JP2013064721A - Rear hub for bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rear hub for a bicycle which can measure driving force and is hardly affected by assembly accuracy.SOLUTION: A rear hub 10 includes a hub spindle 20, a drive part 2, a hub shell 24, a first counter part 54, a second counter part 56, and a driving force measurement part 26. The drive part 22 is freely rotatably supported by the hub spindle 20 and can install a sprocket aggregate 80. The hub shell 24 is freely rotatably supported by the hub spindle 20 and rotation of the drive part 22 is communicated thereto. The first counter part 54 is provided for the drive part 22. The second counter part 56 is provided for the hub shell 24. The driving force measurement part 26 has a sensor 58. The sensor 58 can measure a gap or displacement of the gap between the first counter part and the second counter part 56.

Description

  The present invention relates to a hub, and more particularly to a bicycle rear hub constituting a hub of a bicycle rear wheel.

  The bicycle rear hub includes a hub shaft that is disposed at the center of rotation of the rear wheel, a hub shell that is rotatably mounted around the hub shaft, and a free wheel that is disposed adjacent to the hub shell in the axial direction. . The free wheel transmits the rotation of the sprocket meshing with the chain to the hub shell. 2. Description of the Related Art A bicycle rear hub in which a driving force measuring unit capable of measuring a rider's driving force is disposed between the free wheel and the hub shell is conventionally known (see, for example, Patent Document 1).

  A conventional bicycle rear hub has a connecting member that connects a freewheel and a hub shell. The connecting member is formed in a cylindrical shape, a sprocket is attached to one end, and the other end is connected to the hub shell. The connecting member is provided with a strain gauge for detecting the twist of the connecting portion, and the amount of twist of the connecting portion is detected. The driving force of the rider is measured based on the measured twist amount.

U.S. Pat. No. 6,187,797

  In the conventional rear hub, the strain gauge is directly attached to the connecting portion, and for example, it is necessary to make the thickness of the adhesive to be attached uniform, so that it is difficult to assemble with high accuracy.

  An object of the present invention is to provide a bicycle rear hub that can measure a driving force and is less susceptible to the accuracy of assembly.

  A bicycle rear hub according to a first aspect includes a hub shaft, a drive unit, a hub shell, at least one first opposed unit, at least one second opposed unit, and a drive force measuring unit. The drive unit is rotatably supported by the hub shaft and can be mounted with a drive force transmission member. The hub shell is rotatably supported by the hub shaft, and the rotation of the drive unit is transmitted. At least one first facing portion is provided in the driving portion. At least one second facing portion is provided in the hub shell and can be opposed to the first facing portion with a gap. The driving force measurement unit includes at least one sensor capable of measuring the interval between the first opposed unit and the second opposed unit or the displacement of the interval.

  In this bicycle rear hub, when the rotation of the drive unit is transmitted to the hub shell, the distance between the first opposed unit provided in the drive unit and the second opposed unit provided in the hub shell is the transmitted driving force (torque). Will change accordingly. A change in the interval between the first opposing portion and the second opposing portion or the change in the interval between the first opposing portion and the second opposing portion can be detected by the sensor. Here, since the relative distance between the first facing part and the second facing part or the displacement of the distance is detected by the sensor, the influence on the measurement result due to how the sensor is attached can be suppressed. Can be less affected.

  The bicycle rear hub according to a second aspect is the bicycle rear hub according to the first aspect, wherein the first facing portion and the second facing portion are opposed to each other in the rotational direction of the drive portion and the hub shell. Accordingly, when the driving force is transmitted from the driving unit to the hub shell, the driving unit is twisted with respect to the hub shell, and the first facing portion approaches the second facing portion according to the driving force. Therefore, the driving force can be detected with high accuracy.

  A bicycle rear hub according to a third aspect is the bicycle rear hub according to the first or second aspect, wherein the first facing portion protrudes from the outer peripheral portion of the drive portion. In this case, since the first facing portion approaches the hub shell, the first facing portion can be easily made to face the second facing portion provided in the hub shell.

  A bicycle rear hub according to a fourth aspect of the present invention is the bicycle rear hub according to any one of the first to third aspects, wherein the second facing portion protrudes from the inner peripheral portion of the hub shell. In this case, since the second facing portion approaches the driving portion, the first facing portion can be easily made to face the second facing portion.

  The bicycle rear hub according to a fifth aspect of the present invention is the bicycle rear hub according to any one of the first to fourth aspects, wherein the drive unit has a coupling portion coupled to the hub shell.

  A bicycle rear hub according to a sixth aspect is the bicycle rear hub according to the fifth aspect, wherein the connecting portion is provided integrally with the first facing portion. In this case, since the connecting portion is provided integrally with the first facing portion, the configuration of the driving portion is simple.

  A bicycle rear hub according to a seventh aspect is the bicycle rear hub according to the fifth aspect, wherein the connecting portion is provided separately from the first facing portion. In this case, the freedom degree of the shape of a connection part becomes high and it is easy to set the rigidity of a connection part arbitrarily. For example, it is possible to increase the displacement of the distance between the first facing portion and the second facing portion by making the rigidity of the connecting portion lower than other portions of the driving portion. Thereby, the output of the sensor with respect to the driving force can be improved.

  A bicycle rear hub according to an eighth aspect is the bicycle rear hub according to the seventh aspect, wherein the connecting portion is formed in an annular shape, and a plurality of through holes extending in the hub axial direction are formed. In this case, the rigidity of the connecting portion can be arbitrarily set depending on the shape of the through-hole.

  A bicycle rear hub according to a ninth aspect is the bicycle rear hub according to any of the fifth to eighth aspects, wherein the connecting portion and the hub shell are coupled by serration or adhesion. In this case, the connecting structure between the hub shell and the connecting portion is simplified.

  A bicycle rear hub according to a tenth aspect of the invention is the bicycle rear hub according to any of the fifth to ninth aspects, wherein the connecting portion and the hub shell are connected at a central portion of the hub shell in the hub axial direction. In this case, since the axial direction length of the hub shaft of the connecting portion is increased, the connecting portion is easily twisted and the left and right twists in the hub shell can be suppressed.

  A bicycle rear hub according to an eleventh aspect of the invention is the bicycle rear hub according to any one of the first to tenth aspects, wherein a plurality of sets of first opposing portions and second opposing portions are provided. Thereby, since the space | interval of a 1st opposing part and a 2nd opposing part or the displacement of an interval can be detected in multiple places, detection accuracy improves.

  The bicycle rear hub according to a twelfth aspect of the present invention is the bicycle rear hub according to the first or second aspect, wherein the sensor is provided in at least one of the plurality of first and second opposed portions. In this case, a sensor can be provided in either or both of the first facing portion and the second facing portion depending on the type of sensor.

  The bicycle rear hub according to a thirteenth aspect is the bicycle rear hub according to the twelfth aspect, wherein the plurality of sensors are provided at the first facing portion.

  The bicycle rear hub according to a fourteenth aspect of the present invention is the bicycle rear hub according to the twelfth aspect, wherein the plurality of sensors are provided at the second facing portion.

  The bicycle rear hub according to a fifteenth aspect is the bicycle rear hub according to the twelfth aspect, wherein at least one of the plurality of sets of the first facing portion and the second facing portion is provided with a sensor in the first facing portion. In at least one of the groups, a sensor is provided in the second facing portion.

  The bicycle rear hub according to a sixteenth aspect of the present invention is the bicycle rear hub according to any one of the eleventh to fifteenth aspects, wherein the plurality of sensors are eddy current sensors. In this case, the interval or the displacement of the interval can be measured using a high frequency magnetic field.

  The bicycle rear hub according to a seventeenth aspect of the present invention is the bicycle rear hub according to any of the eleventh to fifteenth aspects, wherein the plurality of sensors are capacitive sensors. In this case, it is possible to detect the interval or the displacement of the interval by providing a capacitor in the first opposing portion and the second opposing portion and changing the capacitance.

  The bicycle rear hub according to an eighteenth aspect of the invention is the bicycle rear hub according to the seventeenth aspect, wherein the capacitance type sensor includes a capacitor.

  The bicycle rear hub according to a nineteenth aspect of the present invention is the bicycle rear hub according to any of the eleventh to fifteenth aspects, wherein the plurality of sensors are optical sensors. In this case, the interval or the displacement of the interval can be detected by the phase difference between the irradiation light such as laser light and the reflected light.

  The bicycle rear hub according to a twentieth aspect of the present invention is the bicycle rear hub according to any of the eleventh to fifteenth aspects, wherein the sensor is a sensor having a coil. In this case, an interval or a displacement of the interval can be detected by changing the impedance of the coil due to the electromagnetic induction action.

  The bicycle rear hub according to a twenty-first aspect is the bicycle rear hub according to any of the eleventh to twentieth aspects, wherein the plurality of sensors are connected in series. In this case, since it is not necessary to separately provide signal processing circuits for detecting signals from a plurality of sensors, the configuration can be simplified and current consumption can be reduced. Further, since errors in the outputs of a plurality of sensors arranged at different positions are canceled out, it is possible to accurately detect the interval or the displacement of the interval.

