influence of shaft current is effectively eliminated.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to an end cover mechanism capable of eliminating shaft current. Background Art

[0002] With the development of frequency conversion technology, frequency conversion motors are increasingly being used. When a motor is powered by a frequency converter, in addition to the asymmetric magnetic circuit, static electricity accumulation, and shaft voltage caused by high-frequency voltage, a new bearing current source will also be introduced - the common mode voltage of the frequency converter.

[0003] The common mode voltage is divided by layers of parasitic capacitance and finally distributed to both ends of the bearing in a certain ratio. When the voltage established at both ends of the bearing exceeds the insulation capacity of the lubricating oil film, current will flow through the bearing, that is, a loop shaft current is formed between "shaft-bearing-base-other end bearing", such as Figure 1 shown.

[0004] To prevent bearing current, appropriate wiring and grounding systems can be adopted, such as changing the bearing current loop and weakening the common mode voltage. These measures are all aimed at reducing the voltage value across the bearing lubricating film so that it does not cause bearing current pulses, but they are likely to shorten the bearing life.

[0005] In addition, in order to reduce manufacturing costs in practical applications, insulating bearings, filters, and additional grounding positions are often used to reduce shaft current interference. However, this method invisibly makes the structure of the end cover more complicated, which not only affects assembly but also increases costs.

[0006] Therefore, a new technical solution is urgently needed to solve the above technical problems. Utility Model Content

[0007] The purpose of the utility model is to overcome the above-mentioned problems of the prior art and to provide an end cover mechanism that can eliminate shaft current, so as to solve the technical problem that the existing motor technology cannot effectively solve the influence of shaft current caused by large motors or variable frequency motors started by inverters at low cost.

[0008] The above objectives are achieved through the following technical solutions:

[0009] An end cover mechanism capable of eliminating shaft current comprises a rotating shaft, a bearing sleeve portion for a bearing to be sleeved is arranged on the rotating shaft, a bearing inner ring of the bearing is sleeved with the bearing sleeve portion, a bearing outer ring of the bearing is sleeved with a bearing support, a support outer sleeve is sleeved on the outer side of the bearing support for position limiting, and the support outer sleeve is connected to the end cover;

[0010] An insulating film layer is provided between the bearing support and the support outer sleeve;

[0011] The rotating shaft is located at the axial center position of the bearing, the bearing support, the support sleeve and the end cover.

[0012] Furthermore, the bearing sleeve connection portion includes a bearing ring groove with an L-shaped cross-section, and a retaining ring groove for retaining rings to be engaged is opened on the bottom wall of the bearing ring groove. The ring groove side walls of the bearing ring groove, the bottom wall of the bearing ring groove and the retaining ring groove constitute an installation space for the bearing inner ring to be sleeved. After the retaining ring is engaged with the retaining ring groove, it is used to limit and block the outer side of the bearing inner ring.

[0013] Furthermore, the bearing is a ball bearing.

[0014] Further, the bearing support is Z-shaped, comprising an annular support body, an annular support inner retaining ring is arranged along the inner wall of the outer port of the annular support body, and an annular support outer retaining ring is arranged along the outer wall of the inner port of the annular support body;

[0015] The inner wall of the annular support body is sleeved on the outer wall of the bearing outer ring, and the inner retaining ring of the annular support is used to limit and block the outer side of the bearing outer ring; the width of the inner retaining ring of the annular support is not greater than the width of the bearing outer ring.

[0016] Further, the support sleeve is Z-shaped, comprising an annular sleeve body, an annular sleeve inner retaining ring is arranged along the inner wall of the outer port of the annular sleeve body, and an annular sleeve outer retaining ring is arranged along the outer wall of the inner port of the annular support body;

[0017] The inner wall of the annular sleeve body is sleeved on the outer wall of the annular support outer ring, and the inner wall of the annular sleeve inner ring is sleeved on the outer wall of the annular support body.

[0018] Furthermore, the insulating film layer is respectively wound around the outer wall of the annular support body and the outer wall of the annular support outer retaining ring.

[0019] Furthermore, the insulating film layer is a polyimide film.

