Heat-failure-resistant wet paper substrate type friction torque limiter for high-power scraper conveyor

Abstract

The invention discloses a heat-failure-resistant wet paper substrate type friction torque limiter for a high-power scraper conveyor, and belongs to the technical field of scraper conveyor torque limiting. The heat-failure-resistant wet paper substrate type friction torque limiter comprises n friction plates, the (n + 1) dual steel sheets and the friction sheets are alternately arranged in sequence to form 2n friction pairs; one of the friction plate and the dual steel sheet is provided with inner teeth, the other one of the friction plate and the dual steel sheet is provided with outer teeth, and the inner teeth and the outer teeth are used for being connected with the friction pair inner hub and the friction pair outer hub; a plurality of lubricating oil channels are processed at the spline tooth root of the friction pair inner hub; wherein the thickness of the dual steel sheet located in the axial middle area is larger than that of the dual steel sheets located in the two side areas, and the hole diameter of the lubricating oil channel in the friction pair inner hub in the axial middle area is larger than that of the two side areas. The thickened dual steel sheets can improve the heat capacity of a friction pair, the enlarged lubricating oil holes can improve the heat dissipation effect of the friction pair, and the heat failure deformation resistance of the friction pair is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of torque limiting, and in particular relates to a wet paper-based friction torque limiter for a high-power scraper conveyor that is resistant to thermal failure. Background Art

[0002] With the increasing scale of modern coal mining, scraper conveyors, as the key core equipment in coal mine comprehensive mining equipment, directly determine the coal mining efficiency and economic benefits of coal mines. In recent years, a complete technical system and advanced manufacturing level have been formed at home and abroad. Scraper conveyors are developing towards high power and long distance. At the same time, its related products have achieved many major technical and innovative results.

[0003] However, due to the harsh working conditions and large impact loads, although the drive system has electrical protection, there are many transmission components, the structure is complex and the volume is large. Due to the delay of electrical protection, when a fault occurs, the electrical protection system will not act immediately, and it will take a period of time to play a protective role, and it is impossible to immediately protect the transmission and motor system. At the same time, due to the large inertia of the scraper conveyor, there are still frequent problems such as chain breakage, transmission chain failure, and shutdown after overload during actual use, which leads to the suspension of coal mine production, seriously restricting the overall development of comprehensive mining equipment and the improvement of coal mining efficiency.

[0004] Therefore, it is necessary to install a torque limiter on the drive chain of the scraper conveyor. At the same time, installing the torque limiter at the low-speed end, that is, between the reducer and the sprocket shaft, has more significant advantages than arranging it in other positions of the transmission system. When the scraper conveyor encounters working conditions such as chain slabbing, chain jamming, and chain breaking, the torque limiter can play a good protective role for the entire transmission system, including the gear transmission part and the motor, and significantly improve the reliability and safety of the system.

[0005] The wet-type paper-based friction torque limiter has the advantages of simple structure, rapid power cut-off and high reliability. When sudden situations such as chain slacking, chain jamming and chain breaking occur, the load may frequently exceed the safety value. At this time, relative sliding occurs between the dual steel plates and the friction plates. Compared with dry friction, the wet-type paper-based friction pair can slip for a long time, and there is no need to worry about being damaged after a single overload. It has a longer service life; and the difference between the dynamic and static friction coefficients of the wet friction pair is small. After slipping, the time required for the conversion from dynamic friction to static friction is shorter, and the engagement can be restored in a shorter time, thereby ensuring that the power is not interrupted and the scraper conveyor runs more smoothly. Therefore, the wet-type paper-based friction torque limiter is a more ideal torque limiting device for high-power scraper conveyors.

[0006] Problems:

[0007] The friction plate and the dual steel plate are the core components of the friction torque limiter. They are radially large-sized thin plate disc structures. The large torque and long-term relative sliding friction determine that the friction pair has a large amount of friction heat loss during operation. Since the thermal conductivity of the paper-based friction material is weak, the friction loss caused by the slipping of the torque limiter is mainly dissipated by the dual steel plate. Therefore, the transient heat accumulation under high energy density input leads to ablation and peeling of the friction material of the friction plate, and significant and irreversible buckling deformation of the dual steel plate. At this time, the friction pair will experience rapid temperature rise, torque mutation and speed fluctuation, resulting in abnormal working performance or even failure, which directly affects the torque limiting performance, reliability and service life of the torque limiter.