  The bicycle rear hub according to a twenty-second aspect is the bicycle rear hub according to any one of the eleventh to twentieth aspects, wherein the plurality of sensors are connected in parallel. In this case, since it is not necessary to separately provide signal processing circuits for detecting signals from a plurality of sensors, the configuration can be simplified and current consumption can be reduced. In addition, since the outputs of a plurality of sensors arranged at different positions are canceled out, it is possible to accurately detect the interval or the displacement of the interval.

  The bicycle rear hub according to a twenty-third aspect of the invention is the bicycle rear hub according to any of the eleventh to twenty-second aspects, further comprising a wireless transmission unit that wirelessly transmits information based on the output of the sensor to the outside. For example, even if the sensor rotates with the hub shell, the output can be easily taken out.

  A bicycle rear hub according to a twenty-fourth aspect of the invention is the bicycle rear hub according to any one of the first to twenty-third aspects, further comprising a power source for supplying electric power to the sensor. In this case, since a power source is provided, it is not necessary to provide a power source separately from the rear hub.

  The bicycle rear hub according to a twenty-fifth aspect of the present invention is the bicycle rear hub according to the twenty-fourth aspect, wherein the power source is a battery. In this case, the configuration of the power supply is simplified.

  The bicycle rear hub according to a twenty-sixth aspect is the bicycle rear hub according to the twenty-fourth aspect, wherein the power source is a generator. In this case, power generation occurs when the bicycle is running, so charging or battery replacement is not necessary.

  A bicycle rear hub according to a twenty-seventh aspect includes a hub shaft, a drive unit, a hub shell, and a drive force measurement unit. The drive unit is rotatably supported on the hub shaft, and a drive force transmission member can be attached thereto. The hub shell is rotatably supported by the hub shaft, and the rotation of the drive unit is transmitted. The driving force measuring unit can measure the driving force transmitted from the driving unit to the hub shell. The drive unit includes an outer cylindrical part to which the driving force transmission member is attached, an inner cylindrical part disposed inside the outer cylindrical part, and a measured part formed integrally with the inner cylindrical part.

  In the bicycle rear hub, when the rotation of the drive unit is transmitted to the hub shell, the measurement target provided in the drive unit is twisted according to the transmitted driving force (torque). This deformation can be measured by the driving force measuring unit. By configuring the inner cylindrical part and the measured part integrally, the noise measured by the driving force measuring part is reduced compared to the case where the inner cylindrical part and the measured part are configured separately. Or torsional bias of the part to be measured is less likely to occur, so that the measurement accuracy can be improved and the gravity can be reduced.

  The bicycle rear hub according to a twenty-eighth aspect of the present invention is the bicycle rear hub according to the twenty-seventh aspect, wherein the inner cylindrical portion and the outer cylindrical portion constitute a one-way clutch. In this case, only rotation in one direction of the outer cylindrical portion (for example, rotation in the traveling direction of the bicycle) is transmitted to the inner cylindrical portion.

  A bicycle rear hub according to a twenty-ninth aspect of the invention is the bicycle rear hub according to the twenty-seventh or twenty-eighth aspect, wherein the drive portion further includes a connecting portion connected to the hub shell. The connecting portion is connected to the inside of the hub shell. In this case, regardless of the outer shape of the rear hub, the drive unit and the hub shell can be connected, and the degree of freedom in designing the outer shape of the rear hub is maintained.

  A bicycle rear hub according to a thirtieth aspect is the bicycle rear hub according to the twenty-ninth aspect, wherein the connecting portion is connected to an intermediate portion in the axial direction of the hub shell. In this case, since the connecting portion is connected to the intermediate portion in the axial direction of the hub shell, an increase in the weight of the rear hub can be suppressed.

  A bicycle rear hub according to a thirty-first aspect is the bicycle rear hub according to the twenty-ninth or thirty-third aspect, wherein a portion to be measured is provided between the connecting portion and the inner cylindrical portion. In this case, since the measured portion is provided between the connecting portion with the hub shell and the inner cylindrical portion, the measured portion is easily deformed.

  The bicycle rear hub according to a thirty-second aspect is the bicycle rear hub according to any of the thirty-ninth to thirty-first aspects, wherein the driving force measuring portion is disposed inside the hub shell.

  A bicycle rear hub according to a thirty-third aspect is the bicycle rear hub according to any of the thirty-ninth to thirty-second aspects, wherein the connecting portion is screwed and fixed to the hub shell. In this case, the structure which connects a connection part to a hub shell becomes simple.

  The bicycle rear hub according to a thirty-fourth aspect of the invention is the bicycle rear hub according to any one of the twenty-ninth to thirty-third aspects, wherein the driving force measuring unit has at least one strain gauge. In this case, since the deformation of the portion to be measured is measured by the strain gauge, the driving force can be accurately detected even with a slight twist.

  The rear hub for a rolling vehicle according to a thirty-fifth aspect of the invention is the bicycle rear hub according to any of the twenty-ninth to thirty-third aspects, wherein the driving force measuring unit is opposed to the magnetostrictive element disposed on the outer peripheral surface of the measured part and the magnetostrictive element. And a detection coil disposed on the inner peripheral surface of the hub shell. In this case, since the driving force can be detected by the magnetostrictive element, the driving force can be measured with higher accuracy even with a slight twist.

  According to the present invention, since the driving force is detected by the interval between the first opposing portion and the second opposing portion or the change in the interval, the influence on the measurement result due to the sensor mounting method can be suppressed, and the assembly accuracy can be reduced. Can be less affected by

1 is a half-sectional view of a bicycle rear hub according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of a main part of the bicycle rear hub in FIG. 1. Sectional drawing seen from the cut surface line III-III of FIG. Sectional drawing seen from the cut surface line IV-IV of FIG. The figure equivalent to FIG. 2 of 2nd Embodiment. Sectional drawing seen from the cutting surface line VI-VI of FIG. The figure equivalent to FIG. 4 of 3rd Embodiment. The figure which shows an example of the connection form of the some sensor of 3rd Embodiment, and a signal processing circuit. The figure corresponded in FIG. 8 of the modification of 3rd Embodiment. The figure equivalent to FIG. 2 of 4th Embodiment. The figure equivalent to FIG. 4 of 4th Embodiment. The top view which shows the sensor using the coil of 4th Embodiment. The block diagram which shows the connection state of the coil of 4th Embodiment. The figure equivalent to FIG. 13 of the modification of 4th Embodiment. The figure equivalent to FIG. 4 of the modification of 4th Embodiment. FIG. 10 is a half-sectional view of a bicycle rear hub according to a fifth embodiment. FIG. 17 is a cross-sectional view of a main part of the bicycle rear hub in FIG. 16. The figure corresponded in FIG. 17 of the modification of 5th Embodiment. The figure equivalent to FIG. 17 of 6th Embodiment.

<First Embodiment>
As shown in FIG. 1, the bicycle rear hub 10 according to the first embodiment of the present invention can be mounted on a hub axle mounting portion 102 provided at the rear portion of the bicycle frame. The rear hub 10 includes a hub shaft 20, a drive unit 22, a hub shell 24, a drive force measurement unit 26, and a wireless transmission unit 28. The hub shell 24 is rotatably supported on the hub shaft 20 by a first bearing 46. The drive unit 22 is rotatably supported by the hub shaft 20 by the second bearing 47. The driving force measuring unit 26 can measure the driving force of the rider. The wireless transmission unit 28 wirelessly transmits information regarding the measured driving force. The information on the driving force transmitted wirelessly is displayed on a cycle computer (not shown) that can be mounted on a bicycle handle, for example. The cycle computer also displays information such as bicycle speed, crank rotation speed (cadence), and travel distance.

<Hub shaft>
The hub shaft 20 includes a hollow shaft main body 30 to which the quick release mechanism 29 is mounted, a first lock nut 32 to be mounted on a first end portion (left end portion in FIG. 2) of the shaft main body 30, and a shaft main body. 30 and a second lock nut 34 attached to the second end portion (the end portion on the right side of FIG. 2). The hub shaft mounting portion 102 can be mounted on the first lock nut 32 and the second lock nut 34. Here, the configuration in which the first lock nut 32 and the second lock nut 34 are mounted on the hub shaft mounting portion 102 is described, but the shaft main body 30 may be mounted on the hub shaft mounting portion 102 of the frame. Good.

  As shown in FIG. 2, an internal thread portion 30 a is formed on the inner peripheral surface of the first end portion of the shaft body 30. A first male screw portion 30b and a second male screw portion 30c are formed on the outer peripheral surfaces of the first and second end portions of the shaft body 30, respectively. The first lock nut 32 has a male screw portion that is screwed into the female screw portion 30 a, and is screwed and fixed to the shaft main body 30. The second lock nut 34 has a female screw portion that is screwed into the second male screw portion 30 c, and is screwed and fixed to the shaft main body 30.

