JP5712759B2 - Physical quantity measuring device for gear transmission - Google Patents

Description

  The present invention relates to a physical quantity related to a gear constituting a gear transmission device incorporated in an automobile transmission or the like, specifically, a displacement of the gear that changes according to a torque transmitted by the gear transmission device, or The present invention relates to a measuring apparatus for measuring the value of this torque correlated with this displacement.

  Regardless of whether it is a stepped type or a stepless type, a gear transmission mechanism is incorporated in an automobile transmission. Belt-type and toroidal type continuously variable transmissions for automobiles have been put into practical use, but any type of transmission prevents excessive slippage in the power transmission section (traction section). Therefore, a pressing device for securing the surface pressure of the power transmission unit is provided. In order to improve the transmission efficiency of the continuously variable transmission, it is preferable to adjust the pressing force generated by the pressing device according to the magnitude of the torque transmitted by the continuously variable transmission. That is, when the torque is low, the pressing force is kept low, and the resistance acting on the power transmission unit (friction resistance, rolling resistance, etc. not contributing to power transmission) is kept low, whereas the torque is high. In this case, it is preferable to increase the pressing force to prevent excessive slippage in the power transmission unit.

  For this purpose, a hydraulic device is used as the pressing device, the torque input to the continuously variable transmission is measured, and the pressing force generated by the pressing device is adjusted according to the measured value of the torque. However, such a mechanism has already been partially implemented. The torque measurement in this case is performed based on a signal from a control computer for controlling the engine. However, in such a configuration, in the state where the output of the engine is transmitted to the drive wheels, the surface pressure of the power transmission portion of the continuously variable transmission can be made appropriate, but the torque from the drive wheel side to the continuously variable transmission can be increased. If is inputted, there is a possibility that this surface pressure cannot be made appropriate. That is, when a large engine brake is applied, such as when driving on a downhill with a large reduction gear ratio of the continuously variable transmission, a large torque from the output side is accelerated to the continuously variable transmission. It is input in the direction opposite to time. In this state, the output torque of the engine (the input torque of the continuously variable transmission from the front stage side) is zero or very small. In such a case, if the adjustment of the pressing force is performed based only on the input torque from the engine side, the surface pressure of the power transmission unit of the continuously variable transmission is insufficient, and this power transmission unit is excessive. There is a possibility that the durability of the continuously variable transmission may be impaired, for example, slippage may occur and wear of each surface constituting the power transmission unit may increase.

  In order to prevent such a decrease in the durability of the continuously variable transmission, the torque passing through the continuously variable transmission (transmitted by the continuously variable transmission) is measured regardless of the direction of passage. It is effective to adjust the pressing force generated by the pressing device based on the measured value. As a device that enables such torque measurement, a torque measurement device as described in Patent Document 1 is widely known. FIG. 15 shows the principle of such a torque measuring device. In this torque measuring device, a pair of encoders 2a and 2b are fixed to the outer peripheral surface of the rotary shaft 1 in a state of being separated in the axial direction, and sensors 3a are respectively attached to the detected surfaces (outer peripheral surfaces) of these encoders 2a and 2b. 3b are opposed to each other. The relationship between the output signals of these sensors 3a and 3b has a predetermined phase difference as an initial value when the rotary shaft 1 does not transmit torque and thus the rotary shaft 1 is not elastically deformed. On the other hand, when the rotating shaft 1 transmits torque and the rotating shaft 1 is elastically deformed in the torsional direction, the phase difference between the output signals of the sensors 3a and 3b is deviated from the initial value. Since the magnitude of the deviation from the initial value of the phase difference is substantially proportional to the magnitude of the torque transmitted by the rotary shaft 1, it is possible to obtain this torque based on the phase difference. it can.

  On the other hand, Patent Document 2 describes a gear transmission device incorporating a helical gear, and a device for obtaining the direction and magnitude of torque transmitted by the gear transmission device. In the conventional structure described in Patent Document 2, the rotating shaft to which the helical gear is fixed corresponds to the magnitude of this torque in the direction corresponding to the direction of the torque transmitted by the gear transmission device with respect to the axial direction. Use the displacement by the amount. For this reason, in this structure, the rotary shaft is elastically supported by a compression coil spring so as to be axially displaceable, and the axial displacement of the rotary shaft can be measured by a displacement measuring instrument.

  In any of the structures described above, there is a possibility that a structure can be realized that is incorporated in a continuously variable transmission for an automobile and that can measure the torque passing through the continuously variable transmission regardless of the direction of passage. However, none of the structures is premised on being incorporated into a continuously variable transmission, and dedicated components are incorporated in addition to the sensor in order to constitute a torque measuring device. For this reason, parts production, parts management, and assembly work are all cumbersome, which not only increases costs, but also increases installation space, and the casing in which the components of the continuously variable transmission are stored is limited. It is difficult to install in a space. Therefore, it is difficult to apply these structures to applications where installation space is limited, such as continuously variable transmissions for automobiles.

  On the other hand, in the case of a continuously variable transmission, a gear transmission mechanism is not incorporated in the transmission mechanism itself (so-called variator section), but torque is transmitted from the output section of this transmission mechanism to the output shaft of the continuously variable transmission as a whole. A gear transmission mechanism is incorporated in the part to be performed. The gears constituting the gear transmission mechanism are slightly displaced in an amount corresponding to the magnitude of the torque in a direction corresponding to the direction of the torque according to the direction and magnitude of the torque to be transmitted. Therefore, if the displacement direction and displacement amount of the gear are measured by a sensor incorporated in the gear transmission mechanism, the gear transmits without using a dedicated component for torque measurement like an encoder. Torque can be obtained.

  The encoder is fixed to a part of the rotating shaft concentrically with the rotating shaft, and the detection portions of a plurality of sensors are opposed to the detection surface of the encoder, and exist between the output signals of these sensors. Patent Document 3 discloses an apparatus for measuring a displacement amount in each direction of the rotating shaft, and further a load or force (moment) in each direction applied between the rotating shaft and a stationary member based on a phase difference to be performed. Have been described. The measuring device described in Patent Document 3 measures a physical quantity based on a phase difference existing between output signals of a plurality of sensors. Even in this structure, a physical quantity such as a displacement, a load, and a force is measured. In order to measure the torque transmitted by the gear transmission incorporated in the continuously variable transmission, a conventional encoder shown in FIG. 15 is provided. Cause similar problems. In the case of this structure, for example, the radial load, the thrust load, and the moment applied to the hub constituting the automobile hub unit can be obtained, but the torque applied to the hub cannot be obtained.

JP 2002-350251 A Japanese Patent Laid-Open No. 9-250958 JP 2008-64731 A

  In view of the circumstances as described above, the present invention can measure the displacement direction and the displacement amount of the gears constituting the gear transmission device without installing an element for measuring a physical quantity other than the sensor in the gear transmission device part. Thus, a measuring device having a structure capable of measuring the direction and magnitude of the torque transmitted by the gear transmission device is to be realized.

