Improved stepping motor

Abstract

The utility model discloses an improved stepping motor, which comprises a motor main body, a fixed support and an elastic sheet, the motor main body comprises a metal shell, a stator assembly and a rotor assembly, and the rotor assembly comprises a driving screw rod and a cylindrical magnet; an injection molding bottom cover is arranged at the rear end of the metal shell, the injection molding bottom cover and the metal shell form an integrated structure through injection molding, and a bottom cover through hole is formed in the middle of the injection molding bottom cover. The rear end part of the driving screw rod is in clearance fit with the bottom cover through hole; the rear side of the elastic piece is provided with a blocking piece, the elastic piece and the blocking piece are metal pieces, and the edge portion of the elastic piece and the edge portion of the blocking piece are welded to the rear surface of the metal shell. An elastic tongue piece extending forwards is arranged in the middle of the elastic piece and elastically abuts against the rear end of the driving screw. By means of the structural design, the device has the advantages of being novel in structural design and good in stability and reliability.

Description

Technical Field

[0001] The utility model relates to the technical field of stepping motors, in particular to an improved stepping motor. Background Art

[0002] The Chinese utility model patent with the patent number ZL202020111778.0 and the patent name "A Stepping Motor" discloses the following technical solutions. Specifically: A stepping motor includes a rotor assembly and a stator assembly. The stator assembly surrounds the outside of the rotor assembly. An integrally formed outer shell and a bottom cover plate are fixed to the outside of the stator assembly. The bottom cover plate is located at the tail end of the outer shell. A screw rod is fixedly connected inside the rotor assembly. A bottom cover bearing is arranged at the tail end of the screw rod. A first-stage chrome steel ball is arranged between one end of the bottom cover bearing and the screw rod, and a spring piece is fixedly connected to the other end. The spring piece is used to squeeze the bottom cover bearing to make the bottom cover bearing move forward to squeeze the first-stage chrome steel ball. Several protrusions are distributed on the edge of the spring piece, and the protrusions are in an inverted form. A groove adapted to the protrusions of the spring piece is arranged on the outer surface of the bottom cover plate, and the protrusions are stuck in the groove. A long bracket is fixedly connected to the front end of the outer shell. A first through hole and a second through hole are arranged on the long bracket. The screw rod passes through the first through hole, and the front part of the screw rod abuts against the second through hole.

[0003] It should be noted that for the above stepping motor, it has the following defects. Specifically: The spring piece is snap-fitted and installed on the bottom cover plate through the inverted protrusions at its edge position. The middle part of the spring piece elastically abuts against the bottom cover bearing to realize the extrusion of the screw rod. However, when the reaction force of the load on the screw rod is large, the screw rod will push against the bottom cover bearing and the spring piece, and the spring piece will be disengaged, resulting in poor stability and reliability. Moreover, once the reverse thrust of the screw rod is large, the spring piece will be deformed too much and the elastic force will fail. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an improved stepping motor aiming at the deficiencies of the prior art. The improved stepping motor has a novel structural design and good stability and reliability.

[0005] To achieve the above purpose, the utility model is realized through the following technical solutions.

[0006] An improved stepping motor includes a motor main body, a fixed bracket, and a spring piece. The motor main body includes a metal outer shell welded to the fixed bracket. A stator assembly and a rotor assembly are installed inside the metal outer shell. The rotor assembly includes a driving screw rod and a cylindrical magnet sleeved and fastened around the rear end of the driving screw rod.

[0007] An injection-molded bottom cover is arranged at the rear end of the metal outer shell. The injection-molded bottom cover and the metal outer shell are injection-molded into an integral structure. A bottom cover through hole that completely penetrates from front to back is opened in the middle of the injection-molded bottom cover. The rear end of the driving screw rod is inserted into the bottom cover through hole of the injection-molded bottom cover.

[0008] The rear end of the driving screw is in clearance fit with the through hole of the bottom cover.

[0009] A retaining piece is installed on the rear side of the elastic piece. The elastic piece and the retaining piece are respectively metal parts, and the edge parts of the elastic piece and the retaining piece are respectively welded to the rear surface of the metal shell.

