SPEED SELECTOR Adjustable Center Drives

Adjustable center drive packages consist of a spring-loaded pulley mounted on the motor shaft, a fixed diameter companion sheave mounted on the driven shaft, a variable speed belt running between the pulley and sheave, and a sliding motorbase upon which the motor is mounted.

Typically these drives are used for output speed reduction such that a 1:1 ratio exists between the motor and driven shafts, when the belt is set at the highest possible pitch diameter on the spring-loaded driver pulley, and the center-distance between the motor shaft and driven shaft is at its minimum (shortest) distance.

Output speed is reduced by turning the handwheel on the sliding motorbase, which pulls the motor away from the driven shaft, and forces the belt to a lower pitch diameter on the spring-loaded driver pulley.

Conversely speed is increased by turning the handwheel on the motorbase, which pushes the motor closer to the driven shaft, and allows the spring-loaded pulley to force the belt to a larger pitch diameter.

Series 8800 Adjustable Center Drives

*HP
Rating Model
Number Pitch Diameters
Max - Min Belt &
Sheave Size

1 8816 6.3 - 2.1 1422V

3 8827 .5 - 2.57 1922V

5 8859 9.3 - 3.1 2322V

10 8810 10.2 - 3.4 3226V

10 8813 12.6 - 4.2 4430V

20 8822-2 10.0 - 4.0 3230HV

20 8822-2.75 10.0 - 4.0 4430V

20 8821 11.6 - 3.8 4430V

20 8823 12.6 - 4.2 4430V

25 812W 12.0 - 6.0 4430V

25 812S 12.0 - 6.0 3230HV

30 8833 12.6 - 4.2 4430V

40 8843 12.6 - 6.3 4836V

50 8854 13.4 - 6.8 4836V

100 8899 15.1 - 7.5 4836V

* HP Rating based upon 1750 Rpm input.

Series 800 Adjustable Center Drives

*HP
Rating Model
Number Pitch Diameters
Max - Min Belt &
Sheave Size

1 816 6.3 - 2.1 1422V

3 827 7.5 - 2.5 1922V

5 859 9.3 - 3.1 2322V

10 810 10.2 - 3.4 3226V

20 821 11.6 - 3.8 4430V

30 833 12.6 - 4.2 4430V

* HP Rating based upon 1750 Rpm input.

Series 21 Adjustable Center Drives

*HP
Rating Model
Number Pitch Diameters
Max - Min Belt &
Sheave Size

1/4 3M 2.8 - 1.4 A

1/2 4M 3.7 - 1.85 A

1 5M 4.7 - 1.85 A

1-1/2 6M 5.7 - 2.15 A

1-1/2 7M 6.75 - 2.5 B

4 8-1-M 7.78 - 2.8 B

* HP Rating based upon 1750 Rpm input.

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SPEED SELECTOR, Inc

Tel: 440-543-8233 . Fax: 440-543-8527
17050 Munn Road, Chagrin Falls, Ohio 44023 USA