Friction disc combination type differential mechanical automatic brake and overload protection device

Abstract

This invention belongs to the field of aviation and aerospace hoisting mechanisms and winches, specifically relating to a friction disc combined slip mechanical automatic braking and overload protection device. It includes an input shaft and a brake shaft connected to the input shaft. The brake shaft is connected to the input end of an overload component, the output end of the overload component is connected to an automatic braking component, the automatic braking component is connected to an overrunning clutch component, and the overrunning clutch component is connected to the input shaft and the housing. This device integrates the input shaft, brake shaft, overload component, automatic braking component, overrunning clutch component, and housing into a cooperating mechanical whole. Through the connection and structural coupling between the components, it can simultaneously achieve three functions in the same device: speed difference adaptive braking, overload protection, and reverse locking to prevent slippage. It eliminates the need for external electrical control units, sensors, or hydraulic auxiliary devices, solving the problems of existing solutions having separate functions, large size and weight, and reliability limited by the electrical control unit.

Description

Technical Field

[0001] This invention belongs to the field of aviation and aerospace hoisting mechanisms and winches, specifically relating to a slip mechanical automatic braking and overload protection device based on a friction disc combination. Background Technology

[0002] In the aerospace and industrial sectors, hoisting mechanisms and winch systems need to have reliable lifting and lowering capabilities, and be able to stably maintain their current position under any operating conditions to prevent safety accidents such as slippage and accidental load drops. Currently, most mainstream solutions in the industry use power-off clutches or ratchet brake structures.

[0003] However, the pawl braking method has poor braking stability, is prone to jamming and failure, and can only achieve one-way locking, making it difficult to meet the dynamic braking and smooth lowering control requirements under complex vibration conditions. The power-off clutch has a large overall structure and is prone to failure and insufficient braking force during dynamic response. Its lowering process is highly dependent on motor energy consumption braking, which has high energy consumption and its reliability is severely restricted by the motor's operating conditions, posing a significant safety hazard in the event of power failure or motor failure.

[0004] Existing overload protection systems mostly adopt independent, separate structures with low coupling to the braking system. When the load is overloaded or the operating parameters are abnormal, the protection is prone to failure and the load may slip or roll away, making it impossible to reliably lock the load position under overload conditions.

[0005] For high-end applications such as aerospace and high-precision lifting, existing technologies still have the following prominent problems: In extreme operating environments such as vibration, wide temperature range, and strong radiation, the sensors and control units of electronically controlled braking devices are easily affected by environmental interference and may fail. Pawl brakes are prone to erroneous jamming or accidental unlocking due to high-frequency vibration, failing to meet the requirements for long-term reliable operation. The braking force of existing braking devices is mostly a fixed value preset by the factory, which cannot be dynamically matched according to the load weight and lowering speed. Under light loads, over-braking can easily occur, leading to jamming and impact, while under heavy loads, insufficient braking force can cause slippage. In abnormal operating conditions such as sudden power outages or motor failures, the braking force may also be insufficient. In the absence of power, the clutch often locks rigidly, resulting in a violent impact, or the delayed braking response causes the load to fall uncontrollably, making it difficult to achieve both smooth locking and shock-free protection at the same time. Existing technologies also require the independent configuration of multiple components such as braking devices, overload protectors, and anti-runaway mechanisms, resulting in long transmission chains, large overall weight, and high installation complexity, which makes it difficult to meet the stringent lightweight integration requirements of aerospace equipment. At the same time, the braking force of traditional friction braking devices is highly sensitive to the thickness of the friction pads. After the friction pads wear down, the brake clearance needs to be adjusted manually frequently, otherwise the braking force will quickly fade and runaway will occur, resulting in short maintenance cycles and high operation and maintenance costs. Summary of the Invention

[0006] To address the aforementioned shortcomings of existing technologies, this invention provides a slip mechanical automatic braking and overload protection device based on a friction disc combination, which solves the problems of existing braking devices being unable to automatically adjust the braking force according to the speed difference between the load and the input shaft, and being prone to slippage during power failure and overload.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A friction disc-based slip mechanical automatic braking and overload protection device is provided, including an input shaft and a brake shaft connected to the input shaft. The brake shaft is connected to the input end of the overload component, the output end of the overload component is connected to the automatic braking component, the automatic braking component is connected to the overrunning clutch component, and the overrunning clutch component is connected to the input shaft and the housing. The automatic braking assembly includes a follower disc and a power output disc connected to the follower disc. The follower disc is connected to the output end of an overload assembly. The end face of the follower disc facing the power output disc has multiple first grooves, and the end face of the power output disc facing the follower disc has multiple second grooves. The first grooves and second grooves are arranged opposite to each other. A receiving cavity is provided between the first grooves and the second grooves, and multiple rolling elements are arranged in the receiving cavity. A friction brake assembly is arranged between the power output disc and the housing, and an elastic element is arranged between the friction brake assembly and the power output disc.