<Driver>
The drive unit 22 includes a member called a so-called free wheel. The drive unit 22 includes a first member 40 that is rotatably supported by the hub shaft 20, a second member 42 that is disposed on the outer peripheral side of the first member 40, and a space between the first member 40 and the second member 42. The one-way clutch 44 and the connecting portion 52 are provided.

  The first member 40 is a cylindrical member that is rotatably supported by the hub shaft 20 by the second bearing 47. The second bearing 47 includes a second inner ring body 47a, a second outer ring body 47b, and a plurality of second rolling elements 47c. The second inner ring body 47 a has a screw formed on the outer peripheral portion thereof, and is fixed by being screwed into the second male screw portion 30 c of the shaft body 30. The second outer ring body 47 b has a screw formed on the inner peripheral portion thereof, and is screwed and fixed to a male screw portion formed on the outer peripheral surface of the first member 40. The plurality of second rolling elements 47c are provided between the second inner ring body 47a and the second outer ring body 47b at intervals in the circumferential direction. The 2nd rolling element 47c is rotatably hold | maintained at the retainer which is not shown in figure, and is arrange | positioned at predetermined intervals in the circumferential direction. The second rolling element 47c may be a sphere or a roller.

  The first member 40 has a first tube portion 40b having a recess 40a in which the clutch pawl 44a of the one-way clutch 44 is accommodated. The first end portion (the left end portion in FIG. 2) of the first member 40 extends to the inner peripheral side of the hub shell 24. The first member 40 has a second cylinder part 40c having a diameter larger than that of the first cylinder part 40b and a diameter larger than that of the second cylinder part 40c on the first end part side (left side in FIG. 2) of the first cylinder part 40b. The third tube portion 40d is provided in this order. The second outer ring body 47b of the second bearing 47 is fixed to the second end portion (right end portion in FIG. 2) of the first cylindrical portion 40b. A third inner ring surface 48a constituting the third bearing 48 is formed on the outer peripheral surface of the boundary portion between the first tube portion 40b and the second tube portion 40c. A first serration portion 40e to which the connecting portion 52 is connected is formed on the outer peripheral surface of the second cylindrical portion 40c. A fifth inner ring surface 50a of a fifth bearing 50 for rotatably supporting the hub shell 24 on the drive unit 22 is formed on the outer peripheral surface of the third cylindrical portion 40d.

  The second member 42 is a cylindrical member that is rotatably supported by the third bearing 48 and the fourth bearing 49 with respect to the first member 40. The third bearing 48 is formed by the above-described third inner ring surface 48a, third outer ring surface 48b, and a plurality of third rolling elements 48c. The third outer ring surface 48 b is formed on the inner peripheral surface of the first end portion (the left end portion in FIG. 2) of the second member 42. The plurality of third rolling elements 48c are provided between the third inner ring surface 48a and the third outer ring surface 48b at intervals in the circumferential direction. The 3rd rolling element 48c is rotatably hold | maintained at the retainer which is not shown in figure, and is arrange | positioned at predetermined intervals in the circumferential direction. The third rolling element 48c may be a sphere or a roller.

  The fourth bearing 49 is formed by a fourth inner ring surface 49a formed on the outer peripheral surface of the second outer ring body 47b, a fourth outer ring surface 49b, and a plurality of fourth rolling elements 49c. The fourth outer ring surface 49b is formed on the inner peripheral surface of the intermediate portion of the second member 42 in the hub axial direction. The plurality of fourth rolling elements 49c are provided between the fourth inner ring surface 49a and the fourth outer ring surface 49b at intervals in the circumferential direction. The 4th rolling element 49c is rotatably hold | maintained at the retainer which is not shown in figure, and is arrange | positioned at predetermined intervals in the circumferential direction. The fourth rolling element 49c may be a sphere or a roller.

  As shown in FIG. 1, the second member 42 has a sprocket mounting portion 42 a for mounting the sprocket assembly 80 on the outer peripheral surface. The sprocket assembly 80 rotates integrally with the second member 42. The sprocket assembly 80 is an example of a driving force transmission member. The sprocket mounting part 42a has, for example, a spline having a convex part or a concave part arranged on the outer peripheral part at intervals in the circumferential direction. As shown in FIG. 1, the sprocket assembly 80 has a plurality of (for example, nine) sprockets 80 a to 80 i having different numbers of teeth. The rotation of the crank (not shown) is transmitted to the drive unit 22 by the chain 81 that meshes with any one of the sprocket assemblies 80. Here, although a plurality of sprockets are mounted on the sprocket mounting portion 42a, the number of sprockets mounted on the sprocket mounting portion 42a may be one.

  The one-way clutch 44 is provided to transmit only the rotation of the second member 42 in the traveling direction of the bicycle to the first member 40. Thereby, only the rotation of the crank in the traveling direction is transmitted to the hub shell 24. Further, the rotation of the hub shell 24 in the traveling direction is not transmitted to the second member 42. The one-way clutch 44 biases the clutch pawl 44a provided in the recess 40a so as to be swingable in the first posture and the second posture, the ratchet teeth 44b formed on the inner peripheral surface of the second member 42, and the clutch pawl 44a. Biasing member 44c. The clutch pawl 44a comes into contact with the ratchet teeth 44b in the first posture and disengages from the ratchet teeth 44b in the second posture. The urging member 44 c is attached to the annular groove formed in the first member 40. The urging member 44c is a spring member formed by bending a metal wire into a C shape, and urges the clutch pawl 44a to the first posture side.

  The connecting portion 52 is provided in a driving force transmission path extending from the driving portion 22 to the hub shell 24. In this embodiment, the connecting portion 52 is provided between the inner peripheral portion of the hub shell 24 and the first member 40 at the second end portion (right end portion in FIG. 2) of the hub shell 24. The connecting portion 52 is provided closer to the second end portion of the hub shell 24 than a bearing support portion 24d of the hub shell 24 described later, and is adjacent to the bearing support portion 24d. As shown in FIG. 3, the connecting portion 52 is an annular member, and has a second serration portion 52 a that engages with the first serration portion 40 e of the first member 40 on the inner peripheral portion. The connecting portion 52 has a fourth serration portion 52 b that engages with the third serration portion 24 c of the hub shell 24 on the outer peripheral surface. The connecting portion 52 has a plurality of holes 52c formed at intervals in the circumferential direction. The hole 52c penetrates the connecting portion in the hub axial direction. The hole 52c is formed as a long hole, and its longitudinal direction is along the circumferential direction. This hole 52c lowers the rigidity of the connecting portion 52 from that of the driving portion 22 and the hub shell 24, and when the driving force (torque) is transmitted from the driving portion 22 to the hub shell 24, the connecting portion 52 is made to respond to the driving force. Provided to facilitate twisting.

<Hub shell>
The hub shell 24 has a structure that can be divided in the axial direction. As shown in FIG. 2, the hub shell 24 is rotatably supported on the shaft main body 30 of the hub shaft 20 by a first bearing 46 at a first end (the left end in FIG. 2). As described above, the second end portion of the hub shell (the right end portion in FIG. 2) is rotatably supported by the shaft body 30 of the hub shaft 20 by the fifth bearing 50 via the drive portion 22. A bearing support portion 24 d to which the fifth outer ring body 50 b of the fifth bearing 50 is attached is provided at the second end portion of the hub shell 24. The bearing support portion 24d is an inner peripheral portion of the hub shell 24 and protrudes toward the hub shaft 20 side. The bearing support portion 24d is formed in an annular shape. The first bearing 46 includes a first inner ring body 46a, a first outer ring body 46b, and a plurality of first rolling elements. The first bearing 46 has a screw formed on the inner peripheral surface thereof, and is screwed into the first male screw portion 30b of the shaft body 30. A moving body 46c. The first rolling elements 46c are rotatably held by a retainer (not shown) and are arranged at a predetermined interval in the circumferential direction. The first rolling element 46c may be a sphere or a roller.

  The fifth bearing 50 includes the above-described fifth inner ring surface 50a, a fifth outer ring body 50b that is press-fitted and fixed to the inner peripheral portion of the second end portion of the hub shell 24, and a plurality of fifth rolling elements 50c. . The fifth rolling element 50c is disposed with a gap in the circumferential direction between the fifth inner ring surface 50a and the fifth outer ring body 50b. The 5th rolling element 50c is rotatably hold | maintained at the retainer which is not shown in figure, and is arrange | positioned at predetermined intervals in the circumferential direction. The fifth rolling element 50c may be a sphere or a roller.