Each of the physical quantity measuring devices for a gear transmission device according to the present invention includes a pair of rotating shafts, a gear transmission device, at least a pair of sensors, and a calculator.

  The gear transmission device includes at least one pair of gears. Each of these gears is fixed to a part of each of the pair of rotating shafts, and the teeth formed on the respective outer diameter side end portions are engaged with each other, whereby the torque between these rotating shafts can be reduced. Communication is possible.

  In addition, each sensor of the pair of sensors is configured so that each detection portion is opposed to a tooth provided on the outer diameter side end portion of at least one gear of the pair of gears. The output signal is changed with rotation. In the interpretation of the present invention, the term “teeth” means not only individual teeth but also a set of a large number of teeth that are continuous in the circumferential direction.

  Further, the computing unit calculates a physical quantity related to the gears with the detection units of these sensors facing each other based on the phase difference existing between the output signals of the sensors.

When implementing the physical quantity measuring device for a gear transmission device having the above-described premise configuration , the gear is a helical gear as in the first aspect of the invention .

Then, the detection part of one of the pair of sensors is detected by the other sensor in the radial direction with respect to the teeth formed on the outer diameter side end of one of the pair of gears. The portions are made to face each other in the axial direction with respect to the teeth formed on the outer diameter side end portion of the one gear. That is, the detection portions of both sensors are opposed to the teeth formed on the outer diameter side end portion of the same gear in both the radial direction and the axial direction.

  Further, based on the change of the phase difference existing between the output signals of these sensors, the calculator calculates at least one of the axial displacement amount of the one gear and the torque transmitted by the gear. Have a function to calculate.

On the other hand, in the case where the physical quantity measuring device for a gear transmission device having the above-described premise configuration is implemented, it is out of the technical scope of the present invention. , With respect to the teeth formed on the outer diameter side end portion of one gear of the pair of gears, the detection portion of the other sensor, It is also possible to adopt a configuration in which the teeth formed on the outer diameter side end of the other gear are respectively opposed in the radial direction.

Further, when such a configuration is adopted, the arithmetic unit is configured to detect a phase difference existing between the output signals of the sensors, which is generated along with the relative displacement in the axial direction of the pair of gears. Based on the change, it is possible to adopt a configuration having a function of calculating at least one of the relative displacement amount of the gears in the axial direction and the torque transmitted between the gears.

In the case of adopting the above-described configuration, additionally, the one pair of sensors is arranged at a position closer to the meshing portion than a position of 90 ° in the circumferential direction from the meshing portion of the pair of gears, A configuration in which these sensors are held in a single holder can be employed .

Further, in the case where the physical quantity measuring device for a gear transmission device having the above-described premise configuration is implemented, it is out of the technical scope of the present invention, but in addition, each detection unit of the pair of sensors is provided. In addition, it is possible to adopt a configuration in which the teeth formed on the outer diameter side end portions of the pair of gears are opposed to each other in the radial direction.

Further, the arithmetic unit is configured to detect the relative relationship between the gears based on the change in the phase difference existing between the output signals of the sensors, which occurs with the relative position change between the central axes of the pair of gears. It is also possible to adopt a configuration that calculates at least one of the displacement amount and the torque transmitted between these gears.

When the above-described configuration is adopted, more specifically, each detection portion of the pair of sensors is positioned at a position opposite to the 180 ° (separate gears) with the meshing portion of the pair of gears interposed therebetween. It is possible to adopt a configuration that opposes the portion on the opposite side in the radial direction. When such a configuration is adopted , the phase difference between the output signals of the gears is caused by the relative displacement of the rotation centers of the gears in the tangential direction of the meshing portion. It is possible to adopt a configuration that changes

Alternatively, the detection part of each sensor constituting the sensor is moved from a position opposite to the 180 ° across the meshing part of the gear from the pressure angle of these gears (one point on the reference circle of the tooth surface of each gear). In this case, it is also possible to adopt a configuration in which the gears are arranged at positions that are respectively moved in the circumferential direction by an angle formed by the radial line of the gear and the tangent of the tooth surface. When such a configuration is adopted , the phase difference between the output signals of the gears is caused by the relative displacement of the rotation centers of the gears in the tangential direction of the meshing portion by the sensors. It is also possible to adopt a configuration that changes.

Or the structure which makes the detection part of the said one pair of sensor oppose the outer peripheral surface of one gear among said one pair of gears is also employable . In addition, it is possible to employ a configuration in which the positions where both the detection portions of these sensors are opposed to the one gear are portions shifted by 90 ° in the circumferential direction from the meshing portions of the gears. And when such a structure is employ | adopted, the said one pair of sensors will detect the phase difference between mutual output signals, when the said one gearwheel is displaced to the direction away from the other gearwheel. It is possible to adopt a configuration that changes. In this configuration, a pair of sensors can be arranged on each of both gears constituting a pair of gears, and the displacement amounts of both of these gears can be obtained by two pairs of sensors.

When the physical quantity measuring device for a gear transmission device having the above-described premise configuration is implemented, the pair of gears are helical gears as in the invention described in claim 2 . And the detection part of one sensor of the pair of sensors is opposed to the teeth formed on the outer diameter side end of one gear of the pair of gears in the radial direction, and the sensor of the other sensor The detecting portion is adjacent to the one gear and is opposed to teeth formed on the outer diameter side end portion of the spur gear fixed to the same rotation shaft as the one gear in the radial direction.

  Further, based on a change in phase difference existing between the output signals of the pair of sensors, the axial displacement amount of one of the gears and the torque transmitted by the gears are transmitted to the computing unit. And a function of calculating at least one of the above. Even in this configuration, another pair of sensors are fixed to the other helical gear fixed to the other rotating shaft and the same rotating shaft as the other gear adjacent to the other gear. It can also be applied to a combination with a spur gear, and the displacement amounts of both sets of gears fixed to different rotating shafts can be obtained by two pairs of sensors.

Further, when the physical quantity measuring device for a gear transmission device having the above-described premise configuration is implemented, among the pair of gears, the sensor of the pair of sensors as in the invention described in claim 3. A sensor detection groove can be provided in a part of the tooth tip surface of the tooth provided on the outer diameter side end of the gear facing the detection unit.

Further, in carrying out the physical quantity measuring device for a gear transmission device having the above-described premise configuration, the detection unit of the pair of sensors out of the pair of gears is out of the technical scope of the present invention. An elastic force that presses the rotating shaft in the axial direction with a predetermined force can be applied to the rotating shaft with the gears facing each other fitted and fixed.

