Servo motor overload protection mechanical limiting mechanism

Abstract

The utility model discloses a kind of servo motor overload protection mechanical limiting mechanism, the utility model relates to overload protection technical field, including bottom plate, the upper end surface of bottom plate is provided with protection assembly and brake assembly, protection assembly includes servo motor, protection box, transmission shaft, connecting block, fixed plate, clamping block, moving disc, moving plate, limit frame and moving block, the side wall of servo motor is connected with the side of bottom plate, the utility model has the advantages that the initial position of moving plate can be adjusted by the threaded rod of protection box inner wall, the pre-tightening force of spring is changed, the greater pre-tightening force, the higher overload threshold that trigger clamping block is separated, otherwise is lower, to adapt to the protection demand under different load scene, after overload is removed, the elastic force of spring pushes moving plate, limit frame and moving disc reset, clamping block is reconnected with connecting block, device can restore normal work without manual reset, improve use convenience.

Description

Technical Field

[0001] This utility model relates to the field of overload protection technology, specifically to a mechanical limit mechanism for overload protection of a servo motor. Background Technology

[0002] Servo motors, as core actuators in industrial automation, are widely used in CNC machine tools, robotic arms, aerospace equipment, and high-end manufacturing production lines.

[0003] Existing mechanical limit mechanisms typically employ a fixed threshold design, making it impossible to adjust the protection sensitivity according to actual load requirements. For example, the same equipment requires different overload protection thresholds under different operating conditions (such as switching between light and heavy loads), which is difficult to meet with existing technologies. Therefore, we propose a mechanical limit mechanism for overload protection of servo motors. Utility Model Content

[0004] The purpose of this utility model is to provide a mechanical limit mechanism for overload protection of servo motors.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a servo motor overload protection mechanical limit mechanism, including a base plate, wherein a protection component and a brake component are provided on the upper end surface of the base plate;

[0006] The protection assembly includes a servo motor, a protection box, a drive shaft, a connecting block, a fixing plate, a locking block, a moving disk, a moving plate, a limiting frame, and a moving block. The side wall of the servo motor is connected to the side of the base plate. The center of the protection box is connected to the output end of the servo motor. The lower end face of the fixing plate is connected to the upper end face of the base plate. The side of the drive shaft is rotatably connected to the inner wall of the fixing plate. The center of the connecting block is connected to one end of the drive shaft. The side of the locking block engages with the side of the connecting block. The side of the moving block is connected to the side of the moving disk. The side of the limiting frame is slidably connected to the inner wall of the protection box. The side of the moving block is slidably connected to the inner wall of the limiting frame. The side of the moving plate is slidably connected to the inner wall of the protection box.

[0007] As a further embodiment of this utility model: the brake assembly includes a brake seat, a brake block, and a positioning rod. The lower end face of the brake seat is connected to the upper end face of the base plate, the bottom end of the positioning rod is connected to the upper end face of the brake seat, and the inner wall of the brake block is slidably connected to the surface of the positioning rod.

[0008] As a further embodiment of this utility model: an electric telescopic rod is connected to the side of the brake seat, and the telescopic end of the electric telescopic rod is connected to the side of the brake block.

[0009] As a further embodiment of this utility model: the side of the drive shaft is rotatably connected to the side of the brake seat, and the side of the brake block abuts against the side of the drive shaft.

[0010] As a further embodiment of this utility model: the inner wall of the protective box is threaded with a threaded rod, one end of which is rotatably connected to the side of the movable plate.

[0011] As a further embodiment of this utility model: a spring is connected to the side of the movable plate, and one end of the spring is connected to the side of the limiting frame.

[0012] As a further embodiment of this utility model: the side of the movable disk is slidably connected to the inner wall of the protective box, the side of the locking block is connected to the side of the movable disk, and the side of the locking block is slidably connected to the inner wall of the protective box.

