Brush motor

Abstract

The utility model relates to the technical field of motors, in particular to a brush motor. The utility model discloses a brush motor, which comprises a shell, a front end cover and a rear end cover, the front end cover and the rear end cover are respectively arranged at two axial ends of the shell, a rotor shaft is rotatably supported between the front end cover and the rear end cover, a rotor is fixedly arranged on the excircle surface of the rotor shaft, and a brush carrier plate is arranged at one end, close to the rear end cover, in the shell. A carbon brush assembly is fixedly arranged on the brush carrier plate, a plane part is arranged on the edge of the brush carrier plate close to the carbon brush assembly, a receding space is formed between the plane part and the rear end cover, and powder storage grooves are formed in the rear end cover and correspond to the two ends of the carbon brush assembly. The carbon powder brush holder has the advantages that carbon powder can be prevented from being accumulated on the brush holder plate, and electric leakage or withstand voltage breakdown is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor technical field, concretely is a brush motor. BACKGROUND

[0002] The Chinese patent application with the application number 201620610154.7 discloses a brush motor brush holder, which comprises a brush holder plate, a plurality of electric brushes, a plurality of brush holders and a plurality of backing plates, the number of the electric brushes, the number of the brush holders and the number of the backing plates are the same, the electric brushes are located in the brush holders, the left and right sides of the brush holders are formed with outward convex structures to make the brush holders drum-shaped, the outward convex structures of the brush holders are provided with slots, each backing plate is provided with a first brush holder fixing port, and the brush holder plate is provided with second brush holder fixing ports which are adapted to the positions and number of the first brush holder fixing ports.

[0003] The existing brush motor is usually arranged with a circuit board on the brush holder plate away from the rear end cover during installation, so as to protect the circuit board. However, when the brush motor is working, the carbon powder generated in the rotating process of the carbon brush will fall on the circuit board, and then the carbon powder will continuously cover the inside of the motor. After the voltage breakdown test, it is found that there are breakdown points on the circuit board, so that the motor current leakage occurs, which affects the power supply operation of the motor. In the above technical solution, since the brush holder plate is only arranged in a conventional shape, the carbon powder cannot flow and can only accumulate on the circuit board, causing current leakage or voltage breakdown. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a brush motor which can make the carbon powder flow to the back side of the brush holder plate to prevent the carbon powder from accumulating on the circuit board.

[0005] To achieve the above-mentioned purpose, the utility model discloses a brush motor, which comprises a shell, a front end cover and a rear end cover arranged at the two axial ends of the shell respectively, a rotor shaft rotatably supported between the front end cover and the rear end cover, a rotor fixedly arranged on the outer circular surface of the rotor shaft, a brush holder plate arranged in the shell close to one end of the rear end cover, a circuit board arranged in the shell close to one end of the rear end cover along the axial direction of the motor, a carbon brush assembly fixedly arranged on the brush holder plate, a flat part arranged on the edge of the brush holder plate close to the carbon brush assembly, a space formed between the flat part on the brush holder plate and the rear end cover, and a powder storage groove formed on the rear end cover corresponding to the two ends of the carbon brush assembly.

[0006] When the motor is working, the carbon brush assembly will generate carbon powder due to abrasion caused by its rotation. At this time, since the space is formed between the flat part on the brush holder plate and the rear end cover, the space serves as a channel for the flow of the carbon powder, so that the carbon powder can flow after covering the circuit board, flow between the rear end cover and the back surface of the brush holder plate, and cover the surface of the rear end cover and the surface of the powder storage groove, thereby avoiding the continuous accumulation of the carbon powder on the circuit board.

[0007] The utility model discloses a set up the powder storage groove on the rear end cover, and then the surface area of rear end cover increases, thereby increasing carbon powder adsorption capacity, and the planar portion is set to the position of carbon brush assembly on the brush holder plate edge, and the space is formed between the brush holder plate and the rear end cover, which effectively changes the accumulation path of carbon powder, when the carbon powder produced by carbon brush assembly abrasion scatters, the carbon powder will cover on the circuit board first, but due to the existence of the space, the carbon powder can continue to flow to the rear end cover and the back of the brush holder plate, thereby avoiding the continuous accumulation of carbon powder on the circuit board, the utility model has the advantages of preventing carbon powder from accumulating on the circuit board, avoiding causing electric leakage or withstand voltage breakdown.

