Anti-overload electric chain hoist

Abstract

The utility model discloses an anti-overload electric chain hoist, and relates to the field of mechanical transmission devices. The electric hoist comprises a transmission structure provided with an overload protection clutch, the clutch comprises a clutch shaft, a first-stage driven gear, two clutch seats and friction plates, the first-stage driven gear is clamped between the clutch seats, and the two friction plates are fixedly sintered on the end face of the first-stage driven gear. The friction plate is made of a copper-based powder material and forms an integrated structure with the gear through a sintering process, so that the friction coefficient stability and the high temperature resistance are improved, the service life is prolonged, and the maintenance frequency is reduced. Fractures are formed in the surfaces of the friction plates and used for guiding oil, dissipating heat and removing scraps. The structure can achieve stable torque transmission under motor driving and reliable slipping during overload, has the advantages of being compact in structure, stable in torque, high in abrasion resistance and the like, and is suitable for an electric chain hoist system under high-frequency lifting and severe working condition environments.

Description

TECHNICAL FIELD

[0001] The utility model belongs to mechanical transmission device technical field, especially relate to a ring chain electric hoist with anti overload function. BACKGROUND

[0002] The ring chain electric hoist is a kind of lifting equipment widely used in industrial field, and is commonly seen in factory, warehouse, construction site and other places, and is used for carrying and lifting heavy objects. Its working principle is to drive chain movement by motor, to realize the vertical lifting or horizontal movement of load. In the transmission system of ring chain electric hoist, the clutch as a key component bears important function: on the one hand, it is responsible for transmitting the power of motor to chain drive mechanism through torque, to ensure the stable lifting of load, on the other hand, it limits the torque output through the slip mechanism when the system is overloaded, to prevent the damage of equipment due to overload, to protect the safety of transmission system and lifting chain.

[0003] In the traditional design of ring chain electric hoist clutch, the core structure of clutch usually includes the following parts: gear, friction plate, disc spring and adjusting nut. Specifically, the gear is provided with a piece of resin friction plate with thickness of 1mm at each end, and these friction plates transmit torque by contacting with gear and other transmission components. In order to ensure the proper compression force between friction plate and gear, disc spring (i.e. disc spring) is used to apply pressure in the design. The disc spring can provide stable compression force in limited space due to its high elasticity, high load capacity and compact structure. In addition, by adjusting the tightening degree of adjusting nut, the compression amount of disc spring can be changed, so as to adjust the pressure between friction plates, to realize the slip of clutch within the preset torque range. This slip mechanism is the core of overload protection of clutch, when the load exceeds the design torque, the friction plate will slip between the gears, to avoid the transmission of excessive torque to chain or other components, to protect the whole system.

[0004] However, this traditional design has certain limitations in actual use. As the main friction material, resin friction plate has certain wear resistance and cost advantage, but it is easy to wear under long-term high-load operation. The wear of friction plate will cause the change of surface roughness or material loss, to reduce the friction coefficient, to make the slip torque value of clutch deviate from the design range, to affect the stability of overload protection. In extreme cases, the seriously worn friction plate can cause the clutch to fail to slip normally, to cause the overload of transmission system, chain breakage or other safety accidents.

[0005] In summary, although the traditional design of ring chain electric hoist clutch can meet the basic torque transmission and overload protection requirements in function, its structure relying on resin friction plate exposes the problems of unstable slip torque and high maintenance requirement in long-term use. UTILITY MODEL CONTENT

[0006] The utility model discloses to solve the technical problems of the existing anti-overload ring chain electric hoist, provide a kind of clutch's anti-overload ring chain electric hoist with structure stable, friction plate high temperature resistance, reduce maintenance requirement and long service life.

