Prime Mover

1.  

Type - electric motor or engine, for example 4 cylinder internal combustion engine

2.

Power rating in kW

3.

Output speed. If variable, indicate speed range and frequency of variable.

4.

Dimensions of prime mover.

 Driven Machine

1.

Type, for example, kiln, conveyor, etc.

2.

Power rating in kW

3.

Speed

4.

Service - hours per day, running time in any hour, details of reversals if applicable, type of loading, ambient temperature, etc.

  
Gear Unit

1.

Type, for example, H2.

2.

Size, for example, 315.

1.

Gearbox Type

1.1

Parallel shaft type is specified - type H.

1.2

Ratio =1500÷365
 =4.11, type H1 (single reduction)

2.

Mechanical Capacity

2.1

From table 3 on previous page  the application is moderate shock.

2.2

From table 1 on page 3 the service factor is 1.5.

2.3

The required mechanical capacity = 1.5 x 725 = 1088 kW

2.4

Under mechanical ratings a unit size 315, nominal ratio 4.13, has a capacity of 1293 kW

3.

Thermal Rating Check

3.1

From table 2 on previous page  the thermal service factor for 30⁰C ambient temperature and 100% running time is 0.9 for a unit with fan cooling (reference to the thermal ratings shows that at least fan cooling is required.)

3.2

The required thermal capacity = 725 - 0.9 = 806.

3.3

Under thermal ratings, fan cooled, a size 315 has a capacity of 918 kW at 1500 rpm, ratio 4.15

4.

Check that the exact ratio.

5.

Order a gearbox type H1 - 315 exact ratio 4.15 with cooling fans fitted.

1.

Gearbox Type

1.1

Foot shaft mounted unit with right angle shafts.

1.2

Ratio = 1500÷80 = 18.8, type B2SF could be used

2.

Mechanical Capacity

2.1

From table 3 on page 10 the application is uniform load.

2.2

From table 1 on page 3 the service factor is 1.25

2.3

The required mechanical capacity = 1.25 x 465 = 581 kW

2.4

Under mechanical ratings a unit size B3SF - 400, nominal ratio 18.9, has a capacity of 620 kW. The double reduction type B2SF - 400 ratio 18.9 has insufficient mechanical capacity.

3.

Thermal Rating Check

3.1

From table 2 on previous page  the thermal service factor for 20⁰ C. ambient temperature and 100% running time is 1.0

3.2

The required thermal capacity = 465÷1.0 = 465 kW.

3.3

Under thermal ratings, fan cooled, a size 400 at 1500 rpm has a capacity of 484kW

4.

Check that the exact ratio.

5.

Order a gearbox type B3SF - 400, exact ratio with cooling fans fitted.

p

 = 

kW x 9545 x K ÷ N x R

Where P

 = 

equivalent overhung load in kN,

kW

=

power carried by the shaft,

N

=

rpm of the shaft

R

=

pitch radius of sprocket, pinion,

sheave or pulley (mm).

 K Factor

Sprocket for chain

1

Spur gear

1.25

V belt sheave

1.5

Flat belt pulley

3.0

  
Notes :

1.  

Values are calculated for the most unfavourable direction of rotation. Consult us with specific application details.

2.

3.

For overhung load and axial thrust values for large sizes consult us.