CN218771606U - Motor shaft grounding structure - Google Patents

Abstract

The utility model provides a motor shaft ground structure, includes electric motor rotor axle, motor casing and ground ring, wherein is provided with between electric motor rotor axle and the motor casing and holds the chamber, ground ring fixed mounting hold in the chamber and with electric motor rotor axle sliding connection to make and form the electric current route between electric motor rotor axle, ground ring and the motor casing, hold the intracavity and provide lubricated medium and provide the lubrication for the contact surface of electric motor rotor axle and ground ring. This ground structure can effectively reduce the wearing and tearing of ground ring, improves motor ground structure's life, reduces the maintenance cost.

Description

Motor shaft grounding structure

Technical Field

The utility model belongs to the motor field, concretely relates to motor shaft ground structure.

Background

The current fault of a motor bearing has great harm to the motor, the service life of the bearing is greatly shortened, obvious noise and vibration can occur even after the motor runs for several days under certain conditions, and the bearing can be burnt out even within minutes under the condition that the shaft current is serious in a high-power motor. Therefore, the bearing grounding structure is arranged, current on the motor rotor shaft is guided to the motor shell to be prevented from passing through the rotor bearing, and the motor grounding structure plays an important role in prolonging the service life of the motor. The conventional motor shaft grounding structure adopts a carbon ring arranged between a motor rotor shaft and a bearing support to lead out current on the motor rotor shaft, but the carbon ring is easily worn in the process, and additional friction loss is caused to reduce the efficiency of the motor. Therefore, the motor shaft grounding structure which is not easy to wear has higher practical value for reducing the maintenance cost of the motor and improving the motor efficiency.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a motor shaft ground structure can be for a long time be on active service difficult wearing and tearing.

According to the utility model discloses an embodiment provides a motor shaft ground structure, including motor rotor axle, motor casing and ground ring, wherein the motor rotor axle with be provided with between the motor casing and hold the chamber, it is used for fixed mounting to be provided with connecting portion in the chamber to hold ground ring, ground ring with the contact surface of motor rotor axle becomes relative slip rotation so that form the electric current route between motor rotor axle, ground ring and the motor casing, it provides lubricating medium for to hold the intracavity ground ring with the contact surface of motor rotor axle provides the lubrication.

The motor rotor shaft and the grounding ring are in clearance fit, the contact surface of the motor rotor shaft and the grounding ring is provided with lubricating media for providing lubrication, so that the abrasion between the motor rotor shaft and the grounding ring is effectively reduced, the service life of the grounding structure is prolonged, and meanwhile, a current path is allowed to be formed between the motor rotor shaft and the grounding ring so as to lead current on the motor rotor shaft out to a motor shell to protect a motor bearing.

Further, the grounding ring comprises a carbon ring and a conductive wear-resistant layer, and the conductive wear-resistant layer is coated on the radial inner surface and the radial outer surface of the carbon ring. The conductive wear-resistant layer can protect the carbon ring, reduce the wear rate of the grounding ring and prolong the service life.

Further, the conductive wear layer is configured as a metal layer. The conductive wear-resistant layer is provided with the metal layer, so that the conductive wear-resistant layer has good conductivity while having wear resistance, and is convenient to process and low in cost.

Further, the conductive wear-resistant layer completely covers the surface of the carbon ring. The conductive wear-resistant layer is completely coated on the surface of the carbon ring, so that the processing is convenient, and the wear-resistant layer can be prevented from falling off.

Further, the connecting portion is configured to be fixedly connected to the metal bracket in the accommodating cavity. The metal bracket is connected with the conductive part, so that the conductive performance is improved, and the parts are convenient to replace.

Further, the metal support comprises an axial limiting mechanism for axially limiting the grounding ring. The axial limiting mechanism can avoid damage caused by axial dislocation of the grounding ring in the long-term service process.

Furthermore, the axial limiting mechanism comprises a clamping ring clamped on the metal support and an annular boss protruding from the surface of the metal support. The clamping ring can be detached to enable the grounding ring to be installed from one side of the clamping ring and abut against the annular boss, and then the clamping ring is installed to achieve positioning.

Further, the metal bracket is fixedly connected in the accommodating cavity through a bolt. The bolt connection is firm, and the part replacement is convenient.

Further, the lubricating medium is configured as lubricating oil. The working environment of the motor rotor shaft is provided with lubricating oil, and the lubricating oil is used for lubricating the grounding ring, so that the method is simple and easy to realize.

Further, the motor rotor shaft is configured as a hollow shaft, lubricating oil is provided in the motor rotor shaft, the motor rotor shaft is provided with a lubricating oil flow passage, and the accommodating cavity is communicated with a shaft inner cavity of the motor rotor through the lubricating oil flow passage so as to allow the lubricating oil to flow into the accommodating cavity. The lubricating oil in the motor rotor shaft is used for lubricating without complex adjustment of the structure, and the structure is simple.

Further, an opening of the lubricating oil flow passage in the accommodating cavity is provided at a mounting position of the ground ring. The lubricating oil runner is arranged at the position of the grounding ring, so that lubricating oil can be fully infiltrated to the grounding ring, and the loss of the lubricating oil is reduced.

