Torque-limited sprocket assembly

Abstract

The present invention discloses a torque-limiting sprocket assembly, comprising: a sprocket body, a sprocket shaft and a friction torque-limiting mechanism. The sprocket shaft sleeve is arranged in the sprocket body, and the two ends pass through the sprocket body, and the sprocket shaft has a portion spaced opposite to the sprocket body. The friction torque-limiting mechanism is sleeved on the sprocket shaft, and the inner side surface and the outer side surface are respectively against the sprocket shaft and the sprocket body, and is used to provide friction force to transmit torque so that the sprocket body rotates with the sprocket shaft. The friction force between the friction torque-limiting mechanism and the sprocket shaft and the sprocket body is adjustable. The torque-limiting sprocket assembly of the present invention can not only ensure torque transmission under normal working conditions, but also realize the slipping torque-limiting function when faults such as chain jamming occur, play a protective role for the motor, transmission device or scraper chain, etc., and improve the reliability of the whole machine. It can meet the use requirements of different scenarios and has a wide range of applications. Since the friction torque-limiting mechanism is not easily damaged during the slipping process, it can be quickly put into production without manual recovery after the fault is eliminated, thereby improving economic benefits.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine transportation, and in particular to a torque-limiting sprocket assembly. Background Art

[0002] Scraper conveyor is the main equipment of coal mine fully mechanized mining working face. It pulls the scraper chain through the sprocket assembly located at the head and tail of the machine to transport coal and materials in the trough. During the operation of the coal mine scraper conveyor, the chain may get stuck, which will suddenly increase the output torque of the motor, resulting in motor burnout, reducer tooth breakage, scraper chain breakage and other faults, causing the working face to stop production.

[0003] Existing technical means usually adopt the following methods to protect this situation: 1. Use a torque limiter or hydraulic coupling as a protective device between the reducer and the motor. Since the torque limiter or hydraulic coupling is located at the high-speed end of the reducer, it cannot protect the reducer. Since the torque at the high-speed end is small, it is difficult to control the safety threshold range, and the torque limiter or hydraulic coupling itself has a large flywheel torque. 2. Use CST reducer, but it is large in size, and its torque limiter is placed inside the reducer, involving a relatively complex structure such as cooling and sealing, and the price is much higher than that of the same type of reducer. Maintenance and repair are quite complicated, and the maintenance cycle is long. 3. By monitoring the output current of the motor, the power supply is cut off when the current is too large, but since the power supply is cut off and the motor rotor cannot stop immediately, the huge inertia of the rotor will still cause damage to the reducer and chain. Summary of the invention

[0004] In order to solve the technical problems existing in the above-mentioned prior art, the present invention provides a torque-limiting sprocket assembly. The specific technical solution is as follows:

[0005] A torque-limiting sprocket assembly comprises: a sprocket body, a sprocket shaft and a friction torque-limiting mechanism; the sprocket shaft is sleeved inside the sprocket body, with both ends extending outside the sprocket body, and there is a portion on the sprocket shaft that is spaced opposite to the sprocket body; the friction torque-limiting mechanism is sleeved on the sprocket shaft, and the inner side surface and the outer side surface are respectively against the sprocket shaft and the sprocket body, and is used to provide friction force to transmit torque so that the sprocket body rotates with the sprocket shaft; the friction force between the friction torque-limiting mechanism and the sprocket shaft and the sprocket body is adjustable.

[0006] In a possible design, the friction torque limiting mechanism includes a wear-resistant sleeve and an expansion member, wherein the wear-resistant sleeve is sleeved on the sprocket shaft, and the expansion member is arranged outside the wear-resistant sleeve to provide radial force to generate friction force.

[0007] In a possible design, the expansion member is an expansion sleeve or a high-pressure oil bag.

[0008] In a possible design, a spiral oil groove is provided on the inner wall of the wear-resistant sleeve.

[0009] In a possible design, the outer wall of the sprocket body is provided with sprocket teeth for driving the chain to rotate.

