CN218598748U

CN218598748U - Lead screw actuator

Info

Publication number: CN218598748U
Application number: CN202222650044.1U
Authority: CN
Inventors: 王晓成
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2022-10-09
Filing date: 2022-10-09
Publication date: 2023-03-10
Anticipated expiration: 2032-10-09
Also published as: DE102023121669A1

Abstract

The present disclosure relates to a lead screw actuator comprising: a fixed seat; the main shaft is arranged on the fixed seat and can rotate around the axis of the main shaft relative to the fixed seat; the nut is sleeved on the main shaft and is driven to linearly move along the axial direction of the main shaft when the main shaft rotates; the shell is relatively fixed with the position of the fixed seat; and the anti-rotation mechanism is positioned between the shell and the nut and comprises a sliding block and a sliding groove extending along the axial direction, the sliding block is positioned in the sliding groove, and the sliding block is in rolling contact with the sliding groove along the radial direction of the main shaft. The sliding block is in rolling contact with the sliding groove, so that overlarge gap between the sliding block and the sliding groove can be avoided, and the power transmission precision of the lead screw actuator is improved; the friction force between the sliding block and the inner wall of the sliding groove can be reduced, so that the mutual damage between the sliding block and the inner wall of the sliding groove is avoided, and the service life is prolonged.

Description

Lead screw actuator

Technical Field

The utility model relates to a mechanical transmission technical field especially relates to a lead screw actuator.

Background

A lead screw actuator is a linear actuator that converts rotational motion, for example from an electric motor, into linear motion. The screw actuator may include a ball screw actuator including a main shaft (or called a spindle) having an external thread, a nut having an internal thread, and a plurality of balls. A plurality of balls radially separate the spindle from the nut and allow relative rotation between the spindle and the nut with minimal resistance. In some ball screw actuators, the spindle rotates, causing the nut to move axially. In other ball screw actuators, the nut rotates, causing the spindle to move axially.

However, in the ball screw in which the spindle rotates and the nut moves axially, the rotation of the spindle tends to cause circumferential rotation of the nut, resulting in a decrease in the accuracy of the linear motion of the motor.

SUMMERY OF THE UTILITY MODEL

To overcome the problems in the related art, the present disclosure provides a lead screw actuator.

According to a first aspect of embodiments of the present disclosure, the present disclosure provides a lead screw actuator including: a fixed seat; the main shaft is arranged on the fixed seat and can rotate around the axis of the main shaft relative to the fixed seat; the nut is sleeved on the main shaft and is driven to linearly move along the axial direction of the main shaft when the main shaft rotates; the shell is relatively fixed with the position of the fixed seat; and the anti-rotation mechanism is positioned between the shell and the nut and comprises a sliding block and a sliding groove extending along the axial direction, the sliding block is positioned in the sliding groove, and the sliding block is in rolling contact with the sliding groove along the radial direction of the main shaft.

In some embodiments, the slider is provided with a rolling bearing, the axis of which is perpendicular to the axis of the spindle; the outer ring of the rolling bearing is abutted to the sliding groove, and the inner ring of the rolling bearing is fixed with the shell and/or the nut.

In some embodiments, a groove is formed in the inner wall of the sliding groove at the position where the sliding groove abuts against the sliding block, the anti-rotation mechanism further comprises a friction strip, the friction strip is fixed in the groove, and the outer wall of the friction strip protrudes out of the inner wall of the sliding groove and abuts against the sliding block.

In some embodiments, the sliding groove is disposed on the housing, and the sliding block is disposed on the nut; and/or the sliding groove is arranged on the nut, and the sliding block is arranged on the shell.

In some embodiments, the rotation preventing mechanism is provided in at least two and symmetrically arranged along the circumference of the main shaft.

In some embodiments, the anti-rotation mechanism includes a plurality of the sliding blocks, and the plurality of the sliding blocks are arranged at intervals along the axial direction of the main shaft.

In some embodiments, the housing is integrally formed from a metallic material by extrusion.

In some embodiments, the housing has a length in an axial direction along the spindle that is greater than or equal to a length of the spindle.

In some embodiments, the housing is fixed to the holder.

