Direct current motor
By using the torsion spring-driven carbon brushes in the DC motor in close contact with the commutator and setting damping strips on the connecting arm, the carbon brush fitting pressure reduction and noise problems are solved, and the normal operation and stability of the motor are improved.
Patent Information
- Application Number
- CN202421868230.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-02
- Publication Date
- 2025-06-13
- Estimated Expiration
- 2034-08-02
AI Technical Summary
In existing DC motors, the bonding pressure between the carbon brush and the commutator decreases with the increase in the number of times of use, resulting in poor bonding effect and affecting the normal use of the motor. At the same time, the bounce process between the carbon brush and the commutator causes metal resonance sound, causing unstable current and speed.
The first carbon brush and the second carbon brush are respectively used to maintain contact with the commutator on the rotor assembly under the action of the first torsion spring and the second torsion spring, and a damping strip is provided on the connecting arm to reduce the bounce process and ensure the continuous pressure and stable contact of the carbon brush to the commutator.
By maintaining the sufficient pressure on the commutator by the carbon brush, ensure the motor is running properly and eliminate metal resonance sounds by reducing the bounce process, improving the motor's operating stability and noise level.
Smart Images
Figure CN222981336U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of motors, in particular to a DC motor. Background Art
[0002] A DC motor is a motor that converts DC electrical energy into mechanical energy. According to different ways of generating magnetic fields, DC motors can be divided into permanent magnet type, excitation type (including shunt excitation, series excitation, compound excitation), etc. In practical applications, DC motors have the characteristics of large starting torque, wide speed regulation range, simple control, etc., and are widely used in various industrial, commercial and household equipment, such as power tools, fans, elevators, automotive starting motors, etc.
[0003] As the motor runs, the carbon brushes of the motor will experience wear, and the carbon brushes must be attached to the commutator. Therefore, an elastic device is needed to press the carbon brushes. The existing technology mainly sets a spiral spring in the installation groove of the carbon brush holder to make the carbon brushes fit the commutator. As the number of motor uses increases, the acting force of the spring becomes smaller and smaller, resulting in insufficient pressure, poor effect of the carbon brushes fitting the commutator, and affecting the normal use of the motor. In addition, when the motor runs, there is a bouncing process between the carbon brushes and the commutator segment grooves, resulting in the connecting arms between the carbon brushes and the connecting terminals bouncing accordingly, generating a metal resonance sound, and further causing unstable current and speed.
[0004] Therefore, the existing technology needs to be improved. Summary of the Utility Model
[0005] The purpose of the utility model is to provide a DC motor that can keep sufficient pressure on the commutator by the carbon brushes and has low noise for the deficiencies existing in the prior art.
[0006] To achieve the above purpose, the technical solution adopted by the utility model is:
[0007] A DC motor includes a housing, an end cover covering the opening of the housing, a rotor assembly disposed in the housing, and a stator surrounding the outer periphery of the rotor body of the rotor assembly.
[0008] A first carbon brush holder, a second carbon brush holder, a first wiring terminal and a second wiring terminal are provided on the end cover. The first carbon brush holder is disposed opposite to the second wiring terminal, and the second carbon brush holder is disposed opposite to the first wiring terminal.
[0009] A first carbon brush is slidably installed in the first carbon brush holder, and the first carbon brush remains in contact with the commutator on the rotor assembly under the action of the first movable terminal of the first torsion spring.
[0010] A second carbon brush is slidably installed in the second carbon brush holder, and the second carbon brush is kept in contact with the commutator on the rotor assembly under the action of the second movable terminal of the second torsion spring;
[0011] A first connecting arm is arranged between the first carbon brush and the first wiring terminal, a second connecting arm is arranged between the second carbon brush and the second wiring terminal, a first damping strip is arranged on one side of the first connecting arm facing the second connecting arm, and a second damping strip is arranged on one side of the second connecting arm facing the first connecting arm.
[0012] As a further solution of the present utility model, the rotor assembly includes a rotating shaft, a rotor body sleeved on the rotating shaft, a commutator, and a rotor winding wound on the rotor body and electrically connected to the commutator. Among them, the commutator is located on one side of the rotor body close to the opening of the housing.
[0013] As a further solution of the present utility model, the rotor body has six equally divided rotor chip teeth, and a winding groove is formed between two adjacent rotor chip teeth.
