JP2013250204A - Load measuring device and measuring method for pin type holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load measuring device and a measuring method for a pin type holder that can calculate force acting on a pin more accurately and also predict breakage of a pin more accurately.SOLUTION: A measurement is taken by a load measuring device for a pin type holder that includes a fixed part 4 which is fixed to an annular part 1 having a through hole, a shaft part 41 which extends in a pin insertion hole 55 from the fixed part 4 to a position of a conic roll 32 before the extension-directional center of the pin insertion hole 55, an annular flange part 42 which extends from an outer peripheral surface of the shaft part 41 outwardly in a radial direction of the shaft part 41, and comes into contact with an inner peripheral surface of the pin insertion hole 55 to be loaded from the inner peripheral surface, and a strain gauge 5 which is fixed to the outer peripheral surface of the shaft part 41. Then matching between measured values and a model is performed to predict a distribution of strains generated in a pin.

Description

  The present invention relates to a load measuring device and a measuring method for a pin type cage.

  Conventionally, as a load measuring device for measuring a load applied to a bearing component, there is one described in JP 2011-149538 A (Patent Document 1). This load measuring device measures the load received by the rollers held by the pin type cage. The load measuring device includes a strain gauge, a position sensor, and a data logger, and the strain gauge is attached to the inner peripheral surface of the through hole of the roller.

  This load measuring device detects the load applied to the roller with a strain gauge and records / accumulates the detection signal in the data logger, and the position sensor records the detection signal in the data logger. The rotation position in the revolution direction of the drum can be detected. Since this load measuring apparatus can make the detection signal detected by the strain gauge correspond to the rotational position of the roller in the revolution direction, the reliability of the analysis result can be improved.

  However, in the conventional load measuring device, since the distortion of the inner surface of the through hole of the roller is detected, the force acting on the pin cannot be measured, and the analysis based on the force cannot be performed. However, there is a problem in that it is impossible to predict the pin breakage that has occurred chronically for many years.

  Also, even if other devices try to measure the force acting on the pins, the sensor mounting part is inside the bearing, and the sensor mounting destination is a rotating body such as a cage, making data output complicated. For this reason, there is a problem that actual measurement has not been realized.

  In addition, depending on the contact state between the pin and the inner diameter of the hollow roller, a large number of measurement output patterns can be considered even with the same acting force, and there is a problem that an analysis method has not been established because detection is difficult.

  Therefore, it is difficult to actually measure and analyze the force acting on the pin of the pin type cage, and there is currently no means for actually measuring the force acting on the pin.

JP 2011-149538 A

  Therefore, an object of the present invention is to provide a load measuring device and a measuring method for a pin type cage that can calculate the force acting on the pin of the pin type cage more accurately and can predict the breakage of the pin more accurately. It is in.

In order to solve the above problems, the load measuring device for the pin type cage of the present invention is:
A fixed portion fixed to an annular portion having a through hole;
A shaft portion that can extend from the fixed portion into the pin insertion hole of the roller;
An annular flange portion extending from the outer peripheral surface of the shaft portion to the outer side in the radial direction of the shaft portion and positioned in the inner peripheral surface of the pin insertion hole and capable of contacting the inner peripheral surface; ,
And a load sensor fixed to the outer peripheral surface of the shaft portion.

  According to the present invention, the portion in contact with the roller is the edge of the annular flange portion, so that contact close to point contact can be realized between the roller and the flange portion, and a point load (concentrated load) is applied to the flange portion. ) Can be applied. Therefore, the pin strain distribution model can be simplified and the boundary condition in the model can be determined more accurately. Therefore, the force acting on the pin can be calculated more accurately, and the breakage of the pin can be predicted more accurately. If the load applied to the flange portion is a distributed load that spreads over a wide range, it becomes difficult to construct a model, and the boundary conditions cannot be accurately determined.

In one embodiment,
A recording device is provided that is fixed to the annular portion and records a signal from the load sensor.

  According to the above-described embodiment, it is possible to extract a signal with a simple configuration as compared with signal extraction using a slip ring or a telemeter, and it is possible to reduce cost. Further, the influence of noise can be reduced, and the risk of disconnection can be significantly reduced.

