# US 2014/0155212 A1 · Shift Power Transmission Apparatus and Travel Power Transmission Device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0155212 A1 - Document ID: US20140155212A1 - Status: Published application - Kind: A1 - Application number: 14/007,775 - Filed: 2012-03-27 - Published: 2014-06-05 - Earliest claimed: 2011-03-31 - Assignees: Kubota Corporation - Inventors: Yuji Kato; Seiji Ohkubo; Go Takagi; Seiji Norita; Takashi Okuyama; Kozo Nishikawa; Fumitake Okunishi; Yukifumi Yamanaka; Takahiro Uchi - Web page: https://patentgrep.com/patent/US20140155212A1 ## CPC - F16H 47/04: the mechanical gearing being of the type with members having orbital motion - F16H 47/08: the mechanical gearing being of the type with members having orbital motion - F16H 2037/0886: {with switching means, e.g. to change ranges} - F16H 2200/2005: with one sets of orbital gears - F16H: GEARING ## Abstract Disclosed is a shift power transmission apparatus for readily suppressing or avoiding size increase thereof. The apparatus includes an input shaft (22) receiving engine drive force, a hydraulic continuously variable transmission (30) driven by the input shaft (22), a planetary power transmission section (40) combining drive force from the input shaft (22) and output from the hydraulic continuously variable transmission (30) for outputting the combined drive force, and an output rotary member (24) outputting power to a travel apparatus. The planetary power transmission section (40) and the output rotary member (24) are arranged on a side of the hydraulic continuously variable transmission (30) associated with an engine-coupled side of the input shaft (22). The drive force is inputted to the planetary power transmission section (40) from a portion between the engine-coupled side and the hydraulic continuously variable transmission-coupled side of the input shaft (22). ## Claims ### Claim 1 A shift power transmission apparatus comprising: an input shaft receiving engine drive force; a hydraulic continuously variable transmission driven by the input shaft; a planetary power transmission section combining the drive force from the input shaft and an output from the hydraulic continuously variable transmission for outputting the combined drive force therefrom; and an output rotary member outputting power to a travel apparatus, wherein the planetary power transmission section and the output rotary member are arranged on a side of the hydraulic continuously variable transmission associated with an engine-coupled side of the input shaft; and wherein the drive force is inputted to the planetary power transmission section from a portion between the engine-coupled side and a hydraulic continuously variable transmission-coupled side of the input shaft. ### Claim 2 (depends on 1) The shift power transmission apparatus according to claim 1, wherein the input shaft is coupled to a pump shaft of the hydraulic continuously variable transmission be rotatable in unison with each other, the input shaft being coaxially aligned with the pump shaft, and wherein a sun gear of the planetary power transmission section and the output rotary member are supported to be rotatable about a rotation axis extending coaxial with a motor shaft of the hydraulic continuously variable transmission. ### Claim 3 (depends on 1) The shift power transmission apparatus according to claim 1, further comprising: an input-side clutch mechanism switching the planetary power transmission section between an interlocking-on state and an interlocking-off state with respect to the input shaft; and an output-side clutch mechanism switching the output rotary member between an interlocking-on state and an interlocking-off state with respect to the motor shaft of the hydraulic continuously variable transmission. ### Claim 4 (depends on 1) The shift power transmission apparatus according to claim 1, further comprising: a charge pump supplying hydraulic oil to the hydraulic continuously variable transmission, the charge pump being provided between the engine-coupled side and the hydraulic continuously variable transmission-coupled side of the input shaft. ### Claim 5 (depends on 3) The shift power transmission apparatus according to claim 3, further comprising: a charge pump supplying hydraulic oil to the hydraulic continuously variable transmission, the charge pump being provided between the engine-coupled side of the input shaft and an input-side clutch mechanism. ### Claim 6 A shift power transmission apparatus comprising: an input shaft receiving engine drive force; a hydraulic continuously variable transmission driven by the input shaft; a planetary power transmission section combining the drive force from the input shaft and an output from the hydraulic continuously variable transmission for outputting the combined drive force therefrom; and an output rotary member outputting power to a travel apparatus, wherein a forward/reverse switching mechanism is provided to be switchable between a forward power transmission state for converting the drive force from the input shaft into forward drive force to be transmitted to the planetary power transmission section, and a reverse power transmission state for converting the drive force from the input shaft into reverse drive force to be transmitted to the planetary power transmission section, and the forward/reverse switching mechanism is further switchable to a neutral state in which power transmission between the input shaft and the planetary power transmission section is cut off; and wherein a clutch mechanism is provided for switching interlock from the motor shaft of the hydraulic continuously variable transmission to the output rotary