JP4845114B2 - Spindle device - Google Patents

Description

  The present invention relates to a spindle device for use in a motor, a machine tool, a medical device, and the like, and more particularly, to a spindle device in which a motor function using fluid energy and a hydrostatic bearing function are integrated.

Many spindle devices of general machine tools are supported by rolling bearings, and transmit the rotational motion of an electric drive motor provided separately from the spindle device via a transmission element such as a belt or a pulley. When the spindle device having such a configuration is used in a precise machine tool system, the following problems occur.
First, it is difficult not only to realize high-precision rotational movement due to friction and mechanical play in the rolling bearing, but also to cause seizure of the rolling bearing during high-speed rotation required in ultra-precision machining. Therefore, it is necessary to adopt a system in which the spindle is supported by the hydrostatic bearing.
Second, when the spindle rotates at high speed, vibrations generated by transmission elements such as belts and pulleys are transmitted to the spindle, causing the spindle itself to vibrate. Therefore, an electric motor or turbine is attached to the spindle itself, and fluid is sprayed onto it. Depending on the system, it is necessary to adopt a system that does not require a mechanical transmission element such as a belt.
Third, when the spindle is used in a machine tool, frictional heat generated between the tool and the work material during machining is transferred to the spindle, causing thermal expansion of the spindle, which causes machining errors, so that the spindle device Need to be cooled.
As a spindle device for dealing with these problems, the present inventor has previously proposed a motor-integrated spindle device disclosed in Patent Document 1.
JP 2003-191142 A

As described above, a spindle device used in a machine tool that performs high-precision machining needs to have a support function using a hydrostatic bearing, a motor function that causes the spindle to rotate by the energy of fluid, and a cooling function. become.
The spindle device in Patent Document 1 has a motor function and a cooling function for causing the spindle to rotate by the energy of fluid, and solves these problems. However, this spindle device can only be rotated in one direction determined by the spindle structure. In addition, there is a problem that the rotation angle cannot be controlled, such as an indexing operation or stopping during rotation.

  The present invention has been made in view of the above points, and has a motor function and a cooling function for causing the spindle to rotate by the energy of the fluid, and the spindle can be rotated in both forward and reverse rotation directions. An object of the present invention is to provide a spindle device that can control the angle and the number of rotations, and that can be easily operated such as an indexing operation or stopping during rotation.

The spindle device of the present invention according to claim 1 is formed so as to extend in the axial direction at a central portion of the spindle disposed in the casing, and is separated from each other in the intermediate portion. A first fluid supply port and a second fluid supply port independently communicated with each of the first fluid channel and the second fluid channel; the first fluid channel; Fluid is supplied to the first fluid outflow port and the second fluid outflow port, the first fluid supply port, and the second fluid supply port that are independently communicated with each of the second fluid flow paths. A fluid supply means, a first journal bearing and a second journal bearing arranged corresponding to each of the first fluid channel and the second fluid channel of the spindle and supporting a radial position of the spindle; Journal axis And a first thrust bearing and a second thrust bearing that are arranged corresponding to each of the first fluid flow path and the second fluid flow path of the spindle and support an axial position of the spindle. The first fluid outflow port has a first outflow passage having a shape in which the angular momentum of the fluid changes when the fluid flows, and the second fluid outflow port is a fluid. Has a second outflow passage whose shape changes the angular momentum of the fluid, and the first outflow passage and the second outflow passage are mutually connected when the fluid flows. It has a curved shape in which angular momentum changes in different directions .
According to a second aspect of the present invention, in the spindle device according to the first aspect, the first fluid outflow port and the second fluid outflow port are respectively connected to the first fluid flow path and the second fluid outflow port. It is arranged at the end of the fluid flow path.
According to a third aspect of the present invention, in the spindle apparatus according to the first aspect, the fluid supply means makes the flow rates of the fluid supplied to the first fluid supply port and the second fluid supply port independent of each other. It is characterized by controlling.
According to a fourth aspect of the present invention, there is provided the spindle apparatus according to the third aspect , further comprising a rotational speed detecting means for detecting the rotational speed of the spindle, and corresponding to the rotational speed of the spindle detected by the rotational speed detecting means. The flow rate to the first fluid supply port and the second fluid supply port is controlled.
According to a fifth aspect of the present invention, there is provided the spindle apparatus according to the third aspect , further comprising a rotation angle detection unit that detects a rotation angle of the spindle, and according to the rotation angle of the spindle detected by the rotation angle detection unit. The flow rate to the first fluid supply port and the second fluid supply port is controlled.
According to a sixth aspect of the present invention, in the spindle device according to the first aspect, the first journal bearing and the second journal bearing may be configured to press a part of the spindle in a radial direction with a pressurized fluid. It is characterized by comprising a journal hydrostatic bearing 1 and a second journal hydrostatic bearing.
According to a seventh aspect of the present invention, in the spindle device according to the first aspect, the first thrust bearing and the second thrust bearing are pressed in a part of the spindle in the axial direction by a pressurized fluid. It is characterized by comprising one thrust hydrostatic bearing and a second thrust hydrostatic bearing.
According to an eighth aspect of the present invention, in the spindle device according to the seventh aspect , the flow rates of fluids supplied to the first thrust hydrostatic bearing and the second thrust hydrostatic bearing are controlled independently of each other. It is characterized by that.
According to a ninth aspect of the present invention, there is provided the spindle apparatus according to the eighth aspect , further comprising thrust detecting means for detecting a displacement in the axial direction of the spindle according to a displacement amount of the spindle detected by the thrust detecting means. The flow rate to the first thrust hydrostatic bearing and the second thrust hydrostatic bearing is controlled.
A spindle device according to a tenth aspect of the present invention is a fluid supply control system for supplying pressurized fluid to the first journal hydrostatic bearing and the second journal hydrostatic bearing according to claim 6 ; The first thrust hydrostatic bearing and the second thrust hydrostatic bearing according to claim 7 are also used as a fluid supply control system for supplying a pressurized fluid to the first thrust hydrostatic bearing.

