# US 9,428,245 B2 · Bicycle drive unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,428,245 B2 - Document ID: US9428245B2 - Status: Granted - Kind: B2 - Application number: 13/928,606 - Filed: 2013-06-27 - Published: 2014-05-01 - Granted: 2016-08-30 - Earliest claimed: 2012-10-25 - Assignees: Shimano Inc. - Applicants: Shimano Inc. - Inventors: Yusuke Nishikawa; Tetsuya Hino - Web page: https://patentgrep.com/patent/US9428245B2 ## CPC - B62M 6/55: power-driven at crank shafts parts - Y10T 74/19647: Parallel axes or shafts - B62M: RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR {SINGLE-TRACK} CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES (arrangements or mounting of transmissions in vehicles in general B60K; transmission elements per se F16) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A drive unit has three axles, three rotation transmitting members and an acting force detecting unit. The first axle is configured to be rotated by a crank arm. The first rotation transmitting member is arranged on the first axle to transmit rotation of the first axle by the crank arm. The second axle is spaced from the first axle. The second rotation transmitting member is arranged on the second axle, and is operatively engaged with the first rotation transmitting member to transmit rotation of the first rotation transmitting member. The third axle is spaced from the first axle and the second axle. The third rotation transmitting member is arranged on the third axle, and operatively engaged with the second rotation transmitting member to transmit rotation of the second rotation transmitting member. The acting force detecting unit arranged to detect a force acting on the second axle. ## Claims ### Claim 1 A bicycle drive unit comprising: a first axle configured to be rotated by a crank arm; a first rotation transmitting member arranged on the first axle to transmit rotation of the first axle by the crank arm; a second axle spaced from the first axle; a second rotation transmitting member arranged on the second axle, and operatively engaged with the first rotation transmitting member to transmit rotation of the first rotation transmitting member; a third axle spaced from the first axle and the second axle; a third rotation transmitting member arranged on the third axle, and operatively engaged with the second rotation transmitting member to transmit rotation of the second rotation transmitting member; an acting force detecting unit arranged to detect a force acting on the second axle; and a housing that accommodates the first, second, and third rotation transmitting members, the first rotation transmitting member, the second rotation transmitting member, and the third rotation transmitting member being arranged in a rotation transmitting path between the first axle and a front sprocket. ### Claim 2 (depends on 1) The bicycle drive unit according to claim 1, wherein the second rotation transmitting member is rotatably supported on the second axle to rotate with respect to the second axle. ### Claim 3 (depends on 1) The bicycle drive unit according to claim 1, wherein the third rotation transmitting member is rotatably supported on the third axle to rotate with respect to the third axle. ### Claim 4 (depends on 1) The bicycle drive unit according to claim 1, wherein the first axle, the second axle and the third axle are arranged parallel with respect to each other. ### Claim 5 (depends on 1) The bicycle drive unit to claim 1, wherein the first rotation transmitting member, the second rotation transmitting member and the third rotation transmitting member are made of parts selected from the group consisting of gears, sprockets and pulleys. ### Claim 6 (depends on 1) The bicycle drive unit according to claim 1, wherein the first rotation transmitting member and the second rotation transmitting member are in direct contact with each other. ### Claim 7 (depends on 1) The bicycle drive unit according to claim 1, further comprising a first connecting member transmitting the rotation of the first rotation transmitting member to the second rotation transmitting member. ### Claim 8 (depends on 1) The bicycle drive unit according to claim 1, further comprising a second connecting member transmitting the rotation of the second rotation transmitting member to the third rotation transmitting member. ### Claim 9 (depends on 1) The bicycle drive unit according to claim 1, further comprising a chain engaged a first sprocket of the second rotation transmitting member and a second sprocket of the third rotation transmitting member to transmit the rotation of the second rotation transmitting member to the third rotation transmitting member, the first rotation transmitting member including a first gear and the second rotation transmitting member including a second gear engaged with the first gear, the first sprocket being connected to the second gear such that the first sprocket rotates with the second gear as a unit. ### Claim 10 (depends on 1) The bicycle drive unit according to claim 1, wherein the first axle is a crank axle, and the first rotation transmitting member is fixed on the first axle. ### Claim 11 A bicycle drive unit comprising: a first axle configured to be rotated by a crank arm; a first rotation transmitting member arranged on the first axle to transmit rotation of the first axle by the crank arm; a second axle spaced from the first axle; a second rotation transmitting member arranged on the second axle, and operatively engaged with the first rotation transmitting member to transmit rotation of the first rotation transmitting member; a third axle spaced from the first axle and the second axle; a third rotation transmitting member arranged on the third axle, and operatively engaged with the