Overspeed protection switch suitable for multi-layer winding electric hoist

Abstract

The utility model relates to an overspeed protection switch suitable for a multilayer winding electric hoist, which comprises a box body, an elastic piece, a box cover, a rolling piece, a roller, a steel wire rope, a rotary encoder and a PLC (Programmable Logic Controller), the box cover is arranged on the box body through the elastic piece, the rolling piece is arranged in the box body, the roller is arranged in the box cover, and the steel wire rope is arranged in the box cover. The steel wire rope passes through the box body and the box cover and is located between the rolling piece and the roller, the rotary encoder is arranged outside the box body, the rotary encoder is connected with the rolling piece and used for measuring the moving speed of the steel wire rope, and the PLC is connected to the rotary encoder and used for controlling a loop of an electric hoist hoisting mechanism. Through mutual cooperation of the elastic piece, the rolling piece, the roller, the rotary encoder and the PLC, direct measurement of the moving speed of the steel wire rope is achieved, and therefore the overspeed protection requirement of a hoisting mechanism mainly comprising a multi-layer wound electric hoist is met.

Description

Technical Field

[0001] This utility model relates to an overspeed protection switch suitable for multi-layer wound electric hoists. Background Technology

[0002] Cranes, also known as "overhead cranes," are multi-action lifting machinery that vertically lifts and horizontally moves heavy objects within a certain range. According to the "Special Equipment Catalog," lifting machinery is divided into more than 20 varieties, among which cranes using electric hoists as lifting mechanisms are the most frequently used. According to the "TSG51-2023 Safety Technical Regulations for Lifting Machinery," all metallurgical cranes and lifting mechanisms that may cause danger must be equipped with overspeed protection devices to meet inspection requirements. Repurchasing lifting mechanisms with overspeed protection devices is not only uneconomical but also impractical. Therefore, in most cases, the inspection requirements are met by adding overspeed protection switches to the existing ones. Most existing overspeed protection switches calculate the speed of the lifting mechanism by measuring the drum rotation speed. However, this speed measurement method is not applicable to multi-layer wire rope winding drums. Therefore, there is an urgent need for a device that can meet the overspeed protection requirements of lifting mechanisms mainly based on multi-layer winding electric hoists. Utility Model Content

[0003] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0004] The technical problem this invention aims to solve is that most existing overspeed protection switches calculate the speed of the hoisting mechanism by measuring the drum rotation speed, but this speed measurement method is not applicable to multi-layer wire rope winding drums.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution: an overspeed protection switch suitable for multi-layer wound electric hoists, including a housing, an elastic element, a housing cover, a rolling element, a roller, a wire rope, a rotary encoder, and a PLC controller. The housing cover is set on the housing through the elastic element, the rolling element is set inside the housing, the roller is set inside the housing cover, the wire rope passes through the housing and the housing cover and is located between the rolling element and the roller, the rotary encoder is set outside the housing and connected to the rolling element for measuring the moving speed of the wire rope, and the PLC controller is connected to the rotary encoder for controlling the circuit of the electric hoist lifting mechanism.

[0006] As a preferred embodiment of the overspeed protection switch for multi-layer wound electric hoists described in this utility model, the elastic element includes four double-ended studs, four cylindrical helical springs, and four nuts. The four double-ended studs are respectively disposed at the four corners of the housing and the housing cover. The four cylindrical helical springs are respectively sleeved on the four double-ended studs. The four nuts are respectively disposed on the top of the four double-ended studs to realize a floating connection between the housing cover and the housing, so that the rollers and wheels can always be in contact with the wire rope.

[0007] As a preferred embodiment of the overspeed protection switch for multi-layer wound electric hoists described in this utility model, the roller includes a fixed shaft and a drum. The fixed shaft is horizontally fixed inside the housing cover, and the drum is rotatably mounted on the fixed shaft. Flanges are symmetrically provided at both ends of the drum to prevent the wire rope from sliding too much to the left and right, thereby reducing the measurement error of the rotary encoder on the wire rope's moving speed.

[0008] As a preferred embodiment of the overspeed protection switch for multi-layer winding electric hoists described in this utility model, the rolling element includes a rotating shaft, a bearing, and a roller. The rotating shaft is rotatably mounted in the housing via the bearing. The rotating shaft is parallel to the fixed shaft. The rotating shaft is fixedly connected to the motor shaft of the rotary encoder. The roller is fixedly mounted on the rotating shaft and is located between the flanges at both ends of the drum so that the wire rope can drive the roller to rotate together when it moves.

[0009] As a preferred embodiment of the overspeed protection switch for multi-layer winding electric hoists described in this utility model, a rubber flat gasket is provided between the housing and the cover, which can effectively reduce the impact generated by the housing and cover during operation, so as to prevent the rollers and wheels from excessively clamping the wire rope and causing deformation of the wire rope.

