Reverse transmission mechanical locking device and electric cylinder

Abstract

The invention discloses a reverse transmission mechanical locking device and an electric cylinder, and the reverse transmission mechanical locking device comprises an input shaft which is connected to the power output end of a motor; the first end of the convex sleeve is connected with the input shaft, and the second end of the convex sleeve is provided with a convex structure; the taper sleeve is connected to the lead screw shaft through a key, the small end of the taper sleeve is provided with a groove matched with the protruding structure, and the taper sleeve is provided with an outer conical surface; the sleeve is relatively and fixedly connected with a shell of the electric cylinder, is positioned outside the taper sleeve and is provided with an inner conical surface matched with the outer conical surface of the taper sleeve; one end of the compression elastic piece is pressed on the step end face of the lead screw shaft, and the other end of the compression elastic piece abuts against the large-head end face of the taper sleeve; and under the thrust action of the compression elastic piece, the taper sleeve axially moves towards the convex sleeve, so that the outer conical surface of the taper sleeve is in contact with the inner conical surface of the sleeve to generate locking friction torque.

Description

Technical Field

[0001] The invention belongs to the technical field of electric cylinders and relates to a reverse transmission mechanical locking device and an electric cylinder. Background Art

[0002] Since its emergence, electric cylinder technology has gone through several stages of discovery. Initially, it was a gear rack and nut-screw structure, followed by an electro-hydraulic push rod and ball screw electric cylinder. In particular, the ball screw electric cylinder replaces sliding friction with the rolling friction of the ball, which greatly improves transmission efficiency and reduces wear.

[0003] Due to the low friction characteristics of ball screws, while improving transmission efficiency, it also brings the defect of not being able to self-lock. A common solution is to achieve it by integrating an anti-reverse transmission mechanism (such as a mechanical self-locking device, a normally closed electromagnetic clutch). It can prevent the reverse transmission of the ball screw during the pause phase of the linear motion or when the machine is shut down.

[0004] There are currently two technical solutions for ball screw electric cylinders, one is an electromagnetic reverse transmission locking device and the other is a mechanical reverse transmission locking device. However, the existing solutions have the following disadvantages.

[0005] The disadvantages of electromagnetic reverse transmission locking device technology are: 1. The reliability of electromagnetic clutch is lower than that of mechanical clutch, and its use is limited in important working occasions. 2. The cost of electromagnetic clutch is higher than that of mechanical clutch.

[0006] The disadvantages of the expansion coil torsion spring self-locking device technology are: 1. The mechanism is complex, and the disadvantages of complexity are complex processing and assembly, and high cost. 2. Poor bearing capacity. The roller and torsion spring are bent at points and lines because the force-bearing parts cannot be extended to a large area. There are disadvantages such as unsatisfactory torque transmission capacity and low reliability. Summary of the invention

[0007] Purpose: In view of at least one of the above technical problems, the present invention provides a reverse transmission mechanical locking device and an electric cylinder, which can prevent the reverse transmission caused by the lead screw dragging the motor when the motor is not working.

[0008] Technical solution: To solve the above technical problems, the technical solution adopted by the present invention is: In a first aspect, a reverse transmission mechanical locking device is provided, comprising: An input shaft connected to the power output end of the motor; A convex sleeve, wherein a first end of the convex sleeve is connected to the input shaft, and a convex structure is provided at a second end of the convex sleeve; A cone sleeve is connected to the screw shaft through a key, the small end of the cone sleeve is provided with a groove matching the protruding structure, and the cone sleeve is provided with an outer cone surface; A sleeve is relatively fixedly connected to the housing of the electric cylinder and is located outside the cone sleeve. It is provided with an inner cone surface that matches the outer cone surface of the cone sleeve. The minimum inner hole diameter of the sleeve is smaller than the maximum outer diameter of the cone sleeve, and the maximum inner hole diameter of the sleeve is larger than the maximum outer diameter of the cone sleeve. A compression elastic member has one end pressed on the step end face of the screw shaft and the other end abutted against the large end face of the tapered sleeve; and under the thrust of the compression elastic member, the tapered sleeve moves axially toward the convex sleeve so that the outer cone surface of the tapered sleeve contacts the inner cone surface of the sleeve to generate a locking friction torque.

