Actuator transmission mechanism and actuator

Abstract

The invention discloses an actuator transmission mechanism and an actuator. The actuator transmission mechanism comprises a lead screw; the lead screw nut is arranged on the lead screw in a matched mode and is in transmission connection with the lead screw. The locking ring is arranged on the lead screw nut in a sleeving mode and connected with the lead screw nut, one end of the locking ring is connected with the piston rod, and when the lead screw drives the lead screw nut to move, the piston rod is driven by the locking ring to stretch out or retract in the axial direction of the lead screw; a force bearing part is arranged on the lead screw nut, and when the lock ring is subjected to reverse acting force applied by the piston rod, the force can be transmitted to the force bearing part of the lead screw nut. By improving the structure of the transmission mechanism, the damage to the lead screw nut caused by the reverse acting force generated on the lead screw nut due to stalling when the actuator moves to the extension limit position can be avoided under the condition that the push-pull driving on the piston rod is met, and the transmission mechanism is simple in structure and has good reliability.

Description

Technical Field

[0001] The present invention belongs to the technical field of actuators, and in particular relates to an actuator transmission mechanism and an actuator. Background Art

[0002] The mechanical transmission part of the electric screw actuator (EMA) is usually composed of an AC servo motor, a gear set, a ball screw pair, etc. The motor is used as the power source to convert electrical energy into mechanical energy, and the torque is transmitted to the ball screw pair through the gear set. The rotation of the screw drives the linear motion of the screw nut to complete the extension and retraction action of the actuator piston assembly.

[0003] In the motion control of existing actuators, when the piston rod moves to the limit position, the position sensor will be triggered, and the position sensor will send a signal to the control system that the piston rod has moved to the limit position. After receiving the control signal, the control system will control the motor to stop running to achieve automatic control of the actuator. However, due to the time lag problem of the control system, after the piston rod moves to the limit position, the motor will continue to drive the transmission mechanism to move, resulting in a rapid increase in the stall torque at the end of the actuator, exerting an axial reaction force on the transmission mechanism, which is easy to cause damage to the transmission mechanism. Summary of the invention

[0004] The object of the present invention is to provide an actuator transmission mechanism and an actuator to solve the problem that the actuator transmission mechanism is easily damaged when subjected to a reaction force in the axial direction.

[0005] The present invention is achieved through the following technical solutions:

[0006] Actuator transmission mechanism, comprising:

[0007] Lead screw;

[0008] A lead screw nut, which is arranged on the lead screw and is in transmission connection with the lead screw;

[0009] A locking ring is sleeved on the lead screw nut and connected to the lead screw nut. One end of the locking ring is connected to the piston rod. When the lead screw drives the lead screw nut to move, the piston rod is driven to extend or retract along the axial direction of the lead screw through the locking ring.

[0010] The screw nut is provided with a load-bearing part, and when the locking ring is subjected to a reverse force exerted by the piston rod, the force can be transmitted to the load-bearing part of the screw nut.

[0011] In some embodiments, the locking ring is connected to the screw nut at the load-bearing part of the screw nut.

[0012] In some embodiments, a first groove is provided on the outer circumference of the screw nut, a second groove is provided on the inner circumference of the locking ring, and blocks are provided in the first groove and the second groove, and the locking ring and the screw nut are connected via the blocks.

[0013] In some embodiments, the first groove and the second groove are annular grooves, and there are a plurality of blocks, which are circumferentially arranged in the first groove and the second groove.

[0014] On the other hand, the present invention also provides an actuator, comprising:

[0015] Transmission mechanism;

[0016] And a piston rod, the piston rod is sleeved on the lead screw, and the locking ring is connected to the piston rod at one end.

[0017] In some embodiments, one end of the locking ring is connected to a retaining frame, and the retaining frame is disposed in a cavity at one end of the piston rod. A third groove is disposed in the cavity of the piston rod, and a flange of the retaining frame is cooperatively disposed in the third groove.

[0018] In some embodiments, an axial dimension of the third groove is greater than an axial dimension of the flange of the retainer, so that the flange of the retainer can move in the third groove along the axial direction.

[0019] In some embodiments, a flange protruding radially inward is provided at one end of the locking ring, and a locking block is provided at one end of the retaining frame. A fourth groove that can just accommodate the flange is formed between the locking block and the flange of the retaining frame, and the locking ring is connected to the retaining frame through the cooperation between the flange and the fourth groove.

[0020] In some embodiments, the locking block is disposed in a locking ring, a spacer is disposed between the locking block and the lead screw nut, and a clearance fit is formed between an end face of one end of the spacer and an end face of the lead screw nut.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] The present invention improves the structure of the transmission mechanism so that it can avoid damage to the lead screw nut caused by the reverse force generated on the lead screw nut due to stalling when the actuator moves to the extension limit position while satisfying the push-pull drive of the piston rod. The structure is simple and has good reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 A schematic diagram of an actuator structure.

