JP7651390B2 - Torque Meters and Measurement Systems - Google Patents

Description

The present invention relates to a technology for measuring the torque transmitted by a rotating shaft.

As a technique for measuring the torque transmitted by a rotating shaft, a torque meter 9 shown in FIG. 10a is known (for example, see Patent Document 1).
FIG. 10a is a side view of the torque meter 9 with a part cut away, and the hatched area represents the cross section after cutting away.
As shown in the figure, the torque meter 9 has a drive side flange 92 at one axial end of a hollow cylindrical body 91, and a load side flange 93 at the other axial end. The central portion of the hollow body 91 in the axial direction is thin-walled, and a strain gauge 94 is fixed to the thin-walled portion of the inner peripheral surface of the hollow body 91.

As shown in FIG. 10b, the flange 101 of the drive side rotating shaft 100 is fastened to the drive side flange portion 92 of the torque meter 9 by bolts, and the flange 111 of the load side rotating shaft 110 is fastened to the load side flange portion 93 by bolts.

In such a torque meter 9, the torque transmitted between the drive side rotating shaft 100 and the load side rotating shaft 110 is measured by the strain gauge 94 as the distortion of the thin-walled portion of the inner surface of the hollow body portion 91.

JP 2005-321335 A

The torque meter 9 shown in Figures 10a and 10b has the problem that hysteresis occurs in the measurement, and the characteristics of the hysteresis change depending on the rigidity of the flange 101 of the drive side rotating shaft 100 and the rigidity of the flange 111 of the load side rotating shaft 110.

F1 and F2 in Figure 11a show an example of the load torque-error characteristics when the load torque applied to the torque meter is changed continuously from 0 to a specified positive value, from the specified positive value to a specified negative value, and from the specified negative value to 0, and hysteresis is generated.

In Figure 11a, F1 shows the characteristics when the flange thickness is thinner than F2, and as shown in Figures 10b and 10c, if the thickness d1 of flange 101 and the thickness d2 of flange 111, which are factors related to rigidity, differ, the hysteresis characteristics that occur will be different.

Figure 11b shows an example of the flange thickness-sensitivity characteristics, and as shown in Figures 10b and 10c, if the thickness d1 of flange 101 and the thickness d2 of flange 111, which are elements related to rigidity, differ, the sensitivity of the torque meter measurement will differ. Note that Figure 11b shows the flange thickness-sensitivity characteristics with the sensitivity set to 0 when the flange thickness is a predetermined reference thickness.

As such, the torque meter 9 shown in Figures 10a and 10b has the problem that the sensitivity changes depending on the rigidity of the flange 101 of the drive side rotating shaft 100 and the rigidity of the flange 111 of the load side rotating shaft 110.

Such measurement hysteresis and changes in sensitivity and hysteresis characteristics depending on the flange rigidity of the rotating shaft to be fastened have been obstacles to high-precision torque measurement in torque meters.
An object of the present invention is to perform torque measurement with higher accuracy.

In order to achieve the above object, the present invention provides a torque meter for detecting torque, which includes a first disk portion connected by a bolt to a first flange, which is the flange of a first rotating shaft, a second disk portion connected by a bolt to a second flange, which is the flange of a second rotating shaft, a strain-generating portion connecting the first disk portion and the second disk portion, and a strain detection means for detecting strain generated in the strain-generating portion. However, at least a part of the area around the bolt hole or screw hole through which the bolt connecting the first disk portion and the first flange is inserted on the surface of the first disk portion that faces the first flange when the first flange is connected has a shape that protrudes in the direction of the first flange so that the only place where the first disk portion and the first flange abut in the axial direction when the first flange is connected is the part in question.

In such a torque meter, at least a portion of the area around the bolt hole or screw hole through which the bolt connecting the second disk portion to the second flange is inserted on the surface of the second disk portion that faces the second flange when the second flange is connected may be shaped to protrude toward the second flange so that the only place where the second disk portion and the second flange abut in the axial direction when the second flange is connected is the portion.