  According to the physical quantity measuring device for a gear transmission device of the present invention configured as described above, the displacement direction and the displacement amount of the gears constituting the gear transmission device can be measured. Therefore, it is possible to measure the direction and magnitude of the torque transmitted by the gear transmission device without installing a dedicated component for torque measurement other than the sensor in the gear transmission device portion. As a result, parts production, parts management, and assembly work are all facilitated, and the cost increase associated with incorporating the physical quantity measuring device into the gear transmission device can be kept low. In addition, it is easy to install in a limited space in the casing containing the components of the continuously variable transmission, for example, with a small installation space.

FIG. 1 illustrates a first example of an embodiment of the present invention in which a pair of helical gears and a pair of sensors meshed with each other are viewed from the axial direction of these helical gears. FIG. FIG. 2 is a perspective view showing a combination state of one helical gear of the pair of helical gears and the pair of sensors. FIG. 3 is a schematic diagram for explaining a force applied to a pair of helical gears meshed with each other. FIG. 4 is a flowchart showing a procedure for obtaining the torque transmitted by the pair of helical gears based on the phase difference between the output signals of the pair of sensors. FIG. 5 is a diagram showing a state in which the phase of the output signal of the pair of sensors changes with the axial displacement of the pair of helical gears. FIG. 6 illustrates a first example of a reference example related to the present invention, in which a pair of helical gears and a pair of sensors engaged with each other are viewed from the radial direction of the helical gears. It is a schematic side view shown by. FIG. 7 is a view showing a pair of helical gears and a pair of sensors meshed with each other as viewed from the axial direction of the helical gears in order to explain a second example of the reference example related to the present invention . It is a schematic front view shown by. FIG. 8 illustrates a third example of a reference example related to the present invention, in which a pair of helical gears and a pair of sensors engaged with each other are viewed from the axial direction of the helical gears. It is a schematic front view shown by. FIG. 9 illustrates a fourth example of a reference example related to the present invention, in which a pair of helical gears and a pair of sensors meshed with each other are viewed from the axial direction of these helical gears. It is a schematic front view shown by. FIG. 10 illustrates a fifth example of a reference example related to the present invention, in which a pair of helical gears and a pair of sensors meshed with each other are viewed from the axial direction of the helical gears. It is a schematic front view shown by. FIG. 11 shows a pair of helical gears meshed with each other and a pair of spur gears adjacent to the helical gears and two pairs for explaining a second example of the embodiment of the present invention. It is a schematic side view which shows this sensor in the state seen from the radial direction of these gears. 12 (a) and 12 (b) both illustrate one third spur gear and one of the pair of sensors in order to explain the third example of the embodiment of the present invention. It is the schematic side view and the schematic side perspective view which are shown in the state seen from the direction. FIGS. 13A and 13B are views similar to FIG. 12A for explaining a modification of the third example of the embodiment of the present invention. FIG. 14 is a schematic diagram showing one of the spur gear and the pair of sensors as viewed from the radial direction of the spur gear in order to explain a sixth example of the reference example related to the present invention . It is a side view. FIG. 15 is a schematic perspective view showing an example of a conventionally known torque measuring device.

[First example of embodiment]
A first example of an embodiment of the present invention corresponding to claim 1 will be described with reference to FIGS. In the case of the structure of this example, a pair of gears 4a and 4b are supported and fixed so as to rotate together with the rotation shafts 1a and 1b, respectively, in the middle part of the pair of rotation shafts 1a and 1b arranged in parallel to each other. Furthermore, these gears 4a and 4b are meshed with each other. The rotary shafts 1a and 1b are rotatably supported in a casing containing, for example, the components of the continuously variable transmission, with the radial and axial rattling suppressed. For this purpose, the rotary shafts 1a and 1b are supported on the end wall or intermediate support wall of the casing by rolling bearings to which preload is applied, such as angular ball bearings or tapered roller bearings. Each of the gears 4a and 4b is a helical gear made of magnetic metal such as tool steel, and teeth 5a and 5b inclined with respect to the axial direction are formed at the respective outer diameter side ends. Yes. The teeth 5a and 5b are meshed with each other without a gap (with zero backlash). With this configuration, a gear transmission device 6 is configured that can transmit torque between the rotating shafts 1a and 1b without causing a time lag based on backlash.

  One of the gears 4a and 4b (for example, a small diameter side where a reference circular diameter d described later is small and a force applied to meshing is large) is connected to the outer diameter side end of the gear 4a. The detectors are close to each other. Each of these sensors 7a and 7b is of a magnetic detection type in which a magnetic detection element such as a Hall element or a magnetoresistive element is combined with a permanent magnet, and according to changes in the magnetic characteristics of the portion facing the detection unit. Change the output signal. In the case of this example, an IC having a waveform shaping circuit is incorporated in the sensors 7a and 7b. Therefore, when the teeth 5a formed on the outer diameter side end portion of the one gear 4a pass through the vicinity of the respective detection portions (immediately before facing each other through a minute gap), these sensors 7a and 7b Based on the unevenness of the teeth 5a, a rectangular wave (pulse signal) as shown in FIG.

  Of the sensors 7a and 7b each having such characteristics, the detection part of one sensor 7a is opposed to the outer peripheral surface of the one gear 4a (the tip edge of the tooth 5a) in the radial direction. . On the other hand, the other sensor 7b is opposed in the axial direction to one axial end surface (the axial end surface of the tooth 5a) of the outer diameter side end portion of the one gear 4a. Note that the positions of the detection portions of the sensors 7a and 7b in the circumferential direction of the one gear 4a are substantially the same, and the sensors 7a and 7b are arranged close to each other. This is because the sensors 7a and 7b are embedded and supported in a single synthetic resin holder (not shown) to form an integrated sensor unit, and the positioning accuracy and assembly workability of these sensors 7a and 7b are improved. It is for making it good. In addition, although this shape differs about this synthetic resin holder, the synthetic resin holder 9 shown in FIG. 7 can be referred.

  The output signals of the sensors 7a and 7b are input to a calculator (not shown). Then, based on the information regarding the phase difference existing between the output signals of these sensors 7a and 7b, this calculator calculates the shaft of the portion where the sensors 7a and 7b are installed in the one gear 4a. A displacement amount with respect to the direction is calculated. Further, based on the amount of displacement, the torque transmitted by the gear transmission device 6 is calculated. Hereinafter, the procedure for obtaining the displacement amount and the torque T will be described with reference to FIGS.

  A force in a direction as indicated by an arrow in FIG. 3 is applied to the meshing portion of the pair of gears 4a and 4b, each of which is a helical gear. That is, as is widely known in the field of gear transmission, based on the meshing between the teeth 5a and 5b of the gears 4a and 4b, the tangential direction is the tangential direction of the meshing portion between these teeth 5a and 5b. A force Ft (Ft1, Ft2) is applied in a direction corresponding to the transmission direction of the torque T based on the pressing of the circumferential side surfaces of the teeth 5a, 5b. Further, a radial force Fr (Fr1, Fr2) is applied in the direction of separating the rotation centers of the gears 4a, 4b based on the inclination of the circumferential side surfaces of the teeth 5a, 5b. Further, an axial force Fx (Fx1, Fx2) in the direction in which the gears 4a, 4b are relatively displaced in the axial direction is inclined (torsion angle) of the teeth 5a, 5b with respect to the direction of the central axis of the gears 4a, 4b. On the basis of the transmission direction of the torque T.

