WO2023219050A1 - Dispositif de capteur - Google Patents

Dispositif de capteur Download PDF

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Publication number
WO2023219050A1
WO2023219050A1 PCT/JP2023/017223 JP2023017223W WO2023219050A1 WO 2023219050 A1 WO2023219050 A1 WO 2023219050A1 JP 2023017223 W JP2023017223 W JP 2023017223W WO 2023219050 A1 WO2023219050 A1 WO 2023219050A1
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WO
WIPO (PCT)
Prior art keywords
bearing
holder
sensor device
strain gauge
shaft
Prior art date
Application number
PCT/JP2023/017223
Other languages
English (en)
Japanese (ja)
Inventor
裕昭 村上
幸嗣 癸生川
Original Assignee
ミネベアミツミ株式会社
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Filing date
Publication date
Application filed by ミネベアミツミ株式会社 filed Critical ミネベアミツミ株式会社
Publication of WO2023219050A1 publication Critical patent/WO2023219050A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C35/00—Rigid support of bearing units; Housings, e.g. caps, covers
    • F16C35/04—Rigid support of bearing units; Housings, e.g. caps, covers in the case of ball or roller bearings
    • F16C35/06—Mounting or dismounting of ball or roller bearings; Fixing them onto shaft or in housing
    • F16C35/067—Fixing them in a housing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C41/00—Other accessories, e.g. devices integrated in the bearing not relating to the bearing function as such
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B5/00—Measuring arrangements characterised by the use of mechanical techniques
    • G01B5/24—Measuring arrangements characterised by the use of mechanical techniques for measuring angles or tapers; for testing the alignment of axes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/16—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/30—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes

Definitions

  • the present invention relates to a sensor device.
  • Optical sensor devices and magnetic sensor devices are known as sensor devices for detecting the rotation angle of a rotating body.
  • An optical sensor device is disclosed in Patent Document 1, for example.
  • a magnetic sensor device is disclosed in Patent Document 2, for example.
  • Optical sensor devices and magnetic sensor devices are easily affected by the environment, such as contamination by dust and surrounding magnetism, so there is a need for sensor devices with higher environmental resistance.
  • An example of the present invention is to provide a sensor device with excellent environmental resistance.
  • the sensor device of the present invention includes a shaft, a bearing having an inner circumferential side and an outer circumferential side, and a strain gauge attached to the outer circumferential side of the bearing directly or via another member.
  • the shaft is disposed inside the inner peripheral side of the bearing, and the bearing and the shaft are eccentric with respect to each other.
  • FIG. 1 is a sectional view of a sensor device according to a first embodiment, which is an example of the present invention.
  • FIG. 1 is a plan view of a sensor device according to a first embodiment, which is an example of the present invention.
  • FIG. 3 is a sectional view of a sensor device according to a second embodiment, which is an example of the present invention.
  • FIG. 7 is a plan view of a sensor device according to a second embodiment, which is an example of the present invention.
  • FIG. 7 is a sectional view of a sensor device according to a third embodiment, which is an example of the present invention.
  • FIG. 7 is a cross-sectional view of a sensor device according to a fourth embodiment, which is an example of the present invention.
  • FIG. 1 is a plan view of a sensor device according to a first embodiment, which is an example of the present invention.
  • FIG. 3 is a sectional view of a sensor device according to a second embodiment, which is an example of the present invention.
  • FIG. 7 is a perspective view of a holder and a strain gauge of a sensor device according to a fifth embodiment, which is an example of the present invention.
  • FIG. 7 is a sectional view of a sensor device according to a fifth embodiment, which is an example of the present invention.
  • the direction of arrow a along the axis X (the central axis of the shaft S) is referred to as the upper side or one side in the axial direction.
  • the direction of arrow b along axis X is defined as the lower side or the other axial side.
  • the direction of arrow ab is referred to as an up-down direction or an axial direction.
  • the vertical direction does not necessarily match the vertical direction.
  • the direction of the arrow cd is referred to as the radial direction
  • the direction of the arrow c away from the axis X is referred to as the outer side or one side in the radial direction
  • the direction of the arrow d approaching the axis X is referred to as the inner side or the other side in the radial direction
  • the direction along the tangent of the circle around the axis X is referred to as the tangential direction.
  • FIG. 1 is a cross-sectional view of a sensor device 100 according to this embodiment.
  • FIG. 2 is a plan view of the sensor device 100.
  • the sensor device 100 includes a shaft S, a bearing 101 having an inner circumferential side 101a and an outer circumferential side 101b, and a strain gauge 102 attached to the outer circumferential side 101b of the bearing 101 via a holder 104.
  • the bearing 101 is a ball bearing having an inner ring 101i, an outer ring 101o, and rolling elements. Note that the bearing 101 is not limited to a ball bearing, and may be various other bearings such as a sleeve bearing.
  • the shaft S is a cylindrical member extending in the axial direction. As shown in FIGS. 1 and 2, in the radial direction, the shaft S is disposed inside the inner peripheral side 101a of the bearing 101 (the other radial side, in the direction of arrow d). In the axial direction, the lower end (the other axial side, the direction of arrow b) of the shaft S projects from the through hole 11 of the external device 10 to the outside of the external device 10 .
