Torque limiter

Abstract

To provide a novel torque limiter that prevents one working piece 44 of two axially adjacent braking torque applying means 8 from interfering with the other working piece 44, thereby stabilizing the magnitude of the braking torque provided by the braking torque applying means 8. [Solution] At a circumferential position on the inner peripheral edge of the base 42 of the braking torque applying means 8 where the working piece 44 is not provided, a support piece 46 extending axially beyond the working piece 44 and a receiving piece 48 extending radially inward are provided. The support piece 46 and the receiving piece 48 of one of the two braking torque applying means 8, which are stacked in the axial direction, are aligned in the circumferential direction.

Description

【Technical Field】 【0001】 The present invention relates to a torque limiter. 【Background Art】 【0002】 Conventionally, as shown in Patent Document 1 below, there are an inner member rotatable relative to a common central axis and an outer member accommodating at least a part of the inner member, and braking torque applying means engaged with the outer member and non-rotatable with respect to the outer member and applying a required braking torque to the relative rotation. The braking torque applying means includes an annular base portion whose inner peripheral surface faces the cylindrical outer peripheral surface of the inner member, and at the inner peripheral edge of the base portion, there is provided an acting piece extending obliquely inward in the radial direction and axially, and the inner surface of the extending end portion is in close contact with the outer peripheral surface of the inner member. There exists a torque limiter in which a plurality of the braking torque applying means are stacked and arranged in the axial direction. Such a torque limiter may be referred to as a torque hinge, an angular position holding device, etc. depending on the usage mode and the like. one side 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent No. 3912724 【Summary of the Invention】 【Problems to be Solved by the Invention】<00000​​​​In the torque limiter shown in Patent Document 1, due to the arrangement of multiple braking torque applying means stacked in the axial direction, if, for example, the braking torque means is excessively pressed into the inner member or the braking torque means is arranged at an inclination with respect to the axial direction, there is a risk that one working piece of two axially adjacent braking torque applying means may interfere with the other working piece. In a torque limiter, it is necessary to strictly control the magnitude of the required braking torque provided by the braking torque applying means, and if one working piece of two axially adjacent braking torque applying means interferes with the other working piece, the magnitude of the required braking torque will vary, which is undesirable. 【0005】 The present invention has been made in view of the above facts, and its main technical problem is to provide a novel and improved torque limiter in which interference between one working piece of two axially adjacent braking torque applying means and the other working piece is prevented, thereby stabilizing the magnitude of the braking torque provided by the braking torque applying means. [Means for solving the problem] 【0006】 As a result of diligent study, the inventors have found that at a circumferential position on the inner peripheral edge of the base of the braking torque applying means where no working piece is provided, a support piece extending axially beyond the working piece to one side in the axial direction and a receiving piece extending radially inward are provided, and in the axial direction The receiving piece of the braking torque applying means located on one side in the axial direction of two adjacent braking torque applying means is positioned to be aligned in the circumferential direction with the support piece of the braking torque applying means located on the other side in the axial direction. By doing so, we found that the main technical challenges mentioned above could be solved. 【0007】 That is, according to the first aspect of the present invention, as a torque limiter that solves the above main technical problem, the present invention comprises an inner member that is rotatable relative to a common central axis and an outer member that houses at least a part of the inner member, and a braking torque applying means that is engaged with the outer member, is not rotatable relative to the outer member, and applies a required braking torque to the relative rotation, The braking torque applying means comprises an annular base whose inner circumferential surface faces the cylindrical outer circumferential surface of the inner member, and the inner circumferential edge of the base is provided with an action piece that extends radially inward and inclined to one side in the axial direction, with the inner surface of the extended end in close contact with the outer circumferential surface of the inner member. In a torque limiter in which multiple braking torque applying means are arranged in a stacked manner in the axial direction, The inner periphery of the base is further provided with a support piece extending axially beyond the work piece to one side in the axial direction and a receiving piece extending radially inward, at a circumferential position where the work piece is not provided. In the axial direction adjacent The two braking torque applying means The receiving piece of the braking torque applying means located on one side in the axial direction is connected to the support piece of the braking torque applying means located on the other side in the axial direction. Aligned in the circumferential direction location A torque limiter characterized by the above is provided. 