Abstract:
This tolerance ring, which is for a torque transmission device, preferably has a ring body that comprises an elastic plate and is roughly a hollow cylindrical shape having a pair of edges that extend in the axial direction. The ring body has: a plurality of protrusions that are arranged along the peripheral direction and preferably protrude in the radial direction; a first region having a number of the protrusions including the pair of protrusions adjacent to the pair of edges; and that is positioned at the diametrically opposite side from the first region. The pair of protrusions has the same rigidity as one of the protrusions of the second region.

Description:
PRIORITY CLAIM 
       [0001]    The present application is a National Phase entry of PCT Application No. PCT/JP2011/069742, filed Aug. 31, 2011, which claims priority from Japanese Patent Application No. 2010-197573, filed Sep. 3, 2010, the disclosures of which are hereby incorporated by reference herein in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to tolerance rings for torque transmission devices. 
       DESCRIPTION OF THE RELATED ART 
       [0003]    A conventional example will be described.  FIG. 26  is a cross-sectional view of a conventional torque transmission device. As shown in  FIG. 26 , the torque transmission device T has an inner axial member S 1 , an outer axial member S 2 , which are placed concentrically, and a tolerance ring  10  fitted in an annular space between the axial members S 1  and S 2 . The inner axial member S 1  has an outer peripheral surface S 1   a  in a hollow cylinder shape having a predetermined outside diameter. Also, the outer axial member S 2  has an inner peripheral surface S 2   a  in a hollow cylinder shape having a larger inside diameter than the outside diameter of the outer peripheral surface S 1   a  of the inner axial member S 1 . The tolerance ring  10  works as a torque limiter for allowing relative rotation between the axial members S 1  and S 2  such that when an input torque is lower than a predetermined torque, the axial members S 1  and S 2  rotate together. When the input torque is higher than the predetermined torque, the axial members S 1  and S 2  slide against each other. A tolerance ring working as torque limiter is described in, for example, Japanese Laid-Open Patent Publication No. 2002-308119. 
         [0004]    One example of the tolerance ring  10  used in the torque transmission device T will be described.  FIG. 27  is a perspective view showing a tolerance ring.  FIG. 28  is a side view along an axial direction.  FIG. 29  is a top view of a developed tolerance ring.  FIG. 30  is a cross-sectional view along line XXX-XXX in  FIG. 29 .  FIG. 31  is a cross-sectional view along line XXXI-XXXI in  FIG. 29 . 
         [0005]    As shown in  FIGS. 27 and 28 , the tolerance ring  10  consists of a ring body  11  having a spring behavior and being shaped in a hollow cylinder shape with a gap between both edges in a circumferential direction. The ring body  11  has a plurality of protrusions  13  projecting outward in a radial direction and being placed at regular intervals in the circumferential direction. For example, the number of the protrusions  13  is twenty-eight in the circumferential direction and they are arranged in two lines in the axial direction. Since the lines of the protrusions  13  are symmetrically positioned about a plane vertical to the axis of the tolerance ring  10 , one line will be described, while explanation of the other line will be omitted. The tolerance ring  10  that is developed in a plate shape (i.e., intermediate product before forming in a cylinder shape) is referred to as protrusions-provided plate  10 A (see  FIGS. 29-31 ). The tolerance ring  10  is made by bending the protrusions-provided plate  10 A in a cylinder shape. The tolerance ring  10  is preferably made of metal materials, and may be made of resin materials. 
         [0006]    The protrusions  13  have the same configuration and are placed regularly and continuously in the circumferential direction. Each of the protrusions  13  is formed in a hipped roof shape (see  FIG. 27 ) having a triangular cross-section (see  FIG. 30 ), a predetermined length  13 L in the axial direction (see  FIGS. 29 and 31 ), a predetermined width  13 W in the peripheral direction (see  FIGS. 29 and 30 ), and a predetermined height  13 H projecting in the radial direction (see  FIGS. 30 and 31 ). That is, each of the protrusions  13  consists of two triangular slopes and two trapezoidal slopes such that upper sides of the trapezoidal slopes together form a ridge line  13   a  and lower sides of four slopes together form a rectangle. Each of the protrusions  13  is symmetrically formed in a longitudinal direction (vertical direction in  FIG. 29 ) and a width direction (horizontal direction in  FIG. 29 ). In the ring body  11 , in areas other than the protrusions  13 , i.e., an axially central area  14 , axially end areas  15  and peripherally edge areas  16  (see  FIG. 29 ) are positioned on the same cylinder surface (see  FIG. 27 ). The opposed edge areas  16  together form a gap  12  therebetween ( FIG. 27 ). In each edge area  16 , a portion between the protrusion  13  and the gap  12  is referred to as edge portion  16   a.    
