DRIVE BELT

Drimaren Z Drinking water Driography Drionic system Drip oil Dripolene Drive belts Drive shafts... 

Motor nd Drive. The preferred prime mover for a fan is usually an electric motor. Eor fans of low to moderate power, V-belt drives are frequently employed. This permits selection of fans that can be operated over a wide range of speeds rather than being limited to motor synchronous speeds. Furthermore, change of speed is less expensive with V-belt drives. However, fans requiring powerful motors, 37—75 kW (50—100 hp) and higher, are generally directly connected to the motor and driven at synchronous speed. 

Propeller Fa.ns, Propeller fans may have from 2 to 6 blades mounted on a central shaft and revolving within a narrow mounting ting, either driven by belt drive or directiy coimected. The form of the blade ia commercial units varies from a basic airfoil to simple flat or curved plates of many shapes. The wheel hub is small ia diameter compared to the wheel. The blades may even be mounted to a spider frame or tube without any hub. The housiag surrounding the blades can range from a simple plate or flat ring to a streamlined or curved beU—mouth orifice. 

A variable-speed drive is usually used on the feed and cross-belt drives to exercise control in separator operation, although the speed is not usually changed once the optimum operating condition is estabUshed. Feed rates and the selection of the number of magnetic poles are usually deterrnined by preliminary laboratory tests. The mineral types involved in the feed largely determine the number of poles selected. High intensity cross-belt separators are frequendy used in combination with induced-roU or electrostatic separators. 

V-belt drive assemblies are generally used with fans 3 m (10 ft) and less in diameter and motors of 22.4 kW (30 hp) and less. 

Roll presses are now manufactured by most cement-equipment manufacturers, for example Krupp-Polysius AG. For drives up to 1200 kW they are equipped with V-belt drives, allowing speed to be changed. Rolls in one particular crusher are 48 inches (1200 mm) in diameter and 30 inches (700-mm) wide and each weighs 90 tons. Machines with up to 2500 kW installed power and 1000 ton/h (900... 

Belt drives are employed to transmit load from the driving shaft of the motor to the driven shaft when they arc separately located. There tire two types of belting available for industrial use. 

Figure 8.10 Angle of contact with a flat-belt drive...

These are short centre drives unlike flat belt drives. The belt slip in such drives is negligible. The recommended maximum power that can be transmitted through such belts of different cross-sectional areas is provided by the belt manufacturer. The normal cross-sections of V belts in practice are given in Table 8.3. The cross-section of a belt depends upon the power to be transmitted and its speed. To select the appropriate section of the belt for the required transfer of load refer to Figure 8.11 also provided by the manufacturer. It is recommended that... 

Figure 8.12 Determining the belt details in a V-belt drive...

Questionnaire to determine the suitability of the motor shaft and the bearing for the required belt drive... 

For critical loads and belt drives particularly, the user is advised to seek the opinion of the motor manufacturer to determine the mechanical suitability of the motor selected, its shaft and the DE bearing for the load to be transmitted, according to the drive system being adopted. The following are some important parameters that may help to determine... 

Endless V-belts for industrial purposes - Industrial V-belt drives - calculation of power ratings Pulley and V ribbed belts for industrial applications-PH, PJ, PK. PL and PM profiles 2494-1/1994 3790/1995 4184 5292/1980 9982/1998... 

Direct or rigid couplings Flexible couplings Delayed-action couplings Construction and principle of operation Belt drives Checking the suitability of bearings Suitability of rotors for pulley drives... 

Pony motors are additional, small motors connected to the same fan shaft. They are typically about 1/4 the size of the full size motor. Pony motors do not lend themselves to gear box applications and are, therefore, primarily applied to belt drive applications. The big motor operates when full capacity is required and the small motor simply free wheels. At reduced capacity, the small motor operates and the big motor spins freely. 

Vane axial fans develop a greater static pressure than tube axial fans. They are constructed from a variety of materials, depending on the application. They may use either a direct drive or a belt drive. More expensive models... 

Rlemen, m. belt, band, strap, thong oar. -an-trieb, m. (Mach.) belt drive, -fett, n. belt dressing, -kitt, m. belt (or strap) cement, -leder, n. belt leather, belting strap leather, -scheibe, /. belt pulley, -setuniere, /., -schmiennittel, n. belt lubricant, -trieb, m. belt drive, belt transmission,... 

The difference between the brake horsepower and the water or liquid horsepower is the pump efficiency. The requirement in either case is the horsepower input to the shaft of the pump. For that reason, the brake horsepower represents the power required by the pump, which must be transmitted from the driver through the drive shaft through any coupling, gear-box, and/or belt drive mechanism to ultimately reach the driven shaft of the pump. Therefore, the losses in transmission from the driver to the pump itself must be added to the input requirement of the driven pump and are not included in the pump s brake horsepower requirement. 

ARR. 2 SWSI For belt drive or direct connection. Impeller overhung. Bearings in bracket supported by fan housing. 

ARR. 7 DWDI For belt drive or direct connection Arrangement 3 plus base for prime mover... 

ARR. 10 SWSI For belt drive Impeller overhung, two bearings, with prime mover inside base... 

ARR. 3 SWSI WITH INDEPENDENT PEDESTAL For belt drive or direct connection fan. Housing is self-supporting. One bearing on each side supported by independent pedestals. 

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