  • An eccentric member 103 whose axial dimension is the same or substantially the same as that of the bearing 101 is arranged between the inner peripheral side 101a of the bearing 101 and the shaft S. The eccentric member 103 makes the bearing 101 and the shaft S eccentric to each other. In other words, the eccentric member 103 makes the bearing 101 eccentric with respect to the shaft S.
  • the eccentric member 103 is a cylindrical member extending in the axial direction, and has a cylindrical through hole having an inner diameter that is the same or substantially the same as the outer diameter (diameter) of the shaft S. That is, the eccentric member 103 is an annular member. In the eccentric member 103, the central axis of the outer circumferential surface (the radially outer surface (radially one side, direction of arrow c)) and the center axis of the inner circumferential surface (radially inner surface) do not coincide. Therefore, the eccentric member 103 has a maximum thickness portion 103a having the maximum thickness in the radial direction and a minimum thickness portion 103b having the minimum thickness in the radial direction.
  • the shaft S is bonded or press-fitted to the inner circumferential surface (radially inner surface) of the eccentric member 103. Thereby, the shaft S is fixed integrally with the eccentric member 103.
  • the inner ring 101i of the bearing 101 is bonded or press-fitted to the outer peripheral surface (radially outer surface) of the eccentric member 103. Thereby, the inner ring 101i of the bearing 101 is fixed to the eccentric member 103.
  • the axis X which is the central axis of the shaft S, is shifted from the central axis Y of the eccentric member 103 and the bearing 101, so that the bearing 101 and the shaft S have an eccentric positional relationship with respect to each other.
  • each holder 104 In the radial direction, on the outside of the bearing 101, there are four holders 104 that are approximately L-shaped in side view and are arranged at positions that overlap when rotated by 90 degrees around the axis X and have rotational symmetry (hereinafter referred to as "4-fold symmetry"). is located. Each holder 104 is in contact with the outer peripheral side 101b of the bearing 101. In this way, each holder 104 holds a bearing 101.
  • the bearing 101 is arranged above (on one side in the axial direction, in the direction of arrow a) than a fixing part 143, which will be described later.
  • Each holder 104 holds a strain gauge 102. That is, the sensor device 100 has a first strain gauge 102a held in a first holder 104a, a second strain gauge 102b held in a second holder 104b, and a third holder 104c in a clockwise direction when viewed from above. It has a total of four strain gauges 102, including a third strain gauge 102c held (hidden in FIG. 2) and a fourth strain gauge 102d held in a fourth holder 104d.
  • Two strain gauges 102 adjacent in the circumferential direction are arranged at symmetrical positions with respect to a certain plane containing the axis X.
  • the angle between the direction from the axis X toward the first strain gauge 102a and the direction from the axis X toward the second strain gauge 102b is 90 degrees. Since all four holders 104 have the same configuration, only one holder 104 will be described in detail hereafter, and detailed description of the other holders 104 will be omitted unless necessary.
  • the holder 104 includes a rectangular plate portion 141 extending in the axial direction, and a rectangular plate portion 141 extending radially outward from the lower end of the plate portion 141 in the axial direction. It has a fixed part 143 having a shape. In the radial direction, a recess 144 that is semicircular in side view and extends in the tangential direction is formed on the inner surface of the plate portion 141 . The recessed portion 144 is formed in the plate portion 141 slightly downward from the center in the axial direction.
  • the wall thickness of the portion where the recessed portion 144 is formed is thinner, and becomes an elastic portion 142 that can undergo elastic strain deformation.
  • Strain gauge 102 is attached to the radially outer surface of elastic portion 142 . Strain deformation of the elastic portion 142 can be detected as a change in the resistance value of the strain gauge 102.
  • the outer peripheral side 101b of the bearing 101 is in contact with the axially inner surface of the plate portion 141 at a portion above the recess 144.
  • the strain gauge 102 is installed so as to be able to detect strain in the elastic portion 142 in a direction along a plane perpendicular to the tangential direction. That is, the strain gauge 102 is attached to the elastic portion 142 such that the grid orientation (typically, the longitudinal direction of the strain gauge) is in the axial direction.
  • a circular through hole 143h is formed near the center of the fixing part 143 of the holder 104.
  • the holder 104 is fixed to the external device 10 via a spacer 106 by a bolt 105 inserted into the through hole 143h.
  • the maximum thickness portion 103a of the eccentric member 103 is located close to the third holder 104c, and the minimum thickness portion 103b of the eccentric member 103 is located close to the first holder 104a. Therefore, the plate portion 141 of the third holder 104c is pressed radially outward by the bearing 101. Note that the respective plate portions 141 of the second holder 104b and the fourth holder 104d adjacent to the third holder 104c are also slightly pressed radially outward by the bearing 101.
  • the elastic portion 142 of the third holder 104c has undergone the largest strain deformation, and the upper side of the plate portion 141 in the axial direction is warped toward the outside in the radial direction. ing.
  • the elastic portions 142 of the second holder 104b and the fourth holder 104d adjacent to the third holder 104c are in a slightly strained state.
  • the elastic portion 142 of the first holder 104a is in a state where it is least strained or not strained at all.
  • the eccentric member 103 fixed to the shaft S also rotates, and the central axis Y of the bearing 101 also rotates around the axis X accordingly.
  • the central axis Y of the bearing 101 rotates around the axis X in a clockwise direction in a plan view.
  • the elastic portion 142 of the fourth holder 104d transitions to a state in which it is most strained. .
  • the bearing 101 and the shaft S are attached eccentrically to each other.