second rotation transmitting member to transmit rotation of the second rotation transmitting member; and an acting force detecting unit arranged to detect a force acting on the second axle, the first rotation transmitting member being engaged with the second rotation transmitting member to apply a first acting force component of the force acting on the second axle that acts in a radial direction of the second axle due to transmission of the rotation from the first rotation transmitting member to the second rotation transmitting member, and the second rotation transmitting member being engaged with the third rotation transmitting member to apply a second acting force component of the force acting on the second axle that acts in the radial direction of the second axle due to transmission of the rotation from the second rotation transmitting member to the third rotation transmitting member. ### Claim 12 (depends on 11) The bicycle drive unit according to claim 11, wherein the acting force detecting unit has a supporting part that supports the second axle and a sensor that detects the force acting on the second axle via the supporting part. ### Claim 13 (depends on 12) The bicycle drive unit according to claim 12, wherein the sensor is arranged to directly detect a strain of the supporting part, which is generated by the force acting on the second axle. ### Claim 14 (depends on 13) The bicycle drive unit according to claim 13, wherein the supporting part has an axle supporting portion that supports an end portion of the second axle, and a strain-generating portion in contact with the axle supporting portion. ### Claim 15 (depends on 13) The bicycle drive unit according to claim 13, wherein the sensor includes a strain gauge element. ### Claim 16 (depends on 12) The bicycle drive unit according to claim 12, further comprising a housing accommodating the first rotation transmitting member, the second rotation transmitting member and the third rotation transmitting member, and the supporting part is supported in the housing. ### Claim 17 A bicycle drive unit comprising: a first axle configured to be rotated by a crank arm; a first rotation transmitting member arranged on the first axle to transmit rotation of the first axle by the crank arm; a second axle spaced from the first axle; a second rotation transmitting member arranged on the second axle, and operatively engaged with the first rotation transmitting member to transmit rotation of the first rotation transmitting member; a third axle spaced from the first axle and the second axle; a third rotation transmitting member arranged on the third axle, and operatively engaged with the second rotation transmitting member to transmit rotation of the second rotation transmitting member; and an acting force detecting unit arranged to detect a force acting on the second axle, the second rotation transmitting member and the third rotation transmitting member are in direct contact with each other. ### Claim 18 A bicycle drive unit comprising: a first axle configured to be rotated by a crank arm; a first rotation transmitting member arranged on the first axle to transmit rotation of the first axle by the crank arm; a second axle spaced from the first axle; a second rotation transmitting member arranged on the second axle, and operatively engaged with the first rotation transmitting member to transmit rotation of the first rotation transmitting member; a third axle spaced from the first axle and the second axle; a third rotation transmitting member arranged on the third axle, and operatively engaged with the second rotation transmitting member to transmit rotation of the second rotation transmitting member; an acting force detecting unit arranged to detect a force acting on the second axle; a first connecting member transmitting the rotation of the first rotation transmitting member to the second rotation transmitting member; and a second connecting member transmitting the rotation of the second rotation transmitting member to the third rotation transmitting member, the first connecting member and the second connecting member being selected from the group consisting of chains or belts. ### Claim 19 A bicycle drive unit comprising: a first axle configured to be rotated by a crank arm; a first rotation transmitting member arranged on the first axle to transmit rotation of the first axle by the crank arm; a second axle spaced from the first axle; a second rotation transmitting member arranged on the second axle, and operatively engaged with the first rotation transmitting member to transmit rotation of the first rotation transmitting member; a third axle spaced from the first axle and the second axle; a third rotation transmitting member arranged on the third axle, and operatively engaged with the second rotation transmitting member to transmit rotation of the second rotation transmitting member; an acting force detecting unit arranged to detect a force acting on the second axle; a power transmission unit transmitting a rotating force of the third rotation transmitting member; and a motor operatively coupled to the power transmission unit to apply a driving force on the power transmission unit. ### Claim 20 (depends on 19) The bicycle drive unit according to claim 19, wherein the first axle and a rotating axle of the motor are arranged coaxially. ### Claim 21 (depends on 19) The bicycle drive unit according to claim 19, further comprising a transmission mechanism arranged in the power transmission path between the third rotation transmitting member and the power transmission unit. ### Claim 22 (depends on 19) The bicycle drive unit according to claim 19, further comprising a one-way clutch arranged to transmit a drive force of the motor to the power transmission unit.