High speed drilling spindle

Claim 2

A high speed drilling spindle for a drilling system, comprising: a fixed spindle body; a rotatable rotor shaft supported within said spindle body for high speed rotation and linear translation along a rotor shaft axis; a chuck assembly for securing a drilling tool at the lower end of the rotor shaft in alignment with the shaft axis; a rotary air bearing means for supporting the rotor shaft for high speed rotation with low frictional drag within said spindle body; a rotary motor for imparting rotational drive forces to said rotor shaft so as to rotate said shaft on said rotary air bearing at high speeds; a linear drive means for imparting an axially directed drive force to drive said along said shaft axis to perform drilling movements; and means for coupling said linear drive means to said rotor shaft to impart said drive force to said rotor shaft, said means comprising a thrust bearing and a linear air bearing; whereby said rotor shaft may be rotated at high speeds by said rotary motor and simultaneously translated along said axis to perform said drilling movements.

Claim 3

The drilling spindle of claim 1 wherein said rotary motor comprises an electric motor having a stator comprising a ferrous stator core encircling said rotor shaft and a plurality of stator windings of electrically conductive wire wound about axial slots formed in said core about said rotor shaft and a rotor comprising an elongated rotor region to conduct the rotor electrical currents, said region extending along said rotor shaft in the region encircled by said stator and having an elongated length such that the rotor length overlaps the stator length by a sufficient length to enable the rotor shaft to translate along a range of movement without significant degradation of the rotary motor function.

Claim 4

The drilling spindle of claim 2 wherein said elongated rotor region is formed by a plurality of elongated copper bars extending along the outer periphery of the rotor shaft in axial slots and which are connected on each end by copper rings embedded in the rotor shaft outer periphery.

Claim 5

The spindle of claim 3 wherein said rotary air bearing means comprises an upper sleeve member fixed within the spindle body and encircling an upper portion of said rotor shaft, a plurality of air orifices formed in said sleeve, and means for coupling said orifices to a supply of pressurized air.

Claim 6

The spindle of claim 1 wherein said rotary air bearing means comprises a lower sleeve member fixed within the spindle body and encircling a lower portion of said rotor shaft, a plurality of air orifices formed in said sleeve, and means for coupling said orifices to a supply of pressurized air.

Claim 7

The spindle of claim 1 further comprising a coolant system for conducting heat away from the spindle in the region of the rotary motor during high speed operation.

Claim 8

The spindle of claim 6 wherein said coolant system comprises a plurality of coolant passages about the rotary motor, and means for conducting a coolant fluid through said passages.

Claim 9

The spindle of claim 7 wherein said coolant system further comprises a pump for pumping the coolant to the passages and a heat exchanger coupled to a coolant outlet port for extracting heat energy from the exhausted fluid.

Claim 10

The spindle of claim 1 wherein said linear drive means comprises a linear motor having: a moving coil assembly having means for connection to a motor driver; a stator assembly comprising a permanent magnet assembly for co-action with said moving coil assembly to develop axially directed drive forces on said moving coil assembly in response to motor drive signals; and means for coupling said moving coil assembly to said rotor shaft for imparting said axial forces to said rotor shaft.

Claim 11

The spindle of claim 9 wherein said moving coil assembly comprises a metal cylinder having a conductive wire wound around the periphery thereof, with said wire being coupled to said motor driver, and wherein an electromotive force is exerted in an axial direction on the moving coil assembly in response to motor drive signals applied thereto.

Claim 12

The spindle of claim 9 wherein said means for coupling said moving coil assembly to said rotor shaft comprises a plunger having one end coupled to said rotor shaft by said thrust bearing and the other end coupled to said moving coil assembly, whereby said axial forces on the moving coil assembly are transmitted to said rotor shaft.

Claim 13

The spindle of claim 11 wherein said plunger is mounted within the spindle body on an air bearing, and the thrust bearing comprises an air bearing for coupling the rotor shaft to the plunger so as to reduce frictional drag between the rotor shaft and the plunger.

Claim 14

The spindle of claim 12 wherein said plunger is mounted within the spindle body for axial movement, and is coupled to said moving coil assembly by an anti-rotation bearing for preventing the plunger from rotating.

Claim 15

The spindle of claim 2 further comprising means for biasing the rotor shaft against the force of gravity so as to equalize the force required to be exerted by the linear motor to axially translate the rotor shaft in either axial direction.

Claim 16

The spindle of claim 14 wherein said position biasing means comprises a biasing spring means for supporting the weight of the rotor shaft.

Claim 17

The spindle of claim 1 further comprising a position sensor for providing a position signal indicative of a relative axial position of the rotor shaft.

Claim 18

The spindle of claim 16 further comprising a velocity sensor for providing a velocity signal indicative of the velocity of the rotor shaft along said shaft axis.