[0010] In a possible design, the friction torque limiting mechanism includes a first friction torque limiting mechanism and a second friction torque limiting mechanism, and the first friction torque limiting mechanism and the second friction torque limiting mechanism are respectively close to two ends of the sprocket body.

[0011] In a possible design, one end of the sprocket shaft is mounted with a first bearing, a first bearing seat is mounted on the first bearing, the first bearing seat is connected to one end of the sprocket body, and the outer wall is flush with the outer wall of the sprocket body; the other end of the sprocket shaft is mounted with a second bearing, a second bearing seat is mounted on the second bearing, the second bearing seat is connected to the other end of the sprocket body, and the outer wall is flush with the outer wall of the sprocket body.

[0012] In a possible design, a pressure cover is provided at one end of the sprocket shaft, and the pressure cover is in contact with the end of the first bearing; and an end cover is connected to the first bearing seat.

[0013] In a possible design, a transparent cover is mounted on the sprocket shaft, the transparent cover is connected to the second bearing seat, and the other end of the sprocket shaft passes through the transparent cover and is connected to the transmission mechanism.

[0014] In a possible design, a sealing ring is provided between the transparent cover and the sprocket shaft, one end face of the sealing ring abuts against the second bearing, and the other end face of the sealing ring abuts against a locking nut sleeved on the sprocket shaft.

[0015] The main advantages of the technical solution of the present invention are as follows:

[0016] The torque-limiting sprocket assembly of the present invention uses the friction force provided by the friction torque-limiting mechanism to link the sprocket body and the sprocket shaft, which can not only ensure the torque transmission under normal working conditions, but also realize the slip torque-limiting function when a fault such as chain jamming occurs, thereby protecting the motor, transmission device or scraper chain, etc., and improving the reliability of the whole machine. By adjusting the friction force of the friction torque-limiting mechanism, the use requirements of different scenarios can be met, and the scope of application is relatively wide. Since the friction torque-limiting mechanism is not easily damaged during the slipping process, the working device can be quickly put into production without manual recovery after the fault is eliminated, thereby improving economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the embodiments of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 A schematic structural diagram of a torque-limiting sprocket assembly provided by one embodiment of the present invention;

[0019] Figure 2 A schematic structural diagram of a friction torque limiting mechanism in a torque limiting sprocket assembly provided in one embodiment of the present invention;

[0020] Figure 3 A partial enlarged view of a wear-resistant sleeve in a torque-limiting sprocket assembly provided in one embodiment of the present invention.

[0021] Description of reference numerals:

[0022] 1-sprocket body, 2-sprocket shaft, 3-friction torque limiting mechanism, 31-wear-resistant sleeve, 311-spiral oil groove, 32-expansion piece, 3a-first friction torque limiting mechanism, 3b-second friction torque limiting mechanism, 4a-first bearing, 4b-second bearing, 5a-first bearing seat, 5b-second bearing seat, 6-pressure cover, 7-end cover, 8-transparent cover, 9-sealing ring, 10-locking nut, 11-fixing sleeve, 12-distance sleeve. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] The technical solution provided by the embodiments of the present invention is described in detail below with reference to the accompanying drawings.

[0025] The embodiment of the present invention provides a torque-limiting sprocket assembly, as shown in the attached Figure 1 As shown, it includes: a sprocket body 1, a sprocket shaft 2 and a friction torque limiting mechanism 3; the sprocket shaft 2 is sleeved in the sprocket body 1, with both ends passing through the outside of the sprocket body 1, and there are parts on the sprocket shaft 2 that are spaced opposite to the sprocket body 1; the friction torque limiting mechanism 3 is sleeved on the sprocket shaft 2, and the inner side surface and the outer side surface are respectively against the sprocket shaft 2 and the sprocket body 1, and is used to provide friction force to transmit torque so that the sprocket body 1 rotates with the sprocket shaft 2; the friction force between the friction torque limiting mechanism 3 and the sprocket shaft 2 and the sprocket body 1 is adjustable.

