A stepper motor

Abstract

The present invention relates to a stepping motor, which comprises a housing and a socket installed at the rear end of the housing, as well as a stator assembly and a rotor assembly arranged in the housing. The stator assembly includes a stator body and an integral stator housing sleeved outside the stator body. Two coil grooves for placing coils are arranged in parallel on the outer ring surface of the stator body. At the top of the rear side wall of the coil groove located at the rear side, there are pins connected to the coils. The rotor assembly includes a rotor body and a transmission lead screw threadedly engaged in the shaft hole of the rotor body. An annular groove is arranged on the outer ring surface of the rotor body, a limiting step is arranged at the rear side of the annular groove, at least two U-shaped notches are arranged at the rear end of the rotor body, and a bearing with an outer ring connected to the stator body is installed in the annular groove. An insertion pin with an upper end rigidly connected to the pin is arranged in the socket. The overall structure of the present invention is simple, which reduces the assembly difficulty, reduces the occurrence of faults, and ensures the normal use of the stepping motor.

Description

Technical Field

[0001] The invention belongs to the technical field of stepping motors, and in particular relates to a stepping motor. Background Art

[0002] The stator housing of a traditional stepper motor, such as an idle stepper motor, is split, with two coils corresponding to two stator housings, and the two stator housings are installed relative to each other, which increases the complexity of the entire stator structure and the cumbersomeness of the installation steps.

[0003] The rotor needs to be connected to the stator by means of bearings, wherein the inner ring of the bearing is fixed to the rotor, and the outer ring is fixed to the stator. Traditional stepper motors all install a fixed part on the rotor body to fix the position of the bearing, which further increases the complexity of the stepper motor structure and the cost of use. Moreover, after long-term use, parts are prone to shifting or falling off, causing bearing shaking problems.

[0004] In addition, the pins in the socket of the existing stepper motor and the pins connected to the coil are generally connected by soft wires, and it is necessary to ensure that both ends of the wires are well connected, which increases the difficulty of installation. In addition, the wires are placed directly in the casing, and the coils of the stepper motors will generate heat during operation. The wires are very prone to failure in a high temperature environment for a long time, which in turn causes poor contact between the pins and the pins, directly affecting the normal use of the stepper motor. Summary of the invention

[0005] The purpose of the present invention is to provide a stepping motor to solve the problem of complex structure of the stepping motor.

[0006] A stepping motor of the present invention is implemented as follows:

[0007] A stepper motor comprises a housing and a socket mounted at the rear end of the housing, and a stator assembly and a rotor assembly arranged in the housing, wherein:

[0008] The stator assembly includes a stator body and an integrated stator housing sleeved on the outside of the stator body. Two coil slots for placing coils are arranged in parallel on the outer ring surface of the stator body, and a pin connected to the coil is arranged on the top of the rear side wall of the coil slot located on the rear side;

[0009] The rotor assembly comprises a rotor body and a transmission screw threadedly engaged in the shaft hole of the rotor body, an annular groove is arranged on the outer ring surface of the rotor body, a limited position step is arranged on the rear side of the annular groove, at least two U-shaped notches are arranged at the rear end of the rotor body, and a bearing whose outer ring is connected to the stator body is installed in the annular groove;

[0010] The socket is provided with a plug pin whose upper end is rigidly connected to the pin.

[0011] Further, a wire groove is provided at the top of the side wall located between two coil slots.

[0012] Further, pole plates integrally injection-molded with the stator body are provided inside the side walls on both sides of each coil slot, and the outer peripheral edge of the pole plate is closely attached to the inner wall of the stator housing.

[0013] Further, an avoidance notch corresponding to the pin mounting position is provided at the rear edge of the stator housing.

[0014] Further, the cross-section of the limiting step is a trapezoidal structure, and the outer diameter of its front end is larger than that of the rear end.

[0015] Further, the U-shaped notches are evenly distributed on the annular surface at the rear end of the rotor body, are axially arranged and extend to the front side of the limiting step.

[0016] Further, a guiding head is provided at the front end of the stator body, and a guiding frame is provided around the guiding head.

[0017] Further, a bearing mounting ring is provided at the rear end of the stator body, a positioning convex block is provided at the bottom of the bearing mounting ring, and a positioning notch cooperating with the positioning convex block is provided at the bottom of the inner wall on the front side of the socket.

