Abstract A method of manufacture of a permanent-magnetized rotor for a small multipolar synchronous motor from a rectangular tape made of a flexible plastomagnetic material comprising an organic binder loaded with magnetic powder, wherein said flexible tape has a rectangular or square cross-section and is cut to suitable dimensions and then shaped as a ring with a trapezoidal crosssection through contiguous winding on a cylindrical mandrel with a suitable diameter and is subjected to a curing operation designed to impart to it a predetermined stiffness while maintaining in it a slight expansibility, due to the controlled curing of the binder and then after the concentric introduction of the ring and of an axis in a mold with a cylindrical wall, the axis and the ring are made integral through injection of a thermoplastic or thermosetting material or of a metal having a low melting point whose pressure tends to apply the ring onto said cylindrical wall of the mold the internal diameter of which corresponds precisely to the external diameter of the finished rotor.
A method of manufacture of a permanent-magnetized rotor for a small multipolar synchronous motor for a rectangular tape made of a flexible plastomagnetic material comprising an organic binder loaded with magnetic powder, comprising the steps of; cutting said flexible tape to a suitable length; winding the length of tape onto a cylindrical mandrel to shape said length into the form of a ring having a trapezoidal cross-section; performing a controlled curing operation on the organic binder of said ring such that said ring has a predetermined stiffness but retains the ability to slightly expand; introducing said ring and a shaft into a mold having a cylindrical wall, said wall, said ring and said shaft being in concentric relationship, said wall having an internal diameter which precisely corresponds to the desired external diameter of the finished rotor; injecting a molding material into the mold thereby expanding said ring against said wall; soldifying said molding material to thereby form an integral structure of said shaft, said molding material and said ring.
Claim 2
Independent Claim
169 words
A method of manufacture of a permanent-magnetized rotor for a small multipolar synchronous motor for a rectangular tape made of a flexible plastomagnetic material comprising an organic binder loaded with magnetic powder, comprising the steps of; cutting said flexible tape to a suitable length; winding the length of tape onto a cylindrical mandrel to shape said length into the form of a ring having a trapezoidal cross-section; performing a controlled curing operation on the organic binder of said ring such that said ring has a predetermined stiffness but retains the ability to slightly expand; introducing said ring and a shaft into a mold having a cylindrical wall, said wall, said ring and said shaft being in concentric relationship, said wall having an internal diameter which precisely corresponds to the desired external diameter of the finished rotor; injecting a molding material into the mold thereby expanding said ring against said wall; soldifying said molding material to thereby form an integral structure of said shaft, said molding material and said ring.