Overload protection device
Through the tapered surface contact structure and torque adjustment mechanism of the inner and outer rings, the problems of high processing costs and inaccurate transmission of torque of the existing overload protection devices are solved, and low-cost and high-precision torque transmission and continuous use are achieved.
Patent Information
- Application Number
- CN202411836438.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-02-01
- Filing Date
- 2024-12-13
- Publication Date
- 2025-08-01
AI Technical Summary
The existing overload protection devices have problems such as high processing costs, inaccurate transmission torque, difficult to increase transmission torque, and inability to be used continuously under overload conditions.
The inner ring and outer ring structure are adopted, and the first conical surface and the second conical surface are contacted and inserted between the inner rotating member and the outer rotating member. Combined with the torque adjustment mechanism, the torque is transmitted using the wedge effect, and a large torque transmission is achieved through the axial pressing of the inner ring and the outer ring.
It achieves simple structure and low processing cost, can increase the transmitted torque, improve the accuracy of the allowed torque, and can still be used continuously under overload state.
Smart Images
Figure CN120402543A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an inner rotating member and an outer rotating member that are configured to rotate relative to each other coaxially, and an overload protection device that can transmit torque between the inner rotating member and the outer rotating member and can cut off torque transmission for torques above the allowable torque. Background Art
[0002] There is a well-known overload protection device that can cut off torque transmission for torques above the allowable torque when transmitting torque between two shafts.
[0003] For example, there is a well-known configuration that can transmit torque by pressing and using static friction force, similar to a friction plate type surface clutch or the like, and by appropriately setting the pressing force, it can cope with overload by sliding.
[0004] In addition, as disclosed in Patent Document 1, there is a well-known overload protection device that can transmit torque between an inner rotating member and an outer rotating member that are configured to rotate relative to each other coaxially, and can cut off torque transmission for torques above the allowable torque.
[0005] The overload protection device described in Patent Document 1 is configured such that a plurality of engaging portions (221) in a concave arc shape are provided on the inner peripheral surface of the outer rotating member (second body 20), and torque is transmitted by pressing the driving member (30) from the inner rotating member (first body 10) toward the outer peripheral side and pressing it against the engaging portions (221). For torques above the allowable torque, torque transmission is cut off by moving the driving member (30) against the pressing force toward the inner rotating member side.
[0006] Patent Document
[0007] Patent Document 1: Japanese Patent No. 7006664 Gazette Summary of the Invention
[0008] Since a clutch having the same configuration as a well-known surface clutch or the like requires a large pressing force for the transmitted torque, and when fastening with screws or the like, the torque at which sliding starts varies greatly with a small difference in fastening force, there is a problem that it is difficult to accurately set the cut-off torque.
[0009] In addition, although the overload protection device described in Patent Document 1 is composed of a torque transmission mechanism between the inner rotating member and the outer rotating member and can be miniaturized, the inner rotating member and the outer rotating member have complex shapes, so there is a problem of increased processing costs.
[0010] In addition, since there is only one torque transmission portion on the circumference and at most the number of torque transmission portions cannot exceed the number of engaging portions (221), it is difficult to increase the transmitted torque.
[0011] Moreover, there are restrictions on the pressing force of the elastic member that applies force to the driving member (30), making it difficult to increase the transmitted torque. In addition, since the elastic member applies a large pressing force in a short stroke in a small space, there is a problem that it is difficult to improve the accuracy of the set allowable torque.
[0012] In order to obtain a large transmitted torque, it is also possible to consider using the limit of the allowable torque of a general cam one-way clutch as an overload protection device.
[0013] However, when the cam clutch exceeds the limit of the allowable torque, the torque transmission will be cut off and cannot be restored to the torque transmission state again. Therefore, although it can be used as an overload protection device in an emergency, there is the following problem, that is, even in an overload state, if it returns to the normal torque, it cannot be applied to continuous use applications.
[0014] The present invention is an invention that solves these problems. The technical problem to be solved is to provide an overload protection device with a simple structure, low processing cost, capable of increasing the transmitted torque, capable of improving the accuracy of the set allowable torque, and capable of continuous use even in an overload state as long as it returns to the normal torque.