         [0007]    As shown in  FIG. 26 , the tolerance ring  10  is fitted between the axial members  51  and S 2  of the torque transmission device T. In this operation, the ring body  11  is expanded to be closely-attached to the outer peripheral surface S 1   a  of the inner axial member S 1 . Accordingly, the width of the gap  12  of the attached ring body  11  is wider than that of the gap  12  of the non-attached ring body  11  (see  FIG. 28 ). The ridge line  13   a  of each protrusion  13  elastically contacts with the inner peripheral surface S 2   a  of the outer axial member S 2 . 
         [0008]    In the tolerance ring  10 , a pair of edge areas  16  adjacent to the gap  12  (right-left pair in  FIG. 28 ) of the ring body  11  is in a cantilever spring state, respectively. Thus, the edge portions  16   a  between the gap  12  and each of the protrusions  13  close to the gap  12  (see  FIG. 27 ) have low rigidity and can be easily deformed. As a result, the protrusions  13  near the gap  12  (corresponding to about one to three protrusion(s)  13  in each edge area  16 ) are likely to decrease their rigidities. In a situation where such a tolerance ring  10  is used in the torque transmission device T (see  FIG. 26 ), there is a fear that the protrusions  13  near the gap  12  could easily collapse, so that the axial members S 1  and S 2  become eccentric. That is, in  FIG. 26 , when the axis of the outer axial member S 2  moves downwardly relative to the axis of the inner axial member S 1 , a space between the axial members S 1  and S 2  becomes narrow near the gap  12  (upper end in  FIG. 26 ), while another space between the axial members S 1  and S 2  at an area opposing to the gap  12  in the radial direction (lower end in  FIG. 26 ) becomes broad. In this way, eccentricity between the axial members S 1  and S 2  is undesirable since it causes an increase in slip torque in one area in the circumferential direction and causes a decrease in slip torque in another area, and thus makes surface pressure remarkably unevenness and leads to positional displacement of the inner axial member S 1  and/or the outer axial member S 2 . 
         [0009]    Accordingly, there has been need for tolerance rings for torque transmission devices, which can prevent eccentricity between the axial members of the torque transmission devices. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    One aspect of this disclosure is a torque transmitting tolerance ring having a ring body that is made of an elastic plate and is formed in a substantially hollow cylinder shape having a pair of edges extending in an axial direction. The ring body has a plurality of protrusions radially projecting and being aligned along a peripheral direction. It may have a first region having some of the protrusions including a pair of the protrusions adjacent to the pair of the edges. It may have a second region being positioned on an opposite side to the first region in a diametrical direction and having some of the protrusions. Preferably the pair of the protrusions have equal rigidity to one of the protrusions in the second region. 