  A first hub flange 24 a and a second hub flange 24 b for connecting the spokes of the rear wheel of the bicycle are formed on the outer peripheral surface of the hub shell 24 so as to project in an annular shape with an interval in the axial direction of the hub shaft 20. A second serration recess 24 c that engages with the outer peripheral surface of the connecting portion 52 is formed on the inner peripheral surface of the first end portion (the right end portion in FIG. 2) of the hub shell 24. An annular partition wall portion 24d for mounting the fifth bearing 50 is formed on the first side of the second serration recess 24c.

<First counter part>
The first facing portion 54 is provided at the first end portion of the first member 40 of the driving portion 22. The 1st opposing part 54 protrudes outward from the outer peripheral part of the 1st member 40, and protrudes from the outer peripheral part of the 3rd cylinder part 40d here. The first facing portion 54 has an arm portion 54 a that extends from the outer peripheral portion of the third cylindrical portion 40 d toward the inner peripheral surface of the hub shell 24. Note that at least one first facing portion 54 is sufficient. The first facing portion 54 is configured separately from the connecting portion 52. The first facing portion 54 extends further outward in the radial direction than the fifth outer ring body 50 b of the fifth bearing 50. The first facing portion 54 is formed integrally with the driving portion 22.

<Second opposing portion>
The second facing portion 56 is provided so as to face the first facing portion 54 at an interval from the first facing portion 54 in the rotational direction of the drive unit 22 and the hub shell 24. The rotation direction of the drive unit 22 and the hub shell 24 is a direction that rotates when the bicycle moves forward. The second facing portion 56 is provided on the downstream side in the rotation direction of the first facing portion 54. The second facing portion 56 is provided close to the bearing support portion 24d of the hub shell 24, and is provided closer to the first end portion of the hub shell 24 than the bearing support portion 24d (the left end portion in FIG. 2). The second facing portion 56 has a protruding portion 56 a that protrudes from the inner peripheral portion of the hub shell 24 toward the driving portion 22. The facing surfaces of the arm portion 54a of the first facing portion 54 and the protruding portion 56a of the second facing portion 56 that face each other in the rotational direction are preferably arranged in parallel. As shown in FIG. 4, the first facing portion 54 and the second facing portion 56 sandwich a plurality of virtual radius lines R extending radially from a central axis C of the hub shaft 20 on a plane perpendicular to the central axis. A plurality are arranged facing each other. FIG. 4 shows a case where there are four virtual radius lines, and shows a case where four first opposing portions 54 and four second opposing portions 56 are provided. The same number of second opposing portions 56 as the first opposing portions 54 are provided. The plurality of pairs of the first facing portion 54 and the second facing portion 56 are preferably provided at positions that are rotationally symmetric about the central axis C of the hub shaft 20. The plurality of first opposing portions 54 are arranged so that the distances from the first opposing portions 54 adjacent in the circumferential direction are equal, and the plurality of second opposing portions 56 are adjacent to the second opposing portion 56 in the circumferential direction. It is preferable to arrange so that the distance to each other becomes equal. The second facing portion 56 is formed integrally with the hub shell 24.

<Driving force measurement unit>
The driving force measuring unit 26 has at least one sensor 58. The sensor 58 can measure the distance between the first facing part 54 and the second facing part 56 or the displacement of the distance. The sensor 58 is, for example, an eddy current type sensor. In this embodiment, the sensor 58 is provided in the first facing portion 54. More specifically, a sensor 58 is provided at the tip of the first facing portion 54 at a portion facing the second facing portion 56.

  The eddy current type sensor 58 uses a high-frequency magnetic field. Specifically, a high frequency current is passed through a coil inside the sensor head to generate a high frequency magnetic field. If there is the second opposing portion 56 in this magnetic field, an eddy current in the direction perpendicular to the passage of magnetic flux flows on the surface of the second opposing portion 56 due to electromagnetic induction action, and depending on the distance from the second opposing portion 56. The impedance of the sensor coil changes. Using this phenomenon, the eddy current sensor 58 outputs a signal indicating the interval between the first opposing portion 54 and the second opposing portion 56 or a signal corresponding to the displacement of the interval. The plurality of sensors 58 are connected in series or in parallel.

<Wireless transmitter>
The wireless transmission unit 28 includes a circuit board 28 b that is fixed to the inner periphery of the hub shell 24. The sensor 58 and the circuit board 28b are electrically connected by a wiring (not shown). The circuit board 28b includes an electronic component such as a microcomputer, an amplifier that amplifies the output from the sensor 58, an AD (Analog-Digital) conversion circuit that converts the signal amplified by the amplifier into a digital signal, and a wireless transmission circuit, and a power source. As a rechargeable battery 28c. In the present embodiment, the microcomputer, the amplifier, and the AD conversion circuit constitute a part of the driving force measuring unit 26.

  The wireless transmission unit 28 wirelessly transmits information based on the output of the sensor 58. Information wirelessly transmitted from the wireless transmission unit 28 is displayed as at least one of driving force, torque, and power by a cycle computer (not shown). Based on the output of the sensor 58, the microcomputer provided on the circuit board 28b may calculate at least one of the driving force, torque, and power. In the cycle computer, the driving force, At least one of torque and power may be calculated. A primary battery may be provided instead of the rechargeable battery 28c. The rechargeable battery 28c or the primary battery is detachably provided on the circuit board 28b.

  In the rear hub 10 configured as described above, when the rider steps on the pedal attached to the bicycle, the pedaling force of the rider is transmitted from the drive unit 22 to the hub shell 24 as a drive force. At this time, the connecting portion 52 is slightly twisted, and the interval between the first facing portion 54 and the second facing portion 56 changes according to the driving force. Specifically, when the driving force increases, the amount of twist of the connecting portion 52 increases, and the first facing portion 54 provided with the sensor 58 approaches the second facing portion 56. Information on the driving force according to the output of the sensor 58 is processed by the wireless transmission unit 28, and the wireless transmission unit 28 wirelessly transmits it to the cycle computer. The cycle computer receives and displays information representing the driving force transmitted wirelessly. Thereby, the rider can know the driving force, torque, power, etc. that he / she is generating.

  Here, since the sensor 58 detects the relative interval between the first opposing portion 54 and the second opposing portion 56 or the displacement of the interval, it is possible to suppress the influence on the measurement result due to how the sensor 58 is attached, It can be made less susceptible to the accuracy of assembly.

Second Embodiment
In 1st Embodiment, although the connection part 52 was comprised separately from the 1st member 40 of the drive part 22, this invention is not limited to this. The connecting portion may be located on the driving portion in the driving force transmission path from the driving portion to the hub shell. In the following description, descriptions of members having the same configuration and shape as those of the first embodiment are omitted.

  As shown in FIG. 5, the rear hub 110 includes a hub shaft 20, a drive unit 122, a hub shell 124, at least one first facing unit 154, at least one second facing unit 156, and a driving force measuring unit 126. And a wireless transmission unit 128 and a generator 160.

  The connecting portion 152 of the driving unit 122 is integrally formed with the first member 140 of the driving unit 122. The 1st member 140 has the 1st cylinder part 140b provided with the recessed part 140a. A first end portion (left end portion in FIG. 5) of the first member 140 extends to the inner peripheral side of the hub shell 124. The 1st member 140 has the 2nd cylinder part 140c larger diameter than the 1st cylinder part 140b in the 1st end part side (left side of Drawing 5) of the 1st cylinder part 140b. The connection part 152 is a cylindrical part formed in the 2nd cylinder part 140c of the 1st member 140 in a diameter smaller than the 2nd cylinder part 140c.

  The distal end portion of the connecting portion 152 is connected to a protrusion 124f protruding inward in the radial direction from the inner peripheral portion of the intermediate portion of the hub shell 124 so as to be integrally rotatable. The protrusions 124f may be formed in an annular shape, or may be formed, for example, at intervals in the circumferential direction. A plurality of holes 152c are formed in the intermediate portion of the connecting portion 152 at intervals in the circumferential direction. The hole 152c is provided so as to penetrate the connecting portion 152. The function of the hole 152c is the same as that of the first embodiment. As shown in FIG. 6, the first facing portion 154 is provided in the vicinity of the bearing support portion 124d. The first facing portion 154 is provided closer to the first end portion of the hub shell 124 than the bearing support portion 124d. An arm portion 154a extending from the outer peripheral surface of the second tube portion 140c toward the hub shell 124 is provided at a boundary portion between the second tube portion 140c and the connecting portion 152. A sensor 158 is provided in the first facing portion 154. The first facing portion 154 is formed integrally with the first member 40.

  The second facing portion 156 has a facing recess 156 a formed to be recessed in the inner peripheral portion of the hub shell 124. The opposing concave portion 156a is formed to be recessed so as to surround the tip portion of the first opposing portion 154. The facing surfaces of the arm portion 154a of the first facing portion 154 and the facing recess 156a of the second facing portion 156 that face each other in the rotational direction are preferably arranged in parallel.