[0014] As a further solution of the present utility model, the first carbon brush holder and the second carbon brush holder are arranged adjacent to each other. A first positioning post is arranged on one side of the first carbon brush holder located on the second carbon brush holder, the first torsion spring is sleeved on the first positioning post, a second positioning post is arranged on one side of the second carbon brush holder located on the first carbon brush holder, the second torsion spring is sleeved on the second positioning post, a positioning base is arranged between the first positioning post and the second positioning post, and the first fixed terminal of the first torsion spring and the second fixed terminal of the second torsion spring are both located in the card slots of the positioning base.
[0015] As a further solution of the present utility model, a first notch for avoiding the first movable terminal of the first torsion spring is arranged on the first carbon brush holder, and a second notch for avoiding the second movable terminal of the second torsion spring is arranged on the second carbon brush holder.
[0016] As a further solution of the present utility model, a boss is arranged between the first wiring terminal and the second wiring terminal. A first groove for installing and connecting the first connecting wire of the first wiring terminal and a second groove for installing and connecting the second connecting wire of the second wiring terminal are arranged on the boss.
[0017] As a further solution of the present utility model, four heat dissipation ventilation holes are evenly distributed on the peripheral wall of the housing along the axial direction from near the end cover to near the rotor body.
[0018] Compared with the prior art, the beneficial effects of the present utility model are:
[0019] Due to the above structural design, that is, the first carbon brush and the second carbon brush are respectively kept in contact with the commutator on the rotor assembly under the action of the first torsion spring and the second torsion spring, so that the first carbon brush and the second carbon brush maintain sufficient and continuous pressure on the commutator, making the carbon brushes always closely adhere to the commutator, ensuring the normal use of the motor; and first damping strips and second damping strips are respectively arranged on the first connecting arm and the second connecting arm, reducing the bounce of the first connecting arm and the second connecting arm, thereby achieving the disappearance of metal resonance sound, reducing noise, and ensuring the stability of the current and speed during the operation of the motor. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG Figure 1 is a side view of an embodiment of the present utility model;
[0021] FIG Figure 2 is a sectional view of an embodiment of the present utility model;
[0022] FIG Figure 3 is a schematic diagram of the installation of the end carbon brush connection terminal and the connecting arm of an embodiment of the present utility model;
[0023] FIG Figure 4 is a schematic structural diagram of an end cover of an embodiment of the present utility model;
[0024] FIG Figure 5 is a top view of a rotor body of an embodiment of the present utility model;
[0025] In the figures:
[0026] 100 - housing, 200 - end cover, 300 - stator
[0027] 201 - first carbon brush holder, 202 - second carbon brush holder, 203 - first wiring terminal, 204 - second wiring terminal, 205 - first carbon brush, 206 - second carbon brush, 207 - first torsion spring, 208 - second torsion spring, 209 - first connecting arm, 210 - second connecting arm, 211 - first damping strip, 212 - second damping strip, 213 - first positioning post, 214 - second positioning post, 215 - positioning base, 216 - boss, 217 - first groove, 218 - second groove;
[0028] 2011 - first notch;
[0029] 2021 - second notch;
[0030] 2071 - first movable terminal, 2072 - first fixed terminal;
[0031] 2081 - second movable terminal, 2082 - second fixed terminal;
[0032] 401 - rotor shaft, 402 - rotor body, 403 - commutator;
[0033] 4021 - Rotor chip teeth, 4022 - Winding slot;
[0034] 101 - Heat dissipation ventilation hole. Detailed implementation manners
[0035] This part will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the drawings. The role of the drawings is to supplement the description in the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present utility model. However, it should not be construed as a limitation on the protection scope of the present utility model.
[0036] In the description of the present utility model, it should be understood that for the orientation description, such as the upper, lower, front, rear, left, right, etc., the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the present utility model.
[0037] In the description of the present utility model, the meaning of "several" is one or more, the meaning of "multiple" is two or more. Understand "greater than", "less than", "exceeding", etc. as not including the number itself, and "above", "below", "within", etc. as including the number itself. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.
[0038] In the description of the present utility model, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in the present utility model in combination with the specific content of the technical solution.
