Abstract: A brake actuator has a motor that provides input rotation in first and second directions. A reducer couples to the motor and reduces the input rotation into an output rotation to be applied to a brake screw of a progressive cavity pump drive. A sensor measures rotational speed of the drive shaft. In manual operation, an operator can view an indication of the rotational speed and can manually operate the motor accordingly to control rotation of the shaft. In automated operation, a controller automatically controls the motor based on the rotational speed measured by the sensor. The controller can also use a torque sensor to detect the torque applied to the brake screw, a displacement sensor to detect displacement of the brake screw, and/or a current sensor to detect the current consumption of the motor.

Abstract: An auxiliary braking device can be used for wellhead applications having a progressive cavity pump. A housing of the device independently mounts on the pump's existing drive using a mounting member, and an adapter on the housing connects to a rotatable drive shaft of the pump. A hydraulic motor on the housing has a motor shaft mechanically coupled to the adapter by a plurality of gears or the like. A control valve couples to the hydraulic motor and operates to control communication of hydraulic fluid through the hydraulic motor, thereby controlling rotation of the rotatable shaft. A controller and electric sensors can operated the control valve in response to the sensed rotation of the shaft. Alternatively, mechanical mechanisms can operate the control valve in response to the rotation of the drive shaft.