Uni-UAV_Intermediate

Uni-UAV ~ Power Train - Reduction - Intermediate

Overview:

Use angular spiral bevel gears.

The ratio selected for this gear will probably be dependant on the ratio that is obtainable for the final gear set.

Alternative A is a pinion and crown.

Alternative B is 2 pinions and 2 crowns, which have had the teeth machined off for half the face widths/

Drawing:

Alternative B; Through X-shaft:

This is only here for reference. It is the desired pitch and is spiral but has fewer teeth than the gear set in the Hamilton table below. It's power specifications are noted in the arrow table below.

Alternative B; Split X-shaft:

The above ratio is 3:1.This allows for a minimum angle of approximately 140º between the 2 output shafts. The 2:1 ratio will allow for a larger angle but it would never be required.

Working Papers:

DESIGN:

MAKE:

Items:

DESIGN:

	Name	Item
	Uni-UAV ~ Power Train - Reduction - Intermediate - Through X-shaft - Assembly
	Uni-UAV ~ Power Train - Reduction - Intermediate - Split X-shaft - Assembly

MAKE:

	Name	Item

BUY:

	Name	Item

Reference only:

This is for 2:1 for the basic and smallest Arrow gear 10.0 PD, 16/32 tooth. 10P32L16 & 10P16R32

FORM: Arrow Spiral Stock Gear Selection. Diametral pitch is 10

Horsepower:	22.6	hp
Pinion Speed:	7734	rpm
Pinion Working Torque:	184	in-lb
Estimated Rated Pinion Torque:	368	in-lb
Catalog Rated Pinion Torque:	410	in-lb
Catalog Pinion Pitch Diameter:	1.6	in
Pitch Line Velocity:	3242	ft/min
Dynamic Factor:	0.7603
Allowable Pinion Torque:	312	in-lb
Service Factor:	1.69	:1

This is too strong for Alternative A, through X-shaft. It may be OK, or too light, for for Alternative B, Split X-shaft.

Alternative A; Through X-shaft:

This is used with a through X-shaft and the overrunning clutch will be located between this crown gear and the X-shaft.

For the gear 12 PD, 2:1 ratio18/36 tooth. Spiral bevel

The gear info is taken from Rush gears p.554 and have straight teeth, however the calculations below are for spiral bevel gears.

FORM: Hamilton Bevel Gear Selection.

Pinion Speed	7734	rpm
Catalog Pinion Pitch Dia.	1.5	in.
Pitch Line Velocity	3039	ft/min
Diametral Pitch	12
Face Width	.53	in
Allowable Contact Stress	200,000	Steel Rockwell C 55 min.
Allowable Bending Stress	135,000	Steel Rockwell C 50 min.
Elastic Coefficient	Pinion & Gear - Steel
Load Distribution Factor	Neither member straddle mounted
Geometry Factor [I]	.100
Geometry Factor [J]	.230
Durability	28.2	hp. Service factor is 1.25
Strength	17.65	hp. Service factor is 0.78
See form for additional data.

Alternative B; Split X-shaft:

This is used with a split X-shaft and the overrunning clutch will be located in the driven sheave.

For the gear 10 PD, 2:1 ratio 20/40 tooth. Spiral bevel

The gear info is taken from Rush gears p.553 and have straight teeth, however the calculations below are for spiral bevel gears.

For the modified gear 10 PD, 20/40 tooth. Spiral bevel

The face width has been cut in half from 0.70 to 0.35

FORM: Hamilton Bevel Gear Selection.

Pinion Speed	7734	rpm
Catalog Pinion Pitch Dia.	2.0	in.
Pitch Line Velocity	4053	ft/min
Diametral Pitch	10
Face Width	.36	in
Allowable Contact Stress	200,000	Steel Rockwell C 55 min.
Allowable Bending Stress	135,000	Steel Rockwell C 50 min.
Elastic Coefficient	Pinion & Gear - Steel
Load Distribution Factor	Neither member straddle mounted
Geometry Factor [I]	.102
Geometry Factor [J]	.245
Durability	34.5	hp. Service factor is 3.1 ⁽¹⁾
Strength	19.7	hp. Service factor is 1.74 ⁽¹⁾
See form for additional data.

(1) The horsepower going to each rotor is only 11.3. The Service factors take this into account

Spiral Bevel Gears Reduction:

Same Page ~ Different Craft:

Related Pages this Site:

Introduction Page | Uni-UAV Home Page | UniCopter Home Page | Nemesis Home Page | SynchroLite Home Page

Latest revision; August 30, 2007