The magnitudes of the forces Ft, Fr, and Fx are proportional to the torque T transmitted between the gears 4a and 4b, as represented by the following equation.
Ft∝2000T / d --- (1)
Fr∝Ft · (tan α / cos β) (2)
Fx∝Ft · tanβ --- (3)

  In these equations, T represents torque [N · m], d represents a reference circle diameter [mm], α represents a pressure angle [deg], and β represents a twist angle [deg]. The twist angle β is generally about 20 °, but in this example, it is set in the range of, for example, about 15 ° to 30 °.

  The gears 4a and 4b are pushed in each direction based on the forces Ft, Fr and Fx input from the meshing portion.

In the case of this example (not related to the case of the fourth to fifth examples of the embodiments described later), in the case of a spur gear, the twist angle β = 0, Since cos β = 1 and tan β = 0,
Fr∝Ft · tan α --- (4)
Fx = 0 --- (5)
It becomes.

  On the other hand, the gears 4a and 4b are fixed to the rotary shafts 1a and 1b, respectively, and the rotary shafts 1a and 1b can be freely rotated by a rolling bearing provided with a preload in the casing as described above. It is supported. When the torque transmission is transmitted by the gear transmission device 6, the rolling bearings, and further, the end wall or the intermediate support wall of the casing where the rolling bearings are installed, Elastically deforms based on Fr and Fx. Based on this elastic deformation, the rotating shafts 1a and 1b and the gears 4a and 4b supported and fixed to the rotating shafts 1a and 1b are displaced. The amount of displacement generated in this manner increases as the forces Ft, Fr, Fx increase in accordance with the torque T, and decreases as the support rigidity of the gears 4a, 4b increases (the support rigidity decreases). growing). In the case of this example, based on the phase difference of the output signals of the sensors 7a and 7b, the detection surfaces of the teeth 5a of the gear 4a on the small diameter side are closely opposed to each other, A displacement amount in the axial direction based on the axial force Fx is measured. Further, based on this displacement amount, a torque T transmitted by the gear transmission device 6 is calculated. This procedure will be described with reference to FIGS.

  In S (step) 1 shown in the flowchart of FIG. 4, when the gear transmission device 6 is transmitting torque T, in S <b> 2, the meshing portions of the teeth 5 a and 5 b of the gears 4 a and 4 b are engaged with each other. The forces Ft, Fr, and Fx are applied. In the case of this example, based on the axial force Fx, the small-diameter gear 4a is slightly displaced in the axial direction (for example, about several tens of μm) in S3. Based on this minute displacement, the phase difference between the output signals of the sensors 7a and 7b changes. That is, among these sensors 7a and 7b, the phase of the output signal of the sensor 7b in which the detector is opposed to the axial end surface of the tooth 5a does not change based on the displacement. On the other hand, the phase of the output signal of the sensor 7a having the detection portion opposed to the outer peripheral surface (tip edge) of the tooth 5a changes based on the displacement due to the presence of the twist angle of the tooth 5a.

  For example, when the gear transmission device 6 does not transmit the torque T (initial state), the phase difference (initial phase difference) δ between the output signals of the sensors 7a and 7b is as shown in FIGS. As shown by the upper broken line and the lower solid line, it is assumed that 1/2 of one cycle L (δ = L / 2). In this case, the initial phase difference δ is set so that a phase difference in a predetermined direction always exists regardless of the transmission direction of the torque T (the phase difference does not become zero in the process of reversing the acting direction of the torque T). It is important to make it easy to determine the direction and magnitude of the torque T based on this phase difference.

  When the gear 4a is displaced in the axial direction from the neutral state as described above, the detection surface of the sensor 7b (the portion where the detection portion of the sensor 7b faces the axial end surface of the tooth 5b) is Since the gear 4a does not move in the circumferential direction like S4 in FIG. 4, the phase of the output signal of the sensor 7b does not change. On the other hand, the surface to be detected of the sensor 7a on the outer peripheral surface side (the portion where the detection portion of the sensor 7a faces the tip surface of the tooth 5b) is based on the presence of the twist angle β. 4 moves in the circumferential direction as indicated by S5, so that the phase of the output signal of the sensor 7a changes. For example, when the gear 4a rotates in the direction of arrow A in FIG. 2, if the gear 4a is displaced in the direction of arrow B in the figure, the phase of the output signal of the sensor 7a on the outer peripheral surface side advances, The phase difference with the sensor 7b on the axial end face side becomes as short as δ1 (0 <δ1 <L / 2) in FIG. On the other hand, when the gear 4a is displaced in the direction of arrow C in the figure, the phase of the output signal of the sensor 7a on the outer peripheral surface side is delayed, and the phase difference between the sensor 7a and the sensor 7b on the axial end surface side is delayed. However, it becomes longer to about δ2 (L> δ2> L / 2) in FIG.

  In short, the phase difference existing between the output signals of the sensors 7a and 7b changes as in S6 of FIG. Thus, the direction in which the phase difference δ (δ1, δ2) changes with respect to the initial phase difference {δ (L / 2)} is determined according to the transmission direction of the torque T, and the magnitude of the change is large. The length is determined according to the magnitude of the torque T. That is, when the phase difference δ1 shown in FIG. 5A exists, the axial force corresponding to the phase difference of “δ−δ1” in the direction of arrow B in FIG. Fx is added. On the other hand, when the phase difference of δ2 shown in FIG. 5B exists, the gear 4a matches the phase difference of the magnitude of “δ2-δ” in the direction of arrow C in FIG. An axial force Fx is applied.

  The absolute value of the magnitude of the phase difference δ (δ1, δ2) varies according to the rotational speed of the gear 4a. Therefore, from this absolute value, the torque T can be obtained only when the rotational speed is a known constant value, whereas the rotational speed of the gear 4a in the continuously variable transmission varies greatly. Therefore, in S7, in order to eliminate the influence of the rotational speed, the phase difference δ (δ1, δ2) is divided by the one cycle L, and the ratio of the phase difference to the one cycle L, that is, the phase difference ratio. δ (δ1, δ2) / L is obtained. In S8, the phase difference ratio δ (δ1, δ2) / L is multiplied by a predetermined constant (displacement conversion constant) (a product is obtained), and in S9, the displacement amount of the gear 4a in the axial direction is determined. Ask. The displacement conversion constant can be easily obtained mathematically based on the number of teeth 5a, the twist angle β, and the like.