【0008】 Preferably, the braking torque applying means is in the shape of a thin plate ring. The working piece, the support piece, and the receiving piece are each provided in multiple quantities at equal angular intervals in the circumferential direction. In this case, it is preferable that the support piece and the receiving piece are arranged adjacent to each other in the circumferential direction. Preferably, the outer peripheral edge of the base is provided with the axial direction one side A cylindrical reinforcing wall is provided that extends radially outward after extending in a certain direction. 【0009】 According to a second aspect of the present invention, the present invention comprises an inner member that is rotatable relative to a common central axis and an outer member that houses at least a portion of the inner member, and a braking torque applying means that engages with the inner member, is non-rotatable relative to the inner member, and applies a required braking torque to the relative rotation, The braking torque applying means comprises an annular base whose outer surface faces the cylindrical inner surface of the outer member, and an acting piece is provided on the outer edge of the base that extends radially outward and inclined to one side in the axial direction, with the outer surface of the extended end in close contact with the inner surface of the outer member. In a torque limiter in which multiple braking torque applying means are arranged in a stacked manner in the axial direction, The outer periphery of the base is further provided with a support piece extending axially beyond the work piece to one side in the axial direction and a receiving piece extending radially outward, at a circumferential position where the work piece is not provided. In the axial direction adjacent The two braking torque applying means The receiving piece of the braking torque applying means located on one side in the axial direction is connected to the support piece of the braking torque applying means located on the other side in the axial direction. Aligned in the circumferential direction location A torque limiter characterized by the above is provided. [Effects of the Invention] 【0010】 According to the torque limiter of the present invention, at a circumferential position on the inner peripheral edge of the base of the braking torque applying means where no working piece is provided, a support piece extending axially beyond the working piece to one side in the axial direction and a receiving piece extending radially inward are provided, and further, in the axial direction The receiving piece of the braking torque applying means located on one side in the axial direction of two adjacent braking torque applying means is positioned in alignment in the circumferential direction with the supporting piece of the braking torque applying means located on the other side in the axial direction. Therefore, even if the braking torque applying means is excessively pressed into the inner or outer member, or if the braking torque applying means is arranged at an inclination with respect to the axial direction, the support piece of one of the two braking torque applying means arranged stacked in the axial direction will contact the receiving piece of the other braking torque applying means, thereby sufficiently and reliably preventing interference between the working piece of one braking torque applying means and the other braking torque applying means. For this reason, according to the torque limiter of the present invention, the magnitude of the braking torque provided by the braking torque applying means is stabilized. [Brief explanation of the drawing] 【0011】 [Figure 1] A diagram showing the overall configuration of a preferred embodiment of a torque limiter configured according to the present invention. [Figure 2] Figure 1 shows a diagram illustrating the inner component of the torque limiter. [Figure 3] Figure 1 shows a diagram illustrating the outer component of the torque limiter. [Figure 4] Figure 1 shows a standalone diagram of the braking torque application mechanism in the torque limiter. [Figure 5-1] Figure 1 shows the torque limiter with the shielding member removed (left side view). [Figure 5-2] Cross-sectional views shown by each cutting line shown in FIG. 5-1. [Figure 6] A diagram schematically showing a state in which the inner peripheral surface of the laminated braking torque applying means in the torque limiter shown in FIG. 1 is developed. 【Mode for Carrying Out the Invention】 【0012】 Hereinafter, a preferred embodiment of a torque limiter configured according to the present invention will be described in more detail with reference to the accompanying drawings. In the following description, “one side” and “the other side” in the axial direction are based on the state shown in the cross-sectional view A-A of FIG. 1, and the left side in the figure is “one side” and the right side is “the other side” unless otherwise specified. 【0013】 Referring to FIG. 1 for explanation, a torque limiter indicated by the number 2 as a whole includes an inner member 4, an outer member 6, and a braking torque applying means 8. 