In some embodiments, the lead screw actuator further includes a motor fixed to the fixing base and in transmission connection with one end of the spindle to drive the spindle to rotate.

The technical scheme provided by the embodiment of the disclosure can have the following beneficial effects: the sliding block is in rolling contact with the sliding groove, so that the phenomenon that the gap between the sliding block and the sliding groove is too large can be avoided, and the power transmission precision of the lead screw actuator is improved; the friction force between the sliding block and the inner wall of the sliding groove can be reduced, so that mutual damage between the sliding block and the inner wall of the sliding groove is avoided, and the service life is prolonged.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure.

FIG. 1 is a transverse cross-sectional view of a ball screw actuator shown in accordance with an exemplary embodiment.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

In the present invention, unless otherwise specified, the axial direction a, the radial direction R, and the circumferential direction W refer to the axial direction a, the radial direction R, and the circumferential direction W of the main shaft 10, respectively; in addition, "drive-coupled" means that a driving force/torque can be transmitted between two members, and the two members can be directly connected or can be connected through various transmission mechanisms or connection structures to realize the functions.

The ball screw is provided with an anti-rotation mechanism which can prevent the nut of the ball screw from rotating relative to the main shaft, so that the nut can perform linear motion along the axial direction of the main shaft. In the related art, the rotation preventing mechanism may be implemented by using a sliding key, for example, a nut groove is formed in a housing of the nut, a sliding key extending in the axial direction of the spindle is externally provided, the sliding key is provided with a sliding rail, the nut groove of the nut is matched with the sliding rail of the sliding key, and when the spindle drives the nut in a rotating manner, the nut groove and the sliding rail can prevent the nut from rotating along with the spindle, so that the nut can perform a linear motion in the axial direction of the spindle.

Or, anti-rotation mechanism can adopt the mode of slip table, and the slip table includes slider and slide rail, and the slide rail extends along the axial of main shaft, and the slider can be along the axial displacement of slide rail, and the shell and the slider of nut are fixed, consequently, when initiative rotary drive nut, the slider and the slide rail cooperation of slip table, and the slider is fixed with the shell of nut, can prevent that the nut from rotating along with the main shaft for the nut can carry out linear motion along the axial of main shaft.

However, using a sliding key or slider increases the number of parts and weight of the lead screw actuator. In addition, the sliding key cannot be stably installed with a fixed seat of the lead screw actuator, the installation process difficulty is high, the gap between the nut groove and the sliding rail is large due to process limitation, and the overlarge gap not only increases the accuracy of linear movement of the nut, but also increases the abrasion degree of the nut groove and the sliding rail; the use of a slider also increases the complexity and cost of incorporating the slide into the lead screw actuator system.

In order to solve the above technical problem, the present disclosure provides a lead screw actuator, as shown in fig. 1, the lead screw actuator includes a fixing base (not shown), a spindle 10, a nut 20, a housing 30, an anti-rotation mechanism 40, and a motor (not shown).

Wherein, the motor is fixed on the fixed seat and is connected with one end of the main shaft 10 in a transmission way, so as to drive the main shaft 10 to rotate. At least one end of the main shaft 10 is mounted on the fixed seat, and the main shaft 10 is driven by the motor to rotate, so that the main shaft 10 can rotate around the axis of the main shaft 10 relative to the fixed seat, but the main shaft 10 cannot move or move relative to the fixed seat along the axial direction a.

The nut 20 is sleeved on the main shaft 10, the main shaft 10 is provided with an external thread, the nut 20 is provided with an internal thread, and in some embodiments, a plurality of balls are further arranged between the external thread and the internal thread of the main shaft 10, so that when the main shaft 10 rotates, the main shaft 10 can drive the nut 20 to make a linear motion relative to the main shaft 10 along an axial direction a of the main shaft 10.

Further, the position of the housing 30 and the fixed seat is relatively fixed, i.e. there is no relative movement between the housing 30 and the fixed seat in the axial direction a, the radial direction R and the circumferential direction W. In some embodiments, the housing 30 may be fixed to a device external to the holder to maintain the housing 30 fixed relative to the holder, while in other embodiments, the housing 30 may also be fixed to the holder. Therefore, the whole lead screw actuator is simple in structure and small in occupied space.

