Shaft current grounding carbon brush assembly for automobile high-voltage driving motor

Abstract

The utility model discloses a shaft current grounding carbon brush assembly for an automobile high-voltage driving motor, which relates to the field of automobile high-voltage driving motors and driving assemblies and comprises a carbon brush body, a sleeve, a spring, a carbon brush holder and a carbon brush cover. The carbon brush holder is provided with a square groove inside the carbon brush holder, the carbon brush holder is provided with a carbon brush body, a position sensor pressing plate, a motor rotor shaft, a mounting bolt and a motor shell are arranged on the motor matched with the carbon brush holder, the carbon brush body comprises a carbon rod and a braid wire, the sleeve is sleeved on the braid wire, the spring is sleeved on the sleeve, and the carbon brush body, the sleeve and the spring are arranged in the square groove inside the carbon brush holder. After the carbon brush assembly and the motor are installed on the motor, the whole structure adopts a labyrinth type design, and the carbon brush assembly and the position sensor pressing plate form a semi-sealing state; a certain space is formed in the carbon brush cover cap and can be used for storing carbon powder, and the carbon powder can be conveniently blown into the powder storage space through air formed in the machining groove of the shaft head in the rotating process.

Description

Technical Field

[0001] The utility model relates to the field of vehicle high-voltage drive motors and drive assemblies, and particularly relates to a shaft current grounding carbon brush assembly for an automotive high-voltage drive motor. Background Technique

[0002] Modern new energy vehicle high-voltage drive motors are generally permanent magnet synchronous motors with specialized high-voltage control circuits. Based on the working principle of the control circuit, a certain shaft voltage will be generated between the rotating shaft of the motor and the motor housing (ground) during the operation of the motor. The shaft voltage will form a loop through the rotating shaft, bearing, motor housing, etc. and generate shaft current in the loop. The shaft current will cause irreversible damage to the bearing raceway, steel balls, etc., resulting in abnormal noise and premature failure of the bearing. Bearing failure caused by shaft current accounts for a relatively large proportion of current vehicle drive motors. Moreover, with the continuous increase of the motor voltage and speed, the shaft voltage is getting larger and larger, and more effective, reliable, and economical technical solutions are needed to solve this problem.

[0003] Currently, several mainstream shaft current technical solutions include carbon fiber rings (refer to the background patent "Slip Ring and Motor", application publication number: CN218386131U); conductive bearings (refer to the background patent "Motor Rotor, Motor and Vehicle", application publication number: CN112701824 A); and carbon brush / carbon rod structures (refer to the background patent "Carbon Brush Assembly for Shaft Current Grounding of Motor and Its Installation Structure", application publication number: CN11614191A). Comparing these methods in terms of cost, structural complexity, reliability, etc., the carbon brush / carbon rod structure has advantages in terms of cost, maintenance, reliability, etc., but there are still certain disadvantages:

[0004] 1. Currently, the carbon brush in the motor is exposed without protection, and carbon powder may be randomly distributed inside the motor, which will cause certain damage to the insulation components of the motor, and the carbon powder may accumulate on the surface of some bare copper parts, resulting in premature failure;

[0005] 2. Currently, the carbon brush structure has no carbon brush fixing structure. During installation, it is necessary to manually press the head of the carbon brush to place the carbon brush and the shaft in the relative installation position, and this process may cause premature damage to the head of the carbon brush, resulting in early failure. Content of the Utility Model

[0006] Based on this, the purpose of the present utility model is to provide a shaft current grounding carbon brush assembly for an automotive high-voltage drive motor, so as to solve the technical problems that the carbon brush is bare and unprotected inside the motor, the carbon powder may be randomly distributed inside the motor, which will cause certain damage to the insulation components of the motor, and the carbon powder may accumulate on the surface of some bare copper parts, resulting in premature failure. There is no carbon brush fixing structure, and when installing, it is necessary to manually press the head of the carbon brush to place the carbon brush and the shaft in the relative installation position, and this process may cause premature damage to the head of the carbon brush, resulting in early failure.