         [0011]    In accordance with the aspect, since rigidities of the protrusions balance in the diametrical direction through a gap formed between the pair of the edges, collapse of the pair of the protrusions can be prevented so that it is able to prevent eccentricity between the axial members of the torque transmission device. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0012]      FIG. 1  is a cross-sectional view showing a torque transmission device of a first embodiment; 
           [0013]      FIG. 2  is a perspective view of a tolerance ring; 
           [0014]      FIG. 3  is a top view of a developed tolerance ring; 
           [0015]      FIG. 4  is a cross-sectional view along line IV-IV in  FIG. 3 ; 
           [0016]      FIG. 5  is a cross-sectional view of the torque transmission device of a second embodiment; 
           [0017]      FIG. 6  is a cross-sectional view of the torque transmission device of a third embodiment; 
           [0018]      FIG. 7  is a cross-sectional view of the torque transmission device of a fourth embodiment; 
           [0019]      FIG. 8  is a top view of the developed tolerance ring; 
           [0020]      FIG. 9  is a cross-sectional view along line IX-IX in  FIG. 8 ; 
           [0021]      FIG. 10  is a top view of the developed tolerance ring of a fifth embodiment; 
           [0022]      FIG. 11  is a cross-sectional view along line XI-XI in  FIG. 10 ; 
           [0023]      FIG. 12  is a top view of the developed tolerance ring of a sixth embodiment; 
           [0024]      FIG. 13  is a cross-sectional view along line XIII-XIII in  FIG. 12 ; 
           [0025]      FIG. 14  is a top view of the developed tolerance ring of a seventh embodiment; 
           [0026]      FIG. 15  is a cross-sectional view along line XV-XV in  FIG. 14 ; 
           [0027]      FIG. 16  is a cross-sectional view along line XVI-XVI in  FIG. 14 ; 
           [0028]      FIG. 17  is a cross-sectional view of the torque transmission device of an eighth embodiment; 
           [0029]      FIG. 18  is a side view showing a significant portion of the tolerance ring; 
           [0030]      FIG. 19  is a cross-sectional view of the torque transmission device of a ninth embodiment; 
           [0031]      FIG. 20  is a cross-sectional view of the torque transmission device of a tenth embodiment; 
           [0032]      FIG. 21  is a cross-sectional view of the torque transmission device of an eleventh embodiment; 
           [0033]      FIG. 22  is a cross-sectional view of the torque transmission device of a twelfth embodiment; 
           [0034]      FIG. 23  is a cross-sectional view of the torque transmission device of a thirteenth embodiment; 
           [0035]      FIG. 24  is a bottom view of the tolerance ring; 
           [0036]      FIG. 25  is a cross-sectional view of a variant of the torque transmission device of the first embodiment; 
           [0037]      FIG. 26  is a cross-sectional view of a conventional torque transmission device; 
           [0038]      FIG. 27  is a perspective view of a tolerance ring; 
           [0039]      FIG. 28  is a side view of the tolerance ring in an axial direction; 
           [0040]      FIG. 29  is a top view of the developed tolerance ring; 
           [0041]      FIG. 30  is a cross-sectional view along line XXX-XXX in  FIG. 29 ; and 
           [0042]      FIG. 31  is a cross-sectional view along line XXXI-XXXI in  FIG. 29 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0043]    Each embodiment will be described in reference to drawings hereafter. Because the tolerance ring of each embodiment is based on the conventional example (see  FIGS. 26-31 ) and is provided with some changes, such changes will be described, while overlapping explanations will be omitted. For convenience of explanation, the protrusion  13  is used as a basic shape, so the protrusion  13  is referred to as “standard protrusion  13 ”. 
         [0044]    A first embodiment will be described.  FIG. 1  is a cross-sectional view showing a torque transmission device.  FIG. 2  is a perspective view of the tolerance ring.  FIG. 3  is a top view of the developed same tolerance ring.  FIG. 4  is a cross-sectional view along line IV-IV in  FIG. 3 . 
         [0045]    With respect to a tolerance ring  10  used for a torque transmission device of this embodiment, one and a half of reinforced protrusions  131  and  132  are formed at each edge area  16  of the ring body  11  symmetrically about the gap  12 . The reinforced protrusion  131  has a narrower width  131 W (see  FIGS. 3 and 4 ) than the width  13 W of the standard protrusions  13  (see  FIGS. 29 and 30 ). Because of this configuration, rigidities of the reinforced protrusions  131  are higher than those of the standard protrusions  13 . In addition, the reinforced protrusions  131  each have the same length  13 L with the length  13 L of the standard protrusions  13  (see  FIGS. 29 and 31 ). Moreover, the reinforced protrusions  131  each have the same height  13 H with the height  13 H of the standard protrusions  13  (see  FIGS. 30 and 31 ). Each of the reinforced protrusions  131  is continuously formed with the standard protrusion  13 , which is adjacent to the reinforced protrusion  131 , and the reinforced protrusion  132  (see  FIGS. 3 and 4 ). Here, the reinforced protrusions  132  make rigidities of the edge portions  16   a  higher, and thus are referred to as edge reinforcing portions  132 . 