[0020] Furthermore, a mica plate annular groove for mounting a hard mica plate is formed between the outer retaining ring of the annular support and the inner retaining ring of the annular outer sleeve.

[0021] Furthermore, the hard mica plate is annular and sleeved on the outer wall of the annular support body.

[0022] Furthermore, a plurality of first screw holes are arranged along the circumferential direction on the inner retaining ring of the annular sleeve, and correspondingly, a plurality of second screw holes are arranged along the circumferential direction on the end cover, and the first screw holes are connected with the second screw holes by screws to realize the connection between the support sleeve and the end cover.

[0023] Beneficial Effects

[0024] The utility model provides an end cover mechanism capable of eliminating shaft current, which can effectively solve the technical problem of shaft current influence caused by large motors or variable frequency motors started by frequency converters. The end cover mechanism has a simple structure, is easy to assemble, has a compact connection and does not take up space. While effectively eliminating the influence of shaft current, it can effectively increase the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a loop shaft current formed between the shaft-bearing-base-the other end bearing in the prior art;

[0026] Figure 2 This is a first-view structural schematic diagram of an end cover mechanism capable of eliminating shaft current according to the utility model;

[0027] Figure 3 This is a second perspective structural schematic diagram of an end cover mechanism capable of eliminating shaft current according to the utility model;

[0028] Figure 4 This is an exploded view of an end cover mechanism capable of eliminating shaft current according to the utility model;

[0029] Figure 5 It is a cross-sectional view of an end cover mechanism capable of eliminating shaft current according to the utility model;

[0030] Figure 6 The utility model is a schematic diagram of the connection structure between the bearing support and the support sleeve in the end cover mechanism capable of eliminating shaft current.

[0031] Graphic marking:

[0032] 1-rotating shaft, 101-bearing sleeve connection part, 102-bearing ring groove, 103-circlip ring groove, 104-ring groove side wall;

[0033] 2-bearing, 201-bearing inner ring, 202-bearing outer ring;

[0034] 3-bearing support, 301-annular support body, 302-annular support inner retaining ring, 303-annular support outer retaining ring;

[0035] 4-support jacket, 401-annular jacket body, 402-annular jacket inner retaining ring, 403-annular jacket outer retaining ring;

[0036] 5-end cap;

[0037] 6-insulating film layer;

[0038] 7-circlip;

[0039] 8-Hard mica board;

[0040] 9-mica plate ring groove;

[0041] 10- annular chamfer;

[0042] 11-first screw hole;

[0043] 12-second screw hole;

[0044] 13-Epoxy resin. DETAILED DESCRIPTION

[0045] The utility model is further described in detail below based on the accompanying drawings and embodiments. The described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0046] like Figures 2 to 5 As shown, an end cover mechanism that can eliminate shaft current is suitable for some large motors or variable frequency motors started by a frequency converter. The end cover 5 in the scheme is more suitable for use at the floating end of the motor; by forming a circuit break for the motor end cover, the circuit generated by the shaft current is cut off. The mechanism includes a rotating shaft 1, on which a bearing sleeve 101 for the bearing 2 to be sleeved is provided, the bearing inner ring 201 of the bearing 2 is sleeved with the bearing sleeve 101, the bearing outer ring 202 of the bearing 2 is sleeved with a bearing support 3, the outer side of the bearing support 3 is sleeved with a support sleeve 4 for limiting, and the support sleeve 4 is connected to the end cover 5;

[0047] An insulating film layer 6 is provided between the bearing support 3 and the support jacket 4;

[0048] The rotating shaft 1 is located at the axial center position of the bearing 2, the bearing support 3, the support sleeve 4 and the end cover 5.

[0049] like Figure 4 and 5 As shown, the bearing sleeve portion 101 in this embodiment includes a bearing ring groove 102 with an L-shaped cross section, and a circlip ring groove 103 for the circlip 7 to be clamped is opened on the bottom wall of the bearing ring groove 102. The ring groove side wall 104 of the bearing ring groove 102, the bottom wall of the bearing ring groove 102 and the circlip ring groove 103 form an installation space for the bearing inner ring 201 to be sleeved. After the circlip 7 is clamped with the circlip ring groove 103, it is used to limit and block the outer side of the bearing inner ring 201;

[0050] The width of the retaining ring 7 is not greater than the width of the bearing outer ring 202 .

