Air operated tool

Claim 2

Preloading means for a motor having a rotor to which a rotary tool is adapted to be connected, a stator and motor housing assembly in which said rotor is rotatably supported by ball bearings adjacent the ends of said stator, said bearings having inner rings axially fixed on said rotor and outer rings closely fitted in said assembly, said means comprising spring means exerting axial separating force between one outer ring and the adjacent end of said stator while the other outer ring abuts the other end of said stator to relatively axially move said staTor and the other outer ring and said rotor and inner rings thus to takeup axial play in both bearings and to preload them by imposition of tensile load on said rotor.

Claim 3

Preloading means for a motor having a rotor to which a rotary tool is adapted to be connected, a stator and motor housing assembly in which said rotor is rotatably supported by ball bearings adjacent the ends of said stator, said bearings having inner rings axially fixed on said rotor and outer rings closely fitted in said assembly, said means comprising spring means exerting axial separating force between one outer ring and the adjacent end of said stator while the other outer ring abuts the other end of said stator to relatively axially move said staTor and the other outer ring and said rotor and inner rings thus to takeup axial play in both bearings and to preload them by imposition of tensile load on said rotor.

Claim 4

Preloading means for a motor having a rotor to which a rotary tool is adapted to be connected, a stator and motor housing assembly in which said rotor is rotatably supported by ball bearings adjacent the ends of said stator, said bearings having inner rings axially fixed on said rotor and outer rings closely fitted in said assembly, said means comprising spring means exerting axial separating force between one outer ring and the adjacent end of said stator while the other outer ring abuts the other end of said stator to relatively axially move said staTor and the other outer ring and said rotor and inner rings thus to takeup axial play in both bearings and to preload them by imposition of tensile load on said rotor.

Claim 5

The preloading means of claim 1 wherein said spring means comprises a Belleville spring.

Claim 6

The preloading means of claim 2 characterized in that the Belleville spring is deflected from dished form to flattened form and springs back to partly dished form to maintain a substantially constant preload on said bearings despite tolerance variations in the axial play of said bearings and despite wear of said bearings in use.

Claim 7

The preloading means of claim 2 characterized in that said Belleville spring when deflected from dished form to flat form during assembly of said motor exerts, upon spring back to partly dished form, a substantially constant preload on said bearings despite tolerance variation in the axial play of said bearings and despite axial wear of said bearings during use.

Claim 8

An air operated tool comprising a tubular housing having an air motor therewithin including a stator assembly comprising a tubular stator and end plates abutting the ends of said stator and defining therewith a motor chamber, a rotor journaled in said housing having radially movable vanes thereon engaged with an eccentrically disposed bore in said stator and being adapted to mount a rotary tool at one end thereof, a first ball bearing having an inner ring axially fixedly secured on said rotor and an outer ring in abutting engagement with one end plate, a second ball bearing having an inner ring axially fixedly secured on said rotor and an outer ring which is closely slidably fitted in the other end plate, said housing and stator and other end plate defining a passage for supply of air under pressure to said motor chamber to effect rotation of said rotor, and spring means between the outer ring of said second bearing and said other end plate exerting axial separating force effecting relative axial movement of said rotor and inner rings and said end plates, stator and outer bearing ring of said first bearing thus to take up axial play in both bearings and to preload them by imposition of tensile load on said rotor.

Claim 9

An air operated tool comprising a tubular housing having an air motor therewithin including a stator assembly comprising a tubular stator and end plates abutting the ends of said stator and defining therewith a motor chamber, a rotor journaled in said housing having radially movable vanes thereon engaged with an eccentrically disposed bore in said stator and being adapted to mount a rotary tool at one end thereof, a first ball bearing having an inner ring axially fixedly secured on said rotor and an outer ring in abutting engagement with one end plate, a second ball bearing having an inner ring axially fixedly secured on said rotor and an outer ring which is closely slidably fitted in the other end plate, said housing and stator and other end plate defining a passage for supply of air under pressure to said motor chamber to effect rotation of said rotor, and spring means between the outer ring of said second bearing and said other end plate exerting axial separating force effecting relative axial movement of said rotor and inner rings and said end plates, stator and outer bearing ring of said first bearing thus to take up axial play in both bearings and to preload them by imposition of tensile load on said rotor.

Claim 10

The tool of claim 5 wherein said spring means comprises a Belleville spring.

Claim 11

The tool of claim 6 wherein said Belleville spring is deflected from dished form to flattened form and springs back to partly dished form to maintain a substantially constant preload on said bearings despite tolerance variations in the axial play of said bearings and despite wear of said bearings in use.