Item 1147

DESIGN: Dragonfly ~ Power Train - Reduction - Initial - Gear Selection

FORM: Arrow Spiral Stock Gear Selection. 90 degrees, From Arrow catalog.

Black text columns are ratio of 3:2.

Blue and green text columns are ratio of 2:1

Bold red is the choice. Bold green was the choice. Bold black was/was the choice. Bold blue was/was/was the choice.

 

Ratio:

1.5:1

1.5:1

2:1

2:1

2:1

2:1

2:1

 

Arrow Pinion Part No.

8P24L16

7P24L16

9P34L17

9P34L17

8P36L18

8P36L18

8P36L18

Item xxxx

Item xxxx?

Item xxxx?

Item xxxx?

Item 0923

Item 0923

Item 0923

 

Arrow Gear Part No.

8P16R24

7P16R24

9P17R34

9P17R34

8P18R36

8P18R36

8P18R36

Item xxxx

Item xxxx

Item xxxx

Item xxxx

Item 0924

Item 0924

Item 0924

 

Horsepower;

50.0

50.0

50.0

50.0

50.0

50.0

70.0

 

Pinion Speed:

5500

4500

5250

4700

5500

4500 4700?

4771

 

Pinion Working Torque:

573

700

600

670

573

700

925

 

Estimated Rated Pinion Torque:

1145.9

1401

1200

1341

1145.9

1400.6

1849

 

Catalog Rated Pinion Torque:

601

863

644

644

1176

1176

1176

 

Catalog Pinion Pitch Diameter:

2.0

2.286

1.889

1.889

2.25

2.25

2.25

 

Pitch Line Velocity:

2882

2695

2598

2326

3242

2653

2813

 

Dynamic Factor:

0.7696

0.7748

0.7777

0.7861

0.7603

0.7761

0.7715

 

Allowable Pinion Torque:

462

669

500

506

894

913

907

 

Service Factor:

0.8073

0.9549

0.8344

0.7550

1.5605

1.3033

0.9812

 

Weight: (of set)

1.38 lb.

2.37 lb.

2.25 lb.

2.25 lb.

3.49 lb.

3.49 lb.

3.49 lb.

FORM: Hamilton Bevel Gear Selection.

Bold red is the choice. Bold green was the choice. Bold black was/was the choice. Bold blue was/was/was the choice.

 

Ratio:

2:1

2:1

2:1

1.5:1

2:1

 

 

Gear Set:

9P34L17 / 9P17R34

8P36L18 / 8P18R36

8P36L18 / 8P18R36

7P24L16 / 7P16R24

8P36L18 / 8P18R36

rpm

 

Item Number:

 

0923 / 0924

0923 / 0924

 

0923 / 0924

 

 

Pinion Speed

5250

4700

4500

4500

4771

rpm

 

Catalog Pinion Pitch Dia.

1.889

2.25

2.25

2.286

2.25

in.

 

Pitch Line Velocity

2598

2770

2770

2695

2813

ft/min

 

Diametral Pitch

9

8

8

7

8

 

 

Face Width

0.625

0.8125

0.8125

0.6875

0.8125

in

 

Allowable Contact Stress

190,000

190,000

190,000

190,000

190,000

Steel Rockwell 50 min.

 

Allowable Bending Stress

30,000

30,000

30,000

30,000

30,000

Steel Rockwell C 55 min.

 

Elastic Coefficient

Pinion & Gear - Steel

Pinion & Gear - Steel

Pinion & Gear - Steel

Pinion & Gear - Steel

Pinion & Gear - Steel

 

 

Load Distribution Factor

Both straddle mounted

Neither straddle mounted

Neither straddle mounted

Neither straddle mounted

Neither straddle mounted

 

 

Geometry Factor [I]

.098

.099

.099

.082

.099

 

 

Geometry Factor [J]

.225

.232

.232

.190

.232

 

 

Durability

39.9

(1) 50.5

(1) 50.5

36.6

53.6

hp. Service factor is 1

 

Strength

60.6

(1) 72.7

(1) 72.7

56.6

77.0

hp. Service factor is 1

 

Comments:

To be used with 3.67:1 or 4:1 secondary

To be used with 3.67:1 or 4:1 secondary

To be used with 3.67:1 or 4:1 secondary

To be used with 4.33:1 secondary

To be used with 3.67:1

 

 

See form for additional data.

 

 

 

 

 
  1. The weight and the safety factor can be reduced by decreasing the face width.

Notes:

By using the larger gear we can probably negate the need for bearings on the driven shaft and have this shaft (tube with spline on the inside) mount of the stub shafts of the two secondary gear pinions. 'Close fit' spline.

Consider designing the box so it will accept a slightly larger ratio gear set also.

Miscellaneous:

For comparison see: OTHER: Helicopter - Outside - Intermeshing - Kaman - K-MAX

Gear calculations for outside helicopters: DESIGN: SynchroLite ~ Power Train - Secondary Reduction

To:

The information from here goes to: DESIGN: Dragonfly ~ Power Train - Bearing - Initial Box - Load Calculations

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Last Revised: November 12, 2003