direct current motor

Abstract

A direct current motor comprises a casing, a permanent magnet accommodated in the casing, and a front end cover and a rear end cover located at opposite ends of the casing, the permanent magnet is formed with a positioning slot, the front end cover is protruded with a first abutting portion and a first limiting portion towards the rear end cover, the rear end cover is protruded with a second abutting portion towards the front end cover, the first abutting portion and the second abutting portion abut opposite ends of the permanent magnet respectively, so that the permanent magnet is axially fixed, the first limiting portion is accommodated in the positioning slot and the edge thereof abuts the edge of the positioning slot, so that the permanent magnet is radially fixed; thus, the unstable performance of the motor caused by coating glue and the complicated installation caused by coating glue and using a clasp spring are avoided, and the purposes of stabilizing the performance of the motor and improving the installation efficiency are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the motor technical field, specifically relates to a direct current motor. BACKGROUND

[0002] The traditional direct current motor includes a casing, a stator accommodated in the casing and a rotor matched with the stator. The stator includes permanent magnets which are fixed on the casing by means of glue and a clamping spring. In order to firmly bond the permanent magnets with the casing, the glue needs to be pre-mixed according to a specific proportion and then coated on the surface of the permanent magnets and the casing to be bonded. Since the glue has a certain fluidity, it is easy to cause uneven distribution in the coating and bonding process, so that the inner diameter size of the casing is likely to deviate, which indirectly affects the stability of the motor performance. Meanwhile, the glue is extremely easy to be left on other parts of the casing which are not bonded with the permanent magnets through extrusion and flow, thereby affecting the assembly of other components. SUMMARY

[0003] Therefore, the present application provides a direct current motor which includes a casing, permanent magnets accommodated in the casing and front and rear end covers located at opposite ends of the casing. Positioning grooves are formed on the permanent magnets. The front end cover protrudes a first abutting portion and a first limiting portion towards the rear end cover. The rear end cover protrudes a second abutting portion towards the front end cover. The first and second abutting portions abut opposite ends of the permanent magnets respectively, so that the permanent magnets are axially fixed. The first limiting portion is accommodated in the positioning groove and its edge abuts the edge of the positioning groove, so that the permanent magnets are radially fixed.

[0004] Further, the first and second abutting portions are arranged opposite to each other.

[0005] In some embodiments, the front end cover includes a ring-shaped first connecting portion. The first abutting portion is a plurality of spaced pieces protruding from the edge of the first connecting portion, and the top end of the first abutting portion abuts the end of the permanent magnet.

[0006] Further, the first limiting portion is a piece protruding from the first connecting portion, and the protruding length of the first limiting portion is longer than the length of the first abutting portion.

[0007] Further, the number of the first limiting portions is two, and the two first limiting portions are spaced. Two spaced positioning grooves are formed on the permanent magnets, and the two first limiting portions are accommodated in the corresponding positioning grooves respectively.

[0008] Further, the two first limiting portions are symmetrically arranged.

[0009] In some embodiments, the second abutting portion protrudes a pre-pressing column towards the top end of the permanent magnet, which is used to elastically abut the permanent magnet.

[0010] Further, the rear end cover comprises a second connecting part in a ring shape, the second abutting part is a plurality of spaced-apart pieces protruding from the edge of the second connecting part, and the pre-pressing column is arranged at the top end of each piece.

[0011] Further, the number of the second limiting parts is two, the two second limiting parts are arranged at intervals, the permanent magnet is formed with two spaced-apart positioning grooves, and the two second limiting parts are respectively accommodated in the corresponding positioning grooves.

[0012] Further, the two second limiting parts are symmetrically arranged.

[0013] In the present application, the first abutting part and the second abutting part abut the opposite ends of the permanent magnet respectively, so that the permanent magnet is axially fixed, the first limiting part is accommodated in the positioning groove and the edge thereof abuts the edge of the positioning groove, so that the permanent magnet is radially fixed. In this way, the instability of the motor performance caused by the coating of glue and the complicated installation caused by the coating of glue and the use of a clasp spring are avoided, and the purposes of stabilizing the motor performance and improving the installation efficiency are achieved. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a perspective assembly view of the motor of an embodiment of the present application.