The anti-rotation mechanism 40 is located between the housing 30 and the nut 20, and along the radial direction R of the main shaft 10, two ends of the anti-rotation mechanism 40 are respectively abutted to the housing 30 and the nut 20, and because the housing 30 and the fixing seat are fixed in relative position, the anti-rotation mechanism 40 can prevent the nut 20 from rotating along the circumferential direction W of the main shaft 10, and when the main shaft 10 drives the nut 20, the nut 20 can be ensured to always keep moving linearly along the axial direction a of the main shaft 10 relative to the main shaft 10, the housing 30 and the fixing seat.

Further, the length of the housing 30 in the axial direction a of the spindle 10 is greater than or equal to the length of the spindle 10, so that the housing 30 can always provide the nut 20 with a force preventing rotation in the circumferential direction W within the length range of the axial direction a of the spindle 10, so as to ensure that the nut 20 can always move linearly in the axial direction a of the spindle 10.

Further, the anti-rotation mechanism 40 includes a sliding block 41 and a sliding slot 42 extending along the axial direction a, the sliding block 41 is located in the sliding slot 42, specifically, the sliding slot 42 is a slot extending along the axial direction a of the main shaft 10, the sliding block 41 is located in the sliding slot 42, so that the sliding block 41 can move relatively along the sliding slot 42, further, in the radial direction R of the main shaft 10, the sliding block 41 is in rolling contact with the sliding slot 42, so that the sliding slot 42 is used for limiting the circumferential W or radial R movement of the sliding block 41, and therefore, the anti-rotation mechanism 40 formed by combining the sliding block 41 and the sliding slot 42 can enable the nut 20 to move linearly along the axial direction a of the main shaft 10 all the time.

In addition, the sliding block 41 is in rolling contact with the sliding groove 42, so that the sliding block 41 is ensured to be in contact with the inner wall of the sliding groove 42 as much as possible, the overlarge gap between the sliding block 41 and the sliding groove 42 is avoided, and the power transmission precision of the lead screw actuator is increased; in addition, the sliding block 41 is in rolling contact with the sliding groove 42, so that the friction force between the sliding block 41 and the inner wall of the sliding groove 42 can be reduced, mutual damage between the sliding block 41 and the sliding groove is avoided, and the service life is prolonged.

In some embodiments, the slider 41 is provided with a rolling bearing 411, the axis of the rolling bearing 411 being perpendicular to the axis of the spindle 10; wherein, the outer ring of antifriction bearing 411 and spout 42 butt, and the inner ring of antifriction bearing 411 is fixed with casing 30 and/or nut 20.

As shown in fig. 1, when the sliding groove 42 is disposed in the housing 30, an inner ring of the rolling bearing 411 is fixedly connected to the nut 20 through a bolt, the sliding groove 42 is a groove extending along an axial direction a of the main shaft 10, an outer ring of the rolling bearing 411 abuts against two sides of the sliding groove 42 along a radial direction R, when the main shaft 10 rotates to drive the nut 20 to move, the rolling bearing 411 and the sliding groove 42 enable the nut 20 to make a linear motion along an axis of the main shaft 10, the nut 20 drives the rolling bearing 411 to move relatively along the sliding groove 42, and when the rolling bearing 411 moves, the outer ring of the rolling bearing 411 rolls relative to an inner wall of the sliding groove 42, so as to achieve rolling abutment between the slider 41 and the sliding groove 42.

When the sliding groove 42 is disposed on the nut 20, the inner ring of the rolling bearing 411 is fixedly connected with the inner wall of the housing 30 through the bolt 412, and at this time, in some embodiments, the anti-rotation mechanism 40 includes a plurality of sliding blocks 41, and the plurality of sliding blocks 41 are disposed at intervals along the axial direction a of the spindle 10. That is, in the axial direction along the main shaft 10, the inner wall of the housing 30 may be provided with a plurality of rolling bearings 411; the sliding slot 42 of the nut 20 penetrates through the nut 20 along the axial direction a, and when the spindle 10 drives the nut 20 to move, the sliding slot 42 of the nut 20 slides over the outer ring of the rolling bearing 411 on the inner wall of the housing 30, so that the outer ring of the rolling bearing 411 rotates, and the sliding block 41 is in rolling contact with the sliding slot 42.

