Light deflecting system with rotating mirror

Claim 2

A light scanning system, comprising: a shaft having an axis of rotation; a motor magnet mounted on said shaft; a rigid casing surrounding said shaft; a motor stator mounted on said casing operatively adjacent said motor magnet; a polygonal light reflecting mirror concentrically mounted on said shaft; dynamic gas journal bearing means operatively between said shaft and said casing for rotationally mounting and radially supporting said shaft relative to said casing, said gas bearing means including a rigid annular bearing member separate from and between said casing and said shaft, said gas bearing means further including cooperatingly shaped surface means on the inside of said bearing member and the outside adjacent portion of said shaft for producing dynamic gas pressure therebetween during rotation of said shaft; means for mounting said bearing member on said casing for relative radial movement in all radial directions and for preventing relative rotational movement, with respect to said axis; resilient means between said bearing member and said casing providing resilient relative radial movement between said bearing member and said casing for preventing said shaft from contacting said bearing member during shaft movement relative to said casing at resonant frequency of the rotatable mass; and energy absorbing means between said bearing member and said casing for damping relative movement between said casing and said bearing member during resonant frequency to substantially reduce amplitude of the relative movement at said resonant frequency.

Claim 3

The system according to claim 1, wherein said motor magnet and said motor stator constitute means for rotating said shaft at a speed greater than 100,000 rpm.

Claim 4

The system according to claim 2, wherein one of the surface means of said bearing member and said shaft is noncylindrical and the other is cylindrical.

Claim 5

The system according to claim 2, wherein said shaft and the structure mounted thereon constitute a rotating mass having a natural frequency and a whirling resonance frequency at approximately twice the natural frequency; and wherein said energy absorbing means substantially prevents whirling at said whirling resonance frequency.

Claim 6

The system according to claim 4, wherein said resilient means is a plurality of peripherally spaced springs and said energy absorbing means is a viscous fluid contained in an annular chamber between said casing and said bearing member.

Claim 7

The system according to claim 4, wherein said resilient means and said energy absorbing means is constituted by an elastomeric material with substantial hysteresis.

Claim 8

The system according to claim 4, wherein said resilient means and energy absorbing means are mounted at three equally spaced positions around the periphery of said shaft in a first annular array above said motor stator and motor magnet and a second annular array below said motor stator and said motor magnet.

Claim 9

The system according to claim 1, wherein said motor magnet and said motor stator constitute means for rotating said shaft at a speed greater than 150,000 rpm.

Claim 10

The system according to claim 1, further including said casing being generally cup shaped, and a magnetic thrust bearing between one axial end of said shaft and the adjacent portion of said casing.

Claim 11

The system according to claim 1, wherein one of the surface means of said bearing member and said shaft is noncylindrical and the other is cylindrical.

Claim 12

The system according to claim 10, further including a plurality of grooves in one of said surface means of said bearing member and said shaft to constitute means for enhancing dynamic gas pressure during rotation of said shaft.

Claim 13

The system according to claim 11, wherein said grooves are arranged in peripherally spaced relationship to each other in an annular array, with each groove of the array being elongated in the axial direction parallel to each other and at an acute angle With respect to the axial direction.

Claim 14

The system according to claim 12, wherein additional ones of said grooves are arranged in peripherally spaced relationship to each other in a second annular array, with each groove of the second array being elongated in the axial direction parallel to each other and at an acute angle symmetrical to the first mentioned acute angle, with respect to the axial direction.

Claim 15

A high speed motor system, comprising: a shaft having an axis of rotation; a motor magnet mounted on said shaft to define a rotatable mass; a rigid casing surrounding said shaft; a motor stator mounted on said casing operatively adjacent said motor magnet; dynamic gas journal bearing means operatively between said shaft and said casing for rotationally mounting and radially supporting said shaft relative to said casing, said gas bearing means including a bearing member separate from and between said casing and said shaft, said gas bearing means further including cooperatingly shaped surface means on the inside of said bearing member and the outside adjacent portion of said shaft for producing dynamic gas pressure there between during rotation of said shaft; means for mounting said bearing member on said casing for relative radial movement in all radial directions and for preventing relative rotational movement, with respect to said axis; resilient means between said bearing member and said casing providing resilient relative radial movement between said bearing member and said casing for preventing said shaft from contacting said bearing member during shaft movement relative to said casing at resonant frequency of the rotatable mass; energy absorbing means between said bearing member and said casing for damping relative movement between said casing and said bearing member during resonant frequency to substantially reduce amplitude of the relative movement at said resonant frequency; said motor magnet and said motor stator constituting means for rotating said shaft at a speed greater than 100,000 rpm; one of the surface means of said bearing member and said shaft being non-cylindrical and the other being cylindrical; said shaft and the structure mounted thereon constituting a rotating mass having a natural frequency and a whirling resonance frequency at approximately twice the natural frequency; and said energy absorbing means substantially preventing whirling at said whirling resonance frequency.