According to the present invention, the spindle is driven, supported and cooled by the energy of the fluid, so that no electrical wiring or drive mechanism is required. In addition, the drive, support, and cooling functions can be performed by a mechanism associated with the inside and outside of the spindle rotation shaft, and the center portion of the spindle is hollow, so that the spindle can be reduced in size and weight.
In addition, since the spindle can be rotated in either the forward or reverse rotation direction and the rotation angle and the number of rotations can be controlled, operations such as indexing operation and stopping during rotation can be easily performed.
In addition, since the spindle can be completely non-contact with anything other than the fluid, there is no friction or mechanical play, no seizure even at high speeds, and mechanical vibration transmission elements such as belts and pulleys. unnecessary. Therefore, the rotation operation is smooth and the noise can be reduced.
In addition, by providing a tool such as a diamond tool on the spindle, it is possible to perform ultra-precise machining of a free-form surface by controlling the attitude of the tool by indexing operation and controlling the rotation angle.
Furthermore, since the spindle can be used as an ultra-precision servo motor, positioning of an ultra-precision table used in an ultra-precision machine tool or a liquid crystal panel manufacturing apparatus can be made possible.
Also, when water is used as the fluid, the hydrostatic bearing can be operated in a relatively high rotational speed region because the viscosity coefficient of water is intermediate between air and oil. Further, since water is an incompressible fluid, a higher support rigidity can be obtained as compared with an aerostatic bearing. Therefore, the bearing surface can be reduced.
On the other hand, when air is used as the fluid, the viscosity of the fluid is low, so that the spindle can be rotated at a high speed.

The spindle device according to the first embodiment of the present invention includes a first fluid channel and a second fluid channel that are formed so as to extend in the axial direction at the center portion of the spindle disposed in the casing and separated from each other in the intermediate portion. , A first fluid supply port and a second fluid supply port independently communicated with each of the first fluid channel and the second fluid channel, and the first fluid channel and the first fluid channel. A first fluid outflow port and a second fluid outflow port independently communicated with each of the two fluid flow paths, and a fluid supply means for supplying fluid to the first fluid supply port and the second fluid supply port A first journal bearing and a second journal bearing arranged corresponding to each of the first fluid flow path and the second fluid flow path of the spindle and supporting a radial position of the spindle; 1 fluid flow path Arranged corresponding to each of the preliminary second fluid flow path, and a first thrust bearing and a second thrust bearing for supporting the axial position of the spindle, the first fluid outlet port the fluid The first outflow passage has a shape in which the angular momentum of the fluid changes when flowing, and the second fluid outflow port has a second shape in which the angular momentum of the fluid changes when the fluid flows. It has an outflow channel, and the first outflow channel and the second outflow channel have curved shapes in which the angular momentum changes in different directions when a fluid flows . According to this embodiment, since the spindle has a motor function and a cooling function, a spindle having no mechanical vibration transmission element such as a belt or a pulley and no thermal expansion can be obtained. Also, there is no friction or mechanical backlash necessary for spindle devices used in machine tools that perform high-precision machining, there is no seizure even at high-speed rotation, and mechanical vibration transmission elements such as belts and pulleys. It is possible to satisfy all the conditions without In addition, since two motor parts can be constructed using one spindle, the motor part, thrust hydrostatic bearing and journal hydrostatic bearing are organically integrated, with a small, simple and high-performance construction. It is possible to obtain a spindle device. Further, it is possible to obtain a spindle device that can be rotated in either the forward or reverse rotation direction, can control the rotation angle or the number of rotations, and can perform an operation such as an indexing operation or stopping during rotation. Further, by controlling the flow rate of fluid flowing through the first fluid outflow port and the second fluid outflow port, the rotation direction, rotation speed, and rotation angle of the spindle can be freely controlled.

