# US 8,998,564 B2 · Motor-generator connection shaft vent > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,998,564 B2 - Document ID: US8998564B2 - Status: Granted - Kind: B2 - Application number: 13/047,950 - Filed: 2011-03-15 - Published: 2012-09-20 - Granted: 2015-04-07 - Earliest claimed: 2011-03-15 - Assignees: Hamilton Sundstrand Corporation - Applicants: Glenn C. Lemmers, Jr.; David S. Behling; Luke Wagner - Inventors: Glenn C. Lemmers, Jr.; David S. Behling; Luke Wagner - Web page: https://patentgrep.com/patent/US8998564B2 ## CPC - F01D 5/026: {Shaft to shaft connections} - F01D 15/10: Adaptations for driving, or combinations with, electric generators - F05D 2260/608: Aeration, ventilation, dehumidification or moisture removal of closed spaces - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract An example method of reducing loads on a connection shaft includes disengaging a connection shaft from a motor-generator such that the connection shaft is not rotatably coupled to the motor-generator. The method communicates a fluid away from the motor-generator through a communication path established within the connection shaft. An example turbomachine connection shaft is configured to selectively rotatably couple a turbomachine rotor and a motor-generator. The connection shaft establishes a communication path that selectively vents the motor-generator. ## Claims ### Claim 1 A turbomachine connection shaft assembly, comprising: a connection shaft that is configured to selectively rotatably couple a turbomachine rotor and a motor-generator, the connection shaft establishing a communication path that selectively vents a fluid from the motor-generator, the communication path established within the connection shaft. ### Claim 2 (depends on 1) The turbomachine connection shaft assembly of claim 1, wherein the fluid moves from the communication path to a turbine engine having the turbomachine rotor. ### Claim 3 (depends on 1) The turbomachine connection shaft assembly of claim 1, wherein the fluid moves from the communication path to ambient. ### Claim 4 (depends on 1) The turbomachine connection shaft assembly of claim 1, further comprising: an expansion plug disposed within an axially extending bore that is established within the connection shaft, the expansion plug defining an aperture that communicates the fluid from a first axial side of the expansion plug to an opposing, second axial side of the expansion plug. ### Claim 5 (depends on 4) The turbomachine connection shaft assembly of claim 4, wherein the aperture is coaxial with the connection shaft. ### Claim 6 (depends on 4) The turbomachine connection shaft assembly of claim 4, including a dollop of solder that moves from a first position when the connection shaft and the motor-generator are rotatably coupled to a second position when the connection shaft and the motor-generator are rotatably decoupled, the dollop of solder configured to restrict flow through the aperture in the first position and allow flow in the second position. ### Claim 7 (depends on 1) The turbomachine connection shaft assembly of claim 1, including a screened plug disposed within a portion of the communication path, wherein the communication path communicates the fluid to an engine. ### Claim 8 (depends on 1) The turbomachine connection shaft assembly of claim 1, wherein the connection shaft defines at least one hole extending from an axially extending bore to a radially outer surface of the connection shaft. ### Claim 9 (depends on 8) The turbomachine connection shaft assembly of claim 8, wherein the communication path comprises portions of the bore, an aperture, and the hole. ### Claim 10 (depends on 1) The turbomachine connection shaft assembly of claim 1, including a journal shaft that receives an end portion of the connection shaft, the connection shaft configured to rotate the journal shaft, wherein the journal shaft is configured to selectively rotatably couple the connection shaft to the motor-generator. ### Claim 11 (depends on 1) The turbomachine connection shaft assembly of claim 1, wherein the motor-generator is a variable frequency generator. ### Claim 12 A motor-generator assembly, comprising: a motor-generator; and a connection shaft rotatably coupled to a rotor of a gas turbine and selectively rotatably coupled to the motor-generator, wherein the connection shaft establishes a communication path configured to block fluid flow when the connection shaft is coupled to the motor-generator, and to vent the motor-generator when the connection shaft is decoupled from the motor-generator, the communication path established within the connection shaft. ### Claim 13 (depends on 12) The motor-generator assembly of claim 12, including a journal shaft received over one end of the connection shaft, the journal shaft configured to rotate together with the connection shaft. ### Claim 14 (depends on 13) The motor-generator assembly of claim 13, including a radial support bearing arrangement configured to support the connection shaft, wherein the connection shaft rotates with the radial support bearing arrangement when the connection shaft is coupled to the motor-generator, and the journal shaft rotates relative to the radial support bearing when the connection shaft is decoupled from the motor-generator. ### Claim 15 A method of reducing loads on a connection shaft, comprising: disengaging a connection shaft from a motor-generator such that the connection shaft is not rotatably coupled to the motor-generator; and communicating a fluid away from the motor-generator through a communication path established within the connection shaft. ### Claim 16 (depends on 15) The method of claim 15, wherein the disengaging comprises disengaging jaws of a journal shaft with corresponding jaws of the motor-generator. ### Claim 17 (depends on 15) The method of claim 15, wherein the method is performed on an aircraft and the connection shaft is biased axially toward the motor-generator during all stages of flight of the aircraft. ### Claim 18 (depends on 12) The motor-generator assembly of claim 12, including a screened plug disposed within a portion of the communication path. ### Claim 19 (depends on 15) The method of claim 15, including limiting movement of debris along the communication path using a screened plug. ### Claim 20 (depends on 15) The method of claim 15, including blocking the communication path when the connection shaft engages the motor-generator.