Service brake for a passenger transportation device

Abstract

This invention discloses a drum-type working brake device for a passenger transport device, comprising: a brake wheel for braking the passenger transport device; a brake arm assembly for braking or normal operation of the passenger transport device by pressing or releasing the brake wheel; a spring assembly for applying a preset elastic force to the brake arm assembly to press it closed; and an electromagnet assembly that, when energized, overcomes the spring force and moves the brake arm assembly away from the brake wheel; the electromagnet assembly is disposed between the brake wheel and the spring assembly. This invention not only reduces the risk of friction plate contact but also lowers the assembly precision requirements.

Description

Technical Field

[0001] This invention relates to the field of electric motors, and more specifically to a working brake for a passenger transport device. Background Technology

[0002] Passenger transport equipment, including escalators and moving walkways, must be equipped with service brakes as safety devices to ensure emergency braking in case of overspeed or malfunction alarms. Drum brakes are a commonly used type of brake for escalators.

[0003] Traditional drum brake mechanisms consist of a pin, a brake arm (including friction plates), a spring, and an electromagnet. When the electromagnet is energized, it overcomes the spring's force, opening the brake arm and allowing the escalator to operate normally. When braking is required, the electromagnet is de-energized, and the brake arm, under the action of the spring, presses against the brake wheel, thus braking the escalator. Traditional escalator drum brakes typically place the spring between the electromagnet and the friction plates, allowing for a compact arrangement.

[0004] The travel of an electromagnet is directly proportional to its cost. To reduce the cost of the braking system, the electromagnet's travel is usually set to a smaller value while still meeting usage requirements. However, this can lead to a reduction in the gap between the brake friction pads and the brake wheel. When the electromagnet travel is less than a critical value, the brake wheel may "lock up" due to various factors, resulting in the brake emitting smoke. These factors include: brake wheel expansion caused by increased temperature in the machine room, which reduces the gap between the brake arm friction pads and the brake wheel until they come into contact, causing abnormal braking; and large circular runout of the brake wheel during rotation, which reduces the gap with the brake arm friction pads in localized areas, leading to abnormal braking.

[0005] Currently, the industry largely relies on experience to address these issues in design; there are also some studies that detect friction plate wear. For example, CN104358810A mentions embedding copper bolts within the friction plates, which are connected to wires. When the friction plates wear down to the point where the copper bolts are exposed and in contact with the rotor core, the wires conduct, the main unit detects the signal, and the escalator stops operating. However, this approach has limited effectiveness in solving the problem of reduced clearance between the brake friction plates and the brake wheel.

[0006] This invention fully considers the elasticity of the brake arm and the influence of the clearance of the brake arm rotation pin. By optimizing the arrangement of the electromagnet and elastic element, the clearance between the brake friction plate and the brake wheel is improved in principle without changing the electromagnet stroke. This achieves the effect of low cost and high reliability of the escalator drum brake. Summary of the Invention

[0007] To solve the above-mentioned technical problems, the present invention provides a drum-type working brake device for a passenger transport device, comprising: Brake wheel, used to brake passenger transport equipment; The brake arm assembly enables the passenger transport device to brake or operate normally by pressing or releasing the brake wheel; A spring assembly is used to apply a preset elastic force to the brake arm assembly to press the brake arm assembly tightly; An electromagnet assembly, when energized, overcomes the force of the spring, causing the brake arm assembly to move away from the brake wheel; the electromagnet assembly is positioned between the brake wheel and the spring assembly.

[0008] Preferably, the brake wheel is fixedly connected to the motor rotor shaft of the drum brake device of the passenger transport device; The brake arm assembly includes a brake arm and a brake friction pad. One end of the brake arm is rotatably mounted on the motor housing. The brake friction pad is fixedly mounted on the brake arm and close to the brake wheel. The brake arm is driven to rotate around the hinge support point on the motor housing at one end to maintain the gap or press tightly against the surface of the brake wheel by the spring force and electromagnetic force applied to the brake arm by the spring assembly and the electromagnet assembly, respectively.

[0009] Preferably, the hinge support point of one end of the brake arm on the motor housing of the drum working brake device of the passenger transport device is a pin hinge device.

[0010] Preferably, the support point of one end of the brake arm on the motor housing is a ball joint.

[0011] Preferably, the brake friction pads are close to the outer circumference of the brake wheel and are arc-shaped; the brake arms and brake friction pads are arranged symmetrically around the brake wheel.

[0012] Preferably, the spring assembly is a compression spring assembly. After the electromagnet assembly is de-energized, the compression spring assembly immediately releases its compression force and drives the brake friction pads to contact the brake wheel for friction braking through the brake arm.