According to a second embodiment of the present invention, in the spindle device according to the first embodiment, the first fluid outflow port and the second fluid outflow port are respectively connected to the first fluid passage and the second fluid. It is arranged at the end of the flow path. According to the present embodiment, the rotational torque of the spindle can be increased.
According to a third embodiment of the present invention, in the spindle device according to the first embodiment, the fluid supply means makes the flow rates of the fluid supplied to the first fluid supply port and the second fluid supply port independent of each other. Control. According to the present embodiment, the spindle device can be rotated in both forward and reverse rotation directions, and the rotation angle and the number of rotations can be controlled, and an operation such as indexing operation or stopping during rotation is simple. Can be obtained.
According to a fourth embodiment of the present invention, the spindle device according to the third embodiment has a rotation speed detection means for detecting the rotation speed of the spindle, and corresponds to the spindle rotation speed detected by the rotation speed detection means. Thus, the flow rate to the first fluid supply port and the second fluid supply port is controlled. According to the present embodiment, the rotation speed of the spindle can be controlled to a predetermined value.
The fifth embodiment of the present invention has a rotation angle detecting means for detecting the rotation angle of the spindle in the spindle apparatus according to the third embodiment, and according to the number of rotations of the spindle detected by the rotation angle detecting means. Thus, the flow rate to the first fluid supply port and the second fluid supply port is controlled. According to the present embodiment, the rotation angle of the spindle can be controlled to a predetermined value.
According to a sixth embodiment of the present invention, in the spindle device according to the first embodiment, the first journal bearing and the second journal bearing are pressed against a part of the spindle in a radial direction by a pressurized fluid. This is composed of one journal hydrostatic bearing and a second journal hydrostatic bearing. According to this embodiment, stable and highly accurate spindle support by a fluid-controlled journal hydrostatic bearing is possible. That is, there is no friction or mechanical play, and seizure is eliminated even at high speed rotation.
According to a seventh embodiment of the present invention, in the spindle device according to the first embodiment, the first thrust bearing and the second thrust bearing are pressed against a part of the spindle in the axial direction by a pressurized fluid. This is composed of one thrust hydrostatic bearing and a second thrust hydrostatic bearing. According to this embodiment, stable and highly accurate spindle support by a thrust hydrostatic bearing is possible. That is, there is no friction or mechanical play, and seizure is eliminated even at high speed rotation.
In an eighth embodiment of the present invention, in the spindle device according to the seventh embodiment, the flow rates of fluids supplied to the first thrust hydrostatic bearing and the second thrust hydrostatic bearing are controlled independently of each other. It is a configuration. According to this embodiment, the thrust position of the spindle can be easily adjusted by the independently controlled flow rate of the fluid.
The ninth embodiment of the present invention has a thrust detection means for detecting the axial displacement of the spindle in the spindle device according to the eighth embodiment, and corresponds to the amount of spindle displacement detected by the thrust detection means. Thus, the flow rate to the first thrust hydrostatic bearing and the second thrust hydrostatic bearing is controlled. According to the present embodiment, the thrust position can be precisely adjusted in accordance with the displacement of the spindle thrust position.
A spindle apparatus according to a tenth embodiment of the present invention includes a fluid supply control system for supplying pressurized fluid to the first journal hydrostatic bearing and the second journal hydrostatic bearing in the sixth embodiment. In the seventh embodiment, the first thrust hydrostatic bearing and the second thrust hydrostatic bearing are combined with a fluid supply control system for supplying pressurized fluid. According to the present embodiment, the configuration of the fluid supply control system that controls each hydrostatic bearing can be simplified.

Hereinafter, a spindle apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a configuration of a spindle device in Embodiment 1 of the present invention. The spindle 2 in which the motor unit 1 is incorporated includes a pair of journal bearings, that is, a first journal hydrostatic bearing 41 (hereinafter referred to as journal hydrostatic bearing 41) and a second journal hydrostatic bearing 42 (hereinafter referred to as journal hydrostatic bearing). 42) and a pair of thrust bearings, that is, a first thrust hydrostatic bearing 51 (hereinafter referred to as thrust hydrostatic bearing 51) and a second thrust hydrostatic bearing 52 (hereinafter referred to as thrust hydrostatic bearing 52). Supported in the center.
The spindle 2 has a first fluid flow path 21 (hereinafter referred to as a fluid flow path 21) and a second fluid flow path 22 (hereinafter referred to as a flow path) by a pair of axially extending holes separated by a partition wall 10 formed in the center. A fluid flow path 22) is formed, and ends of the fluid flow paths 21 and 22 are plugged with plugs 23 and 24, respectively.
On the outer periphery of the central portion of the spindle 2, a flange portion 11 is formed by extending the side wall of the spindle 2 in the radial direction. The thickness of the flange 11 is slightly larger than the thickness of the partition wall 10.
A fluid such as water supplied from an external pump or compressor (hereinafter abbreviated as “pump”) is fed into the fluid passage 21 of the spindle 2 via a flow rate control device 6 as fluid supply means. A first fluid supply port 25 (hereinafter referred to as “inflow port 25”) for inflow and a first fluid outflow port 26 (hereinafter referred to as “outflow port 26”) for allowing fluid to flow out from the spindle 2 to the outside are formed.
The outflow port 26 is formed inside the fluid flow path 21 with respect to the inflow port 25, that is, at the center of the spindle 2. The fluid flowing in from the inflow port 25 flows along the fluid flow path 21 extending in the axial direction in the spindle 2 and flows out from the outflow port 26. The outflow port 26 is in contact with the partition wall 10 of the spindle 2 and communicates with the outside of the spindle 2 through the flange portion 11.

