Mechanical limiting device of electric hoist
By designing an adjustment structure within the frame housing, the limit baffle is allowed to disengage from the nut to adjust the electric hoist's stroke, solving the problems of complex and non-adjustable limit structure adjustment in existing electric hoists, and achieving improvements in flexibility and efficiency.
Patent Information
- Application Number
- CN202511984948.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-02-17
AI Technical Summary
The existing mechanical travel limit structure of electric hoists cannot be precisely adjusted according to different working environments, resulting in limit protection failure or complicated operation, increasing the risk of equipment damage and personal injury, and the adjustment efficiency is low.
A mechanical limiting device was designed, comprising a frame housing, a screw shaft, an upper limit nut, a lower limit nut, a limit baffle, and an adjustment structure. The adjustment structure allows the limit baffle to temporarily disengage from the nuts, and the stroke is adjusted by changing the distance between the nuts, thus simplifying the adjustment process.
This technology enables flexible adjustment of the electric hoist's stroke according to different working environments, improving the equipment's practicality and operational efficiency, reducing adjustment time, and lowering the risk of equipment damage and personal injury.
Smart Images
Figure CN121536840A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the technical field of electric hoists, in particular to a mechanical limiting device for an electric hoist. BACKGROUND
[0002] As a common light and small hoisting equipment, the safe and reliable operation of an electric hoist is very important. In order to prevent over-winding or lowering when the lifting appliance runs to the upper and lower limit positions, a limiting structure is usually installed to cut off the power supply and realize shutdown protection when triggered.
[0003] The mechanical stroke limiting structure commonly used in existing electric hoists is generally fixed and cannot be adjusted. It cannot be accurately set according to different operating environments, and in some working conditions, the limiting protection may fail or act in time, thereby increasing the risk of equipment damage and personnel injury, and the practicability and flexibility of the equipment are insufficient. The mechanical stroke limiting structure used in part of the electric hoists is adjustable, which needs to disassemble the limiting plate, then adjust the stroke by changing the position of the limiting nut, and then install and reset the limiting plate after the adjustment is completed. This adjustment method is relatively cumbersome, complex to operate, time-consuming and low in efficiency. SUMMARY
[0004] To solve the above technical problems, the application provides a mechanical limiting device for an electric hoist, and the technical scheme adopted by the application is: A mechanical limiting device for an electric hoist, comprising: a frame shell; a screw shaft, which is rotationally connected with the frame shell; an upper limiting nut, which is connected with the screw shaft in a threaded engagement manner; a lower limiting nut, which is connected with the screw shaft in a threaded engagement manner; an upper stop point limiting switch, which is arranged in the frame shell and located on one side of the upper limiting nut; a lower stop point limiting switch, which is arranged in the frame shell and located on one side of the lower limiting nut; a limiting baffle, which is arranged in the frame shell, and the upper limiting nut and the lower limiting nut are both slidably connected with the limiting baffle; an adjusting structure, which is fixedly arranged in the frame shell and fixedly connected with the limiting baffle.
[0005] Further, the outer circumferential surface of the upper limiting nut and the lower limiting nut is provided with a plurality of evenly distributed clamping grooves, and the upper limiting nut and the lower limiting nut are slidably connected with the limiting baffle through the clamping grooves.
[0006] Further, the adjusting structure comprises a T-shaped connecting plate and a connecting block, the T-shaped connecting plate is connected with the connecting block, the connecting block is fixedly connected with the frame shell, a first groove is formed in the lower end surface of the connecting block, second grooves are formed in the two inner side walls of the first groove, the T-shaped connecting plate is connected with the second grooves, an upper limiting groove is formed in the upper wall of the second groove, and a lower limiting groove is formed in the lower wall of the second groove; an upper protrusion corresponding to the upper limiting groove is fixedly arranged on the upper end surface of the horizontal section of the T-shaped connecting plate, and a lower protrusion corresponding to the lower limiting groove is fixedly arranged on the lower end surface of the horizontal section of the T-shaped connecting plate.
[0007] Further, side limiting grooves are formed in the inner side walls of the second grooves; third grooves are formed in the two side end surfaces of the horizontal section of the T-shaped connecting plate, springs are fixedly arranged in the inner side walls of the third grooves, and limiting spherical bodies corresponding to the third grooves are fixedly connected to the other ends of the springs.
[0008] Further, an auxiliary plate is fixedly arranged on the vertical end surface of the T-shaped connecting plate.
[0009] Further, the limiting baffle comprises an upper supporting plate and a lower clamping plate, the lower clamping plate is fixedly connected with the supporting plate, the upper end surface of the supporting plate is fixedly connected with the lower end surface of the T-shaped connecting plate, the lower clamping plate is connected with the clamping groove in a clamping manner, and scale lines are arranged on the outer side end surface of the lower clamping plate.
