Position detection apparatus and motion guide apparatus with position detection apparatus

• US 10,401,198 B2
• Filed: 10/14/2016
• Issued: 09/03/2019
• Est. Priority Date: 10/28/2015
• Status: Active Grant

• Current Assignee: THK Company Limited
• Original Assignee: THK Company Limited
• Inventors: Yamanaka, Shuhei, Moriyuki, Yoshinobu, Oshida, Takashi
• Primary Examiner(s): Bennett, George B
• Application Number:
  US15/772,279
• Publication Number:
  US 20180321060A1
• Time in Patent Office: 1,054 Days
• Field of Search: 33706, 33708
• CPC Class Codes: F16C 2233/00 Monitoring condition, e.g. temperature, load, vibration
• CPC Class Codes: F16C 29/005 Guide rails or tracks for a linear bearing, i.e. adapted for movement of a carriage or bearing body there along
• CPC Class Codes: F16C 29/04 Ball or roller bearings
• CPC Class Codes: F16C 29/0633 with a bearing body defining a U-shaped carriage, i.e. surrounding a guide rail or track on three sides
• CPC Class Codes: F16C 41/00 Other accessories, e.g. devices integrated in the bearing not relating to the bearing function as such
• CPC Class Codes: F16C 41/007 Encoders, e.g. parts with a plurality of alternating magnetic poles
• CPC Class Codes: G01B 7/003 for measuring position, not involving coordinate determination coordinate measuring G01B7/004
• CPC Class Codes: G01D 5/147 influenced by the movement of a third element, the position of Hall device and the source of magnetic field being fixed in respect to each other
• CPC Class Codes: G01D 5/24409 Interpolation using memories
• CPC Class Codes: G01D 5/245 using a variable number of pulses in a train
• CPC Class Codes: G01D 5/2451 Incremental encoders G01D5/2454 takes precedence

Abstract

A position detection apparatus is provided which eliminates the necessity of space to affix a scale to a track member. A track member of a motion guide apparatus is provided with a through hole into which a fastening member to fasten the track member to a base can be inserted. A carriage that is movably assembled to the track member via a rolling element is provided with magnets generating a magnetic field toward the track member. Magnetic sensors that detect a change in the magnetic fields of the magnets with the travel of the magnets relative to the track member are placed within the magnetic fields of the magnets.

Claims

1. A position detection apparatus comprising:

a track member including a through hole where a fastening member to fasten the track member to a base is insertable, to which a carriage is movably assembled via a rolling element;

a magnet generating a magnetic field toward the track member; and

a magnetic sensor placed within the magnetic field, the magnetic sensor being configured to detect a change in the magnetic field of the magnet with the travel of the magnet relative to the track member.

2. The position detection apparatus according to claim 1, wherein the fastening member is a non-magnetic material.

3. The position detection apparatus according to claim 1, wherein the magnetic sensor is placed between the magnet and the track member.

4. The position detection apparatus according to claim 1, wherein the magnet and the magnetic sensor are placed at each end in a travel direction of the carriage in such a manner as to output a Phase A signal and a Phase B signal out of phase with each other by 90 degrees.

5. The position detection apparatus according to claim 1, wherein

two carriages are assembled to the same track member, and

the magnet and the magnetic sensor are assembled to each of the two carriages in such a manner as to output a Phase A signal and a Phase B signal out of phase with each other by 90 degrees.

6. The position detection apparatus according to claim 1, wherein

the track member includes at least two through holes in a length direction of the track member, and

the ratio of a width of a countersink of the through hole to a width of a portion that is not the countersink in a direction of a center line linking the centers of the at least two through holes is set to 1:

x, where 0<

x<

1.

7. A motion guide apparatus with a position detection apparatus comprising:

the position detection apparatus according to claim 1; and

a motion guide apparatus including the track member and the carriage.

8. The position detection apparatus according to claim 2, wherein the magnetic sensor is placed between the magnet and the track member.

9. The position detection apparatus according to claim 2, wherein the magnet and the magnetic sensor are placed at each end in a travel direction of the carriage in such a manner as to output a Phase A signal and a Phase B signal out of phase with each other by 90 degrees.

10. The position detection apparatus according to claim 3, wherein the magnet and the magnetic sensor are placed at each end in a travel direction of the carriage in such a manner as to output a Phase A signal and a Phase B signal out of phase with each other by 90 degrees.

11. The position detection apparatus according to claim 8, wherein the magnet and the magnetic sensor are placed at each end in a travel direction of the carriage in such a manner as to output a Phase A signal and a Phase B signal out of phase with each other by 90 degrees.

12. The position detection apparatus according to claim 2, wherein

two carriages are assembled to the same track member, and

the magnet and the magnetic sensor are assembled to each of the two carriages in such a manner as to output a Phase A signal and a Phase B signal out of phase with each other by 90 degrees.

13. The position detection apparatus according to claim 3, wherein

two carriages are assembled to the same track member, and

the magnet and the magnetic sensor are assembled to each of the two carriages in such a manner as to output a Phase A signal and a Phase B signal out of phase with each other by 90 degrees.

14. The position detection apparatus according to claim 8, wherein

two carriages are assembled to the same track member, and

the magnet and the magnetic sensor are assembled to each of the two carriages in such a manner as to output a Phase A signal and a Phase B signal out of phase with each other by 90 degrees.

15. The position detection apparatus according to claim 2, wherein

the track member includes at least two through holes in a length direction of the track member, and

the ratio of a width of a countersink of the through hole to a width of a portion that is not the countersink in a direction of a center line linking the centers of the at least two through holes is set to 1:

x, where 0<

x<

1.

16. The position detection apparatus according to claim 3, wherein

the track member includes at least two through holes in a length direction of the track member, and

the ratio of a width of a countersink of the through hole to a width of a portion that is not the countersink in a direction of a center line linking the centers of the at least two through holes is set to 1:

x, where 0<

x<

1.

17. The position detection apparatus according to claim 4, wherein

the track member includes at least two through holes in a length direction of the track member, and

the ratio of a width of a countersink of the through hole to a width of a portion that is not the countersink in a direction of a center line linking the centers of the at least two through holes is set to 1:

x, where 0<

x<

1.

18. The position detection apparatus according to claim 5, wherein

the track member includes at least two through holes in a length direction of the track member, and

the ratio of a width of a countersink of the through hole to a width of a portion that is not the countersink in a direction of a center line linking the centers of the at least two through holes is set to 1:

x, where 0<

x<

1.

19. The position detection apparatus according to claim 8, wherein

the track member includes at least two through holes in a length direction of the track member, and

the ratio of a width of a countersink of the through hole to a width of a portion that is not the countersink in a direction of a center line linking the centers of the at least two through holes is set to 1:

x, where 0<

x<

1.

20. The position detection apparatus according to claim 9, wherein

the track member includes at least two through holes in a length direction of the track member, and

the ratio of a width of a countersink of the through hole to a width of a portion that is not the countersink in a direction of a center line linking the centers of the at least two through holes is set to 1:

x, where 0<

x<

1.