Elevator bi-directional overspeed governor

Abstract

The application discloses a bidirectional speed limiter of an elevator, which comprises a rope wheel, a transmission mechanism, a main shaft, a speed detection mechanism, a motion mechanism, a rope clamping device, a spring and an electric switch; the speed detection mechanism comprises an upper platform, a lower platform, a swing arm, a weight and a swing connecting rod; when the elevator is descending, the rope wheel drives the main shaft to rotate in a first direction, the lower platform is provided with positive compensation relative to the rotating direction of the upper platform, and the positive compensation exerts an upward force on the lower platform; when the speed of the elevator reaches a first overspeed V1' in the descending direction, the motion mechanism triggers the electric switch to act; when the speed of the elevator reaches a second overspeed V2' in the descending direction, the motion mechanism triggers the rope clamping device to act; when the elevator is ascending, the rope wheel drives the main shaft to rotate in a second direction, the lower platform is provided with negative compensation relative to the rotating direction of the upper platform, and the negative compensation exerts a downward force on the lower platform; and when the speed of the elevator reaches a first overspeed V1 in the ascending direction, the motion mechanism triggers the electric switch to act.

Description

Technical Field

[0001] This invention relates to the field of elevator technology, and specifically to a bidirectional speed limiter for elevators. Background Technology

[0002] Normally, the elevator's upward and downward speeds are the same. The speed governor is used to detect overspeeding and trigger the brakes and safety clamps.

[0003] However, as elevators increase in speed and travel greater distances, the air pressure inside the elevator car changes drastically during ascent and descent, causing discomfort to passengers. Research has found that the human ear is more adaptable to pressure changes during ascent. To alleviate passenger discomfort, ultra-high-speed elevators must have their rated descent speed set lower than their rated descent speed.

[0004] Chinese patent application CN201280073318.1 discloses a technical solution in which the speed limiter has two independent speed detection mechanisms with different triggering speeds when the elevator car is moving up and down. The disclosed technology has the following problems: 1) The two detection mechanisms are isolated or transmit rotation via pawls, resulting in high noise and poor stability at high speeds. 2) The use of two detection mechanisms and actuation triggering mechanisms results in a large axial dimension, which is not conducive to the layout of the elevator machine room.

[0005] To address the aforementioned technical problems, Chinese patent application CN201310027081.X discloses a technical solution that converts the car's upward and downward speeds into the rotational speed of a speed detection mechanism using different belt drive ratios, achieving the design objective with a single speed detection mechanism. However, it suffers from the following issues: 1) Both the upward and downward transmission pulleys require clutches, resulting in high noise and poor stability during high-speed operation. 2) The simultaneous axial arrangement of the speed detection mechanism and belt drive mechanism leads to a large axial dimension, which is detrimental to the elevator machine room layout. Summary of the Invention

[0006] The technical problem to be solved by the present invention is how to provide a speed limiter with a simple structure and small axial dimension that can achieve inconsistent rated speeds for elevators going up and down.

[0007] To solve the above-mentioned technical problems, the present invention provides a bidirectional speed limiter for elevators, comprising a rope pulley, a transmission mechanism, a main shaft, a speed detection mechanism, an actuation mechanism, a rope clamping device, a spring, and an electrical switch;

[0008] The rope wheel drives the main shaft to rotate via a transmission mechanism; the speed detection mechanism rotates coaxially with the main shaft.

[0009] The speed detection mechanism includes an upper platform, a lower platform, a swing arm, a weight, and a swing linkage; the upper platform is fixedly connected to the main shaft, the lower platform can slide along the main shaft axis, and the upper platform is parallel to the lower platform; the weight is fixed to one end of the swing arm, the other end of the swing arm is connected to the upper platform through a revolute joint, one end of the swing linkage is connected to the middle of the swing arm through a ball joint, and the other end of the swing linkage is hinged to the lower platform through a ball joint;

[0010] There are three components: a swing arm, a weight, and a swing link. The connection points between the swing arm and the upper platform form a first equilateral triangle, and the connection points between the swing link and the lower platform form a second equilateral triangle. When the main shaft is stationary, the vertical projections of the corresponding sides of the first and second equilateral triangles are not parallel.

[0011] The main shaft has a spring stroke adjustment mechanism, and the spring is disposed between the lower platform and the spring stroke adjustment mechanism; the actuation mechanism is connected to the lower platform.

