Electric screw drive

Abstract

The utility model relates to an electric screw rod, including drive assembly and screw rod subassembly. Drive assembly includes motor. The motor includes first shell and pivot. Screw rod subassembly includes second shell, screw rod axle, screw rod nut and limit block. Screw rod nut is same coaxial sleeve and is established on screw rod axle with pivot transmission connection. The one end of screw rod axle is same coaxial thread connection with screw rod nut, and the other end of screw rod axle passes out second chamber. The limit step is formed on the circumferential side of screw rod axle along the radial direction of screw rod axle and protrudes. The guide groove is set up on the limit step. The guide protrusion is set up on the limit block, and the guide protrusion extends along the axial direction of screw rod axle. The limit block is embedded in the guide groove, and can slip along the axial direction of screw rod axle in the guide groove. The utility model avoids the restriction of the diameter of motor pivot to the diameter of screw rod axle, and compared with the prior art electric screw rod, is suitable for screw rod axle of multiple diameters. When replacing screw rod axle, the second shell can be detached from the first shell, the screw rod subassembly is replaced as a whole, and the assembly and disassembly are convenient.

Description

Technical Field

[0001] This utility model relates to the technical field of electric lead screws, and in particular to an electric lead screw. Background Technology

[0002] An electric lead screw is an actuator that converts the rotary motion of a motor into linear motion, enabling high-precision linear positioning. Its core components include a drive motor, a lead screw, connecting parts, and supporting components. The motor typically uses a stepper motor, servo motor, or DC motor, while the lead screw is usually a ball screw or trapezoidal lead screw. Currently, lead screw motor assemblies are widely used, for example in industrial robots, automated production line equipment, aerospace drive mechanisms, and medical equipment.

[0003] In the existing technology, when the diameter of the electric lead screw is small, the nut at the end of the lead screw can be placed inside the hollow shaft of the motor to realize the transmission between the motor and the lead screw. However, when the diameter is large, it will be difficult to place the end of the lead screw into the motor shaft. Therefore, there is an urgent need for an electric lead screw that is suitable for lead screws with larger diameters. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides an electric lead screw.

[0005] The technical solution provided by this utility model is as follows:

[0006] An electric lead screw includes a drive assembly and a lead screw assembly; wherein the drive assembly includes a motor; the motor includes a first housing and a rotating shaft; a second housing is detachably connected to the first housing; the first housing has a first chamber; the rotating shaft is rotatably disposed within the first chamber; the lead screw assembly includes a second housing, a lead screw shaft, a lead screw nut, and a limiting block; the second housing has a second chamber; the second chamber communicates with the first chamber; the lead screw nut is drively connected to the rotating shaft and coaxially sleeved on the lead screw shaft; the lead screw shaft... One end of the screw is coaxially threaded to the lead screw nut to convert the rotation of the lead screw nut into the axial movement of the lead screw shaft. The other end of the lead screw shaft passes through the second chamber. A limiting step is formed by a radial protrusion on the circumference of the lead screw shaft. A guide groove is provided on the limiting step. The limiting block is fixedly disposed in the second chamber and has a guide protrusion thereon. The guide protrusion extends along the axial direction of the lead screw shaft. The guide protrusion is embedded in the guide groove and can slide along the axial direction of the lead screw shaft within the guide groove.

[0007] Optionally, the lead screw nut includes a nut body and a nut bracket; the nut bracket is disposed in the second chamber, detachably connected to the rotating shaft, and coaxial with the rotating shaft; the nut body is detachably connected to the nut bracket.

[0008] Optionally, the nut bracket has a waist-shaped groove on the side opposite to the motor; the bottom wall of the waist-shaped groove has a mounting hole coaxially formed with the nut bracket to provide mounting space for the nut body; one end of the nut body is formed with a mounting cap; the shape of the mounting cap is adapted to the shape of the waist-shaped groove so that when the nut body is installed with the nut bracket, the mounting cap can be embedded in the waist-shaped groove.

[0009] Optionally, the circumference of the nut bracket is supported on the inner wall of the second chamber by a bearing and slides in contact with the inner wall of the second chamber.

[0010] Optionally, there are multiple guide grooves, which are evenly spaced around the axis of the lead screw shaft on the limiting step; there are multiple guide protrusions, and each guide protrusion corresponds to one of the guide grooves.

[0011] Optionally, the two ends of the lead screw shaft are threaded ends and unthreaded ends, respectively; the threaded end is threadedly engaged with the lead screw nut; a bushing is provided at the point where the lead screw shaft passes through the second housing; the unthreaded end is slidably engaged with the bushing.