A sectional view of the outflow port 26 is shown in FIG.
A first outflow channel 31 (hereinafter referred to as an outflow channel 31) extends from the fluid channel 21 formed at the center of the spindle 2 to the outside of the spindle 2. The outflow passage 31 extends from a position in contact with the partition wall 10 of the spindle 2 into the flange portion 11 of the spindle 2 and further communicates with an outflow port 35 opened to the outside of the spindle 2. The outflow channel 31 has a bent shape composed of a narrow tube portion 32 extending in the radial direction from the fluid channel 21 and a path 33 extending substantially perpendicularly from the narrow tube portion 32.
The outflow channel 31 may be formed at one location in the outflow port 26, but it is preferable to provide a plurality of outflow channels 31 in order to increase the rotational speed. FIG. 2A shows a case where four places are provided.
The bending direction of the outflow channel 31 of the outflow port 26 is formed so as to bend counterclockwise from the fluid channel 21 toward the outlet of the outflow channel 31, and the fluid passes through the outflow port 26 from the fluid channel 21. When the fluid flows out, the angular momentum of the fluid changes and the spindle 2 is formed in a shape that rotates clockwise as indicated by an arrow A.
In addition, the angle and shape at which the outflow channel 31 bends is not particularly required to be a right angle or a straight line, and may be any shape that changes the angular momentum of the fluid when the fluid flows into the outflow channel 31. For example, it may be a curved shape extending in the outer peripheral direction of the spindle 2 with an obtuse angle or an arc-shaped smooth curve, and the outflow channel 31 can be formed in the spindle 2 with a simple configuration.
The narrow tube portion 32 is formed by penetrating the fluid flow path 21 in the radial direction from the outer periphery of the spindle 2 toward the center and drilled so as not to penetrate the opposite side of the spindle 2. Then, the path 33 is drilled from the outside of the spindle 2 to communicate with the narrow tube portion 32. Thereafter, the plug 34 is inserted into a hole formed in the outer peripheral surface of the spindle 2 and is plugged so that this portion does not become a flow path.
Similarly, a second fluid supply port 27 (hereinafter referred to as an inflow port 27) that allows fluid to flow into the fluid flow path 22 of the spindle 2 through the flow rate control device 6, and the fluid flow path 22 of the spindle 2, and A second fluid outflow port 28 (hereinafter referred to as an outflow port 28) through which the fluid flows out from the spindle 2 to the outside is formed.
The outflow port 28 is formed inside the fluid flow path 22 with respect to the inflow port 27, that is, at the center of the spindle 2. The fluid flowing in from the inflow port 27 flows along the fluid flow path 22 extending in the axial direction in the spindle 2 and flows out from the outflow port 28. The outflow port 28 is in contact with the partition wall 10 of the spindle 2, and communicates with the outside of the spindle 2 through the flange portion 11.

A cross-sectional view of the outflow port 28 is shown in FIG.
A second outflow passage 36 (hereinafter referred to as an outflow passage 36) extends from the fluid passage 22 formed at the center of the spindle 2 to the outside of the spindle 2. The outflow channel 36 extends from the position in contact with the partition wall 10 of the spindle 2 into the flange portion 11 of the spindle 2, and further communicates with an outflow port 35 opened to the outside of the spindle 2. The outflow channel 36 has a curved shape composed of a narrow tube portion 37 extending in the radial direction from the fluid channel 22 and a path 38 extending substantially perpendicularly from the narrow tube portion 37. Then, the plug 39 is inserted into the hole on the outer peripheral surface of the spindle 2 and stopped.
Further, the outflow passage 36 may be formed at one place in the outflow port 28, but it is preferable to provide a plurality of outflow passages in order to increase the rotational speed. FIG. 2B shows a case where four locations are provided.
The bending direction of the outflow channel 36 of the outflow port 28 is formed to be bent in the direction opposite to that in FIG. 2A, that is, in the clockwise direction from the fluid channel 22 toward the outlet of the outflow channel 36. When the fluid flows out from the fluid flow path 22 through the outflow port 28, the angular momentum of the fluid changes and the spindle 2 rotates in the counterclockwise direction as indicated by the arrow B. .
It should be noted that the angle and shape of the bend of the outflow channel 36 need not be particularly perpendicular or straight like the outflow channel 31, and the angular momentum of the fluid changes when the fluid flows into the outflow channel 36. Any shape is acceptable.