[0010] An elastic tongue extending forward is arranged in the middle of the elastic piece, and the elastic tongue elastically presses against the rear end of the driving screw.

[0011] Wherein, the injection molded bottom cover is provided with at least two positioning convex parts protruding backward.

[0012] The elastic piece and the retaining piece are respectively provided with positioning holes corresponding to the positioning convex parts, and each positioning convex part respectively passes through the corresponding positioning hole of the elastic piece and the corresponding positioning hole of the retaining piece in sequence.

[0013] Wherein, a groove communicated with the through hole of the bottom cover is formed on the rear surface of the injection molded bottom cover, and the elastic tongue of the elastic piece extends into the groove of the injection molded bottom cover.

[0014] Wherein, the metal shell includes a metal front shell and a metal rear shell. The front surface of the metal front shell is welded to the fixed bracket, the rear end of the metal front shell is welded to the front end of the metal rear shell, and the injection molded bottom cover and the metal rear shell are injection molded into an integral structure.

[0015] Wherein, a front bearing is installed at the front end of the fixed bracket, and the front bearing is provided with a bearing blind hole opening backward.

[0016] The front end of the driving screw is inserted into the bearing blind hole of the front bearing, and the front end of the driving screw is in clearance fit with the bearing blind hole.

[0017] Wherein, the front end face and the rear end face of the driving screw are respectively spherical surfaces, and the elastic tongue elastically presses against the spherical surface of the rear end of the driving screw.

[0018] Compared with the prior art, the utility model has the following beneficial effects. Specifically:

[0019] 1. During the process of the driving screw driving the load to act, when the load acts on the driving screw with a large reaction force, the rear end of the driving screw will push the elastic tongue of the elastic piece backward, and the elastic tongue can play a buffering role; once the elastic tongue abuts against the front surface of the retaining piece, the retaining piece can prevent the elastic tongue from being excessively bent and deformed.

[0020] 2. The elastic piece and the retaining piece are respectively welded to the metal shell of the motor body. This structural design can effectively avoid the problem of the elastic piece falling off under the action of the reaction force of the driving screw, and has good stability and reliability.

[0021] 3. Therefore, the improved stepping motor of the present utility model has the advantages of novel structural design, good stability and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present utility model will be further described below with reference to the drawings, but the embodiments in the drawings do not constitute any limitation to the present utility model.

[0023] Figure 1 It is a schematic structural diagram of the present utility model.

[0024] Figure 2 It is an exploded schematic diagram of the present utility model.

[0025] Figure 3 It is a sectional schematic diagram of the present utility model.

[0026] Figure 4 It is Figure 3 a partially enlarged schematic diagram.

[0027] Figure 5 It is Figure 3 a partially enlarged schematic diagram at another position.

[0028] In Figures 1 to 5 it includes:

[0029] 1 - Motor body; 11 - Metal housing; 111 - Metal front housing; 112 - Metal rear housing; 13 - Rotor assembly; 131 - Drive screw; 132 - Cylindrical magnet; 12 - Injection - molded bottom cover; 121 - Bottom - cover through - hole; 122 - Positioning convex part; 123 - Groove; 2 - Fixed bracket; 3 - Elastic sheet; 31 - Elastic tongue; 4 - Retaining plate; 5 - Positioning hole; 6 - Front - end bearing; 61 - Bearing blind hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present utility model will be described below in conjunction with specific embodiments.

[0031] Embodiment 1, as Figures 1 to 3 shown, an improved stepping motor includes a motor body 1, a fixed bracket 2, and an elastic sheet 3. The motor body 1 includes a metal housing 11 welded to the fixed bracket 2. Inside the metal housing 11, a stator assembly and a rotor assembly 13 are installed. The rotor assembly 13 includes a drive screw 131 and a cylindrical magnet 132 sleeved and fastened around the rear end of the drive screw 131.

[0032] Among them, as Figure 2 , Figure 3 and Figure 5As shown in the figure, an injection molded bottom cover 12 is provided at the rear end of the metal housing 11. The injection molded bottom cover 12 and the metal housing 11 are injection molded into an integral structure. A bottom cover through hole 121 that penetrates completely from front to back is provided in the middle of the injection molded bottom cover 12. The rear end of the drive screw 131 is inserted into the bottom cover through hole 121 of the injection molded bottom cover 12.