[0012] When the elevator descends, the sheave drives the main shaft to rotate in the first direction, and the main shaft drives the speed detection mechanism to rotate. The rotation direction of the lower platform relative to the upper platform provides positive compensation to the lower platform, and the positive compensation applies an upward force to the lower platform. The weight moves outward under the action of centrifugal force, which drives the lower platform to move upward. When the elevator speed reaches the first downward overspeed speed V1', the actuation mechanism triggers the electrical switch to operate. When the elevator speed reaches the second downward overspeed speed V2', the actuation mechanism triggers the rope clamping device to operate.

[0013] When the elevator goes up, the sheave drives the main shaft to rotate in the second direction. The main shaft drives the speed detection mechanism to rotate. The rotation direction of the lower platform relative to the upper platform provides negative compensation to the lower platform. The negative compensation applies a downward force to the lower platform. The weight moves outward under the action of centrifugal force, which drives the lower platform to move upward. When the elevator speed reaches the first overspeed V1, the action mechanism triggers the electrical switch to operate.

[0014] Among them, the downbound rated speed V0' < downbound first overspeed V1' < downbound second overspeed V2' < upbound rated speed V0 < upbound first overspeed V1.

[0015] Preferably, the transmission mechanism is a bevel gear, the rotation axis of the rope pulley is horizontal, the rotation axis of the main shaft is vertical, and the rotation axis of the rope pulley and the rotation axis of the main shaft are perpendicular to each other.

[0016] Preferably, the rotational speed of the sheave is the same as that of the main shaft.

[0017] Preferably, the first direction is clockwise and the second direction is counterclockwise; when the spindle rotates clockwise, the lower platform rotates counterclockwise relative to the upper platform, providing positive compensation to the lower platform; when the spindle rotates counterclockwise, the lower platform rotates clockwise relative to the upper platform, providing negative compensation to the lower platform.

[0018] Preferably, the first direction is counterclockwise and the second direction is clockwise; when the spindle rotates counterclockwise, the lower platform rotates clockwise relative to the upper platform, providing positive compensation to the lower platform; when the spindle rotates clockwise, the lower platform rotates counterclockwise relative to the upper platform, providing negative compensation to the lower platform.

[0019] Preferably, the actuation mechanism includes a bushing, a first rocker arm, a second rocker arm, a bracket, and an actuation rod; the lower platform is connected to the bushing via a bearing to maintain consistent axial displacement and allow relative rotation; the bushing is hinged to the first rocker arm, the two ends of the first rocker arm are respectively hinged to the second rocker arm and the actuation rod 53, the second rocker arm is hinged to the bracket, and the bracket is fixedly mounted on the housing of the transmission mechanism.

[0020] Preferably, the speed detection mechanism further includes three parallel connecting rods, which are connected to the upper platform and the lower platform respectively via ball joints; the connection points of the parallel connecting rods and the upper platform form a third equilateral triangle, and the connection points of the parallel connecting rods and the lower platform form a fourth equilateral triangle; when the main shaft is in a stationary state, the projections of the corresponding sides of the third and fourth equilateral triangles in the vertical direction are not parallel.

[0021] Compared with the prior art, the present invention uses only one speed detection mechanism. Through the spatial structure design of the speed detection mechanism, it achieves negative compensation of the force exerted on the lower platform in the direction of frame rotation when the elevator is going up (high speed), and positive compensation of the force exerted on the lower platform in the direction of frame rotation when the elevator is going down (slow speed). No additional adjustment parts or mechanisms are required, which can reduce the size of the mechanism and the operating noise. Attached Figure Description

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0023] Figure 1 This is a schematic diagram of the elevator bidirectional speed limiter structure in Example 1;

[0024] Figure 2 These are schematic diagrams of the two speed detection mechanisms in Example 1;

[0025] Figure 3 This is a schematic diagram illustrating the positive and negative compensation implemented by the speed detection mechanism in Example 1;

[0026] Figure 4A schematic diagram of the elevator bidirectional speed limiter operation in Example 1, showing the elevator's upward and downward movement;

[0027] Figure 5 This is a schematic diagram of the speed detection mechanism driving the motion mechanism in Example 1. Detailed Implementation

[0028] 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. The present invention can also be implemented or applied through different specific embodiments, and the details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, unless otherwise specified, the following embodiments and features 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 to the specific embodiments set forth 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 embodiments to those skilled in the art.

[0029] Example 1

[0030] like Figure 1 As shown, this embodiment provides a bidirectional speed limiter for elevators, including a pulley 1, a transmission mechanism 7, a main shaft 2, a speed detection mechanism 3, an actuation mechanism 5, a rope clamping device 8, a spring 6, and an electrical switch (not shown in the figure).

