WO2021091569A1

WO2021091569A1 - Damped belt tensioner

Info

Publication number: WO2021091569A1
Application number: PCT/US2019/060474
Authority: WO
Inventors: Shawn J. Blackmur
Original assignee: Borgwarner Inc.
Priority date: 2019-11-08
Filing date: 2019-11-08
Publication date: 2021-05-14

Abstract

A tensioner with an arm, a tensioner wheel, a tensioner element, a spring and a damping arrangement. The arm defines a pivot axis. The tensioner wheel is coupled to the arm for rotation about a wheel axis that is offset from the pivot axis. The spring biases the arm about the pivot axis in a predetermined direction relative to the tensioner element. The damping arrangement includes a damping shoe and a brake element. The damping shoe and the brake element are coupled to opposite ones of the arm and the tensioner element. The brake element defines an arcuate shoe surface against which the brake element is frictionally engaged. The arm is pivotable relative to the tensioner element about the pivot axis through a range of pivoting motion

Description

DAMPED BELT TENSIONER

FIELD

[0001] The present disclosure relates to a damped belt tensioner.

BACKGROUND

[0002] This section provides background information related to the present disclosure which is not necessarily prior art.

[0003] It is known in the art to provide damping in a tensioner used for tensioning a belt in a belt drive system. One damping configuration is inherent in the bushings that support the arm(s) of the tensioner for pivoting motion about a pivot axis. This damping is largely dependent upon spring forces within the tensioner that are directed through the bushings. Other common damping configurations utilize specialized bushings and and/or tangentially-directed spring forces to apply a drag force to the arm of the tensioner. While such damping configurations can be effective, they can be somewhat difficult to adjust to an individual situation, particularly when there is a need to change the magnitude of the damping through the range of travel of the arm of the tensioner.

SUMMARY

[0004] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0005] In one form, the present disclosure provides a tensioner that includes a first arm, a first tensioner wheel, a tensioner component, a spring and a damping arrangement. The first arm defines a pivot axis. The first tensioner wheel is coupled to the first arm for rotation about a first wheel axis that is offset from the pivot axis. The spring biases the first arm about the pivot axis in a predetermined direction relative to the tensioner component. The damping arrangement includes a damping shoe and a brake element. The damping shoe is coupled to one of the first arm and the tensioner component and defines at least one arcuate shoe surface. The brake element is coupled to the other one of the first arm and the tensioner component and is frictionally engaged to the at least one shoe surface. The first arm is pivotable relative to the tensioner component about the pivot axis through a range of pivoting motion.

[0006] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

[0007] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0008] Figure 1 is a perspective view of an exemplary tensioner constructed in accordance with the teachings of the present disclosure;

[0009] Figure 2 is an exploded perspective view of the tensioner of Figure 1 ;

[0010] Figure 3 is a section view of a portion of the tensioner of Figure 1 taken through a pivot axis and illustrating a first arm and a tensioner element in more detail; [0011] Figure 4 is a front exploded perspective view of a portion of the tensioner of Figure 1 illustrating the tensioner element, the first arm and a damping system in more detail;

[0012] Figure 5 is a rear exploded perspective view of the portion of the tensioner of Figure 1 that is illustrated in Figure 4;

[0013] Figure 6 is a view of a portion of the tensioner of Figure 1 , illustrating the first am positioned relative to the tensioner element in a first rotational position in the first arm’s range of travel relative to the tensioner element; and [0014] Figure 7 is a sectional view taken along the line 7-7 of Figure 6.

[0015] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0016] With reference to Figures 1 through 3 of the drawings, an exemplary tensioner constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 10. The tensioner 10 can include a base 12, a first arm assembly 14, a tensioner element 16, a closure member 18, a primary spring 20, a supplemental spring 22, first, second and third seals 24, 26 and 28, respectively, and a damping system 30. In the particular example provided, the tensioner 10 is configured to tension a belt (not shown) through contact with segments of the belt that are on opposite sides of a pulley (not shown). Accordingly, the tensioner element 16 is rotatable about a pivot axis 32 relative to both the base 12 and the first arm assembly 14 in the example provided and moreover, a (second) tensioner wheel 36 is rotatably coupled to the tensioner element 16 for pivoting motion about the pivot axis 32.