Thrust hydrostatic bearings 51 and 52 for pressing a part of the spindle 2 in the axial direction by pressurized fluid supplied from outside are formed on the outer sides of the outflow ports 26 and 28 in the axial direction of the spindle. The thrust hydrostatic bearings 51 and 52 are disposed outside the flange 11 at the center of the spindle 2 and are made of water or the like supplied to the thrust hydrostatic bearings 51 and 52 from the external pump via the flow rate control device 7. By controlling the amount of fluid, the axial position of the spindle 2 is controlled and supported in the thrust direction. The supplied fluid is discharged from the discharge ports 53 and 54.
On the other hand, journal hydrostatic bearings 41 that radially press a part of the spindle 2 with pressurized fluid supplied from the outside on the inner side in the spindle axial direction on the plugs 23 and 24 side of the fluid flow paths 21 and 22, respectively. 42 is formed.
The journal hydrostatic bearings 41 and 42 supply fluid such as water from the fluid supply ports 43 and 44 from an external pump (not shown) via a flow rate control device (not shown) similar to the flow rate control device 7. The spindle 2 is supported in the journal direction while controlling the radial position of the spindle 2. The supplied fluid is discharged from the discharge ports 45 and 46.
One end of the spindle 2 is provided with a rotary encoder 8 serving as a rotational speed detecting means or rotational angle detecting means for detecting the rotational speed or rotational angle of the spindle 2, and an external flow rate control device via a control circuit 15. 6 is connected.
Further, a position sensor 9 as a thrust detecting means for detecting the position of the spindle 2 in the thrust direction is provided at one end of the spindle 2, and is connected to the flow rate control device 7 through a control circuit 15.
The flow control device 6 is branched into two systems, and flow control valves 61 and 62 are provided in the respective branch paths, and the flow rates of the paths branched into the two systems by the flow control valves 61 and 62 are provided. Can be controlled freely.
On the other hand, the flow control device 7 is branched into two systems, and flow control valves 71 and 72 are provided in the respective branch paths, and each of the paths branched into two systems by the flow control valves 71 and 72 is provided. Can be freely controlled.

Next, the operation will be described.
The fluid supplied from the flow control device 6 is branched into two systems, one flows in from the inflow port 25, flows along the fluid flow path 21 extending in the axial direction in the spindle 2, and flows out from the outflow port 26. To do. Since the fluid flowing out from the outflow port 26 bends out from the narrow tube portion 22 of the outflow passage 31 of the outflow port 26 to the thin tube portion 33, the angular momentum of the fluid changes, and accordingly, the spindle 2 moves in the direction of arrow A. That is, a torque that rotates clockwise is generated and functions as a motor. This motor function can generate torque each time fluid flows out of the outflow passage 31. The rotation of the spindle 2 can be adjusted by the number of outflow channels 31 and the flow rate of the fluid.
On the other hand, the other fluid branched by the flow control device 6 flows from the inflow port 27, flows along the fluid flow path 22 extending in the axial direction in the spindle 2, and flows out from the outflow port 28. Since the fluid flowing out from the outflow port 28 bends out from the narrow tube portion 37 of the outflow passage 36 of the outflow port 28 to the thin tube portion 38, the angular momentum of the fluid changes, and accordingly the spindle 2 moves in the direction of arrow B. That is, torque that rotates counterclockwise is generated and functions as a motor. This motor function can generate torque each time fluid flows out of the outflow passage 36.

When the spindle 2 is to be rotated in the clockwise direction, the flow rate control valve 62 of the flow rate control device 6 is closed and the fluid is not supplied to the inflow port 27 side, but only to the inflow port 25 side by the flow rate control valve 61. Supply fluid. As a result, the fluid is supplied only to the inflow port 25, flows along the fluid flow path 21 extending in the axial direction in the spindle 2, and flows out of the outflow port 26, so that the spindle 2 is supplied to the inflow port 25. It rotates in the clockwise direction at the number of rotations corresponding to the flow rate of.
In order to decrease the rotation speed of the spindle 2, the flow rate control valve 61 of the flow rate control device 6 may be adjusted to reduce the flow rate of the fluid supplied to the inflow port 25. Alternatively, the rotational speed of the spindle 2 can be reduced by opening the flow control valve 62 and supplying the fluid to the inflow port 27. That is, when a fluid is also supplied to the inflow port 27, the fluid supplied to the inflow port 27 flows along the fluid flow path 22 extending in the axial direction in the spindle 2 and flows out from the outflow port 28. Torque is generated to rotate counterclockwise at a rotational speed corresponding to the flow rate of the fluid supplied to the inflow port 27. Therefore, the rotational speed of the spindle 2 rotating in the clockwise direction is reduced under the influence of the torque acting in the counterclockwise direction.
When it is desired to stop the rotation of the spindle 2, the flow rate control valve 61 of the flow rate control device 6 is closed to set the flow rate of the fluid supplied to the inflow port 25 to 0 (zero), or the flow rate control valve 61. 62, the flow rate of the fluid supplied to the inflow port 25 and the inflow port 27 may be the same.
Similarly, when it is desired to rotate the spindle 2 counterclockwise, the flow rate control valve 61 of the flow rate control device 6 is closed and the fluid is not supplied to the inflow port 25 side. The flow rate of the fluid supplied to the inflow port 27 may be made larger than the flow rate of the fluid supplied to the inflow port 25 by adjusting the flow rate control valves 61 and 62 only.

