Transmission structure

Patent metadata

Field	Value
Publication number	US-2025305569-A1
Application number	US-202519082834-A
Country	US
Kind code	A1
Filing date	Mar 18, 2025
Priority date	Mar 27, 2024
Publication date	Oct 2, 2025
Grant date	—

Abstract

[Problem] To provide a transmission structure that includes a main transmission unit performing continuous speed changing and an auxiliary transmission unit performing multi-stage gear shifting and that can prevent a shock at the time of switching a gear stage of the auxiliary transmission unit during travel as much as possible. [Solution] In the present invention, the controller is configured as follows. When a gear stage switching manipulation is performed by an auxiliary speed change manipulation member during the travel, the controller disengages a pre-switching engagement clutch mechanism in the auxiliary transmission unit to realize an idle running state, operates a speed change output device during the idle running state by setting, as a target, a vehicle speed that corresponds to an actual vehicle speed in a case where an engagement state of a post-switching engagement clutch mechanism is set as a reference, thereafter engages the post-switching engagement clutch mechanism, and controls the operation of the speed change output device by setting, as a target vehicle speed, a vehicle speed that is defined by a manipulation position of a main speed change manipulation member.

First claim

1 . A transmission structure that continuously changes reference rotary power of a drive shaft operatively coupled to a drive source and transmits the changed reference rotary power to a travel output shaft defining a vehicle speed, the transmission structure comprising:
a main transmission unit that has a speed change output device outputting transmission rotary power continuously changed at least between a first-speed stage and a second-speed stage and a planetary gear mechanism combining the reference rotary power and the transmission rotary power and that outputs combined output of the planetary gear mechanism as travel rotary power; an auxiliary transmission unit that can change the travel rotary power from the main transmission unit in multiple stages and transmit the changed travel rotary power to the travel output shaft, the auxiliary transmission unit including a low-speed stage transmission path and a high-speed stage transmission path, through which the travel rotary power from the main transmission unit is transmitted to the travel output shaft at a forward-side low-speed gear ratio and a forward-side high-speed gear ratio, respectively, and low-speed stage and high-speed stage clutch mechanisms that respectively engage/disengage the low-speed stage and high-speed stage transmission paths; a main speed change manipulation member and an auxiliary speed change manipulation member for manipulating the main transmission unit and the auxiliary transmission unit, respectively; and a controller, wherein the controller controls operation of the auxiliary transmission unit to realize a low-speed stage state by engagement of the low-speed stage clutch mechanism and a high-speed stage state by engagement of the high-speed stage clutch mechanism according to a manipulation of the auxiliary speed change manipulation member, and controls operation of the main transmission unit to obtain a target vehicle speed that is defined by a manipulation position of the main speed change manipulation member for each of the low-speed stage state and the high-speed stage state, and the controller further: when a switching manipulation of a gear stage is performed by the auxiliary speed change manipulation member in a state where the travel output shaft is rotationally driven, realizes an idle running state by shifting a pre-switching engagement clutch mechanism, which has been engaged before the switching manipulation by the auxiliary speed change manipulation member, of the low-speed stage and high-speed stage clutch mechanisms, to a disengaged state, and controls operation of the speed change output device to obtain a vehicle speed that corresponds to an actual vehicle speed at the time in a post-switching gear state realized by a post-switching engagement clutch mechanism, which should be engaged after the switching manipulation by the auxiliary speed change manipulation member, of the low-speed stage and high-speed stage clutch mechanisms, during the idle running state; and thereafter shifts the post-switching engagement clutch mechanism to an engaged state, and, in the post-switching gear state, controls the operation of the speed change output device by setting the vehicle speed that is defined by the manipulation position of the main speed change manipulation member at the time as the target vehicle speed.