  • the inner ring 101i of the bearing 101 rotates eccentrically with respect to the shaft S, and the rotation angle can be detected by the strain gauge 102 attached to the outer peripheral side 101b of the bearing 101 via the holder 104. ing. Since the sensor device 100 according to the present embodiment does not use an optical or magnetic sensor, it is hardly affected by contamination by dust or the like or by surrounding magnetism. Therefore, the sensor device 100 according to this embodiment has excellent environmental resistance.
  • the eccentric member 103 of the sensor device 100 according to the present embodiment is an annular member, it has excellent strength and has a long life compared to a case where a wedge or the like is used. Further, the sensor device 100 according to the present embodiment has a plurality of strain gauges 102 including a first strain gauge 102a and a second strain gauge 102b, and the first strain gauge 102a and the second strain gauge 102b is arranged at a symmetrical position with respect to a plane containing the central axis (axis The angle formed by the direction toward is 90°. Therefore, the sensor device 100 according to this embodiment can detect the rotation angle of the shaft S with higher accuracy.
  • FIG. 3 is a cross-sectional view of sensor device 200 according to this embodiment.
  • FIG. 4 is a plan view of the sensor device 200.
  • the sensor device 200 has the same configuration as the sensor device 100 according to the first embodiment, except that it includes a holder 204 instead of the holder 104.
  • members and components having the same functions and configurations as those in the first embodiment will be designated by the same reference numerals as in the first embodiment, and detailed description thereof will be omitted.
  • the sensor device 200 includes a shaft S, a bearing 101 having an inner circumferential side 101a and an outer circumferential side 101b, and a strain gauge 102 attached to the outer circumferential side 101b of the bearing 101 via a holder 204.
  • annular holder 204 having an L-shape in cross section is arranged outside the bearing 101.
  • the holder 204 is in contact with the outer peripheral side 101b of the bearing 101. In this way, the holder 204 holds the bearing 101.
  • the bearing 101 is arranged above a fixed portion 243, which will be described later, in the axial direction.
  • the holder 204 holds the four strain gauges 102 at four-fold symmetrical positions around the axis X in an unstrained state. That is, the sensor device 200 includes, in clockwise plan view, a first strain gauge 102a, a second strain gauge 102b, a third strain gauge 102c (hidden in FIG. 4), and a fourth strain gauge 102d. It has four strain gauges 102.
  • Two strain gauges 102 adjacent in the circumferential direction are arranged at symmetrical positions with respect to a plane containing the axis X.
  • the angle between the direction from the axis X toward the first strain gauge 102a and the direction from the axis X toward the second strain gauge 102b is 90 degrees.
  • the holder 204 includes a cylindrical portion 241 that extends in the axial direction, and four plate-shaped plates that are rectangular in plan view and extend radially outward from the lower end of the cylindrical portion 241 in the axial direction. It has a fixed part 243.
  • the four fixing parts 243 are arranged at four-fold symmetrical positions around the axis X.
  • an annular recess 244 having a semicircular cross section is formed on the inner circumferential surface (radially inner surface) 241a of the cylindrical portion 241.
  • the recess 244 is formed in the cylindrical portion 241 slightly downward from the axial center.
  • the portion where the recess 244 is formed has a thinner wall thickness, and is an elastic portion 242 that can undergo elastic strain deformation.
  • Strain gauge 102 is attached to the radially outer surface of elastic portion 242 . Strain deformation of the elastic portion 242 can be detected as a change in the resistance value of the strain gauge 102.
  • the outer circumferential side 101b of the bearing 101 is in contact with the inner circumferential surface 241a of the cylindrical portion 241 at a portion above the position where the strain gauge 102 is attached.
  • the strain gauge 102 is installed so that it can detect strain in the elastic portion 242 in a direction along a plane perpendicular to the tangential direction. That is, the strain gauge 102 is attached to the elastic portion 242 such that the grid orientation (typically, the longitudinal direction of the strain gauge) is in the axial direction.
  • a circular through hole 243h is formed near the center of the fixing part 243 of the holder 204.
  • the holder 204 is fixed to the external device 10 via the spacer 106 by a bolt 105 inserted into the through hole 243h.
  • the maximum thickness portion 103a of the eccentric member 103 is located close to the third strain gauge 102c, and the minimum thickness portion 103b of the eccentric member 103 is located close to the first strain gauge 102a. . Therefore, the cylindrical portion 241 of the holder 204 is pressed radially outward by the bearing 101 on the side where the third strain gauge 102c is attached. Note that the side of the cylindrical portion 241 of the holder 204 to which the second strain gauge 102b and the fourth strain gauge 102d are attached is also slightly pressed radially outward by the bearing 101.
  • the side of the elastic portion 242 of the holder 204 to which the third strain gauge 102c is attached is subjected to the largest strain deformation, and the axially upper side of the cylindrical portion 241 is radially outward. It is in a state where it is curved towards.
  • the side of the elastic portion 242 of the holder 204 to which the second strain gauge 102b and the fourth strain gauge 102d are attached is in a slightly deformed state.
  • the side of the elastic portion 242 of the holder 204 to which the first strain gauge 102a is attached is in a state where it is least strain-deformed.
  • the eccentric member 103 fixed to the shaft S also rotates, and the central axis Y of the bearing 101 also rotates around the axis X accordingly.
  • the central axis Y of the bearing 101 rotates around the axis X in a clockwise direction in a plan view.
