Linear compact electric actuator having a resilient kinematic chain

A method for controlling an electric actuator comprising a kinematic chain formed by at least the following elements:

• an electric motor driving a rotor carrying a worm gear, a threaded rod, a control member and a linking arm, the threaded rod being moved in a rotary motion by the worm gear according to a worm gear-type conversion, the conversion being irreversible, the threaded rod driving the control member in a linear motion according to a conversion from a rotary motion to a linear motion, the control member driving the linking arm, the linking arm driving at one end a valve member, the valve member moving towards an end-of-stroke position, abutting on a seat;
• making at least one of the elements of the kinematic chain of a plastics material which is resiliently deformable in compression or bending;
• causing a stroke of the kinematic chain to be greater than a stroke of the valve member so that the valve member applies a force on the seat in the end-of-stroke position, even in the absence of power to the electric motor;
• and
• controlling the actuator according to a succession of electrical pulses, wherein:
• (a) a first succession of the electrical pulses following a mid-level of electrical current brings the valve member from a position called “open” to a position called “closed” wherein the valve member is in abutment on the seat at the end of stroke,
• (b) a second succession of the electrical pulses following a high level, higher than the mid-level of the first succession of the electrical pulses, resiliently deforms the linking arm, the valve member applying a force to the abutment seat, and
• (c) a third succession of the electrical pulses following a low level, lower than the mid-level of the first succession of the electrical pulses, maintains the position of the valve member on the seat.