A carrier ring for a combined electrically conductive ring

Abstract

The utility model provides a kind of load ring of combined conductive ring, including combined conductive ring, combined conductive ring includes middle support spring, the both sides of middle support spring are equipped with conductive sheet, the outside of combined conductive ring is equipped with inner ring, the center of inner ring is equipped with inner hole, inner hole is used to be connected on motor shaft, conductive ring is arranged in positioning groove, and the side wall of conductive sheet is resisted with positioning groove, the scheme will the way that original combined conductive ring needs to be slotted on motor shaft is changed into load ring installation, it is convenient for party B to unify the specification of motor shaft, the installation adaptability of conductive ring is improved, the problem that the conductive ring of original design needs to be slotted on motor shaft is solved, and combined conductive ring is not convenient to disassemble and assemble.

Description

Technical Field

[0001] This utility model relates to the field of motor grounding, and in particular to a bearing ring for a combined conductive ring. Background Technology

[0002] In electric vehicle (EV) drive systems, permanent magnet synchronous motors achieve precise control through variable frequency drives (VFDs) in the motor controller (MCU). The core technology is pulse width modulation (PWM)—using high-frequency switching devices (such as IGBTs) to convert the direct current from the battery into alternating current with adjustable frequency and voltage. While this process meets the vehicle's power requirements, it has inherent technical limitations: PWM modulation generates common-mode voltage due to three-phase voltage asymmetry. This voltage couples through the parasitic capacitance between the stator windings and the rotor, forming a shaft voltage between the motor shaft and the housing.

[0003] When the shaft voltage accumulates to a level exceeding the breakdown threshold of the bearing grease, discharge occurs at the contact points between the rolling elements and the inner and outer rings, triggering an electrical discharge machining (EDM) effect. This results in pits, electro-corrosion spots, and grooves forming on the bearing surface. Such damage deteriorates rapidly under EV operating conditions (high-frequency start-stop, high-speed fluctuations), directly causing abnormal motor noise, increased vibration, and even sudden shutdown, seriously affecting driving safety and significantly increasing maintenance costs.

[0004] To prevent the aforementioned damage paths, EV drive motors using VFD or DC drivers must be equipped with bearing protection devices. Our company's Chinese patent CN120033919A discloses a "combined conductive ring" that solves this problem by establishing a shaft voltage release path. Its core principle is that the shaft voltage generated when the motor shaft rotates is conducted to the motor housing through a conductive sheet for safe release, preventing current from flowing through the bearing and forming a discharge path.

[0005] This solution further optimizes the design by changing the original method of mounting the combined conductive ring on the motor shaft through slots to a load-bearing ring. This makes it easier for the contractor to standardize the specifications of the motor shaft. Its function remains the same: the shaft voltage generated when the motor shaft rotates is transmitted to the motor housing through the conductive sheet, thereby completing the release of the shaft voltage. Utility Model Content

[0006] The main purpose of this utility model is to provide a carrier ring for a combined conductive ring, which solves the problem that the original conductive ring design requires a slot to be opened on the motor shaft, and the combined conductive ring is not easy to disassemble and assemble.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a carrier ring for a combined conductive ring, including a combined conductive ring, the combined conductive ring including a middle support spring, conductive plates provided on both sides of the middle support spring, an inner ring provided on the outer side of the combined conductive ring, an inner hole provided at the center of the inner ring, the inner hole being used to fit onto the motor shaft, and the conductive ring being arranged in a positioning groove. The conductive sheet abuts against the side wall of the positioning groove.

[0008] In the preferred embodiment, the side of the positioning groove that abuts against the conductive sheet is provided with a wear-resistant coating, and the side of the positioning groove that abuts against the conductive sheet is provided with a Me-DLC coating. The inner ring is made of CuSn8 bronze.

[0009] In the preferred embodiment, the wear-resistant coating is a W-DLC coating.

[0010] In the preferred embodiment, the thickness of the wear-resistant coating is 1-3 μm.

[0011] In the preferred embodiment, the inner ring is made of graphite copper.

[0012] In the preferred embodiment, the conductive sheet is made of SUS440C material.

[0013] In the preferred embodiment, the combined conductive ring and the inner ring are arranged coaxially.

[0014] This utility model provides a carrier ring for a combined conductive ring, which has the following beneficial effects: 1. This solution changes the original method of mounting the combined conductive ring by slotting it on the motor shaft to mounting it as a load-bearing ring, which makes it easier for the supplier to standardize the specifications of the motor shaft and improves the installation compatibility of the conductive ring.

[0015] 2. The combined conductive ring utilizes the coordinated work of the intermediate support spring, conductive sheet and motor housing to effectively conduct the shaft voltage generated when the motor shaft rotates to the outside of the motor, avoiding the discharge of shaft voltage on the motor bearing. This prevents unexpected motor shutdown caused by electrical discharge machining (EDM) pits, electro-corrosion spots and groove damage, greatly reduces maintenance costs, significantly extends the service life of motor bearings, and ensures stable operation of the motor. Attached Figure Description The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the installation of the bearing ring of this utility model; Figure 2 This is a partially enlarged view of the bearing ring of this utility model; Figure 3 This is an axonometric view of the bearing ring of this utility model; Figure 4 This is a cross-sectional view of the bearing ring of this utility model; Figure 5 This is a cross-sectional view of the bearing ring of this utility model after the conductive ring is loaded; Figure 6 This is an isometric view of the bearing ring of this utility model after the conductive ring is loaded.

