Abstract: Bolt hole stress in rotor disks having bolted joints is reduced by passing relatively hot secondary flow path air (such as compressor discharge air) through each bolt hole to heat the disk from inside the bolt hole. In doing so, the temperature distribution in the area of the bolt hole is made more uniform and the stress is dramatically reduced. The bolted joint includes a bolt hole formed in a first rotor disk and a bolt disposed in the bolt hole such that a channel is defined between the bolt and the bolt hole. A first nut or abutment is attached to a first end of the bolt, and a second nut or abutment is attached to a second end of the bolt. A first passage associated with the first abutment provides fluid communication with the channel, and a second passage associated with the second abutment provides fluid communication with the channel, thereby allowing the relatively hot fluid to pass through the channel during engine operation.

Abstract: A brake-pressure modulation device in which a hydraulic unit, fitted with solenoid valves, with return pumps, accumulators and dampers of an anti-lock brake system also has a tandem brake master cylinder. The hydraulic unit has a housing with a standard location hole, into which four lip seals identical at least in their outside diameters are inserted. The lip seals hold a primary and a secondary piston of the tandem brake master cylinder. The use of four lip seals with the same outside diameter makes it possible to use the same housing with the standard location hole for different types of vehicle, even when the piston diameter and the operating stroke are changed.