[0013] Compared with the prior art, the beneficial effects of this utility model by adopting the above technical solution are as follows:

[0014] 1. This utility model allows for adjustment of the initial position of the movable plate via a threaded rod on the inner wall of the protective box, thereby changing the preload of the spring. The greater the preload, the higher the overload threshold for triggering the disengagement of the locking block, and vice versa. This adapts to the protection requirements under different load scenarios. After the overload is released, the spring force pushes the movable plate, limit frame, and movable disc to reset, and the locking block re-engages with the connecting block. The device can resume normal operation without manual reset, improving ease of use.

[0015] 2. This utility model uses a locking block and a connecting block in the protection component to engage. When the servo motor is overloaded, the resistance of the transmission shaft increases, pushing the moving disk to move the locking block until it disengages from the connecting block, forcibly cutting off the power transmission and preventing the motor from burning out due to continuous overload. This mechanical structure does not require electric drive and can still play a protective role in the event of power failure or electrical control system failure, with high reliability. The braking component pushes the brake block against the transmission shaft through an electric telescopic rod, using friction to quickly brake the transmission shaft, forming a "double insurance" with the mechanical limit. The electric control has a fast response speed and can trigger the brake instantly after detecting an overload signal, shortening the protection time.

[0016] Other advantages, objectives and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be taught from the practice of this invention. Attached Figure Description

[0017] Figure 1 This is an overall schematic diagram of an embodiment of the present utility model;

[0018] Figure 2This is a schematic diagram of the brake block in an embodiment of the present utility model;

[0019] Figure 3 This is a schematic diagram of the protective box in an embodiment of this utility model;

[0020] Figure 4 This is a schematic diagram of the movable disk in an embodiment of the present utility model;

[0021] Figure 5 This is a schematic diagram of the movable plate in an embodiment of the present utility model;

[0022] Figure 6 This is a schematic diagram of the limiting frame in an embodiment of the present utility model;

[0023] Figure 7 This is a schematic diagram of the card block in an embodiment of the present utility model;

[0024] Figure 8 This is a schematic diagram of the moving block in an embodiment of the present invention.

[0025] In the diagram: 1. Base plate; 2. Protective components; 21. Servo motor; 22. Protective box; 23. Threaded rod; 24. Drive shaft; 25. Connecting block; 26. Fixing plate; 27. Clamping block; 28. Moving plate; 29. ​​Moving plate; 210. Limiting frame; 211. Spring; 212. Moving block; 3. Brake assembly; 31. Brake seat; 32. Electric telescopic rod; 33. Brake block; 34. Positioning rod. Detailed Implementation

[0026] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of helping to understand this utility model, but does not constitute a limitation on this utility model.

[0027] Furthermore, the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0028] Please see the appendix Figure 1 - Appendix Figure 8 The present invention provides a mechanical limit mechanism for overload protection of a servo motor, comprising a base plate 1, wherein a protection component 2 and a brake component 3 are provided on the upper end surface of the base plate 1.

[0029] In embodiment 1, the protection component 2 includes a servo motor 21, a protection box 22, a drive shaft 24, a connecting block 25, a fixing plate 26, a locking block 27, a moving disk 28, a moving plate 29, a limit frame 210, and a moving block 212. The side wall of the servo motor 21 is connected to the side of the base plate 1. The center of the protection box 22 is connected to the output end of the servo motor 21. The lower end face of the fixing plate 26 is connected to the upper end face of the base plate 1. The side of the drive shaft 24 is rotatably connected to the inner wall of the fixing plate 26. The center of the connecting block 25 is connected to one end of the drive shaft 24. The side of the locking block 27 is engaged with the side of the connecting block 25. The side of the moving block 212 is engaged with the moving disk 28. The sides of the limit frame 210 are slidably connected to the inner wall of the protective box 22, the side of the moving block 212 is slidably connected to the inner wall of the limit frame 210, the side of the moving plate 29 is slidably connected to the inner wall of the protective box 22, the inner wall of the protective box 22 is threadedly connected to a threaded rod 23, one end of the threaded rod 23 is rotatably connected to the side of the moving plate 29, the side of the moving plate 29 is connected to a spring 211, one end of the spring 211 is connected to the side of the limit frame 210, the side of the moving disk 28 is slidably connected to the inner wall of the protective box 22, the side of the locking block 27 is connected to the side of the moving disk 28, and the side of the locking block 27 is slidably connected to the inner wall of the protective box 22.

