Stepping motor

Abstract

The invention relates to a stepping motor which comprises a motor stator iron core, a motor front end cover, a motor rear end cover, a front rotor iron core, a rear rotor iron core, rotor magnetic steel, a motor front bearing, a motor rear bearing and a rotating shaft, and the rotating shaft sequentially penetrates through the motor front end cover, the motor front bearing, the front rotor iron core, the rear rotor iron core, the motor rear bearing and the motor rear end cover. The side, facing the motor front bearing, of the front rotor iron core is provided with a first groove for the motor front bearing to be partially inserted, and the side, facing the motor rear bearing, of the rear rotor iron core is provided with a second groove for the motor rear bearing to be partially inserted. Compared with the prior art, the invention has the advantages of using a bearing with a larger size and reducing the axial length of the motor while ensuring that the output of the motor is not changed, and the like.

Description

Technical Field

[0001] The invention relates to a motor, in particular to a stepping motor. Background Art

[0002] like Figure 1 As shown, the existing hybrid stepper motor includes a motor stator core 1, a motor front cover 2, a motor rear cover 3, a front rotor core 4, a rear rotor core 5, a rotor magnetic steel 6, a motor front bearing 7, a motor rear bearing 8 and a rotating shaft 9. In the existing stepper motor solution, there is a certain proportional relationship between the rotor outer diameter R_OD and the stator outer diameter S_OD: 0.45*S_OD <R_OD<0.65*S_OD;

[0003] In this design, in order to reduce the inertia of the motor rotor, the rotor core on the side away from the magnetic steel will be hollowed out. Figure 1 As shown, the hollowed diameter is R_D: R_D<0.6*R_OD; the life of the motor generally depends on the life of the motor bearing. The larger the bearing size, the stronger the load-bearing capacity. In motors with the same output, the larger the bearing used, the longer the life of the motor. If a bearing with a larger load-bearing capacity is used, the thickness of the bearing will inevitably increase, and the axial length L of the motor will also increase. In many occasions with strict dimensional requirements, the life of the motor and the length of the motor will restrict each other.

[0004] Therefore, how to use larger bearings and reduce the axial length of the motor while ensuring that the motor output remains unchanged has become a technical problem that needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a stepping motor to overcome the defects of the prior art, by using a larger bearing and reducing the axial length of the motor while ensuring that the motor output remains unchanged.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] According to one aspect of the present invention, a stepper motor is provided, comprising a motor stator core, a motor front end cover, a motor rear end cover, a front rotor core, a rear rotor core, a rotor magnet, a motor front bearing, a motor rear bearing and a rotating shaft, wherein the rotating shaft is sequentially inserted into the motor front end cover, the motor front bearing, the front rotor core, the rear rotor core, the motor rear bearing and the motor rear end cover, and is characterized in that a first groove for inserting a part of the front bearing of the motor is provided on a side of the front rotor core facing the front bearing of the motor, and a second groove for inserting a part of the rear bearing of the motor is provided on a side of the rear rotor core facing the rear bearing of the motor.

[0008] As a preferred technical solution, the rotor hollow inner diameter R_D1 of the first groove and the second groove is larger than the bearing outer diameter B_OD1.

[0009] As a preferred technical solution, the specific relationship between the rotor hollowing inner diameter R_D1 and the rotor outer diameter R_OD1 of the first groove and the second groove is as follows:

[0010] 0.65*R_OD1 <R_D1。

[0012] As a preferred technical solution, the specific relationship between the outer diameter S_OD1 of the motor stator core and the outer diameter R_OD1 of the rotor is as follows:

[0013] 0.65*S_OD1 <R_OD1。

[0015] As a preferred technical solution, the depth of the first groove and the second groove is greater than the insertion depth of the bearing.

[0016] As a preferred technical solution, the length of the front bearing of the motor inserted into the first groove is one tenth to one third of the total length of the bearing.

[0017] As a preferred technical solution, the length of the motor front bearing inserted into the first groove is one fifth of the total length of the bearing.

[0018] As a preferred technical solution, the length of the rear bearing of the motor inserted into the second groove is one tenth to one third of the total length of the bearing.

[0019] As a preferred technical solution, the length of the rear bearing of the motor inserted into the second groove is one fifth of the total length of the bearing.

[0020] As a preferred technical solution, the overall length L1 of the motor is shortened.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] The motor of the present invention ensures that the motor output remains unchanged while the motor uses bearings of larger sizes, thereby greatly improving the life and reliability of the motor. At the same time, the axial length of the newly designed motor is reduced, and can be applied to applications that have requirements on the axial length of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of an existing motor;

[0024] Figure 2 It is a schematic diagram of the structure of the motor of the present invention.

[0025] 1 is the motor stator core, 2 is the motor front cover, 3 is the motor rear cover, 4 is the front rotor core, 5 is the rear rotor core, 6 is the rotor magnet, 7 is the motor front bearing, 8 is the motor rear bearing, 9 is the shaft,

[0026] B_ID is the shaft outer diameter / bearing inner diameter of the existing motor, B_OD is the bearing outer diameter of the existing motor,

[0027] S_OD is the stator core outer diameter of the existing motor, R_OD is the rotor outer diameter of the existing motor,

[0028] R_D is the hollow inner diameter of the rotor of the existing motor, and L is the entire length of the existing motor.