         [0046]    Each of the edge reinforcing portions  132  is formed to be a half of the reinforced protrusion  131  in the width direction (horizontal direction in  FIG. 3 ), and is placed at the edge portion  16   a  adjacent to the reinforced protrusion  131  in each edge area  16 . A ridge line  132   a  of the each edge reinforcing portion  132  (see  FIG. 3 ) is positioned at an edge of the each edge area  16  in the circumferential direction. Formation of the edge reinforcing portions  132  makes the edge portions  16   a  (including the edge reinforcing portions  132 ) near the gap  12  of the ring body  11  concave-convex shape in the axial direction (vertical direction in  FIG. 3 ) thereby increasing rigidities of them. Accordingly, rigidities of the pair of the reinforced protrusions  131  are increased. 
         [0047]    The number of the standard protrusions  13  is reduced from twenty-eight of the conventional art (see  FIG. 28 ) to eighteen. Between standard protrusions  13  close to each other, circumferentially even areas  17  (see  FIGS. 2 and 3 ) are formed to be positioned on the same cylinder surface with the axially central area  14  and the both end areas  15  of the ring body  11 . In a situation where the tolerance ring  10  is fitted between the axial members S 1  and S 2  of the torque transmission device T (see  FIG. 1 ), which is referred to as “fitted state”, the eighteen standard protrusions  13  are arranged at regular intervals in the circumferential direction of the ring body  11  and opposed to one another in the radial direction of the ring body  11  (are positioned on a line  13 D extending in the diametrical direction). In a cross-sectional view vertical to the axis of the ring body  11 , the standard protrusions  13  are positioned in a symmetric manner about a line  11 L diametrically extending through a center of the gap  12  of the ring body  11  (bilaterally symmetric in  FIG. 1 ). 
         [0048]    Due to increase in the rigidities of the reinforced protrusions  131  of the ring body  11  and increase in the rigidities of the edge portions  16   a  near the gap  12 , it is configured that the rigidity of the each reinforced protrusion  131  is equal to the rigidity of the standard protrusion  13  positioned at a half radially opposed to the gap  12  (lower half in  FIG. 1 ) of the ring body  11 . 
         [0049]    In accordance with the above-mentioned tolerance ring  10 , it is configured that each rigidity of the pair of the reinforced protrusions  131  of the ring body  11  is equal to the rigidity of the standard protrusion  13  placed at the half diametrically opposed to the gap  12  of the ring  11 . Accordingly, the rigidities of the protrusions (the standard protrusion  13  and the reinforced protrusion  131 ) balance in the diametrical direction extending through the gap  12  of the tolerance ring  10  (vertical direction in  FIG. 1 ), so it is able to prevent collapse of the pair of the reinforced protrusions  131 , and thus to prevent eccentric between the axial members S 1  and S 2  of the torque transmission device. Thus, it is able to prevent unevenness of surface pressure in the circumferential direction caused by the eccentric between the axial members S 1  and S 2 . It is further able to inhibit positional displacement of the inner axial member S 1  and/or the outer axial member S 2 . 
         [0050]    In addition to increase in the rigidities of the pair of the reinforced protrusions  131  of the ring body  11 , the edge portions  132  may be formed at the edge portions  16   a  adjacent to the pair of the reinforced protrusions  131 . This can increase the rigidities of the pair of the reinforced protrusions  131 . Thus, the rigidities of the pair of the reinforced protrusions  131  of the ring body  11  can be increased by reinforcement themselves and increase in the rigidities of the edge portions  16   a . Here, a plurality of the reinforced protrusions  131  may be formed at each edge area  16 . Each of the edge reinforcing portions  132  is not limited to a shape corresponding to a half of the reinforced protrusion  131 . They may be formed in any shape providing at least one radially concave or convex at the edge portion  16   a  near the gap  12 . 
