JP2012137194A - Planetary roller type traction drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planetary roller type traction drive which can detect the generation of a fine crack, can take measures in an early stage, and is high in reliability.SOLUTION: The planetary roller type traction drive 1 includes: a plurality of planetary roller 5 which are arranged around a sun roller 3 so as to be able to rotate/revolve; a ring roller 7 which is arranged outside the plurality of planetary rollers 5 and sandwiches the planetary rollers 5 together with the sun roller 3; a sun shaft 9 concentrically fixed to the sun roller 3; a carrier 11 which rotatably supports the respective planetary rollers 5; a carrier support shaft 13 which is fixedly attached to the carrier 11 and located coaxially with the carrier; and a drive motor 47 which drives either of the sun shaft 9 or the carrier support shaft 13. The planetary roller type traction drive is also characterized in that the fine crack generated at the ring roller 7 is detected by an ammeter (detection member) 49 arranged at the drive motor 47, or a shaft torque meter (detection member) 51 arranged at the carrier support shaft 13.

Description

  The present invention relates to a planetary roller traction drive.

The planetary roller type traction drive has a structure in which a plurality of planetary rollers arranged on the peripheral surface of the sun roller are sandwiched between a sun roller and a ring roller arranged outside the sun roller. The planetary roller is supported by a planetary roller shaft fixed to the carrier at equal intervals in the circumferential direction via a rolling bearing, and can revolve and rotate around the sun roller.
A shaft (carrier support shaft, sun shaft) that is rotatably supported is fixed to the carrier and the sun roller. The power input to one of these shafts is transmitted to the other shaft via the sun roller, the planetary roller, and the ring roller. (For example, see Patent Document 1.)

This planetary roller type traction drive has an oil film shear force generated by applying a normal force (force in the normal direction) to the contact portion of the sun roller, planetary roller, and ring roller in contact with each other through the oil film. The power is transmitted by means of.
The planetary roller traction drive that does not have such limitations is a high rotation accuracy and low noise compared to the gear type, which is based on the meshing of teeth and has a limitation in production technology for improving rotational accuracy. High efficiency.
For this reason, the planetary roller type traction drive is widely used in drive systems in various industrial machine fields, mainly in fields where relatively high torque is not required.

By the way, in order to shear the oil film, it is necessary to apply a normal force between the rollers. The normal force is generally applied by pushing the ring roller in the radial direction. The pressing by the conventional ring roller is performed using, for example, elastic deformation of the ring roller. That is, the cross section is U-shaped open to the outside, and the inner diameter of the ring roller is made smaller than the outer position of the planetary roller. The normal force is given.
Further, after the ring roller is mounted on the outer side of the planetary roller, both U-shaped side surfaces are pressed, the inner peripheral surface in contact with the planetary roller is deformed by crowning, and the inner diameter of the ring roller is uniformly reduced. Since the amount of deformation is restricted only at the contact portion with the planetary roller, a normal force is applied between the rollers.

JP-A-9-203449

By the way, in the planetary roller type traction drive, the ring roller periodically contacts the planetary roller during operation, a tensile force is applied when the ring roller is in contact, and a compression force is applied when the ring roller is not in contact.
The ring roller receives a tensile force and a compressive force alternately and repeatedly by the planetary roller in a state where a large tensile force is acting as an initial condition, so that the ring roller is cracked due to being formed of a hard material. Sometimes.
If the ring roller breaks, even if it is partial, the debris can bite between the rollers and cause significant damage.

In such a situation, the planetary roller type traction drive does not perform the power transmission function, so that the industrial machine using it suddenly stops and has a great influence.
Further, if the damage is large, it takes a lot of time to repair the planetary roller type traction drive, and the production stop time becomes long.
For this reason, it is required to detect that the ring roller is in a cracked state at an early stage, for example, in the state of a microcrack, and to be able to take measures such as repairing at an early stage.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a highly reliable planetary roller traction drive capable of detecting the occurrence of microcracks and enabling early response.