[0018] Further, a U-shaped buckle is provided at the upper end of the pin, and the U-shaped buckle is connected to the pins one by one;

[0019] The lower end of the pin extends into the insertion interface of the socket.

[0020] Further, a snap ring is provided at the rear edge of the housing, a ring groove cooperating with the snap ring is provided at the front edge of the socket, and the snap ring is inserted into the ring groove and connected to each other.

[0021] After adopting the above technical solutions, the beneficial effects of the present invention are as follows:

[0022] (1) The present invention adopts an integrated stator housing, simplifies the structure of the entire stator assembly, reduces the assembly difficulty of the stator assembly, and improves the processing efficiency;

[0023] (2) By providing the annular groove and the U-shaped notch, the bearing can be directly installed and fixed in the annular groove, which is convenient for installation, does not require additional installation of other fixing parts, reduces the use cost, and can avoid the situation of bearing shaking caused by the displacement or falling off of the fixing parts after long-term use, ensuring the normal use of the stepping motor;

[0024] (3) Since the pins of the present invention are arranged on the rear side wall of the coil groove located at the rear, the distance from the pins is shortened, and the pins are directly and rigidly connected through the insertion pins, eliminating the installation of wires. Changing the two connection points into one connection point reduces the assembly difficulty, reduces the occurrence of faults, and ensures the normal use of the stepper motor. Description of the Drawings

[0025] The present invention will be further described below in conjunction with the drawings and embodiments.

[0026] Figure 1 is the structural diagram of the stepper motor of the present invention;

[0027] Figure 2 is the axial sectional view of the stepper motor of the present invention;

[0028] Figure 3 is the structural diagram of the stepper motor of the present invention when the housing is not installed;

[0029] Figure 4 is the structural diagram of the stator assembly of the stepper motor of the present invention;

[0030] Figure 5 is the structural diagram of the stator body of the stepper motor of the present invention;

[0031] Figure 6 is the structural diagram of the stator housing of the stepper motor of the present invention;

[0032] Figure 7 is the structural diagram of the rotor assembly of the stepper motor of the present invention;

[0033] Figure 8 is the structural diagram of the housing of the stepper motor of the present invention;

[0034] Figure 9 is the structural diagram of the socket of the stepper motor of the present invention;

[0035] In the figure: housing 1, snap ring 11, socket 2, insertion pin 21, positioning notch 22, U-shaped buckle 23, insertion interface 24, annular groove 25, stator assembly 3, stator body 31, stator housing 32, coil groove 33, pin 34, wiring seat 35, installation groove 36, wire passing groove 37, avoidance notch 38, guiding head 39, guiding frame 310, bearing installation ring 311, positioning convex block 312, retaining ring 313, rotor assembly 4, rotor body 41, transmission lead screw 42, annular groove 43, limiting step 44, U-shaped notch 45, annular magnet 46, bearing 5, tapered head 6, spring 7. Detailed Embodiments

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0038] As Figures 1-9 shown, a stepper motor includes a housing 1, a socket 2 installed at the rear end of the housing 1, and a stator assembly 3 and a rotor assembly 4 disposed within the housing 1. The stator assembly 3 includes a stator body 31 and an integral stator housing 32 sleeved outside the stator body 31. Two coil slots 33 for placing coils are arranged in parallel on the outer ring surface of the stator body 31. At the top of the rear side wall of the rear coil slot 33, there is a pin 34 connected to the coil. The rotor assembly 4 includes a rotor body 41 and a transmission lead screw 42 threadedly engaged in the shaft hole of the rotor body 41. An annular groove 43 is provided on the outer ring surface of the rotor body 41. A limiting step 44 is provided at the rear side of the annular groove 43. At least two U-shaped notches 45 are provided at the rear end of the rotor body 41. A bearing 5 with an outer ring connected to the stator body 31 is installed in the annular groove 43. In the socket 2, there is a pin 21 rigidly connected to the pin 34 at the upper end.