[0009] In some embodiments, the reverse transmission mechanical locking device, in the positive transmission state, the convex sleeve connected to the input shaft rotates to transmit torque, the convex structure of the convex sleeve is pressed into the groove of the tapered sleeve, and the rotation of the convex sleeve squeezes the tapered sleeve through the convex structure, causing the tapered sleeve to separate from the sleeve. At this time, the locking friction torque provided by the sleeve disappears, and the torque can be transmitted to the screw shaft through the tapered sleeve and the key.

[0010] In some embodiments, in the reverse transmission mechanical locking device, the input shaft does not provide torque in the reverse transmission state, and the convex sleeve passively follows the tapered sleeve and cannot provide thrust to push the tapered sleeve out of the sleeve. Therefore, the locking friction torque provided by the sleeve always exists, and the tapered sleeve and the sleeve are always in a locked state, resulting in the inability to reversely transmit the torque and rotation of the screw shaft, thereby realizing reverse transmission mechanical locking.

[0011] In some embodiments, the compression elastic member is a compression spring.

[0012] In some embodiments, the key connection is a flat key connection, a semicircular key connection, a wedge key connection or a tangential key connection.

[0013] In some embodiments, the protrusion structure is a V-shaped cone protrusion structure.

[0014] In some embodiments, the groove is a V-shaped groove that matches the V-shaped cone protrusion structure.

[0015] In some embodiments, the minimum inner diameter of the sleeve is greater than the minimum outer diameter of the cone sleeve.

[0016] In some embodiments, the convex sleeve and the conical sleeve are arranged coaxially.

[0017] In a second aspect, an electric cylinder is provided, comprising the reverse transmission mechanical locking device.

[0018] Beneficial effects: The reverse transmission mechanical locking device and electric cylinder provided by the present invention have the following advantages: the reverse transmission locking function is realized by fewer parts such as a convex sleeve with a convex structure and a conical sleeve with a groove; the torque is transmitted and cut off by the conical surface, and the torque is transmitted by a large surface contact on the basis of simplification to effectively improve the torque bearing capacity. Fewer parts and a large surface contact torque transmission working mode mean high reliability; because the torque transmission is a large surface contact working mode, the torque transmission capacity is significantly improved; it is easy to process and assemble, and is very effective in realizing the function; it can be applied to ball screws and roller screws, but is not limited to screw-type transmission devices, and is suitable for electric cylinders. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a cross-sectional schematic diagram of a reverse transmission mechanical locking device according to an embodiment of the present invention; Figure 2 is a schematic structural diagram of a reverse transmission mechanical locking device according to an embodiment of the present invention; In the figure: input shaft 1, convex sleeve 2, convex structure 21, tapered sleeve 3, groove 31, outer cone surface 32, key 4, sleeve 5, inner cone surface 51, compression elastic member 6, screw shaft 7. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0022] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "multiple" means two or more.

[0023] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0024] Example 1: Figure 1 , Figure 2 As shown, a reverse transmission mechanical locking device comprises: Input shaft 1, connected to the power output end of the motor; A convex sleeve 2, wherein a first end of the convex sleeve 2 is connected to the input shaft 1, and a convex structure 21 is provided at a second end of the convex sleeve; The cone sleeve 3 is connected to the screw shaft 7 through a key 4. The small end of the cone sleeve 3 is provided with a groove 31 that matches the protruding structure 21. The cone sleeve 3 is provided with an outer cone surface 32. The sleeve 5 is relatively fixedly connected to the housing of the electric cylinder and is located outside the cone sleeve 3. It is provided with an inner cone surface 51 that matches the outer cone surface of the cone sleeve 3. The minimum inner hole diameter of the sleeve 5 is smaller than the maximum outer diameter of the cone sleeve 3, and the maximum inner hole diameter of the sleeve 5 is larger than the maximum outer diameter of the cone sleeve 3. One end of the compression elastic member 6 is pressed on the step end face of the screw shaft 7, and the other end is abutted against the large end face of the tapered sleeve 3; and under the thrust of the compression elastic member 6, the tapered sleeve 3 moves axially toward the convex sleeve 2, so that the outer conical surface of the tapered sleeve 3 contacts the inner conical surface of the sleeve 5 to generate a locking friction torque.

[0025] The reverse transmission mechanical locking device of the embodiment of the present application, in the positive transmission state, the convex sleeve 2 connected to the input shaft 1 rotates to transmit torque, the convex structure 21 of the convex sleeve 2 is pressed into the groove 31 of the tapered sleeve 3, and the rotation of the convex sleeve 2 squeezes the tapered sleeve 3 through the convex structure 21, causing the tapered sleeve 3 to separate from the sleeve 5. At this time, the locking friction torque provided by the sleeve 5 disappears, and the torque can be transmitted to the screw shaft 7 through the tapered sleeve 3 and the key 4.