  When the displacement amount in the axial direction of the gear 4a is obtained in this way, in S10, the displacement amount is multiplied by a constant (load conversion constant) indicating the relationship between the displacement amount and the axial force Fx. . As shown in S11, this load constant is obtained in advance by experiment or calculation as shown in S12 while taking into account the support rigidity of the gear 4a, and based on the displacement, the axial force Fx. Incorporated in the software for seeking. Then, the axial force Fx is calculated by calculation using this software as shown in S13. As described above, the axial force Fx and the torque T have a relationship represented by the equations (1) and (3), and therefore exist at the meshing portion as shown in S14. While correcting the influence of friction (friction loss) and the like, the torque T is obtained from the axial force Fx in S15 of FIG. 4 by software incorporating the equations (1) and (3).

  As described above, according to the physical quantity measuring device for a gear transmission device of the present example, a single sensor unit in which a pair of sensors 7a and 7b are embedded and supported in a single holder in a casing of a continuously variable transmission. The torque T transmitted by the gear transmission device 6 provided in the continuously variable transmission can be obtained only by installing a harness for taking out the output signals of the sensors 7a and 7b. That is, in addition to the sensor unit and the harness, the direction and magnitude of the torque transmitted by the gear transmission device 6 can be measured without installing a dedicated component for torque measurement in the gear transmission device 6 portion. It becomes. As a result, parts production, parts management, and assembly work are all facilitated, and the cost increase associated with incorporating the physical quantity measuring device into the gear transmission 6 constituting the continuously variable transmission can be kept low. And it becomes easy to install in the limited space in the said casing, restraining installation space small.

  When a plurality of sets of gear transmission devices are provided in the continuously variable transmission, the sensor unit is installed in the gear transmission device at the subsequent stage (output side) to increase the torque measurement accuracy. Is advantageous. This is because, in the case of a general continuously variable transmission used as an automatic transmission for automobiles, the torque to be transmitted increases in the subsequent stage, and the amount of displacement of the gear also increases.

  Further, when obtaining the torque T based on the phase difference ratio δ (δ1, δ2) / L existing between the output signals of the sensors 7a and 7b, it is necessary to obtain the axial displacement amount of the gear 4a. There is no. For example, by installing software that incorporates an expression representing the relationship between the phase difference ratio δ (δ1, δ2) / L and the torque T in the computing unit, the phase difference ratio δ (δ1, δ2) The torque T can be obtained directly from / L. It should be noted that such an expression representing the relationship between the phase difference ratio δ (δ1, δ2) / L and the torque T is obtained by inputting the known torque to the gear transmission device 6 and outputting the output signals of the sensors 7a, 7b. It can be obtained by measuring the phase difference ratio δ (δ1, δ2) / L existing between them.

  Further, the arithmetic unit may be provided with a function of correcting an expression for obtaining the torque T from the phase difference ratio δ (δ1, δ2) / L according to a known torque. That is, if the friction coefficient of the meshing portion between the gears 4a and 4b changes, the formula for obtaining the torque T from the phase difference ratio δ (δ1, δ2) / L changes, and this friction coefficient is determined by the continuously variable transmission. As the tooth 5a and 5b become used, the change of the tooth 5a and 5b varies depending on the temperature and the degree of deterioration of the mission oil. On the other hand, the torque input to the continuously variable transmission can be known from information of an engine control computer or the like, and the input torque and the continuously variable transmission are also related to the torque passing through the gear transmission device 6 portion. Is obtained with sufficient accuracy on the basis of the transmission gear ratio of the transmission mechanism existing between the input portion and the gear transmission device 6 portion.

  Therefore, the phase difference ratio δ (δ1) existing between the torque obtained based on the input torque and the output signals of the sensors 7a and 7b in a state where the torque transmission device 6 transmits the torque. , Δ2) / L and correcting the gain and zero point in the above equation, the torque T can be accurately calculated from the phase difference ratio δ (δ1, δ2) / L even after long-term use. Desired. As is clear from the above description, such correction of the equation is performed in a state where torque is input from the engine side to the continuously variable transmission. As in the case of engine brake operation, it is impossible to carry out the torque input to the continuously variable transmission from the drive wheel side. Torque measurement in a state where torque is input to the continuously variable transmission from the drive wheel side is performed based on the phase difference ratio δ (δ1, δ2) / L by the equation corrected as described above.

  In this example, the pair of sensors 7a and 7b is installed only on one gear 4a of the pair of gears 4a and 4b, but another pair of sensors may be installed on the other gear 4b. good. In this case, the reliability regarding the measured value of the said torque T can be improved by calculating | requiring the displacement amount of both these gears 4a and 4b, respectively. In addition, the present embodiment has been described using a device having a pair of gears as a gear transmission device, but the present invention can also be applied to a gear transmission device having a plurality of sets of gears. In this case, it is sufficient to install a pair of sensors on any one of the pair of gears, but it is possible to install a plurality of sets of sensors.

[ First example of reference example related to the present invention ]
FIG. 6 shows a first example of a reference example related to the present invention. In the case of this reference example , the detection part of one sensor 7a of the pair of sensors 7a and 7b is used as the other sensor 7b with respect to the tooth 5a formed at the outer diameter side end of one gear 4a. Are respectively opposed to the teeth 5b formed at the outer diameter side end of the other gear 4b in the radial direction. In the case of the present reference example , the detection portions of the sensors 7a and 7b are positioned 90 ° in the circumferential direction from the meshing portions of the teeth 5a and 5b in the outer peripheral surfaces of the gears 4a and 4b, respectively. Is facing.

Such a structure of this reference example is constituted by the gears 4a and 4b, each of which is a helical gear, and these gears 4a and 4b are relatively displaced in the axial direction when torque is transmitted by the gear transmission device 6. This torque is obtained by utilizing the facts. That is, when the torque is transmitted by the gear transmission device 6, the axial forces Fx (Fx1, Fx2) described above are applied to the gears 4a, 4b in opposite directions according to the torque transmission direction. As a result, the gears 4a and 4b are relatively displaced with respect to the axial direction. And the phase difference which exists between the output signals of the said sensors 7a and 7b shift | deviates from the initial value in the direction according to the transmission direction of the said torque.

  Accordingly, the arithmetic unit that processes the output signals of the sensors 7a and 7b calculates the torque transmitted by the gear transmission device 6 based on the phase difference existing between the output signals of the sensors 7a and 7b. .

In the case of this reference example , when the phase of one sensor 7a is advanced (or delayed), the phase of the other sensor 7b is delayed (or advanced). Therefore, when it is assumed that the magnitude of the torque T transmitted by the gear transmission device 6 is the same, the phase difference δ of the sensors 7a and 7b is set as compared with the case of the first example of the embodiment described above. Can be doubled. Therefore, the gain for obtaining the torque T from the phase difference δ can be increased by about twice, and the measurement accuracy of the torque T can be improved.