[0029] B_ID1 is the outer diameter of the shaft / inner diameter of the bearing of the motor of the present invention, and B_OD1 is the outer diameter of the bearing of the motor of the present invention;

[0030] R_OD1 is the outer diameter of the rotor of the motor of the present invention, and R_D1 is the hollow inner diameter of the rotor of the motor of the present invention;

[0031] L1 is the overall length of the motor of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0033] like Figure 2 As shown, a stepper motor of the present invention comprises a motor stator core 1, a motor front end cover 2, a motor rear end cover 3, a front rotor core 4, a rear rotor core 5, a rotor magnetic steel 6, a motor front bearing 7, a motor rear bearing 8 and a rotating shaft 9, wherein the rotating shaft 9 sequentially penetrates the motor front end cover 2, the motor front bearing 7, the front rotor core 4, the rear rotor core 5, the motor rear bearing 8 and the motor rear end cover 3, and the front rotor core 4 is provided with a first groove for partially inserting the motor front bearing 7 on the side facing the motor front bearing 7, and the rear rotor core 5 is provided with a second groove for partially inserting the motor rear bearing 8 on the side facing the motor rear bearing 8.

[0034] The depth of the first groove and the second groove is greater than the insertion depth of the bearing; the length of the motor front bearing 7 inserted into the first groove is one tenth to one third of the total length of the bearing; further preferably, the length of the motor front bearing 7 inserted into the first groove is one fifth of the total length of the bearing.

[0035] The length of the motor rear bearing 8 inserted into the second groove is one tenth to one third of the total length of the bearing. Further preferably, the length of the motor rear bearing 8 inserted into the second groove is one fifth of the total length of the bearing.

[0036] In the solution of the present invention, in order to use a larger-sized bearing, improve the bearing capacity of the bearing, and thus improve the life of the motor, the method includes:

[0037] 1)0.65*S_OD1 <R_OD1

[0038] 2) 0.65*R_OD1 <R_D1

[0039] 3) B_OD1 <R_D1

[0040] Under this design, the outer diameter of the motor bearing is smaller than the outer diameter of the hollowed-out rotor core, so a portion of the motor bearing can be placed in the rotor, saving the axial dimension of the motor and shortening the length L1 of the motor.

[0041] As shown in Table 1, a stepper motor with a 42 mm shape is used as an example to illustrate the comparison between the present invention and the original design.

[0042] As can be seen from the table below, in the existing design, 625 bearings are used, and the inner and outer diameter thicknesses of the bearings are 5mm, 16mm and 5mm respectively. The outer diameter of the motor rotor is small, and the outer diameter of the rotor hollowing is also small; even if the outer diameter of the rotor hollowing is increased (limited by some process restrictions), it is impossible to place a bearing with a larger outer diameter.

[0043] In the present invention, the rotor is designed to have an outer diameter of 30 mm and a hollow inner diameter of 22.6 mm, and can be placed in a 608 bearing, and the inner and outer diameter thicknesses of the bearing are 8 mm, 22 mm and 7 mm respectively.

[0044] With the addition of the above design, the thickness of the motor is also reduced to a certain extent while ensuring the performance of the motor.

[0045] Table 1

[0046] Existing Design The present invention Motor stator outer diameter (mm) 42 42 Motor rotor outer diameter (mm) 25.9 30 Rotor hollow inner diameter (mm) 15 22.6 Bearing outer diameter (mm) 16 22 Bearing inner diameter (mm) 5 8 Bearing thickness (mm) 5 7 Motor length (mm) 32.1 31.3

[0047] The motor of the present invention ensures that the motor output remains unchanged while the motor uses bearings of larger sizes, thereby greatly improving the life and reliability of the motor. At the same time, the axial length of the newly designed motor is reduced, and can be applied to applications that have requirements on the axial length of the motor.

[0048] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A stepper motor, comprising a motor stator core (1), a motor front end cover (2), a motor rear end cover (3), a front rotor core (4), a rear rotor core (5), a rotor magnetic steel (6), a motor front bearing (7), a motor rear bearing (8) and a rotating shaft (9), wherein the rotating shaft (9) sequentially penetrates the motor front end cover (2), the motor front bearing (7), the front rotor core (4), the rear rotor core (5), the motor rear bearing (8) and the motor rear end cover (3), characterized in that: The front rotor core (4) is provided with a first groove for partially inserting the front bearing (7) of the motor on the side facing the front bearing (7) of the motor, and the rear rotor core (5) is provided with a second groove for partially inserting the rear bearing (8) of the motor on the side facing the rear bearing (8) of the motor.

2. A stepper motor according to claim 1, characterized in that: The rotor hollow inner diameter R_D1 of the first groove and the second groove is greater than the bearing outer diameter B_OD1.

3. A stepping motor according to claim 1, characterized in that: The specific relationship between the rotor hollow inner diameter R_D1 and the rotor outer diameter R_OD1 of the first groove and the second groove is as follows: 0.65*R_OD1 <R_D1。 4. A stepping motor according to claim 1, characterized in that: The specific relationship between the outer diameter S_OD1 of the motor stator core and the outer diameter R_OD1 of the rotor is as follows: 0.65*S_OD1 <R_OD1。 5. A stepping motor according to claim 1, characterized in that: The depths of the first groove and the second groove are greater than the insertion depth of the bearing.

6. A stepping motor according to claim 1, characterized in that: The length of the motor front bearing (7) inserted into the first groove is one tenth to one third of the total length of the bearing.

7. A stepping motor according to claim 6, characterized in that: The length of the motor front bearing (7) inserted into the first groove is one fifth of the total length of the bearing.

8. A stepping motor according to claim 1, characterized in that: The length of the motor rear bearing (8) inserted into the second groove is one tenth to one third of the total length of the bearing.

9. A stepping motor according to claim 8, characterized in that: The length of the motor rear bearing (8) inserted into the second groove is one fifth of the total length of the bearing.

10. A stepping motor according to claim 1, characterized in that: The entire length L1 of the motor is shortened.

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