member between an on state and an off state. ### Claim 7 (depends on 6) The shift power transmission apparatus according to claim 6, wherein in the on state of the clutch mechanism, a sun gear, a planet gear and a ring gear of the planetary power transmission section are interlocked with the motor shaft of the hydraulic continuously variable transmission to be rotatable with the motor shaft. ### Claim 8 (depends on 6) The shift power transmission apparatus according to claim 6, wherein the forward/reverse switching mechanism includes: a forward power transmission gear supported on the input shaft to be rotatable relative thereto, the forward power transmission gear being interlocked with the planetary power transmission section; a forward clutch member supported on the input shaft to be rotatable in unison therewith and slidable relative thereto for switching the forward power transmission gear and the input shaft between an interlocking-on state and an interlocking-off state in association with engagement with and disengagement from the forward power transmission gear; a reverse power transmission shaft supporting one of the input gear interlocked with the input shaft and the reverse power transmission gear interlocked with the planetary power transmission section to be rotatable relative thereto, and the reverse power transmission shaft supporting thereon the other of the input gear and the reverse power transmission gear to rotatable in unison therewith; and a reverse clutch member supported on the reverse power transmission shaft to be rotatable in unison therewith and slidable relative thereto, wherein when the reverse clutch member is engaged with and disengaged from the one of the input gear and the reverse power transmission gear, which one gear is supported on the reverse power transmission shaft to be rotatable relative thereto to be clutched by the reverse clutch member, the reverse clutch member switches the one gear and the reverse power transmission shaft between an interlocking-on state and an interlocking-off state. ### Claim 9 (depends on 8) The shift power transmission apparatus according to claim 8, wherein the input gear, and a power transmission gear supported on the input shaft to be rotatable in unison and mesh therewith, are arranged on a side of the planetary power transmission section opposite from the forward power transmission gear and the reverse power transmission gear, and wherein the forward power transmission gear and the reverse power transmission gear are meshed with a second input gear provided at a portion of the sun gear of the planetary power transmission section opposite from the input gear and the power transmission gear. ### Claim 10 A travel power transmission apparatus comprising: a shift power transmission device including a hydrostatic continuously variable shift section and a planetary power transmission section; the hydrostatic continuously variable shift section receiving drive force from an engine and outputting the drive force after changing speed of the drive force along an HST shift line by the continuously variable shift section; and the planetary power transmission section receiving and combining the drive force from the engine and the speed-changed drive force from the continuously variable shift section, and outputting the combined drive force after changing speed of the combined drive force along an HMT shift line by the continuously variable shift section; the shift power transmission device further including a clutch mechanism switchable between an HST setting state in which HST power transmission is set for outputting the speed-changed drive force from the continuously variable shift section to a travel apparatus, and an HMT setting state in which HMT power transmission is set for outputting the combined drive force from the planetary power transmission section is outputted to the travel apparatus; and a shift control module for performing shift control on a hydraulic pump of the continuously variable shift section and switch control on the clutch mechanism, based on a shift instruction from a shift operation device, wherein the travel power transmission apparatus further comprises: a swash plate angle sensor detecting a swash plate angle of the hydraulic pump; and a shift swash plate angle setting module for setting, as a set shift swash plate angle of the hydraulic pump, the swash plate angle between a no-load swash plate angle and a load swash plate angle, wherein the no-load swash plate angle is achieved by the hydraulic pump in a shift state for outputting speed-changed drive force at a speed corresponding to an in-unison rotation achievement speed at which the continuously variable shift section achieves in-unison rotation of a sun gear, a carrier and a ring gear of the planetary power transmission section during the HST power transmission and no-load driving, and wherein the load swash plate angle is achieved by the hydraulic pump in a shift state for outputting the speed-changed drive force at a speed corresponding to the in-unison rotation achievement speed of the continuously variable shift section during the HST power transmission and set load driving; and wherein the shift control module is configured to control the clutch mechanism to be switched from the HST setting state to the HMT setting state when the swash plate angle sensor detects the swash plate angle equal to the set shift swash plate angle. ### Claim 11 (depends on 10) The travel power transmission apparatus according to claim 10, wherein the shift swash plate angle setting module has an adjustable configuration such that the setting of the set shift swash plate angle can be