CN214429403U

CN214429403U - Linear actuator

Info

Publication number: CN214429403U
Application number: CN202120150144.0U
Authority: CN
Inventors: 赵新星
Original assignee: Zhejiang Jiecang Linear Motion Technology Co Ltd
Current assignee: Zhejiang Jiecang Linear Motion Technology Co Ltd
Priority date: 2021-01-20
Filing date: 2021-01-20
Publication date: 2021-10-19
Anticipated expiration: 2031-01-20

Abstract

The utility model discloses a linear actuator belongs to linear actuating technical field, including driving motor and transmission assembly, driving motor includes the motor shaft, the transmission assembly includes worm wheel and lead screw, worm wheel and motor shaft meshing transmission, the worm wheel cover establish on the lead screw and spacing with lead screw circumference, the worm wheel is equipped with the free gap with the spacing department of lead screw circumference, in order to offset the axiality deviation of worm wheel and lead screw, the influence of lead screw axle center skew can offset in the free gap department, can not transmit for the worm wheel, thereby fine assurance worm wheel and motor shaft meshing precision, avoid the production of periodic abnormal sound, improve worm wheel life. And the requirement on the machining precision of the screw rod can be properly reduced, the difficulty in process control is reduced, the qualification rate of part batch production is improved, and the machining cost is reduced.

Description

Linear actuator

[ technical field ] A method for producing a semiconductor device

The utility model relates to a linear actuation technical field, concretely relates to linear actuator.

[ background of the invention ]

Linear actuators are currently used in a wide variety of applications including medical equipment, home and office, solar power generation, and the like. The structure of the linear actuator generally comprises a driving motor, a transmission screw rod, a worm wheel and a transmission nut, wherein the driving motor drives the rotation screw rod to rotate, the transmission nut is driven to axially move when the rotation screw rod rotates, and the transmission nut can be connected with a driving object, so that the driving purpose is realized.

Linear actuator on the existing market, the transmission form mostly adopts worm gear transmission, and the cooperation of worm wheel and lead screw is mostly threaded connection or splined connection, and the worm wheel rotates and produces circumference moment of torsion to transmit circumference moment of torsion through screw thread or spline.

Because the worm wheel is mostly made of plastic materials, the mass production usually adopts an injection molding process, so if the worm wheel is in threaded connection with the screw rod, namely the positioning is carried out by adopting a screwing mode of the internal thread hole and the screw rod, the injection molding precision of the internal thread hole can directly influence the positioning precision of the worm wheel on the transmission screw rod, such as the verticality and the coaxiality of the worm wheel relative to the transmission screw rod, when the verticality and the coaxiality of the worm wheel relative to the transmission screw rod are deviated, the transmission stability of the worm wheel and the worm can be influenced, the worm wheel and the worm are meshed to generate periodic abnormal sounds, the injection molding precision requirement on the worm wheel is higher, the process control difficulty is increased in the mass production, but the consistency of products is difficult to ensure in the mass production; if worm wheel and lead screw adopt splined connection, be mostly the mould product of metal material because of the spline, adopt this middle transition piece of spline to fix a position, the cost can corresponding rising, and spline and transmission lead screw can produce the impact sound between the metal in the twinkling of an eye at linear actuator start-stop, reduce the operator and use the impression.

[ Utility model ] content

The object of the present invention is to design a linear actuator that can solve the technical problems existing in the prior art at least in part.

In order to solve the technical problem, the utility model adopts the following technical scheme:

the linear actuator comprises a driving motor and a transmission assembly, wherein the driving motor comprises a motor shaft, the transmission assembly comprises a worm wheel and a screw rod, the worm wheel is in meshing transmission with the motor shaft, the worm wheel is sleeved on the screw rod and is circumferentially limited with the screw rod, and a movable gap is arranged at the circumferential limiting position of the worm wheel and the screw rod so as to offset coaxiality deviation of the worm wheel and the screw rod.

The beneficial effect of this scheme of adoption:

based on the higher condition of worm wheel requirement of adopting threaded connection to mould plastics between prior art worm wheel and the lead screw, be equipped with the clearance through spacing department in worm wheel and lead screw circumference in this scheme, it is bad because of the machining precision when worm wheel and lead screw, lead to the in-process of actual operation nut and worm wheel's axiality to produce certain deviation, can drive the lead screw skew in the nut operation process, thereby change the axle center of lead screw, if adopt present cooperation inseparable mode, the skew in lead screw axle center can drive the worm wheel and remove, thereby influence worm wheel and worm complex stability, in this scheme, the influence of lead screw axle center skew can offset in clearance department, can not transmit for the worm wheel, thereby fine assurance worm wheel and motor shaft meshing precision, avoid the production of periodic abnormal sound, improve worm wheel life. And the requirement on the machining precision of the screw rod can be properly reduced, the difficulty in process control is reduced, the qualification rate of part batch production is improved, and the machining cost is reduced.