[0008] The beneficial effects of adopting the above technical solution are as follows: By integrating the input shaft, brake shaft, overload assembly, automatic braking assembly, overrunning clutch assembly, and housing into a cooperating mechanical whole, and through the connection and structural coupling between the components, three functions—speed difference adaptive braking, overload protection, and reverse locking to prevent slippage—can be simultaneously realized in the same device without the need for external electronic control units, sensors, or hydraulic auxiliary devices. This solves the problems of existing solutions, such as separate functions, large size and weight, and reliability limitations imposed by the electronic control unit. Specifically, the input shaft and brake shaft serve as power input ends, transmitting the motor driving force to the overload assembly to provide the working power source for the entire device. The brake shaft also serves as the active drive end during the lowering process, achieving controllable unlocking of the braking state through the power transmitted by the input shaft. This allows the lowering process to fall freely without relying on the load's own weight, but rather to be actively controlled by the input power. The overload component is located between the brake shaft and the automatic braking component. Its input end receives the driving force input from the brake shaft, and its output end transmits the power to the automatic braking component. When the load resistance exceeds the preset transmission capacity of the overload component, the overload component slips internally, thereby cutting off the power transmission path. This prevents the driving force of the input shaft and brake shaft from being transmitted to the automatic braking component and the load end, protecting the motor and upstream transmission components from overload impact damage. At the same time, the automatic braking component remains in a braking state to prevent the load from losing its position lock at the moment of overload. The follower disc in the automatic braking assembly receives power input from the overload assembly, and the power output disc is used to connect the load. The first groove on the end face of the follower disc and the second groove on the end face of the power output disc are arranged opposite each other. A rolling element is arranged in the cavity between them, forming a conversion mechanism that converts the relative rotation between the follower disc and the power output disc into the axial relative displacement between them. When there is a difference between the speed of the load connected to the power output disc and the input speed of the follower disc, the rolling element changes position in the cavity, changing the axial distance between the follower disc and the power output disc, thereby adjusting the clamping force on the friction brake assembly, so that the braking torque automatically increases or decreases with the speed difference, and achieves adaptive adjustment of the load speed without relying on the intervention of the external electronic control unit. The friction brake assembly is positioned between the power output disc and the housing, utilizing the friction between the friction pairs to generate resistance to the rotation of the power output disc. Meanwhile, the elastic element, positioned between the friction brake assembly and the power output disc, continuously provides axial clamping force to the friction brake assembly, ensuring that it possesses a certain braking capability from the initial state. Furthermore, after the friction pads experience normal, minor wear, the rolling elements climb towards the shallow groove area within the first and second grooves, increasing the climbing distance to offset the axial clearance changes caused by wear. This prevents the clamping force of the friction brake assembly from diminishing due to wear, maintaining stable braking performance over long-term use without the need for frequent manual adjustments to the brake clearance.The overrunning clutch assembly has a unidirectional transmission characteristic. When the automatic braking assembly is running in the forward direction, it rotates freely without interference. When the automatic braking assembly is driven by the reverse torque of the load, it locks immediately, fixing the relevant rotating parts in the automatic braking assembly relative to the housing to prevent the load from rotating in the reverse direction. Thus, it can provide reverse locking protection for the load position locking in the case of motor power failure or fault conditions, preventing the load from accidentally slipping or falling.

[0009] Furthermore, the overload assembly includes an overload fixed plate and an overload moving plate that are alternately overlapped, with the overload moving plate connected to the follower plate; an overload disc spring is provided at one end of the overload fixed plate and the overload moving plate; the overload fixed plate is connected to the overload cup-shaped component, and the overload cup-shaped component is connected to the brake shaft; a first friction plate is provided between the overload moving plate and the overload fixed plate.

[0010] The beneficial effects of the above technical solution are as follows: The overload assembly uses an alternating overlapping arrangement of an overload fixed plate and an overload moving plate, with a first friction plate between them and an overload disc spring at one end. The axial clamping force of the disc spring generates static friction between the first friction plates of the overload fixed plate and the overload moving plate, thereby enabling the normal transmission of power from the brake shaft to the follower plate. When the load resistance exceeds the bearing range of this static friction force, the first friction plates between the overload fixed plate and the overload moving plate slip relative to each other, preventing the power of the brake shaft from continuing to be transmitted to the follower plate and the downstream automatic braking assembly. This automatically separates the input power from the load end, protecting the motor and upstream transmission components from abnormal overload impacts. At the same time, since the overload fixed plate is connected to the brake shaft through an overload cup-shaped component and the overload moving plate is only connected to the follower plate, the two sets of transmission relationships do not interfere with each other when slippage occurs. The follower plate and the automatic braking assembly connected to it still maintain their original braking and locking state, ensuring that the load will not lose its position lock and fall due to overload slippage.

[0011] Furthermore, the overrunning clutch assembly includes a one-way bearing and a pawl shaft disposed in the housing, with the inner ring of the one-way bearing connected to the pawl shaft.

[0012] The beneficial effects of adopting the above technical solution are as follows: the overrunning clutch assembly connects the inner ring of the one-way bearing to the pawl shaft fixed to the housing, so that the inner ring of the one-way bearing remains fixed relative to the housing, while the outer ring can rotate freely relative to the inner ring or lock in the reverse direction; when the automatic braking assembly is running in the forward direction, the outer ring of the one-way bearing rotates freely without generating braking interference, and does not affect the normal lifting and lowering operation of the device; when the motor is powered off or stops due to a fault, and the automatic braking assembly is driven by the reverse torque of the load, the outer ring of the one-way bearing immediately locks in the reverse direction. Since the inner ring is fixed to the housing through the pawl shaft and cannot rotate, the locking force of the outer ring is transmitted to the housing through the inner ring and the pawl shaft, so that the relevant components connected to the outer ring of the one-way bearing are firmly locked to the housing, thereby achieving mechanical reverse locking without the need for external power input.

