Grounding carbon brush and position sensor combination assembly for automobile high-voltage driving motor

Abstract

The invention discloses a grounding carbon brush and position sensor combined assembly for an automobile high-voltage driving motor, which comprises a main shell, and is characterized in that the left end of the main shell is an external connector, a connector insert is arranged in the external connector, a plurality of bolt mounting holes are formed in the edge of the main shell, the bolt mounting holes in the left end and the right end of the main shell are connected with a brush holder, and the brush holder is fixedly connected with the main shell. A carbon brush assembly is arranged in the brush carrier, a circular groove is formed in the main shell, and a movable carbon brush protection plate is clamped in the circular groove. Certain electronic devices are arranged between the grounding carbon brush connecting shaft and the ground and used for reducing common-mode voltage on the shaft, and the devices and the eddy current sensor share one PCB. Before the carbon brush assembly is installed, the head of the carbon brush body is fixed in the brush box through the carbon brush protection plate, an operator does not need to make contact with the carbon brush body during installation, when the assembly is installed, a motor shell can press the carbon brush protection plate in place, the carbon brush body automatically pops out to make contact with a shaft, and the failure hidden danger caused by installation is avoided.

Description

Technical Field

[0001] The invention relates to the field of high-voltage drive motors and drive assemblies for vehicles, and in particular to a grounding carbon brush and position sensor combination assembly for high-voltage drive motors for vehicles. Background Art

[0002] Modern automotive new energy high-voltage drive motors are generally permanent magnet synchronous motors with special high-voltage control circuits. Based on the working principle of the control circuit, a certain shaft voltage will be generated on the motor shaft compared to the motor housing (ground) when the motor is working. The shaft voltage will form a circuit through the shaft, bearings, motor housing, etc. and generate shaft current in the circuit. The shaft current will cause irreversible damage to the bearing raceways, steel balls, etc., causing the bearings to produce abnormal noises and fail prematurely. Bearing failures caused by shaft currents account for a large proportion of current automotive drive motors. As the motor voltage and speed continue to increase, the shaft voltage becomes larger and larger. A more effective, reliable and economical technical solution is needed to solve this problem.

[0003] At present, the mainstream shaft current technology solutions include carbon fiber rings (refer to the background patent "Conductive ring and motor", application publication number: CN218386131U); sacrificial bearings (refer to the background patent "Motor rotor, motor and vehicle", application publication number: CN112701824 A); and carbon brush / carbon rod structure (refer to the background patent "Carbon brush assembly and mounting structure for motor shaft current grounding", application publication number: CN11614191A). Among these methods, the carbon brush / carbon rod structure has advantages in terms of cost, structural complexity, reliability, etc., but it still has certain disadvantages.

[0004] Based on the principle of motor control, modern automotive new energy high-voltage drive motors must be equipped with rotor angle position sensors for real-time monitoring of the relative angle relationship between the rotor poles and the stator coils. The mainstream position sensors currently used are generally rotary transformers, which are divided into coil parts, rotor parts and connector parts. Rotary transformers have relatively high installation requirements, complex structures, precise and easily damaged parts, and analog signals that need to be decoded and converted. Therefore, in recent years, a new type of position sensor that uses the eddy current principle to collect rotor position signals has emerged (reference background patent "An angular position sensor", application publication number CN113008130A). Compared with rotary transformers, this sensor has the advantages of high detection accuracy, small size and low cost, but compared with rotary transformers, there is no improvement in terms of installation method, degree of integration and other aspects. It still needs to be installed inside the motor, and it is more troublesome to use bolts to fasten. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide a grounding carbon brush and position sensor combination assembly for a high-voltage drive motor of an automobile to solve the problems mentioned in the above background technology.

[0006] The technical solution is as follows: A grounding carbon brush and position sensor combination assembly for a high-voltage driving motor of an automobile, comprising a main shell, characterized in that the left end of the main shell is an external connector, in which a connector insert is arranged, a plurality of bolt mounting holes are arranged on the edge of the main shell, and the bolt mounting holes on the left and right ends are connected to a brush holder, a carbon brush assembly is arranged in the brush holder, a circular groove is arranged in the main shell, a movable carbon brush guard plate is engaged in the circular groove, a PCB board is arranged on the main shell, a main control circuit, an internal connector, an eddy current coil, and a grounding device are arranged on the PCB board; the motor shaft can penetrate into the circular groove of the main shell to contact the carbon rod; the motor stator temperature sensor circuit can be exported to the outside of the motor through the internal connector, the main control circuit, and the external connector, thus forming a complete circuit transmission.