[0026] In the reverse transmission mechanical locking device of the embodiment of the present application, in the reverse transmission state, the input shaft 1 does not provide torque, the convex sleeve 2 passively follows the tapered sleeve 3 and cannot provide thrust to push the tapered sleeve 3 out of the sleeve 5. Therefore, the locking friction torque provided by the sleeve 5 always exists, and the tapered sleeve 3 and the sleeve 5 are always in a locked state, resulting in the inability to reversely transmit the torque and rotation of the screw shaft 7, thereby realizing reverse transmission mechanical locking.

[0027] In some embodiments, the compression elastic member 6 may be a compression spring.

[0028] In some embodiments, the key connection adopts a flat key connection, a semicircular key connection, a wedge key connection or a tangential key connection. In the embodiment of the present application, the key 4 adopts a flat key. In the present application, the circumferential fixation of the cone sleeve 3 on the screw shaft 7 is achieved by the key connection, and the cone sleeve 3 can only move with a certain axial displacement.

[0029] In some embodiments, the protrusion structure is a V-shaped cone protrusion structure, and correspondingly, the groove is a V-shaped groove matching the V-shaped cone protrusion structure.

[0030] In the reverse transmission mechanical locking device of the embodiment of the present application, the minimum inner diameter of the sleeve 5 is larger than the minimum outer diameter of the cone sleeve 3, so that the small end of the cone sleeve 3 can extend out of the sleeve 5 and be combined with the convex sleeve 2.

[0031] In some embodiments, the convex sleeve 2 is coaxially arranged with the tapered sleeve 3. More preferably, the convex sleeve 2, the tapered sleeve 3 and the screw shaft 7 are coaxially arranged.

[0032] In some embodiments, Figure 1 , Figure 2 As shown, a reverse transmission mechanical locking device includes an input shaft 1, a convex sleeve 2, a tapered sleeve 3, a flat key, a sleeve 5, a compression spring, and a screw shaft 7; The input shaft 1 is connected to the convex sleeve 2, and the tapered sleeve 3 is connected to the screw shaft 7 through a flat key. The tapered sleeve 3 is provided with an outer tapered surface. The sleeve 5 is relatively fixedly connected to the housing of the electric cylinder and is located outside the tapered sleeve 3. The sleeve 5 is provided with an inner tapered surface matching the outer tapered surface of the tapered sleeve 3. The maximum outer diameter of the tapered sleeve 3 is greater than the minimum inner aperture of the sleeve 5, and the maximum inner aperture of the sleeve 5 is greater than the maximum outer diameter of the tapered sleeve 3, and the minimum inner aperture of the sleeve 5 is greater than the minimum outer diameter of the tapered sleeve 3; one end of the compression spring is pressed on the step end face of the screw shaft 7, and the other end of the compression spring is abutted against the first end face of the tapered sleeve 3. The second end face of the tapered sleeve 3 is provided with a V-shaped groove, and the end of the convex sleeve 2 close to the tapered sleeve 3 is provided with a V-shaped cone protrusion structure matching the V-shaped groove.

[0033] This embodiment can realize the reverse transmission locking function. The torque input by the input shaft 1 can be transmitted to the screw shaft 7 through the convex sleeve 2 and the tapered sleeve 3, but the reverse torque cannot be transmitted. The specific implementation method is as follows: In the positive transmission state, under the action of the compression spring, the tapered sleeve 3 and the sleeve 5 are in a locked state due to the friction between the outer tapered surface and the inner tapered surface; the convex sleeve 2 connected to the input shaft 1 rotates to transmit torque, and the V-shaped cone protrusion structure of the convex sleeve 2 is pressed into the V-shaped groove of the tapered sleeve 3. The rotation of the convex sleeve 2 squeezes the tapered sleeve 3 through the V-shaped cone protrusion structure, causing the tapered sleeve 3 to separate from the sleeve 5. At this time, the locking friction force provided by the sleeve 5 disappears, and the torque can be transmitted to the screw shaft 7 through the tapered sleeve 3 and the flat key.