【0014】 Referring to FIG. 2 together with FIG. 1 for explanation, the inner member 4 is a cylindrical member made of metal and penetrates in the axial direction, and has a cylindrical outer peripheral surface 10. A pair of substantially rectangular recesses 12 are formed on both sides in the diameter direction at the inner peripheral edge of one axial side surface of the inner member 4, and through this pair of recesses 12, the inner member 4 is connected to one of the driving side and the driven side external devices (not shown) in a non-rotatable state relative to each other. 【0015】 Referring to Figure 3 in conjunction with Figure 1, the outer member 6 is formed by combining the main body 14 shown in Figure 3(a) and the shield body 16 shown in Figure 3(b), and both the main body 14 and the shield body 16 can be molded from appropriate synthetic resins. Referring mainly to Figure 3(a), the main body 14 comprises an annular end plate 18 arranged perpendicular to the axial direction and a cylindrical outer wall 20 extending from the outer peripheral edge of the end plate 18 to one side in the axial direction. A cylindrical connecting portion 24 is provided on the other side of the end plate 18 in the axial direction, surrounding the inner peripheral edge and extending to the other side in the axial direction. A pair of flat surfaces 26, which are parallel to each other when viewed from the axial direction, are formed on the outer peripheral surface of the connecting portion 24, and the outer member 6 is connected to the other external device (not shown), either the driving side or the driven side, in a state where relative rotation is not possible via this pair of flat surfaces 26. A recess 28 is formed on one side of the end plate 18 in the axial direction. The recess 28 has an annular portion 28a that extends circumferentially along the inner edge of one axial side surface of the end plate 18, and four radial portions 28b that extend radially outward from the annular portion 28a. The four radial portions 28b are arranged at equal angular intervals in the circumferential direction and are connected to the inner surface of the outer peripheral wall 20. 【0016】 Multiple (12 in the illustrated embodiment) roughly rectangular parallelepiped-shaped engaging protrusions 30 are arranged on the inner circumferential surface of the outer circumferential wall 20 at equal angular intervals in the circumferential direction. These protrusions project radially inward and extend linearly in the axial direction from one axial side to one axial end of the end plate 18. Engaging recesses 31 are defined between two adjacent engaging protrusions 30 in the circumferential direction. Consequently, multiple (12 in the illustrated embodiment) engaging recesses 31 are also arranged at equal angular intervals in the circumferential direction. Viewed from the axial direction, the radial portion 28b of the aforementioned recess 28 is connected to the inner surface of the outer circumferential wall 20 via the engaging recesses 31. Four axial locking protrusions 32 projecting radially inward are formed at equal angular intervals in the circumferential direction at one axial end of the inner circumferential surface of the outer circumferential wall 20. Viewed from the axial direction, the axial locking projection 32 aligns with the radial portion 28b of the recess 28 in the circumferential direction, and as shown in the AA cross-sectional view of Figure 3(a), the axial locking projection 32 is positioned to one side of the engaging ridge 30 in the axial direction. A single circumferential locking projection 34 projecting radially inward is also formed at one axial end of the inner circumferential surface of the outer peripheral wall 20. The circumferential locking projection 34 is also connected to one axial end face of the engaging ridge 30. 【0017】 Referring mainly to Figure 3(b), the shield body 16 is generally a thin, annular shape, and its outer surface is provided with circumferential locking recesses 36, which are locally formed notches. On one axial side of the outer surface of the shield body 16, except for the portion where the circumferential locking recesses 36 are formed, a chamfered portion 38 is formed that has a longitudinal cross-section arc shape and extends in the circumferential direction. On the outer edge of the other axial side of the shield body 16, multiple recesses 40 corresponding to the cross-sectional shape of the engagement protrusions 30 of the main body 14 are formed at equal angular intervals in the circumferential direction, more specifically the same number as the number of engagement protrusions 30 formed on the main body 14 (12 in the illustrated embodiment). On the inner edge of the other axial side of the shield body 16, an annular recess 41 extending in the circumferential direction is formed. 【0018】 Such a shield body 16 is assembled to the main body 14 by forcing it axially relative to the main body 14. Specifically, first the shield body 16 is positioned on one side of the main body 14 in the axial direction. At this time, the circumferential position of the circumferential locking recess 36 of the shield body 16 and the circumferential locking projection 34 of the main body 14 are aligned. Next, the shield body 16 is forced axially to the other side relative to the main body 14. In this way, the outer edge of the shield body 16 elastically overcomes the axial locking projection 32 of the main body 14, and the chamfered portion 38 faces the axial locking projection 32, and the shield body 16 is locked to the main body 14 in the axial direction. Furthermore, the circumferential locking projection 34 of the main body 14 fits into the circumferential locking recess 36 of the shield body 16, and one axial end of the engaging projection 30 of the main body 14 fits into the recess 40 of the shield body 16, thereby locking the shield body 16 to the main body 14 in the circumferential direction. Thus, the shield body 16 is assembled to the main body 14. 