A permanent magnet reduction motor and its assembly method

Abstract

The present invention discloses a permanent magnet reduction motor and an assembly method thereof, comprising a housing assembly, a cover assembly, a rotor assembly, a stator assembly, an output shaft assembly, two primary gears, and two secondary gears. The rotor assembly comprises a magnetic ring and rotor shaft teeth located at one end of the magnetic ring. The rotor shaft teeth, primary gear, secondary gear, and output shaft assembly are sequentially meshed and driven. A chamfer C is provided on the tooth profile end face of the rotor shaft teeth to enable the two primary gears to rotate a certain angle and then mesh with the rotor shaft teeth simultaneously. The present invention utilizes the characteristic that the backlash of the final gear causes the driven wheel of the primary gear to rotate proportionally in the circumferential direction before meshing with the driving wheel of the primary gear. By providing the chamfer C, the primary gear is allowed to rotate circumferentially past the tooth tip of the rotor shaft teeth to reach a meshing state, thus avoiding tooth damage. This assembly method can improve the flexibility of gear installation, thereby widening the reduction ratio of the reduction gear.

Description

Technical Field

[0001] The present invention relates to the technical field of motor design, and in particular to a permanent magnet reduction motor and an assembly method thereof. Background Art

[0002] Motors are widely used in household appliances. Currently there is a permanent magnet reduction motor, such as Figure 1 As shown, it primarily comprises a housing assembly, a rotor assembly, a stator assembly, a gear bracket, two primary gears, two secondary gears, an output shaft assembly, and a cover assembly. The output shaft assembly includes an output gear and an output shaft, which coincide with the axis of the rotor assembly. The two primary gears and two secondary gears are spur gears with different pitch diameters and are integrated along the axis to form a double-linked gear. The two primary gears are mounted on first gear shafts that are point-symmetrical with each other about the rotor assembly's center of rotation, while the two secondary gears are mounted on second gear shafts that are point-symmetrical with each other about the rotor assembly's center of rotation. The rotor assembly simultaneously meshes with the two primary gears, with one primary gear meshing with one secondary gear to form the first gear train A, and the other primary gear meshing with the other secondary gear to form the second gear train B. Finally, the two secondary gears simultaneously mesh with the output gear of the output shaft assembly, outputting torque through the output shaft.

[0003] The existing production and assembly method of this structural motor is to first install the stator assembly into the housing assembly, and then assemble the two primary gears, the gear bracket, and the two secondary gears. Since the side clearance of the primary gear is small in the design of the reduction gear system, when the primary gear is first engaged with the rotor assembly, the circumferential angle of the primary gear is fixed, and the angle cannot be flexibly adjusted when the final gear is subsequently installed. In order to ensure that the first gear system A, the second gear B and the output gear of the output shaft assembly are engaged without tooth misalignment, the tooth shape of the shaft teeth of the primary gear and the tooth shape of the wheel blade are kept at a fixed angle in the circumferential direction when the motor mechanism is designed, and two first process holes are designed on the wheel blade of the primary gear with the center of symmetry relative to the axis of the primary gear; similarly, the tooth shape of the shaft teeth of the secondary gear and the wheel blade are kept at a fixed angle in the circumferential direction, and two first process holes are designed on the wheel blade of the primary gear with the center of symmetry relative to the axis of the primary gear; similarly, the tooth shape of the shaft teeth of the secondary gear and the wheel blade are kept at a fixed angle in the circumferential direction when the motor mechanism is designed. The tooth profile maintains a fixed angle in the circumferential direction, and two second process holes are designed on the wheel plate of the secondary gear with the center of symmetry relative to the axis of the secondary gear. The shaft teeth of the rotor assembly must be an even number of teeth, and the output gear must be an even number of teeth; when the two first gears and the two secondary gears are assembled to the first gear shaft and the second gear shaft, they must be assembled at a fixed angle, that is, the tooth profiles of the two first gears and the angles of the first process holes must be axisymmetric relative to the rotation center of the rotor assembly, and the tooth profiles of the two secondary gears and the angles of the second process holes must be axisymmetric relative to the rotation center of the rotor assembly.

[0004] This will result in:

[0005] 1. The reduction ratio design range of the reduction gear is narrow;

[0006] 2. The assembly is difficult, resulting in low assembly efficiency.

[0007] 3. The asymmetry of the gears makes it easier to assemble, resulting in the first gear system A and the second gear system B not meshing synchronously during the motor rotation gear meshing process, resulting in large mechanical losses during the gear transmission process, reduced motor output torque, and even the inability to assemble the output shaft assembly during the assembly process. Summary of the Invention

[0008] In order to solve the technical problems in the prior art that the motor needs to be assembled with a primary gear first, the final gear cannot flexibly adjust the angle, and the installation position, number of teeth and shaft tooth angle of each gear need to be precisely designed, resulting in great difficulty in assembly and a narrow design range of the reduction ratio of the reduction gear, the present invention provides a permanent magnet reduction motor and an assembly method thereof to solve the above problems.