  The equation for obtaining the torque T from the amount of displacement obtained based on the phase difference δ (or the phase difference δ itself) is obtained in advance through experiments or the like, as in the first example of the embodiment described above. Keep it.

  Since the configuration and operation of other parts are the same as those of the first example of the above-described embodiment, illustration and description regarding the equivalent parts are omitted.

[ Second example of a reference example related to the present invention ]
FIG. 7 shows a second example of a reference example related to the present invention. In the case of the present reference example, the pair of sensors 7a and 7b are connected to the teeth 5a and 5b of the pair of gears 4a and 4b constituting the gear transmission device 6 rather than in the case of the first example of the reference example described above. It arrange | positions in the position near the meshing part. The sensors 7a and 7b are held by a single holder 9.

According to such a structure of this reference example , the sensors 7a and 7b can be easily installed, and the positional relationship between these sensors 7a and 7b can be regulated with high accuracy. Further, the inclination of the gears 4a and 4b based on the axial force Fx acting on the meshing portion between the teeth 5a and 5b of the gears 4a and 4b exists between the output signals of the sensors 7a and 7b. This contributes to increasing the phase difference δ. Therefore, the gain for obtaining the torque T transmitted by the gear transmission device 6 from the phase difference δ can be increased from the first example of the reference example described above, and the measurement accuracy of the torque T can be improved.

Since the configuration and operation of the other parts are the same as those in the first example of the reference example described above, illustration and description regarding the equivalent parts are omitted.

[ Third example of reference example related to the present invention ]
FIG. 8 shows a third example of the reference example related to the present invention. The first example of the embodiment described above and the first example and the second example of the reference example are all gears based on the axial force Fx among the forces in the respective directions described with reference to FIG. By measuring the displacement, the torque T transmitted by the gear transmission 6 is calculated. On the other hand, in the case of the structure of this reference example , the torque T transmitted by the gear transmission device 6 is measured by measuring the relative displacement of the pair of gears 4a and 4b based on the tangential force Ft (Ft1, Ft2). Is calculated. For this reason, in the case of the present reference example , the detecting portions of the pair of sensors 7a and 7b are used as the meshing portions between the teeth 5a and 5b of the gears 4a and 4b among the outer peripheral surfaces of the gears 4a and 4b. It is made to oppose the 180 degree opposite side position on both sides.

  When transmitting the torque T by the gear transmission device 6, the gears 4a and 4b are tangential to the meshing portion and opposite to each other based on the tangential force Ft (Ft1 and Ft2). Displace. As a result, the phase of the output signal of one sensor 7a advances (or delays), and at the same time, the phase of the output signal of the other sensor 7b delays (or advances), and the output signals of these sensors 7a and 7b are between each other. The existing phase difference changes. Therefore, the transmission direction of the torque T is obtained from the direction in which the phase difference changes, and the magnitude of the torque T is obtained from the amount of change in the phase difference δ.

When the structure for obtaining the torque T based on the tangential force Ft (Ft1, Ft2) is implemented as in this reference example, the gears 4a and 4b are not limited to helical gears. Spur gears may be used. When these gears 4a and 4b are helical gears, the displacement based on the tangential force Ft (Ft1, Ft2) and the displacement due to the axial force Fx (Fx1, Fx2) are combined. Based on this, the torque T is obtained. In the case of a spur gear, the torque T is obtained based only on the displacement by the tangential force Ft (Ft1, Ft2).

  In any case, with respect to the equation for obtaining the torque T from the displacement amount obtained based on the phase difference δ (or the phase difference δ itself), as in the case of the first example of the above-described embodiment, Obtained in advance by experiments or the like.

  Since the configuration and operation of other parts are the same as those of the first example of the above-described embodiment, illustration and description regarding the equivalent parts are omitted.

[ Fourth Reference Example Related to the Present Invention ]
FIG. 9 shows a fourth example of the reference example related to the present invention. This reference example, similarly to the third example of the reference example described above, the tangential force Ft 1 pair of gears 4a based on (Ft1, Ft2), by measuring the relative displacement of the 4b, gear transmission 6 is transmitted The torque T to be calculated is calculated.

However, in the present reference example , the detection portions of the pair of sensors 7a and 7b are set to 180 on the outer peripheral surfaces of the gears 4a and 4b with the meshing portions between the teeth 5a and 5b of the gears 4a and 4b interposed therebetween. Instead of facing the opposite side position, from this position, the pressure angle of the gears 4a, 4b (the radial line of the gear and the tangent line of the tooth surface at one point on the reference circle of the tooth surface of each gear) These gears are opposed to each other at a position further moved in the circumferential direction by an angle formed by The pressure angle is set to a predetermined value within the range of 14.5 ° to 22.5 °, but is usually 20 °.

  More specifically, as shown in FIG. 9, on the reference circle at the meshing portion of these gears 4a and 4b from the position opposite to 180 ° across the meshing portion of the teeth 5a and 5b of the gears 4a and 4b. The sensors 7a and 7b are arranged at positions perpendicular to the common normal α of the tooth surfaces and shifted to β and γ on the lines passing through the rotation centers of the gears 4a and 4b. When the gear 4a pushes the gear 4b, the pushing force at this time acts in a direction on the common normal α of the tooth surfaces of these teeth. For this reason, the relative displacement amount of the gears 4a and 4b is larger in the direction of the common normal α than the tangential direction of the meshing portion between the teeth 5a and 5b of the gears 4a and 4b. Therefore, by shifting the installation position of the sensors 7a and 7b by the pressure angle from the position opposite to the 180.degree. The maximum value of the relative displacement amount of 4b can be detected, and the detection accuracy of the displacement amount in the tangential direction of these gears 4a and 4b can be substantially improved by increasing the detection gain.

In this reference example , in consideration of the direction of the pressure angle when torque is transmitted from the gear 4a to the gear 4b, a pair of sensors 7a in the moving direction corresponding to the rotational direction of the gears 4a and 4b, 7b is shifted, but when it is necessary to consider the case where the rotation direction of these gears 4a and 4b is reversed, the movement direction of these gears 4a and 4b is reversed and the pressure is reversed. Since the direction of the angle is also reversed, in order to improve the accuracy of measurement of the displacement in that direction, from the position opposite 180 ° across the meshing portion of the teeth 5a and 5b of the gears 4a and 4b, It is also possible to dispose a pair of sensors by shifting to the opposite side of the case shown in FIG. 9 by the pressure angle. Further, in order to improve the measurement accuracy of the displacement in both directions, the position of the gear 4a, 4b is moved in the circumferential direction from the opposite side position by 180 ° across the meshing portion of the teeth 5a, 5b. Two pairs of sensors may be installed.

Since the configuration and operation of the other parts are the same as those of the third example of the reference example described above, illustration and description regarding the equivalent parts are omitted.