[0010] Further, upper limit switches and lower limit switches are arranged in the frame shell, the upper limit switches are arranged on one side of the upper limiting nut, and the lower limit switches are arranged on one side of the lower limiting nut.
[0011] Further, a driving gear is fixedly connected to one end of the screw shaft, and the driving gear is fixedly connected with an external motor.
[0012] The beneficial effects of the present application are as follows: when the upper limiting nut touches the upper stop point limiting switch, the upward stroke limiting of the electric hoist is realized; when the lower limiting nut touches the lower stop point limiting switch, the downward stroke limiting of the electric hoist is realized. By arranging the limiting baffle and the adjusting structure, the limiting baffle can temporarily separate from the upper limiting nut and the lower limiting nut through the adjusting structure, the circumferential limiting of the upper limiting nut and the lower limiting nut by the contact limiting baffle, and then the running stroke of the electric hoist is adjusted by changing the distance between the upper limiting nut and the lower limiting nut, so as to meet the requirements of different working environments on the stroke of the electric hoist, and the practicability and flexibility of the equipment are increased.
[0013] When the travel limit needs to be adjusted, first use the T-shaped connecting plate to move the limit baffle out of the slots of the upper and lower limit nuts. The lower protrusion of the T-shaped connecting plate disengages from the lower limit groove of the connecting block. The T-shaped connecting plate moves along the inner side wall of the second groove to the top wall of the second groove until the upper protrusion of the T-shaped connecting plate engages with the upper limit groove of the connecting block. Then, adjust the distance between the upper and lower limit nuts as needed to change the travel of the electric hoist. This operation is simple and quick, eliminating the need for repeated disassembly and installation of the limit baffle, reducing adjustment time and improving work efficiency. Attached Figure Description
[0014] Figure 1 This is a front view of the present invention.
[0015] Figure 2 This is the present invention. Figure 1 A sectional view.
[0016] Figure 3 This is the present invention. Figure 2 A sectional view.
[0017] Figure 4 This is the present invention. Figure 2 A state diagram.
[0018] Figure 5 This is the present invention. Figure 2 Enlarged view at point A.
[0019] Figure 6 This is the present invention. Figure 4 Enlarged view at point B.
[0020] In the picture: 1. Frame housing; 2. Screw shaft; 3. Upper limit nut; 4. Lower limit nut; 5. Upper stop limit switch; 6. Lower stop limit switch; 7. Limit baffle; 71. Upper support plate; 72. Lower clamping plate; 8. Adjustment structure; 81. T-shaped connecting plate; 82. Connecting block; 9. Slot; 10. First groove; 11. Second groove; 12. Upper limit groove; 13. Lower limit groove; 14. Upper protrusion; 15. Lower protrusion; 16. Side limit groove; 17. Third groove; 18. Spring; 19. Limiting ball; 20. Auxiliary plate; 21. Upper limit switch; 22. Lower limit switch; 23. Drive gear. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will now be described in further detail with reference to the accompanying drawings and the following embodiments, so that the public can better understand the implementation method of this invention. The specific implementation scheme of this invention is as follows: like Figures 1-6As shown, an electric hoist mechanical limiting device includes a frame housing 1. A screw shaft 2 is rotatably disposed within the frame housing 1, and the screw shaft 2 is threadedly connected to an upper limit nut 3 and a limiting nut. An upper stop limit switch 5 is disposed on one side of the upper limit nut 3, and the upper stop limit switch 5 is disposed within the frame housing 1. A lower stop limit switch 6 is disposed on one side of the lower limit nut 4, and the lower stop limit switch 6 is disposed within the frame housing 1. A limit baffle 7 is disposed within the frame housing 1, and both the upper limit nut 3 and the lower limit nut 4 are slidably connected to the limit baffle 7. An adjusting structure 8 is fixedly connected to the limit baffle 7, and the adjusting structure 8 is fixedly disposed within the frame housing 1. When the upper limit nut 3 touches the upper stop limit switch 5, the upper stroke of the electric hoist is limited; when the lower limit nut 4 touches the lower stop limit switch 6, the lower stroke of the electric hoist is limited. By setting a limit baffle 7 and an adjustment structure 8, the limit baffle 7 can temporarily disengage from the upper limit nut 3 and the lower limit nut 4 through the adjustment structure 8. The limit baffle 7 then contacts the upper limit nut 3 and the lower limit nut 4, thus limiting their circumferential movement. This allows the electric hoist's travel to be adjusted by changing the distance between the upper limit nut 3 and the lower limit nut 4, thereby meeting the travel requirements of different working environments and increasing the practicality and flexibility of the equipment.
