Abstract: A gas turbine engine is provided that includes a gearbox operable to selectively couple a relatively high pressure spool shaft to a relatively low pressure spool shaft. In one form the gearbox includes a cone clutch that engages a male member of the cone clutch to a female member of the cone clutch during an engine start of the gas turbine engine. A relatively high pressure of a working fluid can be used to bring the male member and the female member together. A spring can also be used to urge the male member and the female member apart when the working fluid is at a relatively low pressure.

Abstract: A multi-plate clutch is provided to couple a drive shaft from a gas turbine engine with a driven shaft of a lift fan. When disengaged the plates of the clutch can be physically separated. Plates of one shaft are coupled to the shaft with individual energy members that return the plates to a disengaged position. The plates of the other shaft can be coupled together with a travel member and/or lug key and energy devices between at least some of the plates.

Abstract: A method for evaluating a lubrication containment system is set forth herein. In one lubrication containment system, a seal runner can be fixed to the rotatable structure and seal against a static radial seal supported by the sump housing. The method also includes the step of rotating the structure relative to the sump housing. The method also includes the step of directing test fluid to the structure inside the sump housing. The method also includes the step of quantifying an accumulation of test lubricant at the seal runner during rotation by omitting the radial seal from the lubrication containment system. As a result, test lubricant can pass out of the sump housing. The amount of test lubricant that passes out of the sump housing, past the location where the seal runner would be or would have been, corresponds to the amount of lubricant that accumulates at the seal runner during operation in the field.

Abstract: A multi-plate clutch is provided to couple a drive shaft from a gas turbine engine with a driven shaft of a lift fan. When disengaged the plates of the clutch can be physically separated. Plates of one shaft are coupled to the shaft with individual energy members that return the plates to a disengaged position. The plates of the other shaft can be coupled together with a travel member and/or lug key and energy devices between at least some of the plates.

Abstract: A gas turbine engine is provided that includes a gearbox operable to selectively couple a relatively high pressure spool shaft to a relatively low pressure spool shaft. In one form the gearbox includes a cone clutch that engages a male member of the cone clutch to a female member of the cone clutch during an engine start of the gas turbine engine. A relatively high pressure of a working fluid can be used to bring the male member and the female member together. A spring can also be used to urge the male member and the female member apart when the working fluid is at a relatively low pressure.

Abstract: A method for evaluating a lubrication containment system is disclosed herein. In one lubrication containment system applicable to the inventive method, a seal runner can be fixed to the rotatable structure and seal against a static radial seal supported by the sump housing. The method of the invention includes the step of rotating the structure relative to the sump housing. The inventive method also includes the step of directing test fluid to the structure inside the sump housing. The inventive method also includes the step of quantifying an accumulation of test lubricant at the seal runner during rotation by omitting the radial seal from the lubrication containment system. As a result, test lubricant can pass out of the sump housing. The amount of test lubricant that passes out of the sump housing, past the location where the seal runner would be or would have been, corresponds to the amount of lubricant that accumulates at the seal runner during operation in the field.