JPH085517A - Measurement of engaging transmission error of gear - Google Patents

Abstract

PURPOSE:To accurately measure the engaging transmission error of gear by eliminating the effect of a measuring device. CONSTITUTION:The measuring method is used to measure the engaging transmission error between a driving gear and driven gear on the basis of the values outputting from a first detector for detecting the rotating condition of the driving gear and a second detector for detecting the rotation of the driven gear, while the driving gear is rotated by a rotary driving means and the driven gear engaged therewith is rotated. A testing gear 14 in which a projection 16 having an already-known height is formed in the central part of a simultaneous contact line on a tooth face is used as a driving gear or driven gear and the engaging transmission error is actually measured. At the same time, a ratio of the actually measured value of engaging transmission error to the height of projection is obtained and the measurement result of the engaging transmission error of the testing driving gear and driven gear is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring gear transmission error in a differential gear device or the like.

[0002]

2. Description of the Related Art In a gear transmission, the teeth of a driving gear and the teeth of a driven gear mesh with each other to transmit torque, and the meshing of a pair of teeth and their disengagement occur repeatedly. It becomes a cause of noise. The noise generated in the gear transmission tends to increase as the mesh transmission error increases. Therefore, in order to reduce the noise, it is necessary to grasp the transmission error in the gear transmission as a premise.

Here, the transmission error is a slight advance or delay of the rotation of the output shaft with respect to the rotation of the input shaft, and an example of a measuring device thereof is described in Japanese Patent Laid-Open No. 1-305334. The device described in this publication is a device for measuring a transmission error for a differential gear.
From the output shaft and the pulse train accompanying each rotation,
Along with forming an asynchronous addition pulse train of a pulse train for the output shaft, dividing the pulse train for the input shaft and the asynchronous addition pulse train at a predetermined ratio, and measuring the transmission error by obtaining the phase difference of the divided output. It is configured.
Therefore, according to the above-mentioned conventional measuring device, since the transmission error can be measured in a state where the two output shafts are both rotated, it is more accurate than the device that measures one output shaft. The transmission error can be measured.

[0004]

By the way, the transmission error in the gear transmission is basically measured by applying a driving force to the input shaft by a motor or the like and at the same time applying an appropriate load to the output shaft. Is performed by calculating the rotational phase difference between the input shaft and the output shaft. Therefore, the measurement system includes various devices such as a motor, a rotary encoder, and a shaft coupling, and the members and means for connecting them are not completely rigid bodies, so that a torsional vibration system is formed as a whole. It will be. Therefore, the rotational phase difference between the input shaft and the output shaft appears in a state where the phase difference due to the transmission error of the gear and the phase difference due to the torsional vibration are superposed, and there is a resonance point at a predetermined frequency.

FIG. 8 shows this state, and the amplitude ratio on the vertical axis is the ratio between the amplitude ratio of the measured rotational phase difference and the amplitude of the true transmission error. Therefore, the influence of resonance is eliminated as much as possible by measuring the transmission error in the stable region where the amplitude ratio is close to "1". However, the value obtained in this way does not represent a true meshing transmission error because it includes the vibration of the torsional vibration system even if the error due to resonance is small.

As described above, in the related art, since the rotational phase difference of the input / output shaft affected by the torsional vibration characteristic of the measuring device as a whole cannot be obtained, the true transmission error of the gear transmission (mesh transmission). However, there is a disadvantage that the absolute value of the error) cannot be known, and thus an accurate measure for improving the gear transmission or reducing noise cannot be taken.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method capable of accurately measuring the meshing transmission error of gears and being easily implemented. is there.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention takes into consideration the torsional vibration characteristics of the measuring means to determine the true value of the gear transmission error. It is a feature. Specifically, in the invention described in claim 1, the rotation driving means rotates the drive gear and also rotates the driven gear meshed with the drive gear to detect the rotational state of the drive gear and the first detector. In the gear transmission error measuring method for measuring the gear transmission error between the drive gear and the driven gear based on the output value from the second detector that detects the rotation of the gear, a protrusion of known height is formed on the tooth surface. A test gear formed in the center of the simultaneous contact line is used as the drive gear or the driven gear to measure the meshing transmission error, and the ratio between the measured value of the meshing transmission error due to the protrusion and the height of the protrusion is obtained. In the method, the measurement result of the meshing transmission error of the test drive gear and the driven gear is corrected by the ratio.

According to a second aspect of the present invention, the drive gear is rotated by the rotation drive means and the driven gear meshed with the drive gear is rotated to detect the rotational state of the drive gear and the driven gear. Second to detect the rotation of
In the gear transmission error measuring method for measuring the gear transmission error between the drive gear and the driven gear based on the output value from the detector, at least the first detection is performed by applying a predetermined input to the drive gear. Vibration characteristic value in the power transmission path from the detector to the second detector, and the mesh transmission error between the drive gear and the driven gear is calculated based on the torsion vibration characteristic value and the output value of each detector. It is a method characterized by that.

[0010]

In the method according to the first aspect, the drive gear of the test gear is forcibly rotated, and the driven gear meshed with the drive gear is also rotated. In that case, the driven gear may be loaded as necessary. Then, the rotation of the drive gear is detected by the first detector, and the rotation of the driven gear is detected by the second detector. Basically, the mesh transmission error between these drive gear and the driven gear is It is calculated as the delay / advance of the rotation of the driven gear with respect to the rotation. On the other hand, in place of the driving gear or the driven gear, a test gear is used to measure the meshing error. Since the tooth surface of this test gear is provided with a protrusion having a known height, a large meshing transmission error occurs corresponding to the protrusion. Since the meshing transmission error is caused by the protrusion having a known height, the ratio between the actually measured value and the height of the protrusion is the torsional vibration of the measuring means including the transmission member between each detector or each gear. The characteristic, that is, the rotation angle represents the transmission amplification factor. By correcting the measurement result of the meshing transmission error between the driving gear and the driven gear by this ratio, the true value excluding the influence of the measuring means can be obtained. .

According to the second aspect of the present invention, the drive gear and