[0015] The present invention is an overload protection device that can perform torque transmission between an inner rotating member and an outer rotating member that are arranged to be relatively rotatable coaxially, and can cut off torque transmission for torques above the allowable value. It can solve the above problems by the following means, that is, it has an inner ring, an outer ring, and a torque adjustment mechanism. The inner ring has an inner circumferential transmission surface that contacts the outer circumferential surface of the inner rotating member and a first conical surface on the outer peripheral side. The outer ring has an outer circumferential transmission surface that contacts the inner circumferential surface of the outer rotating member and a second conical surface that contacts the first conical surface of the inner ring. The inner ring and the outer ring are configured to be inserted between the inner rotating member and the outer rotating member in a state of being in contact through the first conical surface and the second conical surface, and the torque adjustment mechanism is configured to be able to press the inner ring and the outer ring in a manner that makes them approach each other axially.
[0016] According to the invention related to Technical Solution 1, since the inner ring and the outer ring are inserted between the inner rotating member and the outer rotating member in a state of being in contact through the first conical surface and the second conical surface, and are configured to be able to press the inner ring and the outer ring in a manner that makes them approach each other axially, a large torque can be transmitted through the wedge effect.
[0017] In addition, it has a simple structure and low processing cost. Even when in an overload state, as long as it returns to the normal torque, it can be continuously used. Moreover, even during overload, it can transmit a certain torque.
[0018] In addition, since a relatively large axial pressing stroke can be obtained, the accuracy of the set allowable torque can be improved.
[0019] According to the configuration described in Technical Solution 2, since the torque adjustment mechanism includes: an internal thread hole provided axially on the outer ring; a screw through hole provided on the inner ring; and a screw member that passes through the screw through hole and is screwed with the internal thread hole, the number of components is small and a simpler structure can be achieved.
[0020] According to the configuration described in Technical Solution 3, by providing a pressing member that presses the inner ring and / or the outer ring against the limiting portion, the clearance between the inner rotating member and the outer rotating member can be reduced, and the inner ring and the outer ring can be reduced, enabling miniaturization in the radial direction.
[0021] According to the configuration described in Technical Solution 4, by setting the static friction force between the inner peripheral transmission surface of the inner ring and the outer peripheral surface of the inner rotating member to be smaller than the static friction force between the outer peripheral transmission surface of the outer ring and the inner peripheral surface of the outer rotating member, the surface that slides when the allowable torque is exceeded can be specified, and the allowable torque can be set more accurately.
[0022] According to the configurations described in Technical Solutions 5-7, damage to the respective surfaces caused by sliding when the allowable torque is exceeded can be suppressed, so it can be continuously used even after returning to the normal torque.
[0023] In addition, adhesion in the long-term close contact state (temporal change of the allowable torque) and generation of noise during sliding can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 is a partial cross-sectional side view of the overload protection device according to the first embodiment of the present invention.
[0025] Figure 2 is Figure 1 a perspective view of the inner ring and the outer ring of
[0026] Figure 3 is Figure 1 an exploded perspective view of the inner ring and the outer ring of
[0027] Figure 4 is a partial cross-sectional side view of the overload protection device according to the second embodiment of the present invention.
[0028] Figure 5 isFigure 4 ( Figure 6 ) Exploded perspective view of the inner ring and outer ring.
[0029] Figure 6 It is a partial cross-sectional side view of the overload protection device according to the 3rd embodiment of the present invention.
[0030] Reference Signs
[0031] 100 - Overload protection device; 110 - Outer rotating member; 111 - Internal threaded hole; 112 - Restriction portion; 120 - Inner rotating member; 121 - Internal threaded hole; 130 - Inner ring; 131 - First conical surface; 132 - Screw through-hole; 133 - Inner circumferential transmission surface; 140 - Outer ring; 141 - Second conical surface; 142 - Internal threaded hole; 143 - Outer circumferential transmission surface; 150 - Screw member; 160 - Pressing member; 161 - Screw through-hole. Detailed Description of the Invention
[0032] Refer to Figures 1 to 6 The embodiments of the present invention will be described. However, the present invention is not limited to these embodiments.
[0033] (Embodiment)
[0034] As Figures 1 - 3 shown, the overload protection device 100 according to the 1st embodiment of the present invention includes: an inner rotating member 120 and an outer rotating member 110, which are arranged to be relatively rotatable coaxially; an inner ring 130 and an outer ring 140, which perform torque transmission between the inner rotating member 120 and the outer rotating member 110.
[0035] The outer circumferential surface of the inner rotating member 120, the inner circumferential surface of the outer rotating member 110, the inner circumferential surface of the inner ring 130, and the outer circumferential surface of the outer ring 140 are each cylindrical.
[0036] The inner ring 130 has an inner circumferential transmission surface 133 that contacts the outer circumferential surface of the inner rotating member 120 and a first conical surface 131 on the outer peripheral side.