In order to achieve the above object, the present invention provides a measurement system including a first rotating shaft, a second rotating shaft, and a torque meter that detects torque transmitted between the first rotating shaft and the second rotating shaft, the torque meter including a first disk portion, a second disk portion, a strain-generating portion that connects the first disk portion and the second disk portion, and a strain detection means that detects strain generated in the strain-generating portion. A first flange that is a flange that is connected to the first disk portion by a bolt is provided at an end of the first rotating shaft, and a second flange that is a flange that is connected to the second disk portion by a bolt is provided at an end of the second rotating shaft, and at least a part of the area around the bolt hole or screw hole through which the bolt that connects the first disk portion is inserted on the surface of the first flange that faces the first disk portion is shaped to protrude toward the first disk portion so that the only place where the first flange and the first disk portion come into contact in the axial direction is the said part.

In this measurement system, at least a portion of the area around the bolt hole or screw hole through which the bolt that connects the second disk portion is inserted on the surface of the second flange facing the second disk portion may be shaped to protrude toward the second disk portion so that the only place where the second flange and the second disk portion abut in the axial direction is the said portion.

To achieve the above object, the present invention provides a measurement system including a first rotating shaft, a second rotating shaft, and a torque meter that detects torque transmitted between the first rotating shaft and the second rotating shaft, the torque meter including a first disk portion, a second disk portion, a strain-generating portion that connects the first disk portion and the second disk portion, and a strain detection means that detects strain generated in the strain-generating portion. Also, a first flange that is a flange that is connected to the first disk portion with a bolt is provided on an end of the first rotating shaft, and a second flange that is a flange that is connected to the second disk portion with a bolt is provided on an end of the second rotating shaft. The measurement system is also provided with a first annular member, which is an annular member having a hole, and the first annular member is disposed between the first flange and the first disk portion so that the first flange and the first disk portion do not directly contact each other in the axial direction, and the first flange and the first disk portion are connected by passing a bolt connecting the first flange and the first disk portion through a hole in the first annular member between the first flange and the first disk portion.

In such a measurement system, a second annular member, which is an annular member having a hole, may be provided, and the second annular member may be disposed between the second flange and the second disk portion so that the second flange and the second disk portion do not directly contact each other in the axial direction, and the second flange and the second disk portion may be connected by passing a bolt connecting the second flange and the second disk portion through a hole in the second annular member between the second flange and the second disk portion.

According to the torque meter and measurement system described above, the points where the first disk and first flange abut in the axial direction and the points where the second disk and second flange abut in the axial direction are concentrated in small areas around the bolt, so that changes in stress distribution according to differences in the thickness and rigidity of the first flange and second flange and the magnitude of the applied torque can be suppressed. This makes it possible to keep the measurement hysteresis of the torque meter small, and suppress changes in measurement hysteresis and measurement sensitivity due to differences in the thickness and rigidity of the first flange and second flange, thereby achieving high-precision torque measurement.

As described above, the present invention makes it possible to perform torque measurements with higher accuracy.

1 is a diagram showing a configuration of a torque measuring device and a measurement system according to an embodiment of the present invention; FIG. 1 is a diagram showing a torque meter according to an embodiment of the present invention. FIG. 2 is a diagram showing a configuration for detecting rotation of a torque measuring device according to an embodiment of the present invention. FIG. 2 is a diagram showing a structure for coupling a rotating shaft to a torque meter according to an embodiment of the present invention. FIG. 2 is a diagram showing the periphery of a bolt hole of the torque meter according to the embodiment of the present invention. 1 is a diagram showing the periphery of a screw hole and a through hole of a torque meter according to an embodiment of the present FIG. 11 is a diagram showing another configuration example of a torque meter according to an embodiment of the present invention. FIG. 11 is a diagram showing another configuration example of a torque meter according to an embodiment of the present invention. FIG. 11 is a diagram showing another configuration example of a torque meter according to an embodiment of the present invention. FIG. 1 shows a known torque meter. FIG. 1 illustrates a problem to be solved by the present invention.

