A hollow shaft stepping motor rotor and a stepping motor with the same

Abstract

The application relates to a hollow shaft stepping motor rotor and a stepping motor with the same, wherein the rotor comprises a hollow shaft, a front rotor core, a rear rotor core, a front magnetic steel and a rear magnetic steel; the hollow shaft is sequentially inserted into the front rotor core and the rear rotor core; the front magnetic steel is arranged in a mounting groove of the front rotor core; and the rear magnetic steel is arranged in a mounting groove of the rear rotor core. Compared with the prior art, the hollow shaft hole diameter can be maximized under the condition of ensuring the output of the motor, and the strict requirements of application occasions on the large hollow shaft of the motor are met.

Description

Technical Field

[0001] This invention relates to a stepper motor rotor, and more particularly to a hollow shaft stepper motor rotor and a stepper motor having the rotor. Background Technology

[0002] like Figure 1-2 As shown, the existing stepper motor rotor assembly consists of an existing hollow rotor shaft 2, an existing front rotor core 3, an existing rear rotor core 4, and an existing magnet 5 located between the two rotor cores. The existing front rotor core 3 and the existing rear rotor core 4 are deflected at a certain angle in the radial direction. The material of the existing magnet 5 is preferably neodymium iron boron (NdFeB).

[0003] like Figure 3 As shown, in the existing design, the existing hollow rotor shaft 2 passes through the existing front rotor core 3, the existing rear rotor core 4, and the existing magnet 5. The outer diameter of the hollow shaft is the same as the inner diameter R_ID of the front and rear rotor cores, while the inner diameter of the magnet is slightly larger than the inner diameter R_ID of the rotor cores. The existing magnet 5 is the source of the motor rotor's magnetic field, and its cross-sectional area directly affects the motor's output. The magnet area depends on the inner and outer diameters R_ID and R_OD of the motor rotor cores, and the rotor's inner diameter depends on the inner diameter S_ID of the hollow shaft.

[0004] In existing hollow shaft motor designs, the hollow shaft bore diameter S_ID and the motor rotor magnetic field are highly correlated, and the hollow shaft bore diameter and motor output cannot be satisfied simultaneously.

[0005] 1) Increasing the diameter of the hollow shaft hole S_ID will reduce the area of ​​the existing magnet 5 and reduce the motor output.

[0006] 2) To ensure motor output, for motors of the same thickness, only the area of ​​the magnet can be increased, which will reduce the diameter of the hollow shaft S_ID, and the requirements of the application for the diameter cannot be met. Summary of the Invention

[0007] The purpose of this invention is to overcome the defects of the prior art by providing a hollow shaft stepper motor rotor and a stepper motor with the rotor.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] According to one aspect of the present invention, a hollow shaft stepper motor rotor is provided, comprising a hollow shaft, a front rotor core, a rear rotor core, a front magnet, and a rear magnet, wherein the hollow shaft is sequentially inserted into the front rotor core and the rear rotor core, the front magnet is disposed in a mounting groove of the front rotor core, and the rear magnet is installed in a mounting groove of the rear rotor core.

[0010] As a preferred technical solution, the rotor also includes a magnetic shielding sheet, which is installed between the front rotor core and the rear rotor core.

[0011] As a preferred technical solution, the magnetic shielding sheet is a component made of non-magnetic material.

[0012] As a preferred technical solution, the front rotor core and the rear rotor core are in direct contact.

[0013] As a preferred technical solution, both the front magnet and the rear magnet are components made of SmCo samarium cobalt permanent magnets.

[0014] As a preferred technical solution, the front rotor core and the rear rotor core are deflected by a set angle in the radial direction, so that the polarities of the front magnet and the rear magnet are opposite in the radial direction of the rotor.

[0015] As a preferred technical solution, both the front rotor core and the rear rotor core are provided with a number of rotor teeth.

[0016] As a preferred technical solution, a plurality of rotor slots are defined between the rotor teeth, and the front magnet and the rear magnet are respectively placed in the rotor slots of the corresponding rotor core.

[0017] As a preferred technical solution, the inner diameter S_ID of the hollow shaft and the outer diameter R_OD of the rotor have the following relationship: S_ID / R_OD≥0.7.

[0018] According to another aspect of the invention, a stepper motor is provided, the motor comprising a stator and the hollow shaft stepper motor rotor described above.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] This invention adjusts the combination of rotor core and magnets to make the hollow shaft aperture of the hollow shaft motor less correlated with the magnetic field of the motor rotor. Under the condition of ensuring the output of the motor, the hollow shaft aperture can be maximized, which meets the strict requirements of the application for a large hollow shaft of the motor. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of an existing stepper motor rotor;

[0022] Figure 2 This is a schematic diagram of the exploded structure of an existing stepper motor rotor;

[0023] Figure 3 This is a cross-sectional view of an existing stepper motor rotor.

[0024] Figure 4 This is a schematic diagram of the hollow shaft stepper motor rotor in this invention;

[0025] Figure 5 This is an exploded structural diagram of the rotor of the hollow shaft stepper motor in this invention;

[0026] Figure 6 This is a schematic diagram of the main structure of the hollow shaft stepper motor rotor in this invention;

[0027] Figure 7 This is a cross-sectional view of the rotor of the hollow shaft stepper motor in this invention.