[0017] With specific reference to Figures 2 and 3, the base 12 can be disposed concentrically about the pivot axis 32 and can include a head 40, a shaft 42 and a coupling segment 44. In the example provided, a through-hole 46 is formed entirely through the base 12 and is configured to receive a fastener (not shown) therethrough that permits the base 12 to be fixedly coupled to a desired structure, such as an internal combustion engine (not shown). The head 40 is comparatively larger in diameter than the shaft 42 and defines a shoulder 48 at an axial end of the head 40 that is adjacent to the shaft 42. The head 40 can also define a seal groove 50 that is configured to receive the third seal 28. The opposite axial ends of the shaft 42 are fixedly coupled to the head 40 and the coupling segment 44. The shaft 42 has an exterior surface that is shaped as a right cylinder in the example provided. The coupling segment 44 can be relatively smaller in diameter than the shaft 42 and can cooperate with the shaft 42 to define a step 54 where the coupling segment 44 and the shaft 42 meet.

[0018] With reference to Figures 2 through 5, the first arm assembly 14 can have a first arm 60 and a first tensioner wheel 62. The first arm 60 can define a first pivot hub 68 and a first wheel hub 70. The first pivot hub 68 can define a first pivot aperture 72, a first spring aperture 74, a first seal surface 76 and a second seal surface 78. The first pivot hub 68 can optionally define a first spring guide 80 and a first spring abutment 84. The first pivot aperture 72 can be disposed about the pivot axis 32 and can receive the shaft 42 therein. The first spring aperture 74 can be formed as a recess in an axial end of the first pivot hub 68 and is sized to receive the primary spring 20 therein.

[0019] The first seal surface 76 can be formed as the bottom wall of a circumferentially extending groove 88 that is formed in a first, opposite axial end of the first pivot hub 68. The second seal surface 78 can be formed as the shoulder of a counterbore that is formed into a first axial end of the first pivot hub 68 concentric with the first spring aperture 74.

[0020] The configuration of the first spring guide 80 will vary depending on the configuration of the primary spring 20. In the example provided, the primary spring 20 is a helical compression spring that is formed of a wire whose opposite ends terminate at respective planes that are perpendicular to the longitudinal axis of the wire. Accordingly, the first spring guide 80 is a helical ramp that is configured to support at least a portion of one of the helical coils of the primary spring 20 that extends from a first axial end of the primary spring 20. The helical ramp can optionally be contoured so as to have a configuration that mates to or cradles the wire that forms the primary spring 20. Additionally or alternatively, the first spring guide 80 can have a lip member, which could be a projection formed on an outer circumferential wall of the first pivot hub 68, that is configured to extend about a portion of the primary spring 20 that can help to control the transmission of force or torque through the wire that forms the primary spring 20 and/or helps to maintain the primary spring 20 centered about the pivot axis 32.

[0021] The first spring abutment 84 is configured to transmit force or torque between the primary spring 20 and the first arm 60 Accordingly the configuration of the first spring abutment 84 is tailored to the particular type of spring that is employed. In the example provided, the first spring abutment 84 is a projection with a planar face that is formed perpendicular to the helix of the first spring guide 80 and is configured to abut a planar, axial end of the wire that forms the primary spring 20.