Thus, the spindle 2 tends to rotate in the opposite directions by the fluid supplied from the flow rate control device 6 to each of the fluid flow paths 21 and 22. As a result, the spindle 2 rotates with the rotation direction and the number of rotations changed according to the difference in angular momentum obtained by the fluid supplied to each of the fluid flow paths 21 and 22.
For example, if the angular momentum generated on the fluid flow path 21 side is ω1, the angular momentum generated on the fluid flow path 22 side is ω2, and the absolute value | ω1 | of ω1 is greater than the absolute value | ω2 | The rotation of 2 rotates at a rotational speed determined by the magnitude of the difference of | ω1 | − | ω2 | and rotates in the direction of ω1.
That is, the rotational direction and the rotational speed of the spindle 2 are detected by the rotary encoder 8 and fed back to the flow control device 6 (the flow control valves 61 and 62) via the control circuit 15. By controlling the flow rate of the fluid supplied to the fluid flow path 21 from the flow rate control device 6 and the flow rate of the fluid supplied to the fluid flow path 22, it is possible to control to a predetermined rotation direction and rotation speed.
Also, the rotation angle of the spindle 2 can be controlled. That is, the rotary angle of the spindle 2 is detected by the rotary encoder 8 and fed back to the flow rate control device 6 via the control circuit 15. When the predetermined rotation angle is reached, the fluid flow path 21 and the fluid flow from the flow rate control device 6. When the flow rate of the fluid supplied to the passage 22 is set to 0, the spindle 2 stops rotating at the position at that time. Therefore, the spindle 2 can be controlled to a predetermined rotational angle position. The fine adjustment of the predetermined rotation angle can be performed by adjusting the flow rate control valves 61 and 62 to adjust the flow rate of the fluid supplied from the flow rate control device 6 to the fluid flow path 21 and the fluid flow path 22.

Thus, according to the present embodiment, the spindle 2 can be rotated in either the forward or reverse rotation direction, and the rotation angle and the number of rotations can be controlled. Can be easily performed.
In the above description, the configuration example of the fluid supply unit provided with the two flow control valves 61 and 62 in the flow control device 6 has been described. A configuration may be adopted in which the fluid is supplied to either the fluid channel 21 or the fluid channel 22 by switching the connection using an on-off valve.

On the other hand, the fluid supplied from the flow control device 7 is branched into two systems as described above, one of which is supplied to the thrust hydrostatic bearing 51 via the flow control valve 71 and the other is the flow control valve. The thrust hydrostatic bearing 52 is supplied via 72. The fluid from the flow control device 7 can freely control the flow rate of each of the paths branched into two systems by the flow control valves 71 and 72.
By controlling the amount of fluid supplied from the flow control device 7 to the thrust hydrostatic bearing 51 and the thrust hydrostatic bearing 52 independently from each other by the flow control valves 71 and 72, the axial position of the spindle 2, that is, the thrust The spindle 2 can be supported in the thrust direction by the hydrostatic bearing action of the fluid while independently controlling the thrust position in the direction on the nano-order or sub-micron order. In other words, stable and highly accurate spindle support by the thrust hydrostatic bearing is possible.
Further, the position of the thrust direction is controlled by detecting the position of the spindle 2 in the thrust direction by the position sensor 9 and correspondingly controlling the thrust static by the flow control device 7 (the flow control valves 71 and 72) via the control circuit 15. What is necessary is just to control the flow volume supplied to the pressure bearings 51 and 52. Thereby, the thrust position of the spindle 2 can be precisely adjusted according to the displacement of the thrust position. Then, the fluid supplied to the thrust hydrostatic bearings 51 and 52 is discharged from the discharge ports 53 and 54.
On the other hand, pressurized fluid is supplied from the fluid supply port 43 to the journal hydrostatic bearing 41 and from the fluid supply port 44 to the journal hydrostatic bearing 42 via a flow rate control device (not shown), so that the radial direction of the spindle 2 is increased. The spindle 2 is supported in the journal direction by the hydrostatic bearing action by the fluid while controlling the position. That is, a stable and highly accurate spindle support by a fluid-controlled journal hydrostatic bearing is possible. Then, the fluid supplied to the journal hydrostatic bearings 41 and 42 is discharged from the discharge ports 45 and 46.
A fluid supply control system such as a flow rate control device 7 and a fluid supply pipe for supplying pressurized fluid to the thrust hydrostatic bearings 51 and 52, and a fluid supply control system for supplying pressurized fluid to the journal hydrostatic bearings 41 and 42. It may be configured so as to also serve as a fluid supply control system such as a flow rate control device (not shown) or a fluid supply pipe, thereby simplifying the configuration of the fluid supply control system that controls each hydrostatic bearing. it can.
The fluid supplied to the spindle 2 is optimally water, but other fluids such as air and oil can be used.
Since the fluid flows on the outer periphery and the inside of the spindle 2, the temperature change of the spindle 2 can be made constant by controlling the temperature of the fluid. Therefore, the thermal expansion of the spindle 2 can be minimized, and processing errors caused by the thermal expansion can be eliminated. In addition, the spindle can be cooled.

