A manual chain hoist is suspended above the object to be lifted by hooking or mounting it on a rigid and sturdy structural frame. It has two chains: the hand chain that is pulled by hand and the load chain, made of high-strength material, (e.g., steel) that lifts the load. The hand chain is much longer than the load chain. First, a grab hook is attached to the object to be lifted. The worker, who is situated at a safe distance from the load, pulls the hand chain several times. As the worker pulls the hand chain, it turns the cog; this causes the driveshaft to rotate. The driveshaft transmits the force into a series of gears with a different number of teeth. The force is concentrated by transmitting the torque from the fast-moving, smaller gears to slow-moving, larger gears. This force rotates the sprocket, which pulls the load chain together with the object. The load chain is looped around the sprocket as it decreases its exposed length and vertically displaces the object.
Electric chain hoists use a load chain as the lifting medium. The load chain is pulled by a motor that converts electrical energy to mechanical energy used to lift the load. The electric hoist motor is housed inside a heat-dissipating shell, which is typically made from aluminum. The hoist motor is equipped with a cooling fan to dissipate heat quickly during its continuous service and to enable its operation in hot environments.
An electric chain hoist is suspended above the object to be lifted by hooking or mounting it on a rigid structural frame. A hook is attached to the end of the load chain that grabs the object. To commence the lifting operation, the worker switches on the hoist motor. The motor is incorporated with a brake; the brake is responsible for stopping the motor or holding its driven load by applying the necessary torque. The power supply is continuously released by the break during the vertical displacement of the load.
Electric wire rope hoists lift loads utilizing a wire rope as the lifting medium. Wire ropes consist of a core that runs through the center of the wire rope and several strands of wire intertwined around the core. This construction forms a higher-strength composite rope. Wire ropes intended for hoisting applications are typically made from carbon steel, stainless steel, Monel, and bronze; these materials have high resistance to wear, fatigue, abrasion, and corrosion.
Electric wire rope hoists, like electric chain hoists, are equipped with a hoist motor with an incorporated braking system. They also utilize a series of gears inside a gearbox that amplify the transmitted torque from the motor. The concentrated force from the gearbox is transmitted to a spline shaft. The spline shaft then rotates the winding drum. As the wire rope is pulled to vertically displace the load, it is wound around the winding drum. The rope guide moves around the winding drum to place the wire rope properly in the grooves, which run helically on the winding drum lateral. The rope guide prevents the wire rope from tangling. The wire rope also requires lubrication.
Post time: Jul-15-2022