# US 2024/0200614 A1 · Hydraulic clutch and work-vehicle travel power transmission apparatus including the hydraulic clutch > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0200614 A1 - Document ID: US20240200614A1 - Status: Published application - Kind: A1 - Application number: 18/537,175 - Filed: 2023-12-12 - Published: 2024-06-20 - Earliest claimed: 2022-12-16 - Assignees: Kubota Corporation - Applicants: Kubota Corporation - Inventors: Hidetoshi HANA; Atsushi JINNAI; Tomonari TSUCHIDA; Ryoma IWASE; Yosui NISHIJIMA; Naoyuki MIYAMOTO - Web page: https://patentgrep.com/patent/US20240200614A1 ## CPC - F16D 25/123: {in view of cooling and lubrication} - F16D 25/0638: with more than two discs, e.g. multiple lamellae - F16D 25/10: Clutch systems with a plurality of fluid-actuated clutches (arrangements or mounting of clutches in vehicles B60K17/00) - F16D 2021/0607: {Double clutch with torque input plate in-between the two clutches, i.e. having a central input plate} - F16D 2021/0661: {Hydraulically actuated multiple lamellae clutches} - F16D 2048/0212: {Details of pistons for primary or secondary cylinders especially adapted for fluid control} - F16D 2125/06: Pistons - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES ## Abstract A clutch hub includes oil supply holes extending therethrough to supply lubricating oil from an interior of the clutch hub toward first clutch plates and second clutch plates. An injection port to allow injection of the lubricating oil into the interior of the clutch hub is located inside of the clutch hub between the clutch hub and a rotation axis of a clutch body. The clutch hub includes an inner circumferential portion including an opposing portion opposing the injection port, and a first portion closer to a first end portion of the clutch hub than the opposing portion in a direction extending along the rotation axis. The first portion includes an inclined inner circumferential surface structured such that a radius of the clutch hub decreases toward the first end portion. ## Claims ### Claim 1 A hydraulic clutch comprising: a clutch body; a tubular clutch hub located inside a tubular clutch plate support section included in the clutch body; a plurality of first clutch plates to be locked to the clutch plate support section and arranged in a direction extending along a rotation axis of the clutch body; a plurality of second clutch plates to be locked to the clutch hub and arranged in the direction extending along the rotation axis; oil supply holes extending through the clutch hub to supply lubricating oil from an interior of the clutch hub toward the first clutch plates and the second clutch plates; and an injection port to allow injection of the lubricating oil into the interior of the clutch hub; wherein the injection port is located in the interior of the clutch hub at a location between the clutch hub and the rotation axis; and the clutch hub includes an inner circumferential portion including: an opposing portion opposing the injection port; and a first portion closer to a first end portion of the clutch hub than the opposing portion in the direction extending along the rotation axis, the first portion including an inclined inner circumferential surface structured such that a radius of the clutch hub decreases toward the first end portion. ### Claim 2 (depends on 1) The hydraulic clutch according to claim 1, wherein the opposing portion includes a parallel inner circumferential surface that is parallel or substantially parallel to the rotation axis. ### Claim 3 (depends on 1) The hydraulic clutch according to claim 1, wherein the injection port is located in the interior of the clutch hub at a location opposing a portion between opposite end portions of the clutch hub in the direction extending along the rotation axis; and the inner circumferential portion of the clutch hub further includes a second portion closer to a second end portion of the clutch hub than the opposing portion in the direction extending along the rotation axis, the second portion including an inclined inner circumferential surface structured such that the radius of the clutch hub decreases toward. ### Claim 4 (depends on 1) The hydraulic clutch according to claim 1, wherein the clutch plate support section includes an oil discharge hole extending therethrough to discharge the lubricating oil out from an interior of the clutch body. ### Claim 5 (depends on 1) The hydraulic clutch according to claim 1, wherein the oil supply holes are arranged with intervals therebetween in a circumferential direction of the clutch hub respectively at a plurality of locations of the clutch hub in the direction extending along the rotation axis. ### Claim 6 (depends on 5) The hydraulic clutch according to claim 5, wherein the oil supply hole at one of two adjacent locations and the oil supply hole at another one of the two adjacent locations are displaced from each other in the circumferential direction of the clutch hub. ### Claim 7 (depends on 1) The hydraulic clutch according to claim 1, wherein the clutch body includes, in the interior thereof: a clutch piston to press and release the first clutch plates and the second clutch plates; a return spring to return the clutch piston to a release position; and a stopper to receive and support the return spring; the stopper includes an inserted portion inserted into the interior of the clutch hub; and the injection port extends through the inserted portion. ### Claim 8 (depends on 1) A work-vehicle travel power transmission apparatus comprising: a forward/rearward travel switch including two of the hydraulic clutches according to claim 1; and a transmission to shift power supplied from a power source and output the power to the forward/rearward travel switch; wherein in response to one of the two hydraulic clutches being engaged, the forward/rearward travel switch is operable to convert power supplied from the transmission into forward travel power and output the forward travel power toward a travel device, and, in response to the other of the two hydraulic clutches being engaged, convert power supplied from the transmission into rearward travel power and output the rearward travel power toward the travel device.