  As described above, according to the spindle device of the present embodiment, there is no necessary condition for the spindle device used in the machine tool performing high-precision machining, that is, there is no friction or mechanical play, and there is no seizure even at high speed rotation. In addition, all conditions without mechanical vibration transmission elements such as belts and pulleys can be satisfied. In addition, since two motor parts can be constructed using one spindle, the motor part, thrust hydrostatic bearing and journal hydrostatic bearing are organically integrated, with a small, simple and high-performance construction. A spindle device can be obtained. In addition, the spindle device can be rotated in either the forward or reverse direction, the rotation angle and the number of rotations can be controlled, and an operation such as indexing operation or stopping during rotation can be obtained.

In the above description, the example in which the outflow direction of the fluid from the outflow port 26 in the fluid flow path 21 and the outflow direction of the fluid from the outflow port 28 in the fluid flow path 22 are opposite to each other has been described. Both outflow directions can be the same direction. In this case, the rotation of the spindle 2 can be speeded up. This corresponds to a configuration in which two motor units are connected in series.
Further, instead of the hydrostatic bearing using pressurized fluid such as the journal hydrostatic bearings 41 and 42, a ball bearing may be arranged in the space between the casing 5 and the spindle 2 to simplify the structure of the journal bearing. Good.

FIG. 3 is a cross-sectional view showing a configuration of a spindle apparatus according to Embodiment 2 of the present invention. In FIG. 3, the same parts as those in FIG.
In the spindle device of the present embodiment, the outflow ports 26 and 28 are disposed outside the fluid flow paths 21 and 22 with respect to the inflow ports 25 and 27. In addition, flanges 29 and 30 as rotors are formed at both ends of the spindle 2. Thrust hydrostatic bearings 51 and 52 are formed inside the flange portions 29 and 30, and journal hydrostatic bearings 41 and 42 are formed further inside.
The fluid supply passages 77 and 78 to the thrust hydrostatic bearings 51 and 52 and the journal hydrostatic bearings 41 and 42 are branched inside the casing 5, and one fluid supply passage 77 is formed in the thrust hydrostatic bearing 51 and the journal hydrostatic bearing 51. The other fluid supply path 78 is connected to the thrust bearing 41 and the thrust hydrostatic bearing 52 and the journal hydrostatic bearing 42.
The fluid discharged from the outflow ports 26 and 28 and the fluid discharged from the thrust hydrostatic bearings 51 and 52 and the journal hydrostatic bearings 41 and 42 are discharged from the common discharge passages 75 and 76.
A rotary encoder 8 is provided at one end of the spindle 2, and a work holder 82 for holding a workpiece 81 as a processed product is provided at the other end. The outflow ports 26 and 28 have the same configuration as described in FIG.
Since the operation of the present embodiment is essentially the same as that of the first embodiment, description thereof is omitted.
According to the spindle device of the present embodiment, since the flange portions 29 and 30 as rotors having relatively large inertial capacity are formed at both ends of the spindle 2, the spindle 2 can be stably rotated.

FIG. 4 is a cross-sectional view showing a configuration of a spindle apparatus according to Embodiment 3 of the present invention. 4, the same parts as those in FIGS. 1 and 3 are denoted by the same reference numerals, and the description thereof is omitted.
In the spindle apparatus of the present embodiment, in the configuration of the second embodiment, the outflow ports 26 and 28 are formed inside flanges 29 and 30 provided as rotors at both ends of the spindle 2. That is, the outflow ports 26 and 28 are arranged at the ends of the fluid flow paths 21 and 22, respectively. Other configurations and operations are the same as those in the second embodiment.
According to the spindle device of the present embodiment, the length of the fluid flow paths 21 and 22 from the inflow ports 25 and 27 to the outflow ports 26 and 28 can be increased, so that the rotational torque of the flange portions 29 and 30 is increased. can do. Furthermore, the rotational torque of the spindle 2 is increased by increasing the outer moment of the flanges 29 and 30 (that is, the outflow ports 26 and 28) disposed at the ends of the fluid flow paths 21 and 22 to increase the rotational moment. be able to.
Moreover, since the outflow ports 26 and 28 are formed in the flange parts 29 and 30, manufacture is easy. Further, if the flange portions 29 and 30 are detachable from the spindle 2 by a method such as screwing, the shape of the outflow passages 31 and 36 of the outflow ports 26 and 28 can be changed to another shape, and the spindle It is possible to freely change the rotational performance (rotational speed and rotational torque).