An embodiment of the present invention will be described.
FIG. 1a shows the configuration of a torque measuring device according to this embodiment.
In FIG. 1a, FIG. 1a1 shows a front view of the torque measuring device, FIG. 1a2 shows a side view of the torque measuring device, and FIG. 1a3 shows a rear view of the torque measuring device.
As shown in the figure, the torque measuring device is composed of a torque meter 1 and a stator 2. The stator 2 has an annular ring portion 21.
Using the torque measuring device, for example, a measurement system as shown in FIG. 1b is constructed.
1b, a first flange 31 which is a flange provided at an end of a first rotating shaft 3 is connected to the front side of the torque meter 1, and a second flange 41 which is a flange provided at an end of a second rotating shaft 4 is connected to the rear side of the torque meter 1. The second rotating shaft 4 is rotated by a driving device 6 such as an engine or an electric motor, the first rotating shaft 3 is connected to a load device 5 such as a dynamometer, and the torque measuring device measures the torque acting between the driving device 6 and the load device 5. However, it is also possible to configure the second rotating shaft 4 to be connected to the load device 5, and the first rotating shaft 3 to be rotated by the driving device 6.

Here, in the measurement system, the torque meter 1 is supported by a first rotating shaft 3 and a second rotating shaft 4 connected to the torque meter 1 so that a portion of the axial direction is located within the hollow of the ring portion 21 without contacting the ring portion 21 of the stator 2.

The ring portion 21 of the stator 2 forms a one-turn coil that functions both as a power transmission coil for wireless power supply and as a wireless communication antenna, and the stator 2 can transmit power wirelessly to the torque meter 1 and communicate wirelessly with the torque meter 1.

FIG. 2 shows the configuration of the torque meter 1.
2a1 shows a front view of the torque meter 1, FIG. 2a2 shows a side view of the torque meter 1, and FIG. 2a3 shows a rear view of the torque meter 1.
As shown in Figures 2a1 and 2a3, a phase angle is defined as proceeding from 0 degrees to 360 degrees clockwise as viewed from the front, and Figure 2b shows a cross-sectional view taken along the cutting line A-A at a phase angle of 0 degrees shown in Figure 2a1. Here, where i is an integer from 0 to 7, a cross-section taken along a cutting line at a phase angle of 0 + (45 x i) degrees is the same as Figure 2b.

Also, Fig. 2c shows a cross-sectional view taken along line B-B at a phase angle of 22.5 degrees shown in Fig. 2a3, where the cross-section taken along the line at a phase angle of 22.5 + (45 x i) degrees is the same as Fig. 2c.
Fig. 2d shows a cross-sectional view taken along line CC at a phase angle of 11.25 degrees shown in Fig. 2a3, where the cross-section taken along the line at a phase angle of 11.25 + (45 x i) degrees is the same as Fig. 2d.
As shown in each figure, the torque meter 1 has a hollow cylindrical strain-flexing part 11, a disk-shaped first disk portion 12 with a central hole and provided in the form of a flange on the front side of the strain-flexing part 11, a disk-shaped second disk portion 13 with a central hole and provided in the form of a flange on the back side of the strain-flexing part 11, and an auxiliary flange 14 provided on the outer peripheral surface of the second disk portion 13.

The central portion of the strain-generating portion 11 in the axial direction is made thin so that it can be easily deformed, and as shown in Figure 2d, a strain gauge 15 is fixed to this thin portion at a phase angle of 11.25 + (45 x i) degrees.

The first disk portion 12 has eight bolt holes 121 spaced at equal phase angle intervals along the circumference, and each bolt hole 121 is provided at a position at a phase angle of 0+(45×i) degrees.
The second disk portion 13 has eight screw holes 131 arranged at equal phase angle intervals along the circumference, and each screw hole 131 is provided at a position of a phase angle of 22.5+(45×i) degrees.
The second disk portion 13 has eight through holes 132 spaced at equal phase angle intervals along the circumference, and each through hole 132 is provided at a phase angle of 0+(45×i) degrees.
A coil 16 that serves as both a power receiving coil for wireless power supply and a wireless communication antenna is wound around the outer circumferential end of the first disk portion 12 .
Here, as shown in FIG. 1a, the first disk portion 12 is disposed within the hollow of the ring portion 21 of the stator 2, and the torque meter 1 can wirelessly receive power from the stator 2 via the coil 16 wound around the outer peripheral end of the first disk portion 12, and can communicate with the stator 2 wirelessly.

The strain gauge 15 detects the strain of the strain-generating part 11 using the power supplied to the coil 16, and the strain detected by the strain gauge 15 is transmitted to the stator 2 by wireless communication via the coil 16.