  • the central axis Y of the bearing 101 rotates 90° clockwise in plan view from the state shown in FIG. Transition to the state where
  • the elastic portion 242 of the holder 204 sequentially The side to which the third strain gauge 102c is attached, the side to which the fourth strain gauge 102d is attached, the side to which the first strain gauge 102a is attached, and the side to which the second strain gauge 102b is attached have the highest strain. Transition to a transformed state. Therefore, the rotation angle of the shaft S can be detected by the four strain gauges 102 attached to the holder 204.
  • the sensor device 200 according to the present embodiment similarly has the characteristics described above for the sensor device 100 according to the first embodiment.
  • the holder 204 is composed of one member, so it is superior in strength, the strain gauge 102 can be easily positioned, and the sensor device 200 can be easily attached to an external device. It's easy.
  • FIG. 5 is a cross-sectional view of sensor device 300 according to this embodiment.
  • the sensor device 300 has the same configuration as the sensor device 100 according to the first embodiment, except that an eccentric member 303 is provided instead of the eccentric member 103.
  • members and components having the same functions and configurations as those in the first embodiment will be designated by the same reference numerals as in the first embodiment, and detailed description thereof will be omitted.
  • An eccentric member 303 is arranged between the inner peripheral side 101a of the bearing 101 and the shaft S.
  • the eccentric member 303 makes the bearing 101 and the shaft S eccentric to each other.
  • the eccentric member 303 makes the bearing 101 eccentric with respect to the shaft S.
  • the eccentric member 303 is a wedge having a substantially right triangular shape in cross section.
  • the eccentric member 303 has a shape in which the radial dimension becomes smaller toward the lower side, and in the axial direction, the eccentric member 303 is inserted from the upper side of the bearing 101 toward the lower side. .
  • the eccentric member 303 has a shape in which the radial dimension becomes smaller as it goes upward; It may be inserted.
  • the radially inner surface of the eccentric member 303 is bonded or press-fitted to the outer circumferential surface (radially outer surface) of the shaft S. Thereby, the eccentric member 303 is integrally fixed to the shaft S.
  • the inner ring 101i of the bearing 101 is bonded or press-fitted to the radially outer surface of the eccentric member 303. Thereby, the inner ring 101i of the bearing 101 is fixed to the eccentric member 303.
  • the eccentric member 303 is located close to the third holder 104c. Therefore, the plate portion 141 of the third holder 104c is pressed radially outward by the bearing 101. Note that the respective plate portions 141 of the second holder 104b and the fourth holder 104d adjacent to the third holder 104c are also slightly pressed radially outward by the bearing 101.
  • the elastic portion 142 of the third holder 104c has undergone the largest strain deformation, and the axially upper side of the plate portion 141 is warped radially outward.
  • the elastic portions 142 of the second holder 104b and the fourth holder 104d adjacent to the third holder 104c are in a slightly strained state.
  • the elastic portion 142 of the first holder 104a is in a state where it is least strained or not strained at all.
  • the eccentric member 303 fixed to the shaft S also rotates, and the central axis Y of the bearing 101 also rotates around the axis X accordingly.
  • the central axis Y of the bearing 101 rotates around the axis X in a clockwise direction in a plan view.
  • the elastic portion 142 of the fourth holder 104d transitions to a state in which it is most strained.
  • the sensor device 300 according to the present embodiment similarly has the characteristics described above for the sensor device 100 according to the first embodiment.
  • the sensor device 300 according to this embodiment is lightweight because the eccentric member 303 is a wedge.
  • FIG. 6 is a cross-sectional view of sensor device 400 according to this embodiment.
  • the sensor device 400 has the same configuration as the sensor device 100 according to the first embodiment, except that it includes a holder 404 instead of the holder 104.
  • members and components having the same functions and configurations as those in the first embodiment will be designated by the same reference numerals as in the first embodiment, and detailed description thereof will be omitted.
  • the sensor device 400 includes a shaft S, a bearing 101 having an inner circumferential side 101a and an outer circumferential side 101b, and a strain gauge 102 attached to the outer circumferential side 101b of the bearing 101 via a holder 404.
  • each holder 404 In the radial direction, on the outside of the bearing 101, four holders 404 that are approximately L-shaped in side view are arranged at four-fold symmetrical positions around the axis X. Each holder 404 is in contact with the outer peripheral side 101b of the bearing 101 via a radially inner tip portion 445a of a transmission portion 445, which will be described later. In this way, each holder 404 holds the bearing 101. Note that the bearing 101 is arranged above a fixed portion 143, which will be described later, in the axial direction.
  • Each holder 404 holds a strain gauge 102. That is, the sensor device 400 has a first strain gauge 102a held by a first holder 404a, a second strain gauge 102b held by a second holder 404b, and a third holder 404c in a clockwise direction when viewed from above. It has a total of four strain gauges 102, including a third strain gauge 102c held and a fourth strain gauge 102d held by a fourth holder 404d.
  • Two strain gauges 102 adjacent in the circumferential direction are arranged at symmetrical positions with respect to a plane containing the axis X.
  • the angle between the direction from the axis X toward the first strain gauge 102a and the direction from the axis X toward the second strain gauge 102b is 90°. Since all four holders 404 have the same configuration, only one holder 404 will be explained in detail hereafter, and detailed explanations of the other holders 404 will be omitted unless necessary.
