Rotational coupling device with improved drive key retention structure

A rotational coupling device, comprising:

• a rotor disposed about an input shaft, said input shaft disposed about a rotational axis and said rotor and said input shaft defining opposed keyways;
• a key disposed within said opposed keyways of said rotor and said input shaft, said key rotatably coupling said rotor and said input shaft;
• an armature disposed about said axis, said armature coupled to an output member and configured for selective engagement with said rotor;
• and,
• a first support member disposed about said axis and configured to receive said key
• wherein said key and said first support member are shaped complementary to one another to limit radial movement of said key relative to said first support member in a first radial direction and to limit axial movement of said key relative to said first support member in a first axial direction, said key defining a radially inner portion and a radially outer portion, one of said radially inner and radially outer portions extending axially further than another of said radially inner and radially outer portions and defining an axially extending surface intermediate the radially innermost and radially outermost surfaces of said key, said axially extending surface terminating at a radially extending surface in said another of said radially inner and radially outer portions to thereby define a first shoulder, said first shoulder abutting a second shoulder formed in said first support member at an intersection of a radially extending surface in an axial end face of said first support member and an axially extending surface of said first support member.

A rotational coupling device, comprising:

• a rotor disposed about an input shaft, said input shaft disposed about a rotational axis and said rotor and said input shaft defining opposed keyways;
• a key disposed within said opposed keyways of said rotor and said input shaft, said key separable from said rotor and rotatably coupling said rotor and said input shaft;
• an armature disposed about said axis, said armature coupled to an output member and configured for selective engagement with said rotor;
• wherein said key and said rotor are shaped complementary to one another to limit radial movement of said key relative to said rotor in a first radial direction away from said rotor;
• and
• a first support member disposed about said axis and configured to receive said key wherein said key and said first support member are shaped complementary to one another to limit radial movement of said key relative to said first support member in one of said first radial direction and a second radial direction opposite said first radial direction and to limit axial movement of said key relative to said first support member in a first axial direction.

A rotational coupling device, comprising:

• a rotor disposed about an input shaft, said input shaft disposed about a rotational axis and said rotor and said input shaft defining opposed keyways;
• a key disposed within said opposed keyways of said rotor and said input shaft, said key separable from said rotor and rotatably coupling said rotor and said input shaft;
• an armature disposed about said axis, said armature coupled to an output member and configured for selective engagement with said rotor;
• wherein said key and said rotor are shaped complementary to one another to limit radial movement of said key relative to said rotor in a first radial direction away from said rotor
• wherein one of a first axial end of said key and a first axial end of said rotor is axially aligned with another of said first axial end of said key and said first axial end of said rotor to limit axial movement of said key relative to said rotor in a first axial direction
• wherein one of a second axial end of said key and a second axial end of said rotor is axially aligned with another of said second axial end of said key and said second axial end of said rotor to limit axial movement of said key relative to said rotor in a second axial direction opposite said first axial direction.