Silent chains have been used for years on the camshaft drives of many popular US V8's like the Small and Big Block Chevy and the Ford V8's. I think the Dodge V8s also used a similar silent timing chain.
I talked to a Gate Belt engineer years ago about running a Gates timing type belt (HTD at the time) under water and he said the belt would have a problem with that and eventually fail. However he said the same belt would have no issues running in oil which really surprised me! He said they were designed to run in oily, greasy environments and as such running in oil would not likely be a problem. Dave On 8/10/2015 9:46 AM, Gene Heskett wrote: > On Monday 10 August 2015 08:34:53 andy pugh wrote: > >> I recently replaced the cam-chain on my motorcycle. >> >> I am not sure I needed to, the new one I bought wasn't very much >> shorter than the old one. >> Examining the drive, it appears to be zero-backlash and to work with >> normal involute-toothed gears. >> In fact, it seems like an ideal drive for a CNC axis. It should be >> stiffer than a toothed belt, much stronger and (according to >> http://www.promsnab.info/catalogues/bosch/tooth%20chains/inverted%20to >> oth%20chains.pdf quieter too). They are also known as "silent chains" >> so there might be some truth in this. >> >> The requirements of a camtrain drive are very similar to those of a >> CNC axis, and it is interesting to note that the other main-player in >> camtrain drives is the toothed belt. >> >> An inverted tooth chain can run in oil. There are belt-in-oil camtrain >> drives on some engines, but I think that they are specially >> formulated. >> >> The cam-chain I removed had done 100,000 miles, most of it at 5000 rpm >> or more. (and up to 14,000 rpm) > The camchain in the last Honda I had, a CB350F was still in good shape at > nearly 90 thousand miles when I sold it to the next owner for more than > I had paid for it with a bad alternator stator and the drive chain and > sprockets all run out. Previous owner never knew what a can of chain > lube was for. > > A sprung shoe tensioner kept it from chewing on the rest of the bits & > pieces. On that small an engine, it spent lots of time north of 9 > grand, up to 12 when asking for max giddyup. I used it for a chair car > as the other rig was a 28' Pace Arrow, putting 33 thou of those miles on > it in 14 months in and around Janesville/Susanville CA. > > If one had the breaker tools to make it the length needed, it probably > would have been long enough to do all 3 axis's on a regular T.T. mill > similar to this GO704 I am working on now. The direct drive motors > hanging out do make it a space hog, X in particular. > > Cheers, Gene Heskett --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