[0039] Embodiment:
[0040] Please refer to Figures 1-5, a DC motor of the present application includes a housing 100, an end cover 200 covering the opening of the housing 100, a rotor assembly disposed within the housing 100, and a stator 300 surrounding the periphery of the rotor body 402 of the rotor assembly. A first carbon brush holder 201, a second carbon brush holder 202, a first terminal 203, and a second terminal 204 are provided on the end cover 200. The first carbon brush holder 201 is disposed opposite to the second terminal 204, and the second carbon brush holder 202 is disposed opposite to the first terminal 203. A first carbon brush 205 is slidably installed within the first carbon brush holder 201, and the first carbon brush 205 remains in contact with the commutator 403 on the rotor assembly under the action of the first movable terminal 2071 of the first torsion spring 207. A second carbon brush 206 is slidably installed within the second carbon brush holder 202, and the second carbon brush 206 remains in contact with the commutator 403 on the rotor assembly under the action of the second movable terminal 2081 of the second torsion spring 208. Through the above structural design, as the number of uses of the first carbon brush 205 and the second carbon brush 206 increases, the first carbon brush 205 remains in contact with the commutator 403 on the rotor assembly under the action of the movable terminal 2071 of the first torsion spring 207, and the second carbon brush 206 remains in contact with the commutator 403 of the rotor assembly under the action of the movable terminal 2081 of the second torsion spring 208. Since the first movable terminal 2071 of the first torsion spring 207 and the second movable terminal 2081 of the second torsion spring 208 respectively press against the first carbon brush 205 and the second carbon brush 206, the first torsion spring 207 and the second torsion spring 208 respectively maintain sufficient and continuous pressure on the first carbon brush 205 and the second carbon brush 206, thereby enabling the first carbon brush 205 and the second carbon brush 206 to always closely adhere to the commutator 21, ensuring the normal operation of the motor.
[0041] A first connecting arm 209 is provided between the first carbon brush 205 and the first terminal 203, and a second connecting arm 210 is provided between the second carbon brush 206 and the second terminal 204. A first damping strip 211 is provided on the side of the first connecting arm 209 facing the second connecting arm 210, and a second damping strip 212 is provided on the side of the second connecting arm 210 facing the first connecting arm 209. By providing the first damping strip 211 and the second damping strip 212 on the first connecting arm 209 and the second connecting arm 210 respectively, the bounce of the first connecting arm 209 and the second connecting arm 210 is reduced, thereby achieving the disappearance of the metal resonance sound, reducing the noise, and ensuring the stability of the current and speed during the operation of the motor.
[0042] Specifically, the stator 300 is a permanent magnet. When magnetizing the permanent magnet, it is processed into a cross arrangement of two pairs of magnetic poles, that is, the center position of an S pole or an N pole is every 90°, and the S pole and the N pole are alternately arranged; the rotor assembly includes a rotating shaft 401, a rotor body 402 sleeved on the rotating shaft 401, a commutator 403, and a rotor winding (not shown in the figure) wound on the rotor body 402 and electrically connected to the commutator. Among them, the commutator 403 is located on the side of the rotor body 402 close to the opening of the housing 100; the rotor body 402 has six equally divided rotor chip teeth 4021, and a winding groove 4022 is formed between two adjacent rotor chip teeth 4021.
[0043] Specifically, the first carbon brush holder 201 and the second carbon brush holder 202 are arranged adjacent to each other. The first carbon brush holder 201 is provided with a first positioning post 213 on one side of the second carbon brush holder 202. The first torsion spring 207 is sleeved on the first positioning post 213. The second carbon brush holder 202 is provided with a second positioning post 214 on one side of the first carbon brush holder 201. The second torsion spring 208 is sleeved on the second positioning post 214. A positioning base 215 is arranged between the first positioning post 213 and the second positioning post 214. The first fixed terminal 2072 of the first torsion spring 207 and the second fixed terminal 2082 of the second torsion spring 208 are both located in the card slot (not shown in the figure) of the positioning base 215.
[0044] Specifically, the first carbon brush holder 201 is provided with a first notch 2011 for avoiding the first movable terminal 2071 of the first torsion spring 207. The second carbon brush holder 202 is provided with a second notch 2021 for avoiding the second movable terminal 2081 of the second torsion spring 208. Therefore, as the first carbon brush 205 and the second carbon brush 206 are continuously worn, the first movable terminal 2071 of the first torsion spring 207 can pass through the first notch 2011 to press the first carbon brush 205, and the second movable terminal 2081 of the second torsion spring 208 can pass through the second notch 2021 to press the second carbon brush 206.