As shown in the side view of FIG. 3a and the rear view of FIG. 3b, the torque meter 1 can be equipped with a ring-shaped gear 17 used for rotation detection, using the auxiliary flange 14 provided on the outer peripheral surface of the second disk portion 13. When rotation detection is performed using the gear 17, a magnetic sensor 22 that detects magnetic changes caused by the passage of the teeth of the gear 17 is provided on the stator 2, and the rotation angle and rotation speed of the torque meter 1 are calculated from the output of the magnetic sensor 22. However, instead of the gear 17, a ring-shaped disk with slits arranged in the circumferential direction may be provided on the torque meter 1 using the auxiliary flange 14, and instead of the magnetic sensor 22, an optical sensor that detects optical changes caused by the passage of the slits may be provided on the stator 2, and the rotation angle and rotation speed of the torque meter 1 may be calculated from the output of the optical sensor.

Next, a connection structure between the first rotating shaft 3, the second rotating shaft 4, and the torque meter 1 when configuring a measurement system will be described.
As shown diagrammatically in FIG. 4a, a first flange 31 at the end of the first rotating shaft 3 is connected to the front side of the torque meter 1, and a second flange 41 at the end of the second rotating shaft 4 is connected to the rear side of the torque meter 1. The torque meter 1 detects the torque transmitted between the second rotating shaft 4 and the first rotating shaft 3 as a strain of the strain-flexing part 11 using a strain gauge 15.

The first flange 31 is connected to the torque meter 1 by fastening the first disk portion 12 and the first flange 31 with bolts as shown in the side view of FIG. 4b. The second flange 41 is connected to the torque meter 1 by fastening the second disk portion 13 and the second flange 41 with bolts as shown in the side view of FIG. 4b.

The first rotating shaft 3 and the second rotating shaft 4 are connected to the torque meter 1 in the following procedure.
First, as shown in Figure 4c1, a bolt is passed through the through hole 132 of the second disk portion 13 and inserted into the bolt hole 121 of the first disk portion 12, and the bolt inserted into the bolt hole 121 is screwed into the connecting screw hole 311 provided in the first flange 31 of the first rotating shaft 3, thereby fastening the first disk portion 12 and the first flange 31.

Next, as shown in FIG. 4c2, the second disk portion 13 and the second flange 41 are fastened together by inserting a bolt into the connecting bolt hole provided in the second flange 41 of the second rotating shaft 4 and screwing it into the screw hole 131 of the second disk portion 13.

In this manner, in the torque meter 1 according to this embodiment, both the first flange 31 and the second flange 41 can be fastened to the torque meter 1 from the rear surface side.
Next, FIG. 5a1 shows a schematic perspective view of the periphery of the bolt hole 121 of the first disk portion 12 as viewed from the front side, and FIG. 5a2 shows a schematic cross section of the periphery of the bolt hole 121 of the first disk portion 12.

The front end surface of the first disk portion 12 forms the same plane with the axial direction as the normal line, except for the periphery of the bolt hole 121, but as shown in the figure, the periphery of the bolt hole 121 protrudes (is convex) slightly toward the front in an annular shape with the bolt hole 121 as the central hole from the plane outside the periphery of the bolt hole 121. For example, the diameter of the bolt hole 121 is φ19, the height of the part protruding from the plane around the bolt hole 121 is 0.1 mm, and the diameter is φ29.

On the other hand, the end face of the first flange 31 of the first rotating shaft 3 that faces the front end face of the first disk portion 12 is formed into a flat surface.
Therefore, when the first flange 31 is fastened to the first disk portion 12 with bolts, the area of the first disk portion 12 that comes into axial contact with the first flange 31 is only the area around the bolt hole 121 shown in gray in Figure 5b.

Next, FIG. 6a1 shows a schematic perspective view of the periphery of the screw hole 131 of the second disk portion 13 as viewed from the rear side, and FIG. 6a2 shows a schematic cross section of the screw hole 131 of the second disk portion 13.
The rear end face of the second disk portion 13 forms the same plane with the axial direction as a normal line, except for the periphery of the screw hole 131, but as shown in the figure, the periphery of the screw hole 131 protrudes (is convex) slightly toward the rear in a circular shape with the screw hole 131 as a central hole from the plane outside the periphery of the screw hole 131. For example, the shape of the convex portion is M18 for the screw hole 131, the height of the portion protruding from the plane around the screw hole 131 is 0.1 mm, and the diameter is φ29.