[0051] It should be noted that the bearing 2 described in this embodiment is a ball bearing.

[0052] As a specific introduction to the bearing support 3 described in this embodiment, Figure 4 and 5 As shown, the bearing support 3 is Z-shaped, including an annular support body 301, an annular support inner retaining ring 302 is arranged along the inner wall of the outer port of the annular support body 301, and an annular support outer retaining ring 303 is arranged along the outer wall of the inner port of the annular support body 301;

[0053] Specifically, the inner wall of the annular support body 301 is sleeved on the outer wall of the bearing outer ring 202, and the annular support inner retaining ring 302 is used to limit and block the outer side of the bearing outer ring 202;

[0054] Wherein, the width of the annular support inner retaining ring 302 is not greater than the width of the bearing outer ring 202 .

[0055] As a specific introduction to the support housing 4 in this embodiment, Figure 4 and 5 As shown, the support sleeve 4 is Z-shaped, including an annular sleeve body 401, an annular sleeve inner retaining ring 402 is arranged along the inner wall of the outer port of the annular sleeve body 401, and an annular sleeve outer retaining ring 403 is arranged along the outer wall of the inner port of the annular support body 301;

[0056] Specifically, the inner wall of the annular sleeve body 401 is sleeved on the outer wall of the annular support outer retaining ring 303 , and the inner wall of the annular sleeve inner retaining ring 402 is sleeved on the outer wall of the annular support body 301 .

[0057] like Figure 6 As shown, in this embodiment, the interference structure between the insulating film layer 6 and the bearing support 3 is as follows: the insulating film layer 6 is wound around the outer wall of the annular support body 301 and the outer wall of the annular support outer retaining ring 303 respectively.

[0058] In this embodiment, the insulating film layer 6 is a polyimide film;

[0059] Specifically, the polyimide film is a high-temperature resistant electrical insulation material for motors and electrical appliances. In this embodiment, the thickness of the polyimide film is 0.125 mm, and two layers of the film are sufficient.

[0060] Assembly instructions: Place the support sleeve 4 in a hot oven at 180°C for 2 hours (the time and temperature are set according to different materials and sizes), and then press the bearing support 3 wrapped with polyimide film into it. After cooling, connect the bearing support 3 and the support sleeve 4 as a whole to the bearing 2 and the end cover 5.

[0061] In addition, if Figure 6 As shown, this mechanism forms a mica plate annular groove 9 for mounting a hard mica plate 8 between the annular support outer retaining ring 303 and the annular outer sleeve inner retaining ring 402;

[0062] Specifically, the hard mica board 8 in this embodiment is made of mica sheets glued with shellac or glycerin resin, and is made by hot pressing and thickness calibration. It is an insulating material with a heat resistance grade of B.

[0063] The hard mica plate 8 is annular and is sleeved on the outer wall of the annular support body 301 . The thickness is about 1 to 2 mm and the hard mica plate 8 is sleeved on the outer wall of the annular support body 301 by heat-shrink sleeve.

[0064] In the present embodiment, annular chamfers 10 are provided on the outer edges of the bearing support 3 and the support sleeve 4, and the joints of two adjacent annular chamfers 10 are sealed by epoxy resin 13. Specifically, the model of the epoxy resin 13 in the present embodiment is 381-4DZ, which is a room temperature curing product with a heat resistance grade of F.

[0065] As a connection method between the support housing 4 and the end cover 5, Figures 2 to 4 As shown, in this embodiment, a plurality of first screw holes 11 are arranged along the circumferential direction on the inner retaining ring 402 of the annular sleeve, and correspondingly, a plurality of second screw holes 12 are arranged along the circumferential direction on the end cover 5. The first screw holes 11 are connected with the second screw holes 12 by screws, so as to realize the connection between the support sleeve 4 and the end cover 5.