In order to solve the above problems, the present invention employs the following means.
A planetary roller type traction drive according to the present invention includes a plurality of planetary rollers arranged around a sun roller so as to be capable of rotating and revolving, and arranged outside the plurality of planetary rollers, and sandwiching the planetary roller together with the sun roller. A ring roller that is concentrically fixed to the sun roller, a carrier that rotatably supports the planetary rollers, and a carrier support shaft that is fixedly attached to the carrier and is coaxial with the carrier roller. A planetary roller traction drive having a drive motor that drives one of the sun shaft or the carrier support shaft, and a detection member that detects that a microcrack has occurred in the ring roller, The detection member is an ammeter attached to the drive motor and detecting a motor current of the drive motor. It is characterized in.

  Thus, since the detection member which detects that the micro crack generate | occur | produced in the ring roller is provided, if a micro crack generate | occur | produces in a ring roller, a detection member can detect it. Thus, since the detection member can detect in the state of a micro crack, it can prevent that a planetary roller type traction drive is damaged greatly. As a result, since it is possible to take measures such as repair at an early stage, the influence on the industrial machine or the like using the planetary roller traction drive can be minimized, and the reliability can be improved.

The detection member may always detect a crack during operation, or may be detected intermittently when the operation is stopped.
In this configuration, when a crack occurs in the ring roller, the rigidity of the ring roller changes, and the pressing force of the ring roller against the planetary roller changes. Along with this, the shaft torque acting on the sun shaft and the carrier support shaft changes, and the load of the drive motor that drives the sun shaft changes, so the motor current that operates the drive motor changes. For this reason, the level of the motor current measured by the ammeter attached to the drive motor as the detection member changes, and when this change occurs, it is determined that a crack has occurred.

  The planetary roller traction drive according to the present invention includes a plurality of planetary rollers arranged around the sun roller so as to be capable of rotating and revolving, and arranged outside the plurality of planetary rollers, and the planetary roller together with the sun roller. A ring roller that sandwiches the sun roller, a sun shaft that is concentrically fixed to the sun roller, a carrier that rotatably supports each planetary roller, and a carrier support that is fixedly attached to the carrier and is coaxial with the carrier A planetary roller traction drive having a shaft, and a detection member for detecting that a microcrack has occurred in the ring roller, the detection member being provided on one of the sun shaft and the carrier support shaft. A shaft that is attached and detects a change in shaft torque of the sun shaft or the carrier support shaft over time Characterized in that it is a torque meter.

  In this configuration, when a crack occurs in the ring roller, the rigidity of the ring roller changes, and the pressing force of the ring roller against the planetary roller changes. Along with this, the shaft torque acting on the sun shaft and the carrier support shaft changes, and the change in the shaft torque is detected by the shaft torque meter, and it is determined that a crack has occurred.

According to the planetary roller type traction drive according to the present invention, since the detection member for detecting the occurrence of the minute crack in the ring roller is provided, the detection member can detect the occurrence of the minute crack in the ring roller. .
As a result, the planetary roller traction drive can be prevented from being greatly damaged, and repairs and the like can be taken at an early stage, so that the reliability can be improved.

1 is a cross-sectional view of a planetary roller traction drive according to a first reference embodiment of the present invention. It is XX sectional drawing of FIG. It is a block diagram which shows the electrical resistance detection apparatus concerning 1st reference embodiment of this invention. It is a cross-sectional view of the ring roller part concerning 2nd reference embodiment of this invention. It is a graph which shows the change of the vibration acceleration of the ring roller concerning 2nd reference embodiment of this invention. It is a cross-sectional view of the ring roller part concerning 3rd reference embodiment of this invention. It is a cross-sectional view of the ring roller part concerning 4th reference embodiment of this invention. It is a cross-sectional view which shows another embodiment of the ring roller part concerning 4th reference embodiment of this invention. It is a cross-sectional view of a ring roller portion according to a fifth reference embodiment of the present invention. It is a schematic diagram which shows typically the planetary roller type traction drive concerning 6th reference embodiment of this invention. It is a graph which shows the change of the output rotational speed concerning 6th reference embodiment of this invention. It is sectional drawing which shows the planetary roller type traction drive concerning embodiment of this invention. It is a graph which shows the change of the motor current concerning embodiment of this invention. It is a graph which shows the change of the axial torque concerning embodiment of this invention. It is sectional drawing which shows the planetary roller type traction drive concerning 7th reference embodiment of this invention. It is a graph which shows the change of the axial runout concerning 7th reference embodiment of this invention. It is a cross-sectional view of the ring roller portion according to the eighth reference embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Reference Embodiment]
A planetary roller traction drive 1 according to a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows a cross-sectional view of a planetary roller traction drive 1. FIG. 2 is a sectional view taken along line XX in FIG.