[0045] Specifically, a boss 216 is arranged between the first wiring terminal 203 and the second wiring terminal 204. The boss 216 is provided with a first groove 217 for installing and connecting the first connecting wire of the first wiring terminal 203 and a second groove 218 for installing and connecting the second connecting wire of the second wiring terminal 204.
[0046] Specifically, the housing 100 is evenly provided with four heat dissipation ventilation holes 101 on the circumferential wall along the axial direction from near the end cover 200 to near the rotor body 402. Since the four heat dissipation ventilation holes are relatively large, the temperature rise of the motor is improved and the service life of the motor is extended.
[0047] In summary, through the above structural design, the utility model solves the deficiencies in the prior art and has the characteristics of reasonable structure, low noise, long service life, etc.
[0048] The above is only the specific implementation manner of the utility model, but the protection scope of the utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the utility model can easily think of changes or substitutions, which should all be covered within the protection scope of the utility model. Therefore, the protection scope of the utility model should be subject to the protection scope of the claims.
Claims
1. A DC motor, comprising a housing (100), an end cover (200) covering an opening of the housing (100), a rotor assembly arranged in the housing (100), and a stator (300) arranged around the outer periphery of a rotor body (402) of the rotor assembly, wherein the end cover (200) is provided with a first carbon brush holder (201), a second carbon brush holder (202), a first connecting terminal (203) and a second connecting terminal (204), the first carbon brush holder (201) and the second connecting terminal (204) being arranged opposite to each other, and the second carbon brush holder (202) and the first connecting terminal (203) being arranged opposite to each other, characterized in that: A first carbon brush (205) is slidably mounted in the first carbon brush holder (201), and the first carbon brush (205) maintains contact with the commutator (403) on the rotor assembly under the action of the first movable terminal (2071) of the first torsion spring (207); A second carbon brush (206) is slidably mounted in the second carbon brush holder (202), and the second carbon brush (206) maintains contact with the commutator (403) on the rotor assembly under the action of the second movable terminal (2081) of the second torsion spring (208); A first connecting arm (209) is provided between the first carbon brush (205) and the first connecting terminal (203), a second connecting arm (210) is provided between the second carbon brush (206) and the second connecting terminal (204), a first damping strip (211) is provided on a side of the first connecting arm (209) facing the second connecting arm (210), and a second damping strip (212) is provided on a side of the second connecting arm (210) facing the first connecting arm (209).
2. The DC motor according to claim 1, characterized in that: The rotor assembly comprises a rotating shaft (401), a rotor body (402) sleeved on the rotating shaft (401), a commutator (403), and a rotor winding wound on the rotor body (402) and electrically connected to the commutator (403), wherein the commutator (403) is located on a side of the rotor body (402) close to an opening of the housing (100).
3. The DC motor according to claim 2, characterized in that: The rotor body (402) has six equally divided rotor chip teeth (4021), and a winding groove (4022) is formed between two adjacent rotor chip teeth (4021).
4. The DC motor according to claim 3, characterized in that: The first carbon brush holder (201) and the second carbon brush holder (202) are arranged adjacent to each other; the first carbon brush holder (201) is provided with a first positioning column (213) on one side of the second carbon brush holder (202); the first torsion spring (207) is sleeved on the first positioning column (213); the second carbon brush holder (202) is provided with a second positioning column (214) on one side of the first carbon brush holder (201); the second torsion spring (208) is sleeved on the second positioning column (214); a positioning base (215) is provided between the first positioning column (213) and the second positioning column (214); the first fixed terminal (2072) of the first torsion spring (207) and the second fixed terminal (2082) of the second torsion spring (208) are both located in a slot of the positioning base (215).
5. The DC motor according to claim 4, characterized in that: The first carbon brush holder (201) is provided with a first notch (2011) for avoiding a first movable terminal (2071) of the first torsion spring (207), and the second carbon brush holder (202) is provided with a second notch (2021) for avoiding a second movable terminal (2081) of the second torsion spring (208).
6. The DC motor according to claim 5, characterized in that: A boss (216) is provided between the first connecting terminal (203) and the second connecting terminal (204), and the boss (216) is provided with a first groove (217) for installing a first connecting wire connected to the first connecting terminal (203) and a second groove (218) for installing a second connecting wire connected to the second connecting terminal (204).
7. The DC motor according to claim 6, characterized in that: Four heat dissipation ventilation holes (101) are evenly distributed on the peripheral wall of the housing (100) along the axial direction from close to the end cover (200) to close to the rotor body (402).