The Aermotor Windmill

In 1933 the Aermotor Company of Chicago redeveloped their 602 model windmill, and produced the 702 Model. This redevelopment incorporated such features as Replaceable Bearings, Screw-in Wheel Arms, and machine-cut Gears.

The 702 Model is now imported from Argentina, and is modified to suit the Australian towers. The high quality standards set by the original Aermotor are evident in this new windmill.

The Wheel, created to the latest design concepts, has exceptional strength. The round Wheel Arms are screwed directly into the hub, providing exceptional rigidity.

Sails of galvanized iron sheet have a scientifically-calculated curve that is designed to give a perfect rotational balance. The Aermotor pumps more water in lighter winds.

Replaceable Bearings of anti-friction white metal have a great resistance against wearing (greater than that provided by conventional bearing systems), and they are also very easy to change.

Double Gears, Pinions and thrust-type Ball-race balance the operating load to operate efficiently with minimum wear. In addition, Gears and Pitman Arms are designed to be easily changed. The optional "short stroke" allows for a greater pumping depth.

Lubrication ring - a complete but simple "lubrication system" that carries oil to the shafts, the Pitman Arms and the Guide Roller.

Rotational support by a thrust-type ball-race allows just the softest wind to activate the Tail and orientate the Windwheel towards the wind.

Band-type brake wraps around the Hub to stop wheel rotation, and simultaneously closes the Tail.

Limited maintenance requires a change of oil and a general inspection only once a year.

Vane Spring Adjustment allows the windmill to be tuned to the water demand.

Buffer Device softens the natural governing action of the Furling system.

Technical Specifications

MODEL WHEEL DIAMETER WEIGHT (Kg) PUMPING STROKE Gear Ratio R.P.M. a 20Km/h. STROKES per minute at 20Km/h.

LONG mm SHORT mm

6 ft 1.8 Mtrs 93 135 91 3.92:1 92 34

8 ft 2.4 Mtrs 153 190 147 3.29:1 132 28

10 ft 3.0 Mtrs 286 243 179 3.29:1 83 25

12 ft 3.6 Mtrs 470 285 208 3.50:1 71 21

Aermotor Windmill - Pumping Performance (based on 10 hours of wind per day)
Pump Size	Inches	2"	2.1/4"	2.1/2"	2.3/4"	3"	3.1/2"	4"
Pump Size	Millimetres	50.8mm	57.1mm	63.5mm	69.8mm	76.2mm	88.9mm	101.6mm
6ft (1.8 Mtr)	Feet	95	77	65	56	47
	Metres	29	23	20	17	14
	Avg. Galls per day	1080	1500	1870	2210	2670
	Avg. Litres per day	4900	6820	8500	10050	12140
8ft (2.4 Mtr)	Feet	140	112	94	80	68	50	39
	Metres	43	34	29	24	21	15	12
	Avg. Galls per day	1580	2170	2710	3210	3920	5330	6920
	Avg. Litres per day	7180	9870	12320	14600	17820	24230	31460
10ft (3.0 Mtr)	Feet	215	170	140	120	100	76	58
	Metres	66	52	43	37	30	23	18
	Avg. Galls per day	1580	2170	2710	3210	3920	5330	6920
	Avg. Litres per day	7180	9870	12320	14600	17820	24230	31460
12ft (3.6 Mtr)	Feet	320	250	210	180	155	115	86
	Metres	98	76	64	55	47	35	26
	Avg. Galls per day	1580	2170	2710	3210	3920	5330	6920
	Avg. Litres per day	7180	9870	12320	14600	17820	24230	31460

"Feet" & "Metres" is Total Dynamic Head - the height from the water source to the delivery tank including Friction Loss.
For rain fed dams add 4 Metres to the height to allow for seasonal losses.
Flow rates are shown in Gallons (Galls) and Litres per Day. If local wind conditions are light then divide by 10 (for litres per hour) and then multipy by the number of hours you expect the wind to blow.

Components

Main Casting Brake

Made of grey iron, also used for machines and engines with high requirements. This extraordinary solid casting guarantees a long lasting body. Moreover, a cover made of galvanized iron sheet closes the gear box hermetically so as to protect it from rain and dust.
Due to its great capability, the oil pan is able to contain a big amount of oil to assure a good permanent lubrication freno This brake is a friction band kind and works over the hub of the windwheel in order to avoid movements in the wheel when the windmill is turned off. It closes off with the windmill tail.

Buffer Device

It prevents strong shocks while releasing the windmill brake.

Hub & Shaft Thrust Bearing

Made of cast iron & special steel, it is positioned into long white metal bearings in the main gearbox. It includes a mechanism to assure permanent lubrication.
crapodina This pillow block, which functions as a journal bearing, consists of two rings mounted either side of small iron balls that rotate in a grooved track, giving the windmill more sensitivity. Just the softest breeze will cause the mill to face the wind.

GEARS Windwheel

Made of grey cast iron. Because of their high precision milling, the cogs have more surface contact. This characteristic guarantees longer lasting performance, and soft and silent running High level design and exceptional performance
typify these galvanized iron sails. Their curves - scientifically conceived - and the individual balance of each sail, result in a perfect rotational balance. The accurate slope of the sails provides greater efficiency to the Wheel. Since the Wheel Arms are screwed, they allow a perfect alignment of the wheel

Pitman

They are also made of grey cast iron. Their design makes it easier to change the stroke. The Long Stroke for normal pumping, the Short Stroke for higher heads or reduced flow.

Oil Ring Tail

It carries up abundant oil to the Crosshead Shaft, Pumprod and Guide Roller. This ring is a very simple "automatic lubrication system". It replaces oil pumps, springs and all the mechanisms that not only complicate windmills, but which are also likely to wear out. You only need to change the oil once a year.
Made of galvanized iron sheet, with a strengthening vane throughout. The assembly, supported by the Tailbone, assures maximum rigidity. The whole mechanism of the tail is pivoted on a strong supporting axis. The tail dimensions and weight are proportional to the wheel in order to achieve an exact balance. This makes the windmill react easily to the intensity and direction of the wind.