【0019】 The outer member 6 accommodates at least a portion of the inner member 4, and the outer member 6 and the inner member 4 are rotatable relative to each other around a common central axis o. As shown in the cross-sectional view AA of Figure 1, in the illustrated embodiment, the outer member 6 accommodates the entire inner member 4, with one axial end of the inner member 4 fitted into the recess 41 of the shield body 16, and the other axial end of the inner member 4 fitted into the annular portion 28a of the recess 28 of the main body 14, so that the inner member 4 is held rotatably relative to the outer member 6. 【0020】 In the illustrated embodiment, the braking torque applying means 8 is engaged with the outer member 6 and is non-rotatable relative to the outer member 6, applying the required braking torque to the relative rotation. Continuing the explanation with reference to Figure 4 along with Figure 1, in the illustrated embodiment, the braking torque applying means 8 is thin plate ring-shaped. The braking torque applying means 8 is made of metal and has an annular base 42 whose inner circumferential surface faces the outer circumferential surface 10 of the inner member 4. The base 42 is thin plate ring-shaped, and the inner circumferential edge of the base 42 has axial directions radially inward. On one sideMultiple inclined working pieces 44 are provided at intervals in the circumferential direction. In the illustrated embodiment, six working pieces 44 are provided, each denoted by reference numerals 44b to 44g. The inclination angle with respect to the axial direction and the extension length from the base 42 of the working pieces 44b to 44g are different, and the extension lengths are in the order of 44b, 44d, 44f, 44e, 44c, and 44g, with the length being longer in that order. The arrangement of the working pieces 44b to 44g will be described later. In a preferred embodiment of the present invention, the inner circumferential edge of the base 42 is further provided with working pieces 44 at circumferential positions where no working pieces 44 are provided, extending axially beyond the working pieces 44 in the axial direction On one side An extending support piece 46 and a receiving piece 48 extending radially inward are also provided. In the illustrated embodiment, there are three of each of the support piece 46 and the receiving piece 48, and the working piece 44, support piece 46 and receiving piece 48 are each arranged at equal angular intervals in the circumferential direction. As shown in Figure 6, for example, in the braking torque applying means indicated by reference numeral 8-1 in the figure, they are arranged in the order of working piece 44b, support piece 46, receiving piece 48, working piece 44e, working piece 44f, support piece 46, receiving piece 48, working piece 44c, working piece 44d, support piece 46, receiving piece 48, working piece 44g from the bottom to the top of the paper in the figure (when comparing and referring to Figures 4, 5-1 and 5-2 with Figure 6, note that the top and bottom of the paper for the FF and GG sections and the top and bottom of the paper for the BB to EE sections are reversed in Figures 4, 5-1 and 5-2). In other words, a pair of working pieces 44 and 44, and a pair of support pieces 46 and receiving pieces 48, which are arranged adjacently in the circumferential direction, are alternately arranged in the circumferential direction. The pair of working pieces 44 and 44 are composed of a combination of a relatively short and a relatively long working piece, and therefore the shortest working piece 44b and the longest working piece 44g, the second shortest working piece 44d and the second longest working piece 44c, and the third shortest working piece 44f and the third longest working piece 44e are arranged adjacently in the circumferential direction. As a result, when the braking torque applying means 8 is press-fitted into the inner member 4 and combined with it, as will be described later, the press-fit load is distributed in the circumferential direction, and the rotation of the inner member 4 relative to the braking torque applying means 8 is stabilized. The pair of support pieces 46 and receiving pieces 48 are also arranged adjacently in the circumferential direction. 【0021】 The outer periphery of the base 42 has an axial direction On one side A cylindrical reinforcing wall 50 is provided that extends radially outward after the initial extension. The height of the reinforcing wall 50, i.e., its axial width, is equal to the height of the support piece 46, i.e., the axial extension length from the base 42. Twelve engaging pieces 52 are arranged at equal angular intervals in the circumferential direction on the outer surface of the radially extending annular portion of the reinforcing wall 50, projecting radially outward. Viewed from the axial direction, the engaging pieces 52 are approximately rectangular in shape, and the circumferential width of the engaging pieces 52 corresponds to the circumferential width of the engaging recess 31 defined on the inner circumferential surface of the main body 14 of the outer member 6, i.e., it is the same as or slightly narrower than this. A notch 54 used for positioning is formed on the outer surface of one of the twelve engaging pieces 52. 