[ Fifth example of reference example related to the present invention ]
FIG. 10 shows a fifth example of the reference example related to the present invention. In the case of this reference example , the gear transmission is measured by measuring the displacement of the pair of gears 4a, 4b based on the radial force Fr (Fr1, Fr2) among the forces in the respective directions described with reference to FIG. The torque T transmitted by the device 6 is calculated. For this reason, in the case of this reference example , two pairs of sensors 7a to 7d are provided, and the detection parts of these sensors 7a to 7d are used as outer peripheral surfaces of the pair of gears 4a and 4b constituting the gear transmission device 6. Further, a pair of gears 4a and 4b are opposed to each other. The positions where the detection portions of the sensors 7a to 7d face each other are portions that are shifted by 90 ° in the circumferential direction from the meshing portions of the gears 4a and 4b. That is, the detection parts of the pair of sensors 7a and 7b are opposed to two positions on the tangentially opposite side of the meshing part in the outer peripheral surface of one gear 4a. On the other hand, the detection part of another pair of sensors 7c and 7d is opposed to two positions on the tangential opposite side of the meshing part in the outer peripheral surface of the other gear 4b.

In the case of this reference example, the displacement T in the direction in which the gears 4a and 4b are separated from each other is obtained based on the radial force Fr (Fr1, Fr2) generated at the meshing portion, and the torque T is calculated. ing. First, the amount of displacement of the one gear 4a is obtained from the amount of change in the phase difference existing between the output signals of the pair of sensors 7a and 7b. That is, when the one gear 4a is displaced in the away direction, the phase of the output signal of one sensor 7a (or 7b) of the sensors 7a and 7b advances, and the output signal of the other sensor 7b (or 7a). The phase of is delayed. Based on the change in the phase difference δ existing between the output signals of the sensors 7a and 7b, the displacement amount of the one gear 4a can be obtained. Similarly, the amount of displacement of the other gear 4b is also determined based on the amount of change in the phase difference δ existing between the output signals of the other pair of sensors 7c, 7d. Then, the torque T is calculated from the total displacement amount of the gears 4a and 4b, that is, the amount by which the rotation centers of the gears 4a and 4b are separated from each other during torque transmission. The formula for obtaining the torque T from this displacement amount is also obtained in advance by experiments or the like.

In the case of this reference example , the direction of the torque T transmitted by the gear transmission device 6 cannot be known, but the magnitude of the torque T can be obtained. Since the pressing force of the pressing device of the continuously variable transmission can be controlled if the magnitude of the torque T is known, it is not particularly problematic that the direction cannot be known as far as this pressing force control is concerned.

Further, in the case of this reference example , in order to ensure the measurement accuracy of the torque T, the displacement amounts of the gears 4a and 4b are obtained, and the torque T is obtained based on the total of these. Yes. On the other hand, when the measurement accuracy is not so required, the torque T can be calculated from only the displacement amount of one of the gears 4a (or 4b).

  The equation for obtaining the torque T from the amount of displacement obtained based on the phase difference δ (or the phase difference δ itself) is obtained in advance through experiments or the like, as in the first example of the embodiment described above. Keep it.

Since the configuration and operation of the other parts are the same as those of the third example of the reference example described above, illustration and description regarding the equivalent parts are omitted.

[ Second Example of Embodiment]
FIG. 11 shows a second example of an embodiment of the present invention corresponding to claim 2 . In the case of this example, the pair of gears 4a and 4b constituting the gear transmission device 6 are helical gears. In particular, in the case of this example, a pair of spur gears 8a and 8b are provided in a state adjacent to the gears 4a and 4b, respectively. The number of teeth of one gear 4a is the same as the number of teeth of one spur gear 8a, and the number of teeth of the other gear 4b is the same as the number of teeth of the other spur gear 8b. Two pairs of sensors 7a to 7d are provided, and the detection portions of the pair of sensors 7a and 7b are opposed to the outer peripheral surface of one gear 4a and the outer peripheral surface of one spur gear 8a, respectively. On the other hand, the detection parts of another pair of sensors 7c and 7d are opposed to the outer peripheral surface of the other gear 4b and the outer peripheral surface of the other spur gear 8b, respectively. In the case of this example, the sensors 7b and 7d in which the respective detection portions are opposed to the outer peripheral surfaces of the spur gears 8a and 8b are the first example of the above-described embodiment, and the detection portions are opposed to the axial end surfaces of the teeth 5a. It has the role of the sensor 7b.

  Such a structure of this example is a helical gear and is adjacent to the pair of gears 4a and 4b meshed with each other, and has the same number of teeth as those of the gears 4a and 4b. This is effective when spur gears 8a and 8b are provided. A displacement amount in the axial direction of the gear 4a (or 4b) is obtained according to a change in phase difference existing between output signals of the pair of sensors 7a, 7b (or 7c, 7d), and the displacement amount is calculated from the displacement amount. The procedure for calculating the torque T transmitted by the gear transmission device 6 is the same as in the first example of the above-described embodiment. Therefore, it is sufficient to provide this torque T only for one set 7a, 7b (or 7c, 7d) of the sensors 7a to 7d. In this case, only one spur gear 8a (or 8b) is required. It only has to exist.

  Since the configuration and operation of other parts are the same as those of the first example of the above-described embodiment, illustration and description regarding the equivalent parts are omitted.

[ Third example of embodiment]
12 and 13 show a third example of the embodiment of the invention corresponding to claim 3. FIG. In this example, sensor detection is performed on a part of the tooth tip surface of the tooth provided on the outer diameter side end of one or both of the gears of the pair of gears 7a and 7b facing each other. This is characterized in that a groove 10 is provided. In this example, the sensor needs to be positioned in accordance with the sensor detection groove 10, but has the following advantages.

  In the example shown in FIG. 12, the sensor detection groove 10 is formed on each tooth tip surface of the tooth 5c of the spur gear 4c. In the case of a spur gear, the gears do not move relative to each other in the axial direction due to their meshing, but the spur gears move in the axial direction due to the meshing between adjacent helical gears. The gear may be displaced in the axial direction. Since the teeth of the spur gear itself have no torsion angle, even if an axial force Fx (Fx1, Fx2) is applied to the spur gear 4c, the phase of the output signal of the sensor 7a changes based on the axial displacement. There is no. However, in this example, the sensor detection groove 10 is provided with its inclination angle set freely. Therefore, the axial displacement of the spur gear 4c can be detected based on the inclination of the sensor detection groove 10. Such a configuration is suitable when there is no space for the sensors to face each other around the adjacent helical gears themselves.