[0026] The working principle of the torque-limiting sprocket assembly provided in the embodiment of the present invention is described below:

[0027] When in use, one end of the sprocket shaft 2 is connected to the transmission mechanism, and the driving motor drives the sprocket shaft 2 to rotate through the transmission mechanism. The sprocket body 1 is connected to the chain, and the sprocket body 1 drives the chain to rotate when it rotates. The sprocket body 1 and the sprocket shaft 2 are linked by the friction force of the friction torque limiting mechanism 3, and the maximum torque that can be transmitted by the friction force is the slip torque. When the torque is less than the slip torque, the sprocket body 1 rotates with the sprocket shaft 2, driving the chain to rotate, and this is the normal transportation working state. When the chain is stuck, the torque between the sprocket body 1 and the sprocket shaft 2 increases. When the torque is greater than or equal to the slip torque, the sprocket body 1 and the sprocket shaft 2 slip relative to each other, and the sprocket body 1 stops rotating. By setting the slip torque to be slightly larger than the torque under normal working state (for example, it can be 3 times that under normal working state), it can not only ensure the torque transmission under normal working state, but also prevent slipping when stuck and other phenomena occur, avoiding the generation of large torque to cause damage to the motor and / or scraper chain, and improving production safety performance. The friction torque limiting mechanism 3 will not be damaged during the slipping process, and can be put into normal use without manual restoration after the fault is eliminated. Furthermore, since the friction between the friction torque limiting mechanism 3 and the sprocket shaft 2 and the sprocket body 1 is adjustable, different friction forces correspond to different slipping torques, which can meet the torque limiting use requirements of different scenarios and has a wide range of applications.

[0028] It can be seen that the torque-limiting sprocket assembly provided by the embodiment of the present invention can link the sprocket body 1 and the sprocket shaft 2 through the friction force provided by the friction torque-limiting mechanism 3, which can not only ensure the torque transmission under normal working conditions, but also realize the slip torque-limiting function when a fault such as chain jamming occurs, thereby protecting the motor, transmission device or scraper chain, etc., and improving the reliability of the whole machine. By adjusting the friction force of the friction torque-limiting mechanism 3, the use requirements of different scenarios can be met, and the scope of application is relatively wide. Since the friction torque-limiting mechanism 3 is not easily damaged during the slipping process, the working device can be quickly put into production without manual recovery after the fault is eliminated, thereby improving economic benefits.

[0029] Optionally, in the torque-limiting sprocket assembly provided in the embodiment of the present invention, as shown in the attached Figure 1 and attached Figure 2 As shown, the friction torque limiting mechanism 3 includes a wear-resistant sleeve 31 and an expansion member 32. The wear-resistant sleeve 31 is sleeved on the sprocket shaft 2, and the expansion member 32 is arranged outside the wear-resistant sleeve 31. The radial force is generated by the expansion member 32. In this way, the magnitude of the radial force is controlled by the expansion degree of the expansion member 32, so that the friction force of the friction torque limiting mechanism 3 is adjustable. By setting the wear-resistant sleeve 31, the wear of the expansion member 32 is avoided, the service life is extended, and the reliability of use is improved.

[0030] The structure of the expansion member 32 is described below by way of example:

[0031] As an example, the expansion member 32 may be an expansion sleeve, and the expansion force of the expansion sleeve is used as the radial force, and the slipping torque is set by adjusting the size of the expansion force.

[0032] When adjusting the tensioning force, the degree of extrusion of the expansion sleeve can be controlled by filling expansion sleeves of different volumes between the wear-resistant sleeve 31 and the sprocket body 1, thereby achieving different tensioning forces; alternatively, the expansion sleeve can be fixed to the end face of the sprocket shaft 2 or the sprocket body 1 by bolts arranged along the axial direction, and different tensioning forces can be obtained by compressing the expansion sleeve to different degrees by rotating the bolts.

