Abstract: A coolant system is arranged to be driven by a prime mover of an aircraft. The coolant system comprises a fluid circuit with a fluid therein, the fluid for cooling an electricity generator located in the fluid circuit. The fluid circuit comprises: a cooling path passing via at least one cooled component of the generator; a first fluid flow source configured to deliver a first fluid flow to the cooling path; a second fluid flow source configured to generate a second fluid flow; and a valve arrangement configured to selectively direct at least a proportion of the second fluid flow away from the cooling path in dependence on a measured operational parameter of the generator. An aircraft propulsion system and an aircraft can also include the coolant system.

Abstract: A high pressure pump including a pump body, a pump housing within which at least part of the pump body is located, a gallery defined between the pump body and the pump housing, the pump body having a pump outlet which communicates with the gallery, and the pump housing having an outlet port which communicates with the gallery, and a filler located within the gallery, the filler being located at least in the part of the gallery most remote from the pump outlet.

Abstract: A rotary electric machine comprises a rotor rotatable within a stator assembly, the stator assembly comprising a stator body defining a plurality of stator slots accommodating electrical conductors, a slot liner being provided within each slot to provide electrical insulation between the stator body and the electrical conductors, wherein each slot liner protrudes from an end of the stator slot and carries an armor element to protect the slot liner and associated conductors from erosion while permitting efficient cooling.

Abstract: A rotary electric machine comprises a rotor rotatable within a stator assembly, the stator assembly comprising a stator body defining a plurality of stator slots accommodating electrical conductors, a slot liner being provided within each slot to provide electrical insulation between the stator body and the electrical conductors, wherein each slot liner protrudes from an end of the stator slot and carries an armour element to protect the slot liner and associated conductors from erosion whilst permitting efficient cooling.

Abstract: A system for determining the speed of a pump (6) used to supply hydraulic fluid for a control system is disclosed. The pump output exhibits small pressure fluctuations and these are detected by a transducer (50) and provided to a data processor (54) which analyses the output of the transducer and calculates the speed of the pump.

Abstract: A clamp pressure controller for a variable ratio belt drive system for a generator is provided. The controller monitors the voltage at the output of the generator. If this falls the controller increases the clamp pressure so as to prepare the drive system for the additional torque/force it will be required to transmit. The increase in clamp pressure is rapid so as to prevent belt slip from occurring.

Abstract: A clamp pressure controller for a variable ratio belt drive system for a generator is provided. The controller monitors the voltage at the output of the generator. If this falls the controller increases the clamp pressure so as to prepare the drive system for the additional torque/force it will be required to transmit. The increase in clamp pressure is rapid so as to prevent belt slip from occurring.

Abstract: A belt clamp force regulator is provided for controlling the clamp force exerted on a drive belt in a continuously variable transmission. The regulator seeks to maintain a clamp force greater than that required to transmit the mechanical load consistent with the output of the generator. This ensures that the belt will not slip. However, the controller reduces belt clamp when it can so as to improve the service life of the belt.

Abstract: A deaerator is provided in which the oil to be deaerated is supplied to first and second chambers and, respectively, arranged in a side by side manner. The oil is introduced tangentially so that a rotary motion is introduced therein. The rotary motion causes the oil and air entrained therein to separate out due to centrifugal/centripetal forces. Air is removed via a centrally disposed tube.