Moreover, the load measuring method of the pin type cage of the present invention is:
Preparing a load detection pin having a load sensor on a shaft portion having an annular flange portion at one end and a fixed portion at the other end;
Fixing the load detecting pin fixing portion to the annular portion of the pin type retainer, and disposing the flange portion in the pin insertion hole of the roller; and
Determining the boundary condition of the load distribution model received by the pin of the pin type cage based on the output of the load sensor representing the load received by the flange portion from the inner peripheral surface of the pin insertion hole. Yes.

  According to the present invention, the portion in contact with the roller is the edge of the annular flange portion, so that contact close to point contact can be realized between the roller and the flange portion, and a point load (concentrated load) is applied to the flange portion. ) Can be applied. Therefore, the pin strain distribution model can be simplified and the boundary condition in the model can be determined more accurately. Therefore, the force acting on the pin can be calculated more accurately, and the breakage of the pin can be predicted more accurately. If the load applied to the flange portion is a load that spreads over a wide range, it becomes difficult to construct a model, and the boundary condition cannot be determined accurately.

In one embodiment,
The load distribution model is constructed with parameters including the friction coefficient between the pin and the roller, the friction coefficient of the sliding contact portion between the roller and the inner ring flange, and the friction coefficient of the rolling friction portion between the roller and the raceway. And
The step of determining the boundary condition is performed by determining parameters including the three friction coefficients so as to match the actual measurement.

  According to the embodiment, the analysis condition can be set more appropriately, and the life verification of the cage can be performed more accurately.

  ADVANTAGE OF THE INVENTION According to this invention, the force which acts on the pin of a pin type holder | retainer can be calculated more correctly, and the load measuring device and measuring method of a pin type holder | retainer which can predict the damage of a pin more correctly are realizable.

It is a figure showing a load measuring device of one embodiment of the present invention. It is sectional drawing of the axial direction which passes along the axial center of the tapered roller to which the load measuring device is not attached. It is a schematic diagram when the end surface is viewed from the axially outer side of the axial end surface of the small-diameter annular portion in the circumferential phase where the second pin exists before the strain data logger is attached. It is AA sectional view taken on the line of FIG. It is BB sectional drawing of FIG. It is a figure when the real machine shown in FIG.1 and FIG.2 is seen from the axial direction outward side of the small diameter annular part of the real machine. It is a measurement system | strain diagram of the load measuring apparatus of this embodiment.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a view showing a load measuring device for a pin type cage according to an embodiment of the present invention, including a sectional view in the axial direction of one tapered roller 32 to which the load measuring device is attached. .

  This load measuring device is attached to one tapered roller 32 among a plurality of hollow tapered rollers 32 disposed between the outer ring 30 and the inner ring 31. As shown in FIG. 1, the load measuring apparatus includes a large-diameter annular portion 1, a small-diameter annular portion 2, a first pin 3 as a load detection pin, a second pin 4 as a load detection pin, and a load sensor. A first strain gauge 5 and a second strain gauge 6 as an example, and a strain data logger 7 as an example of a recording apparatus.

  The large-diameter annular portion 1 is located on the large-diameter end face side of the tapered roller 32, while the small-diameter annular portion 2 is located on the small-diameter end face side of the tapered roller 32. The large-diameter annular portion 1 has a plurality of through holes, and the plurality of through-holes are arranged at intervals in the circumferential direction of the large-diameter annular portion 1. The small-diameter annular portion 2 also has a plurality of through-holes, and the plurality of through-holes are arranged at intervals in the circumferential direction of the small-diameter annular portion 2.

  The first pin 3 has a fixed portion 40, a shaft portion 41, and a flange portion 42. The fixing part 40 has a disk shape, and the diameter of the fixing part 40 is larger than the inner diameter of the through hole of the large-diameter annular part 1. The fixing portion 40 is disposed so as to block the opening on the opposite side of the small-diameter annular portion 2 side of one of the plurality of through-holes of the large-diameter annular portion 1. The shaft portion 41 has a large-diameter cylindrical portion 50 and a small-diameter cylindrical portion 51, and the large-diameter cylindrical portion 50 protrudes from the end surface of the fixed portion 40 on the large-diameter annular portion 1 side to the small-diameter annular portion 2 side. Yes. The large diameter cylindrical portion 50 is fitted in the one through hole.