Preferably, the worm wheel is matched with the flat position of the screw rod.

Preferably, the screw rod is provided with a flat position, the worm wheel is provided with a flat hole matched with the flat position, and the flat position is in clearance fit with the flat hole.

Preferably, the flat positions comprise double flat positions, and the flat holes comprise double flat holes.

Preferably, the worm gear further comprises a housing and a bearing, and two ends of the worm gear are positioned in the housing through the bearing.

Preferably, the worm wheel comprises an annular tooth surface in meshing transmission with the motor shaft and a hollow shaft connected with the annular tooth surface, the hollow shaft is sleeved on the screw rod and axially limited with the screw rod, and the bearing comprises a first bearing and a second bearing which are respectively sleeved on the hollow shaft on two sides of the annular tooth surface.

Preferably, the housing is provided with a first annular groove for accommodating the first bearing and a second annular groove for accommodating the second bearing.

Preferably, the first bearing and the second bearing both comprise deep groove ball bearings, the first bearing comprises a first outer ring and a first inner ring, the first inner ring is in interference fit with the hollow shaft, the first outer ring is in clearance fit with the first annular groove, the second bearing comprises a second outer ring and a second inner ring, the second inner ring is in interference fit with the hollow shaft, and the second outer ring is in clearance fit with the second annular groove.

Preferably, the transmission assembly further comprises a guide sleeve fixed relative to the shell, a push rod sleeved in the guide sleeve, and a nut sleeved on the lead screw, the nut is fixedly connected with the push rod, a gasket is arranged in front of the hollow shaft, a buffer ring is arranged at the rear of the hollow shaft, and the buffer ring, the worm wheel, the gasket and the nut are sequentially sleeved on the lead screw from back to front.

Preferably, the front end of the hollow shaft is provided with a first annular step, the first bearing is sleeved on the first annular step, the rear end of the hollow shaft is provided with a second annular step, the buffer ring is provided with a third annular step, the second annular step and the third annular step form a third annular groove, and the second bearing is sleeved in the third annular groove.

These features and advantages of the present invention will be disclosed in more detail in the following detailed description and the accompanying drawings.

[ description of the drawings ]

The utility model is further described with the following drawings:

fig. 1 is a schematic perspective view of the linear actuator of the present invention.

Fig. 2 is a partial cross-sectional view of the linear actuator of the present invention.

Fig. 3 is a schematic view of the local three-dimensional structure of the transmission assembly of the present invention.

Fig. 4 is a schematic view of the three-dimensional structure of the worm wheel of the present invention.

Reference numerals: driving a motor 001; a motor shaft 001 a; a housing 002; the first annular groove 002 a; the second annular groove 002 b; a worm wheel 1; an annular tooth surface 101; a hollow shaft 102; a first annular step 102 a; a second annular step 102 b; a screw rod 2; a flat portion 201; a guide sleeve 3; a push rod 4; a nut 5; a first bearing 6; a second bearing 7; a flat hole 8; a buffer ring 9; a third annular step 901; a gasket 10; a third annular groove 11; the clearance a is movable.

[ detailed description ] embodiments

The technical solutions of the embodiments of the present invention are explained and explained below with reference to the drawings of the embodiments of the present invention, but the embodiments described below are only preferred embodiments of the present invention, and not all embodiments. Based on the embodiments in the embodiment, other embodiments obtained by those skilled in the art without any creative work belong to the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and to simplify the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise specified, "a plurality" means two or more unless explicitly defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Example (b):

as shown in fig. 1 to 4, a linear actuator includes a driving motor 001 and a transmission assembly, the driving motor 001 includes a motor shaft 001a, the transmission assembly includes a worm wheel 1 and a screw rod 2, the worm wheel 1 is engaged with the motor shaft 001a for transmission, the worm wheel 1 is sleeved on the screw rod 2 and circumferentially limited with the screw rod 2, and a movable gap a is arranged at the circumferentially limited position of the worm wheel 1 and the screw rod 2 to offset the coaxiality deviation of the worm wheel 1 and the screw rod 2.

