Air turbine starter having a panel and ratchet clutch
This patent describes a method of operating an air turbine starter in conjunction with a combustion turbine engine. It comprises: providing a pawl and ratchet clutch between the air turbine starter and a rotatable shaft of the combustion turbine engine, and thereby drivingly connecting the former to the latter for starting of the engine; connecting a ratchet wheel of the pawl and ratchet clutch to the air turbine starter for rotation in unison therewith; connecting a pawl hub portion of the pawl and ratchet clutch to the shaft of the combustion turbine engine for rotation in unison therewith; configuring the pawl and ratchet clutch to include centrifugally responsive pawl members carried by the pawl hub portion and drivingly connecting the latter to the ratchet wheel, and moving out of engagement with the ratchet wheel in response to rotation of the engine shaft; providing yieldable means biasing the pawl members into engagement with the ratchet wheel in opposition to centrifugal force to establish a pawl drop in speed of the shaft at which speed the pawl members move into engagement with the ratchet wheel during deceleration of the engine shaft; providing an engagement blocking member in a first position preventing engagement of the pawl members with the ratchet wheel; providing means moving the engagement blocking member to a second position only for a selected interval immediately following initiation of air turbine starter operation, in the second position the pawls being engagable with the ratchet wheel; and scheduling the no-load acceleration rate of the air turbine starter from rest so that the pawl drop in speed is not attained by the ratchet wheel during the selected interval.
- Assignee:
- Allied-Signal Inc., Phoenix, AZ
- Patent Number(s):
- US 4899534; A
- Application Number:
- PPN: US 7-165664A
- OSTI ID:
- 7011374
- Resource Relation:
- Patent File Date: 8 Mar 1988
- Country of Publication:
- United States
- Language:
- English
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