[0007] Furthermore, the main housing is connected to the motor, and a sealing strip is provided between the main housing and the motor bottom shell.

[0008] Furthermore, the sealing strip is bonded to the main shell body by using a process such as dispensing or liquid silicone, and surrounds the upper edge of the main shell body.

[0009] Furthermore, the carbon brush guard is composed of a carbon rod, a sleeve, a braided wire and a spring. The carbon rod and the braided wire are formed as one piece. The sleeve is sleeved on the braided wire, and the spring is sleeved on the sleeve.

[0010] Furthermore, the main housing is installed in a cavity sealing portion on the motor bottom shell, and a packaging cover is provided at the outer end of the main housing, which covers the internal components of the main housing.

[0011] In summary, the present invention mainly has the following beneficial effects:

[0012] 1. The assembly has both the shaft grounding carbon brush and the eddy current sensor, which are fully integrated and share key components (PCB board and main housing); the installation of the previous two components can be completed in one assembly;

[0013] 2. The assembly is installed outside the motor and has waterproof and dustproof properties. The assembly has a 4-pin connector facing the inside of the motor for connecting the temperature sensor on the stator coil. The assembly has a 10-14-pin connector facing the outside of the motor for connecting with the wiring harness of the motor controller. Therefore, the mechanism of penetrating the cylinder or merging the connectors is omitted, and the assembly has the function of exporting the wiring harness to the outside.

[0014] 3. Certain electronic devices are arranged between the grounding carbon brush connecting shaft and the ground to reduce the common mode voltage on the shaft. These devices share a PCB board with the eddy current sensor. Before the carbon brush assembly is installed, the head of the carbon brush body is fixed in the brush box by the carbon brush guard. The operator does not need to touch the carbon brush body during installation. When the assembly is installed, the motor housing will press the carbon brush guard into place, and the carbon brush body will automatically pop out and contact the shaft, avoiding the hidden danger of failure caused by installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0016] Figure 2 It is a schematic diagram of the shaft head structure of the present invention;

[0017] Figure 3 It is the internal structure diagram of the present invention;

[0018] Figure 4 It is a schematic diagram of the shell structure of the present invention;

[0019] Figure 5 This is a schematic diagram of the housing after the present invention is reversed;

[0020] Figure 6 It is a schematic diagram of the interior of the shell after being reversed according to the present invention.

[0021] In the figure: 1-main housing;

[0022] 2-External connector;

[0023] 3-Connector insert;

[0024] 4-Mounting holes;

[0025] 5-Brush holder;

[0026] 50-square slot;

[0027] 7-Carbon brush guard;

[0028] 8-PCB board;

[0029] 9- Main control circuit;

[0030] 10-internal connector;

[0031] 11- eddy current coil;

[0032] 12- grounding device;

[0033] 13- Sealing strip;

[0034] 14-Carbon rod;

[0035] 15- casing;

[0036] 16- braided wire;

[0037] 17- Spring;

[0038] 100-packaging cover;

[0039] 101-Axle head. DETAILED DESCRIPTION

[0040] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0041] The following describes an embodiment of the present invention based on its overall structure.

[0042] See also Figure 1-6 A grounding carbon brush and position sensor combination assembly for a high-voltage driving motor of an automobile comprises a main shell 1, the left end of the main shell 1 is an external connector 2, in which a connector insert 3 is arranged, a plurality of bolt mounting holes 4 are arranged on the edge of the main shell 1, and the bolt mounting holes 4 at the left and right ends thereof are connected to a brush holder 5, in which a carbon brush assembly is arranged, a carbon brush guard plate 7 is placed in the middle position before installation, and the carbon brush body is blocked by the structure on the carbon brush guard plate 7 and cannot be ejected; after the installation is completed, the carbon brush guard plate 7 is lifted up by the corresponding structure in the shell and placed in the top position, and the carbon brush body can be ejected, a circular groove is arranged in the main shell 1, and a movable carbon brush guard plate 7 is engaged in the circular groove, a PCB board 8 is arranged on the main shell 1, and the PCB board 8 can be embedded in the main shell 1, and a main control circuit 9, an internal connector 10, an eddy current coil 11, and a grounding device 12 are arranged on the PCB board 8.

[0043] Furthermore, the main housing 1 is connected to the motor, and a sealing strip 13 is provided between the main housing 1 and the motor bottom shell. The sealing strip 13 is bonded to the main housing 1 by dispensing or liquid silicone and surrounds the upper edge of the main housing 1.