[0007] To achieve the above object, the technical scheme of the utility model is as follows:

[0008] An anti-overload ring chain electric hoist comprises a clutch with overload protection for connecting a motor to a sprocket. The clutch comprises a clutch shaft, a primary driven gear sleeved on the clutch shaft, and two clutch seats and friction plates. The primary driven gear is clamped between the two clutch seats, and the two friction plates are respectively arranged between the primary driven gear two end faces and the clutch seats adjacent thereto. The two friction plates are fixedly arranged on the two end faces of the primary driven gear.

[0009] By fixing the friction plates on the two end faces of the primary driven gear, slipping between the friction plates and the primary driven gear is prevented, the friction coefficient between the friction plates and the clutch seats is relatively stable, and the durability of the friction plates is improved.

[0010] Further, the friction plates are fixed on the two end faces of the primary driven gear by copper-based powder sintering.

[0011] The friction plates are sintered on the primary driven gear to form an integral structure, further improving the stability and durability of the slipping torque, and the sintered friction plates have high temperature resistance and long service life characteristics.

[0012] Preferably, the friction plates on the two end faces of the primary driven gear are annular, and a plurality of discontinuous friction plate discontinuities are arranged on the annular friction plates.

[0013] By arranging discontinuities on the annular friction plates, oil flow is guided for lubricating the surface, dissipating heat and removing wear debris.

[0014] Further, the clutch further comprises a check ring, a first bearing, a disc spring, a secondary driving gear, a washer, a second bearing and a locking nut arranged in sequence on the clutch shaft. The two clutch seats are arranged between the disc spring and the secondary driving gear.

[0015] Further, the anti-overload ring chain electric hoist further comprises a shell, a ring chain arranged on a chain wheel, a motor shaft arranged in the shell, a first driving gear arranged on the motor shaft, a third transmission shaft, a second driven gear and a third driving gear arranged on the third transmission shaft, and a chain wheel shaft and a third driven gear arranged on the chain wheel shaft; the motor and the chain wheel are arranged in the shell, and the chain wheel is arranged at one end of the chain wheel shaft; the first driving gear is engaged with the first driven gear on the clutch, the second driving gear on the clutch is engaged with the second driven gear on the third transmission shaft, and the third driving gear on the third transmission shaft is engaged with the third driven gear on the chain wheel shaft; the motor drives the clutch shaft, the third transmission shaft and the chain wheel shaft to rotate in sequence through the motor shaft, so as to drive the chain wheel to rotate, thereby driving the ring chain to move.

[0016] In the conventional design, the friction plate is an independent component which is in contact with the gear through mechanical compression, and is prone to performance degradation due to wear or looseness. The utility model application directly sinters the friction material (copper-based powder) on the surface of the gear through powder metallurgy process to form metallurgical bonding. This integrated structure improves the bonding strength and eliminates the relative sliding problem between the friction plate and the gear in the conventional design. During the sintering process, the friction material and the gear substrate form a firm interface at high temperature to ensure the stability during long-term use.

[0017] In the new design of the ring chain electric hoist clutch of the utility model application, the powder metallurgy technology sinters the friction plate on the gear by using copper-based friction material, which significantly improves the stability, durability and manufacturing efficiency of the slip torque, while reducing the maintenance requirements. BRIEF DESCRIPTION OF DRAWINGS

[0018] The content expressed by each drawing of the specification and the marks in the drawings are briefly explained as follows:

[0019] Figure 1 It is a structural schematic view of the anti-overload ring chain electric hoist of example one;

[0020] Figure 2 It is a structural schematic view of the anti-overload ring chain electric hoist of example one; Figure 1 It is a sectional view at A-A in the middle;

[0021] Figure 3 It is a structural schematic view of the clutch of example one;

[0022] Figure 4 It is an exploded view of the clutch of example one;

[0023] In the drawings:

[0024] 1 is a clutch; 1-1 is a clutch shaft; 1-2 is a primary driven gear; 1-3 is a clutch seat; 1-4 is a friction plate; 1-5 is a fracture; 1-6 is a blocking ring; 1-7 is a first bearing; 1-8 is a disc spring; 1-9 is a secondary driving gear; 1-10 is a second bearing; 1-11 is a washer; 1-12 is a lock nut;