As shown in Figs. 6b1 and 6b2, the periphery of the through hole 132 of the second disk portion 13 does not protrude in the rear direction.
On the other hand, the end face of the second flange 41 of the second rotating shaft 4 that faces the rear end face of the second disk portion 13 is formed into a flat surface.
Therefore, when the second flange 41 is fastened to the second disk portion 13 with bolts, the area of the second disk portion 13 that comes into axial contact with the second flange 41 is only the area around the screw hole 131 shown in gray fill in Figure 6c.

With this torque meter 1, the area of the contact region where the first disk portion 12 and the first flange 31 come into axial contact, and the area of the contact region where the second disk portion 13 and the second flange 41 come into axial contact, can be reduced by concentrating the contact region only in the area around the bolt.

The inventors have confirmed through experiments that reducing the contact area in this way reduces the measurement hysteresis of the torque meter 1 and suppresses changes in measurement hysteresis due to differences in the thickness and rigidity of the first flange 31 and the second flange 41.

It is believed that such an effect is obtained for the following reasons.
When the entire front end surface of the first disk portion 12 is brought into contact with the first flange 31 as a contact surface and the first disk portion 12 and the first flange 31 are fastened together, if the first flange 31 is deformed by the applied torque and the contact area between the first disk portion 12 and the first flange 31 changes, the stress distribution in the first flange 31 changes so that the stress is concentrated on the contact surface as the contact area decreases. Since the deformation of the first flange 31 depends on the magnitude of the applied torque, the stress distribution in the first flange 31 also changes according to the magnitude of the applied torque. Furthermore, since the stress is generated as a force against the torque, the stress changes in the opposite directions when the torque increases and when it decreases.

The change in the stress distribution and the direction of the stress change in the first flange 31 due to the change in the contact area between the first disk portion 12 and the first flange 31 in response to the applied torque causes hysteresis in the measurement of the strain gauge 15.

On the other hand, in the torque meter 1 of this embodiment, the contact points between the first disk portion 12 and the first flange 31 are concentrated only around the bolt, and the contact area is also small. Therefore, the change in the contact area between the first disk portion 12 and the first flange 31 due to a change in the applied torque is small, and the difference in this change due to differences in the thickness and rigidity of the first flange 31 is also small.

As a result, the measurement hysteresis of the torque meter 1 can be kept small, and changes in the measurement hysteresis due to differences in the thickness and rigidity of the first flange 31 can be suppressed.

The same is true for the second disk portion 13 and the second flange 41, which allows the hysteresis to be kept small and also reduces changes in the hysteresis of the torque meter 1 caused by differences in the thickness and rigidity of the second flange 41.

The inventors also confirmed through experiments that the reduction in contact area as described above also suppresses changes in the sensitivity of the torque meter 1 caused by differences in the thickness and rigidity of the first flange 31 and the second flange 41.

It is believed that such an effect is obtained for the following reasons.
When the entire front end surface of the first disk portion 12 is brought into contact with the first flange 31 as a contact surface and the first disk portion 12 and the first flange 31 are fastened together, the stress distribution of the contact surface of the first disk portion 12 in the fastened state changes depending on the thickness and rigidity of the first flange 31, and the torque transmission path between the first disk portion 12 and the first flange 31 becomes different. Therefore, depending on the thickness and rigidity of the first flange 31, the stress distribution of the strain-generating portion 11 when torque is applied and the type of strain generated become different, and different strains are detected by the strain gauge 15. As a result, the sensitivity of the torque meter 1 becomes different depending on the thickness and rigidity of the first flange 31.

On the other hand, in the torque meter 1 of this embodiment, the contact points between the first disk portion 12 and the first flange 31 are concentrated only around the bolt, and the contact area is also small. Therefore, even if the thickness and rigidity of the first flange 31 differ, the change in stress distribution on the contact surface of the first disk portion 12 in the fastened state is small, and as a result, the change in sensitivity of the torque meter 1 due to differences in the thickness and rigidity of the first flange 31 can be kept small.