[0008] As preferred, the rear end cover is provided with an expansion groove on both sides of the powder storage groove and extending circumferentially along the rear end cover.

[0009] By further adding the expansion groove on both sides of the powder storage groove, the surface area of the rear end cover can be further increased, thereby increasing the carbon powder adsorption capacity.

[0010] The powder storage groove and the expansion groove can be any cross-section groove without affecting the use of the rear end cover, such as a circular cross-section groove, a square cross-section groove, or a groove with a hemispherical bottom.

[0011] As preferred, the rear end cover is further provided with an opening communicating with the powder storage groove.

[0012] The opening is used to increase the width of the space between the planar portion of the brush holder plate and the rear end cover, thereby increasing the carbon powder flow.

[0013] As preferred, the rear end cover is further provided with an opening communicating with the powder storage groove and the expansion groove.

[0014] By setting the opening communicating with the powder storage groove and the expansion groove, not only the width of the space between the planar portion of the brush holder plate and the rear end cover can be increased, but also the width of the opening can be increased, thereby further increasing the carbon powder flow.

[0015] As preferred, the depth of the opening is less than the depth of the expansion groove, and the opening forms a step at the groove opening of the powder storage groove.

[0016] By reducing the depth of the opening, a step extending from the opening to both sides is formed at the groove opening of the powder storage groove, which ensures the width between the planar portion of the brush holder plate and the rear end cover and the structural strength of the groove wall of the powder storage groove and the expansion groove, thereby ensuring the use effect of the rear end cover and the sealing effect between the rear end cover and the shell.

[0017] As preferred, the rotor shaft is provided with a commutator, which is located between the brush holder plate circuit board and the rotor.

[0018] The current direction in the armature winding is changed by the commutator to ensure that the electromagnetic torque direction is always unchanged, so that the rotor shaft can continue to rotate.

[0019] As preferred, the axial both ends of the rotor are provided with rotor insulating sheets, which include a mounting part in a straight cylinder shape and an extension part arranged in an annular array on the outer circumferential surface of the mounting part at one axial end, and the extension part corresponds to the punching sheet of the rotor one by one, and the rotor insulating sheet avoids the direct contact between the enameled wire and the rotor shaft during winding of the rotor, thereby preventing breakdown.

[0020] As preferred, the commutator is provided with an annular groove near the center position of one end of the rotor, and the axial end of the mounting part is matched with the annular groove and embedded in the annular groove, and the mounting part is tightly matched with the rotor shaft, thereby ensuring the coaxial degree between the rotor insulating sheet and the rotor shaft and the rotor, preventing the rotor insulating sheet from deviating and ensuring the stability of the rotor insulating sheet when rotating with the rotor shaft.

[0021] The carbon powder can flow to the back end cover and the back surface of the brush holder plate, thereby avoiding continuous accumulation of the carbon powder on the brush holder plate circuit board, and the carbon powder can be prevented from accumulating on the brush holder plate circuit board, and the advantages of avoiding causing leakage or withstand voltage breakdown are achieved. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structural schematic view of the utility model.

[0023] Figure 2 It is an exploded structural schematic view of the utility model.

[0024] Figure 3 It is another exploded structural schematic view of the utility model.

[0025] Figure 4 It is a sectional structural schematic view of the utility model.

[0026] Figure 5 It is a structural schematic view of the back end cover in the utility model.

[0027] In the drawing: 11, shell; 12, front end cover; 13, back end cover; 131, powder storage groove; 132, expansion groove; 133, opening; 14, brush holder plate; 141, plane part; 142, accommodation space; 15, circuit board; 16, carbon brush assembly; 17, rotor shaft; 18, rotor; 19, commutator; 20, annular groove; 21, rotor insulating sheet; 211, mounting part; 212, extension part. DETAILED DESCRIPTION

[0028] The utility model will be further described below according to the drawings and specific embodiments.

[0029] As shown by Figure 1 The embodiment discloses a brush motor, which comprises a shell 11, a front end cover 12 and a rear end cover 13 arranged at the axial two ends of the shell 11 respectively, a rotor shaft 17 rotationally supported between the front end cover 12 and the rear end cover 13, a rotor 18 fixedly arranged on the outer circumferential surface of the rotor shaft 17, a brush holder plate 14 and a circuit board 15 arranged in sequence along the motor axial direction in the shell 11 close to one end of the rear end cover 13, a commutator 19 arranged on the rotor shaft 17, the commutator 19 being located between the brush holder plate 14, the circuit board 15 and the rotor 18, and a carbon brush assembly 16 fixedly arranged on the brush holder plate 14. Figure 4 As shown by Figure 4 The brush holder plate 14 is provided with a flat portion 141 close to the carbon brush assembly 16, and the flat portion 141 and the rear end cover 13 form a space 142.

