Motor shaft discharge device
OwnerRodney R. Fisher, Hugh E. Boyantoninventors
Life of this patent
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Abstract
A grounding system for an AC or DC motor or other rotating apparatus employs a conductive brush in resilient contact with a contamination free conductive member removably secured onto a rotating part such as a motor shaft or tachometer shaft. The contacting surface is preferably formed of brass and is shielded from contamination from motor bearings and the like, for reliably shunting the shaft to the frame of the machine so as to avoid high voltage transients across bearings as would otherwise result in bearing damage or destruction.
Claims42
Apparatus for electrically discharging a rotating shaft, said apparatus comprising:
- contact means providing an electrical contacting surface, said contact means comprising a member distinct from the shaft but removably attached to said shaft for rotation with said shaft and electrically connected thereto;
- said contact means, where it provides said surface, being formed of a conductive material having a substantially higher resistance to corrosion than said rotating shaft to maintain a low electrical resistance, and
- means for holding a conductive brush in resilient and continuous frictional contact with said contacting surface to provide a continuous low impedance frictional contact with said contacting surface so as to provide a continuous electrical discharge path for said shaft.
Apparatus for electrically discharging a rotating shaft of a machine, said machine having a frame supporting bearings journalling said shaft, said apparatus comprising:
- contact means providing an electrical contacting surface, said contact means comprising a member distinct from the shaft but removably attached to said shaft for rotation with said shaft and electrically connected thereto;
- said contact means, where it provides said surface, being formed of a durable, highly conductive, corrosion resistant material adapted for providing a low resistance connection to avoid sources of corrosion and/or contamination characteristic of making connection with the shaft itself;
- and
- means for holding a conductive brush in resilient and continuous frictional contact with said contacting surface to complete a continuous, low resistance frictional contact with said contacting surface, said brush being grounded to said frame so as to provide a continuous, low-impedance electrical discharge path for said shaft across said bearings for fully shorting said shaft to ground and avoiding high voltage transients across said bearings as induced in said shaft that would cause pitting of said bearings by high voltage discharge.
An apparatus for electrically discharging a rotating shaft of a machine, said machine having a frame supporting bearings journalling said shaft, said apparatus comprising:
- contact means providing an electrical contacting surface, said contact means comprising an extension shaft rotatably secured to said rotating shaft;
- said contact means, where it provides said surface, being formed of a durable, highly conductive, corrosion resistant material adapted for providing a low resistance connection to avoid sources of corrosion and/or contamination characteristic of making connection with the shaft itself;
- and
- means for holding a conductive brush in resilient and continuous frictional contact with said contacting surface to complete a continuous, low resistance frictional contact with said contacting surface, said brush being grounded to said frame so as to provide a continuous, low-impedance electrical discharge path for said shaft across said bearings for fully shorting said shaft to ground and avoiding high voltage transients across said bearings as induced in said shaft that would cause pitting of said bearings by high voltage discharge.
Apparatus for electrically discharging a rotating shaft, said apparatus comprising:
- contact means providing an electrical contacting surface, said contact means comprising an extension shaft rotatably secured to said rotating shaft;
- said contact means, where it provides said surface, being formed of a conductive material having a substantially higher resistance to corrosion than said rotating shaft to maintain a low electrical resistance, and
- means for holding a conductive brush in resilient and continuous contact with said contacting surface so as to provide a continuous electrical discharge path for said shaft, said holding means urging said brush radially toward the axis of said extension shaft to engage the side of said extension shaft providing said contacting surface.
Apparatus for electrically discharging a rotating shaft of a machine, said machine having a frame supporting bearings journalling said shaft, said shaft having an end displaced from said bearings,
- said end of said shaft having a contacting surface,
- said apparatus including means for holding a conductive brush directly in resilient and continuous frictional contact with said contacting surface at the end of said shaft so as to provide a continuous electrical discharge path for said shaft,
- wherein said holding means urges said brush in a direction substantially longitudinal of said shaft toward said contacting surface.
Dependencies are inferred from the claim text.