[0022] It should be noted that the outer circumferential surfaces of the upper limit nut 3 and the lower limit nut 4 are provided with several evenly distributed slots 9. The upper limit nut 3 and the lower limit nut 4 are slidably connected to the limiting baffle 7 through the slots 9. The limiting baffle 7 is engaged in the slots 9 of the upper limit nut 3 and the lower limit nut 4 to circumferentially limit the upper limit nut 3 and the lower limit nut 4, ensuring that when the screw shaft 2 rotates, it drives the upper limit nut 3 and the lower limit nut 4 to make axial movements along the screw shaft 2 close to the upper dead point limit switch 5 or the lower dead point limit switch 6.
[0023] It should be noted that the adjustment structure 8 includes a T-shaped connecting plate 81 and a connecting block 82. The T-shaped connecting plate 81 is connected to the connecting block 82, and the connecting block 82 is fixedly connected to the frame housing 1. A first groove 10 is formed on the lower end face of the connecting block 82. A second groove 11 is formed on the two inner side walls of the first groove 10. The T-shaped connecting plate 81 is slidably connected to the second groove 11. An upper limit groove 12 is formed on the upper wall of the second groove 11, and a lower limit groove 13 is formed on the lower wall of the second groove 11. An upper protrusion 14 corresponding to the upper limit groove 12 is fixedly provided on the upper end face of the horizontal section of the T-shaped connecting plate 81, and a lower protrusion 15 corresponding to the lower limit groove 13 is fixedly provided on the lower end face of the horizontal section of the T-shaped connecting plate 81.
[0024] Furthermore, a side limiting groove 16 is provided on the inner side wall of the second groove 11; a third groove 17 is provided on both ends of the horizontal section of the T-shaped connecting plate 81; a spring 18 is fixedly provided on the inner side wall of the third groove 17; and a limiting ball 19 corresponding to the third groove 17 is fixedly connected to the other end of the spring 18; the limiting ball 19 is spaced within the third groove 17.
[0025] Specifically, when it is necessary to change the travel of the electric hoist by adjusting the distance between the upper limit nut 3 and the lower limit nut 4: Move the T-shaped connecting plate 81 away from the limiting nut (towards the upper wall of the second groove 11). The lower protrusion 15 of the T-shaped connecting plate 81 gradually disengages from the lower limiting groove 13. The T-shaped limiting plate moves along the inner wall of the second groove 11 towards the upper wall of the second groove 11. The movement of the T-shaped connecting plate 81 will drive the limiting baffle 7, the lower protrusion 15, the upper protrusion 14, the limiting ball 19, and the spring 18 to move together until the upper protrusion 14 is engaged in the upper limiting groove 12. At this point, the limiting baffle 7 has completely disengaged from the upper limiting nut 3 and the lower limiting nut 14. The retaining nut 4 has a slot 9; during this process, before the retaining ball 19 reaches the side retaining groove 16, the retaining ball 19 exerts pressure on the spring 18 under the compression of the inner wall of the second groove 11, and the retaining ball 19 is completely in the third groove 17. When the retaining ball 19 moves to the side retaining groove 16 with the T-shaped connecting plate 81, the inner wall of the second groove 11 no longer provides pressure to the retaining ball 19, and the spring 18 releases its elastic force, so that the retaining ball 19 partially enters the side retaining groove 16, thereby limiting the T-shaped connecting plate 81.
[0026] After adjusting the distance between the upper limit nut 3 and the lower limit nut 4, move the T-shaped connecting plate 81 towards the limit nuts (towards the lower wall of the second groove 11). The upper protrusion 14 of the T-shaped connecting plate 81 gradually disengages from the upper limit groove 12. The T-shaped limiting plate moves along the inner wall of the second groove 11 towards the lower wall of the second groove 11. The movement of the T-shaped connecting plate 81 will drive the limiting baffle 7, the lower protrusion 15, the upper protrusion 14, the limiting ball 19, and the spring. Spring 18 moves together until lower protrusion 15 is engaged in lower limit groove 13, and limit baffle 7 is engaged in the groove 9 of upper limit nut 3 and lower limit nut 4. During this process, limit ball 19 will gradually disengage from side limit groove 16. When limit ball 19 is completely disengaged from side limit groove 16, the inner wall of second groove 11 provides a squeezing force to limit ball 19, so that limit ball 19 is completely in third groove 17. At this time, spring 18 is in a compressed state.
[0027] Furthermore, an auxiliary plate 20 is fixedly provided on the side of the vertical end of the T-shaped connecting plate 81; this structure facilitates the movement of the T-shaped connecting plate 81.
[0028] It should be noted that the limiting baffle 7 includes an upper support plate 71 and a lower clamping plate 72. The lower clamping plate 72 is fixedly connected to the support plate, and the upper end face of the support plate is fixedly connected to the lower end face of the T-shaped connecting plate 81. The lower clamping plate 72 is engaged with the clamping groove 9. The outer end face of the lower clamping plate 72 is provided with a scale mark (not shown in the attached figure). This scale mark is a common scale mark. The setting of the scale mark makes it convenient for the operator to adjust the distance between the upper limit nut 3 and the lower limit nut 4 without the need for additional tools to measure and then adjust the distance between the two, further improving the working efficiency of adjusting the limit nuts.