[0009] The present invention proposes a permanent magnet reduction motor, including a housing assembly, a cover assembly, a rotor assembly, a stator assembly, an output shaft assembly, two primary gears and two secondary gears. The rotor assembly includes a magnetic ring and rotor shaft teeth located at one end of the magnetic ring. The rotor shaft teeth, the primary gear, the secondary gear and the output shaft assembly are meshed and transmitted in sequence. A chamfer C is provided on the tooth end face of the rotor shaft teeth so that the two primary gears can simultaneously mesh with the rotor shaft teeth after rotating a certain angle.

[0010] Furthermore, the chamfer angle C is between 10° and 15°.

[0011] The present invention also provides an assembly method of the above-mentioned permanent magnet reduction motor, comprising the following steps:

[0012] S1: Prepare the housing assembly, cover assembly, rotor assembly, stator assembly and output shaft assembly respectively.

[0013] S2: Assemble the primary gear, secondary gear and output shaft assembly on the stator assembly in sequence so that the two secondary gears are engaged with the output shaft assembly; assemble the rotor assembly in the housing assembly.

[0014] S3: Install the stator assembly assembled in step S2 into the housing assembly so that the two primary gears are meshed with the rotor shaft teeth.

[0015] S4: Fix the cover assembly and the shell assembly.

[0016] Furthermore, the shell assembly includes a shell and a core shaft, the shell includes a bottom wall and an annular side wall, annular grooves are provided at both axial ends of the core shaft, and one end of the core shaft is riveted and fixed in the center hole of the bottom wall.

[0017] Furthermore, the assembly steps of the shell assembly are: first, the core shaft is inserted into the center hole, and the annular groove is located in the center hole, and then the annular rivet head of the riveting mold is used to rivet annular rivet marks on the lower surface of the bottom wall of the shell to make the center hole shrink and hold the annular groove tightly.

[0018] Furthermore, the cover plate assembly includes a bearing and a cover plate, the output shaft is cooperatively connected to the bearing, a flanging hole is provided at the center of the cover plate, the bearing is installed in the flanging hole, and one axial end of the bearing is provided with a limiting structure that abuts against the end face of the flanging hole.

[0019] Furthermore, the outer edge of the cover plate is provided with a plurality of concave steps. The cover plate is located on the end of the annular side wall away from the bottom wall and abuts against the inner wall of the annular side wall. The annular side wall is punched and bent in the axial direction to form rivet feet corresponding to the concave steps one by one.

[0020] Furthermore, it also includes a gear bracket placed at one end of the stator assembly, the wheel of the first-stage gear is axially limited between the gear bracket and the stator assembly, and the wheel of the second-stage gear is axially limited between the gear bracket and the output shaft assembly.

[0021] Furthermore, the stator assembly includes a coil assembly and a fixed plate assembly located at one axial end of the coil assembly, and the end surface of the fixed plate assembly is provided with a first gear shaft for two primary gears to pass through and a second gear shaft for two secondary gears to pass through, and the gear bracket has a semicircular boss that cooperates with the outer circumferential surface of the second gear shaft.

[0022] Furthermore, the coil assembly includes an upper frame, a middle plate and a lower frame that are overlapped with each other. The upper frame and the lower frame have multiple groups of positioning columns and positioning holes that cooperate with each other. Each group of positioning columns and positioning holes adopts interference fit, and the interference fit amount is 0.005~0.02mm.

[0023] The beneficial effects of the present invention are:

[0024] (1) The permanent magnet reduction motor and its assembly method described in the present invention provide a chamfer C on the tooth profile end face of the rotor shaft teeth. When the final gear is installed first, the side clearance of the final gear will cause the driven wheel of the primary gear to rotate proportionally in the circumferential direction before it is meshed with the driving wheel of the primary gear. The presence of the chamfer C can enable the primary gear to rotate circumferentially over the tooth tip of the rotor shaft teeth to reach the meshing state, avoiding tooth profile damage. This assembly method can improve the flexibility of gear installation, thereby widening the reduction ratio of the reduction gear.

[0025] (2) The permanent magnet reduction motor and the assembly method thereof described in the present invention utilize the coordination of positioning posts and positioning holes to assemble the stator assembly, thereby improving the assembly accuracy of the stator assembly.

[0026] (3) The permanent magnet reduction motor and its assembly method described in the present invention provide annular grooves at both ends of the core shaft, which not only improves the connection strength between the housing and the core shaft, but also prevents mistakes and improves installation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below with reference to the accompanying drawings and examples.

[0028] Figure 1 This is the structural diagram of the permanent magnet reduction motor after assembly in the existing assembly sequence;

[0029] Figure 2 is an exploded view of the permanent magnet reduction motor of the present invention;

[0030] Figure 3 is an exploded view of the housing assembly of the present invention;

[0031] Figure 4 This is a riveted assembly diagram of the first gear shaft, the second gear shaft and the fixing plate in the present invention;

[0032] Figure 5 Schematic diagram of the upper plate in the present invention;

[0033] Figure 6 is a schematic diagram of the fixed plate assembly of the present invention;

[0034] Figure 7 is an exploded view of the coil assembly of the present invention;

[0035] Figure 8 This is an overall diagram of the coil assembly of the present invention;

[0036] Figure 9 is a schematic diagram of the output shaft assembly of the present invention;

[0037] Figure 10 This is a front view of the cover assembly of the present invention;

[0038] Figure 11 yes Figure 10 DD sectional view;

[0039] Figure 12 is a three-dimensional diagram of the gear bracket in the present invention;

