Wireless sensor, rolling bearing with sensor, management apparatus and monitoring system

• US 20030030565A1
• Filed: 08/06/2002
• Published: 02/13/2003
• Est. Priority Date: 08/07/2001
• Status: Active Grant

• Current Assignee: NSK Limited
• Original Assignee: NSK Limited
• Inventors: Endo, Shigeru, Yanagisawa, Tomoyuki, Takizawa, Takeshi, Sakatani, Ikunori, Shoda, Yoshio, Morita, Kouichi
• Granted Patent: US 7,034,711 B2
• Time in Patent Office: Days
• US Class Current: 340/679
• CPC Class Codes: F16C 19/525 related to temperature and heat, e.g. insulation
• CPC Class Codes: F16C 41/008 Identification means, e.g. markings, RFID-tags; Data transfer means
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01M 13/045 Acoustic or vibration analysis
• CPC Class Codes: G01P 3/443 mounted in bearings bearings F16C
• CPC Class Codes: G01V 1/223 Radioseismic systems

Abstract

The wireless sensor adds identification information peculiar to respective sensor modules to detection data of vibration, temperature, and so on, detected by the sensor modules respectively. The wireless sensor transmits the detection data with the identification information as a signal through a communication unit by radio waves. On the other hand, the management apparatus receiving the signal classifies and files the detection data on the basis of the identification information included in the signal. Then, the monitoring system is designed to make the management apparatus manage a plurality of wireless sensors attached to movable shafts of processing machines or the like.

Claims

1. A wireless sensor for detecting normal condition or abnormality in one of a rolling bearing, a ball screw and a linear guide, comprising:

a detection unit for detecting a subject of detection;

a data processing unit for processing data detected by said detection unit; and

a communication unit for transmitting, by wireless, detection data processed by said processing unit.

2. The wireless sensor according to claim 1, wherein said communication unit transmits, by wireless, said detection data processed by said processing unit together with identification information peculiar to said detection unit.

3. The wireless sensor according to claim 1, wherein said detection unit includes at least one of a vibration sensor for detecting vibration, a temperature sensor for detecting temperature, and a rotation speed sensor for detecting rotation speed.

4. The wireless sensor according to claim 1, wherein said communication unit performs transmission and reception, and when said communication unit receives an instruction signal corresponding to identification information of said detection unit, said communication unit transmits said detection data of said detection unit specified by said instruction signal together with said identification information.

5. The wireless sensor according to claim 1, wherein said communication unit converts at least one of information detected by said detection unit and information involved therein into digital information, and transmits said digital information.

6. A bearing unit with sensor, comprising:

outer and inner rings;

a plurality of rolling elements disposed between said outer and inner rings, wherein one of said outer and inner rings is a stationary ring while the other is a rotating ring; and

said wireless sensor according to claim 1, said wireless sensor being provided on at least one of said stationary ring, a member attached to said stationary ring, said rotating ring and a member attached to said rotating ring.

7. A bearing unit with sensor, comprising:

a pair of first and second raceway rings rotating relatively through rolling elements;

a pulsar ring provided in said first raceway ring; and

said wireless sensor according to claim 3, attached to said second raceway ring rotating relatively to said pulsar ring so as to be opposed to said pulsar ring.

8. The bearing unit with sensor according to claim 7, wherein data about a periodic signal detected by said rotation speed sensor of said wireless sensor is transmitted in an FM modulation in accordance with relative rotation between said pulsar ring and said wireless sensor.

9. The bearing unit with sensor according to claim 7, wherein said communication unit transmits at least one of rotation number and rotation speed of said bearing unit obtained by said data processing unit on a basis of one of a wavelength and a frequency of a periodic signal generated in said rotation speed sensor in accordance with relative rotation between said pulsar ring and said wireless sensor.

10. The bearing unit with sensor according to claim 7, wherein said communication unit transmits at least peculiar identification information at a breakpoint of each period of a periodic signal generated in said rotation speed sensor in accordance with relative rotation between said pulsar ring and said wireless sensor.