[0025] Figure 2 Schematic diagram of the transmission mechanism and actuator structure in an embodiment of the present invention.

[0026] in:

[0027] 1. gear, 2. lead screw, 3. lead screw nut, 4. locking ring, 41. flange, 5. piston rod, 51. third groove, 6. retaining frame, 7. locking sleeve, 8. locking block, 9. clamping block, 10. spacer block. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0029] During the actuator operation, refer to Figure 1 To achieve the extension and retraction of the actuator, the action process between the lead screw nut and the piston rod is as follows:

[0030] The motor drives the lead screw 2 to rotate, and the lead screw 2 rotates and drives the lead screw nut 3 to move along the lead screw axial direction toward the piston rod extension direction, pushing the piston rod 5 to extend outward; when the lead screw nut 3 moves in the opposite direction, it pulls the piston rod inward to retract.

[0031] When the piston rod 5 is extended, the end surface of the lead screw nut 3 contacts the piston rod 5, and the output force is transmitted through the surface contact between the lead screw nut and the piston rod, thereby pushing the piston rod to move.

[0032] When the piston rod 5 is retracted, the claw-shaped groove structure at the cantilever end of the lead screw nut 3 pulls the piston rod to retract the piston rod.

[0033] Use Figure 1The actuator of the structure shown in the figure will trigger the lower limit position sensor after driving the piston rod 5 to extend into position, and output an extended position signal to the control system, and the control system controls the motor to stop moving; but due to the time lag of the control system, during the time lag, the motor will continue to drive the piston rod 5 to move in the extending direction, causing the stall torque at the end of the actuator to increase rapidly. At this time, the piston rod generates a reverse force on the cantilever end of the screw nut 3 in the axial direction, and this force acts on the claw groove structure of the cantilever end of the screw nut, which can easily cause damage to the screw nut 3.

[0034] In view of the problem that the lead screw nut is easily damaged in the above structure, in some embodiments of the present invention, Figure 1 The actuator transmission mechanism shown in is improved, referring to Figure 2 , the actuator transmission mechanism includes:

[0035] Screw 2; Screw 2 adopts ball screw;

[0036] The lead screw nut 3 is arranged on the lead screw 2 and is in transmission connection with the lead screw;

[0037] The locking ring 4 is sleeved on the lead screw nut and connected to the lead screw nut. The locking ring 4 is connected to the piston rod 5 at one end. When the lead screw drives the lead screw nut to move, the piston rod is driven to extend or retract along the axial direction of the lead screw through the locking ring.

[0038] A load-bearing part is provided on the screw nut 3, and the structural strength of the load-bearing part is greater than that of other parts, so that when subjected to the same magnitude of force, the load-bearing part is less likely to be damaged, for example, the load-bearing part has a greater wall thickness.

[0039] When the locking ring is subjected to the reaction force exerted by the piston rod, it can transmit the force to the load-bearing part of the lead screw nut.

[0040] By setting a locking ring as a force transmission component between the screw nut and the piston rod in the transmission mechanism, the reaction force generated during stalling can be transmitted to the load-bearing part of the screw nut, which effectively solves the problem of damage to the screw nut caused by the stalling force.

[0041] In some embodiments, the locking ring 4 is connected to the screw nut 3 at the load-bearing part of the screw nut, so that the force can directly act on the load-bearing part of the screw nut.

[0042] In some embodiments, Figure 1 As shown, at the block setting position, a first groove is provided on the outer circumference of the screw nut 3, a second groove is provided on the inner circumference of the locking ring 4, and a block 9 is provided in the first groove and the second groove. The locking ring 4 and the screw nut 3 are connected via the block 9.

[0043] A part of the clamping block 9 is arranged in the first groove, and the other part is arranged in the second groove. The connection between the locking ring and the screw nut is realized by the matching connection between the clamping block and the first groove and the second groove. The clamping block has a good bearing capacity under the reaction force generated by the stalling, which can well avoid failure at the connection position and ensure the reliability of the connection structure.

[0044] Here, both the first groove and the second groove can be configured as annular grooves.

[0045] The clamping block 9 is divided into a plurality of parts and is evenly arranged in the circumferential direction. The clamping block is divided into a plurality of independent structures, which can facilitate the installation of the clamping block in the first groove and the second groove.

[0046] On the other hand, based on the improvement of the actuator transmission mechanism, some embodiments of the present invention further provide an actuator, which adopts the transmission mechanism in the above embodiments; accordingly, the actuator can well avoid damage to the screw nut caused by stalling during operation.