【0022】 The braking torque applying means 8 is press-fitted into the inner member 4 and assembled with it either before or after the inner member 4 is assembled with the outer member 6, so that the inner surface of the extended end of the working piece 44 is in close contact with the outer circumferential surface 10 of the inner member 4. In the illustrated embodiment, as can be understood by referring to Figures 5-1, 5-2 and 6, because the inclination angles with respect to the axial direction and the extension lengths from the base 42 of the multiple working pieces 44 are different, the inner surfaces of the multiple working pieces 44 are in close contact with the outer circumferential surface 10 of the inner member 4 at different positions in the axial direction. In the illustrated embodiment, the support piece 46 and the receiving piece 48 do not abut the outer circumferential surface 10 of the inner member 4, but are separated from it. A lubricant such as grease is applied between the braking torque applying means 8 and the inner member 4. 【0023】 The braking torque applying means 8 further combines with the outer member 6 in a state where relative rotation around the common central axis o is impossible by fitting the engaging piece 52 into the aforementioned engaging recess 31 (of the outer member 6). As a result, when the inner member 4 and the outer member 6 rotate relative to each other around the common central axis o, the braking torque applying means 8 can apply the required braking torque to the relative rotation between the inner member 4 and the outer member 6 due to the close connection. 【0024】 In a preferred embodiment of the present invention, a plurality of braking torque applying means 8 are arranged in an axial stack. In the illustrated embodiment, three braking torque applying means 8 are provided, each denoted by reference numerals 8-1 to 8-3. As can be understood by referring to Figures 5-1, 5-2 and 6, the three braking torque applying means 8-1 to 8-3 are each combined with the outer member 6 with a phase difference of one position relative to it, so that one support piece 46 and the other receiving piece 48 of two braking torque applying means 8 (i.e., braking torque applying means 8-1 and 8-2, 8-2 and 8-3) arranged in an axial stack are aligned in the circumferential direction. By fitting the engaging piece 52 of the braking torque applying means 8 into the engaging recess 31 of the outer member 6, the braking torque applying means 8 and the outer member 6 are combined. Since both the engaging piece 52 and the engaging recess 31 are provided in multiples (12 each in the illustrated embodiment) at equal angular intervals in the circumferential direction, the phases of the three braking torque applying means 8-1 to 8-3 with respect to the outer member 6 can be shifted by one in the circumferential direction by shifting the engaging recess 31 into which the same engaging piece 52 is fitted by one. 【0025】 When an external device connected to the inner member 4 and the outer member 6 applies a rotational torque that causes them to rotate relative to each other around the central axis o, rotation is transmitted if this rotational torque is greater than the braking torque, while rotation is not transmitted if it is less than or equal to the braking torque. 【0026】 Here, according to the torque limiter 2, a preferred embodiment of the present invention, at a circumferential position on the inner peripheral edge of the base 42 of the braking torque applying means 8 where the working piece 44 is not provided, a support piece 46 extending axially to one side beyond the working piece 44 in the axial direction and a receiving piece 48 extending radially inward are provided, and further, in the axial direction The receiving piece 48 of the braking torque applying means 8 located on one side in the axial direction of two adjacent braking torque applying means 8 is positioned in alignment in the circumferential direction with the support piece 46 of the braking torque applying means 8 located on the other side in the axial direction.Therefore, even if the braking torque applying means 8 is excessively pressed into the inner member 4, or if the braking torque applying means 8 is arranged at an inclination with respect to the axial direction, the support piece 46 of one of the two braking torque applying means 8s, which are stacked in the axial direction, will contact the receiving piece 48 of the other braking torque applying means 8, thereby sufficiently and reliably preventing interference between the working piece 44 of one braking torque applying means 8 and the other braking torque applying means 8. For this reason, according to the torque limiter 2, which is a preferred embodiment of the present invention, the magnitude of the braking torque provided by the braking torque applying means 8 is stabilized. 