Additional brake of passenger conveying device and passenger conveying device

Abstract

The invention discloses an additional brake of a passenger conveying device. The additional brake comprises a ratchet wheel assembly, a pressing plate, a base, a loading piece and an action mechanism. The ratchet wheel assembly comprises an outer ratchet wheel, a buffering piece, an inner ratchet wheel and a limiting piece. The inner ratchet wheel is arranged between the pressing plate and the base, and the friction combination surfaces of the inner ratchet wheel, the pressing plate and the base are preloaded through the loading piece; the base is connected with the second step chain wheel and rotates synchronously with the second step chain wheel; the ratchet wheel assembly can rotate relative to the second step chain wheel, the pressing plate and the base. The limiting piece is rigidly connected with the outer ratchet wheel, so that the outer ratchet wheel is relatively fixed on the outer circumference of the inner ratchet wheel; the outer ring of the inner ratchet wheel is provided with at least one tooth, the inner ring of the outer ratchet wheel is provided with at least one groove, and the teeth are contained in the grooves. The buffering piece is arranged on the side, close to the teeth of the inner ratchet wheel, rotating in the downward direction, in the groove, so that when the additional brake brakes, the side, rotating in the downward direction, of the teeth makes contact with the buffering piece.

Description

Technical Field

[0001] The present invention relates to the technical field of passenger conveyors, and particularly to an additional brake for a passenger conveyor and a passenger conveyor. Background Art

[0002] Escalators and moving walks are collectively referred to as passenger conveyors (hereinafter, escalators are taken as examples for illustration), and are all equipped with service brakes for stopping the escalator or keeping it in a stopped state. An additional brake is a redundant safety device that can be configured outside the service brake. When the escalator runs in reverse or descends at an excessive speed due to the failure of the service brake, it can stop the escalator.

[0003] The additional brake can be connected to the drive sprocket of the escalator steps in various forms such as shafts, gears, multi-row chains, etc. In the industry, the method of directly connecting to the drive component, i.e., the main shaft, is mostly adopted, which is generally called the main shaft braking type additional brake. This is a common typical structure of the additional brake. The braking components of the main shaft braking type additional brake generally include a ratchet wheel, a pressure plate, and a base. The pressure plate and the base rotate synchronously and coaxially with the main shaft. The ratchet wheel can rotate around the center of the main shaft relative to the pressure plate and the base. A preloading device is provided between the ratchet wheel and the pressure plate to clamp the two with a certain pressure. When the main shaft braking type additional brake brakes, the electromagnet loses power, and the elastic element pushes the ratchet rod or pawl to engage with the ratchet wheel or ratchet block through a connecting rod, restricting the rotation of the ratchet wheel. The main shaft continues to rotate under the action of inertia. Since the ratchet wheel rotates relative to the pressure plate and the base, under the preset pressure of the loading member, the ratchet wheel will immediately generate a sliding friction force on the pressure plate and the base, and continuously form a dynamic friction torque around the main shaft until the main shaft is braked. This braking torque has an approximate step-like mutation characteristic because it changes from a static friction torque to a dynamic friction torque instantaneously. To ensure that the preset braking torque of the additional brake can independently and reliably realize the function of braking the escalator, the set value of the braking torque of the additional brake is greater than the braking torque required for the full load, so as to ensure deceleration braking.

[0004] In addition, in GB16899-2011 "Safety Rules for the Construction and Installation of Escalators and Moving Walks"

[0005] It is clearly stipulated in 5.4.2.2.2 that: the additional brake should be able to effectively decelerate and stop an escalator and a moving walk with a braking load running downward, and keep it in a stationary state. The deceleration should not exceed 1 m / s² (filtered by a 4 Hz second-order Butterworth filter). Usually, a flywheel is configured at the high-speed end of the drive main engine of the escalator to provide a large moment of inertia, so that the escalator can run smoothly under different passenger loads during daily operation. When braking the escalator, configuring a flywheel can keep the braking deceleration within the preset range. The average deceleration during the whole process of braking by the additional brake generally can meet the requirement of not exceeding 1 m / s².

