Manufacturing method for a brushless direct current electric motor
A method for manufacturing a brushless motor includes providing a sleeve having a plurality of deformation zones spaced around a circumference of the sleeve, and a plurality of counterbores each having a rounded bottom and extending over the length of an inner surface of the sleeve such that only one of said plurality of counterbores is disposed between adjacent ones of said plurality of deformation zones. Metal rings are stacked to form a stator having a plurality of partitions each having a flat end face for engaging the inner surface of the sleeve. Copper wires are wound around the partitions, and the stack is mounted in the sleeve so that the end faces of the plurality of partitions are positioned adjacent the deformation zones. A rotor is provided, and is inserted into an inner cavity of the stator.
1 . A method for manufacturing a brushless motor, the method comprising steps of:
providing a sleeve having a plurality of deformation zones spaced around a circumference of the sleeve, and a plurality of counterbores each having a rounded bottom and extending over the length of an inner surface of the sleeve, wherein only one of said plurality of counterbores is disposed between adjacent ones of said plurality of deformation zones;
stacking a plurality of metal rings to form a stator having a plurality of partitions extending radially outwardly from a cylindrical main body, each of the plurality of partitions including a flat end face for engaging the inner surface of the sleeve, the stator delimiting open volumes for receiving coils;
winding copper wires around the partitions on the stack;
mounting the stack in the sleeve, wherein the mounting of the stack further comprises positioning said plurality of deformation zones such that said end faces of the plurality of partitions are positioned adjacent associated ones of said plurality of deformation zones;
providing a rotor; and
inserting the rotor into an inner cavity of the stator.
2 . The method of claim 1 , further comprising grinding external and internal diameters of the stator.
3 . The method of claim 1 , further comprising forming the sleeve by stacking a plurality of rings.
4 . The method of claim 1 , further comprising forming the rotor from at least one permanent magnet disposed on an outer face of the rotor.
5 . The method of claim 4 , wherein the forming of the rotor comprises forming the permanent magnet so that the permanent magnet extends over an entire length of the rotor.
6 . The method of claim 1 , wherein the mounting of the stack comprises positioning the sleeve to surround an active part of the stator, wherein the forming step comprises providing the active part of the stator as a portion of the stator having said winding of copper wires.
7 . The method of claim 1 , further comprising forming a thinned zone in a main body of said stator.
8 . The method of claim 7 , said forming the thinned zone comprises forming a groove in said main body of said stator.
9 . The method of claim 1 , wherein said stacking the plurality of metal rings further comprises forming the plurality of partitions to extend radially outwardly from a cylindrical main body of said stator so that said partitions together define at least two volumes for receiving at least three coils for generating a magnetic field.
10 . The method of claim 9 , wherein said stacking the plurality of metal rings further comprises forming the plurality of partitions so that each volume is closed by a second wall formed by a portion of the main body connecting the partitions so that said second wall comprises a magnetic restriction zone formed by at least one wall portion made of at least one slightly magnetic or non-magnetic material.
11 . The method of claim 9 , wherein said stacking the plurality of metal rings further comprises forming the plurality of partitions so that each volume is closed by a second wall formed by a portion of the main body connecting the partitions so that the second wall comprises a magnetic restriction zone formed by at least one zone thinner than said second wall.
12 . The method of claim 11 , wherein said forming the plurality of partitions comprises forming said magnetic restriction zone on an inner face of said second wall oriented toward said rotor.
13 . The method of claim 11 , wherein said forming the plurality of partitions further comprises forming the thinner zone as a groove.
14 . The method of claim 11 , wherein the thinner zone is formed by a groove on an inner face of said main body of said stator and a grooving positioned on an outer face of said main body of said stator.