[0040] Figure 13 is a schematic diagram of the gear bracket after assembly in the assembly sequence of the present invention;

[0041] Figure 14 is a schematic diagram of the output shaft assembly after assembly in the assembly sequence of the present invention;

[0042] Figure 15 is a schematic diagram of the cover plate assembly after assembly in the assembly sequence of the present invention;

[0043] Figure 16 It is a cross-sectional view of the whole machine of the present invention;

[0044] Figure 17 This is a schematic diagram of the cover plate after riveting in the assembly sequence of the present invention;

[0045] Figure 18 is a schematic diagram of the interior of the electrode in the assembly sequence of the present invention;

[0046] Figure 19 yes Figure 16 Enlarged view of point a in the middle;

[0047] Figure 20 It is a cross-sectional view of the rotor assembly in the present invention.

[0048] In the figure, 1, housing assembly, 11, housing, 111, annular side wall, 112, lower pole claw, 113, side opening, 114, center hole, 115, bottom wall, 116, first incision, 117, second incision, 118, third incision, 119, rivet foot, 120, annular rivet mark, 12, core shaft, 121, annular groove, 2, reed, 3, rotor assembly, 31, rotor shaft teeth, 311, chamfer, 32, magnetic ring, 4, stator assembly, 41, fixing plate assembly, 411, fixing plate, 4111, second positioning convex hull, 4112, second positioning hole, 4113, Fourth process hole, 4114, sixth positioning hole, 4115, stator shoulder, 4116, first shaft hole, 4117, second shaft hole, 412, first gear shaft, 413, upper plate, 4131, first positioning convex bump, 4132, first positioning hole, 4133, third process hole, 4134, upper pole claw, 414, second gear shaft, 42, coil assembly, 421, upper frame, 4211, first wire groove, 4212, third positioning column, 4213, lower limit column, 4214, first positioning column, 4215, second positioning column, 4216, second protrusion, 4 217, guide pin seat, 4218, stopper, 4219, guide pin hole, 422, middle plate, 4221, third positioning convex bump, 4222, third positioning hole, 4223, fifth process hole, 4224, middle claw, 4225, base plate, 4226, notch, 423, lower frame, 4231, limit block, 4232, first protrusion, 4233, fifth positioning hole, 4234, fourth positioning hole, 4235, second wire trough, 424, outlet box, 4241, buckle, 425, guide pin, 426, frame assembly, 427, enameled wire, 5, first gear , 51, the first process hole, 6, the gear bracket, 61, the fourth positioning column, 62, the semicircular ring boss, 63, the sinking hole, 64, the gear shoulder frame, 65, the upper sinking hole, 7, the secondary gear, 71, the second process hole, 8, the output shaft assembly, 81, the output shaft, 82, the output gear, 83, the shaft head, 9, the cover assembly, 91, the bearing, 911, the limiting structure, 92, the cover, 921, the flanging hole, 922, the third shaft hole, 923, the fourth shaft hole, 924, the lateral protrusion, 925, the limiting convex edge, 926, the mounting plate, 927, the concave step, 928, the mounting hole. DETAILED DESCRIPTION

[0049] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0050] Example 1

[0051] like Figure 2 、 Figure 16 and Figure 20 As shown, a permanent magnet reduction motor includes a housing assembly 1, a cover assembly 9, a rotor assembly 3, a stator assembly 4, an output shaft assembly 8, two primary gears 5 and two secondary gears 7. The rotor assembly 3 includes a magnetic ring 32 and a rotor shaft tooth 31 located at one end of the magnetic ring 32. The rotor shaft tooth 31, the primary gear 5, the secondary gear 7 and the output shaft assembly 8 are meshed and transmitted in sequence. A chamfer 311C is provided on the tooth end surface of the rotor shaft tooth 31 so that the two primary gears 5 can rotate a certain angle and mesh with the rotor shaft tooth 31 at the same time.

[0052] The positional relationship of the various components after assembly in the present invention is the same as the motor structure in the background technology. The reduction gears (i.e., the first-stage gear 5 and the second-stage gear 7) of the reduction gear system of the permanent magnet reduction motor are mostly plastic injection molded. Taking into account the processing dimensional error of injection molding and the slight dimensional change of the plastic itself caused by the influence of the use environment, the gear side clearance of the reduction gear meshing will be increased accordingly when designing the reduction gear system, generally 0.03-0.05mm; the existence of this gear side clearance enables the gear to have a certain angle of rotation in the circumferential direction; because of the design of the reduction ratio of the reduction gear system, the final gear side clearance will cause the driven wheel of the primary gear to rotate proportionally in the circumferential direction before it engages with the driving wheel of the primary gear.

[0053] In the motor structure of the present invention, the wheel blades of the first-stage gear 5 mesh with the rotor shaft teeth 31 to form a primary gear, and the wheel blades of the second-stage gear 7 mesh with the output shaft assembly 8 to form a final gear.