[0039] Specifically, in order for the stator assembly 3 to drive the rotor assembly 4, an annular magnet 46 is provided on the outer ring surface of the rotor body 41 in front of the annular groove 43. The rotation of the annular magnet 46 drives the rotation of the rotor body 41. In order to ensure the firm connection between the annular magnet 46 and the rotor body 41, and thus achieve the synchronous rotation of the two, the annular magnet 46 is integrally injection-molded on the outer ring surface of the rotor body 41.

[0040] In order to be able to convert the rotation of the rotor body 41 into the linear motion of the transmission lead screw 42, the transmission lead screw 42 is installed in the shaft hole of the rotor body 41.

[0041] Specifically, an internal thread is provided in the shaft hole, and an external thread is provided on the transmission lead screw 42. The external thread meshes with the internal thread. When the rotor body 41 rotates, through the meshing of the internal thread hole and the external thread, it can drive the transmission lead screw 42 to move in its axial direction, thereby converting the angular displacement of the rotor body 41 into the linear displacement of the transmission lead screw 42.

[0042] Preferably, for the convenience of installing the pin 34, a wiring seat 35 is provided at the top of the rear side wall of the coil slot 33 located at the rear side. An installation slot 36 is provided on the wiring seat 35, and the pin 34 is installed in the installation slot 36.

[0043] Specifically, since there are two coils and both ends of each coil need to be separately connected to a pin 34, four installation slots 36 are arranged in parallel on the connection seat, and the pins 34 also include four, which are correspondingly arranged in the four installation slots 36.

[0044] The coil needs to be powered to generate an electromagnetic field so as to realize the rotation of the rotor inside the stator assembly 3. In order to facilitate the connection between the coil located at the front side and the pin 34 and avoid the coil contacting the stator housing 32 when bypassing the side wall between the two coil slots 33, a wire passing slot 37 is provided at the top of the side wall between the two coil slots 33.

[0045] Preferably, there are two wire passing slots 37, which facilitate the two ends of the coil located at the front side to separately pass through one wire passing slot 37 and be connected to the corresponding pin 34.

[0046] In order to simplify the installation difficulty of the stator assembly 3, plates are provided inside the side walls on both sides of each coil slot 33 and are integrally injection-molded with the stator body 31, and the outer peripheral edge of the plate closely adheres to the inner wall of the stator housing 32.

[0047] Specifically, the plates are arranged inside the side walls of the coil slots 33 by overmolding and are of an integrally injection-molded structure with the stator body 31.

[0048] An arcuate notch corresponding to the wire passing slot 37 and the wiring seat 35 is provided at the top of each plate, and the rest of its outer peripheral edge except the arcuate notch is exposed from the stator body 31 and directly adheres to the inner wall of the stator housing 32 when the stator housing 32 is sleeved outside the coil slot 33, making the stator housing 32 a magnetic conductive ring.

[0049] In order to prevent the connection between the insertion pin 21 and the pin 34 from being connected to the stator housing 32, an avoidance notch 38 corresponding to the installation position of the pin 34 is provided at the rear side edge of the stator housing 32.

[0050] Preferably, the avoidance notch 38 is of a U-shaped structure and its width corresponds to the width of the wiring seat 35.

[0051] Since the limiting step 44 functions to fix and limit the bearing 5, the outer diameter of the limiting step 44 is greater than the inner diameter of the bearing 5. In order to facilitate the installation of the bearing 5, the cross section of the limiting step 44 is of a trapezoidal structure and its front outer diameter is greater than the rear outer diameter.

[0052] The outer diameter of the rear end of the limiting step 44 is smaller than the inner diameter of the bearing 5, which can facilitate the installation of the bearing 5, while the outer diameter of the front end of the limiting step 44 is larger than the inner diameter of the bearing 5, which can play a good role in fixing and limiting the bearing 5. The outer ring surface of the limiting step 44 is a slope surface, and its outer diameter gradually increases from the back to the front, which can further increase the smoothness of the installation process of the bearing 5.

[0053] In order to facilitate the installation of the bearing 5 into the annular groove 43 from the rear end of the rotor body 41 , the U-shaped notches 45 are evenly distributed on the annular surface at the rear end of the rotor body 41 , and are axially arranged and extend to the front side of the limiting step 44 .