         [0051]    In the fitted state of the tolerance ring  10  in the torque transmission device T (see  FIG. 1 ), the standard protrusions  13  are arranged at regular intervals in the circumferential direction of the ring body  11 . They may be arranged in an opposing manner to each other in the diametrical direction of the ring body  11  (in a manner positioned on the line  13 D extending in the diametrical direction). Hence, it is easy to balance the rigidities of the standard protrusions  13 . 
         [0052]    A second embodiment will be described. This embodiment corresponds to the first embodiment with some changes.  FIG. 5  is a cross-sectional view of the torque transmission device. 
         [0053]    As shown in  FIG. 5 , in the tolerance ring  10  of this embodiment, the reinforced protrusions  131  and the edge reinforcing portions  132  of the first embodiment (see  FIG. 1 ) are omitted, while each three reinforced protrusions  13 A,  13 B and  13 C are formed near the gap  12  of the ring body  11 . The reinforced protrusions  13 A,  13 B and  13 C are formed in the same shape with the standard protrusion  13  and are aligned along the circumferential direction from a gap  12  side toward the standard protrusion  13  side. On the ring body  11 , the axially central area  14 , the axially end areas  15  and the peripherally edge areas  16  (including edge portions  16   a ) are formed to be positioned on the same cylinder surface like in the conventional art (see  FIG. 26 ). 
         [0054]    The reinforced protrusions  13 A,  13 B and  13 C are placed such that intervals therebetween gradually become narrow from the standard protrusion  13  side toward the gap  12  side. In particular, a distance between the reinforced protrusions  13 A and  13 B is referred to as d 1 , a distance between the reinforced protrusions  13 B and  13 C is referred to as d 2 , a distance between the reinforced protrusions  13 C and the standard protrusion  13  is referred to as d 3 , and a distance between the standard protrusions  13  is referred to as d 4 . The distances d 1 , d 2  and d 3  are determined to satisfy the relationship as d 1 &lt;d 2 &lt;d 3 &lt;d 4 . Because of this configuration, the rigidities of the reinforced protrusions  13 A,  13 B and  13 C near the gap  12  of the ring body  11  are increased. 
         [0055]    The reinforced protrusions  13 A,  13 B and  13 C may be configured by at least two of them adjacent to each other. The standard protrusions  13  placed at the half diametrically opposed to the gap  12  of the ring body  11  may be positioned such that, for example, intervals between each three standard protrusions  13 , which are positioned at each sides of the line  11 L diametrically extending through the center of the gap  12  of the ring body  11 , gradually become wider toward the line  11 L in order to decrease in rigidities of the standard protrusions placed at the half diametrically opposed to the gap  12  of the ring body  11 . In this case, it is able to increase in rigidities of the pair of the protrusions  13  near the gap  12  of the ring body  11  relative to the standard protrusions  13  placed at the half diametrically opposed to the gap  12 . 
         [0056]    A third embodiment will be described. This embodiment corresponds to the first embodiment with some changes.  FIG. 6  is a cross-sectional view of the torque transmission device. 
         [0057]    As shown in  FIG. 6 , in the tolerance ring  10  of this embodiment, the reinforced protrusions  131  and the edge reinforcing portions  132  of the first embodiment (see  FIG. 1 ) are omitted, while two of the standard protrusions  13  are added such that total twenty standard protrusions  13  are formed. The twenty standard protrusions  13  are placed at regular intervals in the circumferential direction. The rigidities of the pair of the standard protrusions  13  close to the gap  12  of the ring body  11  are increased by surface treatment such as shot peening treatment or heat treatment. 
         [0058]    In accordance with this embodiment, since the total twenty standard protrusions  13  are placed at regular intervals in the circumferential direction, it is able to easily balance rigidities of the standard protrusions  13  over the entire circumference of the tolerance ring  10 . In this embodiment, at the edge areas  16  near the gap  12  of the ring body  11 , the standard protrusions  13  near the gap  12  are formed overlapping the edge portions  16   a . Meanwhile, the standard protrusions  13  may be placed adjacent to the edge portions  16   a  in the same manner with the conventional art (see  FIG. 26 ). The rigidities of the pair of the standard protrusions  13  near the gap  12  of the ring body  11  may be increased by the addition of reinforcing members, an increase in thickness or the like other than surface treatment. 
