How to / DIY > Generators

Type of Rubber for LoveJoy, ST -> ChangFa

<< < (2/2)

mjn:
You can probably do just fine with a straight edge along both halves of the lovejoy.   Getting the horizontal axis lined up is fairly easy, you just push the ST head back and forth until both shafts appear to be perfectly straight.

The vertical alignment is trickier.  In my case, I needed to add a series of shims under the feet on the ST to bring it to the same level as the Changfa.  As long as you are not in a hurry (as I was) you will be just fine.

I'm glad you enjoyed my website.  In my spare time this summer, I've been rebuilding an old shed to become the "Casa de Changfa".  I'll need to get a trench dug for the power cables and something better than dirt for a floor.  Hopefully I get that done before it starts snowing.

europachris:

--- Quote from: mjn on September 29, 2006, 03:04:11 AM ---My Changfa 195 is coupled to the ST head with a Lovejoy L-150 with a "buna" spider.  Given the sort of hammering that a single cylinder diesel engine produces, I think the softer rubber would be better than the harder plastic.

When I was putting my generator together, I made a quick measurement to determine the shaft heights.  I was so eager to start producing electricity, that I did not put a dial indicator on the shafts to determine how far off I was.  My eyeball said "looks close enough".  It turns out the axial alignment was off by about .060".  I ran about 100 hours before I caught on.  When I pulled it apart, there was no visible wear on the spider even with rubbing back and forth .060 on every revolution. 



--- End quote ---


I found temperature is an even bigger issue.  I had a little Honda gas motor coupled with Lovejoy direct to my 3600 rpm head for a while, and the engine heat would conduct along the crankshaft, heat up the coupler, and soften the rubber spider enough that it would just fall apart.  Also compounding the issue is the Honda didn't have a lot of flywheel, so it pounded the spider pretty good.

Chris

dkwflight:
Hi A bigger issue is the size of the unit. I believe the Horsepower ratings of this type of joint is for electric motors. To get any kind of life from them you should order the largest one that will fit.
Dennis

europachris:

--- Quote from: dkwflight on September 30, 2006, 12:56:12 AM ---Hi A bigger issue is the size of the unit. I believe the Horsepower ratings of this type of joint is for electric motors. To get any kind of life from them you should order the largest one that will fit.
Dennis

--- End quote ---

Correct.  Lovejoy publishes a selection table that covers the type of driver (electric motor, single or multiple cylinder engine, etc) and calculates the size of coupler required.  Definitely pick the biggest one that will fit.

Chris

mjn:
I have the lovejoy specs in an old MSC catalog:

seriesrated HP
at 1750 rpmmax rpmbuna-nurethanehytrelL0955.59000194 inch-lbs291 inch-lbs561 inch-lbsL10011.970004176261134L11023500079211882268L150355000124018603708L190495000172625924680
Spider types:
    Buna-N -- oil resistant, temperature range -40 - 212F.  1º angular misalignment
    Urethane -- greater torque capacity, temperature range -30 - 160F. 1º angular misalignment
    Hytrel -- high torque and high temperature applications (-60 - 250F)  .5º angular misalignment


An ST 7.5 head has a 38mm shaft.  My catalog lists the L110 as the only series available with that shaft size.
I am using an L150 that I bored out to 38mm and I'm quite happy with it so far.

I have never found the coupling to be more than barely warm even after extended operation. The flywheel adapter only touches the flywheel in 3 places, so I suspect it tends to isolate the coupler from any engine heat.

Navigation

[0] Message Index

[*] Previous page