It isn't just the motor(electric or hydraulic) that powers a winch, you have a series of gears to multiply the power provided by the motor to be strong enough to be able to pull the weight. In electric winches, the gear ratio is usually around 300:1, even with a strong motor, whereas incase of hydraulic winches its around 5:1. In PTO winches, the ratio is usually about 20:1.
There are usually 3 types of gears used in winches, no matter what the power source is(PTO,hydraulic or electric).
P.T.O. winches usually all use worm gears. There are a few electric and hydraulic winches too that use worm gears.
Then there are spur gears, but very few winches use them. Only competition winches, which besides the power, must also rely on the actual winching speed generally use spur gears. The Warn M8274-50 is probably the only reliable spur geared winch out there.
Then there are planetary gears. This type is the most common type of gear, and the advantage being that its small size and compact arrangement wherein it fits in the inside of the winch cable drum makes its the ideal gearing option. 90% of the winches out there, hydraulic or electric, warn,ramsey,britpart,or even the inferior Runva chinese winches, use a planetary gearbox.
Then there are winches that use a mixture of all 3 types of gears. I have this Russian winch at home. It has there 2 24volt motors on top of the winch, and both independently power a set of spur-gears, out of which 1 motor drives a small diameter lesser tooth and higher gear ratio'ed spur-gear, while the other drives a bigger wheel with lots of teeth and a lower gear ratio, and then the gears of both the motors mesh together. The arrangement is such, that one motor through it's gears controls speed, and the other motor controls power, with the final product speed wise being the sum of average speed of both the motors, like for i.e. if both motors are moving at 6000rpm, then the final output speed too is 6000rpm. But if 1 is moving at 6000rpm and the other is not moving(0rpm), then the final output speed is 3000rpm. Also b'cos of the peculier arrangement of the spur gears, the winch provides both speed and power simultaniously.
After the spur gears, the power line of delivery moves to the planetary gears inside of the spool drum, with the other end of the drum having another set of gears, the worm gears. The reason for that is that there is another gearbox there, which can be used activate the winch by hand, to override the winch incase of an emergency or power or motor failure, which is powered by the worm gear on the other end of the drum.
This ship winch seems like it uses a gearbox of worm gears, and the drum by itself cannot be powered alone by a motor and without a gearbox. Infact, i know a person who made a winch all by himself, by using the drum roll and cable out of a Nissan 1-tonner winch. He even used the stock winch gearbox, but to it he added another 50:1 ratio worm gear, the gearbox of which is used to make those shop shutters that are rolled down by hand rather than being pulled down. The design was based the same russian winch and the end product was a pretty impressive winch which too hand an electric cum hand powered operation. |