[0033] Furthermore, the rear end of the drive screw 131 is in clearance fit with the bottom cover through hole 121.

[0034] Even further, as shown in Figure 1 , Figure 2 , Figure 3 and Figure 5 shown, a retaining piece 4 is installed on the rear side of the elastic piece 3. The elastic piece 3 and the retaining piece 4 are respectively metal parts, and the edge parts of the elastic piece 3 and the retaining piece 4 are respectively welded to the rear surface of the metal housing 11.

[0035] In addition, an elastic tongue piece 31 extending forward is provided in the middle of the elastic piece 3. The elastic tongue piece 31 elastically presses against the rear end of the drive screw 131.

[0036] When the improved stepping motor in the first embodiment works, after the coil winding in the stator assembly is energized, it drives the cylindrical magnet 132 to rotate. The rotating cylindrical magnet 132 drives the drive screw 131 to rotate synchronously.

[0037] During the process of the drive screw 131 driving the load to act in the first embodiment, when the load acts on the drive screw 131 with a large reaction force, the rear end of the drive screw 131 will push the elastic tongue piece 31 of the elastic piece 3 backward. The elastic tongue piece 31 can play a buffering role; once the elastic tongue piece 31 abuts against the front surface of the retaining piece 4, the retaining piece 4 can prevent the elastic tongue piece 31 from bending and deforming excessively.

[0038] In addition, the elastic piece 3 and the retaining piece 4 in the first embodiment are respectively welded to the metal housing 11 of the motor body 1. This structural design can effectively avoid the problem of the elastic piece 3 falling off under the action of the reaction force of the drive screw 131, and has good stability and reliability.

[0039] Based on the above situation, through the above structural design, the improved stepping motor in the first embodiment has the advantages of novel structural design, good stability and reliability.

[0040] Embodiment 2, as shown in Figure 1 , Figure 2 , Figure 3 and Figure 5 shown, the difference between the second embodiment and the first embodiment is that: the injection molded bottom cover 12 is provided with at least two positioning convex portions 122 protruding backward.

[0041] Among them, the elastic piece 3 and the retaining piece 4 are respectively provided with positioning holes 5 corresponding to the positioning convex portions 122, and each positioning convex portion 122 sequentially passes through the corresponding positioning hole 5 of the elastic piece 3 and the corresponding positioning hole 5 of the retaining piece 4.

[0042] During the welding process of the elastic piece 3 and the retaining piece 4, through the cooperation of the positioning convex portion 122 and the positioning hole 5, the second embodiment can realize the rapid installation and positioning of the elastic piece 3 and the retaining piece 4.

[0043] Embodiment Three, as Figure 2 , Figure 3 and Figure 5 shown, the difference between the third embodiment and the first embodiment is that: a groove 123 communicating with the bottom cover through hole 121 is formed on the rear surface of the injection molded bottom cover 12, and the elastic tongue 31 of the elastic piece 3 extends into the groove 123 of the injection molded bottom cover 12.

[0044] For the groove 123 structure of this third embodiment, it can provide a clearance space for the elastic tongue 31 of the elastic piece 3, and this structural design can improve the compactness of the structure.

[0045] Embodiment Four, as Figure 1 , Figure 2 , Figure 3 and Figure 5 shown, the difference between the fourth embodiment and the first embodiment is that: the metal shell 11 includes a metal front shell 111 and a metal rear shell 112. The front surface of the metal front shell 111 is welded to the fixed bracket 2, the rear end of the metal front shell 111 is welded to the front end of the metal rear shell 112, and the injection molded bottom cover is injection molded into an integral structure with the metal rear shell 112.

[0046] Embodiment Five, as Figures 1 to 4 shown, the difference between the fifth embodiment and the first embodiment is that: a front end bearing 6 is installed at the front end of the fixed bracket 2, and the front end bearing 6 is provided with a bearing blind hole 61 opening backward; the front end of the driving screw 131 is inserted into the bearing blind hole 61 of the front end bearing 6, and the front end of the driving screw 131 is in clearance fit with the bearing blind hole 61.

