A planetary gear system for a turbomachine includes a forward planetary gear assembly including a plurality of forward planet gears meshed to a forward sun gear disposed on a power shaft and a forward ring gear meshed to the forward planet gears and an aft planetary gear assembly aft of the forward planetary assembly including a plurality of aft planet gears meshed to an aft sun gear disposed on the power shaft and an aft ring gear meshed to the aft planet gears. The system also includes a gear housing disposed between the forward planetary gear assembly and the aft planetary gear assembly. The gear housing includes a stationary carrier, wherein the forward and aft planet gears are rotatably mounted to the stationary carrier, and a mount extending radially from the stationary carrier that is connectable to a stationary portion of the turbomachine.

A planetary gear system for a turbomachine includes a forward planetary gear assembly including a plurality of forward planet gears meshed to a forward sun gear disposed on a power shaft and a forward ring gear meshed to the forward planet gears and an aft planetary gear assembly aft of the forward planetary assembly including a plurality of aft planet gears meshed to an aft sun gear disposed on the power shaft and an aft ring gear meshed to the aft planet gears. The system also includes a gear housing disposed between the forward planetary gear assembly and the aft planetary gear assembly. The gear housing includes a stationary carrier, wherein the forward and aft planet gears are rotatably mounted to the stationary carrier, and a mount extending radially from the stationary carrier that is connectable to a stationary portion of the turbomachine.

A gas turbine engine including a drive shaft that drives a propulsor. A frame which supports the drive shaft is a K-frame bearing support. A gear system is connected to the drive shaft. The gear system includes a gear mesh that defines a gear mesh lateral stiffness and a gear mesh transverse. A flexible support supports the gear system that defines a flexible support transverse stiffness and a flexible support lateral stiffness. The flexible support lateral stiffness is less than 8% of the gear mesh lateral stiffness.

A gas turbine engine including a drive shaft that drives a propulsor. A frame which supports the drive shaft is a K-frame bearing support. A gear system is connected to the drive shaft. The gear system includes a gear mesh that defines a gear mesh lateral stiffness and a gear mesh transverse. A flexible support supports the gear system that defines a flexible support transverse stiffness and a flexible support lateral stiffness. The flexible support lateral stiffness is less than 8% of the gear mesh lateral stiffness.

A hydrostatic drive system is disclosed which allows for simpler and more robust control of hydraulic vibration. The system comprises first and second hydraulic drive units and a variable damping device. At least the first hydraulic drive unit is a variable displacement type and comprises a displacement control. The variable damping device comprises at least one variable element. The system comprises a first linkage apparatus between the displacement control and the variable element and is operable to control the variable element in accordance with the displacement of the displacement control.

A hydrostatic drive system is disclosed which allows for simpler and more robust control of hydraulic vibration. The system comprises first and second hydraulic drive units and a variable damping device. At least the first hydraulic drive unit is a variable displacement type and comprises a displacement control. The variable damping device comprises at least one variable element. The system comprises a first linkage apparatus between the displacement control and the variable element and is operable to control the variable element in accordance with the displacement of the displacement control.

A mounting link between an engine and a gearbox comprises an engine attachment piece, a gearbox attachment piece, and primary and secondary retention fasteners. The engine attachment piece is rotatably secured to the engine, and the gearbox attachment piece is rotatably secured to the gearbox. The primary retention fastener rigidly constrains the gearbox attachment piece with respect to the engine attachment piece in a single degree of freedom, but is configured to shear at a breakpoint load. The secondary retention fastener constrains the gearbox attachment piece loosely with respect to the engine attachment piece, and can withstand the breakpoint load. The gearbox attachment piece and engine attachment piece abut in a friction fit that provides Coulomb damping.

A mounting link between an engine and a gearbox comprises an engine attachment piece, a gearbox attachment piece, and primary and secondary retention fasteners. The engine attachment piece is rotatably secured to the engine, and the gearbox attachment piece is rotatably secured to the gearbox. The primary retention fastener rigidly constrains the gearbox attachment piece with respect to the engine attachment piece in a single degree of freedom, but is configured to shear at a breakpoint load. The secondary retention fastener constrains the gearbox attachment piece loosely with respect to the engine attachment piece, and can withstand the breakpoint load. The gearbox attachment piece and engine attachment piece abut in a friction fit that provides Coulomb damping.

A steering assembly includes a rack assembly coupled to a road wheel. The rack assembly includes a housing, a ball screw, a bearing, and a retainer. The housing defines an injection port. The ball screw is at least partially received within the housing. The bearing is received within the housing and rotatably supports the ball screw. The retainer is received within the housing and includes a first retainer portion and a second retainer portion. The first retainer portion cooperates with the housing. The second retainer portion extends from the first retainer portion and is spaced apart from the housing. The second retainer portion defines a channel. The channel, the second retainer portion, and a surface of the housing defines an injection pocket.

A steering assembly includes a rack assembly coupled to a road wheel. The rack assembly includes a housing, a ball screw, a bearing, and a retainer. The housing defines an injection port. The ball screw is at least partially received within the housing. The bearing is received within the housing and rotatably supports the ball screw. The retainer is received within the housing and includes a first retainer portion and a second retainer portion. The first retainer portion cooperates with the housing. The second retainer portion extends from the first retainer portion and is spaced apart from the housing. The second retainer portion defines a channel. The channel, the second retainer portion, and a surface of the housing defines an injection pocket.