Shaft current preventing motor of marine variable frequency motor

Abstract

The utility model relates to a shaft current prevention motor for a marine variable frequency motor, which belongs to the technical field of bearing protection and comprises a transmission shaft, a bearing body, a bearing inner cover and a bearing outer cover. The protection assembly comprises a bearing inner sleeve. According to the shaft current prevention motor for the marine variable frequency motor, when a transmission shaft works and shaft current generated by a bearing body is conducted, the shaft current can be blocked when encountering a first rubber insulation pad due to the special design shapes of a bearing outer sleeve and a bearing inner sleeve, and the shaft current can be prevented from being blocked when being matched with a second protection sleeve and a third protection sleeve; the protection on the shaft current is further enhanced, so that an insulating layer is formed between the end cover and the bearing sleeve, and the shaft current is prevented from burning out the bearing by passing through the bearing; the motor shell adopts a connection mode that the connecting plate and the pressing plate are mutually pressed, and the screws are used for final locking, so that the effect is better when the bearing body is protected, and the service life can be prolonged under dual protection.

Description

Technical Field

[0001] The utility model relates to the technical field of bearing protection, in particular to a marine variable-frequency motor for preventing shaft current. Background Technique

[0002] At present, the bearing assembly structures of high-voltage motors are not insulated. When the shaft current generated during the operation of the motor passes through the inner and outer rings and rollers of the bearing, a discharge phenomenon will occur, electro-corroding the bearing structure. In severe cases or after a long operation time, the bearing will be burned out, resulting in the shutdown of the motor and affecting the production of enterprises.

[0003] The mechanism of shaft current damaging the bearing: When the shaft current flows through the rolling elements and raceways of the bearing, an electric arc burns on the raceway, forming metal protrusions. After being rolled over by the rolling elements, these protrusions flatten out on both sides of the raceway to form washboard-like wrinkles. The longer the motor operates, the more obvious the wrinkles, the greater the current, and the deeper the wrinkles.

[0004] The formation of shaft current: Generally, the generation of shaft current in motors mainly occurs in large motors. The formation of shaft current is based on the existence of shaft voltage (the voltage generated between the two bearings of the motor or between the motor shaft and the bearing) and reaching a certain value, which is sufficient to break down the oil film in the bearing raceway, thereby forming shaft current. Therefore, a marine variable-frequency motor for preventing shaft current is proposed to solve the above problems. Content of the Utility Model

[0005] In view of the deficiencies of the prior art, the utility model provides a marine variable-frequency motor for preventing shaft current, which has the advantages of setting an insulating layer between the end cover and the bearing sleeve, thereby preventing shaft current from passing through the bearing and preventing the shaft current from burning out the motor bearing, etc., and solves the problem that when the shaft current generated during the operation of the motor passes through the inner and outer rings and rollers of the bearing, a discharge phenomenon will occur, electro-corroding the bearing structure, and in severe cases or after a long operation time, the bearing will be burned out.

[0006] To achieve the above object, the utility model provides the following technical solution: A marine variable-frequency motor for preventing shaft current, including a transmission shaft, a bearing body, a bearing inner cover and a bearing outer cover, and a protection component is arranged on the outer surface of the bearing body;

[0007] The protection component includes a bearing inner sleeve, the bearing inner sleeve is installed on the outer surface of the bearing body, a bearing outer sleeve is installed on the top of the bearing inner sleeve, a first rubber insulating pad is arranged between the bearing inner sleeve and the bearing outer sleeve, a second protection pad is installed on the top of the bearing outer sleeve, a motor housing is installed on the top of the bearing outer sleeve, a connecting plate is fixedly connected to the right side of the motor housing, a mounting plate is fixedly connected to the right side of the bearing outer cover, a movable rod is hinged to the top of the mounting plate, and a pressing plate is fixedly connected to the outer surface of the movable rod.

[0008] Furthermore, a W-shaped groove is provided inside the bearing inner sleeve, a protrusion which is aligned with the bearing inner sleeve is provided at the bottom of the bearing outer sleeve, and the first rubber insulating pad is located between the bearing inner sleeve and the bearing outer sleeve through the groove.

[0009] Furthermore, an L-shaped groove is provided on the top of the bearing sleeve, the motor housing is located on the top of the bearing sleeve, and the bottom of the second protective pad is attached to the bearing inner cover and the top of the bearing sleeve.