[0033] Alternatively, the expansion sleeve may include two outer rings, an inner ring, and a tension bolt. The two outer rings are installed on both sides of the inner ring, the inner ring and the outer ring are in contact through a conical contact surface, and the two outer rings are connected by the tension bolt. By tightening the bolts to bring the two outer rings closer, the axial size of the expansion sleeve is reduced and the radial size is increased, thereby achieving the purpose of tensioning.

[0034] As another example, the expansion member 32 may be a high-pressure oil bag, and the radial force is provided by filling the high-pressure oil bag with hydraulic oil. The radial force can be controlled by controlling the amount of hydraulic oil filled in the high-pressure oil bag, thereby setting the slip torque.

[0035] In the embodiment of the present invention, the maximum friction pair specific pressure of the friction torque limiting mechanism 3 can reach 180 MPa.

[0036] Optionally, to avoid heat accumulation during slipping, Figure 3 As shown, the inner wall of the wear-resistant sleeve 31 is provided with a spiral oil groove 311. With such a configuration, the lubricating oil can flow evenly through various parts of the wear-resistant sleeve 31 in the spiral oil groove 311, ensuring that the heat generated by the friction torque limiting mechanism 3 during slipping can be taken away by the lubricating oil in time, playing a cooling and protective role, and extending the service life of the wear-resistant sleeve 31.

[0037] In the embodiment of the present invention, the sprocket body 1 is connected to the chain to drive the chain to rotate. Figure 1 As shown, the outer wall of the sprocket body 1 is provided with sprocket teeth, which mesh with the chain to drive the chain to rotate.

[0038] In the embodiment of the present invention, there are two friction torque limiting mechanisms 3, namely, a first friction torque limiting mechanism 3a and a second friction torque limiting mechanism 3b, and the first friction torque limiting mechanism 3a and the second friction torque limiting mechanism 3b are respectively close to the two ends of the sprocket body 1. Such an arrangement makes the acting force between the sprocket body 1 and the sprocket shaft 2 symmetrically and evenly distributed, and the two friction torque limiting mechanisms 3 are respectively located at the two ends of the sprocket body 1, which is convenient for installation and maintenance.

[0039] Optionally, in the embodiment of the present invention, as shown in the attached Figure 1As shown, one end of the sprocket shaft 2 is provided with a first bearing 4a, on which a first bearing seat 5a is provided, the first bearing seat 5a is connected to one end of the sprocket body 1, and the outer wall of the first bearing seat 5a is flush with the outer wall of the sprocket body 1; the other end of the sprocket shaft 2 is provided with a second bearing 4b, on which a second bearing seat 5b is provided, the second bearing seat 5b is connected to the other end of the sprocket body 1, and the outer wall of the second bearing seat 5b is flush with the outer wall of the sprocket body 1. With such a configuration, on the one hand, the bearing and the bearing seat protect the friction torque limiting mechanism 3, preventing the friction torque limiting mechanism 3 from being damaged by impact, etc., and the lubricating oil can be added to the bearing seat to allow the lubricating oil to flow to the friction torque limiting mechanism 3, and the surface of the sprocket assembly can be made smooth, so that it is easy to rotate when slipping occurs.

[0040] The first bearing seat 5a can be in direct contact with one end of the sprocket body 1, or there is a gap between them, which is sealed by a seal. The second bearing seat 5b can be in direct contact with the other end of the sprocket body 1, or there is a gap between them, which is sealed by a seal.

[0041] In the embodiment of the present invention, in order to facilitate the blocking and limiting of the first bearing 4a and the first bearing seat 5a, as shown in the attached Figure 1 As shown, a pressure cap 6 is provided at one end of the sprocket shaft 2, and the pressure cap 6 contacts the end of the first bearing 4a; an end cap 7 is connected to the first bearing seat 5a. The pressure cap 6 can be connected to the end face of the sprocket shaft 2 by bolts, and the bolts are inserted through the through holes or screw holes on the pressure cap 6 and fixed in the screw holes on the sprocket shaft 2, so as to connect the pressure cap 6 with one end of the sprocket shaft 2. The pressure cap 6 partially covers the end of the bearing, plays a limiting role, and prevents the bearing from sliding off in translation. The end cap 7 can be connected to the first bearing seat 5a by bolts, and the bolts are inserted through the through holes or screw holes on the end cap 7 and fixed in the screw holes on the first bearing seat 5a, so as to connect the end cap 7 with the first bearing seat 5a. The diameter of the end cap 7 can be equal to the outer diameter of the first bearing seat 5a to make the end face flat.

