1318

Item 1318

DESIGN: SynchroLite ~ Power Train - 1 Engine - Bearing - Selection Process, for Assy Item 1316 -- 2 Gear Sets & 1 Belt -- Idea 10

Overview:

Safety Factor:

Other: Mechanical - Safety Factor ~ Bearings

All the following must be revised.
Brg 1: Upper mast bearing. Located below swashplate.

Speed:- The housing 0 RPM, inner race (rotor) 600 RPM = bearing 600 RPM.

This bearing will have no axial loads. The radial loads will be subject to the additional force caused by the hub spring. The titanium mast cannot be hardened therefor the bearing(s) will have to have an inner race. Consider needle bearing with inner race or a 'stack' of light radial ball bearings.

The following table and notes is taken from the 2-engine SynchroLite. They must be updated.

	Item 0593	1 only	Fafnir 2MM9307WI CR	99%	664 hrs.
	Item 0593	1 only	Fafnir 2MM9307WI CR	98%	1043 hrs.

This one looks too light. Consider 2 or one series bigger. This may be OK since loading is intermittent and bearing is rubber mounted.

Brg 2: Upper transmission bearing. Positions the crown gear, transmits lift from rotor to the power train and supports rotor during ground transportation.

Speed:- The outer race 0 RPM, inner race (rotor) 600 RPM = bearing 600 RPM.

This is a critical bearing re rotor-rotor reliability.

What load and direction do the spiral bevel gears apply?

The following table and notes is taken from the 2-engine SynchroLite. They must be updated.

	Item 0525	1 only	Fafnir 2MM207WI	99%	429 hrs.
	Item 0525	1 only	Fafnir 2MM207WI	98%	675 hrs.
	Item 0654	1 only	Fafnir 2MM307WI-CR	99%	968 hrs.
	Item 0654	1 only	Fafnir 2MM307WI-CR	98%	1521 hrs.
	Item 0778	1 only	Fafnir 2MM208WI	99%	1121 hrs.
	Item 0778	1 only	Fafnir 2MM208WI	98%	1762 hrs.
►	Item 0840	1 only	SKF QJ 208 (4-point brg)	99%	1701hrs.
	Item 0840	1 only	SKF QJ 208 (4-point brg)	98%	2673 hrs.

0525 (.7 lb ea) may be too light. 0654 (1.0 lb ea) may be good @ 99%.

Use 4-point contact bearing [Item 0840], like Bell 47, to take axial loads in both directions and thereby eliminate need for bearing 1. Disadvantage - Mast must have greater initial diameter and more machining to accept bearing inner race locking nut plus the above bearing must have a slightly larger ID.

Item 0778 and Item 0840 bearing have a larger ID and a locking nut holds down the inner race.

Consider using smaller SKF QJ 207 if power train must be reduced in size.

Brg 3: Lower transmission bearing.

Speed:- The housing 0 RPM, inner race (rotor) 600 RPM = bearing 600 RPM.

No axial load since mast will float in this bearing. The only axial load might come from the transmission, but why?

What load and direction do the spiral bevel gears apply?

The following table and notes is taken from the 2-engine SynchroLite. They must be updated.

	Item 0655	1 only	Fafnir 2MM9107WI	99%	304379 hrs.
	Item 0655	1 only	Fafnir 2MM9107WI	98%	534882 hrs.

Use this stronger bearing for the same reason as note at the end of bearing X.

Brg 4: Input Shaft Starboard Outer Bearing.

Speed:- The housing 0 RPM, inner race 1818 RPM = bearing 1818 RPM.

Takes axial and radial loading? Not sized yet.

	Item xx	1 only	xx	xx%	xx hrs.
	Item xx	1 only	xx	xx%	xx hrs.

Brg 5: Input Shaft Starboard Inner Bearing.

Speed:- The housing 0 RPM, inner race 1818 RPM = bearing 1818 RPM.

Takes axial and radial loading? Not sized yet.

	Item xx	1 only	xx	xx%	xx hrs.
	Item xx	1 only	xx	xx%	xx hrs.

Brg 6: Input Shaft Port Outer Bearing.

Speed:- The housing 0 RPM, inner race 1818 RPM = bearing 1818 RPM.

Takes axial and radial loading? Not sized yet.

	Item xx	1 only	xx	xx%	xx hrs.
	Item xx	1 only	xx	xx%	xx hrs.

Brg 6: Input Shaft Port Inner Bearing.

Speed:- The housing 0 RPM, inner race 1818 RPM = bearing 1818 RPM.

Takes axial and radial loading? Not sized yet.

	Item xx	1 only	xx	xx%	xx hrs.
	Item xx	1 only	xx	xx%	xx hrs.

Last Revised: February 03, 2005