  The outer diameter of the small diameter cylindrical portion 51 is smaller than the outer diameter of the large diameter cylindrical portion 50. The small diameter cylindrical portion 51 protrudes from the end surface of the large diameter cylindrical portion 50 opposite to the fixed portion 40 side to the small diameter annular portion 2 side. The flange portion 42 has an annular shape. The flange portion 42 extends in the radial direction from the end of the small diameter cylindrical portion 51 on the small diameter annular portion 2 side. Both the end portion of the small-diameter cylindrical portion 51 and the flange portion 42 are located closer to the large-diameter annular portion 1 than the center in the extending direction in the through hole 55 of the tapered roller 32.

  The flange portion 42 serves as a probe. The first pin 3 receives a load when the flange portion 42 contacts the inner peripheral surface of the through hole 55 of the tapered roller 32. And based on this load, the distortion which generate | occur | produces in the 1st pin 3 is calculated.

  On the other hand, the second pin 4 is arranged so as to close the opening on the opposite side of the large-diameter annular portion 1 of one of the plurality of through-holes of the small-diameter annular portion 2. The second pin 4 and the first pin 3 are opposed to each other in the axial direction of the tapered roller 32 disposed between the inner and outer rings 30 and 31. As shown in FIG. 1, the second pin 4 is different from the first pin 3 only in the shape of the fixing portion 60. The second pin 4 has an axially outer end surface 61 facing the axial direction of the inner ring 31. The normal direction of the end surface 61 in the axial direction of the second pin 4 substantially coincides with the axial direction of the inner ring 31. Other configurations of the second pin 4 are the same as those of the first pin 3.

  The first strain gauge 5 is attached to the small diameter cylindrical portion 51 of the first pin 3 with an adhesive or the like. The first strain gauge 5 has a known configuration, and a metal resistor (metal foil) laid out in a zigzag shape is attached to a thin insulator. The first strain gauge 5 is converted into a strain amount by measuring a change in electrical resistance due to deformation. When the small diameter cylindrical portion 51 of the first pin 3 is deformed, the first strain gauge 5 is also deformed at the same rate. The first strain gauge 5 has a thin metal resistor. The thin metal resistor has a reduced cross-sectional area and an increased length due to elongation, and as a result, the resistance value increases. The first strain gauge 5 uses this resistance change for measurement. This resistance change is minute and the detection is performed using a bridge circuit called a so-called strain amplifier and a voltage amplifier. The second strain gauge 6 is attached to the small diameter cylindrical portion of the second pin 4 with an adhesive or the like. The second strain gauge 6 is the same as the first strain gauge 5. The strain data logger 7 receives signals from the first and second strain gauges 5 and 6 through lead wires existing in the first and second strain gauges 5 and 6, respectively, and records strain information. It is supposed to be.

  FIG. 2 is a sectional view in the axial direction passing through the axial center of the tapered roller 32 to which no load measuring device is attached.

  As shown in FIG. 2, the through hole of the large-diameter annular portion 1 is a screw hole at a location where the first strain gauge 5 (first pin 3) does not exist in the circumferential direction. The small-diameter annular portion 2 is coupled by an integral pin (a pin used in a pin type retainer) 70. The screw hole of the large-diameter annular portion 1 and one end portion of the pin 70 are fixed by screwing. On the other hand, the small-diameter annular portion 2 and the other end portion of the pin 70 are fixed by a flanged nut 71. Specifically, after an annular press-fit bush 72 is fitted on the outer peripheral surface of the other end of the pin 70, a flange-attached nut 71 is screwed from the axially outer side of the press-fit bush 72, and further provided with a flange. The flange surface of the nut 71 is pressed against the step portion present in the through hole of the small diameter annular portion 2. In this way, the pin 70, the press-fit bush 72, the inner peripheral surface of the through hole of the small-diameter annular portion 2, and the flanged nut 71 cannot be moved relative to each other, and the other end of the pin 70 is the small-diameter annular portion. The relative movement with respect to 2 is impossible.