[0030] Specifically, rotating the threaded rod 23 drives the moving plate 29 to move axially along the inner wall of the protective box 22 via the threaded transmission. When rotating the threaded rod 23 clockwise, the moving plate 29 moves forward, the pre-compression of the spring 211 increases, and the resistance threshold for triggering overload increases. When rotating counterclockwise, the threshold decreases.

[0031] After the overload is released, the spring 211 releases its elastic force, pushing the limit frame 210 to move the moving plate 28 back, the locking block 27 re-engages into the slot of the connecting block 25, and the moving plate 29 maintains its position through the threaded engagement of the threaded rod 23 with the protective box 22. The whole process requires no manual intervention.

[0032] In embodiment 2, the brake assembly 3 includes a brake seat 31, a brake block 33, and a positioning rod 34. The lower end face of the brake seat 31 is connected to the upper end face of the base plate 1, the bottom end of the positioning rod 34 is connected to the upper end face of the brake seat 31, the inner wall of the brake block 33 is slidably connected to the surface of the positioning rod 34, an electric telescopic rod 32 is connected to the side of the brake seat 31, the telescopic end of the electric telescopic rod 32 is connected to the side of the brake block 33, the side of the drive shaft 24 is rotatably connected to the side of the brake seat 31, and the side of the brake block 33 abuts against the side of the drive shaft 24.

[0033] Specifically, when the servo motor 21 is overloaded, the control system detects an abnormal current and sends a signal to the electric telescopic rod 32. The telescopic rod shortens and pushes the brake block 33 to slide downward along the positioning rod 34. The rubber surface of the brake block 33 comes into close contact with the drive shaft 24, generating a frictional torque that stops the drive shaft 24 from rotating. The positioning rod 34 ensures that the brake block 33 moves vertically, avoiding uneven braking force or component wear due to deviation.

[0034] The following section describes the structural design of the protection component and the overload threshold adjustment scenario. This scenario focuses on the specific structure of the protection component, the parameters of key components, and the implementation process of overload threshold adjustment. Specifically, it includes: selection and parameter design of core components, overload threshold adjustment circuit and operation procedure, and overload protection and automatic reset process.

[0035] I. Selection of Core Components and Parameter Design

[0036] The protection components mainly consist of the following elements:

[0037] Servo motor: Siemens 1FT7 series high-precision servo motor (rated power 3kW, rated speed 3000rpm) is selected. Its output end is fixedly connected to the central shaft of the protection box 22 through a coupling to ensure the coaxiality of power transmission.

[0038] Protective box: Made of aluminum alloy (6061-T6), with a wall thickness of 8mm. M12×1.5 threaded holes are provided on the inner wall for mounting the threaded rod 23. The inner diameter of the box is φ120mm, and the length is 150mm, ensuring sufficient sliding space for internal components such as the movable disc 28 and movable plate 29.

[0039] Threaded rod 23: Made of 45# steel, with a thread pitch of 1.5mm and a length of 80mm. One end is machined with a φ10mm smooth shaft section and is rotatably connected to the moving plate 29 through a deep groove ball bearing (type 6001) to avoid causing the moving plate to rotate synchronously when rotating.

[0040] Movable plate 29: 10mm thick Q235 steel plate, diameter φ118mm (0.5mm gap with the inner wall of the protective box), with a spring mounting seat (φ20mm×10mm) welded to the side; Spring 211 is made of 60Si2Mn spring steel, outer diameter φ25mm, wire diameter 3mm, free length 50mm, elastic coefficient k=50N / mm, initial pre-compression 10mm (preload 500N).

[0041] Both the locking block 27 and the connecting block 25 are made of 20CrMnTi carburized steel (surface hardness HRC58-62). The locking block has a trapezoidal cross section (top base 8mm, bottom base 12mm, height 10mm). The connecting block has a trapezoidal slot (tolerance fit H7 / g6) at the corresponding position to ensure the stability of the locking connection.

