This high speed helical gear unit standard is provided as a basis for improved communication regarding:

- establishment of uniform criteria for rating;

- guidance for design considerations; and,

- identification of the unique features of high speed gear units.

Application

Operational characteristics such as lubrication, maintenance, vibration limits and testing are discussed. This standard is applicable to enclosed high speed, external toothed, single and double helical gear units of the parallel axis type. Units in this classification are:

- single stage units with pitch line velocities equal to or greater than 35 meters per second or rotational speeds greater than 4500 rpm;

- multi-stage units with at least one stage having a pitch line velocity equal to or greater than 35 meters per second and other stages having pitch line velocities equal to or greater than 8 meters per second.

Limits specified are generally accepted design limits. When specific experience exists for gear units of similar requirements above or below these limits, this experience may be applied.

Marine propulsion, aircraft, automotive, and epicyclic gearing are not covered by this standard.