The same is true for the second disk portion 13 and the second flange 41, and the change in sensitivity of the torque meter 1 caused by differences in the thickness and rigidity of the second flange 41 can be suppressed to a small value.
The embodiment of the present invention has been described above.
In the above embodiment, the periphery of the bolt hole 121 on the front end face of the first disk portion 12 is protruded in the front direction, so that the area in which the first disk portion 12 and the first flange 31 of the first rotating shaft 3 contact in the axial direction is limited to the area around the bolt hole 121. However, the front end face of the first disk portion 12 may be formed flat without protruding the periphery of the bolt hole 121 on the front end face of the first disk portion 12, and instead, as shown in the schematic oblique view of the first rotating shaft 3 and the first flange 31 in Figure 7a1 and the schematic oblique view of the area around the connecting screw hole 311 of the first flange 31 in Figure 7a2, the area in which the first disk portion 12 and the first flange 31 of the first rotating shaft 3 contact in the axial direction may be limited to the area around the bolt.

In the above embodiment, the periphery of the screw hole 131 on the rear end face of the second disk portion 13 is protruded toward the rear, so that the area in which the second disk portion 13 and the second flange 41 of the second rotating shaft 4 contact in the axial direction is limited to the area around the screw hole 131. However, this is possible by forming the rear end face of the second disk portion 13 as a flat surface without protruding the periphery of the screw hole 131 on the rear end face of the second disk portion 13, and instead, by slightly protruding the periphery of the connecting bolt hole of the second flange 41 of the second rotating shaft 4 in the front direction, as shown in the schematic perspective view of the second rotating shaft 4 and the second flange 41 in FIG. 7b1 and the schematic perspective view of the periphery of the connecting bolt hole of the second flange 41 in FIG. 7b2, so that the area in which the second disk portion 13 and the second flange 41 of the second rotating shaft 4 contact in the axial direction is limited to the area around the bolt.

In another embodiment, the front end surface of the first disk portion 12 may be formed flat without protruding the periphery of the bolt hole 121, and instead, a circular member may be used as a washer for the bolt used to connect the first disk portion 12 to the first flange 31 of the first rotating shaft 3.

In this case, as shown in the schematic diagram of FIG. 8a1 and the cross-sectional diagram of FIG. 8a2, the bolt used to connect the first disk portion 12 and the first flange 31 is passed through the central hole of the annular member 7 between the front end face of the first disk portion 12 and the first flange 31, and screwed into the connecting screw hole 311 of the first flange 31.

As shown in Figure 8a2, the circular member 7 is painted black. Even when the circular member 7 is used in this manner, the area in which the first disk portion 12 and the first flange 31 make axial contact can be limited to the area around the bolt, thereby reducing the contact area between the first disk portion 12 and the first flange 31.

Similarly, the rear end surface of the second disk portion 13 may be formed flat without protruding the periphery of the screw hole 131, and instead the annular member 7 may be used as a washer for the bolt used to connect the second disk portion 13 to the second flange 41 of the second rotating shaft 4.

In this case, as shown in Figures 8b1 and 8b2, the bolt used to connect the second disk portion 13 and the second flange 41 is passed through the central hole of the annular member 7 between the rear end face of the second disk portion 13 and the second flange 41 and screwed into the screw hole 131 of the second disk portion 13.

As shown in Figure 8b2, where the circular member 7 is painted black, even when the circular member 7 is used in this manner, the area in which the second disk portion 13 and the second flange 41 make axial contact can be limited to the area around the bolt, thereby reducing the contact area between the second disk portion 13 and the second flange 41.

In the above embodiment, the first disk portion 12 and the first flange 31 are configured to contact only around the bolt hole 121, but as long as the area of axial contact is limited to the area around the bolt hole 121, there may be areas other than the area around the bolt hole 121 where the first disk portion 12 and the first flange 31 contact.

The area where the first disk portion 12 and the first flange 31 contact each other other than around the bolt hole 121 may be an area where the first disk portion 12 and the first flange 31 contact each other in the radial direction in a structure provided for centering the first disk portion 12 and the first flange 31.

Similarly, the second disk portion 13 and the second flange 41 are configured to contact only around the screw hole 131, but as long as the area of axial contact is limited to the area around the screw hole 131, there may be areas other than the area around the screw hole 131 where the second disk portion 13 and the second flange 41 contact.

The area where the second disk portion 13 and the second flange 41 contact each other other than around the screw hole 131 may be an area where the second disk portion 13 and the second flange 41 contact each other in the radial direction in a structure provided for centering the second disk portion 13 and the second flange 41.