[0012] Optionally, a sealing ring is provided between the bushing and the lead screw shaft.

[0013] Optionally, the end of the rotating shaft near the lead screw shaft is coaxially provided with a receiving hole; when the lead screw shaft moves along its axial direction, the end of it that is threadedly connected to the lead screw nut can be partially retracted into the receiving hole.

[0014] As described above, the electric lead screw of this invention has at least the following beneficial effects:

[0015] This invention relates to an electric lead screw that uses a lead screw nut fitted onto the outside of the motor shaft. The transmission between the shaft and the lead screw nut is achieved through a detachable connection. The rotation of the lead screw nut is converted into movement of the lead screw shaft along its axial direction through the threaded engagement between the lead screw shaft and the lead screw nut, as well as the guiding and limiting functions of the guide groove and guide protrusion, thus realizing the extension and retraction of the lead screw shaft. The structure adopted in this invention avoids the limitation of the motor shaft diameter on the lead screw shaft diameter, and compared with existing electric lead screws, it can be used with lead screw shafts of various diameters. When replacing the lead screw shaft, the second outer casing can be removed from the first outer casing, allowing for the replacement of the entire lead screw assembly, making disassembly and assembly convenient. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the electric lead screw.

[0017] Figure 2 This is a half-section view of the overall structure of the electric lead screw.

[0018] Figure 3 This is a schematic diagram of the lead screw shaft structure.

[0019] Figure 4 This is a schematic diagram of the nut bracket structure.

[0020] Figure 5 This is a schematic diagram of the nut body structure.

[0021] Figure 6 This is a schematic diagram of the limit block structure.

[0022] Reference numerals: 1. Drive assembly; 2. Lead screw assembly; 3. Flat key; 4. Rotary shaft; 41. Receiving hole; 5. Lead screw shaft; 6. Nut body; 61. Mounting cap; 7. Nut bracket; 71. Waist groove; 72. Mounting hole; 8. Limiting block; 81. Guide protrusion; 9. Second housing; 10. Sealing ring; 11. Bushing; 12. Threaded end; 13. Non-threaded end; 14. Limiting step; 141. Guide groove; 15. First housing; 16. Bearing. Detailed Implementation

[0023] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. It should also be understood that the terminology used in the embodiments of this utility model is for describing specific implementation schemes and not for limiting the scope of protection of this utility model. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0024] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of implementation of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this utility model, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation of this utility model.

[0025] Please refer to Figures 1-6 This utility model discloses an electric lead screw, including a drive assembly 1 and a lead screw assembly 2. The drive assembly 1 includes a motor, which includes a first housing 15 and a rotating shaft 4. The first housing 15 has a first chamber, and the rotating shaft 4 is rotatably disposed in the first chamber. The lead screw assembly 2 includes a second housing 9, a lead screw shaft 5, a lead screw nut, and a limiting block 8. The second housing 9 is detachably connected to the first housing 15. The second housing 9 has a second chamber, which communicates with the first chamber. The lead screw nut is drivenly connected to the rotating shaft 4 and is coaxially sleeved 11 on the lead screw shaft 5. One end of the lead screw shaft 5 is coaxially threaded to the lead screw nut to convert the rotation of the lead screw nut into the axial movement of the lead screw shaft 5. The other end of the lead screw shaft 5 extends out of the second chamber. A limiting step 14 is formed by a radial protrusion on the circumference of the lead screw shaft 5. A guide groove 141 is provided on the limiting step 14. The limiting block 8 is fixedly disposed in the second chamber, and a guide protrusion 81 is provided on it, which extends along the axial direction of the lead screw shaft 5. The limiting block 8 is embedded in the guide groove 141 and can slide within the guide groove 141 along the axial direction of the lead screw shaft 5.

[0026] For details, please refer to Figure 1 The motor can be of various types, such as stepper motors and servo motors. In this embodiment, a stepper motor is used. The end face of the second housing 9 near the first housing 15 mates with the stop on the first housing 15, and then bolts are used to fix the second housing 9 to the first housing 15.

[0027] The lead screw nut can be directly coaxially fixed or detachably connected to the rotating shaft 4, thereby realizing the conversion of the rotating shaft 4 to the movement of the lead screw shaft 5. However, in order to ensure the stability of the lead screw assembly 2 during operation, in a preferred embodiment of this utility model, the lead screw nut includes a nut body 6 and a nut bracket 7.