  The spindle device according to the present invention can be rotated in both forward and reverse rotation directions, can control the rotation angle and the number of rotations, and can easily perform operations such as indexing operation and stopping during rotation. It has functions that can be used, and is useful as a motor, machine tool, medical device, and the like.

Sectional drawing which shows the structure of the spindle apparatus in Example 1 of this invention. Sectional drawing explaining the internal structure of the outflow port of the spindle apparatus in FIG. Sectional drawing which shows the structure of the spindle apparatus in Example 2 of this invention. Sectional drawing which shows the structure of the spindle apparatus in Example 3 of this invention.

DESCRIPTION OF SYMBOLS 1 Motor part 2 Spindle 5 Casing 6,7 Flow control apparatus 8 Rotary encoder 9 Position sensor 10 Wall 11,29,30 ridge part 15 Control circuit 21,22 Fluid flow path 23,24 Plug 25,27 Inflow port 26,28 Outflow Port 31, 36 Outflow channel 32, 37 Pipe portion 33, 38 Path 34, 39 Plug 35 Outlet 41, 42 Journal hydrostatic bearing 43, 44 Fluid supply port 45, 46 Discharge port 51, 52 Thrust hydrostatic bearing 53, 54 Discharge port 61, 62, 71, 72 Flow control valve 81 Work piece 82 Work holder

Claims (10)

A first fluid channel and a second fluid channel which are formed so as to extend in an axial direction in a central portion of a spindle disposed in the casing and are separated from each other in an intermediate portion; and the first fluid channel and A first fluid supply port and a second fluid supply port communicated independently with each of the second fluid channels; and each of the first fluid channel and the second fluid channel independently. A first fluid outlet port and a second fluid outlet port communicated with each other; a fluid supply means for supplying fluid to the first fluid supply port and the second fluid supply port; and the first of the spindle. A first journal bearing and a second journal bearing disposed corresponding to each of the fluid flow path and the second fluid flow path and supporting a radial position of the spindle; and the first journal bearing of the spindle. Fluid flow path It arranged corresponding to each of the preliminary second fluid flow path, and a first thrust bearing and a second thrust bearing for supporting the axial position of the spindle, said first fluid outlet port Has a first outlet channel whose shape changes the angular momentum of the fluid when the fluid flows, and the second fluid outlet port changes the angular momentum of the fluid when the fluid flows. The first outflow channel and the second outflow channel have curved shapes in which the angular momentum changes in different directions when a fluid flows. A spindle device characterized by that .   The said 1st fluid outflow port and the said 2nd fluid outflow port are arrange | positioned at the edge part of the said 1st fluid flow path and the said 2nd fluid flow path, respectively, The Claim 1 characterized by the above-mentioned. Spindle device.   2. The spindle device according to claim 1, wherein the fluid supply unit controls flow rates of fluids supplied to the first fluid supply port and the second fluid supply port independently of each other. A rotation number detecting means for detecting the number of rotations of the spindle; and depending on the number of rotations of the spindle detected by the rotation number detecting means, the first fluid supply port and the second fluid supply port are supplied to the first fluid supply port and the second fluid supply port. The spindle device according to claim 3 , wherein the flow rate is controlled. A rotation angle detecting means for detecting a rotation angle of the spindle; and depending on the rotation angle of the spindle detected by the rotation angle detection means, the first fluid supply port and the second fluid supply port The spindle device according to claim 3 , wherein the flow rate is controlled.   The first journal bearing and the second journal bearing are constituted by a first journal hydrostatic bearing and a second journal hydrostatic bearing that press a part of the spindle in a radial direction with a pressurized fluid. The spindle device according to claim 1, wherein   The first thrust bearing and the second thrust bearing are constituted by a first thrust hydrostatic bearing and a second thrust hydrostatic bearing that press a part of the spindle in an axial direction with a pressurized fluid. The spindle device according to claim 1, wherein 8. The spindle device according to claim 7 , wherein flow rates of fluids supplied to the first thrust hydrostatic bearing and the second thrust hydrostatic bearing are controlled independently of each other. The first thrust hydrostatic bearing and the second thrust hydrostatic bearing have thrust detecting means for detecting an axial displacement of the spindle, and according to a displacement amount of the spindle detected by the thrust detecting means. The spindle device according to claim 8 , wherein the flow rate to the head is controlled. A fluid supply control system for supplying pressurized fluid to said first journal hydrostatic bearing and said second journal hydrostatic bearing according to claim 6, wherein the first thrust static according to claim 7 A spindle apparatus characterized by combining a pressure bearing and a fluid supply control system for supplying pressurized fluid to the second thrust hydrostatic bearing.

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