The Ins And Outs Of A Powerful Recovery Tool
Winches are one of the most drooled-over accessories on the list of desired 4x4 components. They provide a sense of security and elevate you to the next level in the unofficial off-road caste system. But how do these motors and spools of rope do what they do? And how do you know which one you should be saving your Franklins for?
For this article, we focused on two winches that show common and popular technology in the industry. In addition to the Smittybilt and Warn products shown here, other key players in the industry include Mile Marker and Ramsey. We’re also going to examine winch technology. However, properly using a winch and the accessories that are available to work with them are just as important.
A winch is a pretty simple-looking piece of machinery. But there are a lot of parts that make it work, and understanding what each part does is very important to help you to choose the right one for your 4x4.
Nearly all winches have these seven key components:
Motor: Creates turning motion.
Transmission: Multiplies the torque of the motor to generate speed and pulling power.
Rope: Spools in and out and is made of either steel or synthetic; often referred to as cable.
Drum: What the rope is wrapped around.
Clutch: Allows you to switch between free-spooling to pull the line out, and engaged, which lets the motor spool the rope in and out.
Brake: Slows the drum when the motor is turned off and holds its position when the clutch is engaged.
Electronic controls: Switches the direction of the motor, controls activation, and manages the high amperage that an electric winch motor requires.
At this point, it’s appropriate to mention that there are also hydraulic winches and even some that use other power sources. For this article, though, we’ll focus on how an electric winch functions.
For winches, electric motors are rated in horsepower. If everything else about two winches were the same, more horsepower would mean more pulling power and more speed. However, you can almost never compare winches by horsepower alone because everything else will be different too. There is no third-party testing or industry standard by which winch manufactures rate electric winch motors (or line speed, for that matter).
Similar to the transmission in your 4x4, a winch transmission uses gearing to change the output speed relative to how fast the motor is spinning. Gear ratios range from about 150:1 to 300:1, giving the winch its pulling power. Just as with your axle gears, higher numeric ratios provide more power, but at the expense of speed. A good winch design matches the electric motor power and gear ratio to provide a desirable compromise between speed and pulling power.
There are two types of gearing typically found in winches. The less common type for off-road recovery is a worm-style. This is a pretty simple design, very similar to a mechanical speedometer drive in the tailshaft of a transfer case. A gear on a shaft meshes with gears cut into the outside of a ring gear. The advantage is simplicity in design. This is a very strong design and offers self-braking. They typically have lower line speed, and the shaft-mounted gear makes winch-mounting a bit of a challenge. This is also a less efficient design, meaning it takes more electric-motor power to provide the same line pull.
The more common type is the planetary variant. These use a planetary gearset, similar to what you will find in an automatic transmission. Planetary gears rotate around a sun gear, and the ring gear is pressed inside of a case and has the teeth facing inward. This is a much more efficient design than the worm-style; it fits better on the winch for easier mounting; and it engages easily. Planetary gearsets offer virtually zero self-braking and require a brake to slow and stop the drum when the motor is turned off.
A third style of gearing is the spur gear, which is the most efficient. These use a small and large gear with straight-cut teeth that mesh directly. They offer very fast line speed and the highest efficiency of the three types of transmissions. They also have very little self-braking. Packaging is a bit of a challenge, as the gears make the height of the winch pretty tall. The Warn M8274 is the only common off-road winch that uses this type of gearing.
Changes in technology have made it possible to have planetary gearsets with very high speed and strength, and their advantage in fitting compactly on the winch have made them very popular in the 4x4 market. Worm-style gearsets are often seen on flatbed tow trucks.
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