Operating Principle

In Figure 4, the upper disk assembly is the input assembly driven directly by the shaft of the ac induction motor at a constant speed. This constant-speed disk assembly has one stationary disk member on the left and one movable, or sliding, disk member on the right. The sliding member is mechanically attached to a positive shifting linkage arrangement consisting of a thrust hearing, bearing housing, and shifting yoke. This linkage is actuated by a control hand-wheel or some other speed-changing device.

In the same view, the lower disk assembly is the output assembly, whose speed is adjustable. In this adjustable-speed disk assembly, the sliding member is next to the spring cartridge on the left and the stationary member is on the right. Note that this arrangement is just the opposite of that for the upper, or constant-speed, disk assembly. This adjustable-speed output shaft of the drive. A flexible, wide-section, rubber V belt connects the two disk assemblies.

Assuming the minimum speed belt position as a starting point, the positive shifting linkage or the sliding member of the constant-speed disk assembly is moved to the left toward the fixed member. This positive change forces the wide-section V belt to a larger diameter in the constant-speed disk assembly. Simultaneously, the belt forces the sliding member on the adjustable-speed disk assembly against its spring so the belt assumes a smaller running, or pitch, diameter in this disk assembly. The speed of the output shaft increases in stepless increments, whereas the drive motor speed remains constant. Reversing the previous procedures reduces the output shaft speed.

When the V belt is at this maximum diameter in the constant-speed disk assembly, it is at a minimum diameter in the adjustable-speed disk assembly and the output shaft speed is at maximum. Conversely, when the V belt is at its minimum diameter in the constant-speed disk assembly, it is at a maximum diameter in the adjustable speed disk assembly and the output shaft speed is at minimum.

maximum minimum speed speed

FIGURE 4 Functional diagram for a mechanical adjustable-speed drive belt section (Reliance Electric)

maximum minimum speed speed

FIGURE 4 Functional diagram for a mechanical adjustable-speed drive belt section (Reliance Electric)

Because one member of each disk assembly is fixed on its shaft, the V belt must move axially as well as along the inclined surface of the disk to assume different diameters and cause the speed to change. Centrifugal force makes this composite movement of the belt effortless when the drive is in operation, but the speed setting of the drive must never be changed while the drive is not operating and motionless. If speed-setting change is attempted while the drive is motionless, destructive, crushing forces are imposed on the belt. These same forces may also damage the positive shifting linkage of the otherwise rugged mechanical adjustable-speed drive.

Renewable Energy Eco Friendly

Renewable Energy Eco Friendly

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable.

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