         [0059]    A fourth embodiment will be described. This embodiment corresponds to the conventional art with some changes.  FIG. 7  is a cross-sectional view of the torque transmission device.  FIG. 8  is a top view of the developed same tolerance ring  10 .  FIG. 9  is a cross-sectional view along line IX-IX in  FIG. 8 . 
         [0060]    As shown in  FIGS. 7-9 , the tolerance ring  10  of this embodiment certain features are formed in a similar manner as the first embodiment (see  FIGS. 1-4 ). At the pair of the edge areas  16  near the gap  12  of the ring body  11  of the conventional art (see  FIGS. 28-30 ) the reinforced protrusions  131  and the edge reinforcing portions  132  are formed symmetrically about the gap  12 . The number of the standard protrusions is reduced from twenty-eight in the conventional art (see  FIG. 28 ) to twenty-five. The twenty-five standard protrusions  13  are arranged regularly and continuously in a circumferential direction in the same way as the conventional art (see  FIGS. 29 and 30 ). 
         [0061]    A fifth embodiment will be described. This embodiment corresponds to the fourth embodiment with some changes.  FIG. 10  is a top view of the developed tolerance ring.  FIG. 11  is a cross-sectional view along line XI-XI in  FIG. 10 . 
         [0062]    As shown in  FIGS. 10 and 11 , in the tolerance ring  10  of this embodiment, the edge reinforcing portions  132  of the fourth embodiment (see  FIGS. 7-9 ) are omitted. As a result, the edge portions  16   a  are positioned on the same cylinder surface with the axially central area  14 . Also, the end areas  15  are formed at edge areas  16  close to the gap  12  of the ring body  11  in the same manner as the conventional art (see  FIGS. 29 and 30 ). 
         [0063]    A sixth embodiment will be described. This embodiment corresponds to the conventional art with some changes.  FIG. 12  is a top view of the developed tolerance ring.  FIG. 13  is a cross-sectional view along line XIII-XIII in  FIG. 12 . 
         [0064]    As shown in  FIGS. 12 and 13 , in the tolerance ring  10  of this embodiment, the pair of the standard protrusions  13  close to the gap  12  of the conventional art (see  FIGS. 26-31 ) are replaced with reinforced protrusions  133 . The reinforced protrusions  133  each have length  133 L longer than length  13 L of the standard protrusions  13  (see  FIGS. 29 and 31 ). Due to this configuration, rigidities of the reinforced protrusions  133  are increased compared to the rigidities of the standard protrusions  13 . The reinforced protrusions  133  are formed to have the width  13 W same with the width  13 W of the standard protrusions  13  (see  FIGS. 29 and 30 ). The reinforced protrusions  133  are formed to have the same height  13 H as the height  13 H of the standard protrusions  13  (see  FIGS. 30 and 31 ). 
         [0065]    A seventh embodiment will be described. This embodiment corresponds to the conventional art with some changes.  FIG. 14  is a top view of the developed tolerance ring.  FIG. 15  is a cross-sectional view along line XV-XV in  FIG. 14 .  FIG. 16  is a cross-sectional view along line XVI-XVI in  FIG. 14 . 
         [0066]    As shown in  FIGS. 14-16 , in the tolerance ring  10  of this embodiment, the pair of the standard protrusion  13  close to the gap  12  of the conventional art (see  FIGS. 26-31 ) are replaced with reinforced protrusions  134 . The reinforced protrusions  134  each have a height  134 H (see  FIGS. 15 and 16 ) that is higher than the height  13 H of the standard protrusions  13  (see  FIGS. 30 and 31 ). This makes rigidities of the reinforced protrusions  134  high compared with the rigidities of the standard protrusions  13 . The reinforced protrusions  134  are shaped to have the same length  13 L as the length  13 L of the standard protrusions  13  (see  FIGS. 29 and 31 ). The reinforced protrusions  134  are shaped to have the same width  13 W as the width  13 W of the standard protrusions  13  (see  FIGS. 29 and 30 ). 