[0013] Furthermore, the overrunning clutch assembly also includes an overrunning clutch cup, which is connected to the friction brake assembly, and the outer ring of the one-way bearing is connected to the overrunning clutch cup.

[0014] The beneficial effects of adopting the above technical solution are as follows: By connecting the overrunning clutch cup-shaped component to the friction brake assembly and the outer ring of the one-way bearing respectively, when the motor is driving normally, the forward rotation of the friction brake assembly is transmitted to the outer ring of the one-way bearing through the overrunning clutch cup-shaped component. The outer ring of the one-way bearing rotates freely relative to the inner ring without interference, and does not affect the lifting and lowering operation of the device. When the motor is powered off or stops due to a fault, and the reverse torque of the load is transmitted to the friction brake assembly, the reverse torque is directly transmitted to the outer ring of the one-way bearing through the overrunning clutch cup-shaped component. Since the inner ring of the one-way bearing is fixed to the housing and cannot rotate, the outer ring immediately locks in the reverse direction, so that the friction brake assembly is firmly locked to the housing.

[0015] Furthermore, the friction brake assembly includes a load brake friction pad pair and a lower holding friction pad pair. The load brake friction pad pair is located at one end near the power output disc, and the lower holding friction pad pair is located at one end near the overrunning clutch assembly. The load brake friction pad pair includes multiple alternately stacked load brake fixed discs and load brake moving discs, and the lower holding friction pad pair includes multiple alternately stacked lower holding fixed discs and lower holding moving discs. Second friction pads are provided between the load brake fixed discs and load brake moving discs, and between the lower holding fixed discs and lower holding moving discs.

[0016] The beneficial effects of adopting the above technical solution are as follows: The friction brake assembly sets the load brake friction pad pair at one end near the power output disc and the lower holding friction pad pair at one end near the overrunning clutch assembly, so that the two sets of friction pad pairs are arranged in different regions in the axial direction and each undertakes different braking functions. The load brake friction pad pair acts directly on one side of the power output disc to respond to the braking force demand generated by the load speed change, while the lower holding friction pad acts on the side near the overrunning clutch assembly to cooperate with the overrunning clutch assembly to provide holding braking force when locked in the reverse direction. At the same time, each set of friction pad pairs adopts a structure in which multiple fixed discs and moving discs are alternately stacked, and a second friction pad is set between the fixed discs and moving discs, so that the braking force is borne by multiple sets of friction surfaces. Compared with the single-piece friction structure, the effective friction area is significantly increased, and a larger braking torque output can be provided under the same axial clamping force. Meanwhile, the partitioned arrangement allows the two sets of friction pad pairs to operate without interference. The load braking friction pad pair automatically adjusts the braking torque based on the speed difference to achieve adaptive control of the load speed, while the lowering holding friction pad pair provides independent holding braking torque when the overrunning clutch component locks. This ensures smooth speed regulation during normal lowering and provides sufficient braking torque reserve for load position locking in the event of power failure or fault conditions.

[0017] Furthermore, both the first and second grooves are teardrop-shaped grooves.

[0018] Furthermore, the depth of the first groove and the second groove is 0.8 times the radius of the rolling element.

[0019] Furthermore, the follower disk is connected to the input terminal of the overload component via a spline.

[0020] Furthermore, the rolling element is a steel ball.

[0021] In summary, the beneficial effects of the friction disc combined slip mechanical automatic braking and overload protection device provided by this invention are as follows: (1) The device integrates the input shaft, brake shaft, overload assembly, automatic braking assembly, overrunning clutch assembly and housing into a cooperating mechanical whole. Through the connection and structural coupling between the components, the device can simultaneously realize three functions: speed difference adaptive braking, overload protection and reverse locking to prevent runaway. It does not require external electrical control unit, sensor or hydraulic auxiliary device. It solves the prominent problems in the prior art that the braking device cannot automatically adjust the braking force according to the speed difference between the load and the input shaft, is prone to runaway when the power is off and overloaded, and has separate functional components, large size and weight, and reliability is restricted by the electrical control unit.

[0022] (2) The overload assembly is set with an overload fixed plate and an overload moving plate overlapping each other, and an overload disc spring is set at one end. The axial clamping force of the overload disc spring is used to generate static friction between the first friction plate between the overload fixed plate and the overload moving plate, so that the power is transmitted normally from the brake shaft to the follower plate. When the load resistance exceeds the bearing range of the static friction, the overload fixed plate and the overload moving plate slip relative to each other, so that the power of the brake shaft cannot continue to be transmitted to the follower plate and the downstream automatic brake assembly, thereby automatically separating the input power from the load end and protecting the motor and upstream transmission components from abnormal overload impact. At the same time, since the overload fixed plate is connected to the brake shaft through the overload cup-shaped part and the overload moving plate is only connected to the follower plate, the two sets of transmission relationships do not interfere with each other when slippage occurs. The follower plate and the automatic brake assembly connected to it still maintain the original braking lock state, ensuring that the load will not lose its position lock and fall due to overload slippage.