[0028] Figure 8 This is a schematic diagram of the rotor core structure of the hollow shaft stepper motor rotor in this invention;

[0029] Wherein 1 is an existing rotor assembly, 2 is an existing hollow rotor shaft, 3 is an existing front rotor core, 4 is an existing rear rotor core, 5 is an existing magnet, 6 is the rotor of the motor of the present invention, 7 is a hollow shaft, 8 is a front rotor core, 9 is a rear rotor core, 10 is a front magnet, 11 is a rear magnet, 12 is a magnetic shielding sheet, 13 is a rotor tooth, and 14 is a rotor slot. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0031] like Figure 4-5 As shown, a hollow shaft stepper motor rotor includes a hollow shaft 7, a front rotor core 8, a rear rotor core 9, a front magnet 10, and a rear magnet 11. The hollow shaft 7 is sequentially inserted into the front rotor core 8 and the rear rotor core 9. The front magnet 10 is disposed in the mounting groove of the front rotor core 8, and the rear magnet 11 is installed in the mounting groove of the rear rotor core 9. This invention eliminates the magnet located between the front and rear rotor cores; the front magnet 10 and the rear magnet 11 serve as the source of the motor rotor magnets, replacing the original magnet located between the front and rear rotor cores.

[0032] One embodiment is as follows: the rotor further includes a magnetic shielding sheet 12, which is installed between the front rotor core 8 and the rear rotor core 9. The magnetic shielding sheet 12 is a component made of non-magnetic material and only serves a physical separation function.

[0033] Another implementation is that the front rotor core 8 and the rear rotor core 9 are in direct contact.

[0034] Both the front magnet 10 and the rear magnet 11 are components made of SmCo samarium cobalt permanent magnets.

[0035] like Figure 6-7 As shown, the front rotor core 8 and the rear rotor core 9 are deflected by a set angle in the radial direction, so that the front magnet 10 and the rear magnet 11 have opposite polarities in the rotor radial direction. For example, if the front magnet 10 on the front rotor core 8 has N poles facing outward in the circumferential direction, then the rear magnet 11 on the rear rotor core 9 has S poles facing outward in the circumferential direction.

[0036] like Figure 8 As shown, both the front rotor core 8 and the rear rotor core 9 have a plurality of rotor teeth 13 distributed on them. The rotor teeth 13 define a plurality of rotor slots 14, and the front magnet 10 and the rear magnet 11 are respectively placed in the rotor slots 14 of the corresponding rotor cores.

[0037] In this invention, the rotor magnetic field originates from the magnets within the rotor slots on the outer surface of the rotor core and is not strongly correlated with the rotor inner diameter R_ID. In other words, the inner diameter S_ID of the hollow shaft is unrelated to the strength of the motor's rotor magnetic field. Theoretically, the aperture of the hollow shaft is only limited by the rotor outer diameter and the wall thickness of the hollow shaft (R_ID - S_ID).

[0038] In this invention, while ensuring the output of the motor, the inner diameter S_ID of the hollow shaft 7 and the outer diameter R_OD of the rotor have the following relationship: S_ID / R_OD≥0.7.

[0039] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A hollow shaft stepper motor rotor, characterized in that, It includes a hollow shaft (7), a front rotor core (8), a rear rotor core (9), a front magnet (10), and a rear magnet (11). The hollow shaft (7) is inserted into the front rotor core (8) and the rear rotor core (9) in sequence. The front magnet (10) is located in the mounting groove of the front rotor core (8), and the rear magnet (11) is installed in the mounting groove of the rear rotor core (9). The inner diameter S_ID of the hollow shaft is limited only by the outer diameter R_OD of the rotor and the wall thickness of the hollow shaft. The inner diameter S_ID of the hollow shaft (7) and the outer diameter R_OD of the rotor have the following relationship: S_ID / R_OD≥0.

7.

2. The hollow shaft stepper motor rotor according to claim 1, characterized in that, The rotor also includes a magnetic shielding sheet (12) which is installed between the front rotor core (8) and the rear rotor core (9).

3. A hollow shaft stepper motor rotor according to claim 2, characterized in that, The magnetic shielding sheet (12) is a component made of non-magnetic material.

4. A hollow shaft stepper motor rotor according to claim 1, characterized in that, The front rotor core (8) and the rear rotor core (9) are in direct contact.

5. A hollow shaft stepper motor rotor according to claim 1, characterized in that, Both the front magnet (10) and the rear magnet (11) are components made of SmCo permanent magnets.

6. A hollow shaft stepper motor rotor according to claim 1, characterized in that, The front rotor core (8) and the rear rotor core (9) are deflected by a set angle in the radial direction, so that the front magnet (10) and the rear magnet (11) have opposite polarities in the rotor radial direction.

7. A hollow shaft stepper motor rotor according to claim 1, characterized in that, Both the front rotor core (8) and the rear rotor core (9) have a number of rotor teeth (13) distributed on them.

8. A hollow shaft stepper motor rotor according to claim 7, characterized in that, The rotor teeth (13) define a plurality of rotor slots (14), and the front magnet (10) and the rear magnet (11) are respectively placed in the rotor slots (14) of the corresponding rotor cores.

9. A stepper motor, characterized in that, The motor includes a stator and a hollow shaft stepper motor rotor as described in any one of claims 1-8.

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