[0025] 2 is a motor;

[0026] 3 is a sprocket;

[0027] 4 is a housing;

[0028] 5 is an endless chain;

[0029] 6 is a motor shaft;

[0030] 7 is a primary driving gear;

[0031] 8 is a third transmission shaft;

[0032] 9 is a secondary driven gear;

[0033] 10 is a tertiary driving gear;

[0034] 11 is a sprocket shaft;

[0035] 12 is a tertiary driven gear. DETAILED DESCRIPTION

[0036] The utility model will be further described below in conjunction with the drawings of a non-limiting embodiment. However, it should be understood that these descriptions are only examples, and are not intended to limit the scope of the utility model. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the utility model.

[0037] EMBODIMENT

[0038] As shown in Figure 1 , 2 , an overload-preventing endless chain electric hoist comprises a housing 4 and an endless chain 5, and a motor 2, a motor shaft 6, a primary driving gear 7 arranged on the motor shaft 6, a clutch 1, a third transmission shaft 8, a secondary driven gear 9 and a tertiary driving gear 10 arranged on the third transmission shaft 8, a sprocket shaft 11, a tertiary driven gear 12 arranged on the sprocket shaft 11, and a sprocket 3 arranged at one end of the sprocket shaft 11 are arranged in the housing 4. The endless chain 5 is arranged on the sprocket 3.

[0039] As shown in Figure 3 , 4As shown, the clutch 1 includes a clutch shaft 1-1, and in turn, a check ring 1-6, a first bearing 1-7, a disc spring 1-8, two clutch seats 1-3 and friction plates 1-4, a primary driven gear 1-2, a secondary driving gear 1-9, a washer 1-11, a second bearing 1-10 and a lock nut 1-12 arranged on the clutch shaft 1-1. The two clutch seats 1-3 are arranged between the disc spring 1-8 and the secondary driving gear 1-9, the primary driven gear 1-2 is clamped between the two clutch seats 1-3, and the two friction plates 1-4 are arranged between the primary driven gear 1-2 and the clutch seats 1-3 adjacent to the two end faces of the primary driven gear 1-2. The two friction plates 1-4 are fixedly arranged on the two end faces of the primary driven gear 1-2. The friction plates 1-4 on the two end faces of the primary driven gear 1-2 are annular, and a plurality of fracture lines 1-5 are arranged on the annular friction plates 1-4 to separate the friction plates 1-4.

[0040] As shown in Figure 2 The primary driving gear 7 is engaged with the primary driven gear 1-2 on the clutch 1, the secondary driving gear 9 on the clutch 1 is engaged with the secondary driven gear 9 on the third transmission shaft 8, and the tertiary driving gear 10 on the third transmission shaft 8 is engaged with the tertiary driven gear 12 on the sprocket shaft 11. The motor 2 drives the clutch shaft 1-1, the third transmission shaft 8 and the sprocket shaft 11 in turn through the motor shaft 6 to rotate, so as to drive the sprocket 3 to rotate, thereby driving the endless chain 5 to move.

[0041] As shown in Figure 1 As shown in the table 1, the test results of the copper-based powder sintered integrated friction plate and the resin friction plate are compared. The test group adopts the anti-overload electric hoist with a rated lifting weight of 500 kg, and the clutch friction plate is made of copper-based powder material and is integrated with the primary driven gear through sintering process, which is the structure scheme proposed in the embodiment. The control group adopts the product with the same rated weight, and the clutch friction plate is made of resin material and is assembled separately with the primary driven gear. During the test, the maximum weight data of the hoist is recorded when the overload slipping of the equipment lasts for 3 seconds under static conditions. The results are shown in the following table 1.

