Varistor disk assembly

A varistor disk assembly for mounting to a base of a commutator mounted on a motor shaft, comprising:

• a non-conductive retaining ring, said retaining ring having an axial bore therethrough dimensioned to provide a friction fit with the motor shaft, a proximal end for orientation facing towards the commutator base, and a distal end for orientation facing away from the commutator base;
• a conductive member configured to receive said shaft therethrough for placement at the commutator base;
• a varistor disk configured to receive said shaft therethrough for interposition between said conductive member and said proximal end of said retaining ring;
• and
• a tolerance absorbing member for interposition between said varistor disk and said retaining ring.

A varistor disk assembly for mounting to a base of a commutator mounted on a motor shaft, comprising:

• a non-conductive retaining ring, said retaining ring having an axial bore therethrough dimensioned to provide a friction fit with the motor shaft, a proximal end for orientation facing towards the commutator base, and a distal end for orientation facing away from the commutator base;
• a conductive member configured to receive said shaft therethrough for placement at the commutator base, wherein said conductive member comprises an extruded rubber ring provided at its outer periphery with a plurality of spaced grooves and a layer of conductive metal extruded in said grooves;
• and
• a varistor disk configured to receive said shaft therethrough for interposition between said conductive member and said proximal end of said retaining ring.

A varistor disk assembly for mounting to a base of a commutator mounted on a motor shaft, comprising:

• a non-conductive retaining ring, said retaining ring having an axial bore therethrough dimensioned to provide a friction fit with the motor shaft, a proximal end for orientation facing towards the commutator base, and a distal end for orientation facing away from the commutator base, wherein said proximal end of said retaining ring is necked in, said distal end of said retaining ring has a periphery formed with at least one planar side, and said proximal end of said retaining ring has a periphery formed with a planar side;
• a conductive member configured to receive said shaft therethrough for placement at the commutator base;
• and
• a varistor disk configured to receive said shaft therethrough for interposition between said conductive member and said proximal end of said retaining ring;
• wherein said conductive member and said varistor disk are generally annular in shape and have inner diameters dimensioned to enable them to pass freely over the motor shaft and to receive said proximal end of said retaining ring, and the inner diameter of said varistor disk is provided with a planar side complementary to said planar side of said proximal end of said retaining ring, said planar side of said retaining ring being oriented to result in proper alignment of said varistor disk with said commutator.

A motor armature comprising:

• a motor shaft;
• a commutator concentrically mounted on said motor shaft, said commutator including a base and a plurality of peripheral segments;
• an annular conductive member encircling said motor shaft and positioned at said commutator base, said conductive member being compressible and having a thickness;
• an annular varistor disk encircling said motor shaft and positioned adjacent to said conductive member, said conductive member being constructed to conduct current through its thickness from the commutator base to said varistor disk but not to conduct current between adjacent commutator segments;
• and
• a non-conductive retaining ring, said retaining ring having an axial bore therethrough dimensioned to provide a friction fit with the motor shaft, a proximal end oriented facing towards said commutator base, and a distal end oriented facing away from said commutator base.

A motor armature comprising:

• a motor shaft;
• a commutator concentrically mounted on said motor shaft, said commutator including a base;
• an annular conductive member encircling said motor shaft and positioned at said commutator base;
• an annular varistor disk encircling said motor shaft and positioned adjacent to said conductive member;
• a non-conductive retaining ring, said retaining ring having an axial bore therethrough dimensioned to provide a friction fit with the motor shaft, a proximal end oriented facing towards said commutator base, and a distal end oriented facing away from said commutator base;
• and
• a tolerance absorbing member interposed between said varistor disk and said retaining ring.

A motor armature comprising:

• a motor shaft;
• a commutator concentrically mounted on said motor shaft, said commutator including a base;
• an annular conductive member encircling said motor shaft and positioned at said commutator base, wherein said conductive member comprises an extruded rubber ring provided at its outer periphery with a plurality of spaced grooves and a layer of conductive metal extruded in said grooves;
• an annular varistor disk encircling said motor shaft and positioned adjacent to said conductive member;
• and
• a non-conductive retaining ring, said retaining ring having an axial bore therethrough dimensioned to provide a friction fit with the motor shaft, a proximal end oriented facing towards said commutator base, and a distal end oriented facing away from said commutator base.

A motor armature comprising:

• a motor shaft;
• a commutator concentrically mounted on said motor shaft, said commutator including a base;
• an annular conductive member encircling said motor shaft and positioned at said commutator base;
• an annular varistor disk encircling said motor shaft and positioned adjacent to said conductive member;
• and
• a non-conductive retaining ring, said retaining ring having an axial bore therethrough dimensioned to provide a friction fit with the motor shaft, a proximal end oriented facing towards said commutator base, and a distal end oriented facing away from said commutator base wherein said proximal end of said retaining ring is necked in, and the periphery of said distal end of said retaining ring is formed with at least one planar side, the periphery of said proximal end of said retaining ring is formed with a planar side, and the inner diameter of said varistor disk is provided with a planar side complementary to said planar side of said proximal end of said retaining ring, said planar side of said retaining ring being oriented to result in proper alignment of said varistor disk with said commutator;
• wherein said conductive member and said varistor disk have inner diameters dimensioned to enable them to pass freely over said motor shaft and to receive said proximal end of said retaining ring.