17. A monitoring system, comprising:

at least one of said wireless sensor according to claim 1 and said bearing unit according to claim 6;

and

said management apparatus according to claim 11.

18. The monitoring system according to claim 17, wherein at least one of said wireless sensors and at least one of said bearing units are simultaneously used, and

wherein said management apparatus communicates with at least one of said wireless sensors and at least one of said bearing units by carrier waves of peculiar frequencies different from one another.

19. A monitoring system, comprising:

at least one of said wireless sensor according to claim 1 and said bearing unit according to claim 7;

and

said management apparatus according to claim 11.

20. The monitoring system according to claim 19, wherein at least one of said wireless sensors and at least one of said bearing units are simultaneously used, and

wherein said management apparatus communicates with said at least one of wireless sensors and said at least one of bearing units by carrier waves of peculiar frequencies different from one another.

21. A monitoring system, comprising:

at least one of said wireless sensor according to claim 1 and said bearing unit according to claim 6;

and

said management apparatus according to claim 12.

22. The monitoring system according to claim 21, wherein at least one of said wireless sensors and at least one of said bearing units are simultaneously used, and

wherein said management apparatus communicates with at least one of said wireless sensors and at least one of said bearing units by carrier waves of peculiar frequencies different from one another.

23. A monitoring system, comprising:

at least one of said wireless sensor according to claim 1 and said bearing unit according to claim 7;

and

said management apparatus according to claim 12.

24. The monitoring system according to claim 23, wherein at least one of said wireless sensors and at least one of said bearing units are simultaneously used, and

wherein said management apparatus communicates with said at least one of wireless sensors and said at least one of bearing units by carrier waves of peculiar frequencies different from one another.

25. A monitoring system, comprising:

at least one of said wireless sensor according to claim 1 and said bearing unit according to claim 6;

and

said management apparatus according to claim 13.

26. The monitoring system according to claim 25, wherein at least one of said wireless sensors and at least one of said bearing units are simultaneously used, and

wherein said management apparatus communicates with at least one of said wireless sensors and at least one of said bearing units by carrier waves of peculiar frequencies different from one another.

27. A monitoring system, comprising:

at least one of said wireless sensor according to claim 1 and said bearing unit according to claim 7;

and

said management apparatus according to claim 13.

28. The monitoring system according to claim 27, wherein at least one of said wireless sensors and at least one of said bearing units are simultaneously used, and

wherein said management apparatus communicates with said at least one of wireless sensors and said at least one of bearing units by carrier waves of peculiar frequencies different from one another.

11. A management apparatus, comprising:

a communication tool for receiving a signal transmitted from one of a wireless sensor and a bearing unit having a detection unit for detecting a subject of detection; and

a signal processing unit for managing said received signal on a basis of identification information peculiar to at least one of said detection unit, said wireless sensor and said bearing unit, said identification information being included in said signal.

14. The management apparatus according to claim 11, wherein said management apparatus communicates with said wireless sensor and said bearing unit by digital signals.

12. A management apparatus, comprising:

a communication unit for selectively receiving a signal transmitted from one of a wireless sensor and a bearing unit having a detection unit for detecting a subject of detection in accordance with identification information peculiar to said detection unit included in said signal, said selectively received signal including identification information registered in advance in said management apparatus.

15. The management apparatus according to claim 12, wherein said management apparatus communicates with said wireless sensor and said bearing unit by digital signals.

13. A management apparatus, comprising:

a communication unit for receiving a signal transmitted from one of a wireless sensor and a bearing unit, and transmitting an instruction signal to make a request to one of said wireless sensor and said bearing unit for receiving said signal.

16. The management apparatus according to claim 13, wherein said management apparatus communicates with said wireless sensor and said bearing unit by digital signals.