[0042] II. Overload Threshold Adjustment Circuit

[0043] To achieve precise adjustment of the overload threshold, the system is equipped with a manual adjustment mechanism and an auxiliary indicator circuit:

[0044] Manual adjustment mechanism: The outer end of the threaded rod 23 extends to the outside of the protective box 22 and is equipped with an anti-slip handwheel (diameter φ50mm, knurled surface). The handwheel is engraved with angle scales (each division corresponds to 1°, and the adjustment amount per division is ≈0.026mm when the thread pitch is 1.5mm).

[0045] Auxiliary indicating circuit: A pressure sensor (model LPS25H, range 0-2000N) is installed on the outer wall of the protective box and connected to an external digital display (displaying the spring preload value) via a signal line. During adjustment, rotating the handwheel drives the moving plate 29 to move axially. The pressure sensor provides real-time feedback on the preload of the spring 211. Adjustment stops when the value displayed on the digital display reaches the target threshold (e.g., 300N for light load and 800N for heavy load).

[0046] During normal operation, the servo motor 21 drives the moving disk 28 to rotate through the protective box 22. The locking block 27 engages with the connecting block 25, driving the transmission shaft 24 to rotate synchronously. When the load increases abnormally (such as the transmission shaft 24 being blocked), the radial resistance of the connecting block 25 to the locking block 27 exceeds the spring preload (F=k×Δx). The locking block 27 pushes the moving disk 28 to move axially along the limit frame 210 (the limit frame 210 is fixed to the inner wall of the protective box by a guide key, restricting its rotational freedom). When the moving disk 28 moves more than 5mm, the locking block 27 completely disengages from the slot of the connecting block 25, cutting off the power transmission and preventing the servo motor from burning out due to stall.

[0047] After the overload is released, the spring 211 releases its elastic force (F=k×(Δx initial - Δx overload)), pushing the limit frame 210 to move in the opposite direction. This causes the moving block 212 (φ8mm cylindrical pin) to reset the moving disk 28, and the locking block 27 to re-engage into the slot of the connecting block 25. The entire process requires no manual intervention, and the reset time is ≤0.5s.

[0048] Working principle:

[0049] First, after the servo motor 21 starts, it drives the protective box 22 to rotate through the output end. At the same time, the transmission shaft 24 is fixed to the base plate 1 through the fixing plate 26 and is driven to rotate by the power inside the protective box 22. The connecting block 25 is connected to one end of the transmission shaft 24, and the locking block 27 is locked on the side of the connecting block 25 and rotates synchronously with the transmission shaft 24. The moving disk 28 is slidably connected to the limit frame 210 through the moving block 212. The limit frame 210 is fixed to the inner wall of the protective box 22, and the moving disk 28 can move axially along the limit frame 210. The moving plate 29 is connected to the limit frame 210 through the spring 211. In the initial state, the spring 211 is compressed. The moving plate 29 is threadedly connected to the inner wall of the protective box 22 through the threaded rod 23. The initial position of the adjustable movable plate 29 is such that when the servo motor 21 is overloaded, the centrifugal force received by the limit frame 210 is greater than the elastic force of the spring 211, which in turn pushes the spring 211 to compress. The spring 211 generates a reverse elastic force, and the limit frame 210 drives the movable disk 28 to move through the movable block 212. When the movable disk 28 moves to a certain position, the locking block 27 disengages from the connecting block 25, cutting off the power transmission of the drive shaft 24 and preventing the servo motor 21 from being damaged due to overload. After the overload is released, the elastic force of the spring 211 pushes the movable plate 29 and the limit frame 210 to reset. The movable disk 28 moves back with the limit frame 210 through the movable block 212, and the locking block 27 re-engages with the connecting block 25, and the device returns to normal operation.

