A novel linear actuator structure based on an external rotor rotary motor and a screw pair

Abstract

This invention relates to a push rod based on an external rotor rotary motor and a lead screw pair, belonging to the field of push rod technology. It solves the problems of long axial dimensions of the rotating body in existing external rotor motors and small effective stroke of the lead screw in push rods. The invention includes a reciprocating component, a rotating component, a rotational drive component, a fixed drive component, and a limiting cylinder. The rotating component is threadedly connected to the reciprocating component. One end of the reciprocating component is connected to the inner wall of the limiting cylinder, and the other end is a free end used to push and pull the movable component, causing linear or deflective motion. The rotating component of the push rod of this invention does not require connection to a second rotational support component. The axial dimension of the rotating body in the external rotor motor of this invention is short, and a fixing groove is provided on the limiting cylinder to prevent the reciprocating component from rotating. Therefore, the limiting component is eliminated, further reducing the mass of the push rod. The effective stroke of the reciprocating component can be increased without changing the overall length.

Description

Technical Field

[0001] This invention belongs to the field of linear drive technology, and in particular relates to a push rod based on an external rotor rotary motor and a lead screw pair. Background Technology

[0002] With the continuous development of electric motors and precision machinery, linear actuators have been widely used in various fields. Linear actuators based on rotary motors primarily convert the rotational motion of the motor into linear motion by transmitting the rotating component of the screw pair to the reciprocating component. Compared to solutions using linear motors as the drive source, using rotary motors as the drive source can significantly reduce the axial dimension of the linear actuator, making miniaturization possible.

[0003] To meet the structural stability requirements, the rotating body in an external rotor motor is usually supported by bearings at both ends. The inner rings of the two bearings are interference-fitted with the rotating body, and the outer rings of the two bearings are interference-fitted with the non-rotating body. This requires the axial dimension of the rotating body inside the motor to be long enough to accommodate the bearing installation, which in turn results in a small effective stroke of the lead screw in the push rod.

[0004] Therefore, there is an urgent need for a push rod based on an external rotor rotary motor and a lead screw pair to solve the problems of long axial dimension of the rotating body in the external rotor motor and small effective stroke of the lead screw in the push rod. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a push rod based on an external rotor rotary motor and a lead screw pair, which solves the problems of long axial dimension of the rotating body in the external rotor motor and small effective stroke of the lead screw in the push rod in the prior art.

[0006] The objective of this invention is mainly achieved through the following technical solutions:

[0007] A push rod based on an external rotor rotary motor and a lead screw pair includes a reciprocating component, a rotating component, a rotational drive component, a fixed drive component, and a limiting cylinder;

[0008] The rotating part and the reciprocating part are threadedly connected. One end of the reciprocating part is connected to the inner wall of the limiting cylinder, and the other end of the reciprocating part is a free end. The free end is used to push and pull the moving part, so that the moving part can move linearly or deflect.

[0009] The rotating drive component and the fixed drive component constitute the external rotor motor. The external rotor motor is used to drive the rotating component to rotate, and in turn, drive the reciprocating component to extend and retract on the limiting cylinder.

[0010] Furthermore, it also includes a transmission sleeve, through which the rotation drive component is connected to the outer wall of the rotating component.

[0011] Furthermore, it also includes a cover and a first rotating support member, one end of which is connected to the cover through the first rotating support member, and the rotating member can rotate inside the cover.

[0012] Furthermore, the limiting cylinder includes a first connecting portion.

[0013] Furthermore, it also includes a second rotating support member, the inner ring of which is connected to the first connecting part, and the outer ring of which is connected to one end of the transmission sleeve.

[0014] Furthermore, the limiting cylinder also includes a second connecting part, and the fixing drive member is disposed on the outer wall of the second connecting part.

[0015] Furthermore, it also includes an end cap, which is connected to the first connecting portion.

[0016] Furthermore, the reciprocating component includes a first reciprocating part, which is used to connect with the rotating component.

[0017] Furthermore, the reciprocating component also includes a second reciprocating part, which is provided with an anti-rotation block.

[0018] Furthermore, the limiting cylinder also includes a fixing groove, which is disposed on the inner wall of the first connecting part. The anti-rotation block can be connected to the fixing groove and can slide on the fixing groove, thereby preventing the reciprocating part from rotating.