         [0067]    An eighth embodiment will be described. This embodiment corresponds to the conventional art with some changes.  FIG. 17  is a cross-sectional view of the torque transmission device.  FIG. 18  is a side view of a part of the tolerance ring. 
         [0068]    As shown in  FIGS. 17 and 18 , in the tolerance ring  10  of this embodiment, the standard protrusion  13  positioned diametrically opposed to the gap  12  is replaced with a weakened protrusion  135 . The weakened protrusion  135  has a height  135 H (see  FIG. 18 ) lower than the height  13 H of the standard protrusions  13  (see  FIGS. 30 and 31 ). This makes the rigidity of the weakened protrusion  135  lower as compared to the rigidity of the standard protrusions  13 . Accordingly, in this embodiment, it is able to increase in the rigidities of the pair of the protrusions  13  close to the gap  12  of the ring body  11  relative to the rigidity of the weakened protrusion  135 . The weakened protrusion  135  is shaped to have the same length  13 L as the length  13 L of the standard protrusions  13  (see  FIGS. 29 and 31 ). The weakened protrusion  135  is shaped to have the same width  13 W as the width  13 W of the standard protrusions  13  (see  FIGS. 29 and 30 ). 
         [0069]    The total number including the weakened protrusion  135  and the standard protrusions  13  is set to twenty-seven such that the weakened protrusion  135  is positioned diametrically opposed to the gap  12  (positional relationship on the line  11 L extending in the diametrical direction). The twenty-six standard protrusions  13  are placed symmetrically about the line  11 L diametrically extending through the center of the gap  12  of the ring body  11  (in a right-left symmetric manner in  FIG. 17 ). 
         [0070]    A ninth embodiment will be described. This embodiment corresponds to the conventional art with some changes.  FIG. 19  is a cross-sectional view of the torque transmission device. 
         [0071]    As shown in  FIGS. 17 and 18 , in the tolerance ring  10  of this embodiment, the weakened protrusion  135  positioned diametrically opposed to the gap  12  of the ring body  11  of the eighth embodiment (see  FIGS. 17 and 18 ) is replaced with a standard protrusion  13 . Meanwhile with respect to the standard protrusions  13 , they are placed halfway diametrically opposed to the gap  12  (lower half in  FIG. 19 ), for example, a pair of the standard protrusions  13 , which are ninth from the gap  12  side (one pair in  FIG. 19 ), is replaced with weakened protrusions  135 . The weakened protrusions  135  are formed in the same shape with those of the eighth embodiment. It is only necessary to place the weakened protrusions  135  halfway diametrically opposed to the gap  12  (lower half in  FIG. 19 ) in a symmetric manner about the line  11 L (right-left symmetric manner in  FIG. 19 ). In this way, one or more of the weakened protrusions  135  may be used instead of one or more of the standard protrusions  13 . These are located seventh to twelfth from the gap  12  side. 
         [0072]    A tenth embodiment will be described. This embodiment corresponds to the eighth embodiment with some changes.  FIG. 20  is a cross-sectional view of the torque transmission device. 
         [0073]    As shown in  FIG. 20 , in the tolerance ring  10  of this embodiment, the weakened protrusion  135  of the eighth embodiment (see  FIG. 17 ) is omitted. An area where the weakened protrusion  135  is omitted is shaped as an even area  136  positioned on the same cylinder surface with the end areas  15  and the edge areas  16  of the ring body  11 . In this way, a distance between the adjacent standard protrusions  13  becomes wider at the even area  136 . 
         [0074]    An eleventh embodiment will be described. This embodiment corresponds to the ninth embodiment with some changes.  FIG. 21  is a cross-sectional view of the torque transmission device. 
         [0075]    As shown in  FIG. 21 , in the tolerance ring  10  of this embodiment, the pair (right-left pair in  FIG. 21 ) of the weakened protrusions  135  of the ninth embodiment (see  FIG. 19 ) is omitted. Areas where the weakened protrusions  135  are omitted are shaped as even areas  136  positioned on the same cylinder surface with the end areas  15  and the edge areas  16  of the ring body  11  in a similar way to the tenth embodiment ( FIG. 20 ), so that distances between the standard protrusions  13  become wider at each even area  136 . 
