Single helical gear

If an intermediate gear is necessary, some manufacturers use single helical gears provided with thrust collars on the pinion shaft, as shown in Figures 4-32 and 4-33. The thrust collars not only neutralize the... 

Figure 4-32. Method of axial thrust transfer in a single helical gear with thrust collar.

Helical, double (also referred to as herringbone) Connects parallel shafts, overcomes high-end thrust present in single-helical gears, compact, quiet and smooth operation at higher speeds (1000 to 12,000 fpm or higher), high efficiencies ... 

Single-helical gears Gears have teeth of only one hand on each gear (Fig. 5.18). 

The gears are carburized, hardened, and ground. Normally single helical gears are used. They are calculated in accordance with MAAG design criteria, or to AGMA, ISO, or API standards, with a service factor of not less than 1.1. 

Figure 4-33. Working principle of thrust transmission shown on a single helical precision gear.

Top entering mixers are heavy duty equipment. They are usually fixed to a rigid structure or tank mounting. Either radial flow or axial flow turbines may be used. Speeds vary from 50 to 100 rpm and usually require a double set of helical gearing or a single set of worm gears to achieve these low speeds. Therefore, they are more expensive than single reduction mixers. 

Gearing is single helical or spur gear lubrication usually is an automatic spray type. Single drives are used up to 150 kW. Kilns requiring more than 150 kW may be equipped with dual drives, i.e., two driving... 

Single reduction/helical gearing for quiet operation... 

Spray-lubr icated, single-reduction helical gear (plain bearings). ... 

FIGURE 5.26 High-speed single-reduction helical gear drive. (Philadelphia Gear Corporation.)... 

This led to the knowledge that extreme high-speed gears, which must be equipped with toothed couplings for lateral critical speed reasons, should have a single helical toothing that is not affected by additional external thrusts. 

Gears, wherever used, can be a major source of problem and downtime. This standard specifies the minimum requirements for special-purpose, enclosed, precision, single- and double-helical one- and two-stage speed increasers and reducers of parallel-shaft design for refinery services. Primarily intended for gears that are in continuous service without installed spare equipment. These standards apply for gears used in the power industry. 

Drive type Direct gearing Single reduction helical... 

Other types of motors that may be encountered in mixer applications are gear motors, pony motors, and brake motors. Gear motors are composed of an electric motor with an attached gear reducer. Spur, helical, or worm gears can be used in single or multiple reductions to achieve a wide range of output speeds. Motor power, output speed, and output torque are all essential design variables. 

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