[0010] As a preferred embodiment of the overspeed protection switch for multi-layer wound electric hoists described in this utility model, the height of the flange is not less than half the diameter of the wire rope, so as to prevent the wire rope from slipping off the drum during movement.

[0011] As a preferred embodiment of the overspeed protection switch for multi-layer winding electric hoists described in this utility model, the bottom of the housing is provided with a balancing component, which includes a first traction rope and a counterweight. The counterweight is hung on the bottom of the housing by the first traction rope to prevent the wire rope from being pulled backward.

[0012] As a preferred embodiment of the overspeed protection switch for multi-layer wound electric hoists described in this utility model, the top of the box cover is provided with a connector, the connector including a second traction rope and a screw, the screw is set on the top of the box cover through the second traction rope, and the screw is fixedly connected to the rope guide of the electric hoist in order to fix the entire overspeed protection switch.

[0013] Beneficial effects:

[0014] 1. By cooperating with each other, elastic components, rolling components, rollers, rotary encoders and PLC controllers, the direct measurement of the wire rope movement speed can be achieved, thereby meeting the overspeed protection requirements of hoisting mechanisms mainly based on multi-layer wound electric hoists.

[0015] 2. This device has a simple overall structure and is easy to install, allowing for installation without disassembling the existing electric hoist;

[0016] 3. When the rotary encoder detects that the moving speed of the wire rope exceeds the specified value, the power supply of the hoisting mechanism can be effectively cut off through the PLC controller to ensure the safety of equipment and personnel, thereby meeting the overspeed protection requirements of hoisting mechanisms mainly based on multi-layer winding electric hoists. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0018] Figure 1 This is a schematic diagram of the overall structure of an overspeed protection switch suitable for multi-layer wound electric hoists.

[0019] Figure 2 For overspeed protection switches suitable for multi-layer wound electric hoists Figure 1 Enlarged view of point A in the middle.

[0020] In the diagram: 1. Box cover; 2. Box body; 3. Steel wire rope; 4. Fixed shaft; 5. Roller; 6. Rotating shaft; 7. Roller; 8. Bearing; 9. Rotary encoder; 10. Double-ended stud; 11. Nut; 12. Cylindrical helical spring; 13. Rubber flat washer; 14. PLC controller; 15. Flange; 16. First traction rope; 17. Counterweight; 18. Second traction rope; 19. Screw. Detailed Implementation

[0021] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0022] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0023] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0024] Example

[0025] Reference Figure 1 and Figure 2 This embodiment provides an overspeed protection switch suitable for multi-layer wound electric hoists. It mainly determines whether the lifting mechanism is overspeeding by measuring the moving speed of the electric hoist wire rope 3. Specifically, it includes a housing 2, an elastic element, a housing cover 1, a rolling element, a roller, a wire rope 3, a rotary encoder 9, and a PLC controller 14. The housing cover 1 is set on the housing 2 through the elastic element. The rolling element is set inside the housing 2, and the roller is set inside the housing cover 1. The wire rope 3 passes through the housing 2 and the housing cover 1 and is located between the rolling element and the roller. The rotary encoder 9 is set outside the housing 2 and is connected to the rolling element to measure the moving speed of the wire rope 3. The PLC controller 14 is connected to the rotary encoder 9 to control the circuit of the electric hoist lifting mechanism.

[0026] The housing 2 serves as the installation base for the entire overspeed protection switch. Rolling elements are installed inside the housing 2. A cover 1 is floatingly connected to the housing 2 via elastic elements. Rollers are installed inside the cover 1. The wire rope 3 of the multi-layer wound electric hoist passes through the cover 1 and the housing 2, meaning the wire rope 3 runs through both. The wire rope 3 must be positioned between the rolling elements and the rollers so that they are always in contact with the wire rope 3. A rotary encoder 9 is fixedly installed outside the housing 2 and connected to the rolling elements to measure the moving speed of the wire rope 3. A PLC controller 14 is connected to the rotary encoder 9 via a signal line. The PLC controller 14 is connected to the hoist lifting mechanism circuit via an intermediate relay. When the rotary encoder 9 detects that the moving speed of the wire rope 3 exceeds a specified value, the PLC controller 14 can effectively cut off the power supply to the lifting mechanism to ensure the safety of equipment and personnel, thus meeting the overspeed protection requirements of the lifting mechanism, which is mainly based on a multi-layer wound electric hoist.

[0027] Specifically, the elastic components include four double-ended studs 10, four cylindrical helical springs 12, and four nuts 11. The four double-ended studs 10 are respectively located at the four corners of the housing 2 and the housing cover 1. The four cylindrical helical springs 12 are respectively sleeved on the four double-ended studs 10. The four nuts 11 are respectively located on the top of the four double-ended studs 10.

