Product Manual

continuously based on its ability to dissipate the heat caused by
operating friction.
In practice, the mass of a cast iron reducer housing and its oil lubrica-
tion system provide sufficient heat dissipation so that mechanical and
thermal ratings are essentially equal. Aluminum housed or grease-
lubricated reducers have less heat dissipation mass and therefore
require consideration of thermal rating.
Service Factor: Established by the American Gear Manufacturers
Association (AGMA), gearing service factors are a means to adjust a
reducer’s ratings relative to an application’s load characteristics. Proper
determination of an application’s service factor is critical to maximum
reducer life and trouble-free service. Unless otherwise designated,
assume a manufacturer’s ratings are based on an AGMA-defined service
factor of 1.0, meaning continuous operation for 10 hours per day or
less with no recurring shock loads. If conditions differ from this, input
horsepower and torque ratings must be multiplied by the service factor
selected from one of the tables below. In addition, AGMA has
standardized service factor data for a wide variety of specific
applications. Contact your manufacturer for this information.
Input Speed: Gear reducers are best driven at input speeds common
in industrial electric motors, typically 1200, 1800 or 2500 RPM. This
provides sufficient “splash” for the reducer’s lubrication system, but not
so much as to cause oil “churning.” For input speeds under 900 RPM or
above 3000 RPM, consult the manufacturer. Alternative lubricants may
be suggested.
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Graphic shows compact size
of an aluminum-housed worm
gear reducer compared with
a cast iron housed reducer
of the same center distance.
Smaller size and lighter
weight can be an application
advantage in many cases, but
reduced mass means that the
reducer’s thermal rating must
be carefully considered.