[0047] like Figure 2 In some embodiments, the actuator includes a piston rod 5, which is sleeved on the lead screw 2, and a locking ring 4 is connected to the piston rod 5 at one end.

[0048] In some embodiments, a retainer 6 is connected to one end of the locking ring 4, and the retainer 6 is arranged in a cavity at one end of the piston rod 5. A third groove 51 is arranged in the cavity of the piston rod, and a flange of the retainer 6 is arranged in the third groove 51. In this way, when the transmission mechanism drives the screw nut to move, the connection structure between the retainer and the piston rod can push or pull the piston rod to move in the axial direction.

[0049] In some embodiments, the axial dimension of the third groove 51 is greater than the axial dimension of the flange of the retainer 6, so that the flange of the retainer can move in the axial direction in the third groove. In this way, when the driving piston rod is driven between extension and retraction, a certain buffer space is provided for the switching action.

[0050] In some embodiments, a flange 41 protruding radially inward is provided at one end of the locking ring 4, and a structure similar to a claw-shaped groove is formed at this end of the locking ring; a locking block 8 is provided at one end of the retaining frame, and a fourth groove that can just accommodate the flange is formed between the locking block 8 and the flange of the retaining frame 6, and the locking ring is connected to the retaining frame through the cooperation between the flange and the fourth groove.

[0051] The connection between the locking ring and the retaining frame is facilitated by the cooperation between the claw-shaped groove structure at the end of the locking ring and the locking block.

[0052] In some embodiments, the locking block 8 is arranged in the locking ring 4, and a spacer block 10 is arranged between the locking block 8 and the screw nut 3. The end face of one end of the spacer block 10 is clearance-matched with the end face of the screw nut 3. The matching structure between the locking ring and the screw nut is utilized to facilitate the connection between the locking ring and the retaining frame through the locking block.

[0053] A locking sleeve 7 is arranged in the cavity of the piston rod 5 . The locking sleeve 7 is sleeved on the lead screw 2 and connected to the retaining frame 6 at one end.

[0054] A gear 1 is arranged at one end of the lead screw 2 for transmission between the motor and the lead screw.

[0055] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. used to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship commonly placed when the product of the invention is used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 invention.

[0056] In addition, if the terms "horizontal" or "vertical" appear in the description of the present invention, it does not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0057] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 the present invention can be understood in combination with specific circumstances.

[0058] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. Actuator transmission mechanism, characterized in that: include: Lead screw; A lead screw nut, which is arranged on the lead screw and is in transmission connection with the lead screw; A locking ring is sleeved on the lead screw nut and connected to the lead screw nut. One end of the locking ring is connected to the piston rod. When the lead screw drives the lead screw nut to move, the piston rod is driven to extend or retract along the axial direction of the lead screw through the locking ring. The screw nut is provided with a load-bearing part, and when the locking ring is subjected to a reverse force exerted by the piston rod, the force can be transmitted to the load-bearing part of the screw nut.

2. The actuator transmission mechanism according to claim 1, characterized in that: The locking ring is connected to the lead screw nut at the load-bearing part of the lead screw nut.

3. The actuator transmission mechanism according to claim 1 or 2, characterized in that: A first groove is arranged on the outer circumference of the lead screw nut, a second groove is arranged on the inner circumference of the lock ring, and clamping blocks are arranged in the first groove and the second groove, and the lock ring and the lead screw nut are connected via the clamping blocks.

4. The actuator transmission mechanism according to claim 1 or 2, characterized in that: The first groove and the second groove are annular grooves, and there are a plurality of clamping blocks, which are circumferentially arranged in the first groove and the second groove.

5. An actuator, characterized in that: include: The transmission mechanism according to any one of claims 1 to 4; And a piston rod, the piston rod is sleeved on the lead screw, and the locking ring is connected to the piston rod at one end.

6. The actuator according to claim 5, characterized in that: One end of the lock ring is connected to a retaining frame, and the retaining frame is arranged in a cavity at one end of the piston rod. A third groove is arranged in the cavity of the piston rod, and a flange of the retaining frame is matched and arranged in the third groove.

7. The actuator according to claim 6, characterized in that: The axial dimension of the third groove is greater than the axial dimension of the flange of the retaining frame, so that the flange of the retaining frame can move in the third groove along the axial direction.

8. The actuator according to claim 6, characterized in that: A flange protruding radially inward is provided at one end of the locking ring, and a locking block is provided at one end of the retaining frame. A fourth groove that can just accommodate the flange is formed between the locking block and the flange of the retaining frame, and the locking ring is connected to the retaining frame through the cooperation between the flange and the fourth groove.

9. The actuator according to claim 8, characterized in that The locking block is arranged in the locking ring, a cushion block is arranged between the locking block and the lead screw nut, and a clearance fit is formed between an end face of one end of the cushion block and an end face of the lead screw nut.

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