  As shown in FIG. 6, the first facing portion 154 and the second facing portion 156 sandwich a plurality of virtual radius lines R extending radially from the central axis C of the hub shaft 20 on a plane perpendicular to the central axis. A plurality are arranged facing each other. FIG. 6 illustrates a case where there are four virtual radius lines, and illustrates a case where four first opposing portions 154 and four second opposing portions 156 are provided. The same number of second opposing portions 156 as the first opposing portions 154 are provided. The plurality of pairs of the first facing portion 154 and the second facing portion 156 are preferably provided at positions that are rotationally symmetric about the central axis C of the hub shaft 20. The plurality of first opposing portions 154 are arranged so that the distance from the first opposing portion 154 adjacent in the circumferential direction is equal, and the plurality of second opposing portions 156 is the second opposing portion 156 adjacent in the circumferential direction. It is preferable to arrange so that the distance to each other becomes equal.

  The driving force measurement unit 126 includes a sensor 158. In this embodiment, the sensor 158 is provided in the first facing portion 154. More specifically, a sensor 158 is provided at the tip of the first facing portion 154 at a portion facing the second facing portion 56 in the rotational direction. The sensor 158 is an optical sensor. The sensor 158 emits light such as laser light toward the second facing portion 156 and detects the reflected light from the second facing portion 156. By detecting the phase difference between the irradiation light and the reflected light using the sensor 158, the distance between the first facing portion 154 and the second facing portion 156 or the displacement of the distance can be measured. The second facing portion 156 may be provided with a reflecting portion that efficiently reflects the light from the sensor 158. The reflection part may be formed of a paint, or a seal-like member may be attached. The plurality of sensors 58 are connected in series or in parallel.

  The generator 160 is a power source that supplies power to the wireless transmission unit 28 and the sensor 158. The generator 160 includes a magnet 162 that is fixed to the outer peripheral portion of the shaft body 30 of the hub shaft 20 and a rotor 164 that is disposed on the outer peripheral side of the magnet 162 so as to face the magnet 162. The rotor 164 includes a coil bobbin fixed to the inner peripheral portion of the hub shell 124, a coil wound around the coil bobbin, and a yoke disposed around the coil. The output of the coil is rectified to direct current by the wireless transmission unit 28 and used as a power source.

  In the second embodiment as well, as in the first embodiment, the sensor 158 detects the interval between the first opposing portion 154 and the second opposing portion 156 or the displacement of the interval, and therefore is affected by the accuracy of assembly. Can be difficult.

<Third Embodiment>
The third embodiment differs from the first embodiment only in the shape of the first facing portion and the sensor configuration. In the third embodiment, as shown in FIG. 7, the second facing portion 256 provided in the hub shell 224 has the same shape as the first facing portion 54 of the first embodiment shown in FIG. In the third embodiment, the first facing portion 254 is provided on the outer peripheral portion of the annular member 254 a provided in the drive unit 222. The annular member 254 a is provided in the third cylindrical portion 240 d and is formed integrally with the first member 40. The 1st opposing part 254 has the opposing recessed part 254b formed recessed in the cyclic | annular member 254a. The opposing concave portion 254b is formed to be recessed so as to surround the tip portion of the second opposing portion 156. The opposing surfaces of the opposing concave portion 254b of the first opposing portion 154 and the second opposing portion 256 that oppose each other in the rotational direction are preferably arranged in parallel.
As shown in FIG. 7, the first facing portion 254 and the second facing portion 256 sandwich a plurality of virtual radius lines R extending radially from the central axis C of the hub shaft 20 on a plane perpendicular to the central axis. A plurality are arranged facing each other. FIG. 6 shows a case where there are four virtual radius lines, and a case where four first opposing portions 254 and four second opposing portions 256 are provided is shown. The same number of second opposing portions 256 as the first opposing portions 254 are provided. The plurality of pairs of the first facing portion 254 and the second facing portion 256 are preferably provided at positions that are rotationally symmetric about the central axis C of the hub shaft 20. The plurality of first opposing portions 254 are arranged so that the distances between the first opposing portions 254 adjacent in the circumferential direction are equal, and the plurality of second opposing portions 256 are adjacent to the second opposing portion 256 in the circumferential direction. It is preferable to arrange so that the distance to each other becomes equal.

  The driving force measurement unit 226 has a sensor 258. In this embodiment, the sensor 258 is provided in the first facing portion 254. Specifically, the sensor 258 is provided at a portion of the opposing recess 254b of the first opposing portion 254 that faces the second opposing portion 256 in the rotational direction. The sensor 258 is a capacitance type sensor. The sensor 258 includes a first electrode 258a that constitutes the anode of the capacitor, and a second electrode 258b that is disposed opposite to the first electrode 258a and constitutes the cathode of the capacitor. The first electrode 258a is attached to the first facing portion 254. The second electrode 258b is attached to the second facing portion 256 so as to face the first electrode. By using the capacitance type sensor 258, the distance between the first facing portion 254 and the second facing portion 256 or the like using the principle that the distance between the first electrode 258a and the second electrode 258b is inversely proportional to the capacitance or The distance displacement can be measured.

  The plurality of sensors 258 are connected in series as shown in FIG. In FIG. 8, on the circuit board 228b of the driving force measuring unit 226, two coils 228d connected in series arranged in parallel with four sensors 258 connected in series and two coils 228d arranged in parallel are arranged. An npn transistor 228e is provided. The base of the transistor 228e is connected to one end of two coils 228d connected in series, and the collector is connected to the other end of the two coils 228d connected in series. The emitter of the transistor 228e is connected to the intermediate node of two coils 228d connected in series. The sensor 258 and the coil constitute an LC resonance circuit, and the output of the sensor 258 is amplified. When a plurality of sensors 258 are directly connected, it is not necessary to separately provide a signal processing circuit for detecting signals from each sensor, so that the configuration can be simplified and current consumption can be reduced. In addition, since errors in the outputs of the plurality of sensors 258 arranged at different positions are canceled out, it is possible to accurately detect the interval or the displacement of the interval.

  Further, in FIG. 9 according to the modified example of the third embodiment, the four sensors 258 'are connected in parallel. The modification is the same as the configuration of the third embodiment shown in FIG. 8 except that four sensors 258 'connected in parallel and two coils 228d connected in series are connected in parallel.

  When a plurality of sensors 258 'are connected in parallel, it is not necessary to separately provide signal processing circuits for detecting signals from the sensors, so that the configuration can be simplified and the current consumption can be reduced. In addition, since the outputs of a plurality of sensors arranged at different positions are canceled out, it is possible to accurately detect the interval or the displacement of the interval.

  In the third embodiment as well, as in the first and second embodiments, the sensor 258 detects the interval between the first opposing portion 254 and the second opposing portion 256 or the displacement of the interval. Can be less affected.

<Fourth embodiment>
As shown in FIGS. 10 and 11, in the bicycle rear hub 310 according to the fourth embodiment, the driving force of the driving portion 322 is applied to the hub shell 324 via the connecting portion 352 as in the first embodiment shown in FIG. 2. Communicated. The sensors 358 of the driving force measuring unit 326 are provided on the four first opposing portions 354, respectively. As shown in FIG. 12, the sensor 358 includes a coil 358a formed on a substrate 358b. The four coils 358a are connected in series as shown in FIG. Output signals from the four coils 358 a connected in series are processed by the signal processing unit 327 and output to the wireless transmission unit 328. The signal processing unit 327 includes an oscillation circuit 327a, a signal processing circuit 327b, and a communication circuit 327c. The oscillation circuit 327a oscillates the output from the coil 358a. The oscillation circuit 327 is realized by an LC oscillation circuit, for example. The oscillation circuit 327 may include a coil 358a. The signal processing circuit 327b converts the signal oscillated by the oscillation circuit 327 into serial data and outputs the serial data to the wireless transmission unit 328 via the communication circuit 327c. The wireless transmission unit 328 includes a control unit 328a including a microcomputer. The wireless transmission unit 328 wirelessly transmits a signal indicating the driving force processed by the signal processing unit 327. In the fourth embodiment, the signal processing unit 327 is disposed inside the hub shell 324 as shown in FIG. The wireless transmission unit 328 is disposed outside the hub shell 324 and is covered with a cover. The cover is made of a material that transmits radio waves, for example, synthetic resin. Similarly to the wireless transmission unit 328, the signal processing unit 327 may be disposed outside the hub shell 324, and the signal processing unit 327 and the wireless transmission unit 328 may be formed on one substrate.

  In the fourth embodiment, since the sensor 358 is configured by connecting four coils 358a in series, the configuration can be simplified and the current consumption can be reduced. In addition, since errors in the outputs of the plurality of sensors 258 arranged at different positions are canceled out, it is possible to accurately detect the interval or the displacement of the interval.

  As shown in FIG. 14, the first modification of the fourth embodiment is different from the fourth embodiment in that four coils 358a 'are connected in parallel. When the four coils 358a 'are connected in parallel, it is not necessary to separately provide a signal processing circuit for detecting a signal from each sensor, so that the configuration can be simplified and current consumption can be reduced. In addition, since the outputs of a plurality of sensors arranged at different positions are canceled out, it is possible to accurately detect the interval or the displacement of the interval.