[0022] The first wheel hub 70 can define a first tensioner wheel axis 90 that can be parallel to but spaced apart from the pivot axis 32. The first tensioner wheel 62 can be mounted to the first wheel hub 70 for rotation about the first tensioner wheel axis 90. In the example provided, the first tensioner wheel 62 comprises a ball bearing 92 that is mounted to a cylindrically-shaped roller 94 and a threaded fastener 96 is threaded into the first wheel hub 70 to exert a clamping force on an inner bearing race of the ball bearing 92 to fixedly and non-rotatably couple the inner bearing race of the ball bearing 92 to the first arm 60. It will be appreciated, however, that the first tensioner wheel 62 could be formed somewhat differently, and/or could be mounted to the first wheel hub 70 differently, and/or could be configured as a pulley for engaging a desired tooth profile (e.g., with teeth, or with a V or poly-V configuration) or with a sprocket for engaging a chain. [0023] The first arm assembly 14 is configured to pivot relative to the tensioner element 16 about the pivot axis 32. In the particular example provided, the tensioner element 16 is a second arm that is also configured to pivot about the pivot axis 32 independently of the first arm assembly 14. It will be appreciated, however, that a tensioner constructed in accordance with the teachings of the present disclosure need only have one pivoting arm (i.e. , the first arm 60) and as such, the tensioner element 16 could be configured to be fixedly coupled to another structure, such as the base 12 (e.g., the base 12 and the tensioner element 16 could be unitarily and integrally formed with one another).

[0024] The tensioner element 16 can define a second pivot hub 98 and a second wheel hub 100. The second pivot hub 98 can define a second pivot aperture 102, a second spring aperture 104, a fourth seal surface 106, and a fifth seal surface 108. The second pivot hub 98 can also optionally define a second spring guide 110, and a second spring abutment 114. The second pivot aperture 102 can be formed through the tensioner element 16 along the pivot axis 32 and is configured to receive the shaft 42 therethrough. The second spring aperture 104 can be formed in a first axial end of the second arm (tensioner element 16) and can be concentric with the second pivot aperture 102. The counterbore that forms the second spring aperture 104 can be sized to receive the head 40 of the base 12 therein.

[0025] The fourth seal surface 106 can be formed on an axial end of a circumferentially extending shoulder that is disposed about the circumference of the second spring guide 110. The second seal 26 can be a lip seal that can be mounted about the second pivot hub 98 and can sealingly engage the second seal surface 78 and the fourth seal surface 106. The fifth seal surface 108 can be formed concentric with a counterbore that forms the second spring aperture 104. In the example provided, the fifth seal surface 108 and the counterbore that forms the second spring aperture 104 are sized the same, and optionally, the fifth seal surface 108 can be formed with a finer surface finish than the remainder of the diametrical surface of the counterbore that forms the second spring aperture 104. It will be appreciated, however, that the fifth seal surface 108 can be formed to a diameter that is larger than that of the counterbore that forms the second spring aperture 104. The third seal 28 can be received in the seal groove 50 in the head 40 and can sealingly engage the base 12 and the fifth seal surface 108. [0026] The second spring guide 110 is configured to support the primary spring 20 as the primary spring 20 biases the first arm 60 and the tensioner element 16 apart from another about the pivot axis 32. As such, the configuration of the second spring guide 110 will vary depending on the configuration of the primary spring 20. In the example provided, the second spring guide 110 is a helical ramp that is configured to support at least a portion of one of the helical coils that terminates at the second axial end of the primary spring 20. The helical ramp can optionally be contoured so as to have a configuration that mates to or cradles the wire that forms the primary spring 20. Additionally or alternatively, the second spring guide 110 could have a lip member that is configured to extend about a portion of the primary spring 20 that can help to control the transmission of force or torque through the wire that forms the primary spring 20 and/or helps to maintain the primary spring 20 centered about the pivot axis 32.

[0027] The second spring abutment 114 is configured to transmit force or torque between the primary spring 20 and the tensioner element 16. Accordingly, the configuration of the second spring abutment 114 is tailored to the particular type of spring that is employed. In the example provided, the second spring abutment 114 is a projection with a planar face that is formed perpendicular to the helix of the second spring guide 110 and is configured to abut a planar, axial end of the wire that forms the primary spring 20.

