Stepping motor for milling flat lead screw shaft

Abstract

The invention provides a flat milling lead screw shaft stepping motor which is used for converting rotary motion into linear motion through electric energy and comprises a lead screw stepping driving unit, a flat milling lead screw shaft and a guide shaft sleeve, a rotor assembly center shaft of the lead screw stepping driving unit is a lead screw nut, and the flat milling lead screw shaft is embedded in the lead screw nut of the rotor assembly. Rotation is prevented by means of a guide shaft sleeve arranged on an end cover of the stepping drive unit. The flat-milling lead screw shaft stepping motor has the advantages of being compact in structure, flexible in stroke configuration and convenient to assemble and maintain.

Description

Technical Field

[0001] The invention belongs to the technical field of motors, and in particular relates to a stepping motor with a milled flat lead screw shaft. Background Art

[0002] There are three main types of stepper motors used in the prior art to achieve linear motion: external drive, through-shaft, and fixed-shaft. The external drive type usually requires the configuration of guide rails, sliders, lead screw nuts, and other components outside the stepper motor to achieve linear motion. Although the stroke configuration is flexible, the overall structure is complex and not suitable for applications in places with limited space. The lead screw nut of the through-shaft stepper motor is built into the body, and the motion stroke can be flexibly adjusted by configuring lead screws of different lengths. Although linear motion can be achieved by only configuring an external anti-rotation device to prevent the lead screw from rotating, it is not suitable for applications with high coaxiality requirements. In order to reduce the rotation deviation introduced by the radial clearance of the nut, it is still necessary to configure guide rails and sliders externally to ensure the motion accuracy. It is also not suitable for applications in places with limited space. The fixed-axis stepper motor relies on the spline sleeve and the spline shaft as a rotation stop device. It has a compact structure, but the internal transmission shaft is connected in series by the lead screw and the spline shaft. The motion stroke is limited by the length of the spline shaft, and the linear motion distance cannot be flexibly configured by only changing the length of the lead screw or the spline shaft. At the same time, due to the rotation deviation introduced by the radial clearance of the internal nut, the stroke distance is not easy to be too long, and it is usually only suitable for applications with fixed short stroke requirements.

[0003] In summary, the prior art still lacks a linear motion stepper motor with a compact structure, no need for external devices, flexible stroke configuration, and suitable for use in places with limited space. Therefore, it is indeed necessary to provide a stepper motor structure to overcome the defects of the related technology. Summary of the invention

[0004] The main purpose of the present invention is to provide a milled flat screw shaft stepper motor to solve the problems of limited travel and inflexible configuration of fixed-shaft stepper motors in the prior art.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is to provide a stepper motor with a milled flat lead screw shaft, which includes a lead screw stepper drive unit, a milled flat lead screw shaft and a guide sleeve. The lead screw stepper drive unit is composed of a stator assembly, a front end cover, a rear end cover, a rotor assembly and a rotor bearing. The two ends of the rotor assembly are supported in the inner cavity of the stator assembly by rotor bearings arranged in the front end cover and the rear end cover respectively. The stator assembly and the rotor assembly are fixed as a whole by locking screws connecting the front end cover and the rear end cover. The central axis of the rotor assembly is a lead screw nut; the outer surface of the milled flat lead screw shaft is provided with a spiral groove that matches the lead screw nut in the rotor assembly and at least one milled flat surface milled along the axial side, and the milled flat lead screw shaft is nested in the lead screw nut of the rotor assembly; the guide sleeve is provided with a sliding surface that matches the axial outer contour of the milled flat lead screw shaft, fixed on the outside of the front end cover or the rear end cover and coaxial with the lead screw nut.

[0006] Furthermore, the milled flat lead screw shaft adopts two, three or four milled flat surfaces, and the milled flat surfaces are symmetrically distributed on the side surfaces of the milled flat lead screw shaft along the axis.

[0007] Furthermore, the fixed guide sleeve is installed by flange, thread or other suitable mechanical connection methods.

[0008] Furthermore, the sliding surface of the guide sleeve is made of self-lubricating material.

[0009] Optionally, the axis of the milled flat screw shaft is provided with an axially through hole.

[0010] Optionally, the lead screw nut of the rotor assembly is connected to a rotating grating or a rotating magnetic grating, and a matching grating reading assembly or a magnetic grating reading assembly is fixed on the outside of the rear end cover.