[0023] (3) The overrunning clutch assembly is connected to the friction brake assembly through the overrunning clutch cup, and the outer ring of the one-way bearing is connected to the overrunning clutch cup, establishing a fixed torque transmission path between the friction brake assembly and the one-way bearing. When the motor is driving normally, the one-way bearing rotates freely in the forward direction with the automatic brake assembly, and the overrunning clutch cup rotates idling without interference, which does not affect the lifting and lowering operation of the device. When the motor is powered off or stops due to a fault, and the reverse torque of the load is transmitted to the friction brake assembly through the automatic brake assembly, the reverse torque is directly transmitted to the outer ring of the one-way bearing through the overrunning clutch cup. The one-way bearing is immediately locked in the reverse direction and transmits the braking force to the housing through its inner ring and pawl shaft, so that the friction brake assembly is fixed relative to the housing, realizing the linkage locking between the automatic brake assembly and the overrunning clutch assembly, ensuring that the reverse torque can be completely transmitted to the one-way bearing through the overrunning clutch cup, improving the locking response speed and reliability, and avoiding the structural complexity and transmission loss caused by adding external connecting parts.

[0024] (4) The friction brake assembly sets the load brake friction pad pair at one end near the power output disc and the lower holding friction pad pair at one end near the overrunning clutch assembly. The two sets of friction pad pairs are arranged in different regions in the axial direction and each undertakes different braking functions. The load brake friction pad pair acts directly on one side of the power output disc to respond to the braking force demand generated by the load speed change. The lower holding friction pad acts on one side near the overrunning clutch assembly to cooperate with the overrunning clutch assembly to provide holding braking force when locked in the reverse direction. At the same time, each set of friction pad pairs adopts a structure in which multiple fixed discs and moving discs are alternately stacked and a second friction pad is set between the fixed discs and moving discs. This makes the braking force borne by multiple sets of friction surfaces. Compared with the single-piece friction structure, the effective friction area is significantly increased, and a larger braking torque output can be provided under the same axial clamping force.

[0025] (5) The first groove on the end face of the follower disk and the second groove on the end face of the power output disk cooperate to accommodate the rolling element in the cavity, forming a conversion mechanism that converts the speed difference into axial displacement. When there is a difference between the speed of the load connected to the power output disk and the input speed of the follower disk, the rolling element changes position in the cavity, changing the axial distance between the follower disk and the power output disk, thereby adjusting the clamping force on the friction brake assembly, so that the braking torque automatically increases or decreases with the speed difference. Moreover, the groove adopts a teardrop-shaped structure and the depth is 0.8 times the radius of the rolling element, ensuring that the rolling element can slide smoothly in the groove to respond to the speed difference change, and can remain stable at the limit position without accidentally falling out, ensuring a smooth and reliable adaptive adjustment process. At the same time, the limiting structure set between the power output disk and the follower disk further restricts the range of motion of the rolling element, preventing the rolling element from falling out of the first groove and the second groove, ensuring the safety and reliability of the device in long-term operation. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the friction disc combined slip mechanical automatic braking and overload protection device of the present invention. Figure 2 This is a cross-sectional view of the friction disc combined slip mechanical automatic braking and overload protection device of the present invention; Figure 3 This is a schematic diagram of the overload component in the friction disc combined slip mechanical automatic braking and overload protection device of the present invention; Figure 4 This is a schematic diagram of the automatic braking component in the friction disc combined slip mechanical automatic braking and overload protection device of the present invention; Figure 5 This is a schematic diagram of the overrunning clutch assembly in the friction disc combined slip mechanical automatic braking and overload protection device of the present invention. Figure 6 This is a schematic diagram of the load brake friction pad pair and the lowering retaining friction pad pair in the friction disc combined slip mechanical automatic brake and overload protection device of the present invention. Figure 7 This is a schematic diagram of the follower disc in the friction disc combined slip mechanical automatic braking and overload protection device of the present invention; Figure 8 This is a schematic diagram of the power output disc in the friction disc combined slip mechanical automatic braking and overload protection device of the present invention; Figure 9 This is a schematic diagram of the overload condition of the slip mechanical automatic braking and overload protection device based on the friction disc combination of the present invention; Figure 10 This is a schematic diagram of the structure of the friction disc combined slip mechanical automatic braking and overload protection device of the present invention under lifting conditions. Figure 11 This is a schematic diagram of the structure of the friction disc combined slip mechanical automatic braking and overload protection device of the present invention under the working condition. The components are as follows: 1. Input shaft; 2. Brake shaft; 3. Overload assembly; 31. Overload fixed plate; 32. Overload moving plate; 33. Overload disc spring; 34. Overload cup-shaped component; 35. First friction pad; 4. Automatic braking assembly; 41. Follower plate; 42. Power output plate; 43. First groove; 44. Second groove; 45. Rolling element; 46. Friction brake assembly; 461. Load brake friction pad pair; 4611. Load brake fixed plate; 4612. Load brake moving plate; 462. Lowering holding friction pad pair; 4621. Lowering holding fixed plate; 4622. Lowering holding moving plate; 47. Elastic element; 48. Second friction pad; 5. Overrunning clutch assembly; 51. One-way bearing; 52. Pawl shaft; 53. Overrunning clutch cup-shaped component; 6. Housing. Detailed Implementation

[0027] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0028] like Figures 1 to 11 As shown, the friction disc-based slip mechanical automatic braking and overload protection device includes a housing 6, an input shaft 1, a brake shaft 2, an overload assembly 3, an automatic braking assembly 4, and an overrunning clutch assembly 5. The input shaft 1 is rotatably supported on the housing 6. The input shaft 1 and brake shaft 2 are fixedly connected by a spline, and the rotation of the input shaft 1 synchronously drives the brake shaft 2 to rotate. The brake shaft 2 is connected to the input end of the overload assembly 3, the output end of the overload assembly 3 is connected to the automatic braking assembly 4, the automatic braking assembly 4 is connected to the overrunning clutch assembly 5, and the overrunning clutch assembly 5 is connected to the input shaft 1 and the housing 6.