Claim 19

The spindle of claim 1 further comprising a rotary speed transducer for providing signals indicative of the rotational speed of the rotor shaft.

Claim 20

A high speed drilling spindle for a drilling system, comprising: a fixed spindle body; a rotatable rotor shaft supported within said spindle body for high speed rotation and linear translation along a rotor shaft axis; rotary fluid bearing means for supporting the rotor shaft for high speed rotation with low friction drag within said spindle body; means for securing a drilling tool at a first end of the rotor shaft in alignment with the shaft axis; means for imparting rotational drive forces to said rotor shaft so as to rotate said rotor shaft at high speeds; a linear motor drive means for imparting an axially directed drive force to drive said rotor shaft along said shaft axis to perform drilling movements; and means for coupling said linear drive means to said rotor shaft to impart said drive force to said rotor shaft, said means comprising a thrust bearing which in turn comprises an air bearing; whereby said rotor shaft may be rotated at high speeds by said rotary drive means and simultaneously translated along said axis to perform said drilling movements.

Claim 21

A high speed drilling spindle for a drilling system, comprising: a fixed spindle body; a rotatable rotor shaft supported within said spindle body for high speed rotation and linear translation along a rotor shaft axis; rotary fluid bearing means for supporting the rotor shaft for high speed rotation with low friction drag within said spindle body; means for securing a drilling tool at a first end of the rotor shaft in alignment with the shaft axis; means for imparting rotational drive forces to said rotor shaft so as to rotate said rotor shaft at high speeds; a linear motor drive means for imparting an axially directed drive force to drive said rotor shaft along said shaft axis to perform drilling movements; and means for coupling said linear drive means to said rotor shaft to impart said drive force to said rotor shaft, said means comprising a thrust bearing which in turn comprises an air bearing; whereby said rotor shaft may be rotated at high speeds by said rotary drive means and simultaneously translated along said axis to perform said drilling movements.

Claim 22

The spindle of claim 19 wherein said linear motor drive means comprises: a moving coil assembly having means for connection to a motor driver; and a stator assembly comprising a permanent magnet assembly for co-action with said moving coil assembly to develop axially directed drive forces on said moving coil assembly in response to motor drive signals; and said coupling means comprises means for coupling said moving coil assembly to said rotor shaft for imparting said axial forces to said shaft.

Claim 23

The spindle of claim 20 wherein said moving coil assembly comprises a metal cylinder having a conductive wire wound around the periphery thereof, with said wire being coupled to said motor driver, and wherein an electromotive force is exerted in an axial direction on the moving coil assembly in response to motor drive signals applied thereto.

Claim 24

The spindle of claim 20 wherein said means for coupling said moving coil assembly to said rotor shaft further comprises a plunger having one end coupled to a second end of said rotor shaft by said thrust bearing and the other end coupled to said moving coil assembly, whereby said axial forces on the moving coil assembly are transmitted to said rotor shaft.

Claim 25

The spindle of claim 22 wherein said air bearing is for coupling the rotor shaft to the plunger so as to reduce frictional drag between the rotor shaft and the plunger.

Claim 26

The spindle of claim 19 further comprising means for biasing the rotor shaft against the force of gravity so as to equalize the force required to be exerted by the linear motor to axially translate the rotor shaft in either axial direction.

Claim 27

The spindle of claim 24 wherein said position biasing means comprises a biasing spring means for supporting the weight of the rotor shaft.

Claim 28

The spindle of claim 19 further comprising a position sensor directly coupled to the rotor shaft for providing a position signal directly related to a relative axial position of the rotor shaft.

Claim 29

The spindle of claim 19 further comprising a velocity sensor directly coupled to the rotor shaft for providing a velocity signal directly related to the velocity of the rotor shaft along said shaft axis.

Claim 30

The spindle of claim 19 further comprising a rotary speed transducer for providing signals indicative of the rotational speed of the rotor shaft.

Claim 31

The drilling spindle of claim 19 wherein said rotational drive means comprises an electric motor having a stator comprising a ferrous stator core encircling said rotor shaft and a plurality of stator windings of electrically conductive wire wound about axial slots formed in said core about said rotor shaft, and a rotor comprising an elongated rotor region to conduct the rotor electrical currents, said region extending along said rotor shaft in the region encircled by said stator and having an elongated length such that the rotor length overlaps the stator length by a sufficient length to enable the rotor shaft to translate along a range of movement without significant degradation of the rotary motor function.

Claim 32

The drilling spindle of claim 29 wherein said elongated rotor region is formed by a plurality of elongated copper bars extending along the outer periphery of the rotor shaft in axial slots and which are connected on each end by copper rings embedded in the rotor shaft outer periphery.