[0013] Preferably, the side of the brake friction pad that is close to the brake wheel has heat dissipation holes.

[0014] Compared with existing structures, the present invention can increase the gap between the working brake friction pad and the brake wheel near the hinge end of the brake arm, reduce the wear of the friction pad at this position, and avoid the risk of the friction pad and the brake wheel coming into contact when the brake is open. Attached Figure Description

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a front view of the basic structure of the working brake of the passenger transport device of the present invention.

[0016] Figure 2This is a top view of the basic structure of the working brake of the passenger transport device of the present invention.

[0017] Figures 3a-3b This is a simplified diagram of the forces acting on the electromagnet of the working brake of a passenger transport device in the open state, with the electromagnet outside the spring element and without considering the stiffness of the brake arm.

[0018] Figures 4a-4b This is a simplified diagram showing the force exerted on the electromagnet of the working brake of the passenger transport device of the present invention in the open state, with the electromagnet inside the spring element and without considering the stiffness of the brake arm.

[0019] Figure 5 It is the curve of brake arm deflection in the open state when the electromagnet of the working brake of the passenger transport device is outside the spring element and the stiffness of the brake arm is taken into account.

[0020] Figure 6 The curve showing the change in deflection of the brake arm in the open state when the electromagnet of the working brake of the passenger transport device of the present invention is inside the spring element and the stiffness of the brake arm is taken into account. Detailed Implementation

[0021] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification.

[0022] The escalator's working brake is installed on the motor assembly 1 and includes a brake wheel 2, a brake arm 3, an electromagnet force-bearing rod 4, a spring assembly 5, an electromagnet 6, a pin 7, and a cotter pin 8. In this embodiment, the brake wheel 2 is mounted on the motor rotor main shaft 12, and the brake arm 31 is hinged to the motor housing 2 via the pin 7 and the cotter pin 8. Alternatively, the support point of one end of the brake arm on the motor housing can also be a ball joint. The electromagnet force-bearing component 42 is fixed to the brake arm 31. A bolt 51 is fixed to the motor housing 1, and a spring 54 is fitted onto a screw 51; the spring force is adjusted via an end cap 53 and a nut 52. The electromagnet 6 is fixed to the motor housing 11 and acts on the electromagnet force-bearing component 42 via a push rod 61. A friction plate 32 is fixed to the brake arm 31.

[0023] Preferably, the screw 51 is fixed to the motor housing 11 by a threaded connection, and the electromagnet force-bearing component 42 is connected to the brake arm 31 by a threaded connection.

[0024] like Figure 2As shown, the working brake is in its initial state. At this time, the electromagnet 6 is not energized, the spring assembly 5 is not tightened to the set value, and there is a gap between the friction plate 32 and the brake wheel 12. After assembly, tightening the nut 52 makes the spring 54 reach the set value, and the brake arm 31 rotates around the pin 7, causing the friction plate 32 to press against the brake wheel 2. At this time, the working brake is in the braking state. If the electromagnet is energized at this time, the push rod 61 extends outward to contact the electromagnet force-bearing component 42, overcoming the spring force applied by the spring 54 and causing the brake arm to rotate away from the brake wheel 2. The friction plate 32 separates from the brake wheel 2, and the working brake is in the open state.

[0025] During the open state, due to the clearance fit between the pin 7 and the brake arm 31, the motor housing 11, and the force of the electromagnet 4, the gap between the friction plate 32 and the brake wheel at both ends of the pin 7 will not decrease monotonically.

[0026] The following is a detailed comparative analysis of the existing technology and the technical effects of the present invention in conjunction with the existing technology of the working brake of the passenger transport device.

[0027] To ensure smooth opening and closing of the brake arm, the hinge between the brake arm and the motor housing is a clearance fit during assembly. Assuming the brake arm is a rigid component, when it opens from its initial state, it undergoes two stages.

[0028] (1) When the electromagnet is arranged outside the spring element, see Figure 3: a) As shown in Figure 3(a), when the electromagnet is energized, it overcomes the spring resistance and pushes the brake arm. Due to the gap at point d, the brake arm will first rotate counterclockwise around the contact point c between the electromagnet push rod and the brake arm until the brake arm hole wall contacts the pin. At this time, the gap between the friction plate at point a and the brake wheel will decrease, and the gap at point b will increase.