[0042] Optionally, as attached Figure 1 As shown, a transparent cover 8 is mounted on the sprocket shaft 2, and the transparent cover 8 is connected to the second bearing seat 5b. The other end of the sprocket shaft 2 passes through the transparent cover 8 and is connected to the transmission mechanism. The transparent cover 8 is provided to block the second bearing 4b, which plays a protective and limiting role. Among them, the transparent cover 8 is an annular structure, and the transparent cover 8 and the second bearing seat 5b can be connected by bolts. The bolts pass through the through holes or screw holes on the transparent cover 8 and are inserted and fixed in the screw holes on the second bearing seat 5b to connect the transparent cover 8 and the second bearing seat 5b together. The transparent cover 8 can be in direct contact with the second bearing 4b, or the second bearing 4b can be tightly fixed by the fixing sleeve 11, that is, the two ends of the fixing sleeve 11 are respectively against the end faces of the second bearing 4b and the transparent cover 8.

[0043] Optionally, in order to position the first bearing 4a and the second bearing 4b, as shown in the attached Figure 1 As shown, the torque-limiting sprocket assembly provided in the embodiment of the present invention further includes a distance sleeve 12. A distance sleeve 12 is provided between the first bearing 4a and the first friction torque-limiting mechanism 3a, and the two ends of the distance sleeve 12 are respectively against the end faces of the first bearing 4a and the first friction torque-limiting mechanism 3a; a distance sleeve 12 is provided between the second bearing 4b and the second friction torque-limiting mechanism 3b, and the two ends of the distance sleeve 12 are respectively against the end faces of the second bearing 4b and the second friction torque-limiting mechanism 3b.

[0044] Optionally, in order to improve the sealing performance, such as the attached Figure 1 As shown, a sealing ring 9 is provided between the transparent cover 8 and the sprocket shaft 2, one end face of the sealing ring 9 contacts the second bearing 4b, and the other end face contacts the locking nut 10 sleeved on the sprocket shaft 2. Furthermore, a skeleton oil seal may be provided between the sealing ring 9 and the transparent cover 8, and the skeleton oil seal cooperates with the sealing ring 9 to achieve a sealing effect.

[0045] It is understandable that the outer wall of the sprocket shaft 2 may be processed with an external thread matched with the locking nut 10, and the locking nut 10 is threadedly mounted on the sprocket shaft 2 to clamp the sealing ring 9 at a preset position.

[0046] Optionally, in an embodiment of the present invention, the sprocket shaft 2 includes a large diameter section located in the middle and small diameter sections located on both sides of the large diameter section. The length of the large diameter section is smaller than the length of the sprocket body 1, and the diameter is equal to the inner diameter of the sprocket body 1, and the large diameter section is located inside the sprocket body 1. The diameter of the small diameter section is smaller than the inner diameter of the sprocket body 1, and the friction torque limiting mechanism 3 is mounted on the small diameter section at a position opposite to the inner wall of the end of the sprocket body 1. The end face of the friction torque limiting mechanism 3 abuts against the end face of the large diameter section. Furthermore, a recessed section may also be provided at a position of the end of the sprocket body 1 opposite to the small diameter section to accommodate the friction torque limiting mechanism 3.

