US 11,867,133 B2
Hydraulic static transmission system
Akihiro Kondo, Kobe (JP); Ryosuke Kusumoto, Kobe (JP); and Yuki Nakayama, Kobe (JP)
Assigned to KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe (JP)
Appl. No. 17/785,276
Filed by KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe (JP)
PCT Filed Nov. 26, 2020, PCT No. PCT/JP2020/043946
§ 371(c)(1), (2) Date Jun. 14, 2022,
PCT Pub. No. WO2021/124825, PCT Pub. Date Jun. 24, 2021.
Claims priority of application No. 2019-230263 (JP), filed on Dec. 20, 2019.
Prior Publication US 2023/0022177 A1, Jan. 26, 2023
Int. Cl. F02D 41/00 (2006.01); F02D 41/12 (2006.01); F16H 61/421 (2010.01)
CPC F02D 41/123 (2013.01) [F16H 61/421 (2013.01); F02D 2200/501 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A hydraulic static transmission system for use in traveling of a vehicle, the hydraulic static transmission system comprising:
a variable displacement motor that drives traveling means;
a motor regulator that changes a displacement of the motor;
a variable displacement pump connected to the motor such that a closed loop is formed, the variable displacement pump being driven by an engine;
a pump regulator that changes a displacement of the pump;
a depression amount detector that detects a depression amount of an accelerator pedal;
a vehicle speed detector that detects a vehicle speed of the vehicle;
a rotation number detector that detects a number of rotations of the engine per unit time; and
a controller that controls the motor regulator and the pump regulator, wherein
the controller:
determines whether or not a particular downhill travel condition is satisfied based on a result of detection by the vehicle speed detector and a result of detection by the rotation number detector; and
in a case where the depression amount of the accelerator pedal, which is detected by the depression amount detector, is zero and the particular downhill travel condition is satisfied, controls the motor regulator to increase the displacement of the motor wherein
the particular downhill travel condition includes:
a condition that the vehicle speed detected by the vehicle speed detector is higher than a setting value;
a condition that a derivative value of the vehicle speed is greater than zero; and
a condition that the number of rotations of the engine, which is detected by the rotation number detector, is greater than a setting value.