[0008] At the same time, although placing the torque limiter at the low speed end has unique advantages for the scraper conveyor and its drive system, the low speed end will cause the torque limiter to have a larger torque, so the torque limiter is generally composed of multiple friction pairs, and the number of friction pairs of high-power and high-torque torque limiters can be as many as 40-50 pairs. The excessively large axial size structure will lead to poor heat dissipation conditions of the torque limiter away from the middle of the piston and the pressure plate, causing uneven distribution of the axial temperature field of multiple friction pairs, and the axial temperature gradient is more likely to cause thermal failure. Summary of the invention

[0009] In order to overcome the deficiencies in the prior art, the technical solution adopted by the present invention is:

[0010] A high-power scraper conveyor wet paper-based friction torque limiter resistant to thermal failure, comprising:

[0011] n friction plates;

[0012] n+1 pairs of steel plates, the pairs of steel plates and the friction plates are alternately arranged in sequence to form 2n friction pairs; one of the friction plate and the pairs of steel plates is provided with internal teeth, and the other of the friction plate and the pairs of steel plates is provided with external teeth, and the internal teeth and the external teeth are used for connection with the inner hub and the outer hub of the friction pair;

[0013] A plurality of lubricating oil channels are machined at the spline tooth roots of the friction pair inner hub, so that when the torque limiter performs overload protection, convection heat exchange of transient heat accumulation during relative sliding of the friction pair is achieved;

[0014] Wherein, the thickness of the pair of steel sheets located in the axial middle area is greater than the thickness of the pair of steel sheets located in the two side areas.

[0015] Furthermore, a through hole is provided at the tooth root of each friction pair inner hub to form an independent lubricating oil channel.

[0016] Furthermore, the hole diameter of the axial middle area of ​​the lubricating oil channel on the inner hub of the friction pair is larger than the hole diameter of the areas on both sides.

[0017] Furthermore, the plurality of lubricating oil channels are distributed in a spiral shape along the circumference of the friction pair inner hub.

[0018] Furthermore, the diameter of the lubricating oil channel corresponding to the pair of steel sheets located in the middle area is greater than the diameter of the lubricating oil channel corresponding to the pair of steel sheets located in the side areas.

[0019] Furthermore, the diameter of the hole from the first axial end to the axial 1 / 3 and from the axial 2 / 3 to the second axial end of the inner hub of the friction pair is b mm;

[0020] The diameter of the hole at the axial 1 / 3 to 2 / 3 of the inner hub of the friction pair is b+2mm to enhance the flow of lubricating oil in the middle part.

[0021] Furthermore, from the n / 3th dual steel sheet to the 2n / 3th dual steel sheet, the thickness of the dual steel sheet is a+1 mm, and when n / 3 and 2n / 3 are non-integers, they are rounded off; the thickness of the dual steel sheets at other positions is a mm.

[0022] Beneficial effects:

[0023] 1. The thickened dual steel sheets can increase the heat capacity of the friction pair, and the enlarged lubricating oil holes can improve the heat dissipation effect of the friction pair. The ultimate goal is to improve the ability of high-power multi-friction pairs, especially the friction pairs in the middle part, to resist thermal failure and deformation.

[0024] 2. On the basis of improving the ability to resist thermal failure, the speed and torque stability of the friction pair are improved, the torque limiting effect of the friction pair is enhanced, the motor and transmission system are protected, and the reliability and service life of the torque limiter and scraper conveyor are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the overall installation structure of a high-power scraper conveyor wet paper-based friction torque limiter that is resistant to heat failure provided by the present invention;

[0026] Figure 2 This is a partial enlarged view of the friction pair;

[0027] Figure 3 This is a partial enlarged view of the lubricating oil channel;

[0028] Figure 4 This is the developed diagram of the tooth surface of the lubricating oil channel;

[0029] In the figure: 1. sun gear shaft; 2. lubricating oil channel; 21. small lubricating oil channel; 22. large lubricating oil channel; 3. pressure plate; 4. planetary gear; 5. planetary carrier; 6. housing; 7. gear ring; 8. friction pair outer hub; 9. friction pair; 91. friction plate; 92. thin dual steel plate; 93. thick dual steel plate; 10. return spring; 11. piston; 12. control oil channel; 13. friction pair inner hub; 131. spline tooth top; 132. spline tooth root. DETAILED DESCRIPTION

[0030] The present invention provides a high-power scraper conveyor wet paper-based friction torque limiter that is resistant to heat failure. The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings to make it easier to understand and grasp.