[0054] When the secondary gear 7 is assembled with the output shaft assembly 8, and the primary gear 5 is matched with the rotor shaft teeth 31, the rotor shaft teeth 31 is the driving wheel of the primary gear, and the wheel piece of the primary gear 5 is the driven wheel of the primary gear; due to the existence of the side clearance of the final transmission gear, when the wheel pieces of the two primary gears 5 are engaged with the rotor shaft teeth 31, the wheel pieces of the two primary gears 5 can rotate at a large angle in the circumferential direction, and usually need to pass over one or more shaft teeth of the rotor shaft teeth 31. However, the tooth end surface of the rotor shaft teeth 31 in the prior art does not have a chamfer 311. The wheel piece of the primary gear 5 and the rotor shaft teeth 31 will interfere with the tooth end, resulting in the primary gear 5 being unable to rotate to the meshing position. The present invention provides a clearance space for the wheel piece of the primary gear 5 by setting the chamfer 311C. As long as the angle of the chamfer 311C is reasonably designed (the size of the chamfer 311C is preferably 10°~15°), the wheel piece of the primary gear 5 can be exactly engaged with the rotor shaft teeth 31 without causing tooth disengagement, thereby providing the possibility of adjusting the installation order of the motor in the present invention.

[0055] The present invention provides an assembly method for the above-mentioned permanent magnet reduction motor, which comprises the following steps:

[0056] S1: Prepare the housing assembly 1, the cover assembly 9, the rotor assembly 3, the stator assembly 4 and the output shaft assembly 8 respectively.

[0057] S2: Assemble the primary gear 5 , the secondary gear 7 and the output shaft assembly 8 on the stator assembly 4 in sequence, so that the two secondary gears 7 are meshed with the output shaft assembly 8 ; the rotor assembly 3 is assembled in the housing assembly 1 .

[0058] S3: Install the stator assembly 4 assembled in step S2 into the housing assembly 1 so that the two primary gears 5 are meshed with the rotor shaft teeth 31 .

[0059] S4: Fix the cover assembly 9 to the housing assembly 1.

[0060] Unlike the prior art, the present invention first assembles the reduction gear train and the output shaft assembly 8 with the stator assembly 4, thereby assembling the final gear of the reduction gear train first, and then installing the stator assembly 4 into the housing assembly 1 with the rotor assembly 3, that is, the primary gear of the reduction gear train is assembled later. The first-stage gear 5 has a certain circumferential rotation space when assembled with the rotor shaft teeth 31, so the first-stage gear 5 and the second-stage gear 7 can be assembled at any angle in the circumferential direction. The two first-stage gears 5 and the two second-stage gears 7 do not need to be arranged symmetrically relative to the axis of the rotor assembly 3, and there is no need to set process holes, so there will be no incomplete assembly phenomenon, and the first gear train A and the second gear train B will not have the phenomenon of meshing out of sync.

[0061] In addition, when designing the reduction gear, the gear can be designed with an odd number of teeth or an even number of teeth, which increases the design range of the reduction ratio; the shaft teeth and the wheel pieces do not need to form a fixed angle, so when the gear is injected, the design and installation difficulty of the injection mold are greatly reduced.

[0062] To facilitate the assembly of the reduction gear, the present invention also includes a gear bracket 6 placed at one end of the stator assembly 4, the wheel blade of the first-stage gear 5 is axially limited between the gear bracket 6 and the stator assembly 4, and the wheel blade of the second-stage gear 7 is axially limited between the gear bracket 6 and the output shaft assembly 8.

[0063] The structure of each component and its preparation method are described in detail below:

[0064] (1) Preparation of housing assembly 1

[0065] like Figure 3 and Figure 8As shown, the housing assembly 1 includes a housing 11 and a core shaft 12. The housing 11 includes a bottom wall 115 and an annular side wall 111. A center hole 114 is provided in the center of the bottom wall 115. Part of the material of the bottom wall 115 is bent toward the side of the annular side wall 111 on the periphery of the center hole 114 to form a lower pole claw 112 that cooperates with the stator assembly 4. One end of the core shaft 12 is riveted and fixed in the center hole 114 of the bottom wall 115, and the other end of the core shaft 12 is placed on the side of the annular side wall 111 of the housing 11. The annular side wall 111 has a side opening 113 for installing the outlet box 424.

[0066] (2) Preparation of output shaft assembly 8

[0067] like Figure 9 、 Figure 13 and Figure 16 As shown, the output shaft assembly 8 can have two structures, one with a friction mechanism and one without a friction mechanism. The output shaft assembly 8 with a friction mechanism is realized by a riveting process, while the output shaft assembly 8 without a friction mechanism can be realized by a riveting process or an insert injection molding process. The output shaft assembly 8 of this embodiment is completed by an insert injection molding process and does not have a friction mechanism. Specifically, the output shaft assembly 8 includes a shaft head 83, an output gear 82, and an output shaft 81, which are connected in sequence along the axial direction. The center of the gear bracket 6 has an upper countersunk hole 65 for inserting the shaft head 83. The output gear 82 meshes with the teeth of the secondary gear 7. The output shaft 81 passes through the cover assembly 9 to connect to the external device.

[0068] (3) Preparation of stator assembly 4

[0069] The stator assembly 4 includes a coil assembly 42 and a fixed plate assembly 41 located at one axial end of the coil assembly 42. The end surface of the fixed plate assembly 41 is provided with a first gear shaft 412, through which the two primary gears 5 pass, and a second gear shaft 414, through which the two secondary gears 7 pass. The gear bracket 6 has a semi-circular boss 62 that mates with the outer circumference of the second gear shaft 414. The two semi-circular bosses 62 are arranged symmetrically about the upper countersunk hole 65. The center of the gear bracket 6 is located by the core shaft 12. The semi-circular boss 62 can determine the planar position of the gear bracket 6 and limit its rotation.