[0028] In this embodiment, the elastic element mainly consists of four double-ended studs 10, four cylindrical helical springs 12, and four nuts 11. Four double-ended studs 10 are fixedly installed at the four corners of the housing 2. Four mounting holes corresponding to the four double-ended studs 10 are provided at the four corners of the housing cover 1. During installation, the four double-ended studs 10 pass through the four mounting holes. Then, four cylindrical helical springs 12 are fitted onto the four double-ended studs 10. Finally, four nuts 11 are fitted onto the tops of the four double-ended studs 10 to fix the cylindrical helical springs 12, thus achieving a floating connection between the housing cover 1 and the housing 2. During use, the pressure exerted by the cylindrical helical springs 12 on the housing cover 1 can be adjusted by turning the nuts 11, ensuring that the roller 5 inside the housing cover 1 and the roller 7 inside the housing 2 remain in contact with the wire rope 3. It should be noted that this embodiment uses cylindrical helical springs 12 to provide a certain preload, allowing for adjustment of the spring's elasticity.

[0029] Specifically, the roller includes a fixed shaft 4 and a roller 5. The fixed shaft 4 is horizontally fixed inside the box cover 1, and the roller 5 is rotatably mounted on the fixed shaft 4. Flanges 15 are symmetrically arranged at both ends of the roller 5.

[0030] In this embodiment, the roller is mainly composed of a fixed shaft 4 and a roller 5. The fixed shaft 4 is horizontally fixedly installed inside the cover 1, and the roller 5 is fitted on the fixed shaft 4 so that the roller 5 and the fixed shaft 4 are rotatably connected to avoid the roller 5 affecting the normal movement of the wire rope 3 during operation. Flanges 15 are symmetrically arranged at the left and right ends of the roller 5 to prevent the wire rope 3 from sliding too much to the left and right during movement, thereby reducing the measurement error of the rotary encoder 9 on the moving speed of the wire rope 3.

[0031] Specifically, the rolling element includes a rotating shaft 6, a bearing 8, and a roller 7. The rotating shaft 6 is rotatably mounted inside the housing 2 via the bearing 8. The rotating shaft 6 is parallel to the fixed shaft 4. The rotating shaft 6 is fixedly connected to the motor shaft of the rotary encoder 9. The roller 7 is fixedly mounted on the rotating shaft 6 and is located between the flanges 15 at both ends of the roller 5.

[0032] In this embodiment, the rolling element mainly consists of a rotating shaft 6, a bearing 8, and a roller 7. The rotating shaft 6 is rotatably mounted inside the housing 2 via the bearing 8, and the rotating shaft 6 is parallel to the fixed shaft 4. The right end of the rotating shaft 6 is fixedly connected to the motor shaft of the rotary encoder 9 so that the rotary encoder 9 can measure the rotational speed of the rotating shaft 6. The roller 7 is fixedly mounted on the rotating shaft 6, and the roller 7 is positioned between the flanges 15 at both ends of the drum 5 so that the roller 7 can maintain better contact with the wire rope 3, so that the wire rope 3 can drive the roller 7 to rotate together when it moves. The roller 7 drives the rotating shaft 6 to rotate, and the rotary encoder 9 measures the rotational speed of the rotating shaft 6, thereby realizing the measurement of the moving speed of the wire rope 3.

[0033] Furthermore, a rubber flat gasket 13 is provided between the box body 2 and the box cover 1.

[0034] In this embodiment, a rubber flat gasket 13 is installed at the connection between the box body 2 and the box cover 1. The double-headed stud 10 passes through the rubber flat gasket 13. The rubber flat gasket 13 can effectively reduce the impact generated by the box body 2 and the box cover 1 during operation, so as to prevent the roller 5 and the roller 7 from excessively clamping the wire rope 3 and causing the wire rope 3 to deform.

[0035] Furthermore, the height of flange 15 is not less than half the diameter of wire rope 3.

[0036] In this embodiment, the height of the flange 15 is designed to be no less than half the diameter of the wire rope 3 to prevent the wire rope 3 from slipping out of the drum 5 during movement, thereby improving the measurement accuracy of the moving speed of the wire rope 3.

[0037] Furthermore, a balancing component is provided at the bottom of the box 2. The balancing component includes a first traction rope 16 and a counterweight 17. The counterweight 17 is hung at the bottom of the box 2 by the first traction rope 16.

[0038] In this embodiment, a balancing component is installed at the bottom of the housing 2 to prevent the wire rope 3 from being pulled backward. Specifically, the balancing component mainly consists of a first traction rope 16 and a counterweight 17. One end of the first traction rope 16 is fixedly connected to the bottom of the housing 2, and the other end of the first traction rope 16 is fixedly connected to the counterweight 17, so that the entire device is subjected to a downward force to prevent the wire rope 3 from being pulled backward and causing the roller 7 to reverse.