  In the example shown in FIGS. 13A and 13B, a sensor detection groove 10a or 10b is formed on each tooth tip surface of the tooth 5d of the helical gear 4d. As is apparent from the drawings, the inclination angles of the sensor detection grooves 10a and 10b can be arbitrarily set, and the inclination directions can also be arbitrary. In these examples, first, by independently providing the sensor detection grooves 10a and 10b having an appropriate inclination according to the displacement to be measured regardless of the inclination of the tooth 5d itself of the helical gear 4d, the tooth The displacement of the gear 4d can be measured without being limited by the inclination of the 5d itself. Therefore, the detection gain can be increased without depending on the helical angle of the helical gear set so as to be suitable for power transmission. Further, even when the design accuracy of the tooth 5d itself of the gear 4d is not sufficient or the deterioration of accuracy due to aging occurs, the measurement according to the accuracy of the groove shape is possible without depending on the tooth accuracy. Therefore, displacement detection with higher accuracy is possible.

Since the configuration and operation of other parts are the same as those of the first example of the above-described embodiment, illustration and description regarding the equivalent parts are omitted. In addition, this example can be implemented not only in the first example of the embodiment but also in combination with the second example of the embodiment and the first to fifth examples of the reference example .

[ Sixth Reference Example Related to the Present Invention ]
FIG. 14 shows a sixth example of the reference example related to the present invention. In this reference example , the rotating shaft is axially connected to a rotating shaft in which one or both of the pair of gears, each of which is a helical gear, facing one or both of the detecting portions of the pair of sensors face each other. It is characterized in that it is given elasticity to press with a predetermined force.

  In the example shown in FIG. 14, a bearing 12 that is externally fitted and fixed to an end portion of a rotating shaft 1 a to which a helical gear 4 a is fixed, and that supports the rotating shaft 1 a on a casing 13. In the meantime, a disc spring 11 is provided as an elastic member, and an elastic force pressing in the axial direction is applied to the rotating shaft 1a. For this reason, the outer ring of the bearing 12 is fitted and fixed to a part of the casing 13 so as to be movable in the axial direction. As the elastic member, any member that can press the rotating shaft 1a in the axial direction, such as a coil spring or a resin-made annular member, in addition to the disc spring 11, can be arbitrarily employed.

By providing the elastic member in this manner, the elastic force in the axial direction is applied to the rotating shaft 1a and the helical gear 4a fixed to the rotating shaft 1a regardless of the action of the torque T. When the axial force Fx (Fx1, Fx2) corresponding to the torque T is applied to the helical gear 4a, the axial force Fx (Fx1, Fx2) and the axial elasticity of the elastic member The sum or difference acts on the gear 4a. In this way, in this reference example , the axial rigidity of the rotary shaft 1a that supports the gear 4a by the elastic member is stabilized, and the relationship between the axial displacement of the rotary shaft 1a and the torque T is stabilized. Therefore, more stable torque detection can be realized. Further, by managing the axial rigidity of the rotating shaft 1a supporting the gear 4a with an elastic member, the planned axial displacement of the gear 4a can be realized, so that more accurate torque detection can be realized. .

Since the configuration and operation of other parts are the same as those of the first example of the above-described embodiment, illustration and description regarding the equivalent parts are omitted. This reference example can be implemented not only in the first example of the embodiment but also in combination with the second example, the third example of the embodiment, and the first to sixth examples of the reference example. .

  The physical quantity measuring device for a gear transmission device of the present invention is not limited to the case of measuring torque passing through a continuously variable transmission used as an automatic transmission for automobiles, but various machine devices incorporating a gear transmission device such as a machine tool. Can be used to measure the torque transmitted by Further, the present invention can also be implemented with respect to a gear transmission device that meshes bevel gears that are respectively fixed to the ends of a pair of rotating shafts that are arranged in a direction crossing each other.

1, 1a, 1b Rotating shaft 2a, 2b Encoder 3a, 3b Sensor 4a, 4b Gear 5a, 5b Teeth 6 Gear transmission device 7a, 7b, 7c, 7d Sensor 8a, 8b Spur gear 9 Holder 10, 10a, 10b For sensor detection Groove 11 disc spring 12 bearing 13 casing

Claims (3)

A pair of rotating shafts and a part of each of these rotating shafts are fixed to each other, and the teeth formed on the respective outer diameter side end portions are engaged with each other, whereby torque between these rotating shafts can be reduced. A gear transmission device comprising at least a pair of gears capable of transmission;
Each detection unit is opposed to a tooth provided at an end portion on the outer diameter side of at least one of the pair of gears, thereby changing an output signal as the gear rotates. With sensors,
Based on the phase difference that exists between the output signals of the sensors, an arithmetic unit that calculates a physical quantity related to the gear that faces the detection unit of each sensor;
Equipped with a,
The pair of gears are helical gears, and the detection part of one of the pair of sensors is formed on a tooth formed on an outer diameter side end of one of the pair of gears. On the other hand, in the radial direction, the detection part of the other sensor is opposed to the teeth formed at the outer diameter side end of the one gear in the axial direction, and the computing unit outputs the sensor A gear quantity measuring device physical quantity measuring device that calculates at least one of an axial displacement amount of the one gear and a torque transmitted by the gear based on a change in phase difference existing between signals . A pair of rotating shafts and a part of each of these rotating shafts are fixed to each other, and the teeth formed on the respective outer diameter side end portions are engaged with each other, whereby torque between these rotating shafts can be reduced. A gear transmission device comprising at least a pair of gears capable of transmission;
Each detection unit is opposed to a tooth provided at an end portion on the outer diameter side of at least one of the pair of gears, thereby changing an output signal as the gear rotates. With sensors,
Based on the phase difference that exists between the output signals of the sensors, an arithmetic unit that calculates a physical quantity related to the gear that faces the detection unit of each sensor;
Equipped with a,
The pair of gears is a helical gear, and the detection part of one of the pair of sensors is connected to a tooth formed on the outer diameter side end of one of the gears. Opposite to the radial direction, the detection part of the other sensor faces the teeth formed on the outer diameter side end of the spur gear fixed to the same rotating shaft as this one gear adjacent to this one gear. And the computing unit is based on a phase difference existing between the output signals of the pair of sensors, and at least one of an axial displacement amount of the one gear and a torque transmitted by the gear. A physical quantity measuring device for a gear transmission device that calculates one . A pair of rotating shafts and a part of each of these rotating shafts are fixed to each other, and the teeth formed on the respective outer diameter side end portions are engaged with each other, whereby torque between these rotating shafts can be reduced. A gear transmission device comprising at least a pair of gears capable of transmission;
Each detection unit is opposed to a tooth provided at an end portion on the outer diameter side of at least one of the pair of gears, thereby changing an output signal as the gear rotates. With sensors,
Based on the phase difference that exists between the output signals of the sensors, an arithmetic unit that calculates a physical quantity related to the gear that faces the detection unit of each sensor;
Equipped with a,
Among the pair of gears, a sensor detection groove is provided on a part of the tooth tip surface of the tooth provided on the outer diameter side end of the gear facing the detection unit of the pair of sensors. gear transmission for a physical quantity measuring device are.

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