[0031] The transmission mechanism 7 is a bevel gear. The rotation axis of the rope wheel 1 is horizontal, and the rotation axis of the main shaft 2 is vertical. The rotation axis of the rope wheel 1 and the rotation axis of the main shaft 2 are perpendicular to each other.

[0032] When the elevator car moves up or down, the car drives the pulley 1 to rotate via the speed governor wire rope (not shown in the figure). The pulley 1 drives the main shaft 2 to rotate via the bevel gear pair. The main shaft 2 and the pulley 1 rotate at the same speed.

[0033] like Figure 2As shown, the speed detection mechanism includes an upper platform 31, a lower platform 32, a swing arm 33, a weight 34, and a swing link 35. The upper platform 31 is fixedly connected to the main shaft 2, and the lower platform 32 is connected to the main shaft 2 via a sliding bearing. The lower platform 32 can slide along the axial direction of the main shaft 2, and the upper platform 31 is parallel to the lower platform 32. The weight 34 is fixed to one end of the swing arm 33, and the other end of the swing arm 33 is connected to the upper platform 31 via a revolute joint 44. One end of the swing link 35 is connected to the middle of the swing arm 33 via a ball joint 45, and the other end of the swing link 35 is hinged to the lower platform 32 via a ball joint 46. The main shaft 2 has a spring stroke adjustment mechanism, and the spring 6 is disposed between the lower platform 32 and the spring stroke adjustment mechanism.

[0034] like Figure 2 As shown in diagram b, there are three components: a swing arm, a weight, and a swing linkage. The connection points between the swing arm and the upper platform form a first equilateral triangle, and the connection points between the swing linkage and the lower platform form a second equilateral triangle. When the main shaft is stationary, the vertical projections of corresponding sides of the first and second equilateral triangles are not parallel. This feature can be used to... Figure 3 As clearly seen in b, the swing arm, the weight, and the swing linkage constitute the first set of parallel branches, giving the lower platform two degrees of freedom relative to the upper platform: vertical translation and rotation about the main axis.

[0035] Preferably, a second set of parallel branches can also be constructed, such as Figure 2 As shown in Figure a, the speed detection mechanism also includes three parallel connecting rods 41. These parallel connecting rods 41 are connected to the upper platform 31 and the lower platform 32 via ball joints 42 and 43, respectively. The connection points of the parallel connecting rods 41 and the upper platform 31 form a third equilateral triangle, and the connection points of the parallel connecting rods 41 and the lower platform 32 form a fourth equilateral triangle. When the main shaft 2 is stationary, the vertical projections of corresponding sides of the third and fourth equilateral triangles are not parallel. These two sets of parallel branches are redundant; a single first set of parallel branches can be used in a spatial structure, or two sets of redundant parallel branches can be used.

[0036] like Figure 3 As shown in b, since the vertical projections of corresponding sides of the first and second equilateral triangles are not parallel, meaning the first and second equilateral triangles have a preset initial angle; and since the vertical projections of corresponding sides of the third and fourth equilateral triangles are not parallel, meaning the third and fourth equilateral triangles also have a preset initial angle. This means that if the tilt direction of the swing link or parallel link is to the right, when the upper platform begins to rotate counterclockwise, the lower platform, rotating clockwise relative to the upper platform, will exert a downward force on the lower platform, increasing the distance between the upper and lower platforms, such as... Figure 3As shown in diagram a; when the upper platform begins to rotate clockwise, the lower platform rotates counterclockwise relative to the upper platform, exerting an upward force on the lower platform, thus reducing the distance between the upper and lower platforms, as shown in diagram a. Figure 3 As shown in c. Applying a downward force to the lower platform is defined as providing negative compensation to the lower platform, and applying an upward force to the lower platform is defined as providing positive compensation to the lower platform.

[0037] Furthermore, if the tilt direction of the swing link or parallel link is tilted to the right, when the upper platform starts to rotate counterclockwise, the lower platform will exert an upward force on the lower platform when it rotates clockwise relative to the upper platform, thus reducing the distance between them; when the upper platform starts to rotate clockwise, the lower platform will exert a downward force on the lower platform when it rotates counterclockwise relative to the upper platform, thus increasing the distance between them.

[0038] Therefore, the corresponding rotation direction and the tilt direction of the corresponding swing link or parallel link can be selected according to the arrangement of the elevator car and the speed limiter. The ultimate goal is to ensure that when the elevator is going down, the rotation direction of the lower platform relative to the upper platform provides positive compensation to the lower platform; and when the elevator is going up, the rotation direction of the lower platform relative to the upper platform provides negative compensation to the lower platform.