  The planetary roller traction drive 1 includes a sun roller 3, a plurality of, for example, three planet rollers 5, a ring roller 7, a sun shaft 9 concentrically fixed to the end surface of the sun roller 3, and each planet. A carrier 11 that rotatably supports each of the rollers 5 and a carrier support shaft 13 that is fixedly attached to the carrier 11 and is coaxial with the carrier 11 are provided.

  The sun roller 3 is a roller formed of, for example, carburized steel, and the hardness thereof is 60 or more in Rockwell hardness (HRC). The sun shaft 9 is rotatably supported by a frame (not shown).

  The planetary roller 5 is, for example, a hollow cylindrical body made of bearing steel, and the hardness thereof is 60 or more in Rockwell hardness (HRC). The planetary rollers 5 are supported by planetary roller shafts 15 fixed to the carrier 11 at equal intervals in the circumferential direction via rolling bearings 17 so as to be in contact with the periphery of the sun roller 3. The carrier support shaft 13 is rotatably supported by a frame (not shown). For this reason, the planetary roller 5 can revolve around the sun roller 3 and can rotate.

The ring roller 7 is a ring body made of bearing steel, for example, and the hardness thereof is 60 or more in Rockwell hardness (HRC).
The cross-sectional shape of the ring roller 7 is U-shaped. The inner diameter of the ring roller 7 is made larger than the envelope formed by the outer ends of the plurality of planetary rollers 5.
After the ring roller 7 is inserted in the axial direction outside the plurality of planetary rollers 5, a preload F is applied to both side surfaces thereof. Thereby, crowning deformation is formed on the inner peripheral surface of the ring roller 7, and the inner diameter of the ring roller 7 is uniformly reduced. Since this deformation amount is constrained only by the contact portion with the planetary roller 7, the contact portion between the ring roller 7 and the planetary roller 5 and the contact portion between the planetary roller 5 and the sun roller 3 are based on this. A normal force is generated in proportion to the preload F. Therefore, by adjusting the preload F, the normal force acting between the rollers can be arbitrarily and accurately set.

FIG. 3 is a block diagram showing the electrical resistance detection device (detection member) 19.
The electrical resistance detection device 19 includes a voltmeter 21, a DC power source 23, and a resistor 25. The voltmeter 21, the DC power source 23, and the resistor 25 are connected in series to a connection connecting two points of the ring roller 7. In other words, the voltmeter 21, the DC power source 23, the resistor 25, and the ring roller 7 are connected in series.
Since the resistor 25 has a constant resistance value, the voltage measured by the voltmeter 21 varies depending on the resistance of the ring roller 7.

The planetary roller traction drive 1 configured as described above operates as follows.
When the planetary roller traction drive 1 is used as a speed reducer, the sun shaft 9 is used as an input shaft, and the ring roller 7 is fixed. Thus, the rotation of the sun shaft 9 is transmitted to each planetary roller 5 through the sun roller 3. As the planetary roller 5 rotates between the sun roller 3 and the ring roller 7, the planetary roller 5 revolves around the sun roller 3.
Since the carrier 11 is rotated by the revolution of the planetary roller 5, the decelerated rotation is transmitted to the carrier support shaft 13 that is an output shaft.

  When the planetary roller type traction drive 1 is used as a speed increaser, the ring roller 7 is fixed, and on the contrary, the carrier support shaft 13 is used as an input shaft and the sun shaft 9 is used as an output shaft. Since the rotation of the carrier support shaft 13 is transmitted from the carrier 11 and the planetary roller shaft 15 to the planetary roller 5, the planetary roller 5 is accelerated by rotating between the sun roller 3 and the ring roller 7, and the sun roller 3 is transmitted to the sun axis 9.

At this time, if a crack occurs in the ring roller 7, the shape of the ring roller 7 changes or the electrical resistance of the ring roller 7 changes due to contact with other members.
When the electrical resistance of the ring roller 7 changes, the detection value of the voltmeter of the electrical resistance detector 19 changes. Therefore, when the voltage measured by the electrical resistance detector 19 changes, it can be determined that a crack has occurred.
Since the electrical resistance detection device 19 can always measure even during operation, it can determine the occurrence of cracks in the ring roller 7 at an earlier stage. Therefore, it is possible to grasp the occurrence of cracks in a more microcrack state.