2 . A transmission structure that continuously changes reference rotary power of a drive shaft operatively coupled to a drive source and transmits the changed reference rotary power to a travel output shaft defining a vehicle speed, the transmission structure comprising:
a main transmission unit that has a speed change output device outputting transmission rotary power continuously changed at least between a first-speed stage and a second-speed stage and a planetary gear mechanism combining the reference rotary power and the transmission rotary power and that outputs combined output of the planetary gear mechanism as travel rotary power; an auxiliary transmission unit that can change the travel rotary power from the main transmission unit in multiple stages and transmit the changed travel rotary power to the travel output shaft, the auxiliary transmission unit including a low-speed stage transmission path and a high-speed stage transmission path, through which the travel rotary power from the main transmission unit is transmitted to the travel output shaft at a forward-side low-speed gear ratio and a forward-side high-speed gear ratio, respectively, and low-speed stage and high-speed stage clutch mechanisms that respectively engage/disengage the low-speed stage and high-speed stage transmission paths; a main speed change manipulation member and an auxiliary speed change manipulation member for manipulating the main transmission unit and the auxiliary transmission unit, respectively; and a controller, wherein the main transmission unit can select between a first-speed stage transmission state and a second-speed stage transmission state, where in the first-speed stage transmission state, a speed of the combined output of the planetary gear mechanism being increased as the transmission rotary power is shifted from the first-speed stage side toward the second-speed stage side; and, in the second-speed stage transmission state, the highest speed in the first-speed stage transmission state is set as the lowest speed, and the speed of the combined output of the planetary gear mechanism is increased as the transmission rotary power is shifted from the second-speed stage side to the first-speed stage side, the controller controls operation of the auxiliary transmission unit to realize a low-speed stage state by engagement of the low-speed stage clutch mechanism and a high-speed stage state by engagement of the high-speed stage clutch mechanism according to a manipulation of the auxiliary speed change manipulation member, and the controller further: realizes a first-speed stage transmission state when the vehicle speed in the low-speed stage state does not exceed a low-speed stage switching speed or the vehicle speed in the high-speed stage state does not exceed a high-speed stage switching speed; realizes the second-speed stage transmission state when the vehicle speed in the low-speed stage state exceeds the low-speed stage switching speed or the vehicle speed in the high-speed stage state exceeds the high-speed stage switching speed; controls operation of the main transmission unit by setting the vehicle speed that is defined by a manipulation position of the main speed change manipulation member as a target vehicle speed for each of the low-speed stage state and the high-speed stage state; in the case where a switching manipulation of a gear stage is performed by the auxiliary speed change manipulation member when the travel output shaft is rotationally driven and the vehicle speed is equal to or lower than the low-speed stage switching speed, realizes an idle running state by shifting a pre-switching engagement clutch mechanism, which has been engaged before the switching manipulation by the auxiliary speed change manipulation member, of the low-speed stage and high-speed stage clutch mechanisms, to a disengaged state, and controls operation of the speed change output device to obtain a vehicle speed that corresponds to an actual vehicle speed at the time in a post-switching gear state realized by a post-switching engagement clutch mechanism, which should be engaged after the switching manipulation by the auxiliary speed change manipulation member, of the low-speed stage and high-speed stage clutch mechanisms, during the idle running state; and thereafter shifts the post-switching engagement clutch mechanism to an engaged state, and, in the post-switching gear state, controls the operation of the speed change output device by setting the vehicle speed that is defined by the manipulation position of th

Assignees

• Kanzaki Kokyukoki Mfg Co Ltd
• Yanmar Holdings Co Ltd

Inventors

• Takahashi Takumi
• Ogura Kohei
• Inoue Tasuku

Classifications

• F16H3/44

  using gears having orbital motion · CPC title

• F16H61/702 Primary

  using electric or electrohydraulic control means · CPC title

• F16H59/44

  dependent on machine speed {, e.g. the vehicle speed} (F16H59/46 takes precedence) · CPC title

• F16H2037/0886

  with switching means, e.g. to change ranges · CPC title

• F16H47/04 Primary

  the mechanical gearing being of the type with members having orbital motion · CPC title