# US 2019/0170234 A1 · Electronic limited slip coupling having bolt on configuration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170234 A1 - Document ID: US20190170234A1 - Status: Published application - Kind: A1 - Application number: 16/270,023 - Filed: 2019-02-07 - Published: 2019-06-06 - Earliest claimed: 2016-08-10 - Assignees: Eaton Intelligent Power Limited - Applicants: Eaton Intelligent Power Limited - Inventors: Andrew N. Edler; Randal James Graves; Jeffrey A. Oesch - Web page: https://patentgrep.com/patent/US20190170234A1 ## CPC - F16H 48/34: using electromagnetic or electric actuators - F16H 48/22: using friction clutches or brakes - F16H 57/0473: {Friction devices, e.g. clutches or brakes} - F16H 57/0483: {Axle or inter-axle differentials} - F16H: GEARING ## Abstract An electronic limited slip coupling constructed in accordance to one example of the present disclosure includes a sleeve, a support shaft, a hydraulic control unit, a clutch assembly and a case. The sleeve has a first set of splines projecting inwardly and meshed for engagement with an axle. The support shaft has a second set of splines configured to mesh with a first housing of a differential assembly. The hydraulic control unit has an accumulator housing and a motor. The motor is configured to pump fluid into an accumulator chamber of the accumulator housing. The clutch assembly receives fluid from the hydraulic control unit. The clutch assembly has a clutch pack positioned between a clutch piston and a portion of a clutch basket. The clutch assembly is operable to selectively interlock the sleeve and the support shaft. The case supports the electronic limited slip coupling as an assembled unit. ## Claims ### Claim 1 An electronic limited slip coupling comprising: a sleeve having a first set of splines projecting inwardly and meshed for engagement with an axle; a support shaft having a second set of splines configured to mesh with a first housing of a differential assembly; a hydraulic control unit having: an accumulator housing portion that houses a biasing assembly and an accumulator piston, the accumulator housing portion forming an accumulator chamber with the accumulator piston; and a motor that is configured to pump fluid into the accumulator chamber of the accumulator housing portion; a clutch assembly that receives fluid from the hydraulic control unit, the clutch assembly having a clutch pack positioned between a clutch piston and a portion of a clutch basket, the clutch assembly operable to selectively interlock the sleeve and the support shaft; and a case that supports the electronic limited slip coupling as an assembled unit, the case having a flange that defines apertures for receiving fasteners that threadably couple the electronic limited slip coupling to one of a front transfer case and a front transmission. ### Claim 2 The electronic limited slip coupling wherein the clutch basket is fixed for rotation with the support shaft and at least partially encircling the sleeve. ### Claim 3 (depends on 2) The electronic limited slip coupling of claim 2 wherein the clutch pack includes a first subset of plates fixed for rotation with the sleeve and a second subset of plates fixed for rotation with the clutch basket. ### Claim 4 (depends on 3) The electronic limited slip coupling of claim 3 wherein movement of the clutch piston urges the clutch pack against a portion of the clutch basket. ### Claim 5 (depends on 4) The electronic limited slip coupling of claim 4 wherein the clutch basket and the support shaft are interconnected through a third set of splines defined by the clutch basket and a fourth set of splines defined by the support shaft. ### Claim 6 (depends on 1) The electronic limited slip coupling of claim 1 wherein the fluid pumped into the accumulator housing portion at least partially collapses the biasing assembly and introduces a pre-charge into the hydraulic control unit, wherein the biasing assembly is configured to expand and urge the accumulator piston in a first direction resulting in fluid being communicated from the hydraulic control unit and into the clutch assembly. ### Claim 7 (depends on 1) The electronic limited slip coupling of claim 1 wherein the one of the front transaxle and front transmission is configured for use in one of a front wheel drive vehicle and all-wheel drive vehicle. ### Claim 8 (depends on 1) The electronic limited slip coupling of claim 1, further comprising a second housing that encloses the first housing, wherein the axle extends from a first end inside both of the first housing and the second housing to a second end spaced from an interior cavity of the second housing. ### Claim 9 (depends on 1) The electronic limited slip coupling of claim 1 wherein the sleeve defines a sleeve aperture centered on and extending along an axis defined by the axle. ### Claim 10 An electronic limited slip coupling comprising: an axle shaft that extends along an axle axis and is configured to meshingly engage a side gear of a differential assembly; a sleeve having a first set of splines projecting inwardly and meshed for engagement with the axle shaft; a support shaft having a second set of splines configured to mesh with a first housing of the differential assembly; a hydraulic control unit having: an accumulator housing portion that houses a biasing assembly and an accumulator piston, the accumulator housing portion forming an accumulator chamber with the accumulator piston, wherein the fluid pumped into the accumulator housing portion at least partially collapses the biasing assembly and introduces a pre-charge into the hydraulic control unit, wherein the biasing assembly is configured to expand and urge the accumulator piston in a first direction resulting in fluid being communicated from the hydraulic control unit and into the clutch assembly; and a motor that is configured to pump fluid into the accumulator chamber of the accumulator housing portion; a clutch assembly that receives fluid from the hydraulic control unit, the clutch assembly having a clutch pack operable to selectively interlock the sleeve and the support shaft; and a case that supports the electronic limited slip coupling as an assembled unit, the case having a flange that defines apertures for receiving fasteners that threadably couple the electronic limited slip coupling to one of a front transfer case and a front transmission. ### Claim 11 (depends on 10) The electronic limited slip coupling of claim 10 wherein the clutch pack includes a first subset of plates fixed for rotation with the sleeve and a second subset of plates fixed for rotation with the clutch basket. ### Claim 12 (depends on 11) The electronic limited slip coupling of claim 11 wherein the clutch assembly further comprises a clutch piston that urges the clutch pack against a portion of the clutch basket upon delivery of fluid from the hydraulic control unit. ### Claim 13 (depends on 12) The electronic limited slip coupling of claim 12 wherein the clutch basket and the support shaft are interconnected through a third set of splines defined by the clutch basket and a fourth set of splines defined by the support shaft. ### Claim 14 (depends on 10) The electronic limited slip coupling of claim 10 wherein the one of the front transaxle and front transmission is configured for use in one of a front wheel drive vehicle and all-wheel drive vehicle. ### Claim 15 (depends on 10) The electronic limited slip coupling of claim 10, further comprising a second housing that encloses the first housing, wherein the axle extends from a first end inside both of the first housing and the second housing to a second end spaced from an interior cavity of the second housing. ### Claim 16 (depends on 10) The electronic limited slip coupling of claim 10 wherein the sleeve defines a sleeve aperture centered on and extending along the axle axis.