  • the holder 404 includes a rectangular plate portion 441 extending in the axial direction, and a rectangular plate portion 441 extending radially outward from the lower end of the plate portion 441 in the axial direction. It has a fixed part 143 having a shape. In the radial direction, a recess 144 that is semicircular in side view and extends in the tangential direction is formed on the inner surface of the plate portion 441 . The recessed portion 144 is formed in the plate portion 441 slightly downward from the axial center.
  • the portion where the concave portion 144 is formed has a thinner wall thickness, and serves as an elastic portion 142 that can undergo elastic strain deformation.
  • Strain gauge 102 is attached to the radially outer surface of elastic portion 142 . Strain deformation of the elastic portion 142 can be detected as a change in the resistance value of the strain gauge 102.
  • An opening 441h which is a circular hole penetrating in the radial direction, is formed in the central portion of the plate portion 441 in the tangential direction and above the recess 144 in the axial direction.
  • a pin-shaped transmission section 445 is inserted into the opening 441h. The transmission portion 445 is fixed to the opening 441h by adhesive or press fitting.
  • the transmission section 445 has a pointed tip 445a.
  • the transmission portion 445 is arranged such that the distal end portion 445a protrudes further inward than the plate portion 441 in the radial direction.
  • the outer peripheral side 101b of the bearing 101 is in point contact with the tip end 445a of the transmission section 445. Therefore, the transmission portion 445 can transmit the displacement of the bearing 101 to the holder 404 via the tip portion 445a.
  • the eccentric member 103 fixed to the shaft S also rotates, and the central axis Y of the bearing 101 also rotates around the axis X accordingly.
  • the central axis Y of the bearing 101 rotates around the axis X in a clockwise direction in a plan view.
  • the elastic portion 142 of the fourth holder 404d transitions to a state in which it is most strained.
  • the sensor device 400 according to this embodiment similarly has the characteristics described above for the sensor device 100 according to the first embodiment.
  • the sensor device 400 according to the present embodiment has a transmission section 445, and the outer peripheral side 101b of the bearing 101 is in contact with the tip 445a of the transmission section 445. Therefore, according to the sensor device 400 according to the present embodiment, it is possible to detect the displacement of the bearing 101 as a point, and the detection accuracy of the rotation angle of the shaft S is improved.
  • the point pressed by the bearing 101 when the holder 404 is strain-deformed is always constant regardless of the rotation angle of the shaft S. Also from this, according to the sensor device 400 according to the present embodiment, the detection accuracy of the rotation angle of the shaft S is improved.
  • FIG. 7 is a perspective view of holder 504, strain gauge 102, and strain sensor 603 of sensor device 500 according to this embodiment.
  • FIG. 8 is a cross-sectional view of sensor device 500 according to this embodiment.
  • the sensor device 500 has a structure in which a torque sensor 600 is integrated and arranged below the sensor device 400 according to the fourth embodiment in the axial direction.
  • members and parts having the same functions and configurations as those in the first and fourth embodiments will be given the same reference numerals as in the first and fourth embodiments, and detailed explanations thereof will be omitted. .
  • the sensor device 500 includes a shaft S, a first bearing 501 having an inner circumferential side 501a and an outer circumferential side 501b, a strain gauge 102 attached to the outer circumferential side 501b of the first bearing 501 via a holder 504, and a torque It has a sensor 600. Since the holder 504 is integrally formed with the holder of the torque sensor 600, the holder of the torque sensor 600 will also be referred to as the holder 504 using the same reference numeral. In addition to the holder 504, the torque sensor 600 includes a second bearing 602 and a strain sensor 603.
  • the first bearing 501 is a ball bearing having an inner ring 501i, an outer ring 501o, and rolling elements.
  • the second bearing 602 is a ball bearing having an inner ring 602i, an outer ring 602o, and rolling elements.
  • the first bearing 501 and the second bearing 602 are not limited to ball bearings, and may be various other bearings such as sleeve bearings.
  • the first bearing 501 is arranged above the second bearing 602 with a space therebetween.
  • the configuration of the first bearing 501 is the same as the configuration of the bearing 101 of the sensor device 100 according to the first embodiment.
  • the holder 504 has a substantially square cylindrical shape in plan view, and includes an inner circumferential member 610 and an outer circumferential member 620.
  • the inner circumferential member 610 is a cylindrical member having a cylindrical inner circumferential surface 610a around the axis X and extending in the axial direction.
  • the outer circumferential member 620 is a member disposed outside the inner circumferential member 610 in the radial direction.
  • the dimensions of the inner peripheral member 610 are the same as the dimensions of the outer peripheral member 620.
  • the axially upper end surface and the axially lower end surface of the inner peripheral member 610 are on the same plane as the axially upper end surface and the axially lower end surface of the outer peripheral member 620, respectively.
  • four connecting portions 630 having a generally rectangular shape in plan view protrude radially outward from the inner circumferential member 610.
  • the four connecting parts 630 are arranged at four-fold symmetrical positions around the axis X.
  • a strain body 621 having a rectangular shape in plan view and a substantially L-shape in side view is connected to each connection portion 630.
  • the strain body 621 is a deformable portion that deforms by receiving stress, and deforms elastically or plastically by receiving stress.