[0029] like Figure 2 , Figure 3 and Figure 4 As shown, the overload assembly 3 includes an overload fixed plate 31 and an overload moving plate 32 that are alternately overlapped. A first friction plate 35 is provided between the overload moving plate 32 and the overload fixed plate 31. An overload disc spring 33 is provided at one end of the overload fixed plate 31 and the overload moving plate 32. The overload disc spring 33 axially presses the overload fixed plate 31 and the overload moving plate 32 to generate static friction between them.

[0030] Brake shaft 2 and overload cup-shaped component 34 are fixedly connected via a keyway, and after assembly, brake shaft 2 and overload cup-shaped component 34 are integrated. Overload fixed plate 31 is fixedly connected to overload cup-shaped component 34, and overload moving plate 32 and follower plate 41 are connected via splines. During normal operation, brake shaft 2 drives overload fixed plate 31 to rotate via overload cup-shaped component 34, and overload fixed plate 31 drives overload moving plate 32 and follower plate 41 to rotate synchronously via static friction. When the load resistance on the follower plate 41 side exceeds the sum of static friction between overload fixed plate 31 and overload moving plate 32, the first friction plate 35 between overload moving plate 32 and overload fixed plate 31 slips relative to each other, and the power of brake shaft 2 cannot be transmitted to follower plate 41.

[0031] like Figure 2 and Figure 4As shown, the automatic braking assembly 4 includes a follower disc 41, a power output disc 42, multiple rolling elements 45, a friction brake assembly 46, and an elastic element 47, which is a disc spring. The follower disc 41 is connected to the output end of the overload assembly 3 (i.e., the overload drive disc 32). The power output disc 42 is used to connect the load, and it is coaxially arranged with the follower disc 41 and can rotate relative to it. Figure 4 , Figure 7 and Figure 8 As shown, the follower disk 41 has multiple first grooves 43 on its end face facing the power output disk 42, and the power output disk 42 has multiple second grooves 44 on its end face facing the follower disk 41. The first grooves 43 and second grooves 44 are opposite to each other, and a receiving cavity is provided between the first grooves 43 and second grooves 44. Multiple rolling elements 45, which may be steel balls, are respectively disposed in the receiving cavity. Both the first grooves 43 and second grooves 44 are teardrop-shaped grooves, including a deep groove area and a shallow groove area, and the depth of the groove is 0.8 times the radius of the rolling element 45. A limiting structure is also provided between the power output disk 42 and the follower disk 41 to prevent the rolling element 45 from disengaging from the first grooves 43 and second grooves 44. The friction brake assembly 46 is disposed between the power output disk 42 and the housing 6, and the elastic element 47 is disposed between the power output disk 42 and the friction brake assembly 46, with one end abutting against the end face of the power output disk 42 and the other end abutting against the moving disk end face of the friction brake assembly 46. Figure 4 and Figure 6 As shown, the friction brake assembly 46 includes a load brake friction pad pair 461 and a lower holding friction pad pair 462. The load brake friction pad pair 461 is located at one end near the power output disc 42, and the lower holding friction pad pair 462 is located at one end near the overrunning clutch assembly 5. The load brake friction pad pair 461 includes multiple alternately stacked load brake fixed discs 4611 and load brake moving discs 4612. The lower holding friction pad pair 462 includes multiple alternately stacked lower holding fixed discs 4621 and lower holding moving discs 4622. A second friction pad 48 is provided between the load brake fixed discs 4611 and load brake moving discs 4612 and between the lower holding fixed discs 4621 and lower holding moving discs 4622.

[0032] like Figure 2 and Figure 5 As shown, the overrunning clutch assembly 5 includes an overrunning clutch cup-shaped component 53, a one-way bearing 51, and a ratchet shaft 52. The ratchet shaft 52 is fixedly mounted on the housing 6, and the inner ring of the one-way bearing 51 is connected to the ratchet shaft 52. The overrunning clutch cup-shaped component 53 is fixedly connected to the friction brake assembly 46, and the outer ring of the one-way bearing 51 is fixedly connected to the overrunning clutch cup-shaped component 53. The one-way bearing 51 can achieve free rotation in the forward direction and mechanical locking in the reverse direction.

[0033] Example 1 Based on the above-mentioned slip mechanical automatic braking and overload protection device based on friction disc combination, this embodiment describes the lifting conditions of the device.