[0019] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0020] (1) Compared with the prior art, the rotating part of the push rod of the present invention does not need to be connected to the first rotating support and the second rotating support. The axial dimension of the rotating body in the external rotor motor of the present invention is short, and the fixing groove is provided on the limiting cylinder to prevent the reciprocating part from rotating. Therefore, the limiting part is removed, the mass of the push rod is further reduced, and the effective stroke of the reciprocating part can be increased without changing the total length.

[0021] (2) The outer wall of the transmission sleeve of the present invention can be connected to the inner ring of the first rotating support member, the push rod of the present invention can eliminate the gap of the prior art, and correspondingly, the rotating member can remove the same length as the gap width, the length of the rotating member is further shortened, and the effective stroke of the reciprocating member of the present invention is further lengthened.

[0022] (3) The push rod of the present invention is provided with a limiting cylinder groove on the limiting cylinder, and the second reciprocating part is replaced with a modified second reciprocating part and a positioning sleeve. The positioning sleeve can be inserted into the limiting cylinder groove. The thickness of the modified second reciprocating part and the positioning sleeve in the axial direction is equal to the thickness of the second reciprocating part. Without changing the minimum anti-deflection thickness, the effective stroke of the reciprocating part is further increased.

[0023] (4) The first rotating support component of the present invention is a superconducting magnetic levitation bearing. The high-temperature superconducting magnetic levitation bearing consists of a bearing rotor and a bearing stator. The bearing rotor provides a gradient magnetic field, and the bearing stator is affected by the magnetic field to generate magnetic levitation force, which is used to maintain the operation of the superconducting magnetic levitation bearing. The superconducting magnetic levitation bearing does not require lubrication maintenance, has good stability and long service life, and is suitable for use in aerospace and other fields that require maintenance-free operation.

[0024] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the specification or be learned by practicing the invention. The objectives and other advantages of this invention can be realized and obtained from the content specifically pointed out in the text and drawings. Attached Figure Description

[0025] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0026] Figure 1 This is a schematic diagram of the axial cross-section structure of a push rod in the prior art;

[0027] Figure 2 This is a schematic diagram of the axial cross-section of the push rod in Example 1;

[0028] Figure 3 for Figure 1 Enlarged structural diagram of region A in the middle;

[0029] Figure 4 for Figure 2 A magnified structural diagram of region B in the middle;

[0030] Figure 5 These are schematic diagrams of the axial cross-sectional structure of the push rods in Examples 2 and 3;

[0031] Figure 6 for Figure 5 A magnified structural diagram of region C in the middle;

[0032] Figure 7 This is a schematic diagram of the axial cross-section of the push rod in Example 4;

[0033] Figure 8 for Figure 7 A magnified structural diagram of region D in the middle.

[0034] Figure label:

[0035] 1-Reciprocating component; 2-Rotating component; 3-Cover; 4-First rotating support component; 5-Transmission sleeve; 6-Rotating drive component; 7-Fixed drive component; 8-Second rotating support component; 9-End cap; 10-Limiting component; 11-Limiting cylinder; 12-Gap; 13-Misalignment ring groove; 14-Cryogenic Dewar; 15-Outer support component; 16-Refrigeration chamber; 17-Inner support component; 18-Superconducting block; 19-Permanent magnet ring; 20-Magnetic ring; 21-Non-magnetic protective sleeve; 101-First reciprocating part; 102-Second reciprocating part; 103-Resizing second reciprocating part; 104-Positioning sleeve; 111-First connecting part; 112-Second connecting part; 113-Fixed groove; 114-Limiting cylinder groove. Detailed Implementation

[0036] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0037] Existing external rotor push rods, such as Figure 1 As shown, the assembly includes a reciprocating component 1, a rotating component 2, a housing 3, a first rotating support component 4, a transmission sleeve 5, a rotating drive component 6, a fixed drive component 7, a second rotating support component 8, an end cap 9, a limiting component 10, and a limiting cylinder 11. The rotating component 2 is threadedly connected to the reciprocating component 1. One end of the reciprocating component 1 is connected to the inner wall of the limiting cylinder 11, and the other end of the reciprocating component 1 is a push-pull end, used to push and pull the movable component connected to the push rod, causing the movable component to move linearly or deflect. One end of the rotating component 2 is connected to the housing 3 via the first rotating support component 4, and the other end of the rotating component 2 is connected to the end cap 9 via the second rotating support component 8. The rotating component 2 can rotate within the housing 3 and the end cap 9. The housing 3 and the end cap 9 are connected by the limiting component 10. The end cap 9 is disposed on the outer wall of the limiting cylinder 11. The fixed drive component 7 is disposed on the limiting component 10. The rotating drive component 6 is connected to the outer wall of the rotating component 2 via the transmission sleeve 5. The rotating drive 6 and the fixed drive 7 constitute an external rotor motor, which is used to drive the rotating part 2 to rotate, and in turn drive the reciprocating part 1 to extend and retract on the limiting cylinder 11.