[0044] Furthermore, the carbon brush guard plate 7 is composed of a carbon rod 14, a sleeve 15, a braid wire 16, and a spring 17. The carbon rod 14 and the braid wire 16 are formed as one piece. The sleeve 15 is sleeved on the braid wire 16, and the spring 17 is sleeved on the sleeve 15. The carbon brush assembly should be placed in the corresponding square groove 50 on the main housing 1. The tail end of the carbon brush braid wire 16 is connected to the corresponding hole position on the carbon brush insert by resistance welding or soldering. The welding part is installed with a carbon brush cover and filled with structural adhesive for protection; at the same time, the carbon brush cover is sealed and assembled with the main housing 1. The control circuit should be placed in the corresponding position of the main housing 1, and the hole position on it cooperates with the pin position on the connector insert 3 and the carbon brush insert and the ground insert and is connected by soldering. After welding, the control PCB board 8 is The entire surface should be completely covered and packaged with epoxy resin or other types of colloids, which is more secure. The motor shaft can penetrate into the circular groove of the main housing 1 and contact the carbon rod 14. The motor shaft contacts the carbon brush carbon rod 14, and a loop is formed with the carbon rod 14, the braided wire 16, the carbon brush insert, the grounding device 12, the grounding insert and the motor housing to reduce the shaft voltage and conduct the shaft current; the motor shaft head 101 should be processed or installed with a corresponding induced structure for the rotor pole structure, which is used to form a position sensor together with the eddy current coil 11; the internal connector is used to connect the motor temperature sensor, etc., and the above is transmitted to the motor controller together by the control PCB board 8, the connector insert 3, and the external connector 2.

[0045] The main housing 1 is installed in the cavity sealing part on the motor bottom shell. The outer end of the main housing 1 is provided with a packaging cover 100, which covers the internal components of the main housing 1. After the carbon brush assembly, carbon brush guard plate 7, eddy current PCBA and other components are assembled and tested, they are welded together with the brush holder 5 using ultrasonic welding technology, which belongs to the final packaging.

[0046] The shaft head 101 is sealed in a cavity, and the entire sensor is in contact with the shaft head 101 through bolts and is installed in the sealed cavity around the shaft head 101 .

[0047] Although an embodiment of the present invention has been shown and described, this specific embodiment is merely an explanation of the present invention and is not a limitation of the invention. The specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions and variations to the embodiments without creative contributions as needed without departing from the principles and purpose of the present invention. However, as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A grounding carbon brush and position sensor assembly for a high-voltage drive motor of an automobile, comprising a main housing (1), characterized in that: The left end of the main housing (1) is an external connector (2), which is provided with a connector insert (3). The edge of the main housing (1) is provided with a plurality of bolt mounting holes (4). The bolt mounting holes (4) at the left and right ends are connected to a brush holder (5). The brush holder (5) is provided with a carbon brush assembly. A circular groove is provided in the main housing (1), a movable carbon brush guard plate (7) is clamped in the circular groove, a PCB board (8) is provided on the main housing (1), and a main control circuit (9), an internal connector (10), an eddy current coil (11), and a grounding device (12) are provided on the PCB board (8). The motor shaft can penetrate into the circular groove of the main housing (1) and contact the carbon rod (14); the motor stator temperature sensor circuit can be led out to the outside of the motor through the internal connector (10), the main control circuit (9) and the external connector (2).

2. The grounding carbon brush and position sensor assembly for a high-voltage drive motor of an automobile according to claim 1, characterized in that: The main housing (1) is connected to the motor, and a sealing strip (13) is provided between the main housing (1) and the motor bottom shell.

3. The grounding carbon brush and position sensor assembly for a high-voltage drive motor of an automobile according to claim 2, characterized in that: The sealing strip (13) is bonded to the main housing (1) by using a process such as dispensing glue or liquid silicone and surrounds the upper edge of the main housing (1).

4. The grounding carbon brush and position sensor assembly for a high-voltage driving motor of an automobile according to claim 1, characterized in that: The carbon brush guard plate (7) is composed of a carbon rod (14), a sleeve (15), a braid wire (16), and a spring (17). The carbon rod (14) and the braid wire (16) are integrally formed. The sleeve (15) is sleeved on the braid wire (16), and the spring (17) is sleeved on the sleeve (15).

5. The grounding carbon brush and position sensor assembly for a high-voltage driving motor of an automobile according to claim 1, characterized in that: The main housing (1) is installed in a cavity sealing portion on a motor bottom shell, and a packaging cover (100) is provided at the outer end of the main housing (1), and the packaging cover (100) covers the internal components of the main housing (1).

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