[0006] However, traditional main shaft braking type additional brakes are basically ratchet and pawl structures. When braking during descending with load and the additional brake acts to emergently stop the escalator instantaneously, when the pawl catches the ratchet, since the braking friction torque is a relatively large static friction torque preset according to the specifications of the escalator, when the additional brake brakes, the ratchet rotates relative to the driving main shaft immediately, and the static friction torque immediately changes into a dynamic friction torque. A huge impact will be generated during the short-time conversion process of the braking friction torque between the static and dynamic friction torques, causing a drastic change in the instantaneous value of the escalator braking deceleration; at the initial stage of braking, a sudden peak deceleration will appear on the ladder path, and then the braking deceleration tends to be stable; this peak deceleration at the initial stage will be significantly greater than the deceleration after tending to be stable, which is extremely likely to cause the risk of passengers falling due to the sudden change in speed at the initial stage of braking, and the peak deceleration is also likely to exceed the standard requirements. This problem has always been a difficult point in the industry. The reason for this phenomenon is usually generally attributed to the fact that the static friction torque between the ratchet and the pressure plate and the base before just starting to rotate is greater than the dynamic friction torque and the braking impact caused.

[0007] Chinese patent document CN201380081016.3 discloses a progressive additional brake structure. An outer ring is connected to the main shaft of the driving component and can rotate coaxially with the driving component; an inner block is arranged in the internal cavity defined by the outer ring. There is a first channel between the inner block and the outer ring, and a roller or a wedge block is arranged inside. Since the number of the rollers or wedge blocks is plural, in order to ensure the synchronous movement of each roller or wedge block, an actuator is arranged outside the inner block, and the rotation of the actuator is controlled by an electromagnet connected thereto, so that the rollers and the wedge blocks interact or disengage from each other to perform the functions of braking or releasing. When the additional brake brakes, the rotation of the actuator makes the wedge blocks move outward synchronously and catch between the outer ring and the inner block. Since the force applied to the wedge blocks is not based on the center of the rotating shaft relative to the outer circular surface of the wedge blocks outward, when the wedge blocks catch, the outer circular surface of the wedge blocks and the inner circular surface of the outer ring cannot be perfectly evenly stressed, and additional impact is inevitable during braking instantaneously. In addition, only relying on the local contact braking of several contact points between the wedge blocks and the inner circular surface of the outer ring, the magnitude of the braking torque that can be provided is limited.

[0008] Chinese Patent Document CN200910027135.6 discloses a technical solution in which one buffer block is added to each of the four brake blocks of the additional brake, and the impact force is absorbed by compressing the buffer block. An escalator is a highly integrated mechanical device. The braking device of the main shaft braking type additional brake is usually installed outside the step sprocket. Limited by the width of the truss, the general structure is relatively compact. Therefore, the contact surface between the brake block of the additional brake and the pawl is relatively small. This technical solution is to install a buffer block on the brake block. When the additional brake brakes, the pawl only acts on one brake block (including the buffer block), and the braking load of the entire escalator is concentrated on the brake block, and the acting force is very large. Therefore, the buffer block connected to the brake block only on one side cannot fully bear the braking load, and its shock mitigation effect and reliable service life are open to question.

[0009] In addition, to meet the standard requirements, traditional solutions also include increasing the flywheel inertia, controlling the braking torque of the main shaft braking type additional brake within a precise small range through tooling, and conducting a full-load braking test on the entire escalator to adaptively adjust the braking torque, etc. These traditional methods have high costs, limited effects, and require repeated adjustments, which are time-consuming and laborious. Summary of the Invention

[0010] To solve the above technical problems, the present invention provides an additional brake for a passenger conveyor, including a ratchet assembly, a pressing plate, a base, a loading member, and an operating mechanism; the ratchet assembly includes an outer ratchet, a buffer member, an inner ratchet, and a limiting member; the inner ratchet is arranged between the pressing plate and the base, and the friction joint surfaces of the inner ratchet with the pressing plate and the base are pre-loaded through the loading member; the base is connected to the second step sprocket and rotates synchronously; the ratchet assembly can rotate relative to the second step sprocket, the pressing plate, and the base; the limiting member is rigidly connected to the outer ratchet, so that the outer ratchet is relatively fixed on the outer circumference of the inner ratchet; at least one tooth is provided on the outer circumference of the inner ratchet, and at least one groove is provided on the inner circumference of the outer ratchet, and the tooth is received in the groove; the buffer member is arranged in the groove on the side rotating downward along the direction of the tooth of the inner ratchet, so that when the additional brake brakes, the side rotating downward along the direction of the tooth contacts the buffer member.

