Electric actuator with a fail-safe mode of operation
AssigneeMetso Automation USA Inc.
InventorLeonard T. ARMSTRONG
Life of this patent
Estimating the term…
Abstract
Aspects of the disclosure provide an electric actuator including a first driving source coupled to an output through a first pathway created by a transmission, a second driving source coupled to the output though a second pathway created by the transmission that, upon the electric actuator losses electrical power to the electric actuator, causes the output to be positioned at a fail-safe position, a differential coupled to the first driving source and the second driving source through a third pathway created by the transmission to store energy from the first driving source in the second driving source, and a switching controller that is configured to control switching the transmission between the first pathway, the second pathway, and the third pathway.
Claims20
An electric actuator, comprising:
- a first driving source coupled to an output through a first pathway created by a transmission;
- a second driving source coupled to the output though a second pathway created by the transmission that, upon the electric actuator losses electrical power to the electric actuator, causes the output to be positioned at a fail-safe position;
- a differential coupled to the first driving source and the second driving source through a third pathway created by the transmission to store energy from the first driving source in the second driving source;
- and
- a switching controller that is configured to control switching the transmission between the first pathway, the second pathway, and the third pathway.
A method for driving an electric actuator, the method comprising:
- supplying electric power to a first driving source coupled to a differential driving a transmission coupled to an output or a second driving source;
- disengaging a first brake and engaging a second brake of the electric actuator to establish a first pathway that causes the first driving source to drive the differential causing the transmission to drive the output;
- disengaging the first brake and the second brake of the electric actuator, upon loss of electric power to the electric actuator, to establish a second pathway that causes the second driving source to drive the differential causing the transmission to drive the output;
- and
- engaging the first brake and dis-engaged the second brake to establish a third pathway that causes the first driving source to drive the differential causing the transmission to drive the second driving source.
A transmission of an electric actuator comprising:
- a differential including a carrier, three or more bevel gears arranged inside the carrier, and a carrier gear fixed to the carrier;
- a motor gear train driving a first bevel gear of the differential;
- a spring gear train coupled to the carrier gear of the differential;
- and
- an output gear train coupled to a second bevel gear of the differential.
Dependencies are inferred from the claim text.