----- Original Message ----- From: Horace Heffner <[email protected]> Date: Monday, June 29, 2009 3:24 pm Subject: Re: [Vo]:vortex balls!
> > On Jun 29, 2009, at 8:36 AM, Harry Veeder wrote: > > > > Yes the loop is closed, but I am working from the hypothesis that > > the bearings are accelerated by the magnetic field produced by the > > current flowing through the shaft. Therefore the bearings > > do not need to make electrical contact with the shaft, > > although they might need some start-up rotation. Note, > > my hypothesis is just a guess so I can't justify it on theoretical > > grounds using conventional physics. All I can say is that a > > "torque" is > > not required. This is becoming clearer to me as we talk about it. > > It there is no torque there will be no rotation. There is friction > that stops any rotation unless torque is maintained. If there is no > current there will be no torque. Yes if Newton's third law is the whole truth and nothing but the truth. > It there is a current through the shaft there is a circular B field > around the shaft, except in the vicinity of the brushes. A > circular B field, even if it magnetizes the balls, will produce no torque > upon the balls other than a torque that retards their rotation, unless > there is also a radial current through the balls. Remember I am making the shaft stationary so there are no brushes. (See my description above.) > It is easy to see, by symmetry, that a radial current through the > balls can not produce a net torque, because the circular B field is > > in the same direction at the bearings at both ends, but the current > > direction is into the shaft at one end and out at the other, thus > any > such torque must net to zero. The torque at one end of the shaft > exactly cancels the torque at the other end, provided both ends are > > symmetrical to each other. Assume the bearings are in the middle of a very long shaft so the relevant B field is circular. > Besides the symmetry argument, if you actually draw the > configuration > you can see that a circular B field will act on any radial current > through the balls to produce an axial force on the bearings, not a > torque on the bearings. > > If you look more carefully at what happens to the magnetic material > > in the ordinary Marino motor as it rotates, however, you can see > that > hysteresis (a delay in the de-magnetizing of the material) permits > magnetized material to rotate into place where the radial current > through it produces a torque that reinforces the direction of > rotation, which ever direction of rotation that might be. This is > all > laid out in diagrammatic form in Figs 3 and 4 of: > > http://www.mtaonline.net/~hheffner/HullMotor.pdf > > Further, the symmetry argument for the ordinary Marinov motor now > shows a reinforcing, not canceling, effect at both ends of the > shaft. This is because, when the current i is directed radially > into > the shaft, the magnetization direction of the material that rotates > > into place in the current stream is the opposite of the material at > > the other end of the shaft where the current is directed radially > out > of the shaft. The torque at both ends of the shaft is thus > reinforcing, and in the direction of the rotation, whichever > direction that might be. > > Best regards, > > Horace Heffner > http://www.mtaonline.net/~hheffner/ > > > > >