[0028] With reference to Figure 2, the second wheel hub 100 can define a second tensioner wheel axis 120 that can be parallel to but spaced apart from the pivot axis 32. The second tensioner wheel 36 can be mounted to the second wheel hub 100 for rotation about the second tensioner wheel axis 120. In the example provided, the second tensioner wheel 36 comprises a ball bearing 122 that is mounted to a cylindrically-shaped roller 124 and a threaded fastener 126 is threaded into the second wheel hub 100 to exert a clamping force on the inner bearing race of the ball bearing 122 to fixedly and non-rotatably couple the inner bearing race of the ball bearing 122 to the second arm 16. It will be appreciated, however, that the second tensioner wheel 36 could be formed somewhat differently, and/or could be mounted to the second wheel hub 100 differently, and/or could be configured as a pulley for engaging a desired tooth profile (e.g., with teeth, or with a V or poly-V configuration) or with a sprocket for engaging a chain.

[0029] With reference to Figures 2 and 3, the closure member 18 can be mounted on the coupling segment 44 and can be fixedly coupled to the base 12 in any desired manner. In the example provided, the coupling segment 44 is press-fit onto the coupling segment 44. The first seal 24 can be received in the groove 88 in the first pivot hub 68 and can sealingly engage the first seal surface 76 and a surface on the underside of the closure member 18.

[0030] If desired, a bushing or bearing can be disposed between the exterior surface of the shaft 42 and the inside diametrical surfaces of the first pivot aperture 72 and the second pivot aperture 102. In the example provided, two conventional flanged bushings 130 and 132 are employed to support the first arm 60 for pivoting motion relative to the shaft 42 about the pivot axis 32, as well as to transmit axial loads through the first arm 60. Each of the flanged bushings 130 and 132 has a tubular portion 134, which is received in the first pivot aperture 72, and a flange member 136 that extends radially outwardly from the tubular portion 134. The flange members 136 of the flanged bushings 130 and 132 are disposed against associated thrust surfaces 138 and 140 formed on a respective axial ends of the first pivot hub 68.

[0031] Similarly, a bushing or bearing can be disposed between the exterior surface of the shaft 42 and the inside diametrical surface of the second pivot aperture 102. In the example provided, two conventional flanged bushings 150 and 152, which can be identical to the flanged bushings 130 and 132, are employed to support the tensioner element 16 for pivoting motion relative to the shaft 42 about the pivot axis 32, as well as to transmit axial loads through the tensioner element 16. The tubular portion 134 of each of the flanged bushings 150 and 152 is received in the second pivot aperture 102, and the flange member 136 of the flanged bushing 152 is disposed against the end surface 154 of the second spring aperture 104 in the second pivot hub 98, while the flange member 136 of the flanged bushing 150 is disposed against an axial surface 156 on the second pivot hub 98. In the example provided, the second spring aperture 104, which is formed as a counterbore in an axial end of the second pivot hub 98, defines a thrust surface (i.e. , end surface 154) against which the flange member 136 of the flanged bushing 152 is abutted, while an axial end of the second pivot hub 98 that is opposite the head 40 defines another thrust surface (i.e., axial surface 156) against which the flange member 136 of the flanged bushing 150 is abutted.

[0032] As noted above, the primary spring 20 is configured to bias the first arm 60 about the pivot axis 32 in a predetermined rotational direction relative to the tensioner element 16. The primary spring 20 can be a helical coil compression spring that can have a plurality of helical coils disposed between a first end and a second end. In the example provided, each of the first and second ends is a planar surface formed perpendicular to a longitudinal axis of a wire that forms the helical coil compression spring. The primary spring 20 is configured to bias the first arm 60 apart from the tensioner element 16 about the pivot axis 32 in a predetermined rotational direction. The primary spring 20 can also be disposed in the load path between the head 40 and the first arm assembly 14 and can be compressed in an axial direction along the pivot axis 32 so as to generate a force that ultimately urges the first arm assembly 14 along the pivot axis 32 in a predetermined direction away from the tensioner element 16 and toward the closure member 18.