[0047] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In addition, "front", "back", "left", "right", "upper" and "lower" in this article are all referenced to the placement state shown in the accompanying drawings.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A torque-limiting sprocket assembly, characterized in that: include: A sprocket body (1), a sprocket shaft (2) and a friction torque limiting mechanism (3); The sprocket shaft (2) is sleeved inside the sprocket body (1), with two ends extending outside the sprocket body (1), and there is a portion on the sprocket shaft (2) that is spaced and opposite to the sprocket body (1); The friction torque limiting mechanism (3) is sleeved on the sprocket shaft (2), and the inner side surface and the outer side surface are respectively against the sprocket shaft (2) and the sprocket body (1), and is used to provide friction force to transmit torque so that the sprocket body (1) rotates with the sprocket shaft (2); The friction force between the friction torque limiting mechanism (3), the sprocket shaft (2) and the sprocket body (1) is adjustable; The friction torque limiting mechanism (3) comprises a wear-resistant sleeve (31) and an expansion member (32), wherein the wear-resistant sleeve (31) is sleeved on the sprocket shaft (2), and the expansion member (32) is arranged outside the wear-resistant sleeve (31) and is used to provide radial force to generate friction force; The expansion member (32) is a high-pressure oil bag; the radial force is provided by filling the high-pressure oil bag with hydraulic oil; the magnitude of the radial force can be controlled by controlling the amount of hydraulic oil filled in the high-pressure oil bag, thereby setting the slip torque; The inner wall of the wear-resistant sleeve (31) is provided with a spiral oil groove (311), and the lubricating oil can flow evenly through various parts of the wear-resistant sleeve in the spiral oil groove, ensuring that the heat generated by the friction torque limiting mechanism during slippage can be promptly removed by the lubricating oil, playing a cooling and protective role, thereby extending the service life of the wear-resistant sleeve; The outer wall of the sprocket body (1) is provided with sprocket teeth for driving the chain to rotate; The friction torque limiting mechanism (3) comprises a first friction torque limiting mechanism (3a) and a second friction torque limiting mechanism (3b), wherein the first friction torque limiting mechanism (3a) and the second friction torque limiting mechanism (3b) are respectively close to two ends of the sprocket body (1); The sprocket shaft includes a large diameter section located in the middle and small diameter sections located on both sides of the large diameter section. The length of the large diameter section is less than the length of the sprocket body, and the diameter is equal to the inner diameter of the sprocket body. The large diameter section is located in the sprocket body, and the diameter of the small diameter section is less than the inner diameter of the sprocket body. The friction torque limiting mechanism is sleeved on the small diameter section at a position opposite to the inner wall of the end of the sprocket body. The end face of the friction torque limiting mechanism abuts against the end face of the large diameter section. A recessed section is provided at a position of the end of the sprocket body opposite to the small diameter section for accommodating the friction torque limiting mechanism. One end of the sprocket shaft (2) is sleeved with a first bearing (4a), the first bearing (4a) is sleeved with a first bearing seat (5a), the first bearing seat (5a) is connected to one end of the sprocket body (1), and the outer wall of the first bearing seat (5a) is flush with the outer wall of the sprocket body (1); The other end of the sprocket shaft (2) is sleeved with a second bearing (4b), the second bearing (4b) is sleeved with a second bearing seat (5b), the second bearing seat (5b) is connected to the other end of the sprocket body (1), and the outer wall of the second bearing seat (5b) is flush with the outer wall of the sprocket body (1).

2. The torque-limiting sprocket assembly according to claim 1, characterized in that: A pressure cover (6) is provided at one end of the sprocket shaft (2), and the pressure cover (6) is in contact with an end of the first bearing (4a); An end cover (7) is connected to the first bearing seat (5a).

3. The torque-limiting sprocket assembly according to claim 2, characterized in that: A transparent cover (8) is mounted on the sprocket shaft (2), the transparent cover (8) is connected to the second bearing seat (5b), and the other end of the sprocket shaft (2) passes through the transparent cover (8) and is connected to the transmission mechanism.

4. The torque-limiting sprocket assembly according to claim 3, characterized in that: A sealing ring (9) is provided between the transparent cover (8) and the sprocket shaft (2); one end face of the sealing ring (9) abuts against the second bearing (4b), and the other end face abuts against a locking nut (10) sleeved on the sprocket shaft (2).

Images