[0039] Furthermore, a connector is provided on the top of the cover 1. The connector includes a second traction rope 18 and a screw 19. The screw 19 is set on the top of the cover 1 through the second traction rope 18 and is fixedly connected to the rope guide of the electric hoist.

[0040] In this embodiment, a connector is provided on the top of the cover 1 to fix the entire overspeed protection switch. Specifically, the connector is mainly composed of a second traction rope 18 and a screw 19. One end of the second traction rope 18 is fixedly connected to the top of the cover 1, and the other end of the second traction rope 18 is fixedly connected to the screw 19. The screw 19 is fixedly installed on the rope guide of the electric hoist, thereby fixing the entire overspeed protection switch.

[0041] When the lifting mechanism of the electric hoist with multi-layer wire rope 3 is working, the wire rope 3 moves. Since the drum 5 and roller 7 are always in contact with the wire rope 3, the movement of the wire rope 3 will drive the drum 5 and roller 7 to rotate together. The roller 7 drives the rotating shaft 6 to rotate, and the rotating shaft 6 drives the motor shaft of the rotary encoder 9 to rotate. The rotary encoder 9 measures the rotation speed of the rotating shaft 6 to measure the moving speed of the wire rope 3. The rotary encoder 9 measures the moving speed of the wire rope 3 and transmits its signal to the PLC controller 14. The PLC controller 14 determines whether the moving speed of the wire rope exceeds the specified value. If it exceeds the specified value, the PLC controller 14 outputs a signal to the intermediate relay, which disconnects the lifting mechanism circuit of the electric hoist, effectively cutting off the power supply of the lifting mechanism to ensure the safety of the equipment and personnel, thereby meeting the overspeed protection requirements of the lifting mechanism mainly based on multi-layer wound electric hoists.

[0042] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An overspeed protection switch for a multi-winding electric hoist, characterized in that: The device includes a housing (2), an elastic element, a cover (1), a rolling element, a roller, a wire rope (3), a rotary encoder (9), and a PLC controller (14). The cover (1) is mounted on the housing (2) via the elastic element. The rolling element is located inside the housing (2). The roller is located inside the cover (1). The wire rope (3) passes through the housing (2) and the cover (1) and is located between the rolling element and the roller. The rotary encoder (9) is located outside the housing (2) and is connected to the rolling element. It is used to measure the moving speed of the wire rope. The PLC controller (14) is connected to the rotary encoder (9) and is used to control the circuit of the electric hoist lifting mechanism.

2. The overspeed protection switch suitable for use in a multi-layer winding electro-hoist according to claim 1, characterized in that: The elastic element includes four double-ended studs (10), four cylindrical helical springs (12), and four nuts (11). The four double-ended studs (10) are respectively located at the four corners of the housing (2) and the cover (1). The four cylindrical helical springs (12) are respectively sleeved on the four double-ended studs (10). The four nuts (11) are respectively located on the top of the four double-ended studs (10).

3. The overspeed protection switch suitable for use in a multi-layer winding electro-hoist according to claim 2, characterized in that: The roller includes a fixed shaft (4) and a roller (5). The fixed shaft (4) is horizontally fixed inside the box cover (1), and the roller (5) is rotatably mounted on the fixed shaft (4). Flanges (15) are symmetrically arranged at both ends of the roller (5).

4. The overspeed protection switch for a multi-layer winding electro-hoist according to claim 3, characterized in that: The rolling element includes a rotating shaft (6), a bearing (8), and a roller (7). The rotating shaft (6) is rotatably mounted inside the housing (2) via the bearing (8). The rotating shaft (6) is parallel to the fixed shaft (4). The rotating shaft (6) is fixedly connected to the motor shaft of the rotary encoder (9). The roller (7) is fixedly mounted on the rotating shaft (6) and is located between the flanges (15) at both ends of the drum (5).

5. The overspeed protection switch suitable for use in a multi-layer winding electro-hoist according to claim 2, characterized in that: A rubber gasket (13) is provided between the box body (2) and the box cover (1).

6. The overspeed protection switch suitable for use in a multi-layer winding electro-hoist according to claim 3, characterized in that: The height of the flange (15) is not less than half the diameter of the wire rope (3).

7. The overspeed protection switch suitable for use in a multi-layer winding electro-hoist according to claim 1, characterized in that: The bottom of the box (2) is provided with a balancing component, which includes a first traction rope (16) and a counterweight (17). The counterweight (17) is hung on the bottom of the box (2) by the first traction rope (16).

8. The overspeed protection switch for multi-layer wound electric hoists as described in claim 1, characterized in that: The top of the box cover (1) is provided with a connector, which includes a second traction rope (18) and a screw (19). The screw (19) is set on the top of the box cover (1) through the second traction rope (18) and is fixedly connected to the rope guide of the electric hoist.

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