[0047] Embodiment Six, as Figures 3 to 5 shown, the difference between the sixth embodiment and the fifth embodiment is that: the front end face and the rear end face of the driving screw 131 are spherical surfaces, and the elastic tongue 31 elastically presses against the spherical surface at the rear end of the driving screw 131.

[0048] By designing the front end face and the rear end face of the driving screw 131 as spherical surfaces respectively, that is, the front end part and the rear end part of the driving screw 131 are spherical head structures respectively. On the one hand, the above spherical head structure design can improve the convenience during assembly alignment to improve the assembly efficiency. On the other hand, it can reduce the friction between the driving screw 131 and the front bearing 6 on the front end side and the elastic sheet 3 on the rear end side, so that the driving screw 131 rotates more smoothly.

[0049] The above content is only the preferred embodiment of the present utility model. For those of ordinary skill in the art, according to the idea of the present utility model, there will be changes in the specific implementation manners and application scopes. The content of this specification should not be construed as a limitation to the present utility model.

Claims

1. An improved stepping motor, comprising a motor body (1), a fixing bracket (2), and a spring (3), wherein the motor body (1) comprises a metal shell (11) welded to the fixing bracket (2), a stator assembly and a rotor assembly (13) are mounted inside the metal shell (11), and the rotor assembly (13) comprises a driving screw (131) and a cylindrical magnet (132) sleeved and fastened to the outer periphery of the rear end of the driving screw (131); An injection molded bottom cover (12) is provided at the rear end of the metal shell (11), the injection molded bottom cover (12) and the metal shell (11) are injection molded into an integral structure, a bottom cover through hole (121) that completely penetrates the middle of the injection molded bottom cover (12) is provided, and the rear end of the driving screw (131) is inserted into the bottom cover through hole (121) of the injection molded bottom cover (12); Features: The rear end of the driving screw rod (131) is clearance-matched with the bottom cover through hole (121); A baffle (4) is mounted on the rear side of the spring piece (3); the spring piece (3) and the baffle (4) are respectively metal parts, and the edges of the spring piece (3) and the baffle (4) are respectively welded to the rear surface of the metal housing (11); An elastic tongue (31) extending forward is arranged in the middle of the spring sheet (3), and the elastic tongue (31) elastically presses against the rear end of the driving screw rod (131).

2. The improved stepping motor according to claim 1, characterized in that: The injection molded bottom cover (12) is provided with at least two positioning protrusions (122) protruding backwards; The spring sheet (3) and the baffle sheet (4) are respectively provided with positioning holes (5) corresponding to the positioning protrusions (122), and each positioning protrusion (122) passes through the corresponding positioning hole (5) of the spring sheet (3) and the corresponding positioning hole (5) of the baffle sheet (4) in sequence.

3. The improved stepping motor according to claim 1, characterized in that: A groove (123) communicating with the bottom cover through hole (121) is formed on the rear surface of the injection-molded bottom cover (12), and the elastic tongue (31) of the elastic sheet (3) extends into the groove (123) of the injection-molded bottom cover (12).

4. The improved stepping motor according to claim 1, characterized in that: The metal shell (11) comprises a metal front shell (111) and a metal rear shell (112); the front surface of the metal front shell (111) is welded to the fixing bracket (2); the rear end of the metal front shell (111) is welded to the front end of the metal rear shell (112); and the injection-molded bottom cover (12) and the metal rear shell (112) are injection-molded into an integral structure.

5. The improved stepping motor according to claim 1, characterized in that: A front end portion of the fixed bracket (2) is provided with a front end bearing (6), and the front end bearing (6) is provided with a bearing blind hole (61) opening toward the rear; The front end portion of the driving screw rod (131) is inserted into the bearing blind hole (61) of the front end bearing (6), and the front end portion of the driving screw rod (131) is clearance-matched with the bearing blind hole (61).

6. The improved stepping motor according to claim 5, characterized in that: The front end face and the rear end face of the driving screw rod (131) are spherical surfaces respectively, and the elastic tongue piece (31) elastically presses against the spherical surface of the rear end of the driving screw rod (131).

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