Hydrostatic transmission with interconnected swash plate neutral valve and brake unit
AssigneeKanzaki Kokyukoki Mfg. Co., Ltd.
InventorHideaki Okada
Life of this patent
Estimating the term…
Abstract
A hydrostatic transmission system axle driving apparatus for changing the speed of a vehicle which includes a hydraulic pump, hydraulic motor and braking unit. Neutral valves at an open position are automatically returned to a closed position with the operation of a brake controller. This allows the vehicle to be started at slow speed, but not abruptly.
Claims12
A hydrostatic transmission system axle driving apparatus which connects a hydraulic pump in association with an engine and a hydraulic motor in association with axles by a pair of oil passages, comprising:
- neutral valves, which are capable of switching said oil passage at the high pressure side to the "open" position communicating with said oil passage at the low pressure side and to the "closed" position cutting off said communication with said oil passage, at a center section;
- a neutral valve operating member which alternatively switches the positions of said neutral valves through a detent unit, thereby enabling said positions to be held;
- and
- a braking unit on a power transmission route extending from said hydraulic motor to said axles,
- wherein said braking unit and said neutral valves are linked such that when said braking unit is actuated by a brake operating member, said neutral valves, only when held to the "open" positions, are released to be switched to the "closed" position.
A hydrostatic transmission system axle driving apparatus which connects a hydraulic pump in association with an engine and a hydraulic motor in association with axles by a pair of oil passages formed at a center section, wherein said hydraulic pump, said hydraulic motor, and said center section are housed in a transmission case, comprising:
- neutral valves, capable of switching said oil passage at the high pressure side to the "open" position communicating with said oil passage at the low pressure side and to the "closed" position to cut off said communication with said oil passage, at said center section housed in a transmission case;
- a neutral valve operating member which alternatively switches said neutral valves in position through a detent unit, thereby enabling said positions to be held;
- and
- a braking unit on a power transmission route extending from said hydraulic motor to said axles,
- wherein said braking unit and said neutral valves are linked with each other such that said neutral valves, only when held in the "open" position, are released to be switched to the "closed" position.
A hydrostatic transmission system axle driving apparatus which connects a variable displacement hydraulic pump in association with an engine and a hydraulic motor in association with axles by use of a pair of oil passages, comprising:
- neutral valves, capable of switching said oil passage at the high pressure side to the "open" position for communicating with said oil passage at the low pressure side and to the "closed" position cutting off said communication with said oil passage at the low pressure side, at a center section;
- a neutral valve operating member which alternatively switches said neutral valves in position so as to make said positions holdable;
- a swash plate of said variable displacement hydraulic pump constituted to be variable of an angle of said swash plate by a speed change operating member;
- and
- a braking unit,
- wherein said variable displacement hydraulic pump, and said neutral valves, are so linked that, when said brake unit provided on a power transmission route from said hydraulic motor to said axles is actuated by a brake operating member, said swash plate is returned to the neutral, and simultaneously said neutral valves, only when held in the "open" position, are released to be switched to the "closed" position.
Dependencies are inferred from the claim text.