  In a normal pin type cage, the annular portion warps or bends due to the heat effect of welding, and this annular portion warps or bends. C. The roundness of D is changed, or the axial clearance between the cage and the roller is changed. As a result, the behavior of the roller changes, and the impact force between the roller and the cage may be affected. In this embodiment, the small-diameter annular portion 2 side is fixed by the flanged nut 71, and welding is not used. Therefore, the life measurement can be performed without the influence of welding, and the pin life is more accurate. Can be verified.

  FIG. 3 shows the end surface viewed from the axially outer side of the axial end surface of the small-diameter annular portion 2 in the circumferential phase where the second pin 4 exists before the strain data logger 7 is attached. FIG.

  As shown in FIG. 3, the fixing portion 60 of the second pin 4 has a press-fitting guide hole 80 and a lead wire drawing hole 81, and the small-diameter annular portion 2 has a drawing tap hole 82. Since the attached portions of the strain gauges 5 and 6 cannot be visually confirmed, there is no need to take any measures when the first and second pins 3 and 4 for measurement are pressed into the annular portions 1 and 2. The measurement direction of the strains 5 and 6 does not coincide with the direction in which the strain on the cylindrical portion is desired to be measured.

  In the present embodiment, the press-fit guide hole 80 is provided in the fixing portion 60 of the second pin 4 and the pull-out tap hole 82 is provided in the side surface of the small-diameter annular portion 2, so that the second pin 4 is guided by the cap bolt. The second pin 4 can be prevented from being displaced in the circumferential direction.

  4 is a cross-sectional view taken along line AA in FIG. 3, and FIG. 5 is a cross-sectional view taken along line BB in FIG. As shown in FIGS. 4 and 5, the second strain gauge 6 is arranged so that the strain measurement direction is substantially parallel to the radial direction of the tapered roller bearing. In this manner, the second strain gauge 6 can accurately and efficiently detect the strain in the load acting direction indicated by the arrow A in FIG. 5 which is perpendicular to the radial direction.

  FIG. 6 is a view of the actual machine shown in FIGS. 1 and 2 when viewed from the outside in the axial direction of the small-diameter annular portion of the actual machine. In FIG. 6, the outer ring 30 and the inner ring 31 are not shown.

  As shown in FIG. 6, a distortion data logger 7, a vibration data logger 88, and a data logger battery 89 are fixed to the small-diameter annular portion 2. The vibration data logger 88 is provided for measuring the vibration acceleration of the cage, and thereby, the contribution of the cage vibration to the acting force exerted on the pin can be investigated. The data logger battery 89 is provided to supply power to the distortion data logger 7 and the vibration data logger 88. In FIG. 6, reference numeral 102 indicates a triaxial vibration acceleration pickup.

  FIG. 7 is a measurement system diagram of this embodiment.

  As shown in FIG. 7, in the load measuring apparatus, in the strain measurement, signals from the first and second strain gauges 5 and 6 are stored in the strain data logger 7 via lead wires. When the information stored in the distortion data logger 7 is analyzed, the information stored in the distortion data logger 7 is extracted to the communication adapter 100 via the communication cable, and the information is further transferred to the USB cable. Through the PC 101 for analysis.

  In the load measuring apparatus of this embodiment, the vibration acceleration measurement is such that the signal from the triaxial vibration acceleration pickup 102 is stored in the vibration data logger 88 via the low noise cable. Then, when analyzing the information stored in the vibration data logger 88, the information stored in the vibration data logger 88 is taken out to the communication adapter 103 via the communication cable, and the information is further transferred to the USB cable. Through the PC 101 for analysis. Measurement of the positions of the strain gauges 5 and 6 and the triaxial vibration acceleration pickup 102 is performed by the laser pointer 105 by a well-known method described in JP 2011-149538 A or the like. The positions of the strain gauges 5 and 6 and the triaxial vibration acceleration pickup 102 can be collated with strain and vibration.

