//Variable Speed Drives
Variable Speed Drives2018-04-19T20:35:33+00:00

Variable Speed Drives

  • Very economical and reliable method of speed change
  • Allows the user to find the ideal speed without changing sheaves and belts; especially important on applications where final driven speed is critical and difficult to attain with two fixed-diameter sheave
  • Speed range within the ratio is infinite, and speed change is accomplished quickly, while the drive is running
  • Can be used as a highly efficient belt tensioner, with no adjustment necessary
  • Offers a form of “soft start,” eliminating belt slip and premature wear
  • On belt drives with inherent high torque start-up requirements
Variable Speed Drives

Resources

Variable Speed Drives Product Information

Why Vary Speed?

Variable speed drives are needed because many applications are not run at the same speed all of the time, due to the surrounding conditions. Revolutions per minute (RPM) of the driven shaft need to be increased or decreased when there are changes in load conditions, application requirements, or other circumstances.

Variable speed belt drives achieve the versatility needed to maximize application efficiency and productivity while remaining an inexpensive solution. In the most typical installation, a belt connects a variable speed pulley to a driven sheave. The pulley is mounted on a motor shaft and the motor is at constant speed. Thus, the speed at the driven shaft is a ratio of the pitch diameters of the pulley and sheave.

Please download catalog for sizing instructions and dimensional data.

Variable Speed Drive Additional Resources

Econoline Series

  • Reliable, proven, maintenance-free design at an economical cost
  • Ideal for both adjustable and fixed center drives using classic “A” and “B” (or 4L and 5L) section drive belts
  • Driven speed ratios from 1.6 to 1 up through 2.7 to 1
  • Horsepower ranges from fractional through 5 HP @ 1750 RPM motor speed
  • Durable cast iron flanges; wide selection of models available
  • Typical applications: conveyors, mixers, small machine tools, mower traction drives, printing equipment, packaging machines, and belt tensioners

Aluminoline Series

  • Best possible belt alignment with the least amount of overhung load
  • Used with “A” and “B” drive belts
  • Anodized aluminum flanges – quite operation with minimum vibration
  • Rated for .33 HP through 1.5 HP motors
  • Two-sided; speed ratios up to 2.75 to 1
  • Corrosion-resistant; applications include: agricultural machinery, food packaging and bottling equipment, baseball pitching machines, and much more

WB Series

  • Two-sided moveable pulley; uses wide variable speed belts for the most efficient transmission of torque through the widest possible speed range.
  • Best possible belt alignment when used with a grooved companion sheave
  • Maximum service when lubricated through convenient grease fitting
  • 6 to 13 inches in diameter; capable of handling up to 15 HP
  • Durable cast iron flanges (over 1 HP), corrosion-resistant anodized aluminum flanges (under 1 HP)
  • Application include: conveyors, printing presses, mixers, packaging and bottle-filling machines, machine tools, and agricultural equipment.

Hi-Ratio Series

  • Unique combination of broader driven speed ranges and lowest possible minimum driven speed
  • Three drive packages available
  • Horsepower ranges from 0.5 to 5, with a 1750 RPM motor
  • Speed ratios up to 11.5 to 1
  • Ideal for use on machine tools and mixing machines

Adjusta-Sheave Series

  • Cost-saving alternative to a spring-loaded pulley when speed change is infrequent
  • To change speeds, drive must be shut down (unlike other variable speed pulleys)
  • All models use wide variable speed belts
  • Eliminates need for internal drive keys – providing more efficient transfer of power and longer life
  • Two cast iron flanges are movable, allowing perfect belt alignment at all times
  • Four models available – 5 to 30 HP; speed ratios up to 2.5 to 1
  • Applications include: textile spinning frames, heating and air conditioning equipment, and pumps
 

Adjustable Motor Bases

  • Four models to change distance between the motor and driven shaft
  • Sliding “SMB” Type – extremely low profile, strong, and lightweight
  • Sliding Cast Iron Type – original Lovejoy design, durable cast iron and steel
  • Sliding Dovetail Type – most compact, most economical Lovejoy motor base
  • Tilting Type – Economical base; features pivotal rather than sliding movement
 

Companion Sheaves

  • Flat and grooved types for variable speed belts
  • Grooved sheaves machined to match belt width and angle of standard belts
  • Made of durable cast iron to assure best possible wear at belt contact area
  • Bored to accept standard type tapered bushings
  • Precision balanced for smooth running

Variable Speed Belts

  • Designed for long life, even tracking, smooth & efficient operation
  • Made of special synthetic compound for maximum environmental resistance
  • 7/8 through 2-3/4 inch top width
  • Maximum recommended belt speed is 5,600 ft/min

Wind Up

Misalignment Capability

 

at Max

Max
Angular

Max Parallel
Offset

Max Rec
End Play

Max
Torque

HP/100

Max
Speed

Size

Torque*

Offset

in

mm

in

mm

in-lb

Nm

RPM

RPM

18 Reg

1.80°

3.0°

0.008

0.20

0.010

0.25

18

2.0

0.03

30,000

25 Reg

1.80°

4.5°

0.011

0.28

0.020

0.51

34

3.8

0.05

30,000

37 Reg

1.78°

4.5°

0.014

0.36

0.020

0.51

39

4.4

0.06

30,000

50 Reg

1.82°

4.5°

0.021

0.53

0.035

0.89

82

9.3

0.13

30,000

62 Reg

0.85°

3.0°

0.019

0.48

0.035

0.89

126

14.2

0.20

20,000

75 Reg

1.82°

4.5°

0.028

0.71

0.040

1.02

175

19.8

0.28

20,000

87 Reg

1.68°

4.5°

0.035

0.89

0.040

1.02

346

39.1

0.55

10,000

100 Reg

1.03°

3.0°

0.030

0.76

0.040

1.02

565

63.8

0.90

6,000

125 Reg

1.85°

4.5°

0.044

1.12

0.040

1.02

755

85.3

1.21

6,000

137 Reg

1.85°

3.0°

0.035

0.89

0.040

1.02

1,260

142.4

2.02

6,000

150 Reg

0.85°

3.0°

0.041

1.04

0.040

1.02

1,890

213.5

3.02

3,000

25 Short

1.07°

3.0°

0.007

0.18

0.015

0.38

34

3.8

0.05

30,000

37 Short

1.09°

3.0°

0.009

0.23

0.015

0.38

39

4.4

0.06

30,000

50 Short

1.05°

3.0°

0.014

0.36

0.010

0.25

82

9.3

0.13

30,000

62 Short

0.85°

3.0°

0.019

0.48

0.020

0.51

126

14.2

0.20

20,000

75 Short

1.12°

3.0°

0.019

0.48

0.020

0.51

175

19.8

0.28

20,000

87 Short

1.17°

3.0°

0.024

0.61

0.020

0.51

346

39.1

0.55

10,000

100 Short

1.03°

3.0°

0.030

0.76

0.020

0.51

565

63.8

0.90

6,000

125 Short

1.22°

3.0°

0.030

0.76

0.020

0.51

755

85.3

1.21

6,000

137 Short

1.35°

3.0°

0.350

0.89

0.020

0.51

1,260

142.4

2.02

6,000

150 Short

0.85°

3.0°

0.041

1.04

0.020

0.51

1,890

213.5

3.03

3,000

Note: * Total backlash is approximately 1/3 of windup at max torque – consult Lovejoy Engineering for more information.

Please see downloadable Specialty Products catalog for dimensional data.

For other coupling types: see Coupling Preselection Guide