Motor and method for manufacturing the same
AssigneeNidec Corporation
InventorYoshikazu Ichiyama
Life of this patent
Estimating the term…
Abstract
A motor includes a stationary shaft, a stationary thrust plate fixed to the stationary shaft and a rotor adapted to rotate about the stationary shaft and stationary thrust plate. A rotary thrust plate is fixed within an upper opening of the rotor facing an upper surface of the stationary thrust plate. Portions of a surface of each of the stationary and rotary thrust plates and lubricant therebetween define an upper thrust bearing. The rotary thrust plate is formed with a lubricant injection hole that allows for simple manufacturing steps wherein the motor is completely assembled before lubricant is injected through the lubricant injection hole into the upper thrust bearing and a lower thrust bearing defined between portions of adjacent surfaces of the stationary thrust plate and the rotor.
Claims15
A motor comprising:
- a shaft;
- a substantially disk-shaped thrust plate fitted to a portion of said shaft extending radially outward therefrom;
- a substantially cylindrical sleeve member having a central opening extending therethrough adapted to receive said shaft and a portion of said thrust plate such that a first small gap is formed between portions of said shaft and said sleeve member, said first small gap being continuous with a second small gap formed between said thrust plate and said sleeve member;
- a second thrust plate adapted to be rigidly coupled to a surface defining said central opening of said sleeve member with one end of said shaft extending through a central opening of said second thrust plate, said second thrust plate being formed with at least one first lubricant injection bore;
- and
- wherein
- a lubricant is disposed in said first and second gaps,
- adjacent surfaces of said shaft and said sleeve member, said first gap and said lubricant therein, and, adjacent surfaces of said thrust plate and said sleeve member, said second gap and said lubricant therein, define a plurality of hydrodynamic bearings, said hydrodynamic bearings adapted to provide support between said shaft and said sleeve member for relative rotary displacement therebetween, and
- said first lubricant injection bore is open to a radially outward portion of one of said hydrodynamic bearings proximate a radially outward portion of said thrust plate, and to an upper surface of said second thrust plate, so as to communicate said first gap and said second gap with outside air.
An spindle motor comprising:
- a stationary shaft having a shaft portion and a disk-shaped stationary thrust plate fixed thereto, said shaft portion extending from a base to a distal end thereof, and said stationary thrust plate formed proximate the distal end of said shaft portion, said shaft portion being further formed with at least one radial bearing surface;
- a rotor having at least one journal portion, said rotor being formed with a recess which defines a first thrust surface, said journal portion having an inner radial surface facing said radial bearing surface of said shaft portion, and said first thrust surface axially facing a lower surface of said thrust plate, portions of said first thrust surface and said lower surface of said thrust plate defining a lower thrust bearing, said journal portion and said radial bearing surface defining at least one radial bearing;
- a rotary thrust plate fixed within an opening of said rotor axially aligned with said stationary shaft, a lower surface of said rotary thrust plate defining a second thrust surface that axially faces an upper surface of said thrust plate, portions of said second thrust surface and said upper surface of said thrust plate defining an upper thrust bearing;
- and
- wherein said recess in said rotor and an outer circumferentially extending surface of said stationary thrust plate further defines a lubricant filled gap open to both said upper and lower thrust bearings, and said rotary thrust plate is formed with a first lubricant injection bore that extends from a radially outward portion of said lubricant filled gap to an upper surface of said rotary thrust plate so as to form a vent for said lubricant filled gap.
Dependencies are inferred from the claim text.