Mini traction engine and baker fan

Mini traction engine and baker fan

Googling I've read that "these were designed by a Mr. A.D. Baker to test steam engines as they left the factory. A Baker Fan is a simple air-resistance device used run off an engine via a belt and the faster its turned, the harder it is to turn and puts a load on the engine"

Very nice little unit, both engine and fan. The full sized Baker Fan would have been something to behold in action.

Great demonstration

and a nice job on that fan.

MichaelG.

.

Just found some good photos of a full-size one:

http://www.troyewelch.com/ksw/KSW%20baker%20fan%20steamup.html

Edited By Michael Gilligan on 10/03/2021 09:10:22

Unfortunately I can't see the photo I assume is in your second post, but the Baker Fan is an interesting and unusual adjunct to the engine.

Baker had not been all that original though, even if the application was novel.

A fan as a test-load uses the principle of the Fly, developed by the earliest clock-makers to control the rate of the striking train. The world's oldest working clock, displayed in Salisbury Cathedral I think, is so fitted. (Clocks of that era had no dials, and were mainly for announcing the times of church services.). In later centuries the Fly, driven by a reversed worm, became used as the speed regulator in musical-box movements.

A common alternative for testing engines was the Rope-Brake Dynamometer, which uses a spring-balance or calibrated weights to measures the torque while applying the load. A subsequent development was a hydraulic version - a torque-convertor with its output connected to a spring balance.

Nigel,

It would appear that the Baker Fan was intended as a Dummy Load [presumably for running-in engines] rather than as a Test Dynamometer: **LINK**

https://www.farmcollector.com/steam-traction/the-baker-fan

This ^^^ seems to make good sense

MichaelG.

Aero engines were loaded by means of a "club prop, a small diameter propellor, presumably of coarse pitch, to absorb the power.

If it behaved like a marine propellor, the power absorbed as the speed increased would not be linear, but to the power of about 2.8.

Howard

Some years back at a steam rally I saw a sream engine connected to a large drum which in turn had a brake band around it which could be adjusted to alter the load, I never noticed if there was any sort of metering device.

h

Meet Mr Baker : **LINK**

https://saudervillage.org/field-trips/school-field-trips/curriculum-resources/people-behind-the-buildings/a-d-baker

MichaelG.

...

... and, going off-topic, his patented rotary engine

https://worldwide.espacenet.com/patent/search?q=pn%3DUS440125A

Edited By Michael Gilligan on 10/03/2021 14:18:46

A lot of Technical Colleges had, by our standards, OLD single cylinder engines in their Heat Engine labs.. Load was applied by a rope around the circumference of a hollow "Flywheel" drum, with the other end connected to a spring balance.. The energy was dissipated as heat, which boiled water poured into the hollow drum. This device was usually referred to as a Prony brake.

The single cylinder Blackstone engine at The WaterWorks Museum came from a Technical College and has this form of drum on the opposite end of the crankshaft from the Flywheel proper. It also has a Dobbie McInnes indicator and the linkage to enable it to be connected to crankshaft to take indicator diagrams. The two systems would have enabled the engine to be compared on the basis of Brake Horse Power and Indicated Horse Power, to reflect pumping and frictional losses.

This form of brake was only suitable for engines of low output and speed. For high speed and power engines a hydraulic dynamometer of the Heenan and Froude type or an eddy current dynamometer would be needed.

Eddy current dynos, often gave closer control of load that the hydraulic type.

H&F DPX dynos were designed to run in one direction only, the DPY models having two rotors of opposite hand could be run in either direction, and so could be used to test marine engines with gearboxes attached.

In each case the power was dissipated by heating the water which passed to cooling towers..

Howard

Tractor dyno was a large alternator on the shaft. By switching in various heating elements and reading the power output in electrical units gave the load on watts- 746w= 1 Hp. It was a giant fan heater ! Noel.

We used to have problems with folk claiming that a PTO power was way down on the stated engine power.

They ignored transmission losses.

On one particular model of tractor, at our insistence, one engine was PTO tested against a large enough number of transmissions to be statistically significant . Losses varied between 5 bhp and 32 bhp!

Another major customer complained of low power outputs.

Their tests were carried out as stall down tests, at dealerships all across Europe, using unknown fuels, and under unknown ambient conditions..

When I asked what was the range of transmission losses, no one seemed to have considered them. Subsequent work showed the transmission losses to have a wide spread!

To test generators for welding sets, we had to buy a special load bank which was quite different from those used for conventional gensets. Dissipating 40Kw at 20 volts, DC or AC, called for a quite different set up from 40 Kw at 450 volts three phase.

Howard