[0038] In the existing lead screw pair, when working, the total length of the rotating part 2 and the length of the limiting part 10 are the ineffective stroke of the reciprocating part 1. With the length of the reciprocating part 1 remaining unchanged, the shorter the rotating part 2, the longer the effective stroke of the reciprocating part 1.

[0039] Example 1

[0040] A specific embodiment of the present invention, such as Figure 2As shown, a push rod (hereinafter referred to as push rod) based on an external rotor rotary motor and a lead screw pair is disclosed, including a reciprocating component 1, a rotating component 2, a cover 3, a first rotating support component 4, a transmission sleeve 5, a rotating drive component 6, a fixed drive component 7, a second rotating support component 8, an end cover 9, and a limiting cylinder 11, excluding the limiting component 10.

[0041] Rotating component 2 is threadedly connected to reciprocating component 1. One end of reciprocating component 1 is connected to the inner wall of limiting cylinder 11, and the other end of reciprocating component 1 is a free end. The free end is used to push and pull the movable component, so that the movable component can move linearly or deflect.

[0042] Preferably, one end of the rotating part 2 is connected to the cover 3 through the first rotating support 4, and the other end of the rotating part 2 is no longer connected to the second rotating support 8. The rotating part 2 can rotate inside the cover 3. The rotating drive 6 is connected to the outer wall of the rotating part 2 through the transmission sleeve 5. The rotating drive 6 and the fixed drive 7 constitute an external rotor motor and are used to drive the rotating part 2 to rotate, thereby driving the reciprocating part 1 to extend and retract on the limiting cylinder 11.

[0043] Preferably, the limiting cylinder 11 includes a first connecting portion 111 and a second connecting portion 112. The inner ring and end cap 9 of the second rotating support member 8 are both connected to the first connecting portion 111, and the outer ring of the second rotating support member 8 is connected to one end of the transmission sleeve 5. The fixed driving member 7 is disposed on the outer wall of the second connecting portion 112, so the limiting member 10 can be removed.

[0044] Preferably, the reciprocating component 1 includes a first reciprocating part 101 and a second reciprocating part 102. The first reciprocating part 101 is used to connect with the rotating component 2, and the second reciprocating part 102 is provided with an anti-rotation block (not shown in the figure). The limiting cylinder 11 also includes a fixing groove 113, which is disposed on the inner wall of the first connecting part 111. The anti-rotation block can connect with the fixing groove 113 and slide on the fixing groove 113, thereby preventing the reciprocating component 1 from rotating.

[0045] Preferably, the rotating component 2 does not need to be connected to the second rotating support component 8, the length of the rotating component 2 can be shortened, and the total mass of the push rod in this embodiment can be reduced.

[0046] Compared to the prior art where the rotating part 2 needs to be connected to the first rotating support 4 and the second rotating support 8, the rotating part 2 provided in this embodiment does not need to be connected to the second rotating support 8. The axial dimension of the rotating body in the external rotor motor of the present invention is short, the limiting cylinder 11 is provided with a fixing groove 113 to prevent the reciprocating part 1 from rotating, and the limiting part 10 is removed, further reducing the mass of the push rod. Moreover, the effective stroke of the reciprocating part 1 can be increased without changing the total length.

[0047] Example 2

[0048] Another specific embodiment of the push rod of the present invention is as follows: Figure 2 As shown, the structure of the transmission sleeve 5 in Embodiment 1 has been improved by further shortening the rotating part 2 to increase the effective stroke of the push rod.

[0049] like Figure 3 As shown, in the prior art, in order to prevent interference between the transmission sleeve 5 and the outer ring of the first rotating support member 4, the push rod of the prior art has a gap 12 between the transmission sleeve 5 and the first rotating support member 4.

[0050] Preferred, such as Figure 2 and Figure 4 As shown, the transmission sleeve 5 is provided with a misaligned annular groove 13, which is disposed on the outer wall of the transmission sleeve 5 facing the first rotating support member 4. The misaligned annular groove 13 is used to prevent the transmission sleeve 5 from contacting the outer ring of the first rotating support member 4 and the cover 3. Therefore, the outer wall of the transmission sleeve 5 in this embodiment can be connected to the inner ring of the first rotating support member 4, the push rod in this embodiment can eliminate the gap 12, and correspondingly, the rotating member 2 can remove a length equal to the width of the gap 12, the length of the rotating member 2 is further shortened, and the effective stroke of the reciprocating member 1 in this embodiment is further lengthened.