[0039] In the latter part of this embodiment, the rotation direction of the main shaft is clockwise when the elevator is going down and counterclockwise when the elevator is going up. That is, the first direction is clockwise and the second direction is counterclockwise.

[0040] like Figure 2 As shown in Figure a, the actuation mechanism includes a bushing 51, a first rocker arm 52, a second rocker arm 55, a bracket 54, and an actuating rod 53; the lower platform 32 is connected to the bushing 51 through a bearing 56, maintaining consistent axial displacement and being able to rotate relative to each other; the bushing 51 is hinged to the first rocker arm 52, and the two ends of the first rocker arm 52 are respectively hinged to the second rocker arm 55 and the actuating rod 53; the second rocker arm 55 is hinged to the bracket 54, and the bracket 54 is fixedly mounted on the housing of the transmission mechanism.

[0041] like Figure 5 As shown, when the lower platform 32 moves the bushing 51 upward, it causes the actuating rod 53 to have an upward displacement. When the displacement of the actuating rod 53 reaches the first displacement S1, it will trigger the electrical switch (not shown in the figure) to activate, thereby engaging the brake and restricting the movement of the elevator car. When the displacement of the actuating rod 53 reaches the second displacement S2, it will trigger the rope clamping device to clamp the speed governor wire rope, thereby pulling the car safety gear to stop the elevator car.

[0042] The following explains the operating speed of the bidirectional speed limiter for both upward and downward travel of the elevator.

[0043] The elevator has a preset rated downward speed V0' and a rated upward speed V0. The bidirectional speed limiter has preset first overspeed downward speed V1', second overspeed downward speed V2', and first overspeed upward speed V1. Among them, the rated downward speed V0' < first overspeed downward speed V1' < second overspeed downward speed V2' < rated upward speed V0 < first overspeed upward speed V1.

[0044] like Figure 4 As shown in diagram a, when the elevator descends, the sheave drives the main shaft to rotate clockwise, which in turn rotates the speed detection mechanism. The weight moves outward under centrifugal force, and the swing arm drives the swing linkage. The lower platform, relative to the upper platform, must overcome the spring pressure to move upward while simultaneously rotating counter-clockwise relative to the upper platform, providing positive compensation. As the elevator speed increases, when it reaches the first downward overspeed V1', the centrifugal force driving the lower platform upward is denoted as F1', causing the actuator rod to reach the first displacement S1, triggering the corresponding electrical switch. At this time, the angle between the lower platform and the upper platform is a1', the positive compensation distance is δX1', the displacement of the lower platform is X1', and the spring force of spring 6 is F6' = K6X1'. When the elevator speed continues to increase to the second downward overspeed V2', the centrifugal force driving the lower crossbar upward is denoted as F2', causing the actuator rod to reach the second displacement S2, triggering the rope clamping device. At this moment, the angle between the lower platform and the upper platform is a1, the positive compensation distance is δX1, the displacement of the lower platform is X1, and the spring force of spring 6 is F6 = K6X1.

[0045] like Figure 4As shown in Figure b, when the elevator ascends, the speed governor pulley drives the main shaft to rotate counterclockwise, which in turn drives the speed detection mechanism to rotate. The weight moves outward under centrifugal force, and the swing arm drives the swing linkage. The lower platform, relative to the upper platform, must overcome the spring pressure to move upward, and simultaneously rotates clockwise relative to the upper platform, providing negative compensation. When the elevator's ascending speed reaches the first downward overspeed V1' and the second downward overspeed V2', the angles of the lower platform relative to the upper platform are a2' and a2', respectively, and the negative compensation distances are δX2' and δX2', respectively. The displacements of the lower platform are X2' and X2'. Since δX2' < δX2' < 0 < δX1' < δX1', the spring force F6 = K6X2 > F6' = K6X2' > F6'' = K6X2'. At this time, the centrifugal forces F2' and F2' of the weight are insufficient to overcome the spring force F6, and the preset travel cannot be reached, thus failing to trigger the electrical switch and the rope clamping device. As the elevator speed increases, when the elevator speed reaches the first upward overspeed speed V1, the centrifugal force F1 of the weight increases. By reasonably designing the displacement of the lower platform, F1 can be made equal to F6 at this time. Therefore, when the elevator speed reaches the first upward overspeed speed V1, the electrical switch will be triggered, and the car will be stopped by the brake.

