Quote:
But I have said it works like the rear slave in Steve's description, the piston works one pad and the cylinder works the other, by what amounts to a hook, to double the effort from the same hydraulic pressure. In which case, the compression on the pad-disc-pad sandwich is (losses aside) exactly the same as the expansion caused between the piston and the back wall of the cylinder, i.e. twice the hydraulic pressure times the area of the piston. But because it works both pads, it takes as much energy to operate as the two piston fixed caliper set-up.
Graham
??? Difficult to follow but I am sure that contradicts what you said a few posts back.
You said .... See prev response about a single piston siding disc and single piston sliding caliper being different. But to add,
there's no connection from the force on the back wall of the cylinder and the second pad. The sliding caliper is like Steves description of the rear slave where the piston does half the work and the cylinder the other half.
I asked ..... If "there's no connection from the force on the back wall of the cylinder and the second pad." then
what is the cylinder pushing against?
You said ....... If you look at the diagram, you will see that the cylinder is in the caliper and that generates a bending moment on the
mounting at the top, which reacts equally to that to hold the caliper still - a spectacularly bad idea for a design, but it is just an example.
I asked .......... Yes I can see the cylinder is in the calliper and that there is a bending moment but what is the calliper attached to? One assumes at some point all the bits are connected together and the circle is completed otherwise there will be no force generated - i.e. what is effectively a sliding calliper or in your example a moving disc. You can't push against something and create a permanent (constant) force unless you are attached to it in some way otherwise it will simply be pushed away and in this case the disc will likely break as it runs out of ability to bend towards the second pad.
You said ....... But I have said it works like the rear slave in Steve's description, the piston works one pad and the cylinder works the other, by what amounts to a hook, to double the effort from the same hydraulic pressure. In which case, the compression on the pad-disc-pad sandwich is (losses aside) exactly the same as the expansion caused between the piston and the back wall of the cylinder, i.e. twice the hydraulic pressure times the area of the piston. But because it works both pads, it takes as much energy to operate as the two piston fixed caliper set-up.
So you have just said that
there is a connection between the back wall of the cylinder and the second pad via "the hook". So It is the same as a sliding calliper !!!!!!
Entertaining though it is I am going to leave it there until I can think of a practical way of actually demonstrating that the compression force is not the sum of the individual forces on the pads on either side of the disc.
Roger