  In this load measuring device, the end portions on the radially outer side of the disk-like flange portions 42 of the first and second pins 3 and 4 are close to point contact with the inner peripheral surface of the through hole of the tapered roller 32. By making the contact, the load applied locally to the first and second pins 3 and 4 is accurately measured. Then, the boundary condition of the model is obtained at the first and second pins 3 and 4 of the two cantilever structures so that the actually measured value matches the load at the local location predicted by the model. It is like that.

  In order not to contradict this boundary condition, the load acting on the integrated pin is generalized by a plurality of parameters including the boundary condition. This generalization can be performed by mechanism analysis software. Finally, a test is actually performed using an integrated pin, and the stress at the failure starting point is obtained by FEM (Finite Element Method) analysis, so that there is no contradiction between the model and the actual measurement. It is to confirm whether or not. That is, in this embodiment, a beam element model is adopted so that the output of the acting force on the target pin can be calculated. In this analysis, the pin part model in the dynamic analysis is a rigid body.

  The following is a brief description of each step in which the measurement value and the analysis value are combined in the present embodiment.

  (1) First, in the tapered roller bearing, the pin is divided into two actually measured pins (two cantilever-structured pins) at one location in the circumferential direction, and the strain at the location where the strain gauge is applied is measured. The parameters of the model are determined so as to match the calculated distortion at the corresponding location in the model with the actually measured distortion.

  (2) Here, when the calculation distortion of the model does not match the measured value, the revolution speed of the cage is adjusted. This adjustment includes the friction coefficient of the contact part with the pin, the friction coefficient of the sliding contact part between the roller and the inner ring, and the friction coefficient in the rolling friction between the roller and the raceway among the parameters existing in the model. Tune and do.

  (3) Once the strain alignment in the two cantilever structures is completed, the boundary conditions determined in the previous steps in the actual machine structure (usually one pin, fixed beam at both ends) Check if is applicable. Specifically, the boundary conditions determined by combining the strains in the two cantilever beam structures are applied to the mechanism analysis model for all normal pins, and the acting force at the pin (maximum impact force) and each Calculate the frequency of action force. Note that no distortion is used from this step. The calculation conditions at this time are the operating conditions (rotation speed, acceleration / deceleration of the rotation speed, bearing load) in the case of damage that has occurred in the past in the reproduction durability test on an actual machine or bench. On the other hand, an SN diagram (hereinafter, this diagram is referred to as the diagram (A)) of the acting force and the number of breakage of the pin is prepared in advance in another test. Here, as the acting force, the stress at the break starting point is calculated by FEM analysis, and compared with the fatigue level of the pin, the validity of the diagram is confirmed. As a result, a generalized SN diagram (database) in which the vertical axis represents stress and the horizontal axis represents the number of repetitions until breakage can be prepared separately (for example, Japanese Patent Application Laid-Open No. 2004-286066). And, from the acting force and occurrence frequency obtained by mechanism analysis, based on the diagram of (A) above, using the minor rule, obtain the time to breakage, and if it matches the time in the actual machine or test machine, Judge that the calculation conditions are appropriate.

  (4) If the calculated value is appropriate, the analysis condition setting of the dynamic analysis calculation model is determined, and the actual design is performed. Then, the strength and life of the cage are calculated based on this analysis condition setting. Incidentally, a tapered roller bearing for a wind power generator usually requires a calculation life verification of 20 to 25 years. According to the method of the present embodiment, it is possible to verify the life of the cage in addition to the fatigue life verification of the bearing ring currently performed.

  According to the load measuring device and method of the above-described embodiment, a model incorporating an actual measurement step, which did not exist conventionally, can be constructed. Therefore, predictions such as breakage of a pin of a large-sized bearing such as a bearing that supports the main shaft of a wind power generator or the like can be performed much more accurately than before.