[0051] Example 3

[0052] Another specific embodiment of the push rod of the present invention is as follows: Figure 5 As shown, the structure of the limiting cylinder 11 in Embodiment 1 or Embodiment 2 has been improved by adding a limiting cylinder groove 114. By replacing the second reciprocating part 102 in Embodiment 1 or Embodiment 2 with the modified second reciprocating part 103 and the positioning sleeve 104, the length of the reciprocating part 1 retracting into the limiting cylinder 11 is increased, thereby further increasing the effective stroke of the push rod.

[0053] like Figure 2 As shown, in the prior art, to prevent the reciprocating part 1 from radially deflecting relative to the limiting cylinder 11, the second reciprocating part 102 needs to have a certain thickness in the axial direction, with a thickness of at least 1 / 8 of the screw thread section. The thickness of the second reciprocating part 102 is 'a', which is the minimum anti-deflection thickness. After the reciprocating part 1 retracts into the limiting cylinder 11, the thickness of the second reciprocating part 102 limits the distance the reciprocating part 1 can retract into the bottom end of the limiting cylinder 11. The smaller 'a' is, the greater the distance the reciprocating part 1 can retract into the limiting cylinder 11, and correspondingly, the greater the effective stroke of the reciprocating part 1.

[0054] Preferred, such as Figure 5 and Figure 6As shown, a limiting cylinder groove 114 is provided on the limiting cylinder 11, and the limiting cylinder groove 114 is provided on the inner wall of the second connecting part 112. The second reciprocating part 102 of the reciprocating part 1 is cancelled and replaced with a distance-adjusting second reciprocating part 103 and a positioning sleeve 104. The distance-adjusting second reciprocating part 103 is connected to the first reciprocating part 101, and the outer diameter of the distance-adjusting second reciprocating part 103 is the same as the outer diameter of the second reciprocating part 102. One end of the positioning sleeve 104 is connected to the distance-adjusting second reciprocating part 103, and the other end of the positioning sleeve 104 can be inserted into the limiting cylinder groove 114. The thickness of the distance-adjusting second reciprocating part 103 and the positioning sleeve 104 in the axial direction is equal to a, and the thickness of the distance-adjusting second reciprocating part 103 in the axial direction is less than a. Without changing the minimum anti-deflection thickness, the thickness of the second reciprocating part 102 is reduced, and the effective stroke of the reciprocating part 1 is increased.

[0055] Compared to Embodiments 1 and 2, the push rod in this embodiment has a limiting cylinder groove 114 on the limiting cylinder 11. The second reciprocating part 102 is replaced with a distance-modified second reciprocating part 103 and a positioning sleeve 104. The positioning sleeve 104 can be inserted into the limiting cylinder groove 114. The thickness of the distance-modified second reciprocating part 103 and the positioning sleeve 104 in the axial direction is equal to the thickness of the second reciprocating part 102. Without changing the minimum anti-deflection thickness, the effective stroke of the reciprocating part 1 is further increased.

[0056] Example 4

[0057] Another specific embodiment of the push rod of the present invention is as follows: Figure 7 As shown, the first rotating support 4 is selected as a superconducting magnetic levitation bearing, and the second rotating support 8 is omitted. The high-temperature superconducting magnetic levitation bearing consists of a bearing rotor and a bearing stator. The bearing rotor provides a gradient magnetic field, and the bearing stator generates magnetic levitation force under the influence of the magnetic field, which is used to maintain the operation of the superconducting magnetic levitation bearing. Therefore, the superconducting magnetic levitation bearing requires no lubrication or maintenance, has good stability and long service life, and is suitable for use in aerospace and other fields that require maintenance-free operation.

[0058] Preferably, such as Figure 8 As shown, the superconducting magnetic levitation bearing includes a bearing rotor and a bearing stator. The bearing rotor is a permanent magnet rotor, and the bearing stator is a superconducting stator.