[0007] To achieve the above object, the present utility model provides the following technical solution: A shaft current grounding carbon brush assembly for an automotive high-voltage drive motor, including a carbon brush body, a sleeve, a spring, a carbon brush holder, and a carbon brush cover. At the same time, the components on the motor that cooperate with it are a position sensor, a position sensor pressure plate, a motor rotor shaft, mounting bolts, and a motor housing. The carbon brush body includes a carbon rod and a braided wire. The sleeve is sleeved on the braided wire, and the spring is sleeved on the sleeve. The carbon brush body, the sleeve, and the spring are placed in a square groove inside the carbon brush holder. The carbon brush holder contains a copper insert. The tail end of the braided wire is connected to the corresponding position of the copper insert. The carbon brush holder is connected to the motor housing through mounting bolts. One end of the carbon brush holder where the carbon rod is located is connected with a carbon brush cover. A perforation matching the carbon brush body is arranged inside the carbon brush cover. The carbon brush cover and the position sensor pressure plate together form a labyrinth seal structure and are fixed together by screws. The motor rotor shaft contacts the carbon brush body, and a circuit is formed through the carbon rod, the braided wire, the copper insert, the mounting bolts, and the motor housing to conduct the shaft current. A storage space is formed inside the carbon brush cover.

[0008] The present utility model is further set as that the carbon brush holder and the copper insert are integrally formed by injection molding.

[0009] The present utility model is further set as that the tail end of the braided wire is connected to the corresponding position on the copper insert by resistance welding or soldering and is sealed with structural adhesive.

[0010] The present utility model is further set as that one side of the carbon brush holder protrudes and is provided with an upper screw hole, and a lower screw hole corresponding to the upper screw hole is arranged on the motor housing, and mounting bolts are screwed into the upper screw hole and the lower screw hole.

[0011] The present utility model is further set as that a positioning post is fixed on the contact surface between the carbon brush holder and the motor housing, and a positioning hole matching the positioning post is arranged on the motor housing.

[0012] The present utility model is further set as that multiple groups of insertion slots are arranged on the outer side of one end of the carbon brush holder, and multiple groups of insertion posts matching the insertion slots are arranged on the inner side of the carbon brush cover.

[0013] The present utility model is further configured such that a limiting convex block is further provided on the outer side of one end of the carbon brush holder, and two sets of upper and lower limiting card slots for cooperating with the limiting convex block are provided on the inner side of the carbon brush cover.

[0014] The present utility model is further configured such that an interference fit connection is adopted between the carbon brush holder and the carbon brush cover.

[0015] In summary, the present utility model mainly has the following beneficial effects:

[0016] 1. The carbon brush assembly of the present utility model and the overall structure after installation on the motor adopt a labyrinth design. The carbon brush assembly and the position sensor pressure plate form a semi-sealed state; a certain space is provided inside the carbon brush cover for storing carbon powder, and the wind formed by the processing groove at the shaft head during rotation is convenient for blowing the carbon powder into the powder storage space.

[0017] 2. Before the carbon brush assembly of the present utility model is installed, the head of the carbon brush body is fixed in the brush box by the carbon brush cover. During installation, the operator does not need to contact the carbon brush body. Only after the assembly is installed, the carbon brush cover is pressed in place, and the carbon brush body will automatically pop out and contact the shaft, avoiding potential failure hazards caused by installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic installation structure diagram of the present utility model;

[0019] Figure 2 is of the present utility model Figure 1 is a schematic structure diagram after removing the carbon brush cover in the present utility model;

[0020] Figure 3 is a schematic mating structure diagram of installing the carbon brush body of the present utility model;

[0021] Figure 4 is an assembly drawing of the carbon brush body and the carbon brush holder of the present utility model;

[0022] Figure 5 is of the present utility model Figure 4 is another perspective view;

[0023] Figure 6 is a mating diagram of the carbon brush holder and the carbon brush cover of the present utility model;

[0024] Figure 7 is an installation drawing of the carbon brush body and the sleeve of the present utility model;

[0025] Figure 8 is a schematic structure diagram of the carbon brush cover of the present utility model;

[0026] Figure 9 is a schematic structure diagram of the carbon brush body of the present utility model;

[0027] Figure 10This is the state diagram of the carbon brush cover of the present utility model before installation;

[0028] Figure 11 This is the state diagram of the carbon brush cover of the present utility model after installation;

[0029] Figure 12 This is the carbon powder flow diagram inside the carbon brush cover of the present utility model.