Thus, since the electrical resistance detection apparatus 19 can detect in the state of a micro crack, it can prevent that the planetary roller type traction drive 1 is damaged greatly.
As a result, the planetary roller type traction drive 1 can be repaired at an early stage, so that the influence on the industrial machine using the planetary roller type traction drive 1 can be minimized, and the reliability can be improved. Can be improved.
In addition, since the electrical resistance detection apparatus 19 is illustrated, various means can be used as a means for measuring a change in the electrical resistance of the ring roller 7.

[Second Reference Embodiment]
Next, a second reference embodiment of the present invention will be described using FIG. 4 and FIG.
In this second reference embodiment, the method for detecting cracks in the ring roller 7 is different from that in the first reference embodiment. Therefore, this different part will be mainly described here, and the same as in the first reference embodiment described above. A duplicate description of the portion is omitted.
In addition, the same code | symbol is attached | subjected to the same member as 1st reference embodiment.

FIG. 4 is a cross-sectional view of the ring roller 7 part. FIG. 5 is a graph showing changes in vibration acceleration of the ring roller 7.
In the present embodiment, an accelerometer (detection member) 27 is attached to the back surface of the ring roller 7.
The accelerometer 27 detects the acceleration when the ring roller 7 vibrates.
For the vibration acceleration detected by the accelerometer 27, the mean square value (rms value) of the acceleration measured at the start of driving is set as an initial state.

At this time, if a crack occurs in the ring roller 7, the rigidity of the ring roller 7 changes. When the rigidity of the ring roller 7 changes, the pressing force of the ring roller 7 against the planetary roller 5 changes. As a result, the passing state of the planetary roller 5 changes, so that the vibration state of the ring roller 7 changes.
Accordingly, as shown in FIG. 5, the level of acceleration measured by the accelerometer 27 changes. When this change occurs, it is determined that a crack 31 has occurred.
Since the accelerometer 27 can always measure even during operation, the occurrence of cracks in the ring roller 7 can be determined earlier. Therefore, it is possible to grasp the occurrence of cracks in a more microcrack state.

Thus, since the accelerometer 27 can detect in the state of a micro crack, it can prevent that the planetary roller type traction drive 1 is damaged greatly.
As a result, the planetary roller type traction drive 1 can be repaired at an early stage, so that the influence on the industrial machine using the planetary roller type traction drive 1 can be minimized, and the reliability can be improved. Can be improved.
In the present embodiment, the accelerometer 27 that measures the acceleration of vibration is used. However, a displacement meter that measures the displacement of vibration may be used, or the amplitude of vibration may be measured. .

[Third embodiment]
Next, a third reference embodiment of the present invention will be described with reference to FIG.
In the third reference embodiment, the method for detecting cracks in the ring roller 7 is different from that in the first reference embodiment. Therefore, here, this different part will be mainly described and the same as in the first reference embodiment described above. A duplicate description of the portion is omitted.
In addition, the same code | symbol is attached | subjected to the same member as 1st reference embodiment.

FIG. 6 is a cross-sectional view of the ring roller 7 part.
In the present embodiment, an accelerometer (detection member) 27 is attached to the side surface of the ring roller 7.
The accelerometer 27 detects the acceleration when the ring roller 7 vibrates. The accelerometer 27 measures, for example, the acceleration of vibration when the ring roller 7 vibrates, that is, the vibration eigenvalue of the ring roller 7 while the operation is stopped.

When a crack occurs in the ring roller 7, the rigidity of the ring roller 7 changes. When the rigidity of the ring roller 7 changes, the vibration eigenvalue of the ring roller 7 changes.
When this change occurs, it is determined that a crack has occurred.

Thus, since the accelerometer 27 can detect in the state of a micro crack, it can prevent that the planetary roller type traction drive 1 is damaged greatly.
As a result, the planetary roller type traction drive 1 can be repaired at an early stage, so that the influence on the industrial machine using the planetary roller type traction drive 1 can be minimized, and the reliability can be improved. Can be improved.

[Fourth embodiment]
Next, a fourth reference embodiment of the present invention will be described with reference to FIGS.
In the fourth reference embodiment, the method for detecting cracks in the ring roller 7 is different from that in the first reference embodiment. Therefore, this different part will be mainly described here and the same as that in the first reference embodiment described above. A duplicate description of the portion is omitted.
In addition, the same code | symbol is attached | subjected to the same member as 1st reference embodiment.