[0033] The supplemental spring 22, which is optional, is disposed in the load path between the head 40 and the closure member 18 and is configured to generate a supplemental force that augments any axial force that may be generated by the primary spring 20. The supplemental spring 22 can comprise a helical coil compression spring or a wave spring, for example, but in the example illustrated, the supplemental spring 22 comprises one or more Belleville spring washers that are received over the shaft 42 and disposed against the shoulder 48 on the head 40. The supplemental spring 22. While the supplemental spring 22 is shown in a location between the head 40 of the base 12 and the second pivot hub 98, those of ordinary skill in the art will appreciate that the supplemental spring 22 could be positioned in a different location in the load path, such as between the first and second pivot hubs 68 and 98, or between the first pivot hub 68 and the closure member 18.

[0034] Optionally, a washer-like thrust member 180 can be disposed on the base 12 in abutment with the supplemental spring 22 and the flange member 136 of the flanged bushing 152. The thrust member 180 can be configured to spread the load exerted by the supplemental spring 22 over a relatively larger surface area on an adjacent element to reduce localized stress and wear on the flange member 136 of the adjacent flanged bushing 152. The thrust member 180 can be formed of a desired material, such as steel, and can be received on the shaft 42 adjacent to the supplemental spring 22. Also optionally, a similar washer-like thrust member 182 can be disposed about the shaft 42 axially between the flange members 136 of the flanged bushings 132 and 150. [0035] With reference to Figures 4, 5 and 7, the damping system 30 is configured to dampen movement of the first arm assembly 14 about the pivot axis 32 relative to the tensioner element 16 and/or the base 12, and/or to dampen movement of the tensioner element 16 about the pivot axis 32 relative to the first arm assembly 14 or the base 12. The damping system 30 can comprise one or more brake elements 200, one or more damping shoes 202, and optionally one or more damping springs 204.

[0036] Each of the brake elements 200 can be a post-like structure that can be fixedly coupled to a first one of the first arm assembly 14 (Fig. 2), the tensioner element 16 and the base 12 (Fig. 2), while each of the damping shoes 202 can be coupled to a second (i.e. , different) one of the first arm assembly 14 (Fig. 2), the tensioner element 16 and the base 12 (Fig. 2) and can engage an associated brake element 200 to dampen relative rotational movement between the first and second ones of the first arm assembly 14 (Fig. 2), the tensioner element 16 and the base 12 (Fig. 2) about the pivot axis 32. In the example provided, the brake element 200 is an arcuate post that is integrally and unitarily formed with the first arm 60, extends along an axis that is parallel to the pivot axis 32, and has a lateral cross-section (shown in Fig. 7) that is symmetrically shaped (i.e., mirrored) about a radius (r) that is centered about the pivot axis 32. The brake element 200 defines radially inner and outer brake surfaces 210 and 212, respectively, that are concentric with one another in the example provided. It will be appreciated, however, that the brake element 200 could be a discrete component that could be coupled to the first arm 60, such as a cylindrical post (not shown) that is threaded into an aperture (not shown) formed in the first arm 60, and/or that the brake element 200 could extend along an axis that is transverse to the pivot axis 32.