[0031] Example 1

[0032] refer to Figure 1 - Figure 4 , a high-power scraper conveyor wet paper-based friction torque limiter resistant to thermal failure, comprising:

[0033] n friction plates;

[0034] n+1 pairs of steel plates, the pairs of steel plates and the friction plates are arranged alternately in sequence to form 2n friction pairs; one of the friction plate and the pairs of steel plates is provided with internal teeth, and the other of the friction plate and the pairs of steel plates is provided with external teeth, and the internal teeth and the external teeth are used for connection with the inner hub and the outer hub of the friction pair;

[0035] Multiple lubricating oil channels are machined at the spline tooth root of the inner hub of the friction pair. When the torque limiter is overload protected, convection heat transfer of transient heat accumulation during relative sliding of the friction pair is achieved.

[0036] Among them, the thickness of the dual steel sheets located in the axial middle area is greater than the thickness of the dual steel sheets located in the two side areas.

[0037] Among them, the thickness of the dual steel sheets located in the middle area is greater than the thickness of the dual steel sheets located in the two side areas, so as to increase the heat capacity of the dual steel sheets in the middle part.

[0038] In this embodiment, the friction plate and the dual steel plate are both annular structures. According to actual use conditions, it is preferred that the outer ring of the friction plate is provided with external teeth, and the inner ring of the dual steel plate is provided with internal teeth. Specifically, the internal teeth of the dual steel plate are matched and connected with the spline teeth of the friction pair inner hub, and the external teeth of the friction plate are matched and connected with the spline teeth of the friction pair outer hub.

[0039] In this embodiment, a through hole is provided at the tooth root of each friction pair inner hub to form an independent lubricating oil channel.

[0040] The hole diameter of the axial middle area of ​​the lubricating oil channel on the inner hub of the friction pair is larger than the hole diameter of the areas on both sides.

[0041] In this embodiment, a plurality of lubricating oil channels are distributed in a spiral shape along the circumference of the inner hub of the friction pair.

[0042] In this embodiment, the diameter of the lubricating oil passage corresponding to the dual steel sheets located in the middle area is greater than the diameter of the lubricating oil passage corresponding to the dual steel sheets located in the two side areas.

[0043] Specifically, the diameter of the hole from the first axial end to the axial 1 / 3 and from the axial 2 / 3 to the second axial end of the inner hub of the friction pair is b mm, which is a small lubricating oil passage 21;

[0044] The diameter of the hole at the axial 1 / 3 to 2 / 3 position of the inner hub of the friction pair is b+2mm, which is a large lubricating oil passage 22 to enhance the lubricating oil flow in the middle portion.

[0045] In this embodiment, from the n / 3th dual steel sheet to the 2n / 3th dual steel sheet, the dual steel sheets are thick dual steel sheets 93, and the thickness of the thick dual steel sheets 93 is a+1 mm, wherein n / 3 and 2n / 3 are rounded to the nearest integer when they are non-integers; the dual steel sheets at other positions are thin dual steel sheets 92, and the thickness of the thin dual steel sheets 92 is a mm.

[0046] The working principle is:

[0047] The sun gear shaft 1 is the input, connected to the fixed shaft gear reduction output end of the power end; the planetary carrier 5 is the output, connected to the drive sprocket of the scraper conveyor, wherein the planetary gear 4 is installed on the planetary carrier 5; the ring gear 7 is connected to the friction pair inner hub 13 through the friction pair outer hub 8 and multiple groups of friction pairs 9, and the friction pair inner hub 13 is connected to the box body 6 and fixed.

[0048] When the scraper conveyor works normally, the external hydraulic system provides high-pressure oil through the control oil channel 12, pushes the piston 11 and overcomes the reaction force of the return spring 10 to press the friction pair 9 axially toward the pressure plate 3. The friction plate 91 and the thin dual steel plate 92 and the thick dual steel plate 93 of the friction pair 9 generate friction force to realize the rigid connection between the friction pair outer hub 8 and the friction pair inner hub 13. At this time, the ring gear 7 is fixed, and the entire device is equivalent to an ordinary planetary reducer, realizing the reduction transmission of the scraper conveyor.