[0015] Figure 2 It is a perspective assembly view of the motor of an embodiment of the present application. Figure 1 It is a perspective exploded view of the motor shown.

[0016] Figure 3 It is a sectional view of the motor shown. Figure 1 It is a sectional view of the motor shown.

[0017] Figure 4 It is a perspective view of the rear end cover of the motor shown. Figure 1 It is a perspective view of the rear end cover of the motor shown.

[0018] Figure 5 It is a perspective view of the front end cover of the motor shown. Figure 1 It is a perspective view of the front end cover of the motor shown. DETAILED DESCRIPTION

[0019] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments, so that the technical solutions of the present application and their beneficial effects are more clear and understandable. It can be understood that the drawings are provided for reference and illustration only, and are not intended to limit the present application, and the sizes shown in the drawings are only for clear description, and do not limit the proportional relationship.

[0020] Reference Figures 1 to 3The direct current motor of one embodiment of the present application comprises a casing 10, a permanent magnet 20 accommodated in the casing 10, and a front end cover 30 and a rear end cover 40 located at opposite ends of the casing 10. The front end cover 30 and the rear end cover 40 act on opposite ends of the permanent magnet 20, thereby fixing the permanent magnet 20 axially and radially.

[0021] The permanent magnet 20 is composed of two spaced and opposite plates, and two positioning grooves 21 are formed between the two plates along the length direction of the permanent magnet 20.

[0022] Please refer to Figure 4 and Figure 5 The front end cover 30 comprises a ring-shaped first connecting portion 31, a first abutting portion 33 protruding from the first connecting portion 31 toward the edge of the rear end cover 40, and a first limiting portion 35. The outer diameter of the first connecting portion 31 is slightly smaller than the inner diameter of the casing 10, so that the first connecting portion 31 is accommodated in the casing 10. The first abutting portion 33 is a plurality of spaced plates protruding from the edge of the first connecting portion 31, and the top end of the plates is used to abut one end of the permanent magnet 20. In this embodiment, the number of the plates is four, and the plates are symmetrically arranged at the upper and lower ends of the first connecting portion 31. The first limiting portion 35 is a plate protruding from the first connecting portion 31, and the protruding length of the plate exceeds the length of the first abutting portion 33. In this embodiment, the number of the first limiting portion 35 is two, and the two first limiting portions 35 are symmetrically arranged and accommodated in one end of the corresponding positioning groove 21, and the edge of the first limiting portion 35 abuts the edge of the positioning groove 21. The first limiting portion 35 is a U-shaped plate with an opening in the middle. A plurality of spaced first lugs 37 protrude from the outer periphery of the first connecting portion 31. The first lugs 37 are located at the end of the first connecting portion 31 away from the first abutting portion 33, and when the first connecting portion 31 is accommodated in the casing 10, the end of the casing 10 abuts the first lugs 37.

[0023] The rear end cover 40 comprises a ring-shaped second connecting portion 41, a second abutting portion 43 protruding from the second connecting portion 41 towards the edge of the front end cover 30, and a second limiting portion 45. The outer diameter of the second connecting portion 41 is slightly smaller than the inner diameter of the casing 10, so that the second connecting portion 41 is accommodated in the casing 10. The second abutting portion 43 is a plurality of spaced-apart pieces protruding from the edge of the second connecting portion 41, each piece having a pre-pressing column 46 protruding towards the top end of the front end cover 30, for elastically abutting against the other end of the permanent magnet 20. In the present embodiment, the number of the pieces is four, and the pieces are symmetrically arranged at the upper and lower ends of the second connecting portion 41. Each pre-pressing column 46 is a boss gradually decreasing outward from the second abutting portion 43. The second limiting portion 45 is a piece protruding from the second connecting portion 41, and the protruding length of the second limiting portion 45 is longer than the length of the second abutting portion 43. In the present embodiment, the number of the second limiting portions 45 is two, and the two second limiting portions 45 are symmetrically arranged at intervals and respectively accommodated in the other end of the corresponding positioning groove 21, with the edge of the second limiting portion 45 abutting against the edge of the positioning groove 21. The second limiting portion 45 is a U-shaped piece with an opening in the middle. The first abutting portion 33 and the second abutting portion 43 are arranged opposite to each other. A plurality of second lugs 47 are arranged at intervals from the outer periphery of the second connecting portion 41. The second lugs 47 are located at the end of the second connecting portion 41 away from the second abutting portion 43, and when the second connecting portion 41 is accommodated in the casing 10, the end of the casing 10 abuts against the second lugs 47.

