JP4076055B2 - Rotary table device with linear motor drive - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to various rotary table devices including a table with an index function (index table) generally used in machine tools and industrial machines and a rotary table used when performing fine processing.
[0002]
[Prior art]
Conventional rotary tables are generally composed of a combination of a servo motor, a worm shaft, and a worm wheel. In such a configuration, the worm shaft and the worm wheel rotate according to the drive of the servo motor, whereby the rotary table installed on the worm wheel rotates.
[0003]
[Problems to be solved by the invention]
However, in the configuration in which the worm shaft and the worm wheel are combined, the backlash is large.
[0004]
Although it is possible to adjust the backlash by using a multi-lead worm, it takes time and effort.
[0005]
Furthermore, the worm shaft and the worm wheel are worn on the tooth surface when used for a long time. Therefore, it was necessary to adjust the backlash repeatedly.
[0006]
An object of the present invention is to provide a rotary table device driven by a linear motor that can perform high-precision indexing and high-speed rotation.
[0007]
[Means for Solving the Problems]
One of the solutions of the present invention comprises a base (20) and a rotary table (30),
A rotary table (30) is set on the base (20) so as to be rotatable about the axis (A),
A hole is formed in the base (20), and a clamp cylinder (38) is provided inside the hole, and the clamp cylinder (38) clamps the rotary table (30) as necessary. Is for
The upper end of the rotary shaft (32) is fixed to the lower surface of the rotary table (30), and the rotary shaft (32) rotates around the axis (A),
A bearing (34) is provided between the rotary table (30) and the base (20), and the rotary table (30) is rotatably supported by the base (20) via the bearing (34). A bearing (36) is also provided between the rotating shaft (32) and the base (20), and the rotating shaft (32) is also rotatably supported by the base (20) via the bearing (36). By providing the plurality of bearings (34, 36), the rotary table (30) is rotatably supported, and swinging is prevented.
A linear motor (40) is set between the rotary table (30) and the base (20), and the linear motor (40) is arranged outside the bearing (34) along the outer periphery of the rotary table (30). It is arranged so that it becomes a large circle as a whole around the axis (A), and is composed of magnets (42, 43) and coils (44, 45), and a rotary table ( 30) is directly driven by its circular linear motor (40),
A magnet support member (46) is attached to the lower surface of the rotary table (30), and the magnet support member (46) is an annular member having a substantially concave cross section with an open inner surface. ) Is fixed to the lower surface of the rotary table (30), the lower part protrudes inward, and magnets (42, 43) are provided on the upper and lower surfaces of the lower part of the magnet support member (46), respectively. The magnets (42, 43) face the coils (44, 45), respectively.
The rotary table device is an indexing table with an index function,
Another solution of the present invention comprises a base (20) and a rotary table (30),
A rotary table (30) is set on the base (20) so as to be rotatable about the axis (A),
A hole is formed in the base (20), and a clamp cylinder (38) is provided inside the hole, and the clamp cylinder (38) clamps the rotary table (30) as necessary. Is for
The upper end of the rotary shaft (32) is fixed to the lower surface of the rotary table (30), and the rotary shaft (32) rotates around the axis (A),
A bearing (34) is provided between the rotary table (30) and the base (20), and the rotary table (30) is rotatably supported by the base (20) via the bearing (34). A bearing (36) is also provided between the rotating shaft (32) and the base (20), and the rotating shaft (32) is also rotatably supported by the base (20) via the bearing (36). By providing the plurality of bearings (34, 36), the rotary table (30) is rotatably supported, and swinging is prevented.
A linear motor (40) is set between the rotary table (30) and the base (20), and the linear motor (40) is arranged outside the bearing (34) along the outer periphery of the rotary table (30). It is arranged so that it becomes a large circle as a whole around the axis (A), and is composed of magnets (42, 43) and coils (44, 45), and a rotary table ( 30) is directly driven by its circular linear motor (40),
A magnet support member (46) is attached to the lower surface of the rotary table (30), and the magnet support member (46) is an annular member having a substantially concave cross section with an open inner surface. ) Is fixed to the lower surface of the rotary table (30), the lower part protrudes inward, and magnets (42, 43) are provided on the upper and lower surfaces of the lower part of the magnet support member (46), respectively. The magnets (42, 43) face the coils (44, 45), respectively.