7 and 8 are cross-sectional views of the ring roller 7 part.
In this embodiment, as shown in FIG. 7, a stress paint film (detection member) 35 is applied to the back surface of the ring roller 7, which generates a crack when the stress changes. Further, as shown in FIG. 8, a strain gauge (detection member) 37 for measuring stress is attached to the back surface of the ring roller 7.
In other words, the stress paint film 35 and the strain gauge 37 detect changes in the stress of the ring roller 7.

When a crack occurs in the ring roller 7, the rigidity of the ring roller 7 changes. When the rigidity of the ring roller 7 changes, the stress of the ring roller 7 changes.
When this change occurs, it is determined that a crack has occurred.

Thus, since the stress paint film 35 or the strain gauge 37 can be detected in the state of a micro crack, the planetary roller traction drive 1 can be prevented from being greatly damaged.
As a result, the planetary roller type traction drive 1 can be repaired at an early stage, so that the influence on the industrial machine using the planetary roller type traction drive 1 can be minimized, and the reliability can be improved. Can be improved.

[Fifth Reference Embodiment]
Next, a fifth reference embodiment of the present invention will be described with reference to FIG.
In the fifth reference embodiment, the method for detecting cracks in the ring roller 7 is different from that in the first reference embodiment. Therefore, this different part will be mainly described here and the same as that in the first reference embodiment described above. A duplicate description of the portion is omitted.
In addition, the same code | symbol is attached | subjected to the same member as 1st reference embodiment.

FIG. 9 is a cross-sectional view of the ring roller 7 part.
In the present embodiment, a defect detection device (detection member) 39 by ultrasonic flaw detection is attached to the side surface of the ring roller 7.
The defect detection device 39 can detect whether the ring roller 7 has a defect such as a crack by ultrasonic flaw detection.

Thus, since the defect detection apparatus 39 can detect in the state of a microcrack, it can prevent that the planetary roller type traction drive 1 is damaged greatly.
As a result, the planetary roller type traction drive 1 can be repaired at an early stage, so that the influence on the industrial machine using the planetary roller type traction drive 1 can be minimized, and the reliability can be improved. Can be improved.

[Sixth embodiment]
Next, a sixth reference embodiment of the present invention will be described with reference to FIGS. 10 and 11.
In the sixth reference embodiment, the method for detecting cracks in the ring roller 7 is different from that in the first reference embodiment. Therefore, this different part will be mainly described here and the same as that in the first reference embodiment described above. A duplicate description of the portion is omitted.
In addition, the same code | symbol is attached | subjected to the same member as 1st reference embodiment.

FIG. 10 is a cross-sectional view showing a portion similar to FIG. 2 of the planetary roller traction drive 1 according to the present embodiment. FIG. 11 is a graph showing changes in the output rotation speed.
In this embodiment, a speedometer (detection member) 41 that detects the rotational speed (rotation number) of the input shaft, for example, the sun shaft 9, is provided on the output shaft, for example, the carrier support shaft 13, of the rotational speed (rotation number). A speedometer (detection member) 43 for detecting the above is attached. Usually, since the input rotational speed is often operated at a constant value, the rotational speed may be measured only by the speedometer 43. FIG. 11 shows changes in the output rotation speed measured by the speedometer 43.

At this time, if a crack occurs in the ring roller 7, the rigidity of the ring roller 7 changes. When the rigidity of the ring roller 7 changes, the pressing force of the ring roller 7 against the planetary roller 5 changes. Accordingly, since the passing state of the planetary roller 5 changes, the ratio of the output rotation speed to the input rotation speed changes.
Accordingly, as shown in FIG. 11, the level of the rotational speed measured by the speedometer 43 changes. When this change 45 occurs, it is determined that a crack has occurred.
Since the speedometers 41 and 43 can always measure during operation, the occurrence of cracks in the ring roller 7 can be determined earlier. Therefore, it is possible to grasp the occurrence of cracks in a more microcrack state.

Thus, since the speedometers 41 and 43 can detect in the state of a micro crack, it can prevent that the planetary roller type traction drive 1 is damaged greatly.
As a result, the planetary roller type traction drive 1 can be repaired at an early stage, so that the influence on the industrial machine using the planetary roller type traction drive 1 can be minimized, and the reliability can be improved. Can be improved.