Claim 33

The spindle of claim 19 further comprising a rotary air bearing for supporting the rotor shaft for high speed rotation with low frictional drag within said spindle body, said air bearing comprising an upper sleeve member fixed within the spindle body and encircling an upper portion of said motor shaft, a plurality of air orifices formed in said sleeve, and means for coupling said orifices to a supply of pressurized air.

Claim 34

The spindle of claim 31 wherein said rotary air bearing means comprises a lower sleeve member fixed within the spindle body and encircling a lower portion of said motor shaft, a plurality of air orifices formed in said sleeve, and means for coupling said orifices to a supply of pressurized air.

Claim 35

The spindle of claim 19 further comprising a coolant system for conducting heat away from the spindle in the region of the rotary drive means during high speed operation.

Claim 36

The spindle of claim 33 wherein said coolant system comprises a plurality of coolant passages about the rotary drive means, and means for conducting a coolant fluid through said passages.

Claim 37

The spindle of claim 34 wherein said coolant system further comprises a pump for pumping the coolant to the passage and a heat exchanger coupled to a coolant outlet port for extracting heat energy from the exhausted fluid.

Claim 38

A high speed drilling spindle for a drilling system, comprising: a fixed spindle body; a rotatable rotor shaft supported within said spindle body for high speed rotation and linear translation along the rotor shaft axis; first and second rotary fluid bearings fixed with respect to the linear translation of said rotor axis, said bearings separated by a fixed distance for supporting the rotor shaft for high speed rotation with low frictional drag within said spindle body; means for securing a drilling tool at a first end of the rotor shaft in alignment with the shaft axis; means for imparting rotational drive forces to said rotor shaft so as to rotate said rotor shaft at high speeds; linear drive means for imparting an axially directed drive force to drive said rotor shaft along said rotor shaft axis to perform drilling movements; means for coupling said linear drive means to said rotor shaft to transfer said axially directed drive force to said rotor shaft, said means comprising a thrust bearing which is not required to sustain any substantial radial load, wherein said rotor shaft may be rotated a high speeds by said rotary drive means and simultaneously translated along said axis with high dynamic stability to perform said drilling movements.

Claim 39

A high speed drilling spindle for a drilling system, comprising: a fixed spindle body; a rotatable rotor shaft supported within said spindle body for high speed rotation and linear translation along the rotor shaft axis; first and second rotary fluid bearings fixed with respect to the linear translation of said rotor axis, said bearings separated by a fixed distance for supporting the rotor shaft for high speed rotation with low frictional drag within said spindle body; means for securing a drilling tool at a first end of the rotor shaft in alignment with the shaft axis; means for imparting rotational drive forces to said rotor shaft so as to rotate said rotor shaft at high speeds; linear drive means for imparting an axially directed drive force to drive said rotor shaft along said rotor shaft axis to perform drilling movements; means for coupling said linear drive means to said rotor shaft to transfer said axially directed drive force to said rotor shaft, said means comprising a thrust bearing which is not required to sustain any substantial radial load, wherein said rotor shaft may be rotated a high speeds by said rotary drive means and simultaneously translated along said axis with high dynamic stability to perform said drilling movements.

Claim 40

The drilling spindle of claim 36 wherein said rotary motor comprises an electric motor having a stator comprising a ferrous stator core encircling said rotor shaft and a plurality of stator windings of electrically conductive wire wound about axial slots formed in said core about said rotor shaft, and a rotor comprising an elongated rotor region to conduct the rotor electrical currents, said region extending along said rotor shaft in the region encircled by said stator and having an elongated length such that the rotor length overlaps the stator length by a sufficient length to enable the rotor shaft to translate along a range of movement without significant degradation of the rotary motor function.

Claim 41

The drilling spindle of claim 37 wherein said elongated rotor region is formed by a plurality of elongated copper bars extending along the outer periphery of the rotor shaft in axial slots and which are connected on each end by copper rings embedded in the rotor shaft outer periphery.

Claim 42

The spindle of claim 38 wherein said rotary air bearing means comprises an upper sleeve member fixed within the spindle body and encircling an upper portion of said rotor shaft, a plurality of air orifices formed in said sleeve, and means for coupling said orifices to a supply of pressurized air.

Claim 43

The spindle of claim 36 wherein said first rotary fluid bearing means comprises a lower sleeve member fixed within the spindle body and encircling a lower portion of said rotor shaft, a plurality of fluid orifices formed in said sleeve, and means for coupling said orifices to a supply of pressurized fluid.

Claim 44

The spindle of claim 36 wherein said second rotary fluid bearing means comprises an upper sleeve member fixed within the spindle body and encircling an upper portion of said rotor shaft, a plurality of fluid orifices formed in said sleeve, and means for coupling said orifices to a supply of pressurized fluid.