Drawings

FIG. 1 is a schematic diagram of a motor shaft grounding structure in a pair of scales;

FIG. 2 is a schematic view of a motor shaft grounding structure according to an embodiment;

FIG. 3 is a schematic view of a portion of the enlarged area A in FIG. 2;

FIG. 4a is a schematic diagram of an embodiment of a ground ring;

FIG. 4b is a schematic diagram of a circumferential cross-sectional structure of the ground ring in an embodiment.

The drawings are for the purpose of illustrating the invention in detail so that those skilled in the art can understand the technical idea of the invention and are not intended to limit the invention. For the sake of clarity, the drawings described above only schematically illustrate the structures relating to the technical features of the invention, without showing the complete apparatus and all the details strictly to the actual scale.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description of preferred embodiments thereof, which is illustrated in the accompanying drawings.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment herein. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive. Those skilled in the art will appreciate that embodiments described herein may be combined with other embodiments without structural conflict.

In the description herein, unless otherwise expressly specified or limited, the terms "mounted," "connected," and the like are to be construed broadly, as meaning both movably connected and fixedly connected or integral to each other. The specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.

In the description herein, terms indicating orientation or positional relationship, such as "upper," "lower," "left," "right," "lateral," "longitudinal," "height," "length," "width," and the like, are intended to accurately describe embodiments and to simplify description, but are not intended to limit the referenced parts or structures to a particular orientation, to be mounted or operated in a particular orientation, and are not to be construed as limiting the embodiments herein.

In order to avoid the damage of the motor bearing caused by the current of the motor bearing, a grounding device is needed to lead the current on the motor rotor shaft out of the motor shell. At present, a common design is shown in a comparative example in fig. 1, a rotor shaft 1 of an electric machine is connected with a bearing seat 3 through a roller bearing 2, wherein the bearing seat 3 is fixedly connected with a shell of the electric machine or configured into an integral structure, and can be regarded as a part of the shell of the electric machine. In order to avoid that the current on the motor rotor shaft 1 flows through the roller bearing 2 causing damage to the roller bearing 2, the motor rotor shaft 1 needs to be grounded. Bearing frame 3 and motor casing fixed connection or an organic whole of motor, the tip is provided with ground ring 4, and ground ring 4 adopts the carbocycle to with sliding contact between the motor rotor axle 1, thereby form the electric current route between motor rotor axle 1, ground ring 4, bearing frame 3, derive the electric current on the motor rotor axle 1 to motor casing formation ground connection. However, in this design, the grounding ring 4 and the motor rotor shaft 1 are in a dry friction state, the grounding ring 4 is easily and rapidly worn, and the friction force between the grounding ring 4 and the motor rotor shaft 1 causes power loss to reduce the efficiency of the motor.

In order to solve the above problem, an embodiment of the present invention provides a motor shaft grounding structure as shown in fig. 2, including motor rotor shaft 1, bearing frame 3 and grounding ring 4, wherein there is one between motor rotor shaft 1 and the motor casing to hold chamber 6, should hold the chamber in this embodiment and be injectd jointly by motor casing, bearing frame 3 and motor rotor shaft 1 and provide, wherein bearing frame 3 can be the independent part that is fixed in motor casing and also can become the integral type structure with motor casing, grounding ring 4 fixed connection holds in chamber 6 and becomes relative slip rotation on the contact surface with motor rotor shaft 1, there is lubricating medium to fill between grounding ring 4 and motor rotor shaft 1 in holding chamber 6, make and constitute the electric current route between motor rotor shaft 1, grounding ring 4, the bearing frame 3, thereby derive the electric current on the motor rotor shaft 1. In a preferred embodiment, the lubricating medium is lubricating oil from the lubricating system of the motor itself, which forms a thin oil film between the grounding ring 4 and the motor rotor shaft 1, which provides lubrication to the relative sliding surfaces of the grounding ring 4 and the motor rotor shaft 1 while not affecting the electrical conduction to avoid wear of the grounding ring. In other embodiments, the lubricating medium may be a water-based lubricant or grease, etc.

The specific structure in the area a in fig. 2 is as shown in fig. 3, the motor rotor shaft 1 is nested outside the input shaft 7 and is mounted on the bearing seat 3 through the roller bearing 2, the grounding ring 4 is fixedly connected to the metal bracket 5, and the metal bracket 5 is fixedly connected to the bearing seat 3 to form a current path. In the preferred embodiment, the metal bracket 5 is fixedly connected to the bearing housing 3 by bolts 53. In other embodiments, the metal bracket 5 may also be fixedly connected to the bearing seat 3 by a fixing method such as pin connection or key connection. In a preferred embodiment, the metal bracket 5 is provided with an axial limiting mechanism for limiting the axial position of the grounding ring 4 to prevent the grounding ring from rotating or moving due to vibration or friction, so as to avoid the grounding ring 4 from being stuck with the motor rotor shaft 1 to cause damage. In a further preferred embodiment, the axial stop mechanism comprises a snap ring 51 which is snap-fitted on the metal holder 5 and a radial annular boss 52 which is integral with the metal holder 5. When the grounding ring 4 is installed, the snap ring 51 is firstly taken out, the grounding ring 4 is placed from one side of the snap ring on the metal bracket 5 and is abutted against the radial annular boss 52, and then the snap ring 51 is installed, so that the positioning and installation of the grounding ring 4 can be completed. The limiting mechanism is simple in structure, convenient to replace and convenient to detach and maintain the grounding structure. In other embodiments, the limiting mechanism may also adopt other parts or structures with limiting function, such as a limiting screw or a limiting pin.

