1514

Item 1514

DESIGN: SynchroLite ~ Power Train (for 1 engine) - Assembly - Layout - Ball - Worm & Wormgears

Overall Objective:

To produce an intermeshing helicopter that only requires a total of three gears for reduction and power transmission.

The helicopter would be powered by a single engine or a single electric motor. The SynchroLite is designed to be lightweight. The ball-worm & gear may, hopefully, result in a further weight reduction.

Perhaps the 2-blade rotor with high twist might be better for lift/power than the 3-blade CVJ, if the intent is to meet the Ultralight catigory and/ or use electric power.

FORGET ~ June 9, 2006. ~ There are approximately a dozen patents for ball-worm and gear reduction, however, I have only been able to find one product that utilizes it. It appears, to me at least, that there exists a problem with ball scuffing and speed limitation. Consider a 3-gear hypoid or 6-gear spiral bevel gearbox instead.

DO NOT QUITE FORGET ~ April 13, 2008

It may be possible to use a 9:1 ratio. This will provide better efficiency and allow for back driving, which may be required for autorotation.

Consider using balls between the worm and the two wormgears for normal powering and a sliding action for any 'back driving' from gear to worm. See section One Way Ball Drive: below.

Drawing:

Notes:

A single reduction that will be somewhere between 6:1 and 10:1. More specifically; between 8.8:1 and 9.8:1 .

A flexible coupling would be located between the electric motor and the ball-worm & wormgears gearbox.

An overrunning clutch will be located within or adjacent to the flexible coupling.

Power Train:

Rotors: ⁺/_-600 rpm.

Transmission: Ratio ⁺/_- 10:1 For concept see; DESIGN: UniCopter - Power Train - Alternative Idea - Ball-Worm & Gear Reducer

Motor: ⁺/_-6000 rpm

Autorotation: Synchronization is by back driving through 10:1 Ball-Worm & Wormgears

Hans mentioned that a large diameter worm (so that the motor could be located inside) would result in very narrow teeth for the same ratio. Forget this idea.

Possibly consider two or more ball tracks. This will make the ball tracks more complex but it might mean that more (but smaller) balls are taking the load.

One Way Ball Drive:

Thoughts:

Having the worm drive the two wormgears with the balls will significantly increase the efficiency of a worm & gear reducer.
However, it would appear that back-driving the worm from the wormgears will only be done during autorotation and in this flight mode the reducer is only used to synchronize the two rotors.
This use of balls for only one-way power transmission should simplify the design.
This sketch shows the worm's teeth, the balls, and the teeth of one gear.

Simplistically, this could be view as a double-thread worm with one of the threads machined off. In addition, every second tooth on the wormgears will be machined off.

Both wormgears could have large bores to accommodate large diameter masts. The pitch rods could then go up the center of the mast to the 2 or 3 blades, ala Fetters.

A Sprag clutch would be located on the input shaft of the worm.

A flexible coupling would be located between the engine and the worm's shaft.

Concerns

Is the 7.3152 m/s speed of the ball's too fast?

If the balls do not flow in their tracks the rotors will loose synchronization.

If a ball 'jambs' the gearbox may be destroyed. Could the adding of a separate synchronization device overcome the problem?

Considerations:

The effectiveness of the ball and ball track in the worm & wormgears. THIS IS THE BIG ONE SINCE THE WHOLE CONCEPT IS BASED ON THE ABILITY TO MAKE A VIABLE UNIT.

Description:

Currently looking into the possibility of applying the Ball-Worm & Gear to the SynchroLite. No Propeller. Just a craft that is economical, light and could be built now. The craft could be flown with pilot on board and gas engine (50 - 60 hp), plus, tested with electric motor (10-25 hp) and electric power + control cables to the ground.

ref: Electric Motor:

Overrunning Clutch:

The overrunning clutch is to be located between the motor and the gearbox. The torque is ??? ft-lb.

This table was copied over and may not be applicable.

	Consider 2 Warner CSK 35 (Item 0568), Max. torque 207 ft-lb. Sprag. C/w brgs, 0.66 lbs.
	Consider Warner CSK 40, (Item 0741) Max. torque 384 ft-lb. Sprag. C/w brgs?, 1.10 lbs. This weighs more but it means less material in adjoining items.
	Consider 2 Marland-RINGSPANN R206 (Item 0524), Max. torque 195 ft-lb. No brgs. Keyway
	Consider Marland-RINGSPANN R208 (Item 0141), Max. torque 450 ft-lb. No brgs. Keyway
	http://www.stieber.de/products/gfkgb.html
	Look into the other ones mentioned on the line below

For additional information see: SynchroLite ~ Power Train (for 2-engines) - Overrunning Clutch Overrunning Clutch:

Housing:

An upper casting will contain the bearings for the mast and the attachment lug to the fuselage. The lower portion may consist of two halves, which might be identical except LH & RH, The left hand one has a plug where the input shaft is on the right hand one and this allows for a future PTO. ???

Lubrication:

Splash. How.

For additional Information see:

Another Idea: Worm & Ball-Wormgears: Move to its own page if it looks good.

Overview:

The balls recirculate within the wormgears; not within the worm.

Each 'tooth' in a gear has its own independent re-circulating ball track.

Last Revised: May 31, 2008