[0011] Optionally, a reflective linear grating or a linear magnetic grating is axially arranged on the flattened surface of the milled screw shaft, and a matching grating reading component or a magnetic grating reading component is fixed on the outside of the front cover or the rear cover.

[0012] Due to the adoption of the above-mentioned technical scheme, compared with the existing technology, the present invention has the following advantages: the screw nut is built into the machine body, and the guide bushing prevents the milled flat screw shaft from rotating, so linear motion can be achieved without external devices, and the structure is compact and the assembly is simple, which is suitable for application in places with limited space; the screw stepping drive unit and the milled flat screw shaft are separable, and the movement stroke only needs to be determined by configuring milled flat screw shafts of different lengths, and the configuration is flexible; the guide bushing is used to ensure the straightness of the movement of the milled flat screw shaft, and the rotation deviation introduced by the radial gap of the screw nut can be eliminated; the milled flat screw shaft can be disassembled and replaced on site, which is convenient for product assembly and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1It is a cross-sectional diagram of the basic structure of a stepper motor with a milled flat screw shaft.

[0014] Figure 2 This is a view of the stepper motor body with a milled flat screw shaft.

[0015] Figure 3 It is a schematic diagram of the cross section of the milled flat screw shaft.

[0016] Figure 4 This is the exploded structure diagram of a stepper motor with a milled flat screw shaft and a flange-connected guide sleeve.

[0017] Figure 5 It is a view and exploded structure diagram of the stepper motor body with a milled flat screw shaft that uses a threaded guide sleeve.

[0018] Figure 6 It is a schematic diagram of the cross-section of the structure of a stepper motor with a milled flat screw shaft for setting a rotating grating.

[0019] Figure 7 It is a schematic diagram of the cross-section of the structure of a stepper motor with a milled flat screw shaft and a reflective linear grating.

[0020] In the figure: 100, milled flat screw shaft stepper motor; 10, screw stepper drive unit; 11, stator assembly; 12, rotor assembly; 13, screw nut; 14, rotor bearing; 15, front end cover; 16, rear end cover; 17, mounting screw hole; 18, center threaded hole; 20, milled flat screw shaft; 21, spiral groove; 22, milled flat surface; 23, through hole; 30, guide bushing; 31, sliding surface; 32, flange mounting hole; 33, mounting external thread; 34, mounting screw; 35, locking screw sleeve; 40, rotating grating; 41, reflective linear grating; 42, grating reading assembly. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation examples: Figure 1 , Figure 2 As shown, a milled flat screw shaft stepper motor 100 according to the present invention includes a screw stepper drive unit 10 , a milled flat screw shaft 20 and a guide sleeve 30 .

[0022] The screw stepping drive unit 10 is composed of a stator assembly 11, a rotor assembly 12, a rotor bearing 14, a front end cover 15, and a rear end cover 16. The two ends of the rotor assembly 12 are supported in the inner cavity of the stator assembly 11 by the rotor bearings 14 arranged in the front end cover 15 and the rear end cover 16 respectively. The stator assembly 11 and the rotor assembly 12 are fixed as a whole by locking screws connecting the front end cover 15 and the rear end cover 16. The central axis of the rotor assembly 12 is the screw nut 13.

[0023] The outer dimensions of the lead screw stepper drive unit 10 adopt the standard dimensions of general stepper motors such as 20, 28, 35, 39, 42, 57, 60, 86, 110 or other suitable dimensions.

[0024] The outer surface of the milled flat lead screw shaft 20 is provided with a spiral groove 21 matching the lead screw nut 13 in the rotor assembly 12 and at least one milled flat surface 22 milled along the axial side. The milled flat lead screw shaft 20 is nested in the lead screw nut 13 of the rotor assembly 12.

[0025] The guide sleeve 30 is provided with a sliding surface 31 matching the outer contour of the radial cross section of the milled flattened screw shaft 20 , is fixed to the outside of the front end cover 15 or the rear end cover 16 and is coaxial with the screw nut 13 .

[0026] The flattened screw shaft 20 can be milled using a ( Figure 3 a) Milling flat surface 22, or two ( Figure 3 b) Three ( Figure 3 c) or four ( Figure 3 d) The milled flat surface 22 is symmetrically distributed along the axis, and the sliding surface 31 of the matching guide sleeve 30 fits with the axial outer contour surface of the milled flat screw shaft 20 to ensure that the milled flat screw shaft 20 does not form relative rotation in the guide sleeve 30.