【0027】 Although the torque limiter configured according to the present invention has been described in detail above with reference to the attached drawings, the present invention is not limited to the embodiments described above, and appropriate modifications and changes can be made without departing from the present invention. For example, in the illustrated embodiment, the outer member 6 is provided with an engagement recess 31, and the braking torque applying means 8 and the outer member 6 are assembled in a state where they cannot rotate relative to each other. However, if desired, the inner member may be provided with an engagement recess, and the braking torque applying means and the inner member may be assembled in a state where they cannot rotate relative to each other. In that case, the braking torque applying means comprises an annular base whose outer peripheral surface faces the cylindrical inner peripheral surface of the outer member, and the outer peripheral edge of the base has an axial direction toward the radially outward direction one side Multiple working pieces are provided at intervals in the circumferential direction, with the outer surface of the extended end in close contact with the inner circumferential surface of the outer member, and extending inclined in that direction. Furthermore, at the outer circumferential edge of the base, in a position where no working pieces are provided, there are additional working pieces extending axially beyond the working pieces in the axial direction. one side Support pieces extending in the direction and receiving pieces extending radially inward and outward are provided, and one support piece and the other receiving piece of the two braking torque applying means, which are stacked in the axial direction, are aligned in the circumferential direction. The material of each component can be changed as appropriate. [Explanation of Symbols] 【0028】 2: Torque limiter 4: Inner components 6:Outer member 8: Braking torque application means 10: Outer surface (of the inner member) 42: Base 44: Working piece 46: Support piece 48: Receiver

Claims

[Claim 1] It comprises an inner member that is rotatable relative to a common central axis and an outer member that houses at least a portion of the inner member, and a braking torque applying means that engages with the outer member, is non-rotatable relative to the outer member, and applies a required braking torque to the relative rotation, The braking torque applying means comprises an annular base whose inner circumferential surface faces the cylindrical outer circumferential surface of the inner member, and the inner circumferential edge of the base is provided with an action piece that extends radially inward and inclined to one side in the axial direction, with the inner surface of the extended end in close contact with the outer circumferential surface of the inner member. In a torque limiter in which multiple braking torque applying means are arranged in a stacked manner in the axial direction, The inner periphery of the base is further provided with a support piece extending axially beyond the work piece to one side in the axial direction and a receiving piece extending radially inward, at a circumferential position where the work piece is not provided. A torque limiter characterized in that, of two axially adjacent braking torque applying means, the receiving piece of the braking torque applying means located on one side in the axial direction is positioned in alignment in the circumferential direction with the support piece of the braking torque applying means located on the other side in the axial direction. [Claim 2] The torque limiter according to claim 1, wherein the braking torque applying means is in the shape of a thin plate ring. [Claim 3] The torque limiter according to claim 1, wherein the working piece, the support piece, and the receiving piece are each provided in multiple quantities at equal angular intervals in the circumferential direction. [Claim 4] The torque limiter according to claim 3, wherein the support piece and the receiving piece are arranged adjacent to each other in the circumferential direction. [Claim 5] The torque limiter according to claim 1, wherein a cylindrical reinforcing wall is provided on the outer peripheral edge of the base, extending axially to one side and then radially outward. [Claim 6] It comprises an inner member that is rotatable relative to a common central axis and an outer member that houses at least a portion of the inner member, and a braking torque applying means that engages with the inner member, is non-rotatable relative to the inner member, and applies a required braking torque to the relative rotation, The braking torque applying means comprises an annular base whose outer surface faces the cylindrical inner surface of the outer member, and an acting piece is provided on the outer edge of the base that extends radially outward and inclined to one side in the axial direction, with the outer surface of the extended end in close contact with the inner surface of the outer member. In a torque limiter in which multiple braking torque applying means are arranged in a stacked manner in the axial direction, The outer periphery of the base is further provided with a support piece extending axially beyond the work piece to one side in the axial direction and a receiving piece extending radially outward, at a circumferential position where the work piece is not provided. A torque limiter characterized in that, of two axially adjacent braking torque applying means, the receiving piece of the braking torque applying means located on one side in the axial direction is positioned in alignment in the circumferential direction with the support piece of the braking torque applying means located on the other side in the axial direction.

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