The rotary table device is a rotary table used when fine processing is performed .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
In the rotary table device according to the present invention, the rotary table is directly driven by a linear motor.
[0009]
While various embodiments are possible, the following are preferred.
[0010]
(1) The rotary table is rotatably supported by the base of the rotary table device via a bearing. Set the magnet of the linear motor on either the rotary table or the base. Set the coil of the linear motor on the other of the rotary table and the base. Both the magnet and coil of the linear motor are located outside the bearing.
[0011]
(2) Both the magnet and coil of the linear motor are circular.
[0012]
(3) The aforementioned rotary table device in which both the magnet and coil of the linear motor are arranged along the outer periphery of the rotary table.
[0013]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0014]
FIG. 1 shows an example of a rotary table device driven by a linear motor according to the present invention.
[0015]
The rotary table device 10 includes a base 20 and a rotary table 30.
[0016]
A rotary table 30 is set on the base 20 so as to be rotatable about an axis A.
[0017]
A cylindrical hole centering on the axis A is formed inside the base 20, and a clamp cylinder 38 is provided on the inner periphery of this hole. The clamp cylinder 38 is for clamping the rotary table 30 as necessary.
[0018]
The upper end of the rotary shaft 32 is fixed to the lower surface of the rotary table 30. The rotary shaft 32 rotates around the axis A, and the upper surface of the rotary table 30 and the rotation center of the rotary shaft 32 are set to be vertical. The rotation shaft 32 rotates around the axis A and coincides with the rotation center of the rotary table 30. That is, the center line of the rotation shaft 32 coincides with the axis A.
[0019]
A ball-type bearing 34 is provided between the rotary table 30 and the base 20. The rotary table 30 is rotatably supported by the base 20 via a ring-shaped bearing 34. A ring-shaped bearing 36 is also provided between the rotary shaft 32 and the base portion 20. The rotating shaft 32 is also rotatably supported by the base 20 via a bearing 36.
[0020]
FIG. 1 shows an example in which the bearings 34 and 36 are configured as a thrust ball bearing and a radial ball bearing, respectively. With the configuration in which the two bearings 34 and 36 are provided, the rotary table 30 is rotatably supported, and swinging is prevented.
[0021]
Although not shown, between the base 20 and the rotary table 30, a scale unit and a detection unit are provided. The rotation number of the rotary table 30 is detected by the scale unit and the detection unit. The detection unit is connected to a control unit (not shown), and the detected signal is sent to the control unit. This control unit controls the rotation and positioning of the rotary table 30 based on the detected signal, a preset program, and the like.
[0022]
A linear motor 40 is set between the rotary table 30 and the base 20. The linear motor 40 is arranged along the outer periphery of the rotary table 30 outside the ring-shaped bearing 34 and has a large ring shape. That is, the linear motor 40 is arranged so as to be a large circle as a whole around the axis A, and is composed of magnets 42 and 43 and coils 44 and 45.
[0023]
The rotary table 30 is directly driven by a circular linear motor 40. For example, coils 44 and 45 are attached to the upper portion of the base 20. The coils 44 and 45 are formed in a planar shape, and are arranged at a predetermined interval in the vertical direction so as to go around the axis A. In addition, the coils 44 and 45 are connected to the control unit so that energization is controlled.
[0024]
A magnet support member 46 is attached to the lower surface of the rotary table 30. The magnet support member 46 is an annular member having a substantially concave cross section with an open inner surface. The upper part of the magnet support member 46 is fixed to the lower surface of the rotary table 30, and the lower part protrudes inward. Magnets 42 and 43 are provided on the lower and upper surfaces of the magnet support member 46, respectively.
[0025]
The magnets 42 and 43 face the coils 44 and 45, respectively.
The arrangement of the magnets 42 and 43 is sequentially different poles in the circumferential direction (in the order of N, S, N...).
[0026]
In the above-described embodiment, the rotary table 30 is controlled by supplying current to the coils 44 and 45 and controlling the attraction and repulsion of the electromagnetic force generated between the magnetic fields generated in the coils 44 and 45 and the magnets 42 and 43. Is rotated in a predetermined direction.