  • the four strain bodies 621 constitute the outer peripheral member 620 in this embodiment. Therefore, the connecting portion 630 connects the inner peripheral member 610 and the outer peripheral member 620. Since all four strain bodies 621 have the same configuration, only one strain body 621 will be described in detail hereafter, and detailed explanations of the other strain bodies 621 will be omitted.
  • the strain body 621 (outer peripheral member 620) faces the inner peripheral member 610 with a gap 640 extending in the tangential direction.
  • the gap 640 connects to the through hole 641, which is circular or approximately circular in side view, on the axially lower side of the through hole 641 and slightly inward in the radial direction, and has a width (radial width) smaller than the diameter of the through hole 641. narrow slit 642.
  • a concave portion recessed radially outward is formed in the radially inner surface of the strain body 621 (outer peripheral member 620), and the connecting portion 630 has a recessed portion recessed toward the radially outer side.
  • a recess that is recessed upward in the axial direction is formed in the lower surface, and a recess that is recessed inward in the radial direction is formed in the inner peripheral member 610 on the outer surface in the radial direction.
  • the strain body 621 (outer peripheral member 620) has a second elastic portion 622. That is, a portion of the strain body 621 (outer peripheral member 620) functions as the elastic portion 622. Of the portion of the strain body 621 extending along a plane perpendicular to the radial direction, a region slightly above the center in the axial direction (the region in which the recess is formed) is the second elastic portion 622. It becomes. In the radial direction, the second elastic portion 622 and the inner peripheral member 610 face each other with a gap 640 in between. The second elastic portion 622 has a radially recessed portion on a surface facing the inner peripheral member 610.
  • the second elastic portion 622 Due to the formation of the concave portion, the second elastic portion 622 has a thinner wall thickness (thickness in the radial direction) than other portions of the strain body 621 (outer peripheral member 620), and has elasticity. Strain deformation is more likely to occur.
  • the torque sensor 600 includes a plurality (four in this embodiment) of second elastic portions 622 as a whole.
  • the plurality of second elastic portions 622 are arranged in four-fold symmetrical positions in line on the outside of the holder 504 (radially outside the inner peripheral member 610) in the circumferential direction (FIG. 7).
  • a strain sensor 603 is attached to the radially outer surface of the second elastic portion 622.
  • the second elastic portion 622 and the strain sensor 603 each extend along a plane parallel to the axial direction.
  • the strain sensor 603 is installed so as to be able to detect strain in the second elastic portion 622 in a direction along a plane perpendicular to the tangential direction. Therefore, when the strain sensor 603 is a strain gauge, it is attached to the second elastic portion 622 such that the grid orientation (typically, the longitudinal direction of the strain gauge) is in the axial direction.
  • the strain sensor 603 is a strain gauge, the strain in the second elastic portion 622 is detected as a change in resistance value.
  • a fixing portion 623 connected to the external device 10 is arranged outside the second elastic portion 622 of the strain body 621 in the radial direction.
  • the fixing portion 623 is a rectangular plate-shaped portion extending radially outward from the axially lower end of the second elastic portion 622 .
  • a circular through hole 623h is formed near the center of the fixing portion 623.
  • the strain body 621 is fixed to the external device 10 via a spacer 605 by a bolt 604 inserted into the through hole 623h. Thereby, the entire holder 504 is fixed to the external device 10.
  • the second bearing 602 is arranged inside the inner peripheral member 610 of the holder 504.
  • the second bearing 602 is held by an inner peripheral member 610 of the holder 504.
  • the inner ring 602i of the second bearing 602 is bonded or press-fitted to the outer circumferential surface (radially outer surface) of the cylindrical shaft S. Thereby, the inner ring 602i of the second bearing 602 is fixed to the shaft S.
  • the outer ring 602o of the second bearing 602 is press-fitted into the inner peripheral surface 610a of the inner peripheral member 610 of the holder 504.
  • the second bearing 602 rotatably supports the shaft S with respect to the holder 504.
  • the lower end of the shaft S in the axial direction projects from the through hole 11 of the external device 10 to the outside of the external device 10 .
  • the holder 504 has an annular contact portion 611 that protrudes radially inward at the lower end in the axial direction.
  • the contact portion 611 protrudes radially inward from the inner peripheral member 610 of the holder 504.
  • the contact portion 611 is in contact with the axially lower end surface of the outer ring 602o of the second bearing 602. Thereby, the contact portion 611 supports the second bearing 602 in a state in which downward movement in the axial direction is restricted.
  • a recess 612 that is semicircular or approximately semicircular in side view is formed near the axially lower end of the inner circumferential surface 610a of the inner circumferential member 610.
  • the recess 612 is formed in an annular shape around the axis X above the contact portion 611 in the axial direction.
  • the axially lower end of the concave surface of the recessed portion 612 is smoothly connected to the axially upper end surface of the contact portion 611 .
  • the shaft S is a crankshaft provided with pedals.
  • a force is applied that tends to tilt the shaft S downward in the vertical direction, so the second bearing 602 tends to move in the radial direction, causing a part of the holder 504 to move outward in the radial direction. being pushed towards.
  • stress tends to concentrate on the second elastic portion 622 of the strain body 621, so that the second elastic portion 622 undergoes elastic strain deformation.
  • the four strain bodies 621 are located at four-fold symmetrical positions around the axis X, so that stress in all directions can be detected more accurately. Depending on the detected stress, the output of the motor of the electrically assisted bicycle can be adjusted.