[0049] If the scraper conveyor encounters overload conditions such as chain jamming or chain slabs, when the torque of the friction pair exceeds the maximum torque it can withstand, the friction plate and the dual steel plate begin to slip to achieve flexible transmission, the ring gear begins to rotate to a floating state, and the output speed of the planetary carrier is 0. At this time, the torque transmitted by the drive motor, reduction transmission unit and scraper conveyor is the set slip torque of the friction pair, and the torque of the entire system is kept within a safe range.

[0050] Since the friction pair generates large friction pair heat loss during the slipping process, multiple lubricating oil channels 2 are processed at the spline tooth root 132 of the friction pair inner hub 13 to achieve heat dissipation of the friction pair; no lubricating oil channel 2 is set at the spline tooth top 131 of the friction pair inner hub 13.

[0051] In the high-power scraper conveyor wet paper-based friction torque limiter that is resistant to thermal failure provided in this embodiment, the thickened dual steel plates can increase the heat capacity of the friction pair, and the enlarged lubricating oil holes can improve the heat dissipation effect of the friction pair, which can improve the ability of high-power multi-friction pairs, especially the friction pairs in the middle part, to resist thermal failure and deformation.

[0052] On the basis of improving the ability to resist thermal failure, the speed and torque stability of the friction pair are improved, the torque limiting effect of the friction pair is enhanced, the motor and transmission system are protected, and the reliability and service life of the torque limiter and scraper conveyor are improved.

[0053] The above fully describes the technical solution of the present invention. It should be noted that the specific implementation of the present invention is not limited to the above description. All technical solutions formed by ordinary technicians in the field using equivalent or equivalent transformations in structure, method or function based on the spirit of the present invention fall within the protection scope of the present invention.

Claims

1. A high-power scraper conveyor wet paper-based friction torque limiter resistant to thermal failure, characterized in that: include: n friction plates; n+1 pairs of steel plates, wherein the pairs of steel plates and the friction plates are arranged alternately in sequence to form 2n friction pairs; One of the friction plate and the dual steel plate is provided with internal teeth, and the other of the friction plate and the dual steel plate is provided with external teeth, and the internal teeth and the external teeth are used for connection with the friction pair inner hub and the friction pair outer hub; A plurality of lubricating oil channels are machined at the spline tooth roots of the friction pair inner hub, so that when the torque limiter performs overload protection, convection heat exchange of transient heat accumulation during relative sliding of the friction pair is achieved; Wherein, the thickness of the pair of steel sheets located in the axial middle area is greater than the thickness of the pair of steel sheets located in the two side areas.

2. The high-power scraper conveyor wet paper-based friction torque limiter resistant to thermal failure according to claim 1 is characterized in that: A through hole is arranged at the tooth root of each friction pair inner hub to form an independent lubricating oil channel.

3. The high-power scraper conveyor wet paper-based friction torque limiter resistant to thermal failure according to claim 2 is characterized in that: The hole diameter of the axial middle area of ​​the lubricating oil channel on the inner hub of the friction pair is larger than the hole diameter of the areas on both sides.

4. The high-power scraper conveyor wet paper-based friction torque limiter resistant to thermal failure according to claim 3 is characterized in that: The plurality of lubricating oil channels are distributed in a spiral shape along the circumference of the friction pair inner hub.

5. The high-power scraper conveyor wet paper-based friction torque limiter resistant to thermal failure according to claim 4 is characterized in that: The diameter of the lubricating oil channel corresponding to the pair of steel sheets located in the middle area is greater than the diameter of the lubricating oil channel corresponding to the pair of steel sheets located in the two side areas.

6. The high-power scraper conveyor wet paper-based friction torque limiter resistant to thermal failure according to claim 5 is characterized in that: The diameter of the hole from the axial first end to the axial 1 / 3 and from the axial 2 / 3 to the axial second end of the inner hub of the friction pair is b mm; the diameter of the hole from the axial 1 / 3 to 2 / 3 of the inner hub of the friction pair is b+2mm to enhance the lubricating oil flow in the middle part.

7. The high-power scraper conveyor wet paper-based friction torque limiter resistant to thermal failure according to claim 1 is characterized in that: From the n / 3th dual steel sheet to the 2n / 3th dual steel sheet, the thickness of the dual steel sheet is a+1 mm, and when n / 3 and 2n / 3 are non-integers, they are rounded off; the thickness of the dual steel sheets at other positions is a mm.

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