[0027]
【The invention's effect】
According to the first aspect of the present invention, since the rotary table is supported by the bearing and directly driven by the linear motor, there is no swing or backlash, and high accuracy (for example, 0.001 °) is achieved. Both indexing and high-speed rotation can be performed with high accuracy.
[0028]
In addition, this invention is not limited to the above-mentioned Example.
[0029]
The number of coils and magnets is not limited to the above embodiment. One set or three or more sets of coils and magnets may be provided according to the load on the rotary table and the performance of the linear motor.
[0030]
The bearing is not limited to a ball bearing. Various bearings such as a tapered roller bearing can be used in addition to a thrust ball bearing and a radial ball bearing.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a rotary table device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Rotary table apparatus 20 Base 30 Rotary table 32 Rotating shaft 34, 36 Bearing 38 Clamp cylinder 40 Linear motor 42, 43 Magnet 44, 45 Coil 46 Magnet support member

Claims (2)

A base (20) and a rotary table (30);
A rotary table (30) is set at the base (20) so as to be rotatable around the axis (A),
A hole is formed in the base (20), and a clamp cylinder (38) is provided inside the hole. The clamp cylinder (38) clamps the rotary table (30) as necessary. Is for
The upper end of the rotation shaft (32) is fixed to the lower surface of the rotary table (30), and the rotation shaft (32) rotates around the axis (A),
A bearing (34) is provided between the rotary table (30) and the base (20), and the rotary table (30) is rotatably supported by the base (20) via the bearing (34). A bearing (36) is also provided between the rotating shaft (32) and the base (20), and the rotating shaft (32) is also rotatably supported by the base (20) via the bearing (36). By providing the plurality of bearings (34, 36), the rotary table (30) is rotatably supported, and swinging is prevented.
A linear motor (40) is set between the rotary table (30) and the base (20), and the linear motor (40) is arranged outside the bearing (34) along the outer periphery of the rotary table (30). It is arranged so that it becomes a large circle as a whole around the axis (A), and is composed of magnets (42, 43) and coils (44, 45), and a rotary table ( 30) is directly driven by its circular linear motor (40),
A magnet support member (46) is attached to the lower surface of the rotary table (30), and the magnet support member (46) is an annular member having a substantially concave cross section with an open inner surface. ) Is fixed to the lower surface of the rotary table (30), the lower part protrudes inward, and magnets (42, 43) are provided on the upper and lower surfaces of the lower part of the magnet support member (46), respectively. The magnets (42, 43) face the coils (44, 45), respectively.
A rotary table device, wherein the rotary table is an indexing table with an index function. A base (20) and a rotary table (30);
A rotary table (30) is set at the base (20) so as to be rotatable around the axis (A),
A hole is formed in the base (20), and a clamp cylinder (38) is provided inside the hole. The clamp cylinder (38) clamps the rotary table (30) as necessary. Is for
The upper end of the rotation shaft (32) is fixed to the lower surface of the rotary table (30), and the rotation shaft (32) rotates around the axis (A),
A bearing (34) is provided between the rotary table (30) and the base (20), and the rotary table (30) is rotatably supported by the base (20) via the bearing (34). A bearing (36) is also provided between the rotating shaft (32) and the base (20), and the rotating shaft (32) is also rotatably supported by the base (20) via the bearing (36). By providing the plurality of bearings (34, 36), the rotary table (30) is rotatably supported, and swinging is prevented.
A linear motor (40) is set between the rotary table (30) and the base (20), and the linear motor (40) is arranged outside the bearing (34) along the outer periphery of the rotary table (30). It is arranged so that it becomes a large circle as a whole around the axis (A), and is composed of magnets (42, 43) and coils (44, 45), and a rotary table ( 30) is driven directly by its circular linear motor (40). And
A magnet support member (46) is attached to the lower surface of the rotary table (30), and the magnet support member (46) is an annular member having a substantially concave cross section with an open inner surface. ) Is fixed to the lower surface of the rotary table (30), the lower part protrudes inward, and magnets (42, 43) are provided on the upper and lower surfaces of the lower part of the magnet support member (46), respectively. The magnets (42, 43) face the coils (44, 45), respectively.
A rotary table device which is a rotary table used when the rotary table performs fine processing.

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