  • the torque sensor 600 does not use a magnetostrictive sensor, but has a simple configuration including a holder 504, a second bearing 602, and a strain sensor 603, and has the detection required when using a magnetostrictive sensor. Since there is no need to arrange a coil or the like around the shaft S, it is possible to downsize the device. Further, since processing such as attaching a magnetic layer to the shaft S is not necessary, manufacturing is easy.
  • the strain body 621 (outer peripheral member 620) faces the inner peripheral member 610 with a gap 640 in between. Thereby, in the torque sensor 600, the second elastic portion 622 of the strain body 621 is easily strained and deformed, and stress can be detected with high sensitivity.
  • the wall thickness near the axially lower end of the inner circumferential member 610 is thinner due to the formation of the recessed portion 612, so that the contact portion 611 moves toward the axially lower side. Almost deformed elastically. As a result, even when a preload is applied to the second bearing 602 downward in the axial direction, the contact portion 611 is elastically deformed, so that the influence of the preload can be absorbed. Therefore, in the torque sensor 600, the preload on the second bearing 602 is suppressed from appearing as strain in the second elastic portion 622, and the strain sensor 603 can detect stress with high sensitivity.
  • a portion of the sensor device 500 above the torque sensor 600 in the axial direction has substantially the same configuration as the sensor device 400 according to the fourth embodiment. However, in the sensor device 500, there is no fixed portion 143 of the holder 404 of the sensor device 400 according to the fourth embodiment, and the four plate portions 541 are arranged in the axial direction of the inner peripheral member 610 of the holder 504. It is erected directly on the upper end face toward the upper side in the axial direction.
  • the four plate parts 541 are arranged at four-fold symmetrical positions around the axis X on the outside of the first bearing 501 in the radial direction. In the circumferential direction, the four plate portions 541 are arranged at positions corresponding to the four strain bodies 621. Each plate portion 541 is in contact with the outer peripheral side 501b of the first bearing 501 via the radially inner tip portion 545a of the transmission portion 545. In this way, the holder 504 holds the first bearing 501. Note that the first bearing 501 is arranged above the axially upper end surface of the inner circumferential member 610 in the axial direction.
  • Each plate portion 541 holds a strain gauge 102. That is, the holder 504 of the sensor device 500 includes, clockwise in plan view, the first strain gauge 102a held by the first plate part 541a, the second strain gauge 102b held by the second plate part 541b, A total of four strain gauges 102 are held, including a third strain gauge 102c held by a third plate part 541c and a fourth strain gauge 102d held by a fourth plate part 541d.
  • Two strain gauges 102 adjacent in the circumferential direction are arranged at symmetrical positions with respect to a plane containing the axis X.
  • the angle between the direction from the axis X toward the first strain gauge 102a and the direction from the axis X toward the second strain gauge 102b is 90°. Since all four plate parts 541 have the same configuration, only one plate part 541 will be explained in detail hereafter, and detailed explanation of the other plate parts 541 will be omitted unless necessary.
  • a recess 544 that is semicircular in side view and extends in the tangential direction is formed on the inner surface of the plate portion 541.
  • the recessed portion 544 is formed near the lower end of the plate portion 541 in the axial direction.
  • the portion where the recessed portion 544 is formed has a thinner wall thickness, and serves as a first elastic portion 542 capable of elastic strain deformation.
  • Strain gauge 102 is attached to the radially outer surface of first elastic portion 542 . Strain deformation of the first elastic portion 542 can be detected as a change in the resistance value of the strain gauge 102.
  • An opening 541h which is a circular hole penetrating in the radial direction, is formed in the central portion of the plate portion 541 in the tangential direction and above the recess 544 in the axial direction.
  • a pin-shaped transmission portion 545 is inserted into the opening 541h.
  • the transmission portion 545 is fixed to the opening 541h by adhesive or press fitting.
  • the transmission section 545 has a pointed tip 545a.
  • the transmission portion 545 is arranged such that the tip portion 545a protrudes inward from the plate portion 541 in the radial direction.
  • the outer peripheral side 501b of the first bearing 501 is in point contact with the tip 545a of the transmission section 545. Therefore, the transmission portion 545 can transmit the displacement of the first bearing 501 to the plate portion 541 via the tip portion 545a.
  • the maximum thickness portion 103a of the eccentric member 103 is located close to the third plate portion 541c, and the minimum thickness portion 103b of the eccentric member 103 is located close to the first plate portion 541a. Therefore, the third plate portion 541c is pressed radially outward by the first bearing 501. Note that the second plate portion 541b and the fourth plate portion 541d adjacent to the third plate portion 541c are also slightly pressed radially outward by the first bearing 501.
  • the first elastic portion 542 of the third plate portion 541c has undergone the largest strain deformation, and the upper side of the third plate portion 541c in the axial direction is warped toward the outside in the radial direction.
  • the situation is as follows.
  • the first elastic portions 542 of the second plate portion 541b and the fourth plate portion 541d adjacent to the third plate portion 541c are in a slightly strained state.
  • the first elastic portion 542 of the first plate portion 541a is in a state where it is least strained or not strained at all.
  • the eccentric member 103 fixed to the shaft S also rotates, and the central axis Y of the first bearing 501 also rotates around the axis X accordingly.
  • the central axis Y of the first bearing 501 rotates around the axis X in a clockwise direction in a plan view.