[0034] In the reverse transmission state, under the action of the compression spring, the cone sleeve 3 and the sleeve 5 are in a locked state due to the friction between the outer cone surface and the inner cone surface; the input shaft 1 does not provide torque, and the convex sleeve 2 passively follows the cone sleeve 3 and cannot provide thrust to push the cone sleeve 3 out of the sleeve 5. Therefore, the locking friction force provided by the sleeve 5 always exists, resulting in the inability to reversely transmit torque and rotation, thereby realizing reverse transmission mechanical locking.

[0035] The reverse transmission mechanical locking device provided by the present application realizes the reverse transmission locking function through fewer parts such as a convex sleeve with a protruding structure and a conical sleeve with a groove; the torque is transmitted and cut off through the conical surface, and fewer parts and a large-surface contact torque transmission working mode mean high reliability; because the torque transmission is a large-surface contact working mode, the torque transmission capacity is significantly improved; it is easy to process and assemble, and is very effective in realizing the function; it can be applied to ball screws and roller screws, but is not limited to screw-type transmission devices, and is suitable for electric cylinders.

[0036] Embodiment 2: An electric cylinder, comprising the reverse transmission mechanical locking device described in Embodiment 1.

[0037] In some embodiments, the electric cylinder further includes a motor, and a power output end of the motor is drivingly connected to the input shaft 1 to provide torque for the input shaft.

[0038] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A reverse transmission mechanical locking device, characterized in that: include: An input shaft connected to the power output end of the motor; A convex sleeve, wherein a first end of the convex sleeve is connected to the input shaft, and a convex structure is provided at a second end of the convex sleeve; A cone sleeve is connected to the screw shaft through a key, the small end of the cone sleeve is provided with a groove matching the protruding structure, and the cone sleeve is provided with an outer cone surface; A sleeve is relatively fixedly connected to the housing of the electric cylinder and is located outside the cone sleeve. It is provided with an inner cone surface that matches the outer cone surface of the cone sleeve. The minimum inner hole diameter of the sleeve is smaller than the maximum outer diameter of the cone sleeve, and the maximum inner hole diameter of the sleeve is larger than the maximum outer diameter of the cone sleeve. A compression elastic member has one end pressed on the step end face of the screw shaft and the other end abutted against the large end face of the tapered sleeve; and under the thrust of the compression elastic member, the tapered sleeve moves axially toward the convex sleeve so that the outer cone surface of the tapered sleeve contacts the inner cone surface of the sleeve to generate a locking friction torque.

2. The reverse transmission mechanical locking device according to claim 1, characterized in that: In the positive transmission state, the convex sleeve connected to the input shaft rotates to transmit torque, and the convex structure of the convex sleeve is pressed into the groove of the taper sleeve. The rotation of the convex sleeve squeezes the taper sleeve through the convex structure, causing the taper sleeve to separate from the sleeve. At this time, the locking friction torque provided by the sleeve disappears, and the torque can be transmitted to the screw shaft through the taper sleeve and the key.

3. The reverse transmission mechanical locking device according to claim 1, characterized in that: In the reverse transmission state, the input shaft does not provide torque, and the convex sleeve passively follows the tapered sleeve and cannot provide thrust to push the tapered sleeve out of the sleeve. Therefore, the locking friction torque provided by the sleeve always exists, and the tapered sleeve and the sleeve are always in a locked state, resulting in the inability to reversely transmit the torque and rotation of the screw shaft, thereby realizing reverse transmission mechanical locking.

4. The reverse transmission mechanical locking device according to claim 1, characterized in that: The compression elastic member is a compression spring.

5. The reverse transmission mechanical locking device according to claim 1, characterized in that: The key connection adopts a flat key connection, a semicircular key connection, a wedge key connection or a tangential key connection.

6. The reverse transmission mechanical locking device according to claim 1, characterized in that: The protrusion structure is a V-shaped cone protrusion structure.

7. The reverse transmission mechanical locking device according to claim 6, characterized in that: The groove is a V-shaped groove matched with the V-shaped cone protrusion structure.

8. The reverse transmission mechanical locking device according to claim 1, characterized in that: The minimum inner diameter of the sleeve is greater than the minimum outer diameter of the cone sleeve.

9. The reverse transmission mechanical locking device according to any one of claims 1 to 8, characterized in that: The convex sleeve and the conical sleeve are coaxially arranged.

10. An electric cylinder, characterized in that: It comprises the reverse transmission mechanical locking device as described in any one of claims 1 to 9.

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