METHOD FOR MAKING ARMATURE-COMMUTATOR ASSEMBLY HAVING ARMATURE WINDING OF VERY SMALL DIAMETER

• US 3,781,981 A
• Filed: 02/28/1972
• Issued: 01/01/1974
• Est. Priority Date: 02/28/1972
• Status: Expired due to Term

• Current Assignee: Tatuo Miura, Toshiro Kaneko
• Original Assignee: Tatuo Miura, Toshiro Kaneko
• Inventors: Miura, Tatuo, Kaneko, Toshiro
• Primary Examiner(s): Herbst, Richard J.
• Assistant Examiner(s): Hall, Carl E.
• Application Number:
  US05/229,991
• Time in Patent Office: 673 Days
• Field of Search: 29/597,598,25CM,25C,78,87 310/234
• US Class Current: 29/597
• CPC Class Codes: H01R 39/32 Connections of conductor to commutator segment
• CPC Class Codes: Y10T 29/49011 Commutator or slip ring assembly
• CPC Class Codes: Y10T 29/49012 Rotor
• CPC Class Codes: Y10T 29/53157 Means to stake wire to commutator or armature

Abstract

Apparatus and method for making an armature-commutator assembly having an armature winding wire of very small diameter comprising forming a plurality of wire-engaging fingers on the commutator, engaging a plurality of insulated conductors led out of the armature winding with the fingers, applying equal pressure simultaneously to all the engaging portions by a plurality of electrode bars whose number is equal to the number of the fingers and which have at their engaging end a recess portion of a depth which is approximately equal to the diameter of the comductor, and while continuing to apply that pressure, supplying to the electrode bars either equal valued currents simultaneously, or successively reduced currents sequentially for electrically connecting the fingers with the conductors.

Claims

1. A method of making an armature-commutator assembly having an armature winding of insulated wire of very small diameter which assembly is formed by fitting an iron core having an armature winding of said very small diameter wire wound therearound and a commutator on an armature shaft and then providing electrical connection between said armature winding and said commutator, said method comprising the steps of forming a plurality of wire-engaging fingers on said commutator, engaging a plurality of insulated wire conductors led out of said armature winding with engaging portions of said fingers, deforming the engaged conductors by applying substantially equal pressure simultaneously to all the engaging portions by a plurality of electrode bars whose number is equal to the number of said fingers, and which have at their engaging end a recess portion of a depth which is approximately equal to the diameter of said conductor, wherein each said recess portion is superposed over a respective one of said conductors and by virtue of the recess portions controlled deformation of said conductors occurs, and supplying a substantially uniformly commutator heating controlled current to said electrode bars for electrically connecting said fingers with said conductors.

2. A method according to claim 1, which comprises a further step of pre-forming a low-melting metal film on the surface of said wire-engaging fingers provided on said commutator so as to ensure a positive electrical connection between said fingers and said conductors.

3. A method of making an armature-commutator assembly comprising the steps of:

forming a plurality of conductor-engaging fingers on said commutator, engaging a plurality of insulated conductors led out of an armature winding with engaging portions of said fingers formed by bending end portions of said fingers over the commutator, applying pressure to said engaging portions simultaneously by electrode bars corresponding thereto, and supplying successively decreasing controlled currents to said electrode bars sequentially, while maintaining said applied pressure.

4. A method according to claim 3, including limiting said pressure as it is effectively applied to the respective conductors engaged by said fingers by using said electrode bars formed at their finger engaging end with a recess superposing the conductor and having a depth approximately equal to the diameter of said conductor and having a length smaller than the length of said fingers.

5. A method according to claim 3, wherein the surfaces of said fingers are coated with a low-melting metal prior to engaging said fingers with said conductors.

6. A method of making an armature-commutator assembly comprising the steps of:

forming a plurality of conductor-engaging fingers on said commutator, engaging a plurality of insulated conductors led out of an armature winding with engaging portions of said fingers formed by bending end portions of said fingers over the commutator, applying pressure to said engaging portions simultaneously by electrode bars corresponding thereto wherein said pressure is limited as it is effectively applied to the respective conductors engaged by said engaging portions of said fingers by using said electrode bars formed at their finger engaging end with a recess, each of which superposes a respective conductor and has a depth approximately equal to the diameter of said conductors and has a length sMaller than the length of said fingers whereby deformation of the conductors is controlled, and supplying said electrode bars simultaneously with currents of the same value, while maintaining said applied pressure.

7. A method of making an armature-commutator assembly according to claim 6, wherein the surfaces of said fingers are coated with a low-melting metal prior to engaging said fingers with said conductors.

8. A method of making an armature-commutator assembly having an armature winding of insulated wire of very small diameter, comprising the steps of:

forming a plurality of conductor-engaging fingers on said commutator, coating the surfaces of said fingers with tin, engaging a plurality of insulated conductors led out of said armature winding with engaging portions of said fingers formed by bending end portions of said fingers over the commutator, applying equal pressure simultaneously to all the engaging portions by electrode bars respectively corresponding thereto to deform said conductors, limiting the applied pressure as it is effectively applied to said conductors by using said electrode bars formed at the engaging end thereof with a recess superposing said conductor and having a depth approximately equal to the diameter of said conductor whereby deformation of said conductors is controlled, and concurrently supplying equal valued currents to said electrode bars simultaneously for fusing said fingers with said conductors.

