Snow blower repair

[Dave M7040]

At the other end of the shaft I am working on is a small sprocket that drives the auger chain. It has 3 bolt holes connecting the sprocket carrier to the shaft. They would work as shear bolts, if they break the sprocket will turn freely on the shaft. I am not planning on using them as shear bolts as it would be a very inconvenient place to install new bolts when packed with snow.

The sprocket location is where your shear bolts should be. Being closest to the overload when it occurs ensures that shock loads do not end up in your gearbox.

The turning sprocket and chain keep that area clear of snow. Many blower manufacturers suggest starting with fewer shear bolts than the 3 and only increasing the number if they break frequently..

Most blowers have the splined coupling welded to the sprocket shaft. It will be a much more durable connection than the pin one which as you saw on your blower lead to the coupling breaking.

Dave m7040

 

[Case 830]

I found a 19 spline coupling and had it machined to fit. The old shear pin hole in the shaft was filled in and redrilled for a tight fit. I decided to replace it as it was designed, i can always weld it in place later if i feel the need. 3 small bolts were put in place as shear pins on the chain end of the shaft. I didn’t like two shear bolts held the sprocket in this setup, without three the sprocket wasn’t inline with the chain. This is a very heavy blower and i am sure they will break before anything else.

The old coupling was also cut lengthwise on the non splined end, as if to allow the bolt to draw it tight. We didn’t do that, just a nice tight machined fit.

Thanks for the advice.I am glad to have it working and will be making improvements to it shortly.

 

[Dave M7040]

I found a 19 spline coupling and had it machined to fit. The old shear pin hole in the shaft was filled in and redrilled for a tight fit. I decided to replace it as it was designed, i can always weld it in place later if i feel the need. 3 small bolts were put in place as shear pins on the chain end of the shaft. I didn’t like two shear bolts held the sprocket in this setup, without three the sprocket wasn’t inline with the chain. This is a very heavy blower and i am sure they will break before anything else.

The old coupling was also cut lengthwise on the non splined end, as if to allow the bolt to draw it tight. We didn’t do that, just a nice tight machined fit.

Thanks for the advice.I am glad to have it working and will be making improvements to it shortly.

Thanks for the update.

With the legacy of blowers from manufacturers in that area of Ontario, you will have a tough product good for a long time.

Dave m7040

 

[radios1]

Th local smyth dealer told me to call smyth. Smyth said to call a dealer.

Turns out Lucknow also sells them. They said i can pick one up at the factory or call a dealer but they cant mail it. Ill double check the size with them before ordering.

Lucknow is in India. Lucknow - Wikipedia