[0070] The fixed plate assembly 41 includes a fixed plate 411 and an upper electrode plate 413 that are stacked on each other. The specific steps for preparing the fixed plate assembly 41 are as follows:

[0071] a. The first gear shaft 412, the second gear shaft 414 and the fixing plate 411 are riveted together. Figure 4As shown: the two first gear shafts 412, the two second gear shafts 414 and the fixed plate 411 are riveted together using a riveting die, wherein one end of the two first gear shafts 412 is positioned with two first shaft holes 4116 of the fixed plate 411 that are symmetrical with respect to the center of the fixed plate 411, and the other end is placed on the side of the stator shoulder 4115 of the fixed plate 411. The stator shoulder 4115 is used to limit the cover plate assembly 9. When the cover plate assembly 9 is installed, the cover plate assembly 9 is fitted with the end surface of the stator shoulder 4115 (as shown in FIG. Figure 15 one end portion of the two second gear shafts 414 cooperates with two second shaft holes 4117 of the fixed plate 411 symmetrical with respect to the center of the fixed plate 411, and the other end portion is placed on the side of the stator shoulder 4115 of the fixed plate 411.

[0072] b. The upper plate 413 is overlapped with the fixed plate 411, as shown in FIG. Figure 5 、 Figure 6 As shown: the upper surface of the upper electrode plate 413 and the lower surface of the fixed plate 411 are overlapped with each other, and two first positioning convex bumps 4131 and first positioning holes 4132 are provided on the upper electrode plate 413. The two first positioning convex bumps 4131 and the two first positioning holes 4132 are arranged alternately and approximately in a circular array with the axis of the stator assembly 4 as the center. Two second positioning convex bumps 4111 and second positioning holes 4112 are provided on the fixed plate 411. The first positioning convex bump 4131 cooperates with the second positioning hole 4112, and the second positioning convex bump 4111 cooperates with the first positioning hole 4132, and both are transition fits, and the interference fit is preferably 0-0.02mm. The first positioning convex bump 4131 is fastened to the second positioning hole 4112, and the second positioning convex bump 4111 is fastened to the first positioning hole 4132 by expansion riveting the positioning convex bumps. After stacking and tightening the fixed plate assembly 41, there is no gap between the overlapping surfaces of the upper electrode plate 413 and the fixed plate 411. There is no noticeable deformation around the first positioning hole 4132 and the second positioning hole 4112. After the fixed plate assembly 41 was dropped from a height of 1 meter onto a concrete floor, the upper electrode plate 413 and the fixed plate 411 did not fall apart. Two third process holes 4133 are provided on the upper electrode plate 413, and two fourth process holes 4113 are provided on the fixed plate 411. After stacking, the third process holes 4133 and the fourth process holes 4113 overlap. The upper electrode plate 413 has an upper pole claw 4134 at its center, bent away from the fixed plate 411.

[0073] The coil assembly 42 is composed of a skeleton assembly 426, enameled wire 427, and an outlet box 424. The skeleton assembly 426 includes an upper skeleton 421, a middle plate, and a lower skeleton 423 that overlap each other. The upper skeleton 421 and the lower skeleton 423 have multiple sets of positioning posts and positioning holes that cooperate with each other. Each set of positioning posts and positioning holes adopts an interference fit, and the interference fit amount is 0.005 to 0.02 mm. The preparation steps of the skeleton assembly 426 are as follows: Figure 7 As shown:

[0074] a. The upper intermediate plate 422 is overlapped with the upper frame 421: the intermediate claws 4224 of the intermediate plate 422 are evenly spaced in the circumferential direction and are placed on the inner circumference of the upper frame 421. Two fifth process holes 4223 are symmetrically provided on the intermediate plate 422. Two lower limit posts 4213 are correspondingly provided on the lower end surface of the upper frame 421. The fifth process holes 4223 are assembled with the lower limit posts 4213.

[0075] b. The upper intermediate plate 422 and the lower intermediate plate 422 are stacked back to back: the base plates 4225 of the two intermediate plates 422 are stacked back to back, and each intermediate plate 422 has two third positioning protrusions 4221 and two third positioning holes 4222. The two third positioning protrusions 4221 of one intermediate plate 422 are placed in the two third positioning holes 4222 of the other intermediate plate 422. After stacking, the outer contours of the two intermediate plates 422 coincide, and the intermediate claws 4224 are rotated by an angle of 360 / 4P (P is the number of pole pairs of the motor).