9. A method of making an armature-commutator assembly comprising the steps of:

connecting a plurality of insulated conductors extending from an armature winding to a respective plurality of projecting commutator fingers having portions bent over the conductors and commutator to hold the conductors between the respective fingers and commutator, and fusion welding said fingers and conductors by simultaneously pressing each of said fingers onto its insulated conductor and against said commutator with controlled limited conductor deformation and concurrently passing current through each pressed finger and the commutator, wherein said finger pressing is effected and effectively limited as to its effect on deformation of the conductors by respective electrode bars each of which has a land contacting the end of the finger and which has an adjacent recess having a depth approximately equal to the diameter of the respective conductor for contacting the respective finger thereover and having a length which is less than the length of said fingers, said pressing being continued until the electrode lands are spaced from said commutator a distance approximating the thickness of said fingers, characterized by the magnitude of the pressure effecting said pressing and the magnitude of said current for each pressed finger being sufficiently large to completely thermally destroy and peel off the insulation from the conductor under each pressed finger and to cause lateral flow of the peeled off insulation so as to preclude the presence of insulation in the interface of each joined conductor and finger, said pressure magnitude being less at each finger than that which reduces the sectional shape of the conductor so much as to reduce significantly the strength of the condocutor at its connection to the respective finger, and said current magnitude at each finger being less than that which causes the temperature in the commutator at that finger to be significantly higher than at other fingers during the said fusion welding of all the fingers and conductors and less than that which causes complete melting of the respective conductor.

10. A method of making an armature-commutator assembly comprising the steps of:

connecting a plurality of insulated conductors extending from an armature winding to a respective plurality of projecting commutator fingers having portions bent over the conductors and commutator to hold the conductors between the respective fingers and commutator, and fusIon welding said fingers and conductors by simultaneously pressing each of said fingers onto its insulated conductor and against said commutator with controlled limited conductor deformation and concurrently passing current through each pressed finger and the commutator, characterized by the magnitude of the pressure effecting said pressing and the magnitude of said current for each pressed finger being sufficiently larger to completely thermally destroy and peel off the insulation from the conductor under each pressed finger and to cause lateral flow of the peeled off insulation so as to preclude the presence of insulation in the interface of each joined conductor and finger, said pressure magnitude being less at each finger than that which reduces the sectional shape of the conductor so much as to reduce significantly the strength of the conductor at its connection to the respective finger, and said current magnitude at each finger being less than that which causes the temperature in the commutator at that finger to significantly higher than at other fingers during the said fusion welding of all the fingers and conductors and less than that which causes complete melting of the respective conductor, wherein the said passing of current through said fingers is effected sequentially to the fingers and wherein at least one of the later fingers in the sequence receives a said current of lesser value than a finger earlier in the sequence to prevent commutator temperature rise.

11. A method as in claim 9 wherein each said finger is coated with a low-melting metal before the respective insulated conductor is connected thereto for providing a more firm fusion welded bond between the respective fingers and conductors so as to make the electrical connection therebetween more stable against oxidization, sulfurization and other corrosion.

12. A method of making an armature-commutator assembly comprising the steps of:

forming a plurality of conductor-engaging fingers on said commutator, engaging a plurality of insulated conductors led out of an armature winding with engaging portions of said fingers formed by bending end portions of said fingers over the commutator, deforming the engaged conductors by applying substantially equal pressure to said engaged portions simultaneously by electrode bars corresponding thereto, limiting the amount of said conductor deformation while said pressure is applied by using electrode bars formed with recesses, each having a depth approximately equal to the diameter of the conductors and each recess superposing a respective conductor, and supplying currents to said electrode bars while maintaining said applied pressure.

13. A method of making an armature-commutator assembly comprising the steps of:

forming a plurality of conductor-engaging fingers on said commutator, coating the surface of said fingers with low-melting metal, engaging a plurality of insulated conductors led out of said armature winding with said fingers bent over the circumferential periphery of said commutator and said conductors to effect a finger end portion extending beyond each said conductor, limitedly deforming said engaged conductors by applying pressure simultaneously to all the fingers by electrode bars formed at the engaging end thereof with a land contacting a said finger end portion and with a recess having a depth approximately equal to the diameter of the respective conductor for contacting the respective finger thereover, and supplying successively decreasing controlled currents to said electrode bars sequentially for fusing said fingers with said conductors, while maintaining said applied pressure, to thermally destroy and peel off the conductor insulation from under the fingers and cause lateral flow thereof and to flatten said finger end portions against said commutator.

14. A method of making an armature-commutator assembly comprising the steps of:

forming a plurality of conductor-eNgaging fingers on said commutator, coating the surface of said fingers with low-melting metal, engaging a plurality of insulated conductors led out of said armature winding with said fingers bent over the circumferential periphery of said commutator and said conductors to effect a finger end portion extending beyond each said conductor, limitedly deforming the engaged conductors by applying pressure simultaneously to all the fingers by electrode bars formed at the engaging end thereof with a land contacting a said finger end portion and with a recess having a depth approximately equal to the diameter of the respective conductor for contacting the respective finger thereover with said recess superposed over said respective conductor, and supplying equal valued currents to said electrode bars simultaneously for fusing said fingers with said conductors, while maintaining said applied pressure, to thermally destroy and peel off the conductor insulation from under the fingers and cause lateral flow thereof and flatten said finger end portions against said commutator.

15. A method of making an armature-commutator assembly having an armature winding of insulated wire of very small diameter, comprising the steps of:

forming a plurality of conductor-engaging fingers on said commutator, coating the surface of said fingers with tin, engaging a plurality of insulated conductors led out of said armature winding with engaging portions of said fingers, limitedly deforming said engaged conductors by applying pressure simultaneously to all the engaging portions by electrode bars respectively corresponding thereto, each of said electrode bars being formed at the engaging end thereof with a recess having a depth approximately equal to the diameter of said conductor, and supplying successively decreasing currents to said electrode bars sequentially for fusing said fingers with said conductors, while maintaining said applied pressure.