[0050] In normal operation, the brake seat 31 is fixed on the base plate 1, the positioning rod 34 is vertically installed on the top of the brake seat 31, and the brake block 33 is sleeved on the positioning rod 34 through the inner wall and can slide up and down along the positioning rod 34. The electric telescopic rod 32 is connected to the side of the brake seat 31, and its telescopic end is connected to the side of the brake block 33. In the initial state, the electric telescopic rod 32 is in the retracted state, and the brake block 33 maintains a gap with the transmission shaft 24, which does not affect the operation of the motor. When the servo motor 21 is overloaded, in addition to the protection component 2 being triggered, the electric telescopic rod 32 receives a signal and shortens, pushing the brake block 33 to slide down along the positioning rod 34. The side of the brake block 33 abuts against the transmission shaft 24, and applies braking force to the transmission shaft 24 through friction, forcing the transmission shaft 24 to stop rotating, further protecting the servo motor 21. After the overload fault is cleared, the electric telescopic rod 32 extends, driving the brake block 33 to reset along the positioning rod 34 and separate from the transmission shaft 24. The braking state is released, and the motor can be restarted. Thus, the entire working process ends.

[0051] The terms "front," "back," "left," "right," "top," and "bottom" all refer to the figures in the accompanying drawings. Figure 1 Based on.

[0052] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model.

[0053] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments.

[0054] For those skilled in the art, various changes, modifications, substitutions, and alterations to these embodiments without departing from the principles and spirit of this utility model will still fall within the protection scope of this utility model.

Claims

1. A servo motor overload protection mechanical limit mechanism, comprising a base plate (1), characterized in that: The upper surface of the base plate (1) is provided with a protective component (2) and a braking component (3). The protection component (2) includes a servo motor (21), a protection box (22), a drive shaft (24), a connecting block (25), a fixing plate (26), a locking block (27), a moving disk (28), a moving plate (29), a limit frame (210), and a moving block (212). The side wall of the servo motor (21) is connected to the side of the base plate (1). The center of the protection box (22) is connected to the output end of the servo motor (21). The lower end face of the fixing plate (26) is connected to the upper end face of the base plate (1). The drive shaft (24)... The side is rotatably connected to the inner wall of the fixed plate (26), the center of the connecting block (25) is connected to one end of the transmission shaft (24), the side of the locking block (27) is locked to the side of the connecting block (25), the side of the moving block (212) is connected to the side of the moving disk (28), the side of the limiting frame (210) is slidably connected to the inner wall of the protective box (22), the side of the moving block (212) is slidably connected to the inner wall of the limiting frame (210), and the side of the moving plate (29) is slidably connected to the inner wall of the protective box (22).

2. The servo motor overload protection mechanical limit mechanism according to claim 1, characterized in that: The brake assembly (3) includes a brake seat (31), a brake block (33) and a positioning rod (34). The lower end of the brake seat (31) is connected to the upper end of the base plate (1), the bottom end of the positioning rod (34) is connected to the upper end of the brake seat (31), and the inner wall of the brake block (33) is slidably connected to the surface of the positioning rod (34).

3. The servo motor overload protection mechanical limit mechanism according to claim 2, characterized in that: The brake seat (31) is connected to an electric telescopic rod (32) on its side, and the telescopic end of the electric telescopic rod (32) is connected to the side of the brake block (33).

4. The servo motor overload protection mechanical limit mechanism according to claim 2, characterized in that: The side of the drive shaft (24) is rotatably connected to the side of the brake seat (31), and the side of the brake block (33) abuts against the side of the drive shaft (24).

5. The servo motor overload protection mechanical limit mechanism according to claim 1, characterized in that: The inner wall of the protective box (22) is threaded with a threaded rod (23), one end of which is rotatably connected to the side of the movable plate (29).

6. The servo motor overload protection mechanical limit mechanism according to claim 1, characterized in that: A spring (211) is connected to the side of the movable plate (29), and one end of the spring (211) is connected to the side of the limiting frame (210).

7. The servo motor overload protection mechanical limit mechanism according to claim 1, characterized in that: The side of the movable disk (28) is slidably connected to the inner wall of the protective box (22), the side of the card block (27) is connected to the side of the movable disk (28), and the side of the card block (27) is slidably connected to the inner wall of the protective box (22).

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