  As shown in FIG. 15, the second modification of the fourth embodiment is different from the fourth embodiment in that a coil 358 a configuring the sensor 358 is provided not in the first opposing portion 354 but in the second opposing portion 356. Thereby, since the coil 358a is provided in the same hub shell 324 as the signal processing unit 327, wiring between the coil 358a and the signal processing unit 327 is facilitated.

<Fifth Embodiment>
As shown in FIG. 16, the bicycle rear hub 10 according to the fifth embodiment can be mounted on a hub axle mounting portion 102 provided at the rear portion of the bicycle frame. The rear hub 10 includes a hub shaft 20, a drive unit 22, a hub shell 24, a drive force measurement unit 26, and a wireless transmission unit 28. The hub shell 24 is rotatably supported on the hub shaft 20 by a first bearing 46. The drive unit 22 is rotatably supported by the hub shaft 20 by the second bearing 47. The driving force measuring unit 26 can measure the driving force of the rider. The wireless transmission unit 28 wirelessly transmits information regarding the measured driving force. The information on the driving force transmitted wirelessly is displayed on a cycle computer (not shown) that can be mounted on a bicycle handle, for example. The cycle computer also displays information such as bicycle speed, crank rotation speed (cadence), and travel distance.

<Hub shaft>
The hub shaft 20 includes a hollow shaft body 30 to which the quick release mechanism 29 is attached, a first lock nut 32 to be attached to a first end portion (left end portion in FIG. 16) of the shaft body 30, and a shaft body. 30 and a second lock nut 34 attached to the second end portion (the end portion on the right side of FIG. 16). The hub shaft mounting portion 102 can be mounted on the first lock nut 32 and the second lock nut 34. Here, the configuration in which the first lock nut 32 and the second lock nut 34 are mounted on the hub shaft mounting portion 102 is described, but the shaft main body 30 may be mounted on the hub shaft mounting portion 102 of the frame. Good.

  As shown in FIG. 17, a female screw portion 30 a is formed on the inner peripheral surface of the first end portion of the shaft body 30. A first male screw portion 30b and a second male screw portion 30c are formed on the outer peripheral surfaces of the first and second end portions of the shaft body 30, respectively. The first lock nut 32 has a male screw portion that is screwed into the female screw portion 30 a, and is screwed and fixed to the shaft main body 30. The second lock nut 34 has a female screw portion that is screwed into the second male screw portion 30 c, and is screwed and fixed to the shaft main body 30.

<Driver>
The drive unit 22 includes a so-called free wheel. The drive unit 22 includes a first member 40 that is rotatably supported by the hub shaft 20, a second member 42 that is disposed on the outer peripheral side of the first member 40, and a space between the first member 40 and the second member 42. A one-way clutch 44, a connecting part 52, and a measured part 53. The first member 40 is an example of an inner cylindrical part, and the second member 42 is an example of an outer cylindrical part.

  The first member 40 is a cylindrical member that is rotatably supported by the hub shaft 20 by the second bearing 47. Here, the first member 40 is formed in a cylindrical shape. The second bearing 47 includes a second inner ring body 47a, a second outer ring body 47b, and a plurality of second rolling elements 47c. The second inner ring body 47 a has a screw formed on the outer peripheral portion thereof, and is fixed by being screwed into the second male screw portion 30 c of the shaft body 30. The second outer ring body 47 b has a screw formed on the inner peripheral portion thereof, and is screwed and fixed to a male screw portion formed on the outer peripheral surface of the first member 40. The plurality of second rolling elements 47c are provided between the second inner ring body 47a and the second ball receiver 47b at intervals in the circumferential direction. The second rolling elements 47c are rotatably held by a retainer (not shown) and are arranged at a predetermined interval in the circumferential direction. The second rolling element 47c may be a sphere or a roller.

  The first member 40 has a first tube portion 40b having a recess 40a in which the clutch pawl 44a of the one-way clutch 44 is accommodated. A first end portion (left end portion in FIG. 17) of the first member 40 extends to the inner peripheral side of the hub shell 24. The 1st member 40 has the 2nd cylinder part 40c in the 1st end part side (left side of Drawing 17) of the 1st cylinder part 40b. The 2nd cylinder part 40c has a diameter larger than the diameter of the 1st cylinder part 40b. The 2nd cylinder part 40c and the 1st cylinder part 40b may have the same diameter. The second outer ring body 47b of the second bearing 47 is fixed to the second end portion (right end portion in FIG. 17) of the first tube portion 40b. A third inner ring surface 48a constituting the third bearing 48 is formed on the outer peripheral surface of the boundary portion between the first tube portion 40b and the second tube portion 40c. A fifth inner ring surface 50a of a fifth bearing 50 for rotatably supporting the hub shell 24 on the drive unit 22 is formed on the outer peripheral surface of the second cylindrical portion 40c.

  The second member 42 is a cylindrical member that is rotatably supported with respect to the first member 40 by the third bearing 48 and the fourth bearing 49. Here, the second member 42 is formed in a cylindrical shape. The third bearing 48 is formed by the above-described third inner ring surface 48a, third outer ring surface 48b, and a plurality of third rolling elements 48c. The third outer ring surface 48 b is formed on the inner peripheral surface of the first end portion (the left end portion in FIG. 2) of the second member 42. The plurality of third rolling elements 48c are provided between the third inner ring surface 48a and the third outer ring surface 48b at intervals in the circumferential direction. The 3rd rolling element 48c is rotatably hold | maintained at the retainer which is not shown in figure, and is arrange | positioned at predetermined intervals in the circumferential direction. The third rolling element 48c may be a sphere or a roller.

  The fourth bearing 49 is formed by a fourth inner ring surface 49a formed on the outer peripheral surface of the second outer ring body 47b, a fourth outer ring surface 49b, and a plurality of fourth rolling elements 49c. The fourth outer ring surface 49b is formed on the inner peripheral surface of the intermediate portion of the second member 42 in the hub axial direction. The plurality of fourth rolling elements 49c are provided between the fourth inner ring surface 49a and the fourth outer ring surface 49b at intervals in the circumferential direction. The 4th rolling element 49c is rotatably hold | maintained at the retainer which is not shown in figure, and is arrange | positioned at predetermined intervals in the circumferential direction. The fourth rolling element 49c may be a sphere or a roller.

  As shown in FIG. 16, the second member 42 has a sprocket mounting portion 42a for mounting the sprocket assembly 80 on the outer peripheral surface. The sprocket assembly 80 is an example of a driving force transmission member. The sprocket assembly 80 rotates integrally with the second member 42. The sprocket assembly 80 is an example of a driving force transmission member. The sprocket mounting part 42a has, for example, a spline having a convex part or a concave part arranged on the outer peripheral part at intervals in the circumferential direction. The sprocket assembly 80 has a plurality of (for example, nine) sprockets 80a to 80i having different numbers of teeth. The rotation of the crank (not shown) is transmitted to the drive unit 22 by the chain 81 that meshes with any one of the sprocket assemblies 80. Here, although a plurality of sprockets are mounted on the sprocket mounting portion 42a, the number of sprockets mounted on the sprocket mounting portion 42a may be one.

  The one-way clutch 44 is provided to transmit only the rotation of the second member 42 in the traveling direction of the bicycle to the first member 40. Thereby, only the rotation of the crank in the traveling direction is transmitted to the hub shell 24. Further, the rotation of the hub shell 24 in the traveling direction is not transmitted to the second member 42. The one-way clutch 44 biases the clutch pawl 44a provided in the recess 40a so as to be swingable in the first posture and the second posture, the ratchet teeth 44b formed on the inner peripheral surface of the second member 42, and the clutch pawl 44a. Biasing member 44c. The clutch pawl 44a comes into contact with the ratchet teeth 44b in the first posture and disengages from the ratchet teeth 44b in the second posture. The urging member 44 c is attached to the annular groove formed in the first member 40. The urging member 44c is a spring member formed by bending a metal wire into a C shape, and urges the clutch pawl 44a to the first posture side.

  The connecting portion 52 is connected to the hub shell 24 and is provided in a driving force transmission path extending from the driving portion 22 to the hub shell 24. In this embodiment, the connecting portion 52 is an intermediate portion in the axial direction of the hub shell 24 and is provided between the inner surface of the hub shell 24 and the measured portion 53. The connection part 52 has the external thread part 52a on an outer peripheral surface. The male screw portion 52a is screwed into a female screw portion 24g formed on the inner peripheral surface of an annular protrusion 24f described later of the hub shell 24. Accordingly, the connecting portion 52 is screwed and fixed to the hub shell 24. The hub shell 24 and the connecting portion 52 may be further coupled by a retaining member (not shown) that prevents the hub shell 24 and the connecting portion 52 from rotating around the hub axis. The retaining member may be formed by a cylindrical bolt. In this case, an internal thread is formed on the inner peripheral surface of the end portion of the connecting portion 52, and between the head portion of the bolt and the connecting portion 52, The projection 24f is partly sandwiched. Alternatively, a nut may be formed. In this case, a female screw is formed on the outer peripheral surface of the end portion of the connecting portion 52, and a part of the protrusion 24 f is sandwiched between the nut and the connecting portion 52.

