Item 0771

MAKE: SynchroLite ~ P.T. - Reduction - Secondary - Gear - Planet - 12 DP - 18 tooth

Drawing:

 

Notes:

All calculations are based on 30 horsepower engine.

The thickness of the sprocket under the teeth is less than the tooth whole depth but the rim in the middle and the extended sides (to hold the bearings) should make up for this. If a needle bearing is used then there is plenty of metal under the teeth.

FORM: Gear - Spur - Dimensions

FORM: Hamilton Spur Gear Selection

Durability increase as a result of internal gearing (Hamilton p. D-4); 3:1 ratio is factor of 2.0; 4:1 ratio is a factor of 1.66. The actual ratio is 3.52 so the factor will be 1.83. 6.4 hp * 1.83 = 11.71 hp. Safety Factor - Durability = 4 * 11.71 = 46.85. 46.85 / 29.3 = 1.60. ~or with 3 planetary gears~ 3 * 11.71 = 35.13. 35.13 / 29.3 = 1.12.This is between the planet and ring not planet and sun - I would think.

 

Safety Factor - Durability

3 planetary gears

= 3 * 6.4 = 19.2; 19.2 / 29.3

= 0.66

 

 

4 planetary gears

= 4 * 6.4 = 25.6; 25.6 / 29.3

= 0.87

 

Safety Factor - Strength

3 planetary gears

= 3 * 11.0 = 33.0; 33.0 / 29.3

= 1.13

 

 

4 planetary gears

= 4 * 11.0 = 44.0; 44.0 / 29.3

= 1.50

Gear may end up with 1 less tooth and larger pressure angle? May 17, 2000

Thrust washers could position the assembly and handle incidental thrust. An example of a special bearing arrangement of this nature is shown in [Source - MDD] Fig.32.

Use of Helical Gears: (Seriously consider using helical gears to reduce weight. - September 30, 2001)

If the above gear is produced as a helical gear then;

The durability changes from 6.4 hp to 11.7 hp. - an 83% increase.

The strength changes from 11.0 hp to 16.0 hp. - an 45% increase.

Using four planetary gears means that the total;

Durability is 46.8 hp. - a safety factor of 1.9,

Strength is 64 hp. - A safety factor of 2.6.

This means that;
  1. The weight can be reduced by the use of a narrower face width and possibly a smaller diametral pitch.
  2. A smaller diametral pitch may allow for more meat in the sun gear.

Parameters: (This is under development?)

 

 

 

 

 

 

 Normal Pressure Angle

 20

 

 

 

 

 

 

 

 

 

 

 

 

  

Source:

 

 Arrow Gear Company

C027

 High Aerospace quality

 

 Rush Gears Inc.

C047

 Prototype

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Last Revised: September 30, 2001