CN100404913C

CN100404913C - Self position limit linear actuator

Info

Publication number: CN100404913C
Application number: CNB200510033221XA
Authority: CN
Inventors: 徐众
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-02-18
Filing date: 2005-02-18
Publication date: 2008-07-23
Anticipated expiration: 2025-02-18
Also published as: CN1821620A

Abstract

The present invention relates to an electric linear driving device, particularly to a self position limit linear actuator which can replace hydraulic pressure and pneumatic power to drive cylinders in machinery; the actuator which is provided with a self limiter makes linear motion by a screw rod or a rolling ball screw, wherein the actuator is provided with a self position limiting screw mechanism. A forward wheel and a backward wheel are processed on the surface of a locating shaft sleeve; a rolling bearing or a sliding sleeve is installed between a screw sleeve and a locating sleeve. When a slide seat is driven to a limit position by the screw rod, a locating lock sheet is driven to enhance by a locating wheel which is positioned at the end of the screw rod, and free rotation is generated between the screw sleeve and the locating shaft sleeve, so the screw rod and a driving system are protected from overloading. In the same way, when the present invention rotates in a reverse direction and a fixed slide block moves to the other end, the free rotation is also generated and the function of two-way limit protection can be obtained. The driving can be widely used for replacing the structure of the traditional hydraulic and the pneumatic driving cylinders, such as medical instruments, automatic lathes, automatic control servo driving systems, etc. The present invention has the characteristics of energy saving, favorable stiffness, high precision, etc.

Description

Self position limit linear actuator

Technical field

A kind of electric linear actuator replaces hydraulic pressure and pneumatic drive cylinder body in machinery, with the band of motor driving screw rod or the ball screw moving linearly actuator from limit stoper.Can be used on for example medical apparatus, automatic lathe is controlled on the movement meanss such as servo drive system automatically.

Background technique

Compare traditional hydraulic pressure or pneumatic linear actuator driving mode; this kind driving mode is a motorized motions; need not oil hydraulic pump or air compressor; need not to dispose hydraulic station or air compression station; save the energy significantly, the inner band of actuator mechanical limiting location device, good reliability; do not produce overload and impact, can effectively protect the two-way smooth running of screw rod or ball screw and drive system.

Summary of the invention

Existing linear actuator is used limit switch usually, electromagnetic sensor, and devices such as overcurrent protection carry out end position limiting to actuator, and cost is higher, and screw rod can produce overload and distortion when spacing inefficacy, and motor also produces jam and excess current phenomenon.

This mechanical type position limit linear actuator produces idle running by elasticity location locking plate and positioning wheel control swivel nut and reaches limit effect, and simple in structure, cost is lower, does not produce overload in the running, can effectively protect the normal back and forth operation of its screw rod and motor.

Description of drawings

As shown in Figure 1, motor (21) output shaft (22) is equipped with worm screw (19), drives worm gear (20) rotation, and install at spiral shell wheel two ends Rolling bearing (16) is arranged, and bearing (16) and worm gear (20) are installed in screw rod (7) one ends. Be equipped with on the screw rod from position limiting slide block, by Positioning shaft sleeve (11), swivel nut (9), first elasticity location locking plate (23) and second elasticity that are installed in swivel nut (9) two ends are located locking plate (8), the rolling bearing (10) in the middle of swivel nut (9) and the positioning shaft sleeve (11) forms. When driving swivel nut (9), screw rod (7) moves to During the right side extreme position, drive second elasticity location locking plate (8) by second locating wheel (5) that is positioned at the screw rod end and lift, discharge this One-way wheel on the position positioning shaft sleeve (11) makes to produce idle running between swivel nut (9) and the positioning shaft sleeve (11), thus the protection spiral shell Bar (7) does not produce jam and overload with the drive system that links to each other. During reverse rotation, the upper left one-way wheel of positioning shaft sleeve (11) is subjected to One location locking plate (23) location, swivel nut (9) drives positioning shaft sleeve (11) and moves left, and second elasticity that is lifted simultaneously is fixed Position locking plate (8) resets and is pressed into the right one-way wheel. In like manner, when slide block movement arrived the left-hand end position, first elasticity location locking plate (23) was subjected to First locating wheel (14) acts on and lifting, and produces idle running between swivel nut (9) and the positioning shaft sleeve (11) and obtains two-way spacing guarantor Protective function. Guide rod (4) links to each other with positioning shaft sleeve (11), promotes ball and socket joint (1) motion of rod end.

