S_Hub_CVJ

SynchroLite ~ Rotor - Hub - 3-blade - Constant Velocity Joint w/ Hub Spring

(Concentric Double Universal Joint & Hub Spring)

Picture of Preliminary Mockup:

Objective:

To provide more control authority than that of a conventional 2-blade teetering rotor.

To significantly reduce the cyclical Corollas effect, which is the primary reason for lead-lag hinges?

To reduce vibration

Overview of Hub Concept:

OTHER: Flight Dynamics - Rotor Hub - Constant Velocity Rotor w/ Hub Spring

Comparison of the SynchroLite's CVJ+HS Rotor and the UniCopter's Absolutely Rigid Rotor:

The blades of both helicopters require a high degree of rigidity; but: A blade's thrust is a function of it's angle of attack and it's angle of attack is a function of its pitch. Therefore the teetering of this rotor removes pitch and therefor lower moments are generated by the blade than would be generated by the UniCopter's blade. Note that the fixed azimuth spring may occasionally add to the moment.

In other words; if the hub spring on this rotor were 'frozen' the craft would behave similar to the Absolutely Rigid Rotor; until the stresses destroyed it.

Concerns:

The CVJ will remove the greatest tendency to lead/lag. However, can the mast structuarly handle the lead/lag loads (cyclical Corrolis) created by out-of-plane blade flexure due to the flapping resistance from the hub spring.?

Will the loads on the pitch bearings be so high that they will effect the ease of moving the control sticks?

Temporary Working Notes:

Increase the diameter of the mast?

The blades should be removable for transportation.

Working Papers:

DESIGN:

B433

MAKE:

B434

Items:

The pages below that have the indicator [], are the ones that are applicable to current prototype.

DESIGN:

	Name	Item
	Rotor - Hub - 3-blade - CVJ+HS - Overview & Layout	1350
	Rotor - Hub - 3-blade - CVJ+HS - Blade Generated Forces - Preliminary	1332
	Rotor - Hub - 3-blade - CVJ+HS - Blade Generated Forces - Intermediate	Ref.1163
	Rotor - Hub - 3-blade - CVJ+HS - Blade Generated Forces - Advanced
	Rotor - Hub - 3-blade - CVJ+HS - Load Distribution This is where the info from the above 3 lines will go	Ref.1193
	Rotor - Hub - 3-blade - CVJ+HS - Bearings - Pitch	1409
	Rotor - Hub - 3-blade - CVJ+HS - Bearing - Mast - Thrust & Teeter	1385
	Rotor - Hub - 3-blade - CVJ+HS - Hub Spring	0799
	Rotor - Hub - 3-blade - CVJ+HS - Hub Spring - Azimuth Teeter	1331
	Potential Future Elastomeric Pitch Bearings:
	Rotor - Hub - 3-blade - CVJ+HS - Bearing - Elastomeric - Pitch - Angular	1326
	Rotor - Hub - 3-blade - CVJ+HS - Bearing - Elastomeric - Pitch - Radial	1327
	Rotor - Hub - 3-blade - CVJ+HS - Bearing - Elastomeric - Pitch - Combined Angular & Radial	1340
	Previous Concepts ~ Based on the Use of Elastomeric Mast Bearing(s)
	Rotor - Hub - 3-blade - CVJ+HS - Overview & Layout	1333
	Rotor - Hub - 3-blade - CVJ+HS - Bearing - Mast - Thrust & Teeter	1328
	Rotor - Hub - 3-blade - CVJ+HS - Bearing - Mast - Torque. A separate torque and positioning device	1329
	Rotor - Hub - 3-blade - CVJ+HS - Bearing - Mast - Negative Thrust	1330
	Rotor - Hub - 3-blade - CVJ+HS - Bearing - Mast - Combined. Prototype.	1341

MAKE:

		Name		Item
		Rotor - Hub - 3-blade - CVJ+HS - Final Assembly		1378
		Rotor - Hub - 3-blade - CVJ+HS - Crown Assembly		1420
		Rotor - Hub - 3-blade - CVJ+HS - Crown		1379
		Rotor - Hub - 3-blade - CVJ+HS - Hub Spring Retainer		1405
		Rotor - Hub - 3-blade - CVJ+HS - X-outer		1380
		Rotor - Hub - 3-blade - CVJ+HS - X-inner		1381
		Rotor - Hub - 3-blade - CVJ+HS - Bisector		1382
		Rotor - Hub - 3-blade - CVJ+HS - Mast HS Ring		1400
		Rotor - Hub - 3-blade - CVJ+HS - Hub Spring		1384
		Rotor - Hub - 3-blade - CVJ+HS - Grip		1397
		Rotor - Hub - 3-blade - CVJ+HS - Spindle		1426
		Rotor - Hub - 3-blade - CVJ+HS - End Cap		1418
		Rotor - Hub - 3-blade - CVJ+HS - Insert		1407
		Rotor - Hub - 3-blade - CVJ+HS - Pitch Bearing - Elastomeric - General		0801

BUY:

	Name	Item
	PT - Bearing - Ball - Angular Contact 40 degrees (& 30 degrees)	0987
	PT - Bearing - Ball - Deep Grove - 22 mm ID; 56 mm OD	1423
	PT - Bearing - Ball - Deep Grove - 25 mm ID; 52 mm OD	1196

Re: TOOLS:

	Name	Item
	DESIGN: SynchroLite ~ Special Tool - Rotor Hub - Bearing - Elastomeric - Shim Die	0802
	DESIGN: SynchroLite ~ Special Tool - Rotor Hub - Bearing - Elastomeric - Composite Shim	0803

OTHER:

	Name	Item
	OTHER: Mechanical - Bearing - Elastomeric	B332

Same Page ~ Different Craft: ~ Dragonfly ~ UniCopter

Last Revised: May 24, 2008