Based on the condition that the requirement on the injection molding precision of the worm wheel 1 is higher by adopting threaded connection between the worm wheel 1 and the screw rod 2 in the prior art, the scheme is characterized in that a movable gap a is arranged at the circumferential limiting position of the worm wheel 1 and the screw rod 2, when the worm wheel 1 and the screw rod 2 have a certain deviation in the coaxiality of the nut 5 and the worm wheel 1 in the actual operation process due to poor processing precision, the screw rod 2 is driven to deviate in the operation process of the nut 5, thereby changing the axis of the screw rod 2, if the existing matching tight mode is adopted, the offset of the axis of the screw rod 2 can drive the worm wheel 1 to move, thereby affecting the stability of the matching of the worm wheel 1 and the worm, in the scheme, the influence of the axle center deviation of the screw rod 2 can be offset at the movable clearance a and can not be transmitted to the worm wheel 1, thereby fine assurance worm wheel 1 and motor shaft 001a meshing precision, avoid the production of periodic abnormal sound, improve worm wheel 1 life. And the requirement on the processing precision of the screw rod 2 can be properly reduced, the difficulty of process control is reduced, the qualification rate of part batch production is improved, and the processing cost is reduced.

As shown in fig. 1 and fig. 2, the linear actuator further includes a housing 002, the transmission assembly further includes a guide sleeve 3 fixed relative to the housing 002, a push rod 4 sleeved in the guide sleeve 3, and a nut 5 sleeved on the lead screw 2, and the nut 5 is fixedly connected with the push rod 4.

In order to ensure that the circumferential torque is effectively transmitted, the worm wheel 1 and the screw rod 2 are matched by using the flat position 201 in the embodiment, specifically, as shown in fig. 3, the flat position 201 is arranged on the screw rod 2, the flat hole 8 matched with the flat position 201 is arranged on the worm wheel 1, and the flat position 201 and the flat hole 8 are in clearance fit, preferably, double flat positions and double flat holes.

In this embodiment, the worm wheel 1 is directly matched with the screw rod 2 to perform circumferential limitation, intermediate transition pieces such as splines are saved, the cost is reduced, metal impact sound generated by the splines and the screw rod 2 in the moment of starting and stopping of the linear actuator is avoided, and the use feeling of an operator is improved.

In this embodiment, the screw rod 2 and the worm wheel 1 adopt the connection structure with the flat position 201 in clearance fit, so that the worm wheel 1 cannot be axially limited by the screw rod 2 or the spline in the prior art, and therefore in this embodiment, at least two bearings are arranged in the housing 002, two ends of the worm wheel 1 are positioned in the housing 002 through the bearings, as shown in fig. 4, the worm wheel 1 includes an annular tooth surface 101 in meshing transmission with the motor shaft 001a and a hollow shaft 102 connected with the annular tooth surface 101, the hollow shaft 102 is sleeved on the screw rod 2 and axially limited with the screw rod 2, the bearings include a first bearing 6 and a second bearing 7 respectively sleeved on the hollow shaft 102 at two sides of the annular tooth surface 101, as shown in fig. 2, the housing 002 is provided with a first annular groove 002a for accommodating the first bearing 6 and a second annular groove 002b for accommodating the second bearing 7, and both the first bearing 6 and the second bearing 7 are preferably deep groove ball bearings, specifically, the first bearing 6 includes a first outer ring and a first inner ring, the first inner ring is in interference fit with the hollow shaft 102, the first outer ring is in clearance fit with the first annular groove 002a, the second bearing 7 includes a second outer ring and a second inner ring, the second inner ring is in interference fit with the hollow shaft 102, and the second outer ring is in clearance fit with the second annular groove 002 b.

Because first inner circle and second inner circle all need be along with hollow shaft 102 synchronous revolution, consequently for the inseparabler of connecting, need its and hollow shaft 102 interference fit, can produce the heat in the relative motion process, casing 002 can expand with the bearing when being heated, in order to reserve the expansion space, consequently first outer lane and first annular groove 002a clearance fit, second outer lane and second annular groove 002b clearance fit.