[0027] The guide sleeve 30 can be fixedly mounted on the outside of the front cover 15 or the rear cover 16 by flange, thread or other suitable mechanical connection methods. Figure 4 ) mode, a mounting screw hole 17 is provided on the front cover 15 or the rear cover 16, a corresponding flange mounting hole 32 is provided on the guide sleeve 30, and fixed by mounting screws 34; threaded mounting ( Figure 5 ) mode, an inner center threaded hole 18 is provided on the front end cover 15 or the rear end cover 16, and a corresponding mounting external thread 33 is provided on the guide sleeve 30. The guide sleeve 30 is screwed into the center threaded hole 18 through the external thread 33 and is fixed by installing a locking screw sleeve 35.

[0028] The sliding surface 31 of the guide sleeve 30 may be made of self-lubricating materials such as polytetrafluoroethylene, oil-containing nylon, polyphenylene sulfide, polyetheretherketone, copper composite graphite, and oil-containing powder metallurgy.

[0029] like Figure 6 As shown, in order to achieve closed-loop control of the rotation angle of the screw nut 13 of the rotor assembly 12 of the screw stepper drive unit 10, the screw nut 13 of the rotor assembly 12 is fixedly connected to a rotating grating 40, and a matching grating reading assembly 42 is fixed on the outside of the rear end cover 16.

[0030] like Figure 7As shown, in order to achieve closed-loop control of the linear motion accuracy of the milling screw shaft 20 of the milling screw shaft stepper motor 100, a reflective linear grating 41 is axially embedded on the surface of any milled flat surface 22 of the milling screw shaft 20, and the matching grating reading component 42 is fixed on the outside of the rear end cover 16.

[0031] In order to facilitate the passage of liquid or gaseous media, the axis of the milled flat screw shaft 20 may be provided with an axial through hole 23 .

[0032] The rotating grating 40, the reflective linear grating 41 and the matching grating reading assembly 42 may also be replaced by a magnetic scale and a magnetic grating reading assembly.

[0033] The above description is only a specific implementation mode 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 changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A milling flat screw shaft stepper motor, comprising a screw stepper drive unit, a milling flat screw shaft and a guide sleeve, characterized in that: The screw stepping drive unit is composed of a stator assembly, a front end cover, a rear end cover, a rotor assembly, and a rotor bearing. The two ends of the rotor assembly are supported in the inner cavity of the stator assembly by rotor bearings arranged in the front end cover and the rear end cover respectively. The stator assembly and the rotor assembly are fixed as a whole by locking screws connecting the front end cover and the rear end cover. The central axis of the rotor assembly is a screw nut; the outer surface of the milled flat screw shaft is provided with a spiral groove that matches the screw nut in the rotor assembly and at least one milled flat surface milled along the axial side, and the milled flat screw shaft is nested in the screw nut of the rotor assembly; the guide sleeve is provided with a sliding surface that matches the axial outer contour of the milled flat screw shaft, is fixed to the outside of the front end cover or the rear end cover and is coaxial with the screw nut.

2. A milling flat screw shaft stepper motor according to claim 1, characterized in that: The milled flat lead screw shaft has two, three or four milled flat surfaces, and the milled flat surfaces are symmetrically distributed on the side surfaces of the milled flat lead screw shaft along the axis.

3. A milling flat screw shaft stepper motor according to claim 1, characterized in that: The fixed guide sleeve is installed by flange, thread or other suitable mechanical connection methods.

4. A milling flat screw shaft stepper motor according to claim 1, characterized in that: The sliding surface of the guide sleeve is made of self-lubricating material.

5. A milled flat screw shaft stepper motor according to claim 1, characterized in that: The axis center of the milled flat screw shaft is provided with a through hole along the axial direction.

6. A milled flat screw shaft stepper motor according to claim 1, characterized in that: The lead screw nut of the rotor assembly is connected with a rotating grating or a rotating magnetic grating, and a matching grating reading assembly or a magnetic grating reading assembly is fixed on the outside of the rear end cover.

7. A milling flat screw shaft stepper motor according to claim 1, characterized in that: The flattened surface of the flattened lead screw shaft is axially provided with a reflective linear grating or a linear magnetic grating, and a matching grating reading component or a magnetic grating reading component is fixed on the outside of the front end cover or the rear end cover.

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