[0076] c. The lower frame 423 is superimposed on the upper frame 421: the lower frame 423 is provided with a first protrusion 4232 and a stop block 4231 at a circumferentially symmetrical position. The protrusion protrudes radially from the outside of the middle plate 422. The middle plate 422 has a notch 4226 that is shaped like the stop block 4231. The first protrusion 4232 is provided with two fourth positioning holes 4234. The stop block 4231 is provided with a fifth positioning hole 4233. The upper frame 421 has a first positioning column 4214 that is suitable for inserting into the fifth positioning hole 4233 and a notch 4226 that is shaped like the stop block 4231. The second protrusion 4216 overlaps the upper and lower frames 4233, and is provided with two second positioning posts 4215 that mate with the fourth positioning holes 4234. The first positioning post 4214 and the fifth positioning hole 4233, as well as the second positioning post 4215 and the fourth positioning hole 4234, are both interference fits, with the interference margin generally being 0.005-0.02mm. Excessive interference margins can cause the upper and lower frames 423 to not overlap properly, creating a gap. Excessive interference margins can cause the upper and lower frames 423 to loosen, scatter during rotation, and cause vibration and noise in the motor. By creating an interference fit between the positioning posts and the positioning holes, the motor can be easily transferred to subsequent workstations without causing looseness, thereby reducing noise generated by the motor due to loose upper and lower frames 423. The intermediate pole claws 4224 of the lower intermediate pole plate 422, which are evenly spaced circumferentially, are positioned on the inner circumference of the lower frame 423 and mate with the lower pole claws 112.

[0077] d. Insert the pin 425 into the pin hole 4219 of the upper frame 421 and bend it: A pin seat 4217 is provided at the upper end of the upper frame 421, and a plurality of pin holes 4219 are provided on the pin seat 4217. Use a pin insertion machine to insert the pin 425 into the pin hole 4219 of the upper frame 421, and then use a bending tool to bend the pins 425 placed at both ends of the pin hole 4219 90 degrees, which are used for winding and welding the external power line respectively.

[0078] After the skeleton assembly 426 is prepared, the assembly steps of the coil assembly 42 are as follows: Figure 7 and Figure 8 As shown:

[0079] a. Winding: Use a fully automatic winding machine to wind the enameled wire 427 into the first wire slot 4211 of the upper frame 421 of the frame assembly 426 and the second wire slot 4235 of the lower frame 423. Two sets of windings are wound in each wire slot. The end of the enameled wire 427 is wound around the square pin 425 on the inner side of the upper frame 421.

[0080] b. Tinning: Use a fully automatic tinning machine to tin the part of the square needle 425 wrapped with the enameled wire 427. The tinning depth is required to be 1-2 turns without tinning.

[0081] c. Wire loosening: Use the fully automatic wire loosening tool to bend the tinned square pin 425 part toward the direction of the enameled wire 427 by 10-30 degrees, 20 degrees being the best, so that the enameled wire 427 between the winding and the square pin 425 is in a relaxed state, preventing this part of the enameled wire 427 from breaking due to thermal expansion and contraction.

[0082] d. Assembly of outlet box 424: The guide pin 425 passes through the guide pin slot of outlet box 424. Stoppers 4218 are provided on both sides of the guide pin seat 4217. Two symmetrically distributed buckles 4241 on outlet box 424 cooperate with the stoppers 4218 to position them.

[0083] e. Inspection: Use an automated test fixture equipped with an ohmmeter to perform a full resistance test on the coil windings to ensure there are no resistance deviations, open circuits, or short circuits. Use imaging to ensure that the enameled wire 427 wrapped around the first and second wire slots 4211 and 4235, as well as the square pin 425, is free of defects such as loose wires or extra wire ends.

[0084] (IV) Preparation of cover plate assembly 9

[0085] like Figure 10 and Figure 11As shown, the cover plate assembly 9 includes a bearing 91 and a cover plate 92. The output shaft 81 is connected to the bearing 91. A flange hole 921 is provided at the center of the cover plate 92. The bearing 91 is installed into the flange hole 921 from the back side of the flange hole 921 on the cover plate 92 and assembled in place. (0.01-0.03) g of lubricating grease is applied to the inner circumference of the bearing 91 to ensure uniform application.

[0086] After all components are prepared, the following describes the motor assembly steps in detail according to the assembly order:

[0087] (1) The reed 2 is fitted onto the core shaft 12 of the housing assembly 1, and the core shaft 12 is oiled: The reed 2 is located on the bottom wall 115 of the housing assembly 1. During installation, the reed 2 is fitted onto the core shaft 12, and the housing assembly 1 is placed into the oiling fixture. The automatic oiling machine automatically adds a predetermined amount of lubricating grease to the end of the core shaft 12, and the automatic oiling machine pushes the oiled housing assembly 1 to the next assembly process of the rotor assembly 3.

[0088] (2) Cleaning and assembly of the rotor assembly 3: The rotor assembly 3 consists of a magnetic ring 32 and rotor shaft teeth 31. The rotor shaft teeth 31 are formed inside the magnetic ring 32 by an inlay injection molding process. After the outer peripheral surface and end surface of the rotor assembly 3 are cleaned with a pressure-sensitive adhesive tape, the rotor assembly 3 is mounted along the center hole on the core shaft 12 that has been filled with oil, and the rotor shaft teeth 31 are assembled upward (i.e., toward the gear bracket 6).

