Daily Life in China

 

 

Throwing distance.

The first thing to eliminate is throwing distance is not a simple function of chute height.  It's a function of an integrated design of a number of parts which function together. A designer has to consider distance but also throughput.  A snowblower could be designed to throw a mile but would suffer in clearing lots of snow.  It's a tradeoff.  A snowblower has to move along at a reasonable rate collecting snow and throwing it.  It has to do that in varying snow conditions.  You would be pleased when your snowblower threw light fluffy snow a great distance but unhappy when it fails to throw a crunchy pile very far.  A designer has to consider a 2 inch and 14 inch snowfall of varying types of snow.  That snow falls on the driveway and makes up the largest clearing area i.e. a fixed amount the height of the snowfall.  The end of the driveway always presents different conditions of a big pile which us usually much more compressed than what's on the driveway.  A compressed pile of end of the driveway (EOD) buildup does not throw anywhere near as far as six inches of snow that fell on the driveway. 

Designs have changed over the years improving distance and throughput but at times it seems a high marketing distance number overweighs the design. 

The parts making up the design are:

Intake housing shape How wide, tall, and the shape.  Designed for overall collection conditions.  You can't throw 2-3 inches of light snow very far.  A 22 inch wide machine will not collect much so not much to throw.  Two snowblowers with the same engines but one with a wide bucket will throw a light snow farther because it collects enough to throw.  The opposite happens when the very wide bucket collets too much to throw far.   
Auger diameter Generally 8 to 14 inches for collecting.  It determines just how much is pulled into the impeller.  Auger blades collect.  Impeller blades throw the snow up to the chute.
Auger shape Some are tilted more than others to sweep in snow.  Some have serrated blades which range from a slight wave to large pointed teeth sticking out from the blade.
Auger speed One of the big components of distance.  Speeds generally range from 100 to 140 RPM.  Early snowblowers from the 60's through 80's generally range around 100 to 110 RPM.  Approximatly at the end of the 70's companies boosted the RPM from 100 to 120 RPM.
Impeller diameter The impeller is a rotating disk with arms or vanes attached which catch and throw the snow up to the chute.  A larger diameter gets the speed up at the outer section of the diameter.  Impeller diameters generally are 10 to 14 inches in diameter.
Impeller shape Round generally with vanes attached. For vanes there are lots of different shapes.  Some are thin, others wide.  Some are thin at the center and widen at the furthest diameter.  Some are rounded, V shapped, rounded, and bent up at the ends.
Impeller speed Impeller speed is usually 10:1 with the auger speed.  Modern snowblowers are generally faster than pre-mid-80's machines.  Currently impellers usually run at 1200 to 1300 RPM. 
Impeller housing length The round barrel of the impeller area itself is short in some snowblowers and deeper in others.  It effects the collection and presentation of snow to the impeller.
Impeller housing exit shape. The impeller housing top section is an exit hole which leads into the chute.  Some are large and round, others are square.  The hole regulated the flow into the chute.
Chute shape Early chutes were wide U shapes.  Newer chutes are more rounded.  There is also a curve in the chute to direct the snow away from going straight up i.e. vertical.  The bend in the chute  determines the exit angle.  The length of the chute over which the curve happens determines if the snow will be slowed more than the same curve over a shorter distance.  A long easy angle lessens the resistance.  Some chutes taper from the base to the final exit point.
Hood shape The hood attached to the top of the chute can be pulled back out of the way to let the chute design control output flow.  Putting the hood over the chute out put stream directs the flow down at a lower angle relative to the amount of the hood pushed out over the stream.
Engine size A huge factor.in distance is the ability to muscle out the snow.  More beef gets more distance. But design is more important than a few horsepower.  I've used a 5.5hp machine that threw as well as an 8.  It could not collect as much snow at a time but for pure throwing distance it was a match for the bigger guns.  I've also used a 6.5hp machine that could stay with a 10hp and clear about the same amount doing that.  The difference was the 6.5 impeller was running at 1400 RPM.  

Clarance's impeller kit.  

The kit extends the length of the impeller vanes.  The vanes are attached to the impeller and are what collect and throws the snow.  The vane ends before the impeller housing so there is a gape there.  Some designs have more of a gap than others.  The kit lowers that distance to zero.  The hard rubbers tabs are added to the vane and extend to the impeller inside wall.  This is an obvious advantage as more snow is thrown.  It also adds a slight length to the rotating vane for a speed increase.  Most snow is gathered and thrown a little faster but the biggest consideration is that more snow is sent up into the impeller exit to the chute.  

The not so obvious disadvantage is dirt, sand, small stones, twigs will now rub against the impeller housing wall because there is no clearance anymore.  

Just about all reports I've heard about from people who have install the kit is the throwing distance was noticeably improved and they were happy with the result.  If you had a clear driveway and looking for a distance improvement then the kit would be a consideration.  If you have a gravel or loose stone driveway it's would not be a good idea.

Improvements, going for distance.

Addition of a tall chute can help on some designs. 

Smaller drive pulley on the engine crank shaft to get the impeller rotating at a higher RPM.  The auger gearbox will rotate faster so must also be considered.

Slick chute.  Some put silicon on the inside of the chute which would help for a very short time.  Some use wax or many other things to get the inside of the chute slipery.  A good thing would be a tough gloss paint like Rustoleum.  A slick plastic liner riveted inside the chute has been reported to have helped but it would have to be high quality to not scratch over time.  Painting and repainting every few years is probably the easiest way to go in getting a slick surface.

Bigger motor.  Most frames were predrilled at the factory for a range of motors.  For example Ariens sold many machines with a tractor base that could come in 6 through 11 horsepower.  MTD does the same thing.  If your motor is getting a bit tired it can probably be outfitted with the same or larger horsepower motor.