[0030] As shown by Figure 5 The rear end cover 13 is provided with a powder storage groove 131 corresponding to the two ends of the carbon brush assembly 16, an extension groove 132 extending along the circumferential direction of the rear end cover 13 and located on the two sides of the powder storage groove 131, and an opening 133 in communication with the powder storage groove 131 and the extension groove 132, the depth of the opening 133 being smaller than the depth of the extension groove 132, and the opening 133 forming a step at the opening of the powder storage groove 131.

[0031] As shown by Figure 2 The axial two ends of the rotor 18 are provided with rotor insulating sheets 21, which can avoid improper installation of the rotor 18 during winding and direct contact between the enameled wire and the rotor shaft 17 during winding of the rotor 18, thereby preventing breakdown. Figure 3 As shown by The rotor insulating sheet 21 comprises a mounting portion 211 in a straight cylinder shape and an extension portion 212 arranged in an annular array on the axial one end of the outer circumferential surface of the mounting portion 211, the extension portion 212 corresponding to the punching sheet of the rotor 18 in one-to-one correspondence, the commutator 19 is provided with an annular groove 20 at the central position close to the one end of the rotor 18, the axial one end of the mounting portion 211 is matched with the annular groove 20 and embedded in the annular groove 20, and the mounting portion 211 is tightly fitted with the rotor shaft 17.

[0032] First, the brush holder plate 14 is installed together with the circuit board 15 to the rear end cover 13, and then the front end cover 12 and the rear end cover 13 are installed to the axial ends of the shell 11. When the motor is working, the carbon brush assembly 16 is worn due to its own rotation, resulting in the scattering of carbon powder. At this time, the flat part 141 on the brush holder plate 14 and the rear end cover 13 form a space 142, which serves as a channel for the flow of carbon powder. After the carbon powder covers the brush holder plate 14 and the circuit board 15, it flows through the space 142 to the space between the rear end cover 13 and the back of the brush holder plate 14, and covers the surface of the rear end cover 13, the surface of the powder storage groove 131 and the surface of the expansion groove 132, thereby avoiding the continuous accumulation of subsequent scattered carbon powder on the brush holder plate 14 and the circuit board 15.

Claims

1. A brush motor comprising a housing, a front end cover and a rear end cover arranged at axial two ends of the housing respectively, a rotor shaft being rotationally supported between the front end cover and the rear end cover, a rotor being fixedly arranged on an outer circumferential surface of the rotor shaft, and a brush holder plate being arranged in the housing close to an end of the rear end cover, characterized in that: The brush holder plate is fixed with a carbon brush assembly, and a flat part is arranged on the edge of the brush holder plate close to the carbon brush assembly, forming a space between the flat part and the rear end cover.

2. A brushed electric motor according to claim 1, characterized in that: The rear end cover is provided with an extension groove on both sides of the powder storage groove and extending along the circumference of the rear end cover.

3. A brushed electric motor according to claim 1, characterized in that: The rear end cover is further provided with an opening communicating with the powder storage groove.

4. A brushed electric motor according to claim 2, characterized in that: The rear end cover is further provided with an opening communicating with the powder storage groove and the extension groove.

5. A brushed electric motor according to claim 3 or 4, characterized in that: The depth of the opening is less than that of the extension groove, and the opening forms a step at the opening of the powder storage groove.

6. A brushed electric motor according to claim 1, characterized in that: The rotor shaft is provided with a commutator, and the commutator is located between the brush holder plate and the rotor.

7. A brushed electric motor according to claim 6, characterized in that: The axial ends of the rotor are provided with rotor insulating sheets, which include a straight cylindrical mounting part and an extension part arranged in an annular array on the outer circumferential surface of the mounting part at one axial end, and the extension part corresponds to the stamping sheet of the rotor one by one.

8. A brushed electric motor according to claim 7, characterized in that: The center of one end of the commutator close to the rotor is provided with an annular groove, and the axial end of the mounting part is matched with the annular groove and embedded in the annular groove, and the mounting part is tightly fitted with the rotor shaft.

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