Merriam – Webster defines a winch as a machine for hauling or pulling. Specifically, a winch is a powerful machine with one or more drums on which to coil a rope, cable, or chain for hauling or hoisting. In industry, winches stand at the heart of machines as diverse as tow trucks, large industrial cranes, heavy hauling equipment and off road vehicles requiring self-recovery. The more elaborate designs have gear assemblies that can be powered by electric, hydraulic, pneumatic or internal combustions drives.
The two most common designs of winches used in the Industrial Marketplace are the Worm Gear Winch and the Planetary Winch. Worm gear winches, by design, provide a very rugged platform for heavy duty applications. The planetary winch design offers higher speed and higher efficiency when compared to its counterpart. However a separate breaking system is required with the planetary design. Which type of winch is better? It depends on the application. This is where a winch professional comes in; to help with the specification of the proper winch.
Most US manufactures design to the Industry Standard: SAE J706 Rating of Winches: SAE J706 is a voluntary standard for intermittent duty winches. Winches meeting this standard must comply with design guidelines for the free spool mechanism, brake holding force, drum diameter in relation to the cable diameter (8:1), cable anchor pocket and other design guidelines. As part of the testing procedure, all winches must be tested to a two times load test.
Worm Gear Winch
Worm gear winches have fewer moving parts than other designs and are known for their superior endurance and high reliability. The gear box of a Worm Gear Winch has two major parts, the worm and the main or bull gear. It is generally accepted in the industry that worm gear winches have a slower line speed and are less efficient than other designs. However, they are also generally self-braking, meaning that they stop when the driving worm gear stops and are extremely robust. Due to some new highly efficient gearing technology, there are some worm gear winches that have line speeds that are equal to their planetary counterparts for the same line pull. Reference: Ramsey Winch HSW 10,000 Worm Gear Winch has the same line speed as the HD-P 10,000.
The planetary winch has gained popularity because of its compact size, smooth operation and good resistance to torque loads. This design also allows for generally higher efficiency gear ratios than the standard Worm Gear Winch. The planetary winch gear box is made up of the sun gear surrounded by a number of planetary gears that engage the ring gear. The planetary winch is also more efficient than its worm gear counterpart. However this device does require a braking system to safely hold the load.
Other Major Components of the Winch: Although the basic industrial winch design is named after the winch gearbox, there are other components that make up the total winch product. The major ones of these are the Rope (Synthetic or Wire Rope); the Drum; the Clutch Assembly; the Braking System; and the Driving Motor (generally electric or hydraulic.)
Rope and Drum
The winch rope is stored on the drum in layers. The published rating of the winch is the “rated line pull on the first layer of rope on the drum.” The first layer is the layer closest to the drum.
Clutch Operation and Maintenance: There are several defining factors in the operation of a winch. One of the most important of these is the operation, inspection and care of the “Clutch Assembly.” The clutch is used to engage and disengage the gear and drum assemblies of the winch.
When the clutch is disengaged, the cable on the drum may be pulled off by hand, commonly known as “free spooling”. There are a number of specified ways to disengage the clutch assembly based on the type of winch, its design and the procedure for operation that is detailed in the winch owner’s manual.
To Disengage Clutch: Run the winch in the reverse direction until the load is off the cable. Pull outward on the clutch handle, rotate counterclockwise 90 degrees and release. With other designs, the clutch handle can be moved toward the drum until the clutch disengages. The Clutch is now locked out and the cable may be pulled off by hand. (Free Spool.)
To Re-engage the clutch, pull outward on the handle; rotate clockwise 90 degrees and release. In the other design shown, to reengage the clutch, the handle is pulled away from the drum to the, “IN” position. The drum is then rotated until the clutch jaws engage the drum jaws.
Important Note: The most important rule with respect to winch operation: The Clutch must be fully engaged before starting any winch operation. Failure to do so may result in the dropping of the load, with the potential for injury.
Clutch Inspection and Maintenance: As part of the normal maintenance procedure of the winch, the clutch assembly should be inspected regularly. These inspection procedures are detailed in the Winch Operation Manual provided by the winch manufacturer. As an example, on the Ramsey Winch HSW-10000 model, an inspection plug is provided on the top of the clutch housing. During the inspection procedure, this plug should be removed with the clutch engaged.
The jaw clutch must be fully engaged with the drum jaw to see if the Jaw clutch shows wear.
Drum jaws and clutch Jaw should have square edges. If the Drum jaws are rounded, the drum must be replaced. It is important to note that the drum should not be welded or machined in an attempt to eliminate round edges. If the drum jaws are rounded, the drum must be replaced. This is just one example of a clutch inspection procedure. The procedure can and will vary depending on the winch design. See the winch operation manual for the specific winch model and design.
The important thing to remember about the Winch Clutch Assembly:
- A fully engaged and properly maintained clutch will not release under load. The operator is responsible for ensuring the clutch is fully engaged before starting winching operations.
- A partial engagement of the clutch can result in a sudden loss of load and damage to the clutch mechanism, and the possibility of injury.
Summary: An industrial winch is a robust and reliable device that is used in a variety of industrial applications e.g., towing and recovery, heavy hauling etc. If properly maintained and operated correctly, it will provide service for a long time.