[0024] In the present application, the first abutting portion 33 and the second abutting portion 43 abut against the opposite ends of the permanent magnet 20 respectively, so that the permanent magnet 20 is axially fixed, and the first limiting portion 35 and the second limiting portion 45 are accommodated in the positioning groove 21 with the edge of the first limiting portion 35 and the second limiting portion 45 abutting against the edge of the positioning groove 21, so that the permanent magnet 20 is radially fixed. In this way, the instability of the motor performance caused by coating glue and the complicated installation caused by coating glue and using a circlip are avoided, and the purposes of stabilizing the motor performance and improving the installation efficiency are achieved.

[0025] The above merely describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any simple changes or equivalent replacements of the technical solutions within the technical scope disclosed by the present application are all within the protection scope of the present application.

Claims

1. A direct current motor comprising a housing, a permanent magnet housed in the housing, and a front end cover and a rear end cover located at opposite ends of the housing, characterized in that: The permanent magnet is provided with a positioning slot, the front end cover is provided with a first abutting part and a first limiting part protruding towards the rear end cover, the rear end cover is provided with a second abutting part protruding towards the front end cover, the first and second abutting parts abut against opposite ends of the permanent magnet respectively, so that the permanent magnet is axially fixed, the first limiting part is accommodated in the positioning slot and its edge abuts against the edge of the positioning slot, so that the permanent magnet is radially fixed; the first limiting part is provided with an opening in the middle; the second abutting part is provided with a pre-pressing column protruding towards the top end of the permanent magnet, used for elastically abutting against the permanent magnet, the pre-pressing column gradually decreases from the second abutting part outward; the permanent magnet is used for forming a stator. The rear end cover comprises a ring-shaped second connecting part and a second limiting part protruding from the edge of the second connecting part towards the front end cover; the second limiting part is provided with an opening in the middle and is accommodated in the other end of the corresponding positioning slot.

2. The direct current motor of claim 1, wherein, The first and second abutting parts are arranged opposite to each other.

3. The direct current motor of claim 1, wherein, The front end cover comprises a ring-shaped first connecting part, the first abutting part is a plurality of spaced pieces protruding from the edge of the first connecting part, and the top end of the first abutting part abuts against the end of the permanent magnet.

4. The direct current motor of claim 3, wherein, The first limiting part is a piece protruding from the first connecting part, and the protruding length of the first limiting part is longer than the length of the first abutting part.

5. The direct current motor of claim 3, wherein, The number of the first limiting parts is two, the two first limiting parts are arranged at intervals, the permanent magnet is provided with two spaced positioning slots, and the two first limiting parts are accommodated in the corresponding positioning slots respectively.

6. The direct current motor of claim 5, wherein, The two first limiting parts are symmetrically arranged.

7. The direct current motor of claim 1, wherein, The second abutting part is a plurality of spaced pieces protruding from the edge of the second connecting part, and the pre-pressing column is arranged at the top end of each piece.

8. The direct current motor of claim 7, wherein, The number of the second limiting parts is two, the two second limiting parts are arranged at intervals, the permanent magnet is provided with two spaced positioning slots, and the two second limiting parts are accommodated in the corresponding positioning slots respectively.

9. The direct current motor of claim 8, wherein, The two second limiting parts are symmetrically arranged.

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