# US 10,502,270 B2 · Vehicular power transmitting system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,270 B2 - Document ID: US10502270B2 - Status: Granted - Kind: B2 - Application number: 15/904,920 - Filed: 2018-02-26 - Published: 2018-08-30 - Granted: 2019-12-10 - Earliest claimed: 2017-02-26 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Toyota Jidosha Kabushiki Kaisha - Inventors: Michio Yoshida; Hirofumi Nakada; Kazunori Saito - Web page: https://patentgrep.com/patent/US10502270B2 ## CPC - F16D 23/06: and a blocking mechanism preventing the engagement of the main clutch prior to synchronisation - F16D 11/14: with clutching members movable only axially (F16D11/02, F16D11/08 take precedence) - F16D 25/06: in which the fluid actuates a piston incorporated in, {i.e. rotating with} the clutch (F16D25/02 takes precedence) - F16D 25/086: {the clutch being actuated by a push rod extending coaxially through the input or output shaft} - F16D 25/123: {in view of cooling and lubrication} - F16H 57/0424: {Lubricant guiding means in the wall of or integrated with the casing, e.g. grooves, channels, holes} - F16H 57/043: {within rotary parts, e.g. axial channels or radial openings in shafts} - F16H 57/0471: {Bearing} - F16H 57/0478: {Synchromesh devices} - F16H 63/3023: {the final output mechanisms comprising elements moved by fluid pressure (band brake actuating mechanisms F16H63/3003)} - B60Y 2400/72: Continous variable transmissions [CVT] - F16D 2023/0631: {Sliding sleeves; Details thereof} - F16D 2023/0693: {Clutches with hydraulic actuation} - F16D 2300/06: Lubrication details not provided for in group F16D13/74 - F16D 2300/24: Concentric actuation rods, e.g. actuation rods extending concentrically through a shaft - F16D 2500/10462: Dog-type clutch - F16H 2063/3093: {Final output elements, i.e. the final elements to establish gear ratio, e.g. coupling sleeves or other means establishing coupling to shaft} - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - F16H: GEARING - B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY ## Abstract A power transmitting system including: a first piston disposed within a center bore formed through the rotary shaft such that the first piston is axially reciprocable; a sleeve connected to the first piston and having internal teeth meshing with the external teeth of the rotary shaft so that the sleeve is rotated with the rotary shaft, and such that the sleeve is axially reciprocable together with the first piston according to axial movements of the first piston; a synchronizer ring supported in sliding contact with an outer circumferential tapered surface of the clutch gear such that the synchronizer ring is rotatable relative to the clutch gear; and an actuator including a second piston to axially advance the first piston for thereby bringing the sleeve's internal teeth into meshing engagement with the clutch gear through the synchronizer ring. The first piston and second piston are disposed coaxially with the rotary shaft. ## Claims ### Claim 1 A vehicular power transmitting system including a dog clutch having a synchro-mesh mechanism, which dog clutch is provided to selectively connect and disconnect a rotary shaft having external teeth, and a clutch gear rotatable relative to the rotary shaft, to and from each other, the clutch gear having a tapered outer circumferential surface, the vehicular power transmitting system comprising: a first piston disposed within a center bore formed through the rotary shaft such that the first piston is axially reciprocable; a sleeve connected to the first piston and having internal teeth meshing with the external teeth of the rotary shaft so that the sleeve is rotated with the rotary shaft, and such that the sleeve is axially reciprocable together with the first piston according to axial movements of the first piston; a synchronizer ring supported in sliding contact with the tapered outer circumferential surface of the clutch gear such that the synchronizer ring is rotatable relative to the clutch gear; and an actuator including a second piston to axially advance the first piston for thereby bringing the internal teeth of the sleeve into meshing engagement with the clutch gear through the synchronizer ring, and wherein the first piston and the second piston are disposed coaxially with the rotary shaft. ### Claim 2 (depends on 1) The vehicular power transmitting system according to claim 1, further comprising an elastic member disposed between an outer circumferential surface of the first piston and an inner circumferential surface of the rotary shaft to bias the first piston in a direction for disengagement of the internal teeth of the sleeve from the clutch gear. ### Claim 3 (depends on 2) The vehicular power transmitting system according to claim 2, wherein the elastic member is a coil spring disposed coaxially with the first piston. ### Claim 4 (depends on 2) The vehicular power transmitting system according to claim 2, wherein the first piston is axially retracted in a direction away from the clutch gear with a biasing force of the elastic member while the first piston is not axially advanced by the second piston. ### Claim 5 (depends on 1) The vehicular power transmitting system according to claim 1, wherein the rotary shaft is supported by a pair of support walls via a pair of bearings, and the second piston is at least partly accommodated within one of the pair of support walls. ### Claim 6 (depends on 5) The vehicular power transmitting system according to claim 5, wherein the actuator is a hydraulic actuator having a piston fitting hole which is formed in said one of the pair of support walls coaxially with the second piston and in which the second piston is slidably and oil-tightly fitted, the second piston and the piston fitting hole cooperating to define an oil chamber. ### Claim 7 (depends on 6) The vehicular power transmitting system according to claim 6, wherein the oil chamber is a cylindrical space formed coaxially with the rotary shaft. ### Claim 8 (depends on 6) The power transmitting system according to claim 6, wherein the hydraulic actuator includes a mechanically operated hydraulic pump or an electrically operated hydraulic pump to pressurize a working fluid in the oil chamber, for thereby axially moving the second piston in a direction toward the first piston. ### Claim 9 (depends on 5) The vehicular power transmitting system according to claim 5, wherein the rotary shaft has a center bore in which the first piston and an axial end portion of the second piston are accommodated, and a lubricant is supplied into the center bore through one of opposite axial open ends of the center bore which is on the side of the other of the pair of support walls, the clutch gear being mounted on the rotary shaft via a needle bearing such that the clutch gear is rotatable relative to the rotary shaft, the rotary shaft having at least one radial oil passage formed so as to extend therethrough in its radial direction, so that the lubricant is delivered from the center bore to the needle bearing through the at least one radial oil passage. ### Claim 10 (depends on 9) The vehicular power transmitting system according to claim 9, wherein the rotary shaft has a guide hole extending in its axial direction, for fluid-communication with the center bore, and the sleeve is connected to the first piston through a connecting member which extends through the guide hole and which is fixed to the first piston. ### Claim 11 (depends on 1) The vehicular power transmitting system according to claim 1, wherein a damper member is interposed between the first and second pistons, and the first piston is held in abutting contact with the second piston via the damper member such that the first piston is rotatable relative to the second piston. ### Claim 12 (depends on 11) The vehicular power transmitting system according to claim 11, wherein the damper member is bonded to an axial end face of the second piston on the side of the first piston. ### Claim 13 (depends on 1) The vehicular power transmitting system according to claim 1, wherein the first piston is located in an axially middle portion of the rotary shaft. ### Claim 14 (depends on 1) The vehicular power transmitting system according to claim 1, wherein the first piston is located in an axial end portion of the rotary shaft which is on the side of the second piston.