  In addition, according to the load measuring device and method of the above embodiment, the portion that contacts the tapered roller 32 is the edge of the annular flange portion 42, so that the tapered roller 32 and the flange portion 42 are in point contact. Close contact can be realized, and a load close to a point load (concentrated load) can be applied to the flange portion 42. Therefore, the model of pin strain distribution can be greatly simplified, and boundary conditions in the model can be determined more accurately. Therefore, the force acting on the pin can be calculated more accurately, and the breakage of the pin can be predicted more accurately. If the load applied to the flange portion is a distributed load that spreads over a wide range, it becomes difficult to construct a model, and the boundary conditions cannot be accurately determined.

  Moreover, according to the load measuring apparatus and method of the said embodiment, compared with the signal extraction which uses a slip ring and a telemeter, while being able to extract a signal with a simple structure, cost can be reduced. . Further, the influence of noise can be reduced, and the risk of disconnection can be significantly reduced.

  In the above embodiment, the three-axis vibration acceleration pickup 102 is provided and vibration measurement is possible. However, in the present invention, there is no vibration measurement device, and vibration measurement may not be performed.

  Further, in the above embodiment, in order to perform measurement and alignment with the model, the friction coefficient of the contact portion with the pin, the friction coefficient of the sliding contact portion between the roller and the inner ring cage, and the roller and the raceway Although the tuning is performed using the friction coefficient in rolling friction as a parameter, in this invention, the rotation speed of the roller may be added as a parameter to these parameters, and the model and actual measurement may be tuned. Further, when there is a load difference between the two cantilever pins and the influence of the skew of the rollers seems to be large, the behavior of the rollers (skew) may be adjusted. Further, the rigidity of the measuring pin may be adjusted within the range of common sense. Needless to say, parameters other than those described above may be used as parameters for matching the actual measurement with the model.

  In the above-described embodiment, the two-divided pins for measurement (first and second pins 3, 4) are arranged at one place in the circumferential phase of the measuring instrument. In the present invention, the two-divided pins for measurement are used. The (first and second pins) may be arranged at a plurality of locations in the circumferential phase of the measuring instrument.

  Any known software may be used as the mechanism analysis software for calculating the strain distribution.

  Further, in the above embodiment, the measurement was the strain distribution of the pins that contact the inner peripheral surface of the hollow tapered roller 32. In the present invention, however, the inner peripheral surface of the hollow cylindrical roller is measured. It may be a strain distribution of a pin that comes into contact with the pin, or may be a strain distribution of a pin that comes into contact with the inner peripheral surface of a hollow convex roller.

DESCRIPTION OF SYMBOLS 1,2 Annular part 3 1st pin 4 2nd pin 5 1st strain gauge 6 2nd strain gauge 7 Strain data logger 32 Tapered roller 40,60 Fixed part 41 Shaft part 42 Flange part 55 Pin insertion hole

Claims (4)

A fixed portion fixed to an annular portion having a through hole;
A shaft portion that can extend from the fixed portion into the pin insertion hole of the roller;
An annular flange portion extending from the outer peripheral surface of the shaft portion to the outer side in the radial direction of the shaft portion and positioned in the inner peripheral surface of the pin insertion hole and capable of contacting the inner peripheral surface; ,
A load measuring device for a pin type cage, comprising a load sensor fixed to the outer peripheral surface of the shaft portion. In the load measuring device according to claim 1,
A load measuring device for a pin type retainer, comprising a recording device fixed to the annular portion and recording a signal from the load sensor. Preparing a load detection pin having a load sensor on a shaft portion having an annular flange portion at one end and a fixed portion at the other end;
Fixing the load detecting pin fixing portion to the annular portion of the pin type retainer, and disposing the flange portion in the pin insertion hole of the roller; and
Determining the boundary condition of the load distribution model received by the pins of the pin type cage based on the output of the load sensor representing the load received by the flange portion from the inner peripheral surface of the pin insertion hole. To measure the load of the pin type cage. In the load measuring method of the pin type cage according to claim 3,
The load distribution model is constructed with parameters including the friction coefficient between the pin and the roller, the friction coefficient of the sliding contact portion between the roller and the inner ring flange, and the friction coefficient of the rolling friction portion between the roller and the raceway. And
The step of determining the boundary condition is performed by determining a parameter including the three friction coefficients so as to match the actual measurement.

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