         [0076]    A twelfth embodiment will be described. This embodiment corresponds to the eighth embodiment with some changes.  FIG. 22  is a cross-sectional view of the torque transmission device. 
         [0077]    As shown in  FIG. 22 , in the tolerance ring  10  of this embodiment, the weakened protrusion  135  of the eighth embodiment ( FIG. 17 ) is replaced with a wide weakened protrusion  137 . The weakened protrusion  137  of this embodiment has a broader width  137 W than the width  13 W of the standard protrusions  13  (see  FIGS. 29 and 30 ). This makes the rigidity of the weakened protrusion  137  lower as compared to the rigidities of the standard protrusions  13 . The weakened protrusion  137  is shaped to have the same length  13 L as the length  13 L of the standard protrusions  13  (see  FIGS. 29 and 31 ). The weakened protrusion  137  is shaped to have the same height  13 H as the height  13 H of the standard protrusions  13  (see  FIGS. 30 and 31 ). Here, when the length  13 L of the standard protrusions  13  is shortened, a rigidity of a formed weakened protrusion  137  can be low. 
         [0078]    A thirteenth embodiment will be described. This embodiment corresponds to the tenth embodiment with some changes.  FIG. 23  is a cross-sectional view of the torque transmission device.  FIG. 24  is a bottom view of the tolerance ring. 
         [0079]    As shown in  FIGS. 23 and 24 , in the tolerance ring  10  of this embodiment, grooves  138  axially extending from axially end areas  15  toward a center area of the ring body  11  are formed at the even area  136  of the tenth embodiment (see  FIG. 20 ). Due to this configuration, since the rigidity of the even area  136  decreases, the rigidities of the pair of the standard protrusions  13  positioned at each side of the grooves  138  become low. The grooves  138  may be shaped as hole. In this embodiment, the standard protrusions  13  are shaped to have longer length  13 La in the axial direction (vertical direction in  FIG. 24 ). Furthermore, a number of the standard protrusions  13  are arranged in one line in the circumferential direction. 
         [0080]    This disclosure is not limited to the above-mentioned embodiments, and modifications can be made without departing from the substance of this disclosure. For example, means for increasing rigidity of the protrusion, and/or means for decreasing rigidity of the protrusion can be changed as necessary. The technical features of the embodiments may be used independently or in combination with each other. The shape of the protrusion (standard protrusion, reinforced protrusion, weakened protrusion) of the tolerance ring  10  may be changed as necessary. The protrusion (standard protrusion, reinforced protrusion, weakened protrusion) of the tolerance ring  10  is not limited to one projecting outwardly in the radial direction, and may project inwardly in the radial direction as shown in  FIG. 25 . Here, the torque transmission device shown in  FIG. 25  is a variant of the first embodiment, so corresponding components are labeled with the same symbols, respectively. The tolerance ring is mainly used for the torque transmission device, however it can be used to prevent backlash between an inner axial member and an outer axial member of a hinge device such as door. In addition, it is assumed that the tolerance ring is placed between an inner axial member and an outer axial member such that peripheral edge areas overlap in the radial direction. In this case, the peripheral edge areas may separate in the radial direction, and may contact with each other. 
       EXPLANATIONS OF NUMERALS 
       [0081]      10  tolerance ring 
         [0082]      11  ring body 
         [0083]      12  gap 
         [0084]      13  protrusion (standard protrusion) 
         [0085]      13 A,  13 B,  13 C reinforced protrusion 
         [0086]      14  central area 
         [0087]      15  end area 
         [0088]      16  edge area 
         [0089]      16   a  edge portion 
         [0090]      17  even area 
         [0091]      131  reinforced protrusion 
         [0092]      132  edge reinforcing portion (reinforced protrusion) 
         [0093]      133  reinforced protrusion 
         [0094]      134  reinforced protrusion 
         [0095]      135  weakened protrusion 
         [0096]      136  even area 
         [0097]      137  weakened protrusion 
         [0098]      138  groove 
         [0099]    S 1  inner axial member 
         [0100]    S 2  outer axial member 
         [0101]    T torque transmission device