Speed reducer

The required service factor is an important specification. The service factor is defined as the ratio of calculated basic horsepower to the applied horsepower. The service factor can be as high as 2 for spiral-bevel reducers, but with continuous service this factor could be as low as 1.25 to have a good reducer life. 

Lubrication is highly important to assure long trouble-free service life. The lubrication system should be capable of providing lubrication for short periods of time and for reverse rotation operation. 

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Fig. 9. Cutaway view of a briquettiag—compactiag machine. A, predensifying feeder B, feeder screw C, machine housing D, antifriction bearing E, machined bearing block F, base frame G, pocketed or cormgated roUs H, hydrauHc system I, speed reducer J, gears K, hydrauHc accumulator and L,...

The power P is only that imparted to the liquid by tbe impeller. It is not tbat delivered to tbe motor drive, which additionally includes losses in the motor and speed-reducing gear. These may total 30 to 40 percent of P A stuffing box where tbe shaft enters a covered vessel causes additional losses. 

The number of speed reduetions is another way to classify conveyor drives. Most common of the speed-reduction methods is the two-step system, in which the motor is coupled to a speed reducer and the slow-speed shaft of the reducer is connected to the conveyor-drive shaft by a V belt or a roller chain. The second reduction not only permits the use of a simpler speed reducer but also allows a more flexible layout of the motor and reducer mounting plate. On many installations this eliminates the need for a specially designed drive mount. 

Since it is good practice to maintain a selected inventory of spare parts for drives, economy can be achieved by standardizing conveyor drives throughout the plant. For example, intermediate speed reduction by means of V belts, sheaves or chains, and sprockets can frequently permit using the same speed-reducer size for several drives. Thus, it may be necessary to keep only one repair-stock speed reducer for a number of conveyors. 

At rated speed up to 80-90%. At lower speeds reduces more than the a.c. drives because of... 

If a system disturbance requires extra generating capacity, the generator may drop speed, reducing the frequency proportionately. The under-frequency relay 81-G will detect such a condition and operate a systematic load shedding in a programmed manner in order to meet the load demand. If the abnormal condition persists, the generator is taken off the main supply system. 

This standard API Standard 613 covers special purpose gears. They are defined as gears, which have either or both actual pinion speeds of more than 2900 rpm and pitchline velocities of more than 5000ft/min (27 meters/sec). The standard applies to helical gears employed in speed-reducer or speed-increaser units. 

Speed Reducer Number Type Model Manufacturer Reduction Ratio AGMA Mechanical H.P. Rating Sen/ice Factor at Rated H.P. of Driver No. of Reductions ... 

For the slower speed compressors, an evaluation must be made concerning the use of direct-connected motors that are more expensive, or the use of a less expensive 1,800 rpm or a 1,200 rpm motor with a speed-reducing gear. As before, the evaluation must include all factors, such as installation and the extra space, as well as some factor for additional maintenance. 

Spherical roller bearings support of radial and thrust load, expecially when the shaft is long excellent paper mill machinery, air compressors, speed reducers, cranes... 

System efficiency is influenced by the air plenum chamber and fan housing. Industrial axial flow fans in proper system design will have efficiencies of approximately 75% based on total pressure. Poor designs can run 40%. Speed reducers are about 75% mechanically efficient. 

External gear None Power input and heat generated increases with increasing viscosity May be suitable for handling viscosities up to 25 000 centristokes without modification. For high viscosities (a) Clearances may be increased (b) Speed reduced (c) Number of gear teeth reduced... 

Figure 5.123 a and b. Gas-liquid mixing modes a) bubble column behaviour (high gas flow, low rotor speed) b) circulating tank behaviour (high rotor speed, reduced gas flow). 

The amine solution (4) is now immediately run in dropwise over a period of 30 s and the stirrer speed reduced to 2000 rpm After 2-3 min the high-speed stirrer is replaced by a normal paddle stirrer and the dispersion stirred (500 rpm) for a further 30 min at room temperature to complete the interfacial polycondensation between terephthaloyl dichloride and diethylenetriamine. 

One offers oils and other greases to be applied in different process areas in the sugar mill industry. There are around 20 different products, and they are applied in different points like pumps, sugar cane conveyors, bearing turbogenerators, speed reducers and others. The aim is to identify opportunities to apply Chemical Leasing in other points of the process, and identify the payment index (for example per work hours). 

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