[Embodiment]
Next, an embodiment of the present invention will be described with reference to FIGS.
In this embodiment, since the method for detecting cracks in the ring roller 7 is different from that in the first reference embodiment, this different part will be mainly described here, and the same part as that in the first reference embodiment described above will be described. A duplicate description is omitted.
In addition, the same code | symbol is attached | subjected to the same member as 1st reference embodiment.

FIG. 12 is a cross-sectional view showing a portion similar to FIG. 2 of the planetary roller traction drive 1 according to the present embodiment.
In the present embodiment, the input shaft, for example, the sun shaft 9 is provided with a drive motor 47 that rotationally drives it. An ammeter (detection member) 49 for detecting the motor current is attached to the drive motor 47.
FIG. 13 shows the change of the motor current measured by the ammeter 49 with time.

A shaft torque meter (detection member) 51 for measuring the shaft torque of the carrier support shaft 13 is attached to the output shaft, for example, the carrier support shaft 13.
FIG. 14 shows the change of the shaft torque of the carrier support shaft 13 measured by the shaft torque meter 51 with the passage of time.
Only one of the ammeter 49 and the shaft torque meter 51 may be attached. The shaft torque meter 51 may be attached to the sun shaft 9 instead of the carrier support shaft 13.

At this time, if a crack occurs in the ring roller 7, the rigidity of the ring roller 7 changes. When the rigidity of the ring roller 7 changes, the pressing force of the ring roller 7 against the planetary roller 5 changes. As a result, the passing state of the planetary roller 5 changes, so that the shaft torque acting on the carrier support shaft 13 and the sun shaft 9 changes.
Along with this, as shown in FIG. 14, the level of the shaft torque of the carrier support shaft 13 measured by the shaft torque meter 51 changes. When this change 55 occurs, it is determined that a crack has occurred.
When the shaft torque acting on the sun shaft 9 changes, the load of the drive motor 47 that drives the sun shaft 9 changes, so the motor current that operates the drive motor 47 changes.
Accordingly, as shown in FIG. 13, the level of the motor current measured by the ammeter 49 changes. When this change 53 occurs, it is determined that a crack has occurred.

Since the ammeter 49 and the shaft torque meter 51 can always measure during operation, the occurrence of cracks in the ring roller 7 can be determined earlier. Therefore, it is possible to grasp the occurrence of cracks in a more microcrack state.
Thus, since the ammeter 49 and / or the shaft torque meter 51 can be detected in a microcrack state, the planetary roller traction drive 1 can be prevented from being greatly damaged.
As a result, the planetary roller type traction drive 1 can be repaired at an early stage, so that the influence on the industrial machine using the planetary roller type traction drive 1 can be minimized, and the reliability can be improved. Can be improved.

[Seventh embodiment]
Next, a seventh reference embodiment of the present invention will be described with reference to FIGS. 15 and 16.
In the seventh reference embodiment, the method for detecting cracks in the ring roller 7 is different from that in the first reference embodiment. Therefore, this different part will be mainly described here and the same as that in the first reference embodiment described above. A duplicate description of the portion is omitted.
In addition, the same code | symbol is attached | subjected to the same member as 1st reference embodiment.

FIG. 15 is a cross-sectional view showing a portion similar to FIG. 2 of the planetary roller traction drive 1 according to the present embodiment.
In this embodiment, a displacement meter (detection member) 57 that detects the displacement in the radial direction is attached to the output shaft, for example, the carrier support shaft 13. The displacement meter 57 measures the amount of movement of the carrier support shaft 13 in the radial direction (the direction along the paper surface of FIG. 15) in contact or non-contact with the carrier support shaft 13 from the radial direction.
FIG. 16 shows the change of the shaft runout of the carrier support shaft 13 measured with the displacement meter 57 over time.
The displacement meter 57 may be attached to the input shaft, for example, the sun shaft 9.