[0011] Preferably, friction elements are provided on the friction joint surfaces of the inner ratchet.

[0012] Preferably, friction elements are provided on the friction joint surfaces of the pressing plate or the base.

[0013] Preferably, the friction elements are fixed by fasteners or glue.

[0014] Preferably, the buffer member is fixed in the groove of the outer ratchet.

[0015] Preferably, the buffer member is fixed on the tooth of the inner ratchet.

[0016] Preferably, the actuating mechanism includes an electromagnet, an elastic element, a connecting rod, and a ratchet rod; the plunger of the electromagnet can move axially relative to the electromagnet; both ends of the connecting rod are rotatably connected to the ratchet rod and the plunger of the electromagnet respectively; a rotating shaft is provided in the middle of the ratchet rod, and the ratchet rod can rotate around the rotating shaft.

[0017] Preferably, the actuating mechanism includes an electromagnet, an elastic element, a connecting rod, and a pawl; the plunger of the electromagnet can move axially relative to the electromagnet; both ends of the connecting rod are rotatably connected to the pawl rod and the plunger of the electromagnet respectively; a rotating shaft is provided in the middle of the pawl, and the pawl can rotate around the rotating shaft.

[0018] Preferably, the actuating mechanism is connected to the frame of the passenger conveyor.

[0019] The present invention also provides a passenger conveyor, including the aforementioned additional brake.

[0020] Compared with the prior art, the present invention reduces the sudden change rate of the braking torque, reduces the peak deceleration during braking, and improves the safety during braking. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments:

[0022] Figure 1 It is a schematic top view of the upper part of a passenger conveyor including an additional brake;

[0023] Figure 2 It is a front elevation view of the additional brake of Embodiment 1;

[0024] Figure 3 It is a sectional view of the additional brake of Embodiment 1;

[0025] Figure 4 It is a front elevation view of the additional brake of the passenger conveyor during normal operation in Embodiment 1;

[0026] Figure 5 It is a front elevation view of the additional brake at the instant of braking in Embodiment 1;

[0027] Figure 6 It is a front elevation view of the additional brake after the braking response in Embodiment 1;

[0028] Figure 7 It is for Figure 5 a partial sectional view. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following describes the implementation manners of the present invention through specific embodiments. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific implementation manners. The details in this specification can also be applied based on different viewpoints, and various modifications or changes can be made without departing from the overall design concept of the invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited only to the specific embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary specific embodiments to those skilled in the art.

[0030] As Figure 1 shown, the passenger conveyor 12 includes a drive system 16 and an additional brake 10, and the additional brake 10 is actuated by reversing in the moving direction of the drive system. For ease of description, the passenger conveyor 12 is hereinafter referred to as the "escalator 12".

[0031] The escalator 12 and its components can be configured in various different ways. The escalator 12 further includes an escalator frame 18, and the drive system 16 is disposed in the escalator frame 18. The drive system 16 includes a plurality of drive components, and the drive components include a drive main machine 20, a transmission device 24 (such as a chain), a drive main shaft 26, a step sprocket, and a step chain 31. The step chain 31 includes a structure (not shown) to which a plurality of steps (not shown) can be attached. The drive main machine 20 provides power for the escalator 12. The drive main shaft 26 extends along an axial center line 33 between a first end portion and an opposite second end portion. The first end portion and the second end portion of the drive main shaft 26 rotate in a first bearing seat 27 and a second bearing seat 29 respectively. The first bearing 27 and the second bearing 29 are fixed on the escalator frame 18. The transmission device 24 is a chain. The transmission device 24 engages the first end portion of the drive main shaft 26. A first step sprocket 28 is connected to the first end portion of the drive main shaft 26. A second step sprocket 30 is connected to the second end portion of the drive main shaft 26. The teeth of the first step sprocket 28 and the second step sprocket 30 mesh with the step chain 31, so that the drive main shaft 26 drives the step chain 31 to move.