[0066] The above description is only for illustrating the implementation mode of the present invention and is not intended to limit the present invention. For those skilled in the art, any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An end cap mechanism capable of eliminating shaft current, characterized in that: The invention comprises a rotating shaft (1), wherein a bearing sleeve portion (101) for sleeve-engaging a bearing (2) is arranged on the rotating shaft (1), a bearing inner ring (201) of the bearing (2) is sleeve-engaged with the bearing sleeve portion (101), a bearing outer ring (202) of the bearing (2) is sleeve-engaged with a bearing support (3), a support sleeve (4) is sleeved on the outer side of the bearing support (3) for limiting position, and the support sleeve (4) is connected to an end cover (5); An insulating film layer (6) is provided between the bearing support (3) and the support jacket (4); The rotating shaft (1) is located at the axial center of the bearing (2), the bearing support (3), the support sleeve (4) and the end cover (5).

2. The end cover mechanism capable of eliminating shaft current according to claim 1, characterized in that: The bearing sleeve connection portion (101) includes a bearing ring groove (102) with an L-shaped cross-section, and a retaining ring groove (103) for retaining a retaining ring (7) to be engaged is provided on the bottom wall of the bearing ring groove (102). An installation space for the bearing inner ring (201) to be sleeved is formed between the ring groove side wall (104) of the bearing ring groove (102), the bottom wall of the bearing ring groove (102) and the retaining ring groove (103). After the retaining ring (7) is engaged with the retaining ring groove (103), it is used to limit and block the outer side of the bearing inner ring (201).

3. An end cover mechanism capable of eliminating shaft current according to claim 1 or 2, characterized in that: The bearing (2) is a ball bearing.

4. The end cap mechanism capable of eliminating shaft current according to claim 1, characterized in that: The bearing support (3) is Z-shaped, comprising an annular support body (301), an annular support inner retaining ring (302) is arranged along the inner wall of the outer port of the annular support body (301), and an annular support outer retaining ring (303) is arranged along the outer wall of the inner port of the annular support body (301); The inner wall of the annular support body (301) is sleeved on the outer wall of the bearing outer ring (202), and the annular support inner retaining ring (302) is used to limit and block the outer side of the bearing outer ring (202); the width of the annular support inner retaining ring (302) is not greater than the width of the bearing outer ring (202).

5. The end cover mechanism capable of eliminating shaft current according to claim 4, characterized in that: The support sleeve (4) is Z-shaped, comprising an annular sleeve body (401), an annular sleeve inner retaining ring (402) is arranged along the inner wall of the outer port of the annular sleeve body (401), and an annular sleeve outer retaining ring (403) is arranged along the outer wall of the inner port of the annular support body (301); The inner wall of the annular sleeve body (401) is sleeved on the outer wall of the annular support outer retaining ring (303), and the inner wall of the annular sleeve inner retaining ring (402) is sleeved on the outer wall of the annular support body (301).

6. The end cover mechanism capable of eliminating shaft current according to claim 5, characterized in that: The insulating film layer (6) is respectively wound around the outer wall of the annular support body (301) and the outer wall of the annular support outer retaining ring (303).

7. The end cap mechanism capable of eliminating shaft current according to claim 6, characterized in that: The insulating film layer (6) is a polyimide film.

8. The end cap mechanism capable of eliminating shaft current according to claim 5, characterized in that: A mica plate annular groove (9) for mounting a hard mica plate (8) is formed between the annular support outer retaining ring (303) and the annular outer sleeve inner retaining ring (402).

9. The end cover mechanism capable of eliminating shaft current according to claim 8, characterized in that: The hard mica plate (8) is annular and sleeved on the outer wall of the annular support body (301).

10. The end cover mechanism capable of eliminating shaft current according to claim 5, characterized in that: A plurality of first screw holes (11) are arranged on the inner retaining ring (402) of the annular sleeve along the circumferential direction, and correspondingly, a plurality of second screw holes (12) are arranged on the end cover (5) along the circumferential direction. The first screw holes (11) are connected with the second screw holes (12) by screws, so as to realize the connection between the support sleeve (4) and the end cover (5).

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