US 12,247,630 B2Granted

Hydraulic clutch, travel power transmission device, and work vehicle

AssigneeKubota Corporation

InventorsAtsushi Jinnai, Tomonari Tsuchida, Ryoma Iwase, Tomoyuki Tanaka, Yoshiki Fujiyama, Koki Date

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Abstract

A hydraulic clutch includes friction plates to transmit motive power, a piston movable between (i) a pressing position, at which the piston presses the friction plates for the hydraulic clutch to be engaged to transmit motive power, and (ii) a separated position, at which the piston is spaced apart from the friction plates for the hydraulic clutch to be disengaged to block motive power, the piston being movable into the pressing position in response to receiving hydraulic fluid to move the piston toward the pressing position, and a holder to (i) hold the piston at an intermediate position between the pressing position and the separated position in response to the piston coming into contact with the holder and (ii) release the piston from the intermediate position.

Claims15

Dependent claims

A hydraulic clutch, comprising:

friction plates to transmit motive power;
a piston movable between (i) a pressing position, at which the piston presses the friction plates for the hydraulic clutch to be engaged to transmit motive power, and (ii) a separated position, at which the piston is spaced apart from the friction plates for the hydraulic clutch to be disengaged to block motive power, the piston being movable into the pressing position in response to receiving hydraulic fluid to move the piston toward the pressing position;
and
a holder to (i) hold the piston at an intermediate position between the pressing position and the separated position in response to the piston coming into contact with the holder and (ii) release the piston from the intermediate position;
wherein
the holder is movable between (i) a holding position, at which the holder holds the piston at the intermediate position, and (ii) an allowing position, which is closer to the friction plates relative to the holding position and at which the holder allows the piston to be moved into the pressing position;
the hydraulic clutch further comprises:
a first urging structure to urge the holder toward the holding position;
and
a second urging structure to urge the piston toward the pressing position with an urging force smaller than an urging force of the first urging structure;
and
the holder is operable to hold the piston at the intermediate position in response to the piston being urged by the second urging structure toward the pressing position coming into contact with the holder that is being urging by the first urging structure into the holding position.

9 more elements

A travel power transmission device, comprising:

a plurality of power transmission systems configured for respective speed change steps with respective power transmission rates different from each other;
and
a plurality of power transmission clutches for the respective power transmission systems, each power transmission clutch of the plurality of power transmission clutches including:
friction plates to transmit motive power;
and
a piston movable between (i) a pressing position, at which the piston presses the friction plates for the power transmission clutch to be engaged to transmit motive power, and (ii) a separated position, at which the piston is spaced apart from the friction plates for the power transmission clutch to be disengaged to block motive power, the piston being movable into the pressing position in response to receiving hydraulic fluid to move the piston toward the pressing position;
wherein
at least one of the plurality of power transmission clutches is a hydraulic clutch that includes a holder to (i) hold the piston at an intermediate position between the pressing position and the separated position in response to the piston coming into contact with the holder and (ii) release the piston from the intermediate position;
at least one of the plurality of power transmission systems includes at least one speed change step within a low-speed region and at least one speed change step within a high-speed region;
the power transmission clutch provided in the at least one of the plurality of power transmission systems for the at least one speed change step within the low-speed region is the hydraulic clutch;
the pressing position and the separated position are separated from each other by a gap that is smaller for the power transmission clutch of a power transmission system among the plurality of power transmission systems which power transmission system is configured for the at least one speed change step within the high-speed region than for the hydraulic clutch of the power transmission system configured for the at least one speed change step within the low-speed region.

8 more elements

A travel power transmission device, comprising:

a plurality of power transmission systems configured for respective speed change steps with respective power transmission rates different from each other;
and
a plurality of power transmission clutches for the respective power transmission systems, each power transmission clutch of the plurality of power transmission clutches including:
friction plates to transmit motive power;
and
a piston movable between (i) a pressing position, at which the piston presses the friction plates for the power transmission clutch to be engaged to transmit motive power, and (ii) a separated position, at which the piston is spaced apart from the friction plates for the power transmission clutch to be disengaged to block motive power, the piston being movable into the pressing position in response to receiving hydraulic fluid to move the piston toward the pressing position;
and
an operation section;
wherein
at least one of the plurality of power transmission clutches is a hydraulic clutch that includes a holder to (i) hold the piston at an intermediate position between the pressing position and the separated position in response to the piston coming into contact with the holder and (ii) release the piston from the intermediate position;
the operation section is operable to cause the holder of the hydraulic clutch to hold the piston of the hydraulic clutch at the intermediate position in response to engagement of the power transmission clutch of a power transmission system among the plurality of power transmission systems of which power transmission system the power transmission rate is next to the power transmission rate of a power transmission system among the plurality of power transmission systems which power transmission system includes the hydraulic clutch;
and
the operation section is operable to:
(i) in response to engagement of the power transmission clutch of a power transmission system among the plurality of power transmission systems which power transmission system is configured for a lowest speed step among the speed change steps, cause the holder of the hydraulic clutch to hold the piston of the hydraulic clutch at the intermediate position, the hydraulic clutch being of a power transmission system among the plurality of power transmission systems which power transmission system is configured for a speed change step next to the lowest speed step on a high-speed side;
and
(ii) in response to engagement of the power transmission clutch of a power transmission system among the plurality of power transmission systems which power transmission system is configured for a speed change step on the high-speed side of the power transmission system configured for the lowest speed step, cause the holder of the hydraulic clutch to hold the piston of the hydraulic clutch at the intermediate position, the hydraulic clutch being of a power transmission system among the plurality of power transmission systems which power transmission system is configured for a speed change step next, on a low-speed side, to the speed change step of the power transmission system of which the power transmission clutch is engaged.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/740,571Filed 12 Jun 2024
Priority: JP 2023-10282522 Jun 2023
Published: US 2024/0426351 A126 Dec 2024
Granted: 11 Mar 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

F16D 43/284
Actuated by fluid pressure: controlled by angular speed
F16D 25/0638
With flat friction surfaces, e.g. discs: with more than two discs, e.g. multiple lamellae
F16D 13/52
With flat clutching surfaces, e.g. discs: clutches with multiple lamellae ; Clutches in which three or more axially moveable members are fixed…
F16D 13/69
Clutch-plates; Clutch-lamellae: arrangements for spreading lamellae in the released state