At this time, if a crack occurs in the ring roller 7, the rigidity of the ring roller 7 changes. When the rigidity of the ring roller 7 changes, the pressing force of the ring roller 7 against the planetary roller 5 changes. Along with this, the passing state of the planetary roller 5 changes, so that the axial torque acting on the carrier support shaft 13 and the sun shaft 9 changes, and they easily swing in the radial direction.
Along with this, as shown in FIG. 16, the level of shaft runout of the carrier support shaft 13 measured by the displacement meter 57 changes. When this change 59 occurs, it is determined that a crack has occurred.
Since the displacement meter 57 can always measure during operation, the occurrence of cracks in the ring roller 7 can be determined earlier. Therefore, it is possible to grasp the occurrence of cracks in a more microcrack state.

Thus, since the displacement meter 57 can detect in the state of a micro crack, it can prevent that the planetary roller type traction drive 1 is damaged greatly.
As a result, the planetary roller type traction drive 1 can be repaired at an early stage, so that the influence on the industrial machine using the planetary roller type traction drive 1 can be minimized, and the reliability can be improved. Can be improved.

[Eighth Reference Embodiment]
Next, an eighth reference embodiment of the present invention will be described with reference to FIG.
In the eighth reference embodiment, the method for detecting cracks in the ring roller 7 is different from that in the first reference embodiment. Therefore, this different part will be mainly described here and the same as that in the first reference embodiment described above. A duplicate description of the portion is omitted.
In addition, the same code | symbol is attached | subjected to the same member as 1st reference embodiment.

FIG. 17 is a cross-sectional view of the ring roller 7 part.
In the present embodiment, an AE detection device (detection member) 61 is attached to the ring roller 7. The AE detection device 61 includes an AE sensor 63 that detects an elastic wave generated by the ring roller 7 attached to the side surface of the ring roller 7 and an AE measuring instrument 65 that visualizes a signal detected by the AE sensor.

When a crack occurs in the ring roller 7, the ring roller 7 generates a so-called acoustic emission in which the strain energy stored therein is released as an elastic wave.
When acoustic emission occurs, the AE sensor 63 detects it, and the AE measuring device 65 visualizes and notifies the detection of acoustic emission.
When this acoustic emission occurs, it is determined that a crack has occurred.
Since the AE detection device 61 can always measure even during operation, it can determine the occurrence of cracks in the ring roller 7 at an earlier stage. Therefore, it is possible to grasp the occurrence of cracks in a more microcrack state.

Thus, since the AE detection device 61 can detect in the state of a microcrack, the planetary roller traction drive 1 can be prevented from being greatly damaged.
As a result, the planetary roller type traction drive 1 can be repaired at an early stage, so that the influence on the industrial machine using the planetary roller type traction drive 1 can be minimized, and the reliability can be improved. Can be improved.

  In addition, this invention is not limited to said each embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

DESCRIPTION OF SYMBOLS 1 Planetary roller type traction drive 3 Sun roller 5 Planet roller 7 Ring roller 9 Sun shaft 11 Carrier 13 Carrier support shaft 19 Electrical resistance detection device 27 Accelerometer 35 Stress paint film 37 Strain gauge 39 Defect detection device 41 Speed meter 43 Speed meter 45 AE detector 47 Drive motor 49 Ammeter (detection member)
51 Axis torque meter (detection member)

Claims (2)

A plurality of planetary rollers arranged to rotate and revolve around the sun roller;
A ring roller disposed outside the plurality of planetary rollers and sandwiching the planetary roller together with the sun roller;
A sun shaft concentrically fixed with the sun roller;
A carrier that rotatably supports each of the planetary rollers,
A carrier support shaft fixedly attached to the carrier and coaxial therewith;
A drive motor for driving one of the sun shaft or the carrier support shaft;
A planetary roller traction drive equipped with
A detection member for detecting the occurrence of micro cracks in the ring roller is provided,
The detection member is
A planetary roller traction drive characterized by being an ammeter attached to the drive motor and detecting a motor current of the drive motor. A plurality of planetary rollers arranged to rotate and revolve around the sun roller;
A ring roller disposed outside the plurality of planetary rollers and sandwiching the planetary roller together with the sun roller;
A sun shaft concentrically fixed with the sun roller;
A carrier that rotatably supports each of the planetary rollers,
A carrier support shaft fixedly attached to the carrier and coaxial therewith;
A planetary roller traction drive equipped with
A detection member for detecting the occurrence of micro cracks in the ring roller is provided,
The detection member is
A planetary roller type traction drive which is attached to one of the sun shaft or the carrier support shaft and detects a change with time in the shaft torque of the sun shaft or the carrier support shaft. .

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