[0037] The outer ring 140 has an outer circumferential transmission surface 143 that contacts the inner circumferential surface of the outer rotating member 110 and a second conical surface 141 that contacts the first conical surface 131 of the inner ring 130.
[0038] The inner ring 130 and the outer ring 140 are configured to be inserted between the inner rotating member 120 and the outer rotating member 110 in a state of being in contact through the first conical surface 131 and the second conical surface 141.
[0039] On the outer ring 140, an internal threaded hole 142 is axially provided. On the inner ring 130, a screw through hole 132 is provided. By passing a screw member 150 through the screw through hole 132 and screwing it into the internal threaded hole 142 for fastening, the inner ring 130 and the outer ring 140 can be pressed in a manner of approaching each other axially. Moreover, by applying a force in the direction of expanding between the outer peripheral surface of the inner rotating member 120 and the inner peripheral surface of the outer rotating member 110 by using the first conical surface 131 and the second conical surface 141, torque transmission can be carried out by using the static friction force between the inner peripheral transmission surface 133 and the outer peripheral surface of the inner rotating member 120 and the static friction force between the outer peripheral transmission surface 143 and the inner peripheral surface of the outer rotating member 110.
[0040] In the present embodiment, when the screw member 150 is tightened, the static friction force between the inner peripheral transmission surface 133 and the outer peripheral surface of the inner rotating member 120 is smaller than the static friction force between the outer peripheral transmission surface 143 of the outer ring 140 and the inner peripheral surface of the outer rotating member 110.
[0041] In addition, in the present embodiment, the surface of the inner peripheral transmission surface 133 of the inner ring 130 is coated with a high-hardness material such as VC, CrN, or DLC, which has excellent wear resistance and durability, and the surface is hard and smooth, so the friction coefficient is stable.
[0042] Thus, when the rotational transmission is cut off due to the allowable torque as described above, the inner peripheral transmission surface 133 of the inner ring 130 with excellent wear resistance and durability will inevitably slide, so that the allowable torque can be stably maintained even if the number of operations increases.
[0043] In addition, since the relationship between the tightening amount of the screw member 150 and the allowable torque (the static friction force between the inner peripheral transmission surface 133 and the outer peripheral surface of the inner rotating member 120) is also stable, the allowable torque can be accurately set.
[0044] Preferably, the hardness of the surface is HV1500 or more.
[0045] As Figure 4 , 5 shown, the overload protection device 100b according to the second embodiment of the present invention includes: an inner rotating member 120 and an outer rotating member 110b, which are arranged to be relatively rotatable coaxially; an inner ring 130b and an outer ring 140b, which perform torque transmission between the inner rotating member 120 and the outer rotating member 110b; and a pressing member 160, which presses the outer ring 140b axially.
[0046] The outer peripheral surface of the inner rotating member 120, the inner peripheral surface of the outer rotating member 110b, the inner peripheral surface of the inner ring 130b, and the outer peripheral surface of the outer ring 140b are respectively in a cylindrical shape.
[0047] In addition, on the inner circumference of the outer rotating member 110b, a restricting portion 112 for restricting the axial movement of the inner ring 130b is provided.
[0048] The inner ring 130b has an inner circumferential transmission surface 133 that contacts the outer peripheral surface of the inner rotating member 120 and a first tapered surface 131 on the outer peripheral side.
[0049] The outer ring 140b has an outer circumferential transmission surface 143 that contacts the inner circumferential surface of the outer rotating member 110b and a second tapered surface 141 that contacts the first tapered surface 131 of the inner ring 130b.
[0050] The inner ring 130b and the outer ring 140b are configured to be inserted between the inner rotating member 120 and the outer rotating member 110b in a state of being in contact through the first tapered surface 131 and the second tapered surface 141.
[0051] The pressing member 160 is provided with a screw through-hole 161, is slightly fitted with the inner rotating member 120, and is configured to be able to axially press the outer ring 140b inserted between the inner rotating member 120 and the outer rotating member 110b.
[0052] On the outer rotating member 110b, an internal thread hole 111 is provided axially. By screwing and fastening the screw member 150 through the screw through-hole 161 of the pressing member 160 and the internal thread hole 111, the inner ring 130b and the outer ring 140b can be pressed in a manner of approaching each other axially by the pressing member 160 and the restricting portion 112 of the outer rotating member 110b. Moreover, by applying a force in a direction to expand between the outer peripheral surface of the inner rotating member 120 and the inner peripheral surface of the outer rotating member 110 by using the first tapered surface 131 and the second tapered surface 141, torque transmission can be performed by the static friction force between the inner circumferential transmission surface 133 and the outer peripheral surface of the inner rotating member 120b, the static friction force between the first tapered surface 131 and the second tapered surface 141, and the static friction force between the outer circumferential transmission surface 143 and the inner circumferential surface of the outer rotating member 110b.