Use antifriction bearing 411 as slider 41, can make antifriction bearing 411 all the time with the inner wall butt of spout 42 on radial R, can avoid the clearance between slider 41 and the spout 42 too big, in addition, antifriction bearing 411's inner circle passes through bolt 412 and nut 20 fixed connection, assembly methods is simple, in some embodiments, inner circle and bolt 412 can be the integrated into one piece structure, in addition, antifriction bearing 411 can reduce the frictional force with the inner wall of spout 42 between to avoid the mutual damage between the two, increase of service life.

In some embodiments, the inner wall of the sliding slot 42 is provided with a groove 43 at the abutting position with the sliding block 41, the anti-rotation mechanism 40 further includes a friction bar 44, the friction bar 44 is fixed in the groove 43, and the outer wall of the friction bar 44 protrudes from the inner wall of the sliding slot 42 and abuts with the sliding block 41.

The friction strip 44 is a steel wire or steel bar which is subjected to heat treatment, has high hardness and is anti-friction, and the friction strip 44 is arranged in the groove 43, and the outer wall of the friction strip 44 protrudes out of the inner wall of the sliding groove 42, so that the friction strip 44 is abutted with the outer ring of the rolling bearing 411, namely the outer ring of the rolling bearing 411 is abutted with the outer wall of the friction strip 44 in a rolling manner, and the outer ring of the rolling bearing 411 is prevented from being directly abutted with the inner wall of the sliding groove 42 in a rolling manner to damage the inner wall of the sliding groove 42; in addition, the rubbing strip 44 is easy to replace and can be replaced repeatedly, so that the shell 30 is prevented from being replaced repeatedly, and the cost is reduced.

In some embodiments, the housing 30 is integrally formed from a metallic material by extrusion. Specifically, the housing 30 may be produced by an aluminum extrusion method. The extrusion process can produce hollow or solid products with complicated cross-sectional shapes, for example, in the present embodiment, when the sliding groove 42 is disposed in the housing 30, the sliding groove 42 and the groove 43 structure located in the sliding groove 42 can be directly formed integrally by aluminum extrusion, without rolling or die forging, which results in low process difficulty, fewer production steps and low cost.

In addition, the extruded product has much higher dimensional accuracy than a rolled or die-forged product, has good surface roughness, can be processed without or even with little processing, is directly called a finished product after extrusion molding, and has higher longitudinal performance than the rolled or die-forged product due to the extrusion effect.

In some embodiments, the sliding groove 42 is disposed on the housing 30, and the sliding block 41 is disposed on the nut 20 at this time, that is, the sliding block 41 is fixedly connected to the nut 20; and/or the sliding groove 42 is arranged on the nut 20, and the sliding block 41 is arranged on the shell 30, namely, the sliding block 41 is fixedly connected with the shell 30.

In other embodiments, the anti-rotation mechanisms 40 are provided in at least two and are symmetrically arranged along the circumferential direction W of the main shaft 10. Thus, the plurality of anti-rotation mechanisms 40 may be configured in the same configuration or in different configurations. For example, when the anti-rotation mechanism 40 is provided in two, one of the anti-rotation mechanisms 40 may be configured such that the slide groove 42 is provided to the housing 30 and the slider 41 is provided to the nut 20; another anti-rotation mechanism 40 may be configured with a slide slot 42 provided to the nut 20 and a slider 41 provided to the housing 30.

In addition, as shown in fig. 1, in the present embodiment, the housing 30 may have a square sleeve shape, and is covered on the outer portions of the main shaft 10 and the nut 20. The rotation preventing mechanism 40 may be provided above and below as shown in fig. 1, may be provided on the left and right as shown in fig. 1, or may be provided on the upper left and lower right or upper right and lower left as shown in fig. 1.

Similarly, in other embodiments, the anti-rotation mechanism 40 may be disposed non-centrosymmetrically, and may be disposed axisymmetrically or non-axisymmetrically along the axis of the spindle 10, so that it is understood that the anti-rotation mechanism 40 may be disposed at any position along the circumferential direction W of the spindle 10.