In order to ensure the uniform sound and the service life of the worm wheel 1 in the operation process of the linear actuator, the worm wheel 1 and the motor shaft 001a must ensure that the fixed center distance is engaged and the engagement precision between the worm wheel 1 and the motor shaft 001a cannot be affected by other parts, in this embodiment, the worm wheel 1 is fixed in the shell 002 through the first bearing 6 and the second bearing 7, the positioning precision of the worm wheel 1 only depends on the processing precision of the first annular groove 002a and the second annular groove 002b which are used as bearing positions for accommodating the first bearing 6 and the second bearing 7, so that the bearing position precision in the shell 002 is ensured when a mold is manufactured, the positioning precision of the worm wheel 1 can be well controlled in actual batch production, the control is easy, and the periodic abnormal sound and the damage of the worm wheel 1 caused by poor engagement of the worm wheel 1 and the motor shaft 001a are avoided.

As shown in fig. 2, a gasket 10 is arranged in front of the hollow shaft 102, a buffer ring 9 is arranged behind the hollow shaft 102, the buffer ring 9, the worm wheel 1, the gasket 10 and the nut 5 are sequentially sleeved on the screw rod 2 from back to front, and the shell 002 comprises an upper shell and a lower shell.

As shown in fig. 2 and 4, in order to axially limit the first bearing 6 and the second bearing 7, a first annular step 102a is disposed at the front end of the hollow shaft 102, the first bearing 6 is sleeved on the first annular step 102a, a second annular step 102b is disposed at the rear end of the hollow shaft 102, a third annular step 901 is disposed on the buffer ring 9, a third annular groove 11 is formed by the second annular step 102b and the third annular step 901, and the second bearing 7 is sleeved in the third annular groove 11.

The linear actuator of the present embodiment transmits the axial force as follows: push rod 4 → nut 5 → screw rod 2 → washer 10 → first bearing 6 → worm wheel 1 → second bearing 7 → housing 002.

The above description is only for the embodiments of the present invention, but the scope of the present invention is not limited thereto, and those skilled in the art should understand that the present invention includes but is not limited to the description in the above embodiments and the accompanying drawings. Any modification which does not depart from the functional and structural principles of the invention is intended to be included within the scope of the claims.

Claims

1. The utility model provides a linear actuator, includes driving motor and transmission assembly, driving motor includes the motor shaft, the transmission assembly includes worm wheel and lead screw, the worm wheel with the motor shaft meshing transmission, its characterized in that, the worm wheel cover is established on the lead screw and spacing with lead screw circumference, the worm wheel is equipped with the clearance with spacing department of lead screw circumference to offset the axiality deviation of worm wheel and lead screw.

2. The linear actuator of claim 1, wherein the worm gear is flat-fitting with the lead screw.

3. The linear actuator of claim 2, wherein the lead screw has a flat portion, the worm gear has a flat hole for fitting the flat portion, and the flat portion is in clearance fit with the flat hole.

4. The linear actuator of claim 3, wherein the flat comprises a double flat and the flat hole comprises a double flat hole.

5. The linear actuator of claim 1, further comprising a housing and a bearing through which the worm gear is positioned in the housing at both ends.

6. The linear actuator of claim 5, wherein the worm gear includes an annular tooth surface in meshing transmission with the motor shaft and a hollow shaft connected to the annular tooth surface, the hollow shaft is sleeved on the screw rod and axially limited to the screw rod, and the bearings include a first bearing and a second bearing respectively sleeved on the hollow shaft on two sides of the annular tooth surface.

7. A linear actuator as claimed in claim 6, wherein the housing is provided with a first annular recess to accommodate the first bearing and a second annular recess to accommodate the second bearing.

8. The linear actuator of claim 7, wherein the first and second bearings each comprise a deep groove ball bearing, the first bearing comprising a first outer race in interference fit with the hollow shaft and a first inner race in clearance fit with the first annular groove, the second bearing comprising a second outer race in interference fit with the hollow shaft and a second inner race in clearance fit with the second annular groove.

9. The linear actuator of claim 7, wherein the transmission assembly further includes a guide sleeve fixed to the housing, a push rod sleeved in the guide sleeve, and a nut sleeved on the lead screw, the nut is fixedly connected to the push rod, a spacer is disposed in front of the hollow shaft, a buffer ring is disposed in rear of the hollow shaft, and the buffer ring, the worm wheel, the spacer, and the nut are sequentially sleeved on the lead screw from rear to front.

10. The linear actuator of claim 9, wherein the front end of the hollow shaft is provided with a first annular step, the first bearing being seated on the first annular step, the rear end of the hollow shaft is provided with a second annular step, the bumper ring is provided with a third annular step, the second and third annular steps form a third annular groove, and the second bearing is seated in the third annular groove.