29. A rolling bearing with sensor, comprising:

an outer ring and an inner ring which can rotate relatively to each other, one of said outer and inner rings being a stationary ring while the other is a rotating ring;

a plurality of rolling elements incorporated between said outer ring and said inner ring; and

a detection sensor unit provided in at least one of said stationary ring, a member attached to said stationary ring, said rotating ring and a member attached to said rotating ring, said detection sensor unit detecting a condition of said rolling bearing;

wherein said detection sensor unit has a communication function for transmitting data to outside by wireless.

30. The rolling bearing with sensor according to claim 29, wherein said detection sensor unit has a communication function for receiving data from outside by wireless.

31. The rolling bearing with sensor according to claim 30, further comprising:

at least one relay unit being transmittable detection data detected by said detection sensor unit to outside by wireless.

32. The rolling bearing with sensor according to claim 31, said relay unit including:

a communication unit converting said detection data from said detection sensor unit into a signal wave with a predetermined frequency component and transmitting said signal wave to outside by wireless.

33. The rolling bearing with sensor according to claim 31, wherein said detection sensor unit and said relay unit are electrically connected through a cable, and said detection data from said detection sensor unit is transmitted to said relay unit through said cable.

34. The rolling bearing with sensor according to claim 31, said detection sensor unit including:

a communication unit converting said detection data of said detection sensor unit into a signal wave with a predetermined frequency component and transmitting said signal wave to said relay unit by wireless.

35. The rolling bearing with sensor according to claim 31, wherein said signal wave is one of a radio wave, a light wave and an ultrasonic wave with a predetermined frequency component.

36. The rolling bearing with sensor according to claim 34, wherein said signal wave is one of a radio wave, a light wave and an ultrasonic wave with a predetermined frequency component.

37. The rolling bearing with sensor according to claim 31, wherein said detection sensor unit and said relay unit are electrically connected by use of electromagnetic induction,

wherein said detection sensor unit has a modulation circuit for modulating said detection data of said detection sensor unit into a predetermined modulated signal, and wherein said relay unit has a demodulation circuit for demodulating said modulated signal.

38. The rolling bearing with sensor according to claim 30, wherein said detection sensor unit includes at least one of a vibration sensor, a temperature sensor, a rotation speed sensor and a pressure sensor.

39. The rolling bearing with sensor according to claim 31, wherein signals from a plurality of detection sensor units having identification numbers respectively are relayed by relay units the number of which is smaller than the number of said detection sensor units.

40. The rolling bearing with sensor according to claim 30, wherein said detection sensor unit has an acoustic detection sensor for detecting vibration condition of said rolling bearing, and

where in detection data detected by said acoustic detection sensor is transmitted to outside by wireless.

41. The rolling bearing with sensor according to claim 40, wherein said acoustic detection sensor transduces a vibration wave generated mechanically into an electric signal.

42. The rolling bearing with sensor according to claim 40, wherein said acoustic detection sensor is set to be incorporated in a sensor holder, and

wherein an amplification circuit for amplifying an output of said acoustic detection sensor is provided within said sensor holder.

43. The rolling bearing with sensor according to claim 42, further comprising:

a comparator for comparing said output of said acoustic detection sensor with a reference value; and

a counter for counting number of times of said output of said acoustic detection sensor exceeding said reference value within a predetermined time, said comparator and said counter being provided within said sensor holder.

44. The rolling bearing with sensor according to claim 42, further comprising:

a transmission circuit converting said output of said acoustic detection sensor in to a signal wave with a predetermined frequency component and transmitting said signal wave to outside, said transmission circuit being provided within said sensor holder.

45. A rolling bearing with sensor according to claim 44, wherein said signal wave is one of a radio wave, a light wave and an ultrasonic wave with a predetermined frequency component.

46. A bearing unit with sensor comprising:

a rolling bearing having at least an outer ring, an inner ring and a plurality of rolling elements, at least one of said outer and inner rings being a rotating ring while the other is a stationary ring;

an integral-type sensor having at least one sensor for detecting a condition of said bearing unit and a single sensor holder for including said sensor, said integral-type sensor being attached to one of said stationary ring and a member attached to said stationary ring; and

at least one relay unit provided in the vicinity of one of said integral-type sensor and said bearing, said relay unit transmitting an output signal from said integral-type sensor to a control unit provided outside said bearing unit.