In a further preferred embodiment, a hollow interior 12 is provided in the motor rotor shaft 1, the hollow interior 12 being provided with a lubricating oil, which lubricating oil itself has the function of providing lubrication and cooling for the motor rotor shaft 1. Motor rotor shaft 1 is provided with lubricating oil runner 11, and 11 both ends of lubricating oil runner communicate hollow inner chamber 12 respectively and hold chamber 6, make the lubricating oil in the motor rotor shaft 1 can flow out to holding in the chamber 6 and for ground ring 4 and motor rotor shaft 1 provide surface lubrication to provide lubrication for ground structure under the prerequisite that does not change the original lubricating system of motor. In a preferred embodiment, the opening of the lubricating oil flow passage 11 in the accommodating cavity 6 is arranged at the mounting position of the grounding ring 4, including the area covered by the side wall of the grounding ring 4 or one axial end of the grounding ring 4, so that lubricating oil can be directly lubricated on the grounding ring 4 after entering the accommodating cavity 6, and the loss of the lubricating oil in the flowing process is reduced. In other embodiments, a separate lubricant oil path may be provided for the accommodating chamber 6, but the overall structure of the motor in such embodiments becomes more complicated, increasing the manufacturing cost.

In a preferred embodiment, the ground ring 4 is structured as shown in fig. 4a and 4b, and includes a carbon ring 41 and a conductive wear layer 42 covering the carbon ring. The conductive wear layer 42 is configured as a metal layer in some embodiments, and may be configured as a conductive composite layer such as a graphite-metal composite layer in other embodiments. The conductive wear-resistant layer 42 can protect the carbon ring 41, prolong the service life of the carbon ring, and can further improve the lubricity between the grounding ring 4 and the motor rotor shaft 1 by adopting a metal material with self-lubricating property. The fully-coated conductive wear-resistant layer 42 is firmly connected with the carbon ring 41, is not easy to fall off and has a long service life. In some embodiments, the conductive wear layer may also only cover the radially inner and outer surfaces of the carbon ring 41, thereby reducing the overall manufacturing cost of the conductive ring 4.

The above embodiments are intended to describe the present invention in further detail with reference to the accompanying drawings so that those skilled in the art can understand the technical idea of the present invention. Within the scope of the claims of the present invention, optimization or equivalent substitution of the related component structures, and combination of the embodiments in different embodiments without conflict between the structure and the principle all fall within the protection scope of the present invention.

Claims (11)

1. The utility model provides a motor shaft ground structure, includes motor rotor axle, motor casing and ground ring, its characterized in that, the motor rotor axle with be provided with between the motor casing and hold the chamber, it is used for fixed mounting to be provided with connecting portion in the chamber to hold ground ring, ground ring with the contact surface of motor rotor axle becomes relative slip and rotates so that form the electric current route between motor rotor axle, ground ring and the motor casing, it provides lubricating medium for to hold the intracavity ground ring with the contact surface face of motor rotor axle provides the lubrication.

2. The motor shaft grounding structure of claim 1, wherein the grounding ring includes a carbon ring and a conductive wear layer, the carbon ring being coated with the conductive wear layer on radially inner and outer surfaces thereof.

3. The motor shaft grounding structure of claim 2, wherein the conductive wear layer is configured as a metal layer.

4. The motor shaft ground structure of claim 2 or 3, wherein the conductive wear layer entirely covers the surface of the carbon ring.

5. The motor shaft grounding structure of claim 1, wherein the connecting portion is configured to be fixedly attached to a metal bracket within the receiving cavity.

6. The motor shaft grounding structure of claim 5, wherein the metal bracket includes an axial stop mechanism to axially stop the grounding ring.

7. The motor shaft grounding structure of claim 6, wherein the axial limiting mechanism includes a clamping ring clamped to the metal bracket and an annular boss protruding from a surface of the metal bracket.

8. The motor shaft grounding structure of any one of claims 5 to 7, wherein the metal bracket is fixedly connected to the accommodating cavity by bolts.

9. The motor shaft grounding structure of claim 1, wherein the lubricating medium is configured as a lubricating oil.

10. The motor shaft grounding structure of claim 9, wherein the motor rotor shaft is configured as a hollow shaft, a lubricant is provided in the motor rotor shaft, the motor rotor shaft is provided with a lubricant flow passage, and the accommodating chamber communicates with a shaft internal cavity of the motor rotor through the lubricant flow passage to allow the lubricant to flow into the accommodating chamber.

11. The motor shaft grounding structure of claim 10, wherein an opening of the lubricating oil flow passage in the housing cavity is provided at a mounting position of the grounding ring.

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