[0037] In the example provided, a single damping shoe 202 is employed and is fixedly coupled to the tensioner element 16. The damping shoe 202 can include a shoe mount 216 and at least one shoe surface that is configured to engage an associated brake surface either throughout the entire range of relative rotation between the first and second ones of the first arm assembly 14 (Fig. 2), the tensioner element 16 and the base 12 (Fig. 2) or at one or more points in the range of relative rotation between the first and second ones of the first arm assembly 14 (Fig. 2), the tensioner element 16 and the base 12 (Fig. 2). In the example shown, the damping shoe 202 defines radially inner and outer shoe surfaces 220 and 222, respectively, that engage or are engagable to the radially inner and outer brake surfaces 210 and 212, respectively, throughout the entire range of relative rotation between the first arm 60 and the tensioner element 16. The shoe mount 216, which is optional, is configured to couple the damping shoe 202 to an associated one of the first arm assembly 14, the tensioner element 16 and the base 12. In the example provided, the damping shoe 202 is configured to be received into a blind recess 226 (best shown in Figure 4) that is formed in the tensioner element 16, and the shoe mount 216 includes a recess 228 that is configured to accept a first projection 230 that is integrally formed with the tensioner element 16 and which extends into the blind recess 226. Receipt of the damping shoe 202 into the blind recess 226 and engagement of the first projection 230 into the recess 228 fixedly couples the damping shoe 202 to the tensioner element 16. In some examples, a slot 236 can be formed through the component to which the damping shoe 202 is mounted (i.e. , the tensioner element 16 in the example provided) in-line with a slot 238 in the damping shoe 202 that defines that defines the radially inner and outer shoe surfaces 220 and 222. The slots 236 and 238 are configured to receive the brake element 200 during assembly of the tensioner 10 (Fig. 2). More specifically the first arm 60 can be aligned to the tensioner element 16 and the first arm 60 can be rotated about the pivot axis 32 relative to the tensioner element 16 to move the brake element 200 through the slot 236 in the tensioner element 16 and through the open end of the slot 238 in the damping shoe 202 so that the radially inner and outer brake surfaces 210 and 212 contact the radially inner and outer shoe surfaces 220 and 222, respectively. In the example provided, the slot 238 extends from a first axial end (i.e., front side) of the damping shoe 202 and does not intersect a second, opposite axial end of the damping shoe 202 (i.e., the slot 238 extends partly through the depth of the damping shoe 202). A second, narrower slot extends between the rear of the slot 238 through the second axial end (i.e., rear side) of the damping shoe 202. The slot 238 and the second slot cooperate to decouple the radially inner and outer shoe surfaces 220 and 222 from one another.

[0038] In the example provided, the damping system 30 includes first and second damping springs 204a and 204b, respectively. The first damping spring 204a can be fixedly coupled to the tensioner element 16 and can urge a segment of the radially inner shoe surface 220 outwardly against the radially inner brake surface 210. For example, one of the tensioner element 16 and the first damping spring 204a can define a projection 246 that is received into a recess 248 that is formed in the other one of the tensioner element 16 and the first damping spring 204a. The second damping spring 204b can be received in a spring pocket 250 formed in the damping shoe 202 and can abut the tensioner element 16 on a radially outer side of the blind recess 226. The second damping spring 204b can engage the damping shoe 202 to generally drive the radially outer brake surface 212 toward the radially outer brake surface 212. In the example shown, the first damping spring 204a is configured to urge the radially inner shoe surface 220 against the radially inner brake surface 210 throughout substantially all of the range of relative movement between the first arm 60 and the tensioner element 16, while the second damping spring 204b is configured to urge the radially outer shoe surface 222 against the radially outer brake surface 212 throughout a middle portion of the range of relative movement between the first arm 60 and the tensioner element 16. Configuration in this manner essentially provides reduced damping at the ends of the travel of the first arm 60 relative to the tensioner element 16.

[0039] It will be appreciated that various techniques can be employed to influence the magnitude of damping between two components of the tensioner 10, either throughout the range of travel of one tensioner component relative to the other tensioner component, or through a portion of the range of travel of one tensioner component relative to the other tensioner component. For example, the tribological properties of one or more of the brake surfaces and/or the shoe surfaces could be configured so as to provide a higher degree of damping when relative movement between the two tensioner components is in one rotational direction about the pivot axis than the other rotational direction. Additionally or alternatively, the tribological properties of one or more of the brake surfaces and/or the shoe surfaces could be configured in a manner that varies through the range of travel between the two tensioner components. For example, the tribological properties of one or more of the brake surfaces and/or the shoe surfaces could be configured to provide no damping at one or more portions of the range of travel between the two tensioner components, such as locations within the range that permit the installation of a belt of a belt drive system but which would not be utilized during operation of the belt drive system.