[0089] (3) Assembly of the stator assembly 4 and detection of the inner diameter of the stator assembly 4: The coil assembly 42 is placed on the inner diameter gauge with air holes. During the placement process, there is no sense of friction between the inner circumference of the middle pole claw 4224 and the inner diameter gauge. Then the fixed plate assembly 41 is placed on the inner diameter gauge. During the placement process, there is no sense of friction between the inner circumference of the upper pole claw 4134 and the inner diameter gauge. At the same time, the upper pole claw 4134 is placed on the inner circumference of the upper frame 421. The two third positioning posts 4212 of the upper frame 421 are respectively inserted into the two fourth process holes 4113 and the third process hole 413. 3, so as to achieve circumferential fixation of the fixed plate assembly 41 and the coil assembly 42; at this time, the circumferential misalignment angle between the upper pole claw 4134 and the middle pole claw 4224 located on the inner circumference side of the upper frame 421 is 360 / 2P (P is the number of pole pairs of the motor); after the fixed plate assembly 41 and the coil assembly 42 are superimposed and assembled in place, air is blown outwards from the air holes on the inner diameter gauge to purge the inner diameter of the stator assembly 4, the air pressure is set to 0.04-0.06Mpa, and the purge time is set to 1s. After the purge is completed, the stator assembly 4 is removed from the inner diameter gauge and placed in the assembly line.

[0090] (4) Assembly of the first-stage gear 5: The first-stage gear 5 is a reduction gear. Two spur gears with different pitch diameters are integrated in the axial direction. The surface of the first-stage gear 5 is covered with lubricating grease by centralized oil mixing. The two first-stage gears 5 that have been oil-mixed are respectively placed on the corresponding first gear shaft 412. The wheel of the first-stage gear 5 (the gear with the larger diameter) is placed at the bottom and fits in place with the fixing plate 411.

[0091] (5) Assembly of gear bracket 6, such as Figure 12 、 Figure 13 As shown: the gear bracket 6 is injection molded, the inner circumference of the two semicircular bosses 62 of the gear bracket 6 is matched with the outer circumference of the two second gear shafts 414 for positioning, the surface of the fixing plate 411 has two sixth positioning holes 4114, and the two fourth positioning columns 61 of the gear bracket 6 are inserted into the two sixth positioning holes 4114 ( Figure 6 (shown) and fits snugly into place. The upper and lower end surfaces of the gear bracket 6 are coaxially defined with an upper countersunk hole 65 and a lower countersunk hole 63, respectively. The shaft head 83 is mounted in the upper countersunk hole 65, and the end of the core shaft 12 is inserted into the lower countersunk hole 63. The gear bracket 6 has a centrosymmetrical structure with the center of the lower countersunk hole 63 as its center of symmetry. The two gear shoulders 64 of the gear bracket 6 are used to limit the cover plate assembly 9 and have the same function as the stator shoulders 4115.

[0092] (6) Assembly of the secondary gear 7: The secondary gear 7 is a reduction gear, which is formed by integrating two spur gears with different pitch circles in the axial direction. The surface of the secondary gear 7 is covered with lubricating grease by centralized oil mixing. The two oil-mixed secondary gears 7 are respectively placed on the corresponding second gear shaft 414, and the wheel of the secondary gear 7 is installed at the bottom. The wheel of the secondary gear 7 and the shaft teeth of the primary gear 5 are meshed with each other.

[0093] (7) Output shaft assembly 8 is assembled, as shown Figure 13 、 Figure 14 As shown: the shaft head 83 of the output shaft assembly 8 is inserted into the upper countersunk hole 65, and the output gear 82 is simultaneously engaged with the shaft teeth of the secondary gear 7 in place.

[0094] (8) Assemble the cover plate assembly 9, as shown in Figure 15 As shown: the bearing 91 of the cover assembly 9 is placed on the outer peripheral side of the output shaft 81, the lateral protrusion 924 of the cover 92 faces the outlet box 424, the two first gear shafts 412 are respectively inserted into the third shaft holes 922 of the corresponding cover 92, and the two second gear shafts 414 are respectively inserted into the fourth shaft holes 923 of the corresponding cover 92.

[0095] (9) Assembly of complete machine, such as Figure 16As shown: the stator assembly 4 with the cover assembly 9 assembled in (8) is installed into the housing assembly 1 with the rotor assembly 3 assembled in (2), and the outlet box 424 is assembled with the side opening 113 of the housing 11; the coil assembly 42 is assembled to the bottom wall 115 of the housing 11 and fits in place, the wheels of the two first-stage gears 5 are meshed with the rotor shaft teeth 31, and the core shaft 12 is inserted into the sinking hole 63 of the gear bracket 6, as shown. Figure 3 and Figure 17 As shown, the outer periphery of the cover plate 92 is provided with two limiting flanges 925. The upper end surface of the housing 11 is provided with two first notches 116 that cooperate with the limiting flanges 925 for positioning. Two mounting plates 926 are symmetrically provided on the outer periphery of the cover plate 92, respectively cooperating with the second notches 117 and the third notches 118 of the housing 11 for positioning. The two mounting plates 926 are provided with mounting holes 928 for installation at the customer's site.

[0096] (10) Cover plate 92 is riveted, as shown in FIG. Figure 17 As shown: a plurality of concave steps 927 are provided on the outer periphery of the cover plate 92; the cover plate 92 is squeezed toward the bottom wall 115 by using the pre-pressing block of the riveting die, and the annular side wall 111 corresponding to the concave steps 927 of the cover plate 92 is punched and bent toward the axis of the shell 11 by using the rivet head of the riveting die to form rivet feet 119. The rivet feet 119 limit the cover plate 92 at the opening of the shell 11 to achieve the sealing of the entire machine.