[0029] (b) As shown in Figure 3(b), after the brake arm hole wall contacts the pin, the brake arm is restricted from continuing to rotate. At this time, the brake arm will rotate clockwise around the contact point between the brake arm and the pin. At this time, the gap at point a continues to decrease, and the gap at point b continues to increase. The brake arm remains stationary until the electromagnet stroke reaches the preset value.

[0030] At this point, the gap between the friction pad at point a and the brake wheel will be smaller than the gap at point b. If there are significant manufacturing or installation errors during assembly, the friction pad may come into contact with the brake wheel at point a.

[0031] (2) When the electromagnet is arranged inside the spring element, see Figure 4: a) As shown in Figure 4(a), when the electromagnet is energized, it overcomes the spring resistance and pushes the brake arm. Due to the gap at point d, the brake arm will rotate around the contact point between the spring element and the brake arm until the brake arm hole wall contacts the pin. At this time, the gap between the friction plate at point a and the brake wheel will increase, and the gap at point b will decrease.

[0032] (b) As shown in Figure 4(b), after the brake arm hole wall contacts the pin, the brake arm is restricted from continuing to rotate. At this time, the brake arm will rotate clockwise around the contact point between the brake arm and the pin. At this time, the gap at point a decreases and the gap at point b increases. The brake arm remains stationary until the electromagnet stroke reaches the preset value.

[0033] At this time, the gap between points a and b will not change monotonically, which can improve the influence of the gap fit on the gap between points a and b of the friction plate.

[0034] However, in actual production, the brake arm is not a completely rigid rod and will deform under the action of the electromagnet and elastic element. When considering the deflection change, the force diagrams for the two cases in the open state are as follows: Figures 5-6 .

[0035] (3) When the electromagnet is arranged outside the spring element, see Figure 5 At this point, the brake arm will generate a concave deflection curve under the combined action of the electromagnet and the spring element, causing the friction plate to rotate counterclockwise, reducing the gap at point a and increasing it at point b.

[0036] (4) When the electromagnet is arranged inside the spring element, see Figure 6 At this point, under the action of the electromagnet and spring elements, the brake arm will produce an upward convex deflection curve, increasing the gap between points a and b.

[0037] Considering factors such as clearance fit and brake arm deflection, if the electromagnet is installed on the outside of the spring element, it will cause a gap at point a, increasing the risk of contact between the friction pad and the brake wheel. However, if the electromagnet is placed on the inside of the spring element, it will increase the gap between points a and b, which not only reduces the risk of contact between the friction pad but also lowers the assembly precision requirements.

[0038] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A drum-type working brake device for a passenger transport device, characterized in that, include: Brake wheel, used to brake passenger transport equipment; The brake arm assembly enables the passenger transport device to brake or operate normally by pressing or releasing the brake wheel; A spring assembly is used to apply a preset elastic force to the brake arm assembly to press the brake arm assembly tightly; An electromagnet assembly, when energized, overcomes the force of the spring, causing the brake arm assembly to move away from the brake wheel; the electromagnet assembly is positioned between the brake wheel and the spring assembly.

2. The drum-type working brake device of the passenger transport device as described in claim 1, characterized in that, The brake wheel is fixedly connected to the motor rotor shaft of the drum working brake device of the passenger transport device. The brake arm assembly includes a brake arm and a brake friction pad. One end of the brake arm is rotatably mounted on the motor housing. The brake friction pad is fixedly mounted on the brake arm and close to the brake wheel. The brake arm is driven to rotate around the hinge support point on the motor housing at one end to maintain the gap or press tightly against the surface of the brake wheel by the spring force and electromagnetic force applied to the brake arm by the spring assembly and the electromagnet assembly, respectively.

3. The drum-type working brake device for a passenger transport device according to claim 2, characterized in that: The hinge support point of one end of the brake arm on the motor housing of the drum working brake device of the passenger transport device is a pin hinge device.

4. The drum-type working brake device for a passenger transport device according to claim 2, characterized in that: The support point of one end of the brake arm on the motor housing is a ball joint.

5. The drum-type working brake device for a passenger transport device according to claim 2, characterized in that: The brake friction pads are close to the outer circumference of the brake wheel and are arc-shaped; the brake arms and brake friction pads are arranged symmetrically around the brake wheel.

6. The drum-type working brake device for a passenger transport device according to claim 2, characterized in that: The spring assembly is a compression spring assembly. After the electromagnet assembly is de-energized, the compression spring assembly immediately releases its compression force and drives the brake friction pads to contact the brake wheel for friction braking through the brake arm.

7. The drum-type working brake device for a passenger transport device according to claim 2, characterized in that: The side of the brake friction pad that is close to the brake wheel has heat dissipation holes.

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