[0010] Furthermore, a third protective pad is installed on the top of the bearing outer cover and the bearing sleeve, and the third protective pad is in the shape of a Z-shaped pad.

[0011] Furthermore, the top of the mounting plate is rotatably connected with a rotating shaft, the movable rod is hinged at the top of the mounting plate through the rotating shaft, a connecting plate groove is opened inside the pressing plate, and the connecting plate is located inside the pressing plate through the connecting plate groove.

[0012] Furthermore, a mounting groove is provided on the top of the bearing sleeve, the connecting plate is located inside the bearing sleeve through the mounting groove, the internal threads of the pressure plate are connected with screws, and the connecting plate and the pressure plate are fixedly connected via the screws.

[0013] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0014] 1. The marine variable frequency motor prevents shaft current. When the transmission shaft is working, the shaft current generated by the bearing body is being conducted. The special design shape of the bearing outer sleeve and the bearing inner sleeve blocks the shaft current when it encounters the first rubber insulating pad. With the second protective sleeve and the third protective sleeve, the protection against the shaft current is further enhanced, thereby setting an insulating layer between the end cover and the bearing sleeve to prevent the shaft current from passing through the bearing and burning the motor bearing. Since the motor housing adopts a connection method in which the connecting plate and the pressure plate are crimped to each other, the screws are finally locked, which makes the bearing body more effective in protecting the bearing body and extends the service life under double protection.

[0015] 2. The marine variable frequency motor prevents shaft current by hingedly connecting the movable rod so that when the connecting plate presses the second protective pad and the third protective pad, the pressing plate can be snapped onto the outer surface of the connecting plate and fixed by screws, thereby ensuring that gaps are avoided as much as possible during secondary protection and the pressing is more secure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the main cross-sectional view of the structure of the utility model;

[0017] Figure 2 It is a partial left view of the structure of the utility model.

[0018] In the figure: 1, drive shaft; 2, bearing body; 3, bearing inner cover; 4, bearing outer cover; 5, bearing inner sleeve; 6, bearing outer sleeve; 7, first rubber insulating pad; 8, second protective pad; 9, third protective pad; 10, motor housing; 11, connecting plate; 12, mounting plate; 13, movable rod; 14, pressing plate; 15, screw. Specific embodiments

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0020] Please refer to Figures 1 to 2 , the marine variable-frequency motor for preventing shaft current in this embodiment includes a drive shaft 1, a bearing body 2, a bearing inner cover 3 and a bearing outer cover 4, and a protective component is arranged on the outer surface of the bearing body 2; the protective component includes a bearing inner sleeve 5, and the bearing inner sleeve 5 is installed on the outer surface of the bearing body 2.

[0021] A bearing outer sleeve 6 is installed on the top of the bearing inner sleeve 5. A first rubber insulating pad 7 is arranged between the bearing inner sleeve 5 and the bearing outer sleeve 6. A W-shaped groove is formed inside the bearing inner sleeve 5. A convex block corresponding to the bearing inner sleeve 5 is arranged at the bottom of the bearing outer sleeve 6. The first rubber insulating pad 7 is located between the bearing inner sleeve 5 and the bearing outer sleeve 6 through the groove. A second protective pad 8 is installed on the top of the bearing outer sleeve 6. An L-shaped groove is formed on the top of the bearing outer sleeve 6. The motor housing 10 is located on the top of the bearing outer sleeve 6. The bottom of the second protective pad 8 fits on the top of the bearing inner cover 3 and the bearing outer sleeve 6.

[0022] A third protective pad 9 is installed on the top of the bearing outer cover 4 and the bearing outer sleeve 6. The shape of the third protective pad 9 is a Z-shaped pad. The motor housing 10 is installed on the top of the bearing outer sleeve 6. A connecting plate 11 is fixedly connected to the right side of the motor housing 10. An installation plate 12 is fixedly connected to the right side of the bearing outer cover 4. A movable rod 13 is hinged to the top of the installation plate 12. A rotating shaft is rotatably connected to the top of the installation plate 12. The movable rod 13 is hinged to the top of the installation plate 12 through the rotating shaft. A pressing plate 14 is fixedly connected to the outer surface of the movable rod 13. A connecting plate groove is formed inside the pressing plate 14. The connecting plate 11 is located inside the pressing plate 14 through the connecting plate groove.

[0023] An installation groove is formed on the top of the bearing outer sleeve 6. The connecting plate 11 is located inside the bearing outer sleeve 6 through the installation groove. A screw 15 is threadedly connected inside the pressing plate 14. The connecting plate 11 and the pressing plate 14 are fixedly connected by the screw 15.