[0030] In the figure: 1. Carbon brush body; 2. Sleeve; 3. Spring; 4. Carbon brush holder; 5. Copper insert; 6. Carbon brush cover; 7. Position sensor; 8. Position sensor pressure plate; 9. Motor rotor shaft; 10. Installation bolt; 11. Motor housing; 12. Carbon rod; 13. Braid wire; 14. Positioning hole; 15. Positioning post; 16. Lower screw hole; 17. Upper screw hole; 18. Insertion slot; 19. Perforation; 20. Insertion post; 21. Limit lug; 22. Limit card slot; 23. Storage space. Specific embodiments

[0031] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.

[0032] Next, according to the overall structure of the present utility model, its embodiments will be described.

[0033] An axial current grounding carbon brush assembly for an automotive high-voltage drive motor, as Figure 1-9 shown: It includes a carbon brush body 1, a sleeve 2, a spring 3, a carbon brush holder 4, and a carbon brush cover 6. At the same time, the components on the motor that cooperate with it are a position sensor 7, a position sensor pressure plate 8, a motor rotor shaft 9, an installation bolt 10, and a motor housing 11. The carbon brush body 1 includes a carbon rod 12 and a braid wire 13. The sleeve 2 is sleeved on the braid wire 13, and the spring 3 is sleeved on the sleeve 2. The carbon brush body 1, the sleeve 2, and the spring 3 are placed in a square groove inside the carbon brush holder 4. The carbon brush holder 4 contains a copper insert 5. The carbon brush holder 4 and the copper insert 5 are integrally formed by injection molding. The tail end of the braid wire 13 is connected to the corresponding position of the copper insert 5. The carbon brush holder 4 is connected to the motor housing 11 through an installation bolt 10. One side of the carbon brush holder 4 protrudes and is provided with an upper screw hole 17. The motor housing 11 is provided with a lower screw hole 16 corresponding to the upper screw hole 17. An installation bolt 10 is screwed into the upper screw hole 17 and the lower screw hole 16. One end of the carbon brush holder 4 where the carbon rod 12 is located is connected with a carbon brush cover 6. Multiple groups of insertion slots 18 are provided on the outer side of one end of the carbon brush holder 4. Multiple groups of insertion posts 20 that cooperate with the insertion slots 18 are provided on the inner side of the carbon brush cover 6. The carbon brush holder 4 and the carbon brush cover 6 are connected by interference fit. A perforation 19 that cooperates with the carbon brush body 1 is provided inside the carbon brush cover 6.

[0034] On the outer side of one end of the carbon brush holder 4, a limiting bump 21 is further provided. On the inner side of the carbon brush cover 6, there are two sets of upper and lower limiting card slots 22 that cooperate with the limiting bump 21. Before installing the carbon brush cover 6, as Figure 10 shown, first, the lower set of limiting card slots 22 is stuck on the limiting bump 21, and the carbon brush cover 6 is placed in the middle position of the carbon brush holder 4. The carbon rod 12 of the carbon brush body 1 is blocked by the structure on the carbon brush cover 6 and cannot pop out. At this time, the spring 3 is in a compressed state. During installation, the carbon brush cover 6 is manually pressed forcefully. By using the deformation of the material of the carbon brush cover 6 and the inclined surface structure on the upper side of the lower limiting card slot 22, the upper limiting card slot 22 is made to be stuck on the limiting bump 21 to complete the installation. As Figure 11 shown, after the installation is completed, the carbon brush cover 6 is placed at the bottom position, and the carbon rod 12 of the carbon brush body 1 can pop out through the through hole 19 under the action of the spring 3 resetting, and form a cooperation with the motor rotor shaft. During installation, the operator does not need to contact the carbon brush body 1. Only after the assembly is installed, the carbon brush cover 6 needs to be pressed in place, and the carbon brush body 1 will automatically pop out and contact the motor rotor shaft 9, avoiding the potential failure hidden danger caused by installation. The motor rotor shaft 9 contacts the carbon brush body 1, and through the carbon rod 12, the braided wire 13, the copper insert 5, and the mounting bolt 10, a circuit is formed with the motor housing 11 to conduct the shaft current.

[0035] The carbon brush cover 6 and the position sensor pressure plate 8 together form a labyrinth seal structure, which is fixed together by screws. The carbon brush assembly and the position sensor pressure plate 8 form a semi-sealed state.

[0036] A storage space 23 is formed on the inner side of the carbon brush cover 6. The wind formed by the machining groove at the head of the motor rotor shaft 9 during rotation can effectively blow the carbon powder into the space formed on the inner side of the carbon brush cover 6 for storage.