[0042] Table 1 Comparison of lifting limit data of copper-based powder sintered integrated friction plate and resin friction plate

[0043]

[0044]

[0045] Total number of samples: 240 data points (20 rows x 12 columns); Experimental group (first 6 columns): copper-based powder sintered brake pad (20 x 6 = 120 samples); Control group (last 6 columns): separate resin brake pad (20 x 6 = 120 samples); Test index: lifting limit weight (unit: kg).

[0046] Data statistical analysis results

[0047] Table 2 Experimental group data analysis (experimental group - copper-based brake pad)

[0048] Sample No. Mean (kg) Standard Deviation Minimum Maximum Experiment Group 1 758.15 8.22 742 776 Experiment Group 2 753.60 12.32 737 778 Experiment Group 3 746.85 7.65 733 760 Experiment Group 4 749.55 5.05 740 759 Experiment Group 5 744.75 5.39 734 756 Experiment Group 6 668.95 7.14 728 748 Overall 736.98 2.62 236 778

[0049] Table 3 Control group data analysis (control group - resin brake pad)

[0050] Sample No. Mean (kg) Standard Deviation Minimum Maximum Control Group 1 758.05 65.35 685 879 Control Group 2 766.05 69.59 680 865 Control Group 3 783.85 68.36 671 869 Control Group 4 750.05 66.72 685 872 Control Group 5 773.90 63.84 680 899 Control Group 6 759.15 69.11 682 887 Overall 765.18 66.71 671 899

[0051] Note: Although the average value of the control group is slightly higher, the standard deviation is very large, and the volatility is significantly higher than that of the experimental group, which is not conducive to stability and safety control.

[0052] 1. Limit weight comparison

[0053] The average limit value of the control group is slightly higher than that of the experimental group (765 kg vs 737 kg), but the data of the experimental group is more concentrated and has lower dispersion; the control group has higher limit weight, but also has potential risk (large fluctuations). (See Table 2, Table 3)

[0054] 2. Stability (standard deviation) comparison

[0055] The standard deviation of the experimental group is less than 15 kg except for the sixth column; the standard deviation of all samples in the control group exceeds 60 kg, reflecting the high instability of slip torque control. The standard deviation of the experimental group is smaller and the data is more concentrated, indicating that the slip torque is more controllable; the experimental group does not have the same large fluctuations as the control group, which can be inferred that it has stronger durability; the experimental group's brake pad (copper-based sintered integral type) is superior to the traditional resin pad in performance stability, safety, and working condition adaptability. (See Table 2, Table 3)

[0056] In summary, the experimental group (copper-based friction plate) has an average lifting limit close to 750 kg, much higher than the rated 500 kg, indicating that the structure has good load redundancy; the control group has a slightly higher average limit, but the data is severely scattered and lacks reliability. Although the peak value of the copper-based friction plate is slightly lower, the overall performance is more "robust" and more suitable for high safety requirements. The standard deviation of each group in the experimental group is generally lower than 15 kg; the standard deviation of all groups in the control group is above 60 kg, with severe fluctuations; the copper-based friction plate can ensure the consistency and controllability of the slip torque, avoiding risks such as load out of control and slip delay. This embodiment uses powder metallurgy to sinter the copper-based friction plate on the gear surface, forming an integrated structure; this structure reduces problems such as loosening and slipping, and avoids performance degradation caused by aging and thermal deformation of resin plates. The structural integration, process integration, and performance stability of the copper-based sintered structure are fully supported by experimental data, with outstanding technical advantages.

[0057] Performance advantages of the anti-overload ring chain electric hoist of this embodiment:

[0058] Stable slip torque: The friction coefficient and wear resistance of the copper-based powder friction plate are more consistent, avoiding torque fluctuations caused by wear of resin friction plates.

[0059] High temperature resistance: Copper-based powder materials can maintain performance at high temperatures, suitable for high-heat environments generated by clutches under high load or frequent slipping.

[0060] Low maintenance requirements: Integrated design reduces the number of components, eliminating maintenance work caused by locking nut adjustment or friction plate replacement in traditional designs.