In other embodiments, when the anti-rotation mechanism 40 is disposed on the left and right in fig. 1, the housing 30 may further include two separate housings 30 disposed on two sides of the main shaft 10 in the radial direction R of the main shaft 10, and each housing 30 is fixed relative to the fixed seat, or each housing 30 is fixed to the fixed seat.

It is understood that "a plurality" in this disclosure means two or more, and other words are analogous. "and/or" describes the association relationship of the associated object, indicating that there may be three relationships, for example, a and/or B, which may indicate: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. The singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It will be further understood that the terms "first," "second," and the like are used to describe various structures, but these structures should not be limited by these terms. These terms are only used to distinguish one type of structure from another and do not denote a particular order or importance. Indeed, the terms "first," "second," etc. are used interchangeably throughout. For example, a first structure could also be termed a second structure, and, similarly, a second structure could also be termed a first structure, without departing from the scope of the present disclosure.

It will be further understood that the terms "central," "longitudinal," "lateral," "front," "rear," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for convenience in describing the present embodiment and to simplify the description, but do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation.

It will be further understood that, unless otherwise specified, "connected" includes direct connections between the two without the presence of other elements, as well as indirect connections between the two with the presence of other elements.

It will be further appreciated that while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in serial order, or that all illustrated operations be performed, to achieve desirable results. In certain environments, multitasking and parallel processing may be advantageous.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice in the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It will be understood that the present disclosure is not limited to the precise arrangements that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is to be limited only by the scope of the appended claims.

Claims

1. A lead screw actuator, comprising:

a fixed seat;

the main shaft (10) is mounted on the fixed seat, and the main shaft (10) can rotate around the axis of the main shaft (10) relative to the fixed seat;

the nut (20) is sleeved on the main shaft (10), and when the main shaft (10) rotates, the nut (20) is driven to linearly move along the axial direction (A) of the main shaft (10);

the shell (30) is fixed relative to the position of the fixed seat; and

an anti-rotation mechanism (40) located between the housing (30) and the nut (20), the anti-rotation mechanism (40) comprising a slide block (41) and a slide slot (42) extending in the axial direction (A), the slide block (41) being located within the slide slot (42),

wherein, along the radial direction (R) of the main shaft (10), the sliding block (41) is in rolling contact with the sliding groove (42).

2. Lead screw actuator according to claim 1,

the sliding block (41) is provided with a rolling bearing, and the axis of the rolling bearing is vertical to the axis of the main shaft (10);

the outer ring of the rolling bearing is abutted against the sliding groove (42), and the inner ring of the rolling bearing is fixed with the shell (30) and/or the nut (20).

3. Lead screw actuator according to claim 1,

the inner wall of the sliding groove (42) is provided with a groove (43) at the abutting part of the sliding block (41),

the anti-rotation mechanism (40) further comprises a friction strip (44), the friction strip (44) is fixed in the groove (43), and the outer wall of the friction strip (44) protrudes out of the inner wall of the sliding groove (42) and is abutted to the sliding block (41).

4. Lead screw actuator according to claim 1,

the sliding groove (42) is arranged on the shell (30), and the sliding block (41) is arranged on the nut (20); and/or

The sliding groove (42) is arranged on the nut (20), and the sliding block (41) is arranged on the shell (30).

5. Lead screw actuator according to claim 1,

the anti-rotation mechanisms (40) are arranged in at least two numbers and are symmetrically arranged along the circumferential direction (W) of the main shaft (10).

6. Lead screw actuator according to claim 1,

the anti-rotation mechanism (40) comprises a plurality of sliding blocks (41), and the sliding blocks (41) are arranged at intervals along the axial direction (A) of the spindle (10).

7. Lead screw actuator according to claim 1,

the housing (30) is integrally formed of a metal material by an extrusion method.

8. Lead screw actuator according to claim 1,

the length of the housing (30) in the axial direction (A) of the spindle (10) is greater than or equal to the length of the spindle (10).

9. Lead screw actuator according to claim 1,

the shell (30) is fixed on the fixed seat.

10. Lead screw actuator according to claim 1,

the lead screw actuator further comprises a motor, wherein the motor is fixed on the fixed seat and is in transmission connection with one end of the main shaft (10) so as to drive the main shaft (10) to rotate.