[0016] In the figure: 2. Conductive sheet; 3. Motor shaft; 4. Motor housing; 5. Ground wire; 6. Combined conductive ring; 7. Inner ring; 701. Inner hole; 704. Positioning groove; 8. Conductive material; 9. Wear-resistant coating. Detailed Implementation

[0017] Example 1 Chinese patent CN120033919A proposes a combined conductive ring and its usage method. This solution further optimizes the design based on this, changing the original method of installing the combined conductive ring by slotting it on the motor shaft 3 to installing it as a bearing ring. This makes it easier for the supplier to standardize the specifications of the motor shaft 3. Its function is still that the shaft voltage generated when the motor shaft 3 rotates is transmitted to the motor housing 4 through the conductive sheet 2, and the shaft voltage is released by the ground wire 5.

[0018] like Figure 1-5 As shown, a carrier ring of a combined conductive ring includes a combined conductive ring 6. The combined conductive ring 6 includes a central support spring 1. Conductive plates 2 are provided on both sides of the central support spring 1. An inner ring 7 is provided on the outer side of the combined conductive ring 6. An inner hole 701 is provided at the center of the inner ring 7. The inner hole 701 is used to fit onto the motor shaft 3. The conductive ring 6 is arranged in a positioning groove 704. The conductive sheet 2 abuts against the side wall of the positioning groove 704.

[0019] In the preferred embodiment, the side of the positioning groove 704 that abuts against the conductive sheet 2 is provided with a wear-resistant coating 9, and the side of the positioning groove 704 that abuts against the conductive sheet 2 is also provided with a Me-DLC coating. The inner ring 7 is made of CuSn8 bronze.

[0020] In the preferred embodiment, the wear-resistant coating 9 is a W-DLC coating, and the Me-DLC coating can also be a Ti-DLC coating or a Cr-DLC coating.

[0021] In the preferred embodiment, the thickness of the wear-resistant coating 9 is 2-3 μm.

[0022] In the preferred embodiment, the inner ring 7 is made of graphite copper.

[0023] In the preferred embodiment, the conductive sheet 2 is made of alloy tool steel.

[0024] In the preferred embodiment, the combined conductive ring 6 and the inner ring 7 are arranged coaxially.

[0025] Example 2 Further explanation in conjunction with Example 1, such as Figure 1-5The structure shown in Chinese patent CN120033919A uses a highly wear-resistant material, PEEK resin, as the loss material for the conductive sheet 2. In the preferred embodiment of this solution, the conductive sheet 2 is made of alloy tool steel and is a ring-shaped thin sheet. The processing difficulty of alloy tool steel is much lower than that of high wear-resistant material - PEEK resin material, thus improving the manufacturing efficiency and continuous production stability of the conductive sheet 2.

[0026] Example 3 like Figure 4 As shown in Example 2, in the preferred embodiment, the inner ring 7 is made of CuSn8 bronze. The side of the inner ring 7 made of CuSn8 bronze that is attached to the conductive sheet 2 is also provided with a W-DLC coating. When CuSn8 bronze is used as the inner ring, the friction surface must be treated with a W-DLC coating.

[0027] The W-DLC coating has a friction coefficient of 0.08 to 0.15, resulting in reduced heat generation, and optimized processing has no impact on performance; The dynamic total resistance of CuSn8 bronze with W-DLC coating is less than 0.3Ω. Its wear resistance life depends on the W-DLC coating and can reach less than 1μm / 30wkm. Without the W-DLC coating, the wear resistance design standard cannot be met. The precision requirements of non-friction surfaces are relaxed during the manufacturing process. The coating only needs to meet the film formation requirements on both sides of the positioning groove 704.

[0028] Example 4 like Figure 4 As shown, in the preferred embodiment, the inner ring 7 is made of graphite copper. When the inner ring 7 is made of graphite copper, no special treatment is required on its friction surface to achieve the wear resistance requirement. The friction coefficient is 0.4 to 0.5, the heat generation is ≤130℃, and the resistance of the graphite copper substrate is <0.002Ω. There is no need to improve the performance through coating. Graphite copper can achieve a thickness of 0.002-0.015μm / 30wkm without the need for coating, and the cost of the entire manufacturing process is controllable.

[0029] The above embodiments are merely preferred technical solutions of this utility model and should not be considered as limitations on this utility model. The protection scope of this utility model should be the technical solution described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the protection scope of this utility model.

Claims

1. A carrier ring for a combined conductive ring, comprising a combined conductive ring (6), the combined conductive ring (6) comprising a central support spring (1), and conductive sheets (2) provided on both sides of the central support spring (1), characterized in that: The outer side of the combined conductive ring (6) is provided with an inner ring (7), and the center of the inner ring (7) is provided with an inner hole (701). The inner hole (701) is used to fit onto the motor shaft (3). The combined conductive ring (6) is arranged in the positioning groove (704). The conductive sheet (2) abuts against the side wall of the positioning groove (704).

2. The carrier ring of the combined conductive ring according to claim 1, characterized in that: The side of the positioning groove (704) that abuts against the conductive sheet (2) is provided with a wear-resistant coating (9), and the side of the positioning groove (704) that abuts against the conductive sheet (2) is also provided with a Me-DLC coating; The inner ring (7) is made of CuSn8 bronze.

3. The bearing ring of the combined conductive ring according to claim 2, characterized in that: The wear-resistant coating (9) is a W-DLC coating.

4. The bearing ring of the combined conductive ring according to claim 2, characterized in that: The thickness of the wear-resistant coating (9) is 2-3 μm.

5. The bearing ring of the combined conductive ring according to claim 1, characterized in that: The inner ring (7) is made of graphite copper.

6. The bearing ring of the combined conductive ring according to claim 1, characterized in that: The conductive sheet (2) is made of SUS440C material.

7. The bearing ring of the combined conductive ring according to claim 1, characterized in that: The combined conductive ring (6) and the inner ring (7) are arranged coaxially.

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