Mcdonnell Douglas Helicopter Company

Yih-Jen D Chen

Gregory F Heath

Vijay J Sheth

Faydor L Litvin

Ronald E Gilbert

Murugappan Meyyappa

Ningxin Chen

Michael T Morris

A precision grinding apparatus includes a grinding worm for precision grinding a case-hardened face gear. A shaper is first placed into contact with a face gear, to thereby shape a surface of the face gear into a plurality of face gear teeth. The shaper is then removed, and the face gear is case hardened. The grinding worm is disposed in a normal orientation to the case-hardened face gear and includes a spiral tooth extending along a perimeter of the grinding worm. The spiral tooth of the grinding worm is adapted to contact and precision grind the case-hardened gear. A dressing tool includes a protrusion for contacting the spiral tooth of the grinding worm, as the spiral tooth contacts and precision grinds the case-hardened face gear. The dressing tool thus maintains the shape of the grinding worm to within a desired tolerance range.

Apparatus and method for precision grinding face gear

A shaft deflection controller includes an input driveshaft adapted for inputting power from an engine. The input driveshaft includes an axis of rotation and a spur pinion at an end of the input driveshaft. The axis of rotation of the input driveshaft changes, relative to a frame, with deflections of the input driveshaft. Two face gears are adapted for meshing with the spur pinion of the input driveshaft. A flexible shaft stabilizing mount includes an inner sleeve portion and a mounting flange. The inner sleeve portion includes a base portion connecting the inner sleeve portion to the mounting flange and a plurality of cage spring members. The mounting flange is connected to and concentric with the inner sleeve portion. The flexible shaft stabilizing mount controls the deflection of the input driveshaft by applying forces onto the input driveshaft, which tend to resist changes in the alignment of the axis of rotation of the input driveshaft. The flexible shaft stabilizing mount is connected to a rigid frame. An inner surface portion of a stiffening ring contains a curvature and surrounds and contacts the inner sleeve portion of the flexible shaft stabilizing mount.

Shaft deflection controller

A concentric face gear assembly includes a first face gear having first face gear teeth and second face gear having second face gear teeth. At least one input pinion contacts both the first face gear teeth and the second face gear teeth, and at least one idler pinion contacts both the first face gear teeth and the second face gear teeth. The first face gear is adapted for directly driving a rotor, but the second face gear is not adapted for directly driving a rotor. The load carried by the first face gear includes the force needed to drive the rotor. Since it does not drive a rotor, the second face gear does not comprise a web or spline attachment and is therefore lightweight. Both the first face gear and the second face gear include thrust bearings, which are located radially outwardly of the first face gear teeth and radially inwardly of the second face gear teeth. The first face gear includes a web, which is relatively thin due to the thrust bearing of the first face gear being located radially outwardly of the first face gear teeth rather than radially inwardly of the first face gear teeth.

Concentric face gear transmission assembly

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Chandler, AZ, United States of America

Yih-Jen D Chen