[0034] like Figure 10 As shown, after the motor starts, it drives the input shaft 1 to rotate in the forward direction. The input shaft 1 drives the brake shaft 2 to rotate synchronously in the forward direction via a spline. The brake shaft 2 drives the overload cup-shaped component 34, which is fixed to it via a keyway, to rotate synchronously. The overload cup-shaped component 34 drives the overload fixed plate 31, which is fixed to it, to rotate synchronously. Under the axial compression of the overload disc spring 33, the first friction plate 35 between the overload fixed plate 31 and the overload moving plate 32 generates static friction. Driven by this static friction, the overload fixed plate 31 drives the overload moving plate 32 to rotate synchronously. The overload moving plate 32 drives the follower plate 41 to rotate synchronously in the forward direction via a spline. When the follower plate 41 rotates in the forward direction, the rolling element 45, which is set between the follower plate 41 and the power output plate 42, rolls along the groove surfaces of the first groove 43 and the second groove 44 under the drive of the follower plate 41. Since the forward rotation direction of the follower disk 41 corresponds to the shallow groove area of ​​the teardrop-shaped groove, the rolling element 45 enters the shallow groove area of ​​the first groove 43 and the second groove 44 under the pushing action of centrifugal force and the follower disk 41. The axial depth corresponding to the shallow groove area is relatively large, and the axial distance between the follower disk 41 and the power output disk 42 is relatively large. The axial dimension of the receiving cavity between the two is relatively large, and the rolling element 45 does not exert axial extrusion force on the follower disk 41 and the power output disk 42. At this time, the follower disk 41 directly locks the power output disk 42 through the cooperation of the rolling element 45 and the shallow groove area of ​​the teardrop-shaped groove, so that a rigid connection is formed between the follower disk 41 and the power output disk 42. The two rotate synchronously without relative rotation, and the power output disk 42 rotates synchronously with the follower disk 41, driving the load connected to the power output disk 42 to be lifted smoothly.

[0035] During the lifting operation, there is no relative rotation between the follower disc 41 and the power output disc 42. The rolling element 45 is located in the shallow groove area of ​​the first groove 43 and the second groove 44. The axial clamping force borne by the friction brake assembly 46 is balanced with the lifting load, and the power output disc 42 maintains a smooth lifting under the braking torque of the friction brake assembly 46. At the same time, the one-way bearing 51 in the overrunning clutch assembly 5 is in a forward free rotation state. The outer ring of the one-way bearing 51 rotates forward with the overrunning clutch cup 53 and the friction brake assembly 46. The outer ring of the one-way bearing 51 rotates freely relative to the inner ring without any braking interference. The entire lifting process is a rigid transmission, without slippage or swerving, and the load is smoothly lifted to the target position.

[0036] Example 2 Based on the above-mentioned slip mechanical automatic braking and overload protection device based on friction disc combination, this embodiment describes the deployment conditions of the device.

[0037] like Figure 11As shown, after the motor starts, it drives the input shaft 1 to rotate in the reverse direction at a low speed. The input shaft 1 drives the brake shaft 2 to rotate in the reverse direction synchronously via a spline. The brake shaft 2 drives the follower disk 41 to rotate in the reverse direction synchronously via the transmission path of the cup-shaped component 34, the overload fixed disk 31, and the overload moving disk 32. When the follower disk 41 rotates in the reverse direction, the rolling element 45 rolls along the groove surfaces of the first groove 43 and the second groove 44 under the drive of the follower disk 41. Since the reverse rotation direction of the follower disk 41 corresponds to the deep groove area of ​​the teardrop-shaped first groove 43 and the second groove 44, the rolling element 45 enters the deep groove area of ​​the first groove 43 and the second groove 44 under the push of the follower disk 41. The axial depth corresponding to the deep groove area is small, and the axial distance between the follower disk 41 and the power output disk 42 is reduced accordingly, and the axial dimension of the receiving cavity between them is reduced. The rolling element 45 generates an axial compressive force on the follower disk 41 and the power output disk 42 in the deep groove area, pushing the power output disk 42 away from the follower disk 41. The axial movement of the power output disc 42 is transmitted to the friction brake assembly 46 via the elastic element 47, which reduces the compression of the elastic element 47 and the axial clamping force on the friction brake assembly 46. The normal pressure of the second friction pad 48 between the load brake fixed disc 4611 and the load brake moving disc 4612 in the load brake friction pad pair 461 is reduced, and the braking torque is reduced accordingly. After the braking torque is reduced, the load overcomes the residual braking torque of the friction brake assembly 46 under its own gravity, and drives the power output disc 42 to start rotating clockwise, so as to achieve a smooth lowering.

[0038] When the load accelerates downward during the lowering process, causing the clockwise rotational speed of the power output disc 42 to exceed the reverse input speed of the follower disc 41, a speed difference is generated between the follower disc 41 and the power output disc 42. This speed difference causes the rolling element 45 to roll from the deep groove section to the shallow groove section under the relative rotational drive of the follower disc 41 and the power output disc 42. As the rolling element 45 moves towards the shallow groove section, the axial distance between the follower disc 41 and the power output disc 42 gradually increases, the power output disc 42 moves back towards the follower disc 41, the compression of the elastic element 47 increases accordingly, the axial clamping force on the friction brake assembly 46 increases, the normal pressure of the second friction pad 48 between each load brake fixed disc 4611 and load brake moving disc 4612 in the load brake friction pad pair 461 increases, the braking torque automatically increases, and the increased braking torque generates reverse damping on the rotation of the power output disc 42, suppressing the accelerated downward movement of the power output disc 42. The process is continuously dynamically adjusted until the reverse input speed of the follower disk 41 and the clockwise speed of the power output disk 42 reach a dynamic balance. At this point, the braking torque is balanced with the load gravity torque, and the load is lowered smoothly at a constant speed.