[0029] It should be noted that the frame housing 1 is equipped with an upper limit switch 21 and a lower limit switch 22. The upper limit switch 21 is located on the side of the upper limit nut 3, and the lower limit switch 22 is located on the side of the lower limit nut 4. This structure is mainly designed to provide dual protection for the electric hoist. When the upper stop limit switch 5 or the lower stop limit switch 6 malfunctions, the upper limit nut 3 touches the upper limit switch 21 or the lower limit nut 4 touches the lower limit switch 22, thereby limiting the upper or lower travel of the electric hoist.
[0030] It should be noted that a drive gear 23 is fixedly connected to one end of the screw shaft 2, and the drive gear 23 is fixedly connected to an external motor; the external motor is located inside the electric hoist body.
[0031] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "left," "right," "front," "rear," "lower left," "upper right," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Although the invention has been described according to a limited number of embodiments, those skilled in the art should understand from the above description that other embodiments are conceived within the scope of the invention described herein.
Claims
1. A mechanical limit device for an electric hoist, characterized in that, include: Frame shell (1); Screw shaft (2), which is rotatably connected to the frame housing (1); The upper limit nut (3) is connected to the screw shaft (2) by a threaded engagement. The lower limit nut (4) is connected to the screw shaft (2) by a threaded engagement. The upper stop limit switch (5) is installed inside the frame housing (1) and is located on one side of the upper limit nut (3). The lower stop limit switch (6) is installed inside the frame housing (1) and is located on one side of the lower limit nut (4). Limiting baffle (7), the limiting baffle (7) is set inside the frame housing (1), the upper limit nut (3) and the lower limit nut (4) are slidably connected to the limiting baffle (7); Adjustment structure (8) is fixedly installed inside the frame housing (1) and is fixedly connected to the limiting baffle (7).
2. The electric hoist mechanical limit device according to claim 1, characterized in that: The outer circumferential surfaces of the upper limit nut (3) and the lower limit nut (4) are provided with several evenly distributed slots (9), and the upper limit nut (3) and the lower limit nut (4) are slidably connected to the limiting baffle (7) through the slots (9).
3. The electric hoist mechanical limit device according to claim 1, characterized in that: The adjustment structure (8) includes a T-shaped connecting plate (81) and a connecting block (82). The T-shaped connecting plate (81) is connected to the connecting block (82). The connecting block (82) is fixedly connected to the frame shell (1). A first groove (10) is opened on the lower end face of the connecting block (82). A second groove (11) is opened on the two inner side walls of the first groove (10). The T-shaped connecting plate (81) is connected to the second groove (11). An upper limit groove (12) is opened on the upper wall of the second groove (11). A lower limit groove (13) is opened on the lower wall of the second groove (11). The upper end face of the horizontal section of the T-shaped connecting plate (81) is fixedly provided with an upper protrusion (14) corresponding to the upper limit groove (12), and the lower end face of the horizontal section of the T-shaped connecting plate (81) is fixedly provided with a lower protrusion (15) corresponding to the lower limit groove (13).
4. The electric hoist mechanical limit device according to claim 3, characterized in that: The inner wall of the second groove (11) is provided with a side limiting groove (16); the two ends of the horizontal section of the T-shaped connecting plate (81) are provided with a third groove (17), the inner wall of the third groove (17) is fixedly provided with a spring (18), and the other end of the spring (18) is fixedly connected with a limiting ball (19) corresponding to the third groove (17).
5. The electric hoist mechanical limit device according to claim 3, characterized in that: An auxiliary plate (20) is fixedly installed on the side of the vertical end of the T-shaped connecting plate (81).
6. The electric hoist mechanical limit device according to claim 1, characterized in that: The limiting baffle (7) includes an upper support plate (71) and a lower clamping plate (72). The lower clamping plate (72) is fixedly connected to the support plate. The upper surface of the support plate is fixedly connected to the lower surface of the T-shaped connecting plate (81). The lower clamping plate (72) is clamped to the slot (9). The outer end surface of the lower clamping plate (72) is provided with scale markings.
7. The electric hoist mechanical limit device according to claim 1, characterized in that: The frame housing (1) is provided with an upper limit switch (21) and a lower limit switch (22). The upper limit switch (21) is located on the side of the upper limit nut (3), and the lower limit switch (22) is located on the side of the lower limit nut (4).
8. The electric hoist mechanical limit device according to claim 1, characterized in that: One end of the screw shaft (2) is fixedly connected to a drive gear (23), which is fixedly connected to an external motor.