  • the central axis Y of the first bearing 501 rotates 90° clockwise in plan view from the state shown in FIG. 8, the first elastic portion 542 of the fourth plate portion 541d undergoes the most strain deformation. Transition to state.
  • the sensor device 500 according to the present embodiment similarly has the characteristics described above for the sensor device 400 according to the fourth embodiment. Further, in the sensor device 500 according to this embodiment, the torque sensor 600 and the holder 504 are integrally formed. Therefore, when both a sensor for detecting a rotation angle (cadence sensor, etc.) and a torque sensor are mounted, such as when applied to a power-assisted bicycle, the overall size can be reduced.
  • the strain gauge 102 attached to the plate portion 541 and the strain sensor 603 attached to the torque sensor 600 are arranged at corresponding positions in the circumferential direction. Further, when the strain sensor 603 is a strain gauge, all the strain gauges 102 and the strain sensor 603 are oriented in the same direction (typically, the longitudinal direction is oriented in the same direction as the axial direction). As described above, the workability when attaching the strain gauge 102 and the strain sensor 603 is improved.
  • the stress generated in the holder 504 due to the force that causes the shaft S to tilt is absorbed by the outer peripheral member 620 of the torque sensor 600 disposed on the lower side in the axial direction. Therefore, it is possible to suppress the stress from affecting the strain gauge 102 disposed on the upper side in the axial direction. Therefore, in the sensor device 500 according to the present embodiment, the rotation angle of the shaft S can be detected with higher accuracy.
  • the sensor device of the present invention has been described above with reference to preferred embodiments, the sensor device of the present invention is not limited to the configuration of the above embodiments.
  • each sensor device according to the above embodiments is described with the assumption that it will be used as a cadence sensor for an electrically assisted bicycle, but the sensor device of the present invention is one that is used as a cadence sensor for an electrically assisted bicycle. Not limited to.
  • an eccentric member is arranged between the bearing and the shaft, but the sensor device of the present invention is not limited to this, and the sensor device of the present invention can connect the bearing and the shaft without using an eccentric member.
  • They may be eccentric to each other.
  • shafts or bearings that themselves have an eccentric shape may be used.
  • the bearing and the shaft may be made eccentric to each other by filling a resin or the like between the shaft and the bearing and hardening the resin.
  • the shape of the eccentric member is not particularly limited. For example, a protrusion may be provided on the outer peripheral surface of the shaft, and this may be used as an eccentric member.
  • the number of strain gauges may be one, two, or three.
  • the number may be five or more. Even when the number of strain gauges is one, it is possible to detect the speed of rotation. However, in order to detect the rotation angle, it is preferable that the number of strain gauges is two or more.
  • the first strain gauge and the second strain gauge are arranged at symmetrical positions with respect to a plane including the central axis of the shaft, and
  • the angle between the direction toward the second strain gauge and the direction from the central axis of the shaft toward the second strain gauge is 90°.
  • the angle may be any angle.
  • it is preferable that the angle is not 180°.
  • the portion above the torque sensor 600 in the axial direction has substantially the same configuration as the sensor device 400 according to the fourth embodiment, but the torque A portion above the sensor 600 in the axial direction may have substantially the same configuration as the sensor device according to the other embodiments described above.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
  • Mounting Of Bearings Or Others (AREA)
  • Rolling Contact Bearings (AREA)

Abstract

La présente invention concerne un dispositif de capteur ayant une excellente résistance environnementale.　Un dispositif de détection (100, 200, 300, 400, 500) comprend un arbre (S), un palier (101, 501) présentant une circonférence interne (101a, 501a) et une circonférence externe (101b, 501b), et une jauge de contrainte (102) fixée à la circonférence externe (101b, 501b) du palier (101, 501), directement ou par l'intermédiaire d'un autre élément. L'arbre (S) est disposé dans le sens radial à l'intérieur du côté de la circonférence interne (101a, 501a) du palier (101, 501). Le palier (101, 501) et l'arbre (S) sont excentriques l'un par rapport à l'autre.
PCT/JP2023/017223 2022-05-13 2023-05-08 Dispositif de capteur WO2023219050A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022079475A JP2023167923A (ja) 2022-05-13 2022-05-13 センサ装置
JP2022-079475 2022-05-13

Publications (1)

Publication Number Publication Date
WO2023219050A1 true WO2023219050A1 (fr) 2023-11-16

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PCT/JP2023/017223 WO2023219050A1 (fr) 2022-05-13 2023-05-08 Dispositif de capteur

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JP (1) JP2023167923A (fr)
TW (1) TW202344804A (fr)
WO (1) WO2023219050A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56163410A (en) * 1980-05-22 1981-12-16 Mitsubishi Electric Corp Abrasion detector of plain bearing
JP2001515415A (ja) * 1995-10-09 2001-09-18 オハイオ エレクトロニック イングレイバーズ インク 彫刻方法と装置
US20210095999A1 (en) * 2019-10-01 2021-04-01 Infineon Technologies Ag Sensing of a rotational angle

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56163410A (en) * 1980-05-22 1981-12-16 Mitsubishi Electric Corp Abrasion detector of plain bearing
JP2001515415A (ja) * 1995-10-09 2001-09-18 オハイオ エレクトロニック イングレイバーズ インク 彫刻方法と装置
US20210095999A1 (en) * 2019-10-01 2021-04-01 Infineon Technologies Ag Sensing of a rotational angle

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JP2023167923A (ja) 2023-11-24

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