[0039] Throughout the lowering process, the load brake friction pad pair 461 automatically adjusts the braking torque based on the speed difference between the follower disc 41 and the power output disc 42, achieving adaptive control of the load speed. The lowering holding friction pad pair 462 operates automatically when the overrunning clutch assembly 5 is not locked, without generating additional braking interference.

[0040] Example 3 Based on the above-mentioned slip mechanical automatic braking and overload protection device based on friction disc combination, this embodiment describes the overload condition of the device.

[0041] like Figure 9 As shown, during the lifting process, when the load weight connected to the power output disc 42 suddenly increases or the load resistance exceeds the preset normal operating range due to external factors, the load resistance borne by the overload moving disc 32 increases accordingly. This load resistance is transmitted to the overload moving disc 32 via the follower disc 41, generating a circumferential force on the first friction plate 35 at the contact surface between the overload moving disc 32 and the overload fixed disc 31. When this circumferential force exceeds the maximum static friction force generated by the overload disc spring 33 pressing between the overload fixed disc 31 and the overload moving disc 32, the static friction state between the overload moving disc 32 and the overload fixed disc 31 is broken, and the first friction plate 35 between them slides relative to each other at the contact surface. The overload fixed plate 31 continues to rotate with the brake shaft 2 and the overload cup-shaped component 34, while the overload moving plate 32 stops rotating or its speed decreases due to excessive load resistance. Slippage occurs between the two, which prevents the driving force of the brake shaft 2 from being transmitted to the follower plate 41 and the downstream automatic braking assembly 4 through the overload moving plate 32. The power transmission path is cut off at the overload assembly 3.

[0042] After the power transmission path is cut off, the motor and upstream transmission components no longer bear excessive resistance torque from the load end, avoiding motor overload burnout and transmission component torsion damage. Simultaneously, since the overload moving plate 32 and the follower plate 41 are splined, and the follower plate 41 is not actively driven when the overload moving plate 32 slips from the overload fixed plate 31, the follower plate 41 and the automatic braking assembly 4 maintain their original braking lock-up state under the load resistance torque. Specifically, under the load resistance torque, the follower plate 41 and the power output plate 42 exhibit a relative rotational tendency. The rolling element 45 enters the shallow groove area and increases the axial clamping force on the friction brake assembly 46. The friction brake assembly 46 generates sufficient braking torque to lock the power output plate 42, keeping the load in its current position without sagging.

[0043] If an overload occurs during the lowering process, the brake shaft 2 can overcome the slippage of the overload component 3 through the active drive of the input shaft 1, so that the overload moving plate 32 and the overload fixed plate 31 are pressed together again, and the power is transmitted to the follower plate 41 to achieve controlled lowering of the load.

[0044] Example 4 Based on the above-mentioned slip mechanical automatic braking and overload protection device based on friction disc combination, this embodiment describes the power failure and abnormal fault conditions of the device.

[0045] During the lifting or lowering process, if the motor suddenly loses power or malfunctions and stops, the input shaft 1 immediately loses its driving torque. The input shaft 1 and brake shaft 2 gradually stop rotating without driving force, and the follower disk 41 subsequently loses its active input power. At this time, the load connected to the power output disk 42 generates a reverse torque under its own gravity, driving the power output disk 42 to rotate in the lowering direction. Since the follower disk 41 has lost its active input power and is in a stationary or low-speed inertial rotation state, the rotation of the power output disk 42 creates a significant speed difference between the two. This speed difference drives the rolling element 45 to roll from the deep groove section to the shallow groove section along the groove surfaces of the first groove 43 and the second groove 44 within the receiving cavity. As the rolling element 45 enters the shallow groove area, the axial distance between the follower disc 41 and the power output disc 42 gradually increases. The power output disc 42 moves towards the follower disc 41, and the compression of the elastic element 47 gradually increases. After the compression of the elastic element 47 increases, its axial clamping force on the friction brake assembly 46 gradually increases. The normal pressure of the second friction pad 48 between each load brake fixed disc 4611 and load brake moving disc 4612 in the load brake friction pad pair 461 gradually increases, and the braking torque gradually increases accordingly. The increase of this braking torque is gradual, rather than instantaneous, so the impact on the transmission structure is small, avoiding structural damage that may be caused by rigid locking.

[0046] When the braking torque gradually increases to a level sufficient to balance the load's gravitational torque, the rotation of the power output disc 42 is stopped, and the load remains in its current position. If the load continues to increase and the downward trend continues, the rotation trend of the power output disc 42 intensifies, and the position of the rolling element 45 in the first groove 43 and the second groove 44 further approaches the shallow groove area, thus further increasing the braking torque and creating a braking effect that automatically intensifies with the increase of the load. At the same time, the braking torque generated by the automatic braking assembly 4 is transmitted to the overrunning clutch cup 53 via the friction brake assembly 46, which then transmits the braking torque to the outer ring of the one-way bearing 51. Since this torque is in the opposite direction, the one-way bearing 51 can switch from a free-rotating state to a locked state, with its outer ring locked relative to the inner ring. The inner ring of the one-way bearing 51 is fixed relative to the housing 6 by the pawl shaft 52 fixed to the housing 6. Therefore, the locking of the one-way bearing 51 fixes the overrunning clutch cup 53 and the friction brake assembly 46 connected to it relative to the housing 6, and the friction brake assembly 46 is securely locked to the housing 6. The reverse locking of the one-way bearing 51 and the adaptive braking of the friction brake assembly 46 form a dual braking protection. The braking torque of the two is superimposed on the power output disc 42, which firmly locks the current position of the load and completely prevents the occurrence of slippage and falling accidents.