[0040] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

CLAIMS What is claimed is:

1. A tensioner (10) comprising: a first arm (60) disposed about a pivot axis (32); a first tensioner wheel (62) that is coupled to the first arm (60) for rotation about a first wheel axis (90) that is offset from the pivot axis (32); a tensioner component (12, 16); a spring (20) biasing the first arm (60) about the pivot axis (32) in a predetermined direction relative to the tensioner component (12, 16); and a damping system (30) comprising: a damping shoe (202) coupled to one of the first arm (60) and the tensioner component (12, 16), the damping shoe (202) defining at least one arcuate shoe surface (220, 222); and a brake element (200) coupled to the other one of the first arm (60) and the tensioner component (12, 16), the brake element (200) being frictionally engaged to the at least one shoe surface (220, 222); wherein the first arm (60) is pivotable relative to the tensioner component (12, 16) about the pivot axis (32) through a range of pivoting motion.

2. The tensioner (10) of Claim 1, wherein the spring (20) is a helical compression spring having a first end, which is engaged to the first arm (60), and a second end that is engaged to the tensioner component (12, 16).

3. The tensioner (10) of Claim 2, wherein each of the first arm (60) and the tensioner component (12, 16) has an abutment that engages an axial end of a wire from which the spring (20) is formed.

4. The tensioner (10) of Claim 1, wherein the one of the first arm (60) and the tensioner component (12, 16) defines a recess (226) into which the damping shoe (202) is received.

5. The tensioner (10) of Claim 4, wherein the one of the damping shoe (202) and the recess (226) defines a projection (230) and the other one of the damping shoe (202) and the recess (226) defines an aperture (228) into which the projection (230) is received.

6. The tensioner (10) of Claim 4, wherein the at least one arcuate shoe surface (220, 222) comprises a radially inner shoe surface (220) and a radially outer shoe surface (222) that cooperate to define a first arcuate slot (238) into which the brake element (200) is disposed.

7. The tensioner (10) of Claim 6, wherein the damping system (30) comprises a pair of damping springs (204a, 204b), each of the damping springs (204a, 204b) biasing an associated one of the radially inner and outer shoe surfaces (220, 222) in a corresponding radial direction toward the brake element (200).

8. The tensioner (10) of Claim 7, wherein at least one of the damping springs (204a, 204b) is a leaf spring.

9. The tensioner (10) of Claim 6, wherein the damping shoe (202) defines a spring pocket (250) into which an associated one of the damping springs (204a, 204b) is received.

10. The tensioner (10) of Claim 6, wherein the first arcuate slot (238) is formed in a first axial end of the damping shoe (202) but does not extend fully through the damping shoe (202) to a second axial end of the damping shoe (202).

11. The tensioner (10) of Claim 10, wherein the first arcuate slot (238) extends through a radial end of the damping shoe (202).

12. The tensioner (10) of Claim 11, wherein the portion of the first arcuate slot (238) that extends through the radial end of the damping shoe (202) is aligned to a channel (236) that is formed in the one of the first arm (60) and the tensioner component (12, 16), and wherein the channel (236) permits the brake element (200) to move through the wherein the one of the first arm (60) and the tensioner component (12, 16) and into the first arcuate slot (238) when the tensioner (10) is assembled.

13. The tensioner (10) of Claim 4, wherein the damping system (30) further comprises a damping spring (204a, 204b) that biases the damping shoe (202) in a radial direction toward the brake element (200), wherein the one of the damping spring (204a, 204b) and the one of the first arm (60) and the tensioner component (12, 16) defines a projection (246) that is received into a recess (248) that is formed in the other one of the damping spring (204a, 204b) and the one of the first arm (60) and the tensioner component (12, 16).

14. The tensioner (10) of Claim 1 , wherein the tensioner component (12, 16) is a second arm and wherein the tensioner (10) further comprises a base (12) and a second tensioner wheel (36), wherein the second arm is pivotably coupled to the base (12) and wherein the second wheel (36) is coupled to the second arm for rotation about a second wheel axis (120) that is offset from the pivot axis (32).

15. The tensioner (10) of Claim 1 , wherein the tensioner component (12, 16) is non-rotatably coupled to a base (12) that is adapted to be fixedly mounted to another structure.