[0028] Please refer to Figures 2-5 The nut bracket 7 is located in the second chamber and is detachably connected to the rotating shaft 4, and is coaxial with the rotating shaft 4. The nut body 6 is detachably connected to the nut bracket 7.

[0029] The nut bracket 7 is cylindrical in shape, with a slot 71 on the side facing away from the motor. A mounting hole 72, coaxial with the nut bracket 7, is formed on the bottom wall of the slot 71, providing mounting space for the nut body 6. The nut body 6 is bolt-like in shape, with a threaded hole in the center, and a mounting cap 61 formed at one end. The shape of the mounting cap 61 matches the shape of the slot 71, allowing it to be inserted into the slot 71 when the nut body 6 is assembled with the nut bracket 7. After the mounting cap 61 is inserted into the slot 71, the nut body 6 and the nut bracket 7 can be further secured with bolts. The thickness of the mounting cap 61 is less than or equal to the depth of the slot 71, ensuring that the mounting cap 61 does not protrude from the slot 71 after assembly. The special shapes of the mounting cap 61 and the slot 71 prevent relative rotation between the nut body 6 and the nut bracket 7. It is easy to imagine that the shape of the waist-shaped groove 71 can also be changed to various polygons or other shapes that can prevent relative rotation between the nut body 6 and the nut bracket 7, and the shape of the mounting cap 61 can also be changed accordingly.

[0030] The detachable connection between the nut bracket 7 and the rotating shaft 4 can be a keyway connection, a pin connection, etc. In this embodiment, the nut bracket 7 and the rotating shaft 4 are connected by a keyway. Specifically, the end of the rotating shaft 4 passes through a mounting hole 72, and a flat key 3 is formed on the inner wall of the opening of the mounting hole 72 near the rotating shaft 4. Correspondingly, a keyway is provided on the end of the rotating shaft 4. Through the mutual cooperation of the flat key 3 and the keyway, the rotating shaft 4 can drive the nut bracket 7 to rotate.

[0031] In a preferred embodiment of this invention, the circumference of the nut bracket 7 is supported on the inner wall of the second chamber by a bearing 16, and slides against the inner wall of the second chamber. The axis of the bearing 16 coincides with the rotation axis of the nut bracket 7. The outer ring of the bearing 16 is detachably connected to the inner wall of the second chamber. The inner ring is fitted onto the circumference of the nut bracket 7. This prevents the axis of the nut bracket 7 from shifting during rotation and improves the smoothness of rotation of the nut bracket 7.

[0032] Please refer to Figure 2 , Figure 3 The lead screw shaft 5 has a threaded end 12 and a non-threaded end 13 at its two ends. The threaded end 12 is threaded into the lead screw nut. To ensure that the axis of the lead screw shaft 5 does not deviate when rotating, a bushing 11 is provided at the point where the lead screw shaft 5 passes through the second housing 9. A sealing ring 10 is also provided between the bushing 11 and the lead screw shaft 5 to prevent dust, oil, water, etc. from entering the second chamber through the gap between the bushing 11 and the lead screw shaft 5. The non-threaded end 13 is slidably engaged with the bushing 11. When the lead screw nut rotates, due to the engagement of the guide protrusion 81 and the guide groove 141, the lead screw shaft 5 cannot rotate and will only move along its own axis.

[0033] The shape of limit block 8 is as follows Figure 6 As shown, it is cylindrical in shape, with a through hole in the center for the lead screw shaft 5 to pass through, and a guide protrusion 81 is provided on the inner wall of the through hole. Several countersunk holes are evenly spaced around the axis of the limiting block 8 on one side of the limiting block 8 for installing bolts to fix the limiting block 8 to the inner wall of the second chamber.

[0034] To enhance the limiting and guiding functions of the limiting step 14 and the guide groove 141, multiple guide grooves 141 are provided, evenly spaced around the axis of the lead screw shaft 5 on the limiting step 14. The number of guide protrusions 81 is the same as the number of guide grooves 141 and corresponds one-to-one. In this embodiment, there are two guide grooves 141, located at opposite ends of a diameter of the limiting step 14. Correspondingly, there are also two guide protrusions 81, located at opposite ends of a diameter of the limiting block 8.

[0035] Please refer to Figure 2 To reduce the space occupied by the electric lead screw, a receiving hole 41 is coaxially provided at one end of the shaft 4 near the lead screw shaft 5, provided that the diameter and mechanical strength of the shaft 4 allow it. When the lead screw shaft 5 moves along its axial direction, the end of it that is threadedly connected to the lead screw nut can be partially retracted into the receiving hole 41.