[0061] Long service life: The wear resistance and fatigue resistance of copper-based powder friction plates are superior to resin materials, extending the service life of the clutch.

[0062] Manufacturing advantages: Copper-based powder can directly form complex friction plate-gear structures, reducing the assembly steps of multiple components in traditional designs. High-precision mold forming ensures the consistency of the thickness and surface properties of the friction plate, further improving the stability of the slip torque.

[0063] In the description of the utility model, it is necessary to understand that if the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, it is only for the convenience of describing the utility model and simplifying the description, and it does not indicate or imply that the device or element indicated must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model. In addition, if the terms "first", "second" and the like appear, they are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the utility model, unless otherwise specified and limited, if the terms "mounting", "connection" and "connection" appear, they should be understood broadly, for example, they can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, can be electrically connected; can be directly connected, can be indirectly connected through an intermediate medium, or can be connected inside two elements. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0064] In the description of the utility model, it should be pointed out that, unless otherwise specified and limited, if the terms "mounting", "connection", "connection" appear, they should be understood broadly, for example, they can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, can be electrically connected; can be directly connected, can be indirectly connected through an intermediate medium, or can be connected inside two elements. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

Claims

1. An overload-preventing ring-chain electric hoist, comprising a clutch (1) with overload protection for connecting a motor (2) to a sprocket (3); the clutch (1) comprises a clutch shaft (1-1), a primary driven gear (1-2) sleeved on the clutch shaft (1-1), and two clutch seats (1-3) and friction plates (1-4); the primary driven gear (1-2) is clamped between the two clutch seats (1-3), and the two friction plates (1-4) are respectively arranged between the primary driven gear (1-2) and the clutch seat (1-3) adjacent to the two ends of the primary driven gear (1-2); characterized in that, Two friction plates (1-4) are fixedly arranged on the two end faces of the primary driven gear (1-2).

2. An overload protection ring chain electric hoist according to claim 1, characterized in that, The friction plates (1-4) are sintered on the two end faces of the primary driven gear (1-2) by copper-based powder.

3. An overload protection ring chain electric hoist according to claim 1, characterized in that, The friction plates (1-4) on the two end faces of the primary driven gear (1-2) are annular, and a plurality of fracture (1-5) are arranged on the annular to break the friction plates (1-4).

4. An overload protection ring chain electric hoist according to claim 1, characterized in that, The clutch (1) further comprises a check ring (1-6), a first bearing (1-7), a disc spring (1-8), a secondary driving gear (1-9), a washer (1-11), a second bearing (1-10) and a lock nut (1-12) arranged on the clutch shaft (1-1) in sequence; the two clutch seats (1-3) are arranged between the disc spring (1-8) and the secondary driving gear (1-9).

5. An overload protection ring chain electric hoist according to claim 1, characterized in that, Further comprising a housing (4) and a ring chain (5) arranged on the sprocket (3), and a motor shaft (6) arranged in the housing (4), a primary driving gear (7) arranged on the motor shaft (6), a third transmission shaft (8), a secondary driven gear (9) and a tertiary driving gear (10) arranged on the third transmission shaft (8), a sprocket shaft (11), and a tertiary driven gear (12) arranged on the sprocket shaft (11); the motor (2) and the sprocket (3) are arranged in the housing (4), and the sprocket (3) is arranged at one end of the sprocket shaft (11); the primary driving gear (7) is engaged with the primary driven gear (1-2) on the clutch (1), the secondary driving gear (1-9) on the clutch (1) is engaged with the secondary driven gear (9) on the third transmission shaft (8), and the tertiary driving gear (10) on the third transmission shaft (8) is engaged with the tertiary driven gear (12) on the sprocket shaft (11); the motor (2) drives the clutch shaft (1-1), the third transmission shaft (8) and the sprocket shaft (11) to rotate in sequence through the motor shaft (6), so as to drive the sprocket (3) to rotate, thereby driving the ring chain (5) to move.

Images