For example, as shown in the rear view of FIG. 9a1 and the perspective view from the rear direction of FIG. 9a2, a ring-shaped protrusion 81 protruding in the rear direction may be provided around the central hole of the second disk portion 13, as shown in FIG. 9b1, a circular protrusion 82 that fits into the central hole of the first disk portion 12 may be provided on the first flange 31, as shown in FIG. 9b2, a circular recess 83 that fits into the protrusion 81 of the second disk portion 13 may be provided on the second flange 41, as shown in FIG. 9c, the protrusion 82 of the first flange 31 may be inserted into the central hole of the first disk portion 12 to loosely fit the first flange 31 and the first disk portion 12, and the protrusion 81 of the second disk portion 13 may be inserted into the recess 83 of the second flange 41 to loosely fit the first flange 31 and the first disk portion 12 to center the second flange 41 and the second disk portion 13.

However, the shape of the convex portion 82 of the first flange 31 is set so that the first flange 31 and the first disk portion 12 do not come into contact in the axial direction when they are fastened, and the shapes of the protruding portion 81 of the second disk portion 13 and the concave portion 83 of the second flange 41 are set so that the second flange 41 and the second disk portion 13 do not come into contact in the axial direction when they are fastened.

1...torque meter, 2...stator, 3...first rotating shaft, 4...second rotating shaft, 5...load device, 6...drive device, 7...annular member, 9...torque meter, 11...strain generating portion, 12...first disk portion, 13...second disk portion, 14...auxiliary flange, 15...strain gauge, 16...coil, 17...gear, 21...ring portion, 22...magnetic sensor, 31...first flange, 41...second flange, 81...projecting portion, 82...convex portion, 83...concave portion, 91...hollow body portion, 92...drive side flange portion, 93...load side flange portion, 121...bolt hole, 131...screw hole, 132...through hole, 311...connecting screw hole.

Claims (4)

A measurement system including a first rotating shaft, a second rotating shaft, and a torque meter that detects torque transmitted between the first rotating shaft and the second rotating shaft,
The torque meter includes a first disk portion, a second disk portion, a strain generating portion connecting the first disk portion and the second disk portion, and a strain detection means for detecting a strain generated in the strain generating portion,
A first flange is provided at an end of the first rotating shaft, the first flange being a flange connected to the first disk portion by a bolt,
The end of the second rotating shaft is provided with a second flange which is a flange connected to the second disk portion by a bolt.
A measurement system characterized in that at least a portion of the area around a bolt hole or screw hole through which a bolt connecting the first disk portion is inserted on the surface of the first flange facing the first disk portion has a shape that protrudes toward the first disk portion so that the only point where the first flange and the first disk portion abut in the axial direction is the said portion. 2. The measurement system of claim 1,
A measurement system characterized in that at least a portion of the area around a bolt hole or screw hole through which a bolt connecting the second disk portion is inserted on the surface of the second flange facing the second disk portion has a shape that protrudes toward the second disk portion so that the only point where the second flange and the second disk portion abut in the axial direction is the said portion. A measurement system including a first rotating shaft, a second rotating shaft, and a torque meter that detects torque transmitted between the first rotating shaft and the second rotating shaft,
The torque meter includes a first disk portion, a second disk portion, a strain generating portion connecting the first disk portion and the second disk portion, and a strain detection means for detecting a strain generated in the strain generating portion,
A first flange is provided at an end of the first rotating shaft, the first flange being a flange connected to the first disk portion by a bolt,
The end of the second rotating shaft is provided with a second flange which is connected to the second disk portion by a bolt.
The measurement system includes a first annular member that is an annular member having a hole;
the first annular member is disposed between the first flange and the first disk portion such that the first flange and the first disk portion do not directly contact each other in the axial direction,
a bolt connecting the first flange and the first disk portion being passed through a hole in the first annular member between the first flange and the first disk portion, thereby connecting the first flange and the first disk portion. 4. The measurement system according to claim 3,
a second annular member that is an annular member having a hole;
the second annular member is disposed between the second flange and the second disk portion such that the second flange and the second disk portion do not directly contact each other in the axial direction,
A measurement system characterized in that the bolt connecting the second flange and the second disk portion is passed through a hole in the second annular member between the second flange and the second disk portion, connecting the second flange and the second disk portion.