[0054] The rotor body 41 is an injection molded part with a certain degree of elasticity. When installing the bearing 5, it is installed from the rear end of the rotor body 41 and moved forward. When the bearing 5 moves to the limiting step 44, it squeezes the rotor body 41, thereby compressing the U-shaped notch 45. At this time, the bearing 5 can pass through the limiting step 44 and enter the annular groove 43. The rear end of the rotor body 41 returns to its original state, and the limiting step 44 is used to fix the bearing 5 in the annular groove 43.

[0055] In order to facilitate the installation of the stator housing 32 , a guide head 39 is provided at the front end of the stator body 31 , and a guide frame 310 is provided on the periphery of the guide head 39 .

[0056] Specifically, the guide head 39 and the guide frame 310 are coaxially arranged with the stator body 31. When the stator housing 32 is installed, it is inserted from the front end of the stator body 31. The guide head 39 and the guide frame 310 are successively inserted into the stator housing 32 and pass out from the through hole at the center of the front end of the stator housing 32, and the stator housing 32 is sleeved on the outside of the two coils and the side walls on both sides.

[0057] In addition, a cone head 6 is installed at the front end of the guide head 39, and a spring 7 which is sleeved on the guide head 39 is arranged inside the cone head 6.

[0058] In order to facilitate the connection between the outer ring of the bearing 5 and the stator body 31, a bearing mounting ring 311 is provided at the rear end of the stator body 31, a positioning protrusion 312 is provided at the bottom of the bearing mounting ring 311, and a positioning notch 22 cooperating with the positioning protrusion 312 is provided at the bottom of the front inner wall of the socket 2.

[0059] The inner ring of the bearing 5 is fixed to the outer ring surface of the annular groove 43 , and the outer ring is fixed to the inner ring surface of the bearing mounting ring 311 , so that the rotor assembly 4 can rotate in the stator assembly 3 .

[0060] The arrangement of the positioning protrusion 312 and the positioning notch 22 allows the socket 2 to be sleeved outside the bearing mounting ring 311 when the socket 2 is matched with the stator body 31, and the positioning protrusion is inserted into the positioning notch 22 312 to prevent the socket 2 from rotating and avoid the pin 21 from separating from the pin 34.

[0061] The stator housing 32 is sleeved into the front end of the stator body 31 and installed outside the two coil slots 33 and the side walls of the coil slots 33. In order to facilitate the positioning of its rear end, a retaining ring 313 is provided at the rear side of the coil slot 33 at the rear side. The outer diameter of the retaining ring 313 is greater than the outer diameter of the side wall of the coil slot 33 and greater than the inner diameter of the front side of the socket 2. The retaining ring 313 can position both the rear end of the stator housing 32 and the front end of the socket 2 at the same time.

[0062] In order to ensure the stability of the connection between the pins 34 and the pins 21, a U-shaped buckle 23 is provided at the upper end of the pin 21, and the U-shaped buckle 23 is connected to the pin 34 in one-to-one correspondence.

[0063] Specifically, there are four pins 21, which are arranged side by side. Each pin 34 passes through the U-shaped hole in the middle of its corresponding U-shaped buckle 23, and the pin 34 is welded to the U-shaped buckle 23 with solder, thereby preventing the disconnection between the pin 34 and the pin 21 and ensuring the firmness of the connection between the two.

[0064] In order to facilitate the connection between the pin 21 and an external power source to supply power to the coil, the lower end of the pin 21 extends into the insertion interface 24 of the socket 2.

[0065] Specifically, the pin 21 is injection-molded in the socket 2, and the insertion interface 24 is located at the rear end of the socket 2 and opens downward.

[0066] When the housing 1 of the existing stepper motor is connected to the socket 2, the end of the housing 1 is sleeved on the end of the socket 2, and then rivets are driven from the outside of the housing 1 to fix the two. The connection process is relatively cumbersome, and the rivets affect the aesthetics of the entire stepper motor. In order to simplify the connection between the housing 1 and the socket 2, a snap ring 11 is provided at the rear edge of the housing 1, and a ring groove 25 that cooperates with the snap ring 11 is provided at the front edge of the socket 2. The snap ring 11 is inserted into the ring groove 25 and connected to each other.

