A backdrive braking element is provided for preventing backdrive of a shaft. It includes a poly-lobed locking mechanism including an unlock shaft that has a polygon shaped inside profile and is coupled to a poly lock drive and brake assembly. The poly lock drive and brake assembly includes a plurality of poly lock drive and brake segments and is contained within the interior cavity of a housing.

A lift system comprises a drum that rotates about an axis, an elongate member that winds around the drum when the drum rotates in a first direction and that unwinds from the drum when the drum rotates in a second direction, a drive mechanism operable to rotate the drum, and a braking mechanism adapted to inhibit rotation of the drum. The braking mechanism includes a brake disk rotatable with the drum, a movable brake pad, and a ramp that guides movement of the movable brake pad. A method of operating the lift system comprises rotating the drum in a first direction to wind the elongate member onto the drum, rotating the drum in a second direction to unwind the elongate member from the drum, and moving the brake shoe along the ramp to thereby cause the movable brake pad to be compressed against the brake disk.

Embodiments herein relate to a permanent magnet (PM) motor driven hoist with a motor based electromagnetic brake. The hoist includes a direct current (DC) power source, a PM motor having stator coils and a PM rotor operably coupled to a cable drum with a cable wrapped thereon. The hoist also includes a controller operably connected to the direct current power source and the PM motor, wherein the controller is configured to control the PM motor employing a method to brake the PM motor. The method includes generating control signals in the controller based on a position of the PM motor, applying a braking command signal to the PM motor to magnetically lock the PM rotor of the PM motor for a selected duration, removing the braking command signals for a second selected duration, and repeating the generating, applying, and removing until the PM motor has stopped.

A propulsion unit includes a platform, a propulsion assembly, and a tether. The propulsion assembly facilitates selective launching of a tire deflation device from the platform. The tether is coupled to the platform and is configured for attachment to a deflation device.

A lift system comprises a drum that rotates about an axis, an elongate member that winds around the drum when the drum rotates in a first direction and that unwinds from the drum when the drum rotates in a second direction, a drive mechanism operable to rotate the drum, and a braking mechanism adapted to inhibit rotation of the drum. The braking mechanism includes a brake disk rotatable with the drum, a movable brake pad, and a ramp that guides movement of the movable brake pad. A method of operating the lift system comprises rotating the drum in a first direction to wind the elongate member onto the drum, rotating the drum in a second direction to unwind the elongate member from the drum, and moving the brake shoe along the ramp to thereby cause the movable brake pad to be compressed against the brake disk.

A propulsion unit includes a platform, a propulsion assembly, and a tether. The propulsion assembly facilitates selective launching of a tire deflation device from the platform. The tether is coupled to the platform and is configured for attachment to a deflation device.

A chain tensioning arrangement for a column pipe which is configured to house a submersible pump. The chain tensioning arrangement includes a radially extending cross beam, a spring arrangement connected to the cross beam, at least one spring member, and an arm that is movably connected to the cross beam. The arm includes an engagement member configured to optionally engage a chain connected to the pump. The arm is displaceable in the axial direction between a lower position and an upper position. The spring member is arranged to displace the arm in the direction from the lower position towards the upper position. Also described is a pump station including a column pipe, a submersible pump arranged in the column pipe and an axially extending chain connected to the pump and configured to move the pump in the column pipe.

A lift system comprises a drum that rotates about an axis, an elongate member that winds around the drum when the drum rotates in a first direction and that unwinds from the drum when the drum rotates in a second direction, a drive mechanism operable to rotate the drum, and a braking mechanism adapted to inhibit rotation of the drum. The braking mechanism includes a brake disk rotatable with the drum, a movable brake pad, and a ramp that guides movement of the movable brake pad. A method of operating the lift system comprises rotating the drum in a first direction to wind the elongate member onto the drum, rotating the drum in a second direction to unwind the elongate member from the drum, and moving the brake shoe along the ramp to thereby cause the movable brake pad to be compressed against the brake disk.

An electric winch device includes a required braking force estimation section which estimates a required braking force required to stop a free-falling object at a position at an allowable stopping height; a braking force determination section which determines, out of an operational braking force, each of a first braking force to be borne by a braking device and a second braking force to be borne by a braking force which is generated in an electric motor due to consumption of regenerative power; and a control section which causes the braking device to apply the first braking force to a winch drum. The braking force determination section determines the first braking force to be a braking force equal to or greater than the required braking force when, at a time of stopping of the free-falling object, the operational braking force is equal to or greater than the required braking force.

A brake or a clutch includes a central shaft, an output-side threaded driver, an output brake plate, an input brake plate, and an input-side threaded driver. The output-side threaded driver and the input-side threaded driver are rotationally locked to the central shaft, such as by splines. The output-side threaded driver is threaded to the output brake plate and the input-side threaded driver is threaded to the input brake plate. The output brake plate is threaded to the input brake plate in a direction opposite the threaded engagement of the drivers to the brake plates. The brake or clutch may include two stator plates and three friction discs located between the output brake plate and the input brake plate.