[0053] In the present embodiment, when the screw member 150 is tightened, the static friction force between the inner circumferential transmission surface 133 and the outer peripheral surface of the inner rotating member 120 is smaller than the static friction force between the outer circumferential transmission surface 143 of the outer ring 140b and the inner circumferential surface of the outer rotating member 110b and the static friction force between the first tapered surface 131 and the second tapered surface 141.
[0054] In addition, in the present embodiment, the surface of the inner circumferential transmission surface 133 of the inner ring 130b is also coated with a high-hardness material such as VC, CrN, DLC, etc. Since the wear resistance and durability are excellent, and the surface is hard and smooth, the friction coefficient is very stable.
[0055] Therefore, when the rotational transmission is cut off due to the above-mentioned allowable torque, the inner circumferential transmission surface 133 of the inner ring 130b, which has excellent wear resistance and durability, will inevitably slide. Thus, even if the number of operations increases, the allowable torque can be stably maintained.
[0056] In addition, since the relationship between the tightening amount of the screw member 150 and the allowable torque (the static friction force between the inner circumferential transmission surface 133 and the outer circumferential surface of the inner rotating member 120) is also stable, the allowable torque can be accurately set.
[0057] Furthermore, although in the present embodiment, since the inner ring 130b and the outer ring 140b can be made thinner together, no cutout for deformation is provided, but it is also possible to provide a cutout at one position on the circumference, similar to the inner ring 130 and the outer ring 140 of the first embodiment.
[0058] As Figure 5 、 6 shown, the overload protection device 100c according to the third embodiment of the present invention includes: an inner rotating member 120c and an outer rotating member 110c, which are arranged to be relatively rotatable coaxially; an inner ring 130c and an outer ring 140c, which transmit the torque between the inner rotating member 120c and the outer rotating member 110c; and a pressing member 160c, which presses the outer ring 140c in the axial direction.
[0059] The outer circumferential surface of the inner rotating member 120c, the inner circumferential surface of the outer rotating member 110c, the inner circumferential surface of the inner ring 130c, and the outer circumferential surface of the outer ring 140c are each in a cylindrical shape.
[0060] In addition, on the inner circumference of the outer rotating member 110c, a restricting portion 112 for restricting the axial movement of the outer ring 140c is provided, and the outer rotating member 110c can restrict the movement of the pressing member 160c described later in the pressing direction relative to the inner rotating member 120c.
[0061] The inner ring 130c has an inner circumferential transmission surface 133 that contacts the outer circumferential surface of the inner rotating member 120c and a first conical surface 131 on the outer peripheral side.
[0062] The outer ring 140c has an outer circumferential transmission surface 143 that contacts the inner circumferential surface of the outer rotating member 110c and a second conical surface 141 that contacts the first conical surface 131 of the inner ring 130c.
[0063] The inner ring 130c and the outer ring 140c are configured to be inserted between the inner rotating member 120c and the outer rotating member 110c in a state where they are in contact through the first conical surface 131 and the second conical surface 141.
[0064] The pressing member 160c is provided with a screw through-hole 161, is slightly fitted with the inner rotating member 120c, and is configured to be able to axially press the outer ring 140c inserted between the inner rotating member 120c and the outer rotating member 110c.
[0065] On the inner rotating member 120c, an internal thread hole 121 is axially provided. By screwing and fastening the screw member 150 through the screw through-hole 161 of the pressing member 160c and the internal thread hole 121, the inner ring 130c and the outer ring 140c can be pressed in a manner of approaching each other axially by the pressing member 160c and the restricting portion 112 of the outer rotating member 110c. The restricting portion 112 of the outer rotating member 110c can restrict the movement of the pressing member 160c relative to the inner rotating member 120c in the pressing direction. Moreover, by applying a force in the direction of expanding between the outer peripheral surface of the inner rotating member 120c and the inner peripheral surface of the outer rotating member 110c by using the first tapered surface 131 and the second tapered surface 141, torque transmission can be carried out by using the static friction force between the inner peripheral transmission surface 133 and the outer peripheral surface of the inner rotating member 120c, the static friction force between the first tapered surface 131 and the second tapered surface 141, and the static friction force between the outer peripheral transmission surface 143 and the inner peripheral surface of the outer rotating member 110b.