changed. ### Claim 12 (depends on 10) The travel power transmission apparatus according to claim 10, wherein the shift swash plate angle setting module is configured to: calculate and set a calculated HST shift line for the HST power transmission and the load driving based on detection information from the swash plate angle sensor, calculate and set a calculated HMT shift line corresponding to the calculated HST shift line, determine the swash plate angle achieved by the hydraulic pump in a shift state in which the continuously variable shift section outputs the speed-changed drive force at a speed corresponding to an intersection between the calculated HST shift line and the calculated HMT shift line, and set the determined swash plate angle as the set shift swash plate angle. ### Claim 13 A travel power transmission apparatus comprising: a shift power transmission device including a hydrostatic continuously variable shift section and a planetary power transmission section; the hydrostatic continuously variable shift section receiving drive force from an engine and outputting the drive force after changing speed of the drive force along an HST shift line by the continuously variable shift section; and the planetary power transmission section receiving and combining the drive force from the engine and the speed-changed drive force from the continuously variable shift section, and outputting the combined drive force after changing speed of the combined drive force along an HMT shift line by the continuously variable shift section; the shift power transmission device further including a clutch mechanism switchable between an HST setting state in which HST power transmission is set for outputting the speed-changed drive force from the continuously variable shift section to a travel apparatus, and an HMT setting state in which HMT power transmission is set for outputting the combined drive force from the planetary power transmission section is outputted to the travel apparatus; and a shift control module for performing shift control on a hydraulic pump of the continuously variable shift section and switch control on the clutch mechanism, based on a main shift instruction from a main shift operation device, wherein a hydraulic motor of the continuously variable shift section is provided in form of a variable displacement motor, the travel power transmission apparatus further comprises an auxiliary shift operation device which is manually operable to issue an auxiliary shift instruction, and an auxiliary shift actuator operable to change a swash plate angle of the hydraulic motor, the shift control module is configured to control the auxiliary shift actuator such that the hydraulic motor is shifted to a higher speed side based on the auxiliary shift instruction, and wherein the travel power transmission apparatus further comprises a restraint control module, the restraint control module being configured such that: when the shift power transmission device is set to the HMT power transmission, and when a power transmission state is achieved in which the combined drive force to be outputted to the travel apparatus is increased in response to a speed-increase shift operation in a reverse shift range of the continuously variable shift section, and in which the combined drive force to be outputted to the travel apparatus is decreased in response to a speed-decrease shift operation in the reverse shift range of the continuously variable shift section, the restraint control module cancels restraint to permit control on the auxiliary shift actuator by the shift control module; and when the shift power transmission device is set to the HMT power transmission, and when a power transmission state is achieved in which the combined drive force to be outputted to the travel apparatus is increased in response to a speed-decrease shift operation in the forward shift range of the continuously variable shift section, and in which the combined drive force to be outputted to the travel apparatus is decreased in response to a speed-increase shift operation in the forward shift range of the continuously variable shift section, the restraint control module performs restraint to stop control on the auxiliary shift actuator by the shift control module. ### Claim 14 (depends on 13) The travel power transmission apparatus according to claim 13, further comprising: a reference swash plate angle setting module configured to set, as a reference swash plate angle, a swash plate angle of the hydraulic pump located on a lower speed side by a set angle relative to the swash plate angle at which the HST power transmission is switched to the HMT power transmission, wherein when the shift power transmission device is set to the HST power transmission, and when the swash plate angle of the hydraulic pump is on the low speed side relative to the reference swash plate angle, the restraint control module cancels the restraint, and wherein when the shift power transmission device is set to the HST power transmission, and when the swash plate angle of the hydraulic pump is on the high speed side relative to the reference swash plate angle, the restraint control module performs the restraint. ### Claim 15 (depends on 13) The travel power transmission apparatus according to claim 13, wherein when the restraint control module performs the restraint, the shift control module is configured to perform shift control on the hydraulic pump based on the main shift instruction and the auxiliary shift instruction such that the output speed of the shift power transmission device corresponding to the main shift instruction will increase in accordance with the auxiliary shift instruction.