Sliding sleeve (25) overcoat has sleeve pipe (3), and an end is connected the location by kink (2) with sliding sleeve (25), the other end by Cover plate (13) is positioned on the axle box (17).

Among Fig. 2, the part schematic diagram of sliding sleeve (25) and positioning shaft sleeve (11) has stop pin (12) on the positioning shaft sleeve (11), Embed in the chute in the sliding sleeve (25). Positioning shaft sleeve (11) inner circumferential surface both sides are forward and reverse one-way wheel structure.

Swivel nut (9) is located locking plate (8) respectively clockwise by first elasticity location locking plate (23) and second elasticity of both sides respectively, is rotated counterclockwise the location.

First elasticity location locking plate (23) and second elasticity location locking plate (8) are pressed on forward and reverse one-way wheel of the both sides on the location axle sleeve (11) by spring respectively.

Because the axial force that screw rod (7) rotation produces stops on first positioning wheel (14) and second positioning wheel (5) at screw rod two ends, location axle sleeve (11) is not subjected to the acting from the useless axial force of screw rod (7) when the end position, can avoid the distortion and the wearing and tearing of screw rod (7) and swivel nut (9).

Embodiment

Be used to replace oil hydraulic cylinder or cylinder, by the rotating speed and the rotating cycle of control motor (21), speed and the position of may command ball and socket joint (1) are used for straight line motion and accurate location, can be used for as lathe, and medical equipment are on the equipment such as building.

Claims

1. electric linear actuator, it is characterized in that: first positioning wheel (14) and second positioning wheel (5) that are positioned at screw rod (7) two ends, swivel nut (9) and location axle sleeve (11), and be positioned at bearing (10) between swivel nut (9) and location axle sleeve (11), do clockwise and be rotated counterclockwise the location respectively by first elasticity location locking plate (23) and second elasticity location locking plate (8) between swivel nut (9) and the location axle sleeve (11), do axially and radial location by bearing (10), guide pin bushing (4) is installed on the location axle sleeve (11), promote ball and socket joint (1) axial motion, screw rod (7) one termination worm gears (20) and worm screw (19), by motor (21) rotary driving, location axle sleeve (11) is positioned in the chute of sliding sleeve (25) by stop pin (12), axially reciprocatingly slide, the both sides circumferential surface of location axle sleeve (11) is processed as positive and negative one-way wheel structure, and the centre is the Bearing Installation position location.

2. electric linear actuator according to claim 1, it is characterized in that: swivel nut (9) is gone up first elasticity location locking plate (23) and second elasticity location locking plate of installing (8), it is characterized in that being pressed into respectively and be positioned to locate positive and negative one-way wheel one side in the surperficial left and right sides of axle sleeve (11), the location locking plate has independent spring to depress, also can be by under the spring pressure, one-sided elasticity location locking plate is at least more than a slice.

3. electric linear actuator according to claim 1, it is characterized in that: first positioning wheel (14) and second positioning wheel (5), be installed in screw rod (7) two ends, with right 2 described first elasticity location locking plate (23) and locking plate (8) actings in conjunction of second elasticity location, finish and lift and depress action, the location and the rotation of the one-way wheel on the control location axle sleeve (11).

4. electric linear actuator according to claim 1, it is characterized in that: bearing (10) is installed between swivel nut (9) and the location axle sleeve (11), and with stressed different, bearing (10) can be an above rolling bearing or sliding shaft sleeve according to rotational speed.

5. electric linear actuator according to claim 1, it is characterized in that: screw rod (7) is connected with limit stoper, can be regular screw threads, trapezoidal thread, or ball screw, roller screw mandrel.

6. electric linear actuator according to claim 1, it is characterized in that: screw rod (7) one ends drive and can be driven by worm gear (20) and worm screw (19), also can drive by the direct connecting screw rod of motor, or the driving of connection gear case.

7. electric linear actuator according to claim 1, it is characterized in that: sliding sleeve (25) surface Machining has chute, is positioned in the chute with stop pin (12) on the location axle sleeve (11), is in axial sliding in sliding sleeve (25).

8. electric linear actuator according to claim 1, it is characterized in that: circular sliding sleeve (25) can adopt square tubular, rectangular tube, oval pipe is as the design of the outer sliding sleeve of location axle sleeve of respective shapes.