[0097] According to the above assembly method, the first gear 5 and the second gear 7 can be assembled at any angle in the circumferential direction, such as Figure 18 As shown, the two first process holes 51 and the two second process holes 71 do not need to be axially symmetrical with respect to the rotor assembly 3 .

[0098] Example 2

[0099] Based on the first embodiment, Figure 11 As shown, one axial end of the bearing 91 is provided with a limiting structure 911 that abuts against the end surface of the flange hole 921 to prevent the bearing 91 and the cover plate 92 from axial movement and causing the bearing 91 to fall off.

[0100] Example 3

[0101] On the basis of the above embodiment, annular grooves 121 are respectively provided at both axial ends of the core shaft 12. Figure 19 As shown, the annular rivet head of the riveting die is used to apply an extrusion force F1 to the bottom wall 115 of the shell 11 to form an annular rivet mark 120. During the application of the extrusion force F1, the solid part of the bottom wall 115 around the center hole 114 begins to displace along the direction of F2, causing the center hole 114 to shrink and generate a clamping force on the core shaft 12. Part of the solid part of the bottom wall 115 is displaced into the annular groove 121, so that the core shaft 12 and the motor shell 11 have a greater pulling force in the axial direction.

[0102] Both ends of the core shaft 12 are provided with annular grooves 121, and the processing technology is formed by mold extrusion, which does not increase additional costs; and both ends of the core shaft 12 are provided with annular grooves 121, so there is no need to identify the direction during the riveting process, which greatly improves the work efficiency of the riveting process of the motor housing 11 and the core shaft 12.

[0103] In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "inner," "outer," "axial," "circumferential," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0104] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A method for assembling a permanent magnet reduction motor, characterized in that: The permanent magnet reduction motor includes a housing assembly, a cover assembly, a rotor assembly, a stator assembly, an output shaft assembly, two primary gears and two secondary gears. The rotor assembly includes a magnetic ring and rotor shaft teeth located at one end of the magnetic ring. The rotor shaft teeth, the primary gear, the secondary gear and the output shaft assembly are meshed and driven in sequence. A chamfer C is provided on the tooth end surface of the rotor shaft teeth so that the two primary gears can rotate and mesh with the rotor shaft teeth at the same time. The method comprises the following steps: S1: Prepare the housing assembly, cover assembly, rotor assembly, stator assembly and output shaft assembly respectively; S2: Assemble the primary gear, secondary gear and output shaft assembly on the stator assembly in sequence, so that the two secondary gears are meshed with the output shaft assembly; assemble the rotor assembly into the housing assembly; S3: Installing the stator assembly assembled in step S2 into the housing assembly so that the two primary gears are meshed with the rotor shaft teeth; S4: Fix the cover assembly and the shell assembly.

2. The method for assembling a permanent magnet reduction motor according to claim 1, wherein: The chamfer angle C is between 10° and 15°.

3. The method for assembling a permanent magnet reduction motor according to claim 1, wherein: The shell assembly includes a shell and a core shaft, the shell includes a bottom wall and an annular side wall, an annular groove is provided at one or both axial ends of the core shaft, and one end of the core shaft with the annular groove is riveted and fixed in the center hole of the bottom wall.

4. The method for assembling a permanent magnet reduction motor according to claim 3, wherein: The assembly steps of the shell assembly are: first, the core shaft is inserted into the center hole, and the annular groove is located in the center hole, and then the annular rivet head of the riveting mold is used to rivet annular rivet marks on the lower surface of the bottom wall of the shell to make the center hole shrink and hold the annular groove tightly.

5. The method for assembling a permanent magnet reduction motor according to claim 1, wherein: The cover plate assembly includes a bearing and a cover plate, the output shaft is cooperatively connected with the bearing, a flanging hole is provided at the center of the cover plate, the bearing is installed in the flanging hole, and one axial end of the bearing is provided with a limiting structure that abuts against the end face of the flanging hole.

6. The method for assembling a permanent magnet reduction motor according to claim 5, wherein: The outer edge of the cover plate is provided with a plurality of concave steps. The cover plate is located on the end of the annular side wall away from the bottom wall and abuts against the inner wall of the annular side wall. The annular side wall is punched and bent in the axial direction to form rivet feet corresponding to the concave steps.

7. The method for assembling a permanent magnet reduction motor according to claim 1, wherein: It also includes a gear bracket placed at one end of the stator assembly, the wheel of the first-stage gear is axially limited between the gear bracket and the stator assembly, and the wheel of the second-stage gear is axially limited between the gear bracket and the output shaft assembly.

8. The method for assembling a permanent magnet reduction motor according to claim 7, wherein: The stator assembly includes a coil assembly and a fixed plate assembly located at one axial end of the coil assembly. The end surface of the fixed plate assembly is provided with a first gear shaft for two primary gears to pass through and a second gear shaft for two secondary gears to pass through. The gear bracket has a semicircular boss that cooperates with the outer circumferential surface of the second gear shaft.

9. The method for assembling a permanent magnet reduction motor according to claim 8, wherein: The coil assembly includes an upper frame, a middle plate and a lower frame that are overlapped with each other. The upper frame and the lower frame have multiple groups of positioning columns and positioning holes that cooperate with each other. Each group of positioning columns and positioning holes adopts interference fit, and the interference fit amount is 0.005~0.02mm.

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