Abstract: A linear actuator system having an actuator housing, a motor assembly, a screw shaft, a thrust tube, and a nut assembly. The nut assembly is engaged with the screw shaft and directly coupled with the thrust tube. The nut assembly can define a mechanical fitting for direct physical engagement between the thrust tube and the nut assembly, absent additional load bearing components intervening therebetween. The nut assembly is configured to convert rotational motion of the rotor about the longitudinal axis to linear motion of the thrust tube along the longitudinal axis. A cooling loop can be at least partially embedded, potted or seated within the actuator housing, with a thermally conductive material disposed at least partially about the cooling loop to conduct heat from the actuator housing.

Abstract: A linear actuator system having an actuator housing, a motor assembly, a screw shaft, a thrust tube, and a nut assembly. The nut assembly is engaged with the screw shaft and directly coupled with the thrust tube. The nut assembly can define a mechanical fitting for direct physical engagement between the thrust tube and the nut assembly, absent additional load bearing components intervening therebetween. The nut assembly is configured to convert rotational motion of the rotor about the longitudinal axis to linear motion of the thrust tube along the longitudinal axis. A cooling loop can be at least partially embedded, potted or seated within the actuator housing, with a thermally conductive material disposed at least partially about the cooling loop to conduct heat from the actuator housing.

Abstract: A compact, axially aligned brushless servo motor actuation unit configured to manipulate a choke valve to control the pressure within a borehole during managed pressure drilling. The actuation unit including a brushless servo, a gear reduction assembly and a planetary roller actuator substantially aligned along a longitudinal axis and housed within a tubular housing, the gear reduction assembly defining a hollow core sized to enable a portion of a roller screw of the planetary roller actuator to pass therethrough for the purpose of reducing the overall length of the actuation unit along the longitudinal axis.

Abstract: A compact, axially aligned brushless servo motor actuation unit configured to manipulate a choke valve to control the pressure within a borehole during managed pressure drilling. The actuation unit including a brushless servo, a gear reduction assembly and a planetary roller actuator substantially aligned along a longitudinal axis and housed within a tubular housing, the gear reduction assembly defining a hollow core sized to enable a portion of a roller screw of the planetary roller actuator to pass therethrough for the purpose of reducing the overall length of the actuation unit along the longitudinal axis.