# US 12,000,343 B1 · Pressure balancing of rotating control piston of generator transmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,000,343 B1 - Document ID: US12000343B1 - Status: Granted - Kind: B1 - Application number: 18/295,587 - Filed: 2023-04-04 - Granted: 2024-06-04 - Earliest claimed: 2023-04-04 - Assignees: Hamilton Sundstrand Corporation - Applicants: Hamilton Sundstrand Corporation - Inventors: Aaron Cooling; Glenn C. Lemmers, Jr. - Web page: https://patentgrep.com/patent/US12000343B1 ## CPC - F02C 7/32: Arrangement, mounting, or driving, of auxiliaries - B64D 27/10: of gas-turbine type (jet aircraft B64D27/16) - B64D 35/00: Transmitting power from power plants to propellers or rotors; Arrangements of transmissions - F01D 15/10: Adaptations for driving, or combinations with, electric generators - F16D 13/52: Clutches with multiple lamellae {; Clutches in which three or more axially moveable members are fixed alternately to the shafts to be coupled and are pressed from one side towards an axially-located member (F16D13/385 takes precedence)} - F16D 25/0638: with more than two discs, e.g. multiple lamellae - F16D 25/14: {Fluid pressure control} - F16D 48/02: Control by fluid pressure - F05D 2220/76: an electrical generator - F05D 2260/4023: through a friction clutch - F16D 2048/0212: {Details of pistons for primary or secondary cylinders especially adapted for fluid control} - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A clutch assembly includes a clutch pack, and a rotating control piston selectably engageable with the clutch pack via movement of the clutch piston along an axis of rotation of the control piston. The clutch piston includes a piston member engageable with the clutch pack, a cover plate installed into the piston member to define an enclosed volume, and an axially fixed chamber divider positioned in the enclosed volume to divide the enclosed volume into a control pressure chamber and a pressure balancing chamber. Both the control pressure chamber and the pressure balancing chamber are filled with hydraulic fluid, and the control piston is moved between a disengaged position and an engaged position via modulation of hydraulic pressure in the control pressure chamber. ## Claims ### Claim 1 A clutch assembly, comprising: a clutch pack; a rotating control piston selectably engageable with the clutch pack via movement of the control piston along an axis of rotation of the control piston, the control piston including: a piston member engageable with the clutch pack; a cover plate installed into the piston member to define an enclosed volume; an axially fixed chamber divider disposed in the enclosed volume to divide the enclosed volume into a control pressure chamber and a pressure balancing chamber; wherein both the control pressure chamber and the pressure balancing chamber are filled with hydraulic fluid; and wherein the control piston is moved between a disengaged position and an engaged position via modulation of hydraulic pressure in the control pressure chamber; and a plurality of control pressure orifices fluidly connected to the control pressure chamber through which hydraulic fluid enters and exits the control pressure chamber. ### Claim 2 (depends on 1) The clutch assembly of claim 1, further comprising a plurality of pressure balance chamber orifices fluidly connected to the pressure balance chamber through which hydraulic fluid enters and exits the pressure balance chamber. ### Claim 3 (depends on 1) The clutch assembly of claim 1, further comprising one or more glide rings between the chamber divider and a radially outer wall of the piston member. ### Claim 4 (depends on 1) The clutch assembly of claim 1, wherein the chamber divider is operably connected to an output shaft. ### Claim 5 (depends on 4) The clutch assembly of claim 4, wherein the chamber divider is formed integral to the output shaft. ### Claim 6 (depends on 1) The clutch assembly of claim 1, further comprising a retaining ring to retain the cover plate inside the piston member. ### Claim 7 A speed changing transmission assembly, comprising: an input shaft: an output shaft; and one or more clutch assemblies to selectably engageable with the output shaft, each clutch assembly including: a clutch pack; a rotating control piston selectably engageable with the clutch pack via movement of the control piston along an axis of rotation of the control piston, the control piston including: a piston member engageable with the clutch pack; a cover plate installed into the piston member to define an enclosed volume; an axially fixed chamber divider disposed in the enclosed volume to divide the enclosed volume into a control pressure chamber and a pressure balancing chamber; wherein both the control pressure chamber and the pressure balancing chamber are filled with hydraulic fluid; and wherein the control piston is moved between a disengaged position and an engaged position via modulation of hydraulic pressure in the control pressure chamber; and wherein the control pressure chamber and the pressure balancing chamber are configured to exert equal and opposite forces on the rotating control piston due to balancing of centripetal forces attributable to the rotation of each hydraulic fluid-filled chamber. ### Claim 8 (depends on 7) The transmission assembly of claim 7, further comprising a plurality of control pressure orifices fluidly connected to the control pressure chamber through which hydraulic fluid enters and exits the control pressure chamber. ### Claim 9 (depends on 7) The transmission assembly of claim 7, further comprising a plurality of pressure balance chamber orifices fluidly connected to the pressure balance chamber through which hydraulic fluid enters and exits the pressure balance chamber. ### Claim 10 (depends on 7) The transmission assembly of claim 7, further comprising one or more glide rings disposed between the chamber divider and a radially outer wall of the piston member. ### Claim 11 (depends on 7) The transmission assembly of claim 7, wherein the chamber divider is operably connected to the output shaft. ### Claim 12 (depends on 11) The transmission assembly of claim 11, wherein the chamber divider is formed integral to the output shaft. ### Claim 13 (depends on 7) The transmission assembly of claim 7, further comprising a retaining ring to retain the cover plate inside the piston member. ### Claim 14 An aircraft, comprising: a gas turbine engine; one or more accessory components operably connected to the gas turbine engine, and driven by rotational energy diverted from the gas turbine engine; a speed-changing transmission assembly configured to convert the rotational energy diverted from the gas turbine engine to a speed range usable by the one or more accessory components, the transmission assembly including: an input shaft operably connected to the gas turbine engine: an output shaft operably connected to the one or more accessory components; and one or more clutch assemblies to selectably engageable with the output shaft, each clutch assembly including: a clutch pack; a rotating control piston selectably engageable with the clutch pack via movement of the control piston along an axis of rotation of the control piston, the control piston including: a piston member engageable with the clutch pack; a cover plate installed into the piston member to define an enclosed volume; an axially fixed chamber divider disposed in the enclosed volume to divide the enclosed volume into a control pressure chamber and a pressure balancing chamber; wherein both the control pressure chamber and the pressure balancing chamber are filled with hydraulic fluid; and wherein the control piston is moved between a disengaged position and an engaged position via modulation of hydraulic pressure in the control pressure chamber; and a plurality of control pressure orifices fluidly connected to the control pressure chamber through which hydraulic fluid enters and exits the control pressure chamber. ### Claim 15 (depends on 14) The aircraft of claim 14, further comprising a plurality of pressure balance chamber orifices fluidly connected to the pressure balance chamber through which hydraulic fluid enters and exits the pressure balance chamber. ### Claim 16 (depends on 14) The aircraft of claim 14, wherein the chamber divider is operably connected to the output shaft. ### Claim 17 (depends on 14) The aircraft of claim 14, wherein the input shaft diverts the rotational energy from a low speed spool of the gas turbine engine. ### Claim 18 (depends on 14) The aircraft of claim 14, wherein the one or more accessory components includes a generator. ### Claim 19 (depends on 2) The clutch assembly of claim 2, wherein a hydraulic fluid pressure in the pressure balancing chamber is modulated via the plurality of pressure balancing orifices. ### Claim 20 (depends on 9) The transmission assembly of claim 9, wherein a hydraulic fluid pressure in the pressure balancing chamber is modulated via the plurality of pressure balancing orifices.