[0032] Embodiment 1

[0033] As Figures 2 to 7 shown, this embodiment provides an additional brake, which includes a ratchet assembly 60, a pressure plate 61, a base 58, a loading member 62, and an actuating mechanism 50;

[0034] The ratchet assembly 60 includes an outer ratchet 65, a plurality of buffer members 68, an inner ratchet 69, and a limit member 63;

[0035] The inner ratchet 69 is disposed between the pressing plate 61 and the base 58, and a preload is applied to the friction engagement surfaces of the inner ratchet 69 with the pressing plate 61 and the base 58 through a loading member 62;

[0036] The base 58 is connected to the second step sprocket 30 and rotates synchronously; the ratchet assembly 60 is rotatable relative to the second step sprocket 30, the pressing plate 61, and the base 58;

[0037] The limit member 63 is rigidly connected to the outer ratchet 65, such that the outer ratchet 65 is relatively fixed on the outer circumference of the inner ratchet 63;

[0038] At least one tooth 69b is provided on the outer circumference of the inner ratchet 69, and at least one groove 70 is provided on the inner circumference of the outer ratchet 65, and the tooth 69b is received in the groove 70;

[0039] The buffer member 68 is disposed in the groove 70 on the side that rotates in the downward direction adjacent to the tooth 69b of the inner ratchet, such that when the additional brake is braked, the side of the tooth 69b that rotates in the downward direction contacts the buffer member 68.

[0040] To increase the braking torque, a friction element 66 with a relatively high friction coefficient is provided between the inner ratchet 69, the pressing plate 61, and the base 58.

[0041] Solution one is to provide a friction element 66 on the mating surfaces of the inner ratchet 69 with the pressing plate 61 and the base 58; the friction element 66 is connected to the inner ratchet 69 by a bolt connection or by bonding.

[0042] Solution two is to provide a friction element 66 on the mating surfaces of the pressing plate 61, the base 58, and the inner ratchet 63; the friction element 66 is connected to the inner ratchet 69 by a bolt connection or by glue bonding.

[0043] Solution three is to provide a friction element 66 between the inner ratchet 69 and the pressing plate 61, and between the inner ratchet 63 and the base 58, and the friction element 66 is not connected to any of the above components by bolts, glue, etc. to form an integral component.

[0044] Figure 3 、 Figure 7 The internal structure of the ratchet assembly 60 is also shown. The outer ratchet 65 is relatively rotatable relative to the inner ratchet 69 based on the driving main shaft 26. A plurality of teeth 69b are provided on the outer circumference of the inner ratchet 69, and a plurality of grooves 70 are provided on the inner circumference of the outer ratchet 65, and the teeth 69b are received in the grooves 70. Inner teeth 65b of the outer ratchet 65 are formed between the plurality of grooves.

[0045] The shapes of the teeth 69b and the slots 70 can match, and there are several cavities for placing the buffer members 68 evenly distributed. To ensure the uniformity of the entire braking torque, the shapes and thicknesses of the buffer members 68 are consistent and are evenly distributed on the circumference of the ratchet wheel. This embodiment gives two solutions to keep the relative positions of the inner and outer ratchets fixed.

[0046] The first solution is to arrange limiting members 63 on both sides of the outer ratchet 65. The limiting members 63 are rigidly connected to the outer ratchet 65 through several connecting members 64. After connection, the outer ratchet 65 together with the buffer members 68 is relatively fixed on the outer circumference of the inner ratchet 69. Specifically, as Figure 2 、 Figure 3 shown in the structure.

[0047] The second solution is to arrange limiting members 63 on both sides of the inner ratchet 69. The limiting members 63 are rigidly connected to the inner ratchet 69 through several connecting members 64. After connection, the outer ratchet 65 together with the buffer members 68 is relatively fixed on the outer circumference of the inner ratchet 69.

[0048] As Figure 4 shown, the actuating mechanism 50 is composed of an electromagnet 51, an elastic element 52, a connecting rod 55 and a ratchet lever 54; the plunger of the electromagnet 51 can move axially relative to the electromagnet; both ends of the connecting rod 55 are rotatably connected to the ratchet lever 54 and the plunger of the electromagnet 51 respectively; a rotating shaft is arranged in the middle of the ratchet lever 54, and the ratchet lever 54 can rotate around the rotating shaft; when the passenger conveyor is running normally, under the electromagnetic force of the electromagnet 51, the connecting rod 55 pulls the ratchet lever 54 to rotate away from the ratchet assembly 60 of the braking mechanism; the braking mechanism together with the driving main shaft 26 rotates freely without restriction.