[0024] In this embodiment, the movable rod 13 is hinged so that when the connecting plate 11 presses the second protection pad 8 and the third protection pad 9, the pressure plate 14 can be snapped onto the outer surface of the connecting plate 11 and fixed by the screws 15, ensuring that gaps are avoided as much as possible during secondary protection and the compression is more secure.

[0025] In this embodiment, the bearing sleeve 6 is composed of two parts, which are externally connected by bolts to form a ring.

[0026] The working principle of the above embodiment is:

[0027] The marine variable frequency motor prevents shaft current. When the transmission shaft 1 is working, the shaft current generated by the bearing body 2 is being conducted. The special design shape of the bearing outer sleeve 6 and the bearing inner sleeve 5 blocks the shaft current when it encounters the first rubber insulating pad 7. With the second protective sleeve 8 and the third protective sleeve 9, the protection against the shaft current is further enhanced, so that an insulating layer is set between the end cover and the bearing sleeve, which prevents the shaft current from passing through the bearing and preventing the shaft current from burning the motor bearing; because the motor housing 10 adopts a connection method in which the connecting plate 11 and the pressing plate 14 are crimped to each other, the screw 15 is finally locked, so that the effect of protecting the bearing body 2 is better, and the service life can be extended under double protection.

[0028] It should be noted that the standard parts used in the application can be purchased from the market, special-shaped parts can be customized according to the description in the specification and drawings, and the specific connection methods of each part adopt mature bolts, rivets, welding, etc. in the prior art, and conventional means. Machinery, parts and equipment all adopt conventional models in the prior art; plus the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0030] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A marine variable frequency motor for preventing shaft current, comprising a transmission shaft (1), a bearing body (2), a bearing inner cover (3) and a bearing outer cover (4), characterized in that: The outer surface of the bearing body (2) is provided with a protective component; The protective component comprises a bearing inner sleeve (5), wherein the bearing inner sleeve (5) is mounted on the outer surface of the bearing body (2), a bearing outer sleeve (6) is mounted on the top of the bearing inner sleeve (5), a first rubber insulating pad (7) is arranged between the bearing inner sleeve (5) and the bearing outer sleeve (6), a second protective pad (8) is mounted on the top of the bearing outer sleeve (6), a motor housing (10) is mounted on the top of the bearing outer sleeve (6), a connecting plate (11) is fixedly connected to the right side of the motor housing (10), a mounting plate (12) is fixedly connected to the right side of the bearing outer cover (4), a movable rod (13) is hinged on the top of the mounting plate (12), and a pressure plate (14) is fixedly connected to the outer surface of the movable rod (13).

2. The marine variable frequency motor for preventing shaft current according to claim 1, characterized in that: The inner part of the bearing inner sleeve (5) is provided with a W-shaped groove, the bottom of the bearing outer sleeve (6) is provided with a convex block which is aligned with the bearing inner sleeve (5), and the first rubber insulating pad (7) is located between the bearing inner sleeve (5) and the bearing outer sleeve (6) through the groove.

3. The marine variable frequency motor for preventing shaft current according to claim 1, characterized in that: The top of the bearing sleeve (6) is provided with an L-shaped groove, the motor housing (10) is located on the top of the bearing sleeve (6), and the bottom of the second protective pad (8) is attached to the top of the bearing inner cover (3) and the bearing sleeve (6).

4. The marine variable frequency motor for preventing shaft current according to claim 1, characterized in that: A third protective pad (9) is installed on the top of the bearing outer cover (4) and the bearing sleeve (6), and the third protective pad (9) is in the shape of a Z-shaped pad.

5. The marine variable frequency motor for preventing shaft current according to claim 1, characterized in that: The top of the mounting plate (12) is rotatably connected to a rotating shaft, the movable rod (13) is hinged at the top of the mounting plate (12) via the rotating shaft, a connecting plate groove is provided inside the pressing plate (14), and the connecting plate (11) is located inside the pressing plate (14) via the connecting plate groove.

6. The marine variable frequency motor for preventing shaft current according to claim 1, characterized in that: The top of the bearing sleeve (6) is provided with a mounting groove, the connecting plate (11) is located inside the bearing sleeve (6) through the mounting groove, the internal thread of the pressure plate (14) is connected with a screw (15), and the connecting plate (11) and the pressure plate (14) are fixedly connected via the screw (15).

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