Claim 16

A high speed motor system, comprising: a shaft having an axis of rotation; a motor magnet mounted on said shaft to define a rotatable mass; a rigid casing surrounding said shaft; a motor stator mounted on said casing operatively adjacent said motor magnet; dynamic gas journal bearing means operatively between said shaft and said casing for rotationally mounting and radially supporting said shaft relative to said casing, said gas bearing means including a bearing member separate from and between said casing and said shaft, said gas bearing means further including cooperatingly shaped surface means on the inside of said bearing member and the outside adjacent portion of said shaft for producing dynamic gas pressure there between during rotation of said shaft; means for mounting said bearing member on said casing for relative radial movement in all radial directions and for preventing relative rotational movement, with respect to said axis; resilient means between said bearing member and said casing providing resilient relative radial movement between said bearing member and said casing for preventing said shaft from contacting said bearing member during shaft movement relative to said casing at resonant frequency of the rotatable mass; energy absorbing means between said bearing member and said casing for damping relative movement between said casing and said bearing member during resonant frequency to substantially reduce amplitude of the relative movement at said resonant frequency; said motor magnet and said motor stator constituting means for rotating said shaft at a speed greater than 100,000 rpm; one of the surface means of said bearing member and said shaft being non-cylindrical and the other being cylindrical; said shaft and the structure mounted thereon constituting a rotating mass having a natural frequency and a whirling resonance frequency at approximately twice the natural frequency; and said energy absorbing means substantially preventing whirling at said whirling resonance frequency.

Claim 17

The system according to claim 14, wherein said bearing member is a single piece rigid construction.

Claim 18

The system according to claim 15, wherein said bearing member is annular.

Claim 19

A bearing system, comprising: a shaft having an axis of rotation; a motor magnet mounted on said shaft; a rigid casing surrounding said shaft; dynamic gas journal bearing means operatively between said shaft and said casing for rotationally mounting and radially supporting said shaft relative to said casing, said gas bearing means including a rigid annular bearing member separate from and between said casing and said bearing shaft, said gas bearing means further including cooperatingly shaped surface means on the inside of said bearing member and the outside adjacent portion of said shaft for producing dynamic gas pressure therebetween during rotation of said shaft; means for mounting said bearing member on said casing for relative radial movement in all directions and for preventing relative rotational movement, with respect to said axis; resilient means between said bearing member and said casing providing resilient relative radial movement between said bearing member and said casing for preventing said shaft from contacting said bearing member during shaft movement relative to said casing at resonant frequency of said shaft; energy absorbing means between said bearing member and said casing for damping relative radial movement between said casing and said bearing member during resonant frequency to substantially reduce amplitude of the relative movement at said resonant frequency; said motor magnet and said motor stator constituting means for rotating said shaft at a speed greater than 100,000 rpm; one of the surface means of said bearing member and said shaft being non-cylindrical and the other being cylindrical; said shaft and the structure mounted thereon constituting a rotating mass having a natural and a whirling resonance frequency at approximately twice the natural frequency; and wherein said energy absorbing means substantially prevents whirling at said whirling resonance frequency.

Claim 20

A bearing system, comprising: a shaft having an axis of rotation; a motor magnet mounted on said shaft; a rigid casing surrounding said shaft; dynamic gas journal bearing means operatively between said shaft and said casing for rotationally mounting and radially supporting said shaft relative to said casing, said gas bearing means including a rigid annular bearing member separate from and between said casing and said bearing shaft, said gas bearing means further including cooperatingly shaped surface means on the inside of said bearing member and the outside adjacent portion of said shaft for producing dynamic gas pressure therebetween during rotation of said shaft; means for mounting said bearing member on said casing for relative radial movement in all directions and for preventing relative rotational movement, with respect to said axis; resilient means between said bearing member and said casing providing resilient relative radial movement between said bearing member and said casing for preventing said shaft from contacting said bearing member during shaft movement relative to said casing at resonant frequency of said shaft; energy absorbing means between said bearing member and said casing for damping relative radial movement between said casing and said bearing member during resonant frequency to substantially reduce amplitude of the relative movement at said resonant frequency; said motor magnet and said motor stator constituting means for rotating said shaft at a speed greater than 100,000 rpm; one of the surface means of said bearing member and said shaft being non-cylindrical and the other being cylindrical; said shaft and the structure mounted thereon constituting a rotating mass having a natural and a whirling resonance frequency at approximately twice the natural frequency; and wherein said energy absorbing means substantially prevents whirling at said whirling resonance frequency.

Claim 21

The system according to claim 17, wherein said motor magnet and said motor stator constitute means for rotating said shaft at a speed greater than 150,000 rpm.

Claim 22

The system according to claim 18, wherein said resilient means is a plurality of peripherally spaced springs and said energy absorbing means is a viscous fluid contained in an annular chamber between said casing and said bearing member.

Claim 23

The system according to claim 18, wherein said resilient means and said energy absorbing means is constituted by an elastomeric material with substantial hysteresis.