47. The bearing unit with sensor according to claim 46, wherein said relay unit transmits said output signal from said integral-type sensor to said control unit after amplifying said output signal.

48. The bearing unit with sensor according to claim 46, wherein said relay unit transmits said output signal from said integral-type sensor to said control unit after converting said output signal into a signal suitable for long distance transmission.

49. The bearing unit with sensor according to claim 46, wherein said sensor for detecting the condition of said bearing unit includes at least one of a rotation speed sensor, a temperature sensor and a vibration sensor.

50. The bearing unit with sensor according to claim 46, wherein said signal from said relay unit is extracted from said bearing unit to outside by use of a cable.

51. The bearing unit with sensor according to claim 46, wherein said signal from said relay unit is extracted from said bearing unit to outside by wireless.

52. A rolling bearing with sensor, comprising:

an outer ring and an inner ring which can rotate relatively to each other, one of said outer and inner rings being a stationary ring while the other is a rotating ring;

a plurality of rolling elements incorporated between said outer ring and said inner ring;

at least one sensor provided in at least one of said stationary ring, a member attached to said stationary ring, said rotating ring and a member attached to said rotating ring; and

a board on which said at least one sensor is mounted,

wherein said board is fixed to said sensor holder by screwing.

53. The bearing unit with sensor according to claim 52, wherein said sensor includes at least one of a vibration sensor for measuring a vibration condition of said rolling bearing, a rotation speed sensor for measuring a rotation speed of said rolling bearing and a temperature sensor for measuring a temperature of said rolling bearing.

54. The bearing unit with sensor according to claim 52, wherein said sensor is incorporated in a single sensor bolder together with electronic elements for driving said sensor, and said sensor and said electronic elements are mounted on a predetermined board.

55. The bearing unit with sensor according to claim 52, further comprising:

an amplification circuit for amplifying an output of said sensor.

56. A rolling bearing with sensor, comprising:

an outer ring and an inner ring which can rotate relatively to each other, one of said outer and inner rings being a stationary ring while the other is a rotating ring;

a plurality of rolling elements incorporated between said outer ring and said inner ring; and

at least one sensor provided in at least one of said stationary ring, a member attached to said stationary ring, said rotating ring and a member attached to said rotating ring;

an electronic clement for driving said sensor; and

a board on which said sensor and said electronic element are mounted,

wherein a portion of said board mounted with said sensor and said electronic element is surrounded by at least one of flexible silicon rubber and foaming rubber, and then molded with hard molding resin.

57. The bearing unit with sensor according to claim 56, wherein said sensor includes at least one of a vibration sensor for measuring a vibration condition of said rolling bearing, a rotation speed sensor for measuring a rotation speed of said rolling bearing and a temperature sensor for measuring a temperature of said rolling bearing.

58. The bearing unit with sensor according to claim 56, further comprising:

an amplification circuit for amplifying an output of said sensor.

59. A rolling bearing with sensor, comprising:

an outer ring and an inner ring which can rotate relatively to each other, one of said outer and inner rings being a stationary ring while the other is a rotating ring;

a plurality of rolling elements incorporated between said outer ring and said inner ring; and

at least one sensor provided in at least one of said stationary ring, a member attached to said stationary ring, said rotating ring and a member attached to said rotating ring, said sensor measuring at least vibration condition of said rolling bearing;

wherein said sensor includes a bi-morpheme piezoelectric element having a double end support structure.

60. The bearing unit with sensor according to claim 59, wherein said sensor includes at least one of a rotation speed sensor for measuring rotation speed of said rolling bearing and a temperature sensor for measuring temperature of said rolling bearing.

61. The bearing unit with sensor according to claim 59, wherein said sensor is incorporated in a single sensor holder together with electronic elements for driving said sensor, and said sensor and said electronic elements are mounted on a predetermined board.

62. The bearing unit with sensor according to claim 59, further comprising:

an amplification circuit for amplifying an output of said sensor.