[0037] The tail end of the braided wire 13 and the corresponding position on the copper insert 5 are connected by resistance welding or soldering, and structural adhesive is used for sealing to ensure the structural strength and sealing performance here.

[0038] A positioning column 15 is fixed on the contact surface between the carbon brush holder 4 and the motor housing 11. A positioning hole 14 that cooperates with the positioning column 15 is provided on the motor housing 11. During installation, the positioning column 15 is inserted into the positioning hole 14 and cooperates with the mounting bolt 10, making the fixing effect of the carbon brush assembly more stable.

[0039] Although the embodiments of the present invention have been shown and described, the specific embodiments are only explanations of the present invention and are not limitations to the invention. The specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. After reading this specification, those skilled in the art can, without departing from the principles and purposes of the present invention, make modifications, substitutions, and variations that do not make creative contributions to the embodiments as needed, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. An axial current grounding carbon brush assembly for a high-voltage drive motor of an automobile, comprising a carbon brush body (1), a sleeve (2), a spring (3), a carbon brush holder (4), a carbon brush cover (6), and the components on the motor that cooperate with it include a position sensor (7), a position sensor pressure plate (8), a motor rotor shaft (9), mounting bolts (10), and a motor housing (11), characterized in that: The carbon brush body (1) includes a carbon rod (12) and a braided wire (13). The sleeve (2) is sleeved on the braided wire (13), and the spring (3) is sleeved on the sleeve (2). The carbon brush body (1), the sleeve (2), and the spring (3) are placed in a square groove inside the carbon brush holder (4). The carbon brush holder (4) contains a copper insert (5). The tail end of the braided wire (13) is connected to the corresponding position of the copper insert (5). The carbon brush holder (4) is connected to the motor housing (11) through a mounting bolt (10). A carbon brush cover (6) is connected to one end of the carbon rod (12) of the carbon brush holder (4). A perforation (19) that cooperates with the carbon brush body (1) is provided inside the carbon brush cover (6). The carbon brush cover (6) and the position sensor pressure plate (8) together form a labyrinth seal structure and are fixed together by screws. The motor rotor shaft (9) contacts the carbon brush body (1), and a circuit is formed through the carbon rod (12), the braided wire (13), the copper insert (5), the mounting bolt (10), and the motor housing (11) to conduct the shaft current. A storage space (23) is formed inside the carbon brush cover (6).

2. The shaft current grounding carbon brush assembly for an automotive high-voltage drive motor according to claim 1, characterized in that: The carbon brush holder (4) and the copper insert (5) are integrally formed by injection molding.

3. The shaft current grounding carbon brush assembly for an automotive high-voltage drive motor according to claim 1, characterized in that: The tail end of the braided wire (13) is connected to the corresponding position on the copper insert (5) by resistance welding or soldering and sealed with structural adhesive.

4. The shaft current grounding carbon brush assembly for a high-voltage drive motor of an automobile according to claim 1, characterized in that: One side of the carbon brush holder (4) protrudes and is provided with an upper screw hole (17). A lower screw hole (16) corresponding to the upper screw hole (17) is provided on the motor housing (11), and a mounting bolt (10) is screwed into the upper screw hole (17) and the lower screw hole (16).

5. The shaft current grounding carbon brush assembly for a high-voltage drive motor of an automobile according to claim 1, characterized in that: A positioning post (15) is fixed on the contact surface between the carbon brush holder (4) and the motor housing (11). A positioning hole (14) that cooperates with the positioning post (15) is provided on the motor housing (11).

6. The shaft current grounding carbon brush assembly for an automotive high-voltage drive motor according to claim 1, wherein: A plurality of plug-in grooves (18) are provided on the outer side of one end of the carbon brush holder (4). A plurality of plug-in posts (20) that cooperate with the plug-in grooves (18) are provided on the inner side of the carbon brush cover (6).

7. An axial current grounding carbon brush assembly for a high-voltage drive motor of an automobile according to claim 1, characterized in that: A limiting convex block (21) is further provided on the outer side of one end of the carbon brush holder (4). Two upper and lower limiting card slots (22) that cooperate with the limiting convex block (21) are provided on the inner side of the carbon brush cover (6).

8. The shaft current grounding carbon brush assembly for an automotive high-voltage drive motor according to claim 6 or 7, characterized in that: The carbon brush holder (4) and the carbon brush cover (6) are connected by interference fit.

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