[0036] This invention relates to an electric lead screw that achieves transmission between the motor shaft 4 and the lead screw nut by fitting a lead screw nut onto the outside of the motor shaft 4 through a detachable connection. The rotation of the lead screw nut is converted into movement of the lead screw shaft 5 along its axial direction through the threaded engagement between the lead screw shaft 5 and the lead screw nut, as well as the guiding and limiting functions of the guide groove 141 and the guide protrusion 81, thus realizing the extension and retraction of the lead screw shaft 5. The structure adopted in this invention avoids the limitation of the motor shaft 4's diameter on the lead screw shaft 5's diameter, and compared with existing electric lead screws, it can be used with lead screw shafts 5 of various diameters. When replacing the lead screw shaft 5, the second outer casing 9 can be removed from the first outer casing 15, allowing for the replacement of the entire lead screw assembly, making disassembly and assembly convenient.

[0037] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. An electric lead screw, characterized in that, It includes a drive assembly (1) and a lead screw assembly (2); wherein, The drive assembly (1) includes a motor; the motor includes a first housing (15) and a rotating shaft (4); the first housing (15) has a first chamber; the rotating shaft (4) is rotatably disposed within the first chamber; The lead screw assembly (2) includes a second housing (9), a lead screw shaft (5), a lead screw nut, and a limiting block (8); The second outer shell (9) is detachably connected to the first outer shell (15); the second outer shell (9) has a second chamber; the second chamber communicates with the first chamber; the lead screw nut is connected to the rotating shaft (4) and is coaxially sleeved (11) on the lead screw shaft (5); One end of the lead screw shaft (5) is coaxially threaded to the lead screw nut to convert the rotation of the lead screw nut into the axial movement of the lead screw shaft (5), and the other end of the lead screw shaft (5) passes through the second chamber; A limiting step (14) is formed on the circumferential side of the lead screw shaft (5) along the radial protrusion of the lead screw shaft (5); a guide groove (141) is provided on the limiting step (14); The limiting block (8) is fixedly disposed in the second chamber, and a guide protrusion (81) is provided thereon. The guide protrusion (81) extends along the axial direction of the lead screw shaft (5). The guide protrusion (81) is embedded in the guide groove (141) and can slide in the guide groove (141) along the axial direction of the lead screw shaft (5).

2. The electric lead screw according to claim 1, characterized in that: The lead screw nut includes a nut body (6) and a nut bracket (7); the nut bracket (7) is disposed in the second chamber, detachably connected to the rotating shaft (4), and coaxial with the rotating shaft (4); The nut body (6) and the nut bracket (7) are detachably connected.

3. The electric lead screw according to claim 2, characterized in that: The nut bracket (7) has a waist-shaped groove (71) on the side away from the motor; The bottom wall of the waist-shaped groove (71) is provided with a mounting hole (72) coaxially with the nut bracket (7) to provide mounting space for the nut body (6); One end of the nut body (6) is formed with a mounting cap (61); the shape of the mounting cap (61) is adapted to the shape of the waist-shaped groove (71) so that when the nut body (6) is installed with the nut bracket (7), the mounting cap (61) can be embedded in the waist-shaped groove (71).

4. The electric lead screw according to claim 3, characterized in that: The circumference of the nut bracket (7) is supported on the inner wall of the second chamber by a bearing (16) and slides in cooperation with the inner wall of the second chamber.

5. The electric lead screw according to claim 1, characterized in that, The number of guide grooves (141) is multiple, and the multiple guide grooves (141) are evenly spaced on the limiting step (14) around the axis of the lead screw shaft (5); The number of guide protrusions (81) is multiple; each guide protrusion (81) corresponds to a guide groove (141).

6. The electric lead screw according to claim 1, characterized in that: The two ends of the lead screw shaft (5) are a threaded end (12) and a non-threaded end (13), respectively; The threaded end (12) is threadedly engaged with the lead screw nut; The second housing (9) has a bushing (11) at the point where the lead screw shaft (5) passes through; the non-threaded end (13) is in sliding engagement with the bushing (11).

7. The electric lead screw according to claim 6, characterized in that: A sealing ring (10) is provided between the bushing (11) and the lead screw shaft (5).

8. The electric lead screw according to claim 1, characterized in that, The rotating shaft (4) has a receiving hole (41) coaxially opened at one end near the lead screw shaft (5); when the lead screw shaft (5) moves along its axial direction, the end of it that is threadedly connected to the lead screw nut can be partially retracted into the receiving hole (41).

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