[0046] 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 bidirectional speed limiter for elevators, characterized in that, It includes a rope pulley, transmission mechanism, main shaft, speed detection mechanism, actuation mechanism, rope clamping device, spring, and electrical switch; The rope wheel drives the main shaft to rotate via a transmission mechanism; the speed detection mechanism rotates coaxially with the main shaft. The speed detection mechanism includes an upper platform, a lower platform, a swing arm, a weight, and a swing linkage; the upper platform is fixedly connected to the main shaft, the lower platform can slide along the main shaft axis, and the upper platform is parallel to the lower platform; the weight is fixed to one end of the swing arm, the other end of the swing arm is connected to the upper platform through a revolute joint, one end of the swing linkage is hinged to the middle of the swing arm through a ball joint, and the other end of the swing linkage is hinged to the lower platform through a ball joint; There are three components: a swing arm, a weight, and a swing link. The connection points between the swing arm and the upper platform form a first equilateral triangle, and the connection points between the swing link and the lower platform form a second equilateral triangle. When the main shaft is stationary, the vertical projections of the corresponding sides of the first and second equilateral triangles are not parallel. The main shaft has a spring stroke adjustment mechanism, and the spring is disposed between the lower platform and the spring stroke adjustment mechanism; the actuation mechanism is connected to the lower platform. When the elevator descends, the sheave drives the main shaft to rotate in the first direction, and the main shaft drives the speed detection mechanism to rotate. The rotation direction of the lower platform relative to the upper platform provides positive compensation to the lower platform, and the positive compensation applies an upward force to the lower platform. The weight moves outward under the action of centrifugal force, which drives the lower platform to move upward. When the elevator speed reaches the first downward overspeed speed V1', the actuation mechanism triggers the electrical switch to operate. When the elevator speed reaches the second downward overspeed speed V2', the actuation mechanism triggers the rope clamping device to operate. When the elevator goes up, the rope pulley drives the main shaft to rotate in the second direction. The main shaft drives the speed detection mechanism to rotate. The rotation direction of the lower platform relative to the upper platform provides negative compensation to the lower platform. The negative compensation applies a downward force to the lower platform. The weight moves outward under the action of centrifugal force, which drives the lower platform to move upward. When the elevator speed reaches the first overspeed V1, the action mechanism triggers the electrical switch to operate. Among them, the downlink rated speed V0' < downlink first overspeed V1' < downlink second overspeed V2' < uplink rated speed V0 < uplink first overspeed V1.

2. The elevator bidirectional speed limiter according to claim 1, characterized in that, The transmission mechanism is a bevel gear, with the rotation axis of the rope pulley in the horizontal direction and the rotation axis of the main shaft in the vertical direction. The rotation axis of the rope pulley and the rotation axis of the main shaft are perpendicular to each other.

3. The elevator bidirectional speed limiter according to claim 1, characterized in that, The rotational speed of the pulley is the same as that of the main shaft.

4. The elevator bidirectional speed limiter according to claim 1, characterized in that, The first direction is clockwise, and the second direction is counterclockwise. When the spindle rotates clockwise, the lower platform rotates counterclockwise relative to the upper platform, providing positive compensation to the lower platform. When the spindle rotates counterclockwise, the lower platform rotates clockwise relative to the upper platform, providing negative compensation to the lower platform.

5. The elevator bidirectional speed limiter according to claim 1, characterized in that, The first direction is counterclockwise, and the second direction is clockwise. When the spindle rotates counterclockwise, the lower platform rotates clockwise relative to the upper platform, providing positive compensation to the lower platform. When the spindle rotates clockwise, the lower platform rotates counterclockwise relative to the upper platform, providing negative compensation to the lower platform.

6. The elevator bidirectional speed limiter according to claim 1, characterized in that, The actuation mechanism includes a bushing, a first rocker arm, a second rocker arm, a bracket, and an actuating rod; The lower platform and the bushing are connected by bearings to maintain consistent axial displacement and allow relative rotation; the bushing is hinged to the first rocker arm, and the two ends of the first rocker arm are respectively hinged to the second rocker arm and the actuating rod (53). The second rocker arm is hinged to the bracket, and the bracket is fixedly set on the housing of the transmission mechanism.

7. The elevator bidirectional speed limiter according to claim 1, characterized in that, The speed detection mechanism also includes three parallel connecting rods, which are connected to the upper platform and the lower platform respectively through ball joints; The connection points of the parallel connecting rods and the upper platform form a third equilateral triangle, and the connection points of the parallel connecting rods and the lower platform form a fourth equilateral triangle; when the main shaft is in a static state, the projections of the corresponding sides of the third and fourth equilateral triangles in the vertical direction are not parallel.

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