[0049] Figure 5 The operating conditions of the additional brake 10 are given when the escalator 12 reverses or descends overspeed: the electromagnet 51 is powered off, the electromagnet 51 no longer provides electromagnetic pull, the elastic element 52 returns to its initial length, pushes the plunger of the electromagnet 51 out, and rotates the ratchet lever 54 through the connecting rod 55. The top 54a of the ratchet lever 54 is engaged with the tooth groove 65a of the outer ratchet 65. The ratchet 60 is restricted from continuing to rotate, while the driving main shaft 26 continues to rotate due to the inertia caused by the load of the escalator. The inner teeth 65b of the outer ratchet 65 are restricted from rotating, the outer teeth 69b of the inner ratchet 69 continue to rotate, the cavity becomes smaller, directly compressing the buffer member 68, and the limiting members 63 on both sides of the ratchet can ensure that the buffer member 68 is compressed within the limited space. See Figure 6。The buffer member 68 is gradually compressed within a restricted space to form a gradually increasing elastic force, which can mitigate the impact caused by the huge mutation during the transition from static friction torque to dynamic friction torque, reduce the fluctuation of the instantaneous value of the braking deceleration, and is more conducive to achieving stability; reducing the fluctuation degree of the braking deceleration can lower the peak value of the deceleration, avoid the probability of passengers standing unsteadily at the initial stage of braking, and also make the deceleration more easily meet the standard requirements.

[0050] The present invention has been described in detail through specific embodiments and examples above, but these do not constitute a limitation to the present invention. Without departing from the principle of the present invention, those skilled in the art can also make many deformations and improvements, which should also be regarded as the protection scope of the present invention.

Claims

1. An additional brake for a passenger conveyance device, characterized in that, It includes a ratchet assembly, a pressure plate, a base, a loading member, and an actuating mechanism; The ratchet assembly includes an outer ratchet, a buffer member, an inner ratchet, and a limiting member; The inner ratchet is disposed between the pressure plate and the base, and the friction joint surfaces between the inner ratchet and the pressure plate and the base are pre-loaded by the loading member; The base is connected to the second step sprocket and rotates synchronously; the ratchet assembly can rotate relative to the second step sprocket, the pressure plate, and the base; The limiting member is rigidly connected to the outer ratchet, so that the outer ratchet is relatively fixed on the outer circumference of the inner ratchet; At least one tooth is provided on the outer circumference of the inner ratchet, and at least one groove is provided on the inner circumference of the outer ratchet, and the tooth is received in the groove; The buffer member is disposed in the groove on the side where the tooth of the inner ratchet rotates downward in the downward travel direction, so that when the additional brake is braked, the side where the tooth rotates downward in the downward travel direction contacts the buffer member.

2. The additional brake for a passenger conveyor according to claim 1, characterized in that, Friction elements are provided on the friction joint surface of the inner ratchet.

3. The additional brake of the passenger conveyor according to claim 1, characterized in that Friction elements are provided on the friction joint surface of the pressure plate or the base.

4. The additional brake of the passenger conveyor according to claim 2 or 3, characterized in that The friction elements are fixed by fasteners or glue.

5. The additional brake for a passenger conveyance device according to claim 1, wherein, The buffer member is fixed in the groove of the outer ratchet.

6. The additional brake of the passenger conveyor according to claim 1, characterized in that, The buffer member is fixed on the tooth of the inner ratchet.

7. The additional brake for a passenger conveyance device according to claim 1, wherein, The actuating mechanism includes an electromagnet, an elastic element, a connecting rod, and a ratchet rod; the electromagnet plunger can move axially relative to the electromagnet; both ends of the connecting rod are rotatably connected to the ratchet rod and the electromagnet plunger respectively; a rotating shaft is provided in the middle of the ratchet rod, and the ratchet rod can rotate around the rotating shaft.

8. The additional brake of the passenger conveyor according to claim 1, characterized in that, The actuating mechanism includes an electromagnet, an elastic element, a connecting rod, and a pawl; the electromagnet plunger can move axially relative to the electromagnet; both ends of the connecting rod are rotatably connected to the pawl rod and the electromagnet plunger respectively; a rotating shaft is provided in the middle of the pawl, and the pawl can rotate around the rotating shaft.

9. The additional brake of the passenger conveyor according to claim 1, characterized in that, The actuating mechanism is connected to the frame of the passenger conveyor.

10. A passenger conveyance device, characterized in that, It includes the additional brake according to any one of claims 1 to 9.

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