[0059] Preferably, the bearing stator includes a cryogenic Dewar 14, an outer support 15, a cooling chamber 16, an inner support 17, and a superconducting block 18. The outer wall of the cryogenic Dewar 14 is connected to the housing 3. The superconducting block 18 is fixedly mounted on the cooling chamber 16. The cooling chamber 16 is fixedly connected to the cryogenic Dewar 14 through the outer support 15 and the inner support 17. Liquid nitrogen can be introduced into the cooling chamber 16, with a liquid nitrogen temperature range of 77K. The cooling chamber 16 is made of copper material with good thermal conductivity. The cryogenic Dewar 14 can maintain a vacuum environment. Vacuum has a good heat insulation effect and can maintain the low temperature environment of the cooling chamber 16 for a long time. Liquid nitrogen cools the superconducting block 18 to the superconducting temperature range through contact heat transfer.

[0060] Preferably, the bearing rotor includes a permanent magnet ring 19 and a magnet ring 20, with multiple permanent magnet rings 19 and magnet rings 20 arranged alternately. The outer wall of the rotating component 2 is connected to the central hole wall of the permanent magnet ring 19 and the magnet ring 20. The same poles of the two permanent magnet rings 19 are arranged opposite each other. The magnetizing effect of the magnet ring 20 can increase the peak magnetic field of the permanent magnet ring 19.

[0061] Compared with embodiments 1, 2 or 3, the first rotating support 4 of the push rod in this embodiment is a superconducting magnetic levitation bearing. The high-temperature superconducting magnetic levitation bearing consists of a bearing rotor and a bearing stator. The bearing rotor provides a gradient magnetic field, and the bearing stator is affected by the magnetic field to generate magnetic levitation force to maintain the operation of the superconducting magnetic levitation bearing. The superconducting magnetic levitation bearing does not require lubrication and maintenance, has good stability and long service life, and is suitable for use in aerospace and other fields that require maintenance-free operation.

[0062] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A push rod based on an external rotor rotary motor and a lead screw pair, characterized in that, It includes a reciprocating component (1), a rotating component (2), a rotation driving component (6), a fixed driving component (7), and a limiting cylinder (11); The rotating part (2) is threadedly connected to the reciprocating part (1). One end of the reciprocating part (1) is connected to the inner wall of the limiting cylinder (11), and the other end of the reciprocating part (1) is a free end. The free end is used to push and pull the moving parts so that the moving parts can move linearly or deflect. The rotating drive (6) and the fixed drive (7) constitute an external rotor motor. The external rotor motor is used to drive the rotating part (2) to rotate, and then drive the reciprocating part (1) to extend and retract on the limiting cylinder (11).

2. The push rod based on an external rotor rotary motor and a lead screw pair according to claim 1, characterized in that, It also includes a transmission sleeve (5), and the rotation drive (6) is connected to the outer wall of the rotating part (2) through the transmission sleeve (5).

3. The push rod based on an external rotor rotary motor and a lead screw pair according to claim 1, characterized in that, It also includes a cover (3) and a first rotating support (4). One end of the rotating member (2) is connected to the cover (3) through the first rotating support (4), and the rotating member (2) can rotate inside the cover (3).

4. The push rod based on an external rotor rotary motor and a lead screw pair according to claim 2, characterized in that, The limiting cylinder (11) includes a first connecting part (111).

5. The push rod based on an external rotor rotary motor and a lead screw pair according to claim 4, characterized in that, It also includes a second rotating support (8), the inner ring of which is connected to the first connecting part (111), and the outer ring of which is connected to one end of the transmission sleeve (5).

6. The push rod based on an external rotor rotary motor and a lead screw pair according to claim 4, characterized in that, The limiting cylinder (11) also includes a second connecting part (112), and the fixed driving member (7) is disposed on the outer wall of the second connecting part (112).

7. The push rod based on an external rotor rotary motor and a lead screw pair according to claim 4, characterized in that, It also includes an end cap (9), which is connected to the first connecting part (111).

8. The push rod based on an external rotor rotary motor and a lead screw pair according to claim 4, characterized in that, The reciprocating component (1) includes a first reciprocating part (101) for connecting with the rotating component (2).

9. The push rod based on an external rotor rotary motor and a lead screw pair according to claim 8, characterized in that, The reciprocating component (1) also includes a second reciprocating part (102), which is provided with an anti-rotation block.

10. The push rod based on an external rotor rotary motor and a lead screw pair according to claim 9, characterized in that, The limiting cylinder (11) also includes a fixing groove (113), which is provided on the inner wall of the first connecting part (111). The anti-rotation block can be connected to the fixing groove (113) and can slide on the fixing groove (113) to prevent the reciprocating part (1) from rotating.

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