Claim 45

The spindle of claim 36 wherein said linear drive means comprises a linear motor having: a moving coil assembly having means for connection to a motor driver; a stator assembly comprising a permanent magnet assembly for co-action with said moving coil assembly to develop axially directed drive forces on said moving coil assembly in response to motor drive signals; and means for coupling said moving coil assembly to said rotor shaft for impairing said axial forces to said rotor shaft.

Claim 46

The spindle of claim 42 wherein said moving coil assembly comprises a metal cylinder having a conductive wire wound around the periphery thereof, with said wire being coupled to said motor driver, and wherein an electromotive force is exerted in an axial direction on the moving coil assembly in response to motor drive signals applied thereto.

Claim 47

The spindle of claim 42 wherein said means for coupling said moving coil assembly to said rotor shaft comprises a plunger member having one end coupled to said rotor shaft by said thrust bearing and the other end coupled to said moving coil assembly, whereby said axial forces on the moving coil assembly are transmitted to said rotor shaft.

Claim 48

The spindle of claim 44 wherein said plunger is mounted within the spindle body on an air bearing, and the thrust bearing comprises an air bearing for coupling the rotor shaft to the plunger so as to reduce frictional drag between the rotor shaft and the plunger.

Claim 49

The spindle of claim 45 wherein said plunger is mounted within the spindle body for axial movement, and is coupled to said moving coil assembly by an anti-rotation bearing for preventing the plunger from rotating.

Claim 50

The spindle of claim 37 further comprising means for biasing the axial rotor shaft position against the force of gravity so as to equalize the force required to be exerted by the linear motor to axially translate the rotor shaft in either axial direction.

Claim 51

The spindle of claim 47 wherein said position biasing means comprises a biasing spring means for supporting the weight of the rotor shaft.

Claim 52

The spindle of claim 36 wherein said rotor is rotatable at speeds of 80,000 revolutions per minute or higher.

Claim 53

A high speed drilling spindle for a drilling system comprising: a fixed spindle body; a rotatable rotor shaft supported within said spindle body for high speed rotation and linear translation along the rotor shaft axis; means for securing a drilling tool at a first end of the rotor shaft in alignment with the shaft axis; means for imparting rotational drive forces to said rotor shaft so as to rotate said rotor shaft at high speeds; a linear motor drive means for imparting an axially directed drive force to drive said rotor shaft along said shaft axis to perform drilling movements, said linear motor drive means comprising a moving coil assembly having means for connection to a motor driver, a stator assembly comprising a permanent magnet assembly for co-action with said moving coil assembly to develop axially directed drive forces on said moving coil assembly in response to motor drive signals, and means for coupling said moving coil assembly to said rotor shaft for imparting said axial forces to said shaft; wherein said means for coupling said moving coil assembly to said rotor shaft comprises a thrust bearing and a plunger having one end coupled to a second end of said rotor shaft by said thrust bearing and the other end coupled to said moving coil assembly, and whereby said axial forces on the moving coil assembly are transmitted to said rotor shaft, and wherein said plunger is mounted within the spindle body on an air bearing, and the thrust bearing comprises an air bearing for coupling the rotor shaft to the plunger so as to reduce frictional drag between the rotor shaft and the plunger; whereby said rotor shaft may be rotated at high speeds by said rotary drive means and simultaneously translated along said axis to perform said drilling movements.

Claim 54

A high speed drilling spindle for a drilling system comprising: a fixed spindle body; a rotatable rotor shaft supported within said spindle body for high speed rotation and linear translation along the rotor shaft axis; means for securing a drilling tool at a first end of the rotor shaft in alignment with the shaft axis; means for imparting rotational drive forces to said rotor shaft so as to rotate said rotor shaft at high speeds; a linear motor drive means for imparting an axially directed drive force to drive said rotor shaft along said shaft axis to perform drilling movements, said linear motor drive means comprising a moving coil assembly having means for connection to a motor driver, a stator assembly comprising a permanent magnet assembly for co-action with said moving coil assembly to develop axially directed drive forces on said moving coil assembly in response to motor drive signals, and means for coupling said moving coil assembly to said rotor shaft for imparting said axial forces to said shaft; wherein said means for coupling said moving coil assembly to said rotor shaft comprises a thrust bearing and a plunger having one end coupled to a second end of said rotor shaft by said thrust bearing and the other end coupled to said moving coil assembly, and whereby said axial forces on the moving coil assembly are transmitted to said rotor shaft, and wherein said plunger is mounted within the spindle body on an air bearing, and the thrust bearing comprises an air bearing for coupling the rotor shaft to the plunger so as to reduce frictional drag between the rotor shaft and the plunger; whereby said rotor shaft may be rotated at high speeds by said rotary drive means and simultaneously translated along said axis to perform said drilling movements.

Claim 55

The spindle of claim 50 wherein said plunger is mounted within the spindle body for axial movement, and is coupled to said moving coil assembly by an anti-rotation bearing for preventing the plunger from rotating.