[0047] Under the aforementioned power outage and fault conditions, the braking torque of the friction brake assembly 46 gradually increases with the increase of the speed difference, providing buffer protection for the transmission structure. The overrunning clutch assembly 5 provides reverse rigid locking, ensuring that when the braking torque of the friction brake assembly 46 is insufficient to completely suppress the load drop, the one-way bearing 51 provides the final mechanical locking guarantee. The dual protection mechanisms do not interfere with each other and complement each other, jointly achieving safe locking of the load position.

[0048] In summary, the friction disc combined slip mechanical automatic braking and overload protection device provided by this invention integrates the input shaft 1, brake shaft 2, overload component 3, automatic braking component 4, overrunning clutch component 5, and housing 6 into a cooperating mechanical whole. Through the connection and structural coupling between the components, it can simultaneously realize three functions in the same device: speed difference adaptive braking, overload protection, and reverse locking to prevent slippage. It does not require external electronic control unit, sensors, or hydraulic auxiliary devices, and solves the problems of existing solutions having separate functions, large size and weight, and reliability limited by electronic control unit.

Claims

1. A slip mechanical automatic braking and overload protection device based on a friction disc combination, characterized in that: It includes an input shaft (1) and a brake shaft (2) connected to the input shaft (1). The brake shaft (2) is connected to the input end of an overload assembly (3). The output end of the overload assembly (3) is connected to an automatic braking assembly (4). The automatic braking assembly (4) is connected to an overrunning clutch assembly (5). The overrunning clutch assembly (5) is connected to the input shaft (1) and the housing (6). The automatic braking assembly (4) includes a follower disc (41) and a power output disc (42) connected to the follower disc (41). The follower disc (41) is connected to the output end of the overload assembly (3). The follower disc (41) has a plurality of first grooves (43) on its end face facing the power output disc (42). The power output disc (42) has a plurality of second grooves (44) on its end face facing the follower disc (41). The first grooves (43) and the second grooves (44) are arranged opposite to each other. A receiving cavity is provided between the first grooves (43) and the second grooves (44). A plurality of rolling elements (45) are provided in the receiving cavity. A friction brake assembly (46) is provided between the power output disc (42) and the housing (6). An elastic element (47) is provided between the friction brake assembly (46) and the power output disc (42).

2. The slip mechanical automatic braking and overload protection device based on a friction disc combination as described in claim 1, characterized in that: The overload assembly (3) includes an overload fixed plate (31) and an overload moving plate (32) that are alternately overlapped. The overload moving plate (32) is connected to the follower plate (41). An overload disc spring (33) is provided at one end of the overload fixed plate (31) and the overload moving plate (32). The overload fixed plate (31) is connected to an overload cup-shaped component (34), and the overload cup-shaped component (34) is connected to the brake shaft (2). A first friction plate (35) is provided between the overload moving plate (32) and the overload fixed plate (31).

3. The slip mechanical automatic braking and overload protection device based on a friction disc combination as described in claim 1, characterized in that: The overrunning clutch assembly (5) includes a one-way bearing (51) and a pawl shaft (52) disposed in the housing (6), wherein the inner ring of the one-way bearing (51) is connected to the pawl shaft (52).

4. The slip mechanical automatic braking and overload protection device based on a friction disc combination as described in claim 3, characterized in that: The overrunning clutch assembly (5) further includes an overrunning clutch cup (53), which is connected to the friction brake assembly (46), and the outer ring of the one-way bearing (51) is connected to the overrunning clutch cup (53).

5. The slip mechanical automatic braking and overload protection device based on a friction disc combination as described in claim 1, characterized in that: The friction brake assembly (46) includes a load brake friction pad pair (461) and a lower holding friction pad pair (462). The load brake friction pad pair (461) is located at one end near the power output disc (42), and the lower holding friction pad pair (462) is located at one end near the overrunning clutch assembly (5). The load brake friction pad pair (461) includes multiple alternately stacked load brake fixed discs (4611) and load brake moving discs (4612), and the lower holding friction pad pair (462) includes multiple alternately stacked lower holding fixed discs (4621) and lower holding moving discs (4622). A second friction pad (48) is provided between the load brake fixed disc (4611) and the load brake moving disc (4612) and between the lower holding fixed disc (4621) and the lower holding moving disc (4622).

6. The slip mechanical automatic braking and overload protection device based on a friction disc combination as described in claim 1, characterized in that: Both the first groove (43) and the second groove (44) are teardrop-shaped grooves.

7. The slip mechanical automatic braking and overload protection device based on a friction disc combination as described in claim 6, characterized in that: The depth of the first groove (43) and the second groove (44) is 0.8 times the radius of the rolling element (45).

8. The slip mechanical automatic braking and overload protection device based on a friction disc combination as described in claim 1, characterized in that: The follower disk (41) is connected to the input end of the overload component (3) via a spline.

9. The slip mechanical automatic braking and overload protection device based on a friction disc combination as described in claim 1, characterized in that: The rolling element (45) is a steel ball.

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