# US 10,865,858 B2 · Belt tensioner > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,858 B2 - Document ID: US10865858B2 - Status: Granted - Kind: B2 - Application number: 15/578,926 - Filed: 2016-05-30 - Published: 2018-06-21 - Granted: 2020-12-15 - Earliest claimed: 2015-06-01 - Assignees: Schaeffler Technologies AG & Co.KG - Applicants: Schaeffler Technologies AG & Co. KG - Inventors: Roland Arneth; Alexander Weidner; Zoran Maricic - Web page: https://patentgrep.com/patent/US10865858B2 ## CPC - F16H 7/1281: {where the axis of the pulley moves along a substantially circular path} - F16H 7/08: Means for varying tension of belts, ropes or chains (pulleys of adjustable construction F16H55/52) - F02B 67/06: driven by means of chains, belts, or like endless members - F02N 11/04: the motors being associated with current generators - F16H 2007/0806: {Compression coil springs} - F16H 2007/0865: {Pulleys} - F16H 2007/0874: {Two or more finally actuated members} - F16H 2007/0893: {Circular path} - F16H: GEARING - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F02N: STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR ## Abstract A belt tensioner, comprising a first and second tensioning arm supported on a generator housing, a first and second tensioning roller attached to the first and second tensioning arms and configured to apply a pre-tensioning force to an auxiliary unit belt drive, and a bow spring clamped between the first and second tensioning arms in axial overlap with the tensioning rollers and configured to produce the pre-tensioning force. ## Claims ### Claim 1 A belt tensioner for an auxiliary-unit belt drive, which auxiliary-unit belt drive includes a generator having a generator housing, a generator shaft, and a generator pulley, around which a belt is wrapped, comprising: a first and second tensioning arms supported on the generator housing in pivotable in relation to each other and in relation to the generator and which enclose the generator shaft, a first and second tensioning rollers attached to the first and second tensioning arms respectively and configured to apply pre-tensioning force to the belt in a circulation direction thereof before and after the generator pulley, and a bow spring configured to produce the pre-tensioning force, wherein the bow spring is clamped between the tensioning arms in axial overlap with the tensioning rollers, wherein the tensioning arms restrict an arcuate spring space that accommodates the bow spring, and a wrap-around region of the generator pulley and is limited by two walls of a first tensioning arm, wherein the bow spring is clamped between a first wall of the two walls and a driver of the second tensioning arm, wherein the driver includes a protrusion that protrudes axially with respect to a circular-ring shaped end face of the second tensioning arm and protrudes into the arcuate spring space before a second wall of the two walls. ### Claim 2 (depends on 1) The belt tensioner of claim 1, wherein the bow spring is attached onto the two walls, wherein the second wall of the two walls includes a recess that accommodates the driver when the second tensioning arm is mounted to the first tensioning arm. ### Claim 3 (depends on 1) The belt tensioner of claim 1, wherein a circumference of the bow spring and one or more sliding blocks are configured to support a reaction force of the bow spring in a radial outer direction toward an inner sheath of the arcuate spring space and in axial direction toward a floor of the arcuate spring space or a circular-ring shaped end face of the second tensioning arm facing the arcuate spring space. ### Claim 4 (depends on 1) The belt tensioner of claim 1, wherein the second tensioning arm is supported in such a way that it has no contact with the generator housing. ### Claim 5 (depends on 4) The belt tensioner of claim 4, wherein the second tensioning arm is provided with a glide coating for a mutual radial and axial support of the tensioning arms. ### Claim 6 (depends on 1) The belt tensioner of claim 1, wherein the arcuate spring space is limited by an arcuate curvature of the first tensioning arm, wherein on an outer side of the arcuate curvature, a bearing ring is attached on the generator housing for pivot bearing of the belt tensioner. ### Claim 7 (depends on 6) The belt tensioner of claim 6, wherein the belt tensioner is pivotally mounted to the generator, wherein the bearing ring is covered with a glide coating and supported in axial direction between an end face of the generator housing and an end face of a bearing cover attached on the generator housing. ### Claim 8 (depends on 7) The belt tensioner of claim 7, wherein the end face of the generator housing is part of a depression, wherein the generator housing further includes an inner sheath of which the glide coating of the bearing ring is supported in a radial direction. ### Claim 9 (depends on 8) The belt tensioner of claim 8, wherein the bearing cover includes a planar sheet metal part. ### Claim 10 A belt tensioner, comprising: a first and second tensioning arm supported on a generator housing; a first and second tensioning roller attached to the first and second tensioning arms respectively and configured to apply a pre-tensioning force to an auxiliary-unit belt drive; and a bow spring clamped between the first and second tensioning arms in axial overlap with the first and second tensioning rollers and configured to produce the pre-tensioning force; and a driver of the second tensioning arm, wherein the driver includes a protrusion that protrudes axially with respect to a circular-ring shaped end face of the second tensioning arm and protrudes into an arcuate spring space before a second wall of the first tensioning arm, wherein the first and second tensioning arms restrict the arcuate spring space that accommodates the bow spring, and a wrap-around region of a generator pulley that is limited by a first wall of the first tensioning arm, wherein the bow spring is clamped between the first wall and the driver. ### Claim 11 (depends on 10) The belt tensioner of claim 10, wherein the bow spring is clamped between the first wall of the first tensioning arm that includes a recess, and the driver of the second tensioning arm. ### Claim 12 (depends on 11) The belt tensioner of claim 11, wherein the driver protrudes axially with respect to the circular-ring shaped end face of the second tensioning arm and protrudes into an arcuate spring space before the second wall. ### Claim 13 (depends on 10) The belt tensioner of claim 10, the first and second tensioning arms restrict the arcuate spring space that accommodates the bow spring, and a circumferential extent that runs in the wrap-around region of the generator pulley is limited by the first wall and the second wall of the first tensioning arms. ### Claim 14 (depends on 10) The belt tensioner of claim 10, wherein at an external arc of the bow spring includes one or more sliding blocks configured to support a reaction force in a radial direction. ### Claim 15 (depends on 10) The belt tensioner of claim 10, wherein the bow spring includes a first spring end attached at a low pre-tension at the first wall. ### Claim 16 A belt tensioner, comprising: a bow spring configured to produce a pre-tensioning force, wherein the bow spring is clamped between a first and second tensioning arms in axial overlap with first and second tensioning rollers, wherein the second tensioning arm includes a driver, wherein the bow spring is clamped between a first wall of the first tensioning arm and the driver of the second tensioning arm, wherein the bow spring is in axial overlap of a wrap-around region of a generator pulley of the belt tensioner and the driver of the second tensioning arm, wherein the driver includes a protrusion that protrudes axially with respect to a circular-ring shaped end face of the second tensioning arm and protrudes into an arcuate spring space before a second wall of the first tensioning arm. ### Claim 17 (depends on 16) The belt tensioner of claim 16, wherein the bow spring is accommodated in parallel fashion to a belt plane in the respective arcuate spring space of the first tensioning arm. ### Claim 18 (depends on 16) The belt tensioner of claim 16, wherein the bow spring includes one or more sliding blocks configured to support a reaction force of the bow spring. ### Claim 19 (depends on 18) The belt tensioner of claim 18, wherein the one or more sliding blocks are configured to support the reaction force of the bow spring in a radial outer direction. ### Claim 20 (depends on 18) The belt tensioner of claim 18, wherein the one or more sliding blocks are configured to support the reaction force of the bow spring in bilateral axial direction at the first tensioning arm.