[0066] In the present embodiment, similar to the second embodiment, when the screw member 150 is tightened, the static friction force between the inner peripheral transmission surface 133 and the outer peripheral surface of the inner rotating member 120c is smaller than the static friction force between the outer peripheral transmission surface 143 of the outer ring 140c and the inner peripheral surface of the outer rotating member 110c and the static friction force between the first tapered surface 131 and the second tapered surface 141.
[0067] In addition, in the present embodiment, the surface of the inner peripheral transmission surface 133 of the inner ring 130c is also coated with a high-hardness material such as VC, CrN, or DLC. Since the wear resistance and durability are excellent, and the surface is hard and smooth, the friction coefficient is also stable.
[0068] Thus, when the rotational transmission is cut off due to the allowable torque as described above, the inner peripheral transmission surface 133 of the inner ring 130c with excellent wear resistance and durability will surely slide, and the allowable torque can be stably maintained even if the number of operations increases.
[0069] In addition, since the relationship between the tightening amount of the screw member 150 and the allowable torque (the static friction force between the inner peripheral transmission surface 133 and the outer peripheral surface of the inner rotating member 120c) is also stable, the allowable torque can be accurately set.
[0070] In addition, although in the present embodiment, when the allowable torque is exceeded, the contact portion between the outer ring 140c and the pressing member 160 also slides, since the axial pressing force of this contact portion is smaller than the radial pressing force of other surfaces and its static friction force is small, it does not pose a problem in setting the allowable torque.
[0071] In each of the above embodiments, the allowable torque during use can be set by a torque wrench or the like by setting the tightening torque.
[0072] In addition, the allowable torque during use can also be managed by the rotation angle of the screw member 150. When there is a gap between the pressing member 160 and the outer rotating member 110b, and between the pressing member 160c and the inner rotating member 120c as in the second and third embodiments, this interval can also be used for management, and it can also be set to a specified allowable torque by tightening until there is no gap.
[0073] As described above, although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made on the premise of the present invention described within the scope of the technical solution.
[0074] For example, it can also be configured to project a screw shaft instead of the screw hole in each embodiment and thread a nut member.
[0075] In addition, as a mechanism for moving the pressing member in the pressing direction, it can also be configured such that the pressing member itself is directly threaded with the inner rotating member or the outer rotating member and can move axially.
Claims
1. An overload protection device capable of torque transmission between an inner rotating member and an outer rotating member that are configured to be relatively rotatable coaxially, and capable of cutting off torque transmission for torques above an allowable value, characterized in that it has an inner ring, an outer ring, and a torque adjustment mechanism, the inner ring has an inner peripheral transmission surface in contact with the outer peripheral surface of the inner rotating member and a first conical surface on the outer peripheral side, the outer ring has an outer peripheral transmission surface in contact with the inner peripheral surface of the outer rotating member and a second conical surface in contact with the first conical surface of the inner ring, the inner ring and the outer ring are configured to be inserted between the inner rotating member and the outer rotating member in a state of being in contact through the first conical surface and the second conical surface, the torque adjustment mechanism is configured to be able to press the inner ring and the outer ring so as to approach each other in the axial direction.
2. The overload protection device according to claim 1, characterized in that the torque adjustment mechanism includes: an internal thread hole provided on the outer ring in the axial direction; a screw through hole provided on the inner ring; and a screw member passing through the screw through hole and screwed into the internal thread hole.
3. The overload protection device according to claim 1, characterized in that the torque adjustment mechanism includes: a restricting portion provided on the inner rotating member and / or the outer rotating member to restrict axial movement of the inner ring and / or the outer ring; a pressing member pressing the inner ring and / or the outer ring toward the restricting portion; an internal thread hole provided on the inner rotating member or the outer rotating member in the axial direction; a screw through hole provided on the pressing member; and a screw member passing through the screw through hole and screwed into the internal thread hole.
4. The overload protection device according to claim 1, characterized in that the static friction force between the inner peripheral transmission surface and the outer peripheral surface of the inner rotating member is smaller than the static friction force between the outer peripheral transmission surface and the inner peripheral surface of the outer rotating member.
5. The overload protection device according to claim 1, characterized in that the inner peripheral transmission surface is a surface-treated surface.
6. The overload protection device according to claim 5, characterized in that the surface treatment of the inner peripheral transmission surface is a coating treatment using a high-hardness material.
7. The overload protection device according to claim 6, characterized in that the surface of the inner peripheral transmission surface has a hardness of HV1500 or more.