I joined the Ruislip Lido Railway Society over 10 years ago and have worked in the Nissen Hut that houses our workshop and loco storage ever since. We have all sorts of tools and machines to play with, but sometimes lack of fully-skilled staff has meant delays to some projects.
Every year we do a C exam on all our rolling stock and some faults were common, but over the years, we have made small changes to overcome these faults so that the stock has been relatively fault-free for a goodly period.
HOWEVER....reports come back from the operating staff, every once in a while, about rumbling axle bearings. These are a self-aligning roller bearing housed in a block bolted to the bogie frame which sits below the carriage. Obviously, once the axle is set into position across the bogie and the blocks are tightened, they will assume a position and the self-alignment feature is no longer required.
What we have noticed over the years, is that the bearing inner race is turning relative to the axle (or is it vice versa?). In previous times, the bearings have been a push fit with grub-screw used to locate the bearing onto the axle. As we worked through our problem units, we discovered that the grub-screw were quite ineffective and were being dragged round the axle shafts, causing a gouge on the axle.
We have instigated a slightly tighter fit for the bearings by means of fitting new bearings to a turned-down axle shaft. We now use a puller to fit the bearings onto the axle shafts and we are obtaining a much improved situation so far.
SO....Why does it happen? Nobody has come up with a complete answer, but I have a theory in that the tightness of our main station's curve is loading the bearings in a lateral direction and basically seizing them, or placing so much load that the inner race is trying to stop, while the axle is still rotating.
At present, I have no pictures to illustrate the problem and how we are seeking to cure it, but in the meantime, I will post a map and a photo of our "toys".
Every year we do a C exam on all our rolling stock and some faults were common, but over the years, we have made small changes to overcome these faults so that the stock has been relatively fault-free for a goodly period.
HOWEVER....reports come back from the operating staff, every once in a while, about rumbling axle bearings. These are a self-aligning roller bearing housed in a block bolted to the bogie frame which sits below the carriage. Obviously, once the axle is set into position across the bogie and the blocks are tightened, they will assume a position and the self-alignment feature is no longer required.
What we have noticed over the years, is that the bearing inner race is turning relative to the axle (or is it vice versa?). In previous times, the bearings have been a push fit with grub-screw used to locate the bearing onto the axle. As we worked through our problem units, we discovered that the grub-screw were quite ineffective and were being dragged round the axle shafts, causing a gouge on the axle.
We have instigated a slightly tighter fit for the bearings by means of fitting new bearings to a turned-down axle shaft. We now use a puller to fit the bearings onto the axle shafts and we are obtaining a much improved situation so far.
SO....Why does it happen? Nobody has come up with a complete answer, but I have a theory in that the tightness of our main station's curve is loading the bearings in a lateral direction and basically seizing them, or placing so much load that the inner race is trying to stop, while the axle is still rotating.
At present, I have no pictures to illustrate the problem and how we are seeking to cure it, but in the meantime, I will post a map and a photo of our "toys".
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