Item 0991

 

DESIGN: SynchroLite ~ Rotor - Hub - 2-blade Teetering - Teetering Bearing & Axle

Outside Helicopter

Robinson:

Bearing: R22 appears to use a journal bearing. See hard copy of Maintenance Manual pages.

Axle: R22 uses a MS21250-10-80 bolt. (see zerox of page from BCIT Robinson maintenance manual). I think this is 5/8" diameter. The cross sectional area is 0.3069 sq-in. and the helicopter's gross weight is 1370 lbs. They also have a second lower smaller bolt that appears to give support also.

Bell:

Bearing: The 47 and 206 use ball bearings.

Hiller:

Bearing: Could go to BCIT and look up the information in the FH-1100 service manual.

Mini 500:

Bearing: Appears to be a spherical bearing with a 1.4375" OD. The Heim catalog show one (of possibly many bearing with this OD to have an 3/4" ID and a maximum static radial load of 25,750 lbf. The weigh is 0.21 lbs each, which will be about 4 lbs for the CDUJ hub. Check the Mini 500 CD disk for additional information.

Axle: Look in up on the CD ROM It may be 1/2' to 5/8" dia. since a 3/8" dia. bolt is used to retain it.

Indian:

Bearing: It uses 2 Torrington B810 needle roller bearings. 1/2" diameter bore, 0.625 wide, full compliment.

Axle: The axle is a 1/2" MS bolt. The cross sectional area is 0.1964 sq-in. and the helicopter's gross weight is 527 lbs.

SynchroLite

 Bearing:

Consider Torrington B-66 (item 0470)

Consider elastomeric bearing.

Better yet seriously consider Rexnord Tuflite composite bearings with unique journal bearing bores on; OTHER: Mechanical - Bearing ~ Teetering Bearing

 Axle:

The SynchroLite has a gross weight of 550 lbs., divided over 2 masts.

5/16" diameter has a 0.0767" cross sectional area.

3/8" diameter has a 0.1105" cross sectional area.

7/16" diameter has a 0.1504" cross sectional area.

Have used a 3/8" diameter bolt, to reduce size but also include lower smaller bolt for additional support. This lower bolt will be down in the mast where there is no cutout for pitch linkage? Consider using this lower bolt to attach the upper scissors to the mast. Also consider it for attaching flapping restrainer.

Probably should use a 5/16" diameter bolt, which looks optimal. For calculations see: DESIGN: SynchroLite ~ Rotor - Hub - 3-blade CVJ & HS - (CDUJ) - Bearing - Mast - Thrust & Teeter Note that the additional safety factor for the Robinson is 4.5:1 and that the SynchroLite with a 5/16" bolt has a better additional safety factor at 6.9:1

For Hardware (nuts and bolts etc.) see; OTHER: Mechanical - General - Hardware

DESIGN: SynchroLite - Rotor - Hub - Teetering Bearing w/ Hub Spring may be a better idea.

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Last Revised: November 3, 2004