[0067] After the snap ring 11 is snapped into the ring groove 25, ultrasonic welding is used to weld the end of the snap ring 11 to the inside of the card slot, so that the welding surface is inside. While ensuring the stable connection between the housing 1 and the socket 2, the aesthetics of the entire stepper motor is increased.

[0068] In the present invention, the pins 34 of the two coils are both arranged at the top of the rear side wall of the coil slot 33 on the right side, which can shorten the distance between the pins 34 and the pins 21, so that the pins 21 and the pins 34 can be directly and rigidly connected without the need for structures such as wires, simplifying the installation steps and reducing the connection points, thereby reducing the probability of failure. And in cooperation with the setting of the position of the pins 34, the stator housing 32 of the present invention is integrally formed, further simplifying the structure of the stator assembly 3, making the installation more convenient and improving the processing efficiency. In addition, through the setting of the annular groove 43, the limiting step 44 and the U-shaped notch 45, the bearing 5 can be directly fixed on the rotor body 41 without the need to additionally install fixing parts, simplifying the structure and installation steps of the rotor assembly 4 and further improving the processing efficiency.

[0069] Inspired by the above ideal embodiments of the present invention, through the above description, relevant workers can completely make various changes and modifications within the scope not deviating from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A stepper motor, characterized in that, it includes a housing (1) and a socket (2) installed at the rear end of the housing (1), as well as a stator assembly (3) and a rotor assembly (4) arranged inside the housing (1), wherein, the stator assembly (3) includes a stator main body (31), and an integral stator housing (32) sleeved outside the stator main body (31). Two coil slots (33) for placing coils are arranged in parallel on the outer ring surface of the stator main body (31). A pin (34) connected to the coil is arranged at the top of the rear side wall of the coil slot (33) located at the rear; the rotor assembly (4) includes a rotor main body (41), and a transmission lead screw (42) threadedly engaged in the shaft hole of the rotor main body (41). An annular groove (43) is arranged on the outer ring surface of the rotor main body (41). A limiting step (44) is arranged at the rear side of the annular groove (43). At least two U-shaped notches (45) are arranged at the rear end of the rotor main body (41). A bearing (5) with an outer ring connected to the stator main body (31) is installed in the annular groove (43); a pin (21) with an upper end rigidly connected to the pin (34) is arranged in the socket (2); the cross-section of the limiting step (44) is a trapezoidal structure, and its front outer diameter is larger than the rear outer diameter; the U-shaped notches (45) are evenly distributed on the annular surface at the rear end of the rotor main body (41), and are arranged axially and extend to the front side of the limiting step (44); the outer diameter of the limiting step (44) is larger than the inner diameter of the bearing (5); the rotor main body (41) is an injection molded part; a U-shaped buckle (23) is arranged at the upper end of the pin (21), and the U-shaped buckle (23) is connected to the pin (34) in one-to-one correspondence.

2. The stepper motor according to claim 1, characterized in that, a wire passing groove (37) is arranged at the top of the side wall between the two coil slots (33).

3. The stepper motor according to claim 1, characterized in that, plates integrally injection molded with the stator main body (31) are arranged inside the side walls on both sides of each coil slot (33), and the outer peripheral edge of the plate closely adheres to the inner wall of the stator housing (32).

4. The stepper motor according to claim 1, characterized in that, an avoidance notch (38) corresponding to the installation position of the pin (34) is arranged at the rear side edge of the stator housing (32).

5. The stepper motor according to claim 1, characterized in that, a guiding head (39) is arranged at the front end of the stator main body (31), and a guiding frame (310) is arranged around the guiding head (39).

6. The stepper motor according to claim 1, characterized in that, a bearing installation ring (311) is arranged at the rear end of the stator main body (31). A positioning convex block (312) is arranged at the bottom of the bearing installation ring (311). A positioning notch (22) cooperating with the positioning convex block (312) is arranged at the bottom of the inner wall on the front side of the socket (2).

7. The stepper motor according to claim 1, characterized in that, The lower end of the pin (21) extends into the insertion interface (24) of the socket (2).

8. The stepping motor according to claim 1, characterized in that a snap ring (11) is provided at the rear end edge of the housing (1), a ring groove (25) that mates with the snap ring (11) is provided at the front side edge of the socket (2), and the snap ring (11) is inserted into the ring groove (25) and connected to each other.

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