  The measured portion 53 is provided for driving force measurement, and is integrally formed with the first member 40b. The measured portion 53 extends from the second cylindrical portion 40c of the first member 40b toward the connecting portion 52. The part to be measured 53 is formed in a cylindrical shape, and here is formed in a cylindrical shape. The measured portion 53 has a diameter smaller than the diameter of the second cylinder portion 40c. The measured portion 53 is formed integrally with the connecting portion 52.

<Hub shell>
As shown in FIG. 17, the hub shell 24 is rotatably supported on the shaft body 30 of the hub shaft 20 by the first bearing 46 at the first end (the left end in FIG. 17). As described above, the second end portion of the hub shell (the right end portion in FIG. 17) is rotatably supported by the shaft body 30 of the hub shaft 20 by the fifth bearing 50 via the drive portion 22. The fifth outer ring body 50 b of the fifth bearing 50 is attached to the second end portion of the hub shell 24. The first bearing 46 includes a first inner ring body 46a, a first outer ring body 46b, and a plurality of first rolling elements. The first bearing 46 has a screw formed on the inner peripheral surface thereof, and is screwed into the first male screw portion 30b of the shaft body 30. A moving body 46c. The first rolling elements 46c are rotatably held by a retainer (not shown) and are arranged at a predetermined interval in the circumferential direction. The first rolling element 46c may be a sphere or a roller.

  The fifth bearing 50 includes the above-described fifth inner ring surface 50a, a fifth outer ring body 50b that is press-fitted and fixed to the inner peripheral portion of the second end portion of the hub shell 24, and a plurality of fifth rolling elements 50c. . The fifth rolling element 50c is disposed with a gap in the circumferential direction between the fifth inner ring surface 50a and the fifth outer ring body 50b. The 5th rolling element 50c is rotatably hold | maintained at the retainer which is not shown in figure, and is arrange | positioned at predetermined intervals in the circumferential direction. The fifth rolling element 50c may be a sphere or a roller.

  A first hub flange 24 a and a second hub flange 24 b for connecting the spokes of the rear wheel of the bicycle are formed on the outer periphery of the hub shell 24 so as to protrude annularly with an interval in the axial direction of the hub shaft 20. A protrusion 24 f that engages with the outer peripheral surface of the coupling portion 52 is formed on the inner peripheral surface of the intermediate portion in the axial direction of the hub shell 24. A female screw portion 24g that is screwed into the male screw portion 52a is formed on the inner peripheral surface of the protrusion 24f. The hub shell 24 may have a structure that can be partly divided for assembly. In the present embodiment, the protrusion 24f is formed at the center portion of the hub shell 24 in the hub axial direction.

<Driving force measurement unit>
The driving force measuring unit 26 has at least one sensor 58. The sensor 58 can measure the amount of twist of the measurement target portion 53. The sensor 58 is a semiconductor sensor capable of detecting a strain gauge or strain, for example. The sensor 58 is fixed to the measured portion 53 by an appropriate fixing means such as adhesion. The sensor 58 is provided on the outer peripheral surface of the measurement target portion 53. The sensors 58 are provided, for example, at a plurality of locations (for example, 4 locations) at intervals in the circumferential direction. When a strain gauge is used as the sensor 58, a plurality of strain gauges are provided at the location where each sensor 58 is disposed, and each strain gauge detects strains in directions different from each other, for example, in directions different by 90 °. Each strain gauge detects strain in a direction inclined with respect to the axial direction of the rear hub 10, for example, in a direction inclined 45 °. In addition, the strain gauge 58 in each arrangement | positioning location is connected in bridge shape so that noise may be canceled.

<Wireless transmitter>
The wireless transmission unit 28 includes a circuit board 28 b that is fixed to the inner peripheral portion or the outer peripheral portion of the hub shell 24. The sensor 58 and the circuit board 28b are electrically connected by a wiring (not shown). The circuit board 28b includes an electronic component such as a microcomputer, an amplifier that amplifies the output from the sensor 58, an AD (Analog-Digital) conversion circuit that converts the signal amplified by the amplifier into a digital signal, and a wireless transmission circuit, and a power source. As a rechargeable battery 28c. In the present embodiment, the microcomputer, the amplifier, and the AD conversion circuit constitute a part of the driving force measuring unit 26.

  The wireless transmission unit 28 wirelessly transmits information based on the output of the sensor 58. Information wirelessly transmitted from the wireless transmission unit 28 is displayed as at least one of driving force, torque, and power by a cycle computer (not shown). Based on the output of the sensor 58, the microcomputer provided on the circuit board 28b may calculate at least one of the driving force, torque, and power. In the cycle computer, the driving force, At least one of torque and power may be calculated. A primary battery may be provided instead of the rechargeable battery 28c. The rechargeable battery 28c or the primary battery is detachably provided on the circuit board 28b.

  In the rear hub 10 configured as described above, when the rider steps on the pedal attached to the bicycle, the pedaling force of the rider is transmitted from the drive unit 22 to the hub shell 24 as a drive force. At this time, the measured portion 53 is slightly twisted, and the amount of twist changes according to the driving force. Specifically, when the driving force increases, the torsion amount of the measured portion 53 increases. The output of the sensor 58 changes in accordance with the amount of twist of the measured part 53. Information on the driving force according to the output of the sensor 58 is processed by the wireless transmission unit 28, and the wireless transmission unit 28 wirelessly transmits it to the cycle computer. The cycle computer receives and displays information representing the driving force transmitted wirelessly. Thereby, the rider can know the driving force, torque, power, etc. that he / she is generating.

  Here, the first portion 40 and the measured portion 53 are integrally configured, and the driving force measuring portion 26 measures the first portion 40 and the measured portion 53 as compared to a case where the first portion 40 and the measured portion 53 are configured separately. Noise can be reduced, and the torsional bias of the part to be measured is less likely to occur, so that the measurement accuracy can be improved and the gravity can be reduced.

  In the fifth embodiment, the connecting portion 52 is arranged in the intermediate portion of the hub shell 24 in the axial direction. However, in the rear hub 110 of the modification shown in FIG. 18, the connecting portion 152 having the male screw portion 152 a is the first end of the hub shell 124. Part (left end part in FIG. 18). A protrusion 124f having an internal thread portion 124g is formed on the first end portion side of the hub shell 124. Here, since the axial length of the driving force measuring unit 153 becomes longer, the twist of the driving force measuring unit 153 can be made larger than in the above-described embodiment, and the strain detection sensitivity compared to the above embodiment. Can be used.

<Sixth Embodiment>
In the fifth embodiment, the strain gauge is used as a sensor for measuring the twist of the driving force measuring unit 26, but the present invention is not limited to this.

  In the rear hub 210 of the sixth embodiment shown in FIG. 19, the sensor 258 of the driving force measuring unit 226 includes a magnetostrictive element 258a provided in the driving force measuring unit 253, and a detection coil 258b disposed on the outer peripheral side of the magnetostrictive element 258a. Have. Other configurations are the same as those of the fifth embodiment described above. A pair of magnetostrictive elements 258a are provided so that the magnetostrictive directions are orthogonal. The detection coils 258b are respectively provided at positions facing the respective magnetostrictive elements 258a, and output signals corresponding to the twist generated in the magnetostrictive elements 258a.

  When the twist is detected by such a magnetostrictive element 258a, the amount of twist of the measured portion 53 can be detected with high accuracy.

<Other embodiments>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.

  (A) In the said embodiment, although the drive part 22 was comprised including the so-called free hub which has a one-way clutch in the said embodiment, this invention is not limited to this. For example, the present invention can be applied to a rear hub that does not have a free hub.

  (B) In the above embodiment, the rear hub having the quick release mechanism 29 has been exemplified. However, the present invention can also be applied to a rear hub having no quick release mechanism.

  (C) In the above embodiment, the sensor is disposed in the first facing portion 54, but the sensor may be disposed in the second facing portion.

  (D) In the first embodiment, an eddy current sensor is exemplified as the sensor 58, in the second embodiment, an optical sensor is exemplified, and in the third embodiment, a capacitance sensor is exemplified. However, the present invention is not limited to this. The sensor may be any sensor as long as it can measure the distance between the first facing portion and the second facing portion or the displacement of the distance. For example, an ultrasonic sensor may be used.

  For example, the sensor of the first embodiment may be an optical sensor or a capacitance sensor, and the sensor of the second embodiment may be an eddy current sensor or a capacitance sensor. The sensor according to the third embodiment may be an optical sensor or an eddy current sensor.

  (E) In the said embodiment, although the generator and the rechargeable battery were illustrated as a power supply, this invention is not limited to this. For example, a storage element such as a chargeable capacitor may be used. Moreover, you may use the primary battery which cannot be charged as a power supply.

  (F) In 2nd Embodiment, although the generator 60 is used for the electric power supply of the sensor 58 and the wireless transmission part 28, this invention is not limited to this. The wireless transmission unit may detect the AC power waveform output from the generator 60 to obtain the rotation speed signal of the rear hub. The power may be calculated by a microcomputer using the obtained information on the rotational speed signal and the torque that is the driving force measured by the driving force measuring unit. In addition, the wireless transmission unit transmits information on the rotation speed signal to the cycle computer, and by multiplying the circumference of the rear wheel, it can be used for vehicle speed display on the cycle computer.

  (G) In the said embodiment, although the hole which penetrates a connection part is formed in a connection part, a recess may be formed instead of the hole which penetrates, and it is good also as a structure which does not provide a hole.

  (H) The first facing portion and the second facing portion of the first embodiment may be changed to the first facing portion and the second facing portion of the second or third embodiment. You may change the 1st opposing part and 2nd opposing part of 2nd Embodiment into the 1st opposing part and 2nd opposing part of 1st or 3rd embodiment. You may change the 1st opposing part and 2nd opposing part of 3rd Embodiment into the 1st opposing part and 2nd opposing part of 1st or 2nd embodiment.

  (I) In the above-described embodiment, the portion of the second facing portion 56 facing the sensor is provided on the downstream side in the rotation direction of the first facing portion, but the portion of the second facing portion 56 facing the sensor is You may provide in the upstream of the rotation direction of 1 opposing part. When the driving force increases, the amount of twist of the connecting portion 52 increases, and the first facing portion where the sensor is provided is separated from the portion facing the sensor of the second facing portion. Even in this case, it is possible to detect a relative interval between the first opposing portion and the second opposing portion or a displacement of the interval.

  (J) In the said embodiment, although the 1st member 40 is provided with the some cylindrical part from which a diameter differs, the structure which is not provided with the some cylindrical part from which a diameter differs may be sufficient. The shape of the 1st member 40 can be suitably changed according to the form of a bearing.

  (K) In the above embodiment, any one or more of the first to fifth bearings may be changed to a sliding bearing. In this case, the weight can be reduced.

  (L) In the said embodiment, you may comprise the part which comprises a free wheel among 1st members so that attachment or detachment is possible from another part. If comprised in this way, a freewheel can be exchanged freely. The detachable portion of the first member may be coupled to another portion by a connection mechanism such as serration.

  (M) In the fifth and sixth embodiments, the connecting portion and the hub shell are connected by screwing connection. However, as in the first to fourth embodiments, the connecting portion and the hub shell may be connected by serration. Good. Conversely, in the first to fourth embodiments, the connecting portion and the hub shell may be connected by screwed connection instead of serration.

  (N) In the fifth and sixth embodiments, a battery is provided as a power source, but a generator as shown in FIG. 5 may be provided instead of the battery.

10, 110, 210, 310 Rear hub 20 Hub shaft 22, 122, 222, 322 Driving unit 24, 124, 224, 324 Hub shell 26, 126, 226, 326 Driving force measuring unit 28 Radio transmitting unit 42a Sprocket mounting unit 52, 152 , 352 Connecting portion 54, 154, 254 First opposing portion 54a Arm portion 56, 156, 256 Second opposing portion 56a Protruding portion 58, 158, 258, 258 ', 358, 358' Sensor 60 Generator 80 Sprocket assembly 258a Magnetostrictive element 258b detection coil

Claims (35)

A bicycle rear hub,
A hub axle,
A drive unit rotatably supported by the hub shaft and capable of mounting a drive force transmission member;
A hub shell that is rotatably supported by the hub shaft and to which rotation of the drive unit is transmitted;
At least one first facing portion provided in the driving unit;
At least one second facing portion provided on the hub shell and capable of facing the first facing portion at an interval;
A driving force measuring unit having at least one sensor capable of measuring a distance between the first facing part and the second facing part or a displacement of the distance;
Rear hub for bicycles equipped with.   2. The bicycle rear hub according to claim 1, wherein the first facing portion and the second facing portion are opposed to each other in a rotation direction of the driving portion and the hub shell.   The bicycle rear hub according to claim 1, wherein the first facing portion protrudes from an outer peripheral portion of the drive portion.   The bicycle rear hub according to any one of claims 1 to 3, wherein the second facing portion protrudes from an inner peripheral portion of the hub shell.   The bicycle rear hub according to any one of claims 1 to 4, wherein the drive unit includes a coupling unit coupled to the hub shell.   The bicycle rear hub according to claim 5, wherein the connecting portion is provided integrally with the first facing portion.   The bicycle rear hub according to claim 5, wherein the connecting portion is provided separately from the first facing portion.   The bicycle rear hub according to claim 7, wherein the connecting portion is formed in an annular shape and has a plurality of through holes extending in a hub axial direction.   The bicycle rear hub according to any one of claims 5 to 8, wherein the connecting portion and the hub shell are coupled by serration or adhesion.   The bicycle rear hub according to any one of claims 5 to 9, wherein the connecting portion and the hub shell are connected at a central portion of the hub shell in the hub axial direction.   The bicycle rear hub according to any one of claims 1 to 10, wherein a plurality of sets of the first facing portion and the second facing portion are provided.   The bicycle rear hub according to claim 111, wherein a plurality of the sensors are provided in at least one of a plurality of sets of the first opposing portions and a plurality of the second opposing portions.   The bicycle rear hub according to claim 12, wherein the plurality of sensors are provided in the first facing portion.   The bicycle rear hub according to claim 12, wherein the plurality of sensors are provided in the second facing portion.   The sensor is provided in the first opposing portion in at least any one of the plurality of first opposing portions and the second opposing portions, and in at least one of the pairs in the second opposing portion. The bicycle rear hub according to claim 12, wherein the sensor is provided.   The bicycle rear hub according to any one of claims 11 to 15, wherein the plurality of sensors are eddy current sensors.   The bicycle rear hub according to any one of claims 11 to 15, wherein the plurality of sensors are capacitive sensors.   The bicycle rear hub according to claim 17, wherein the plurality of capacitive sensors include capacitors.   The bicycle rear hub according to any one of claims 11 to 15, wherein the plurality of sensors are optical sensors.   The bicycle rear hub according to any one of claims 11 to 15, wherein the plurality of sensors are sensors having coils.   The bicycle rear hub according to any one of claims 11 to 20, wherein the plurality of sensors are connected in series.   The bicycle rear hub according to any one of claims 11 to 20, wherein the plurality of sensors are connected in parallel.   The bicycle rear hub according to any one of claims 1 to 22, further comprising a wireless transmission unit that wirelessly transmits information based on the output of the sensor to the outside.   The bicycle rear hub according to any one of claims 1 to 23, further comprising a power source that supplies electric power to the sensor.   The bicycle rear hub according to claim 24, wherein the power source is a battery.   The bicycle rear hub according to claim 24, wherein the power source is a generator. A bicycle rear hub,
A hub axle,
A drive unit rotatably supported by the hub shaft and capable of mounting a drive force transmission member;
A hub shell that is rotatably supported by the hub shaft and to which rotation of the drive unit is transmitted;
A driving force measuring unit capable of measuring a driving force transmitted from the driving unit to the hub shell,
The drive unit is
An outer cylindrical portion to which the driving force transmission member is mounted;
An inner cylindrical portion disposed inside the outer cylindrical portion;
A bicycle rear hub comprising the measured portion provided with the driving force measuring portion and integrally formed with the inner cylindrical portion.   The bicycle rear hub according to claim 27, wherein the inner cylindrical portion and the outer cylindrical portion constitute a one-way clutch. The drive unit further includes a connection part connected to the hub shell,
The bicycle rear hub according to claim 27 or 28, wherein the connecting portion is connected to the inside of the hub shell.   30. The bicycle rear hub according to claim 29, wherein the connecting portion is connected to an axially intermediate portion of the hub shell.   The bicycle rear hub according to claim 29 or 30, wherein the portion to be measured is provided between the connecting portion and the inner cylindrical portion.   The bicycle rear hub according to any one of claims 29 to 31, wherein the driving force measurement unit is disposed inside the hub shell.   The bicycle rear hub according to any one of claims 29 to 32, wherein the connecting portion is screwed and fixed to the hub shell.   The bicycle rear hub according to any one of claims 29 to 33, wherein the driving force measuring unit includes at least one strain gauge. The driving force measuring unit is
A magnetostrictive element disposed on the outer peripheral surface of the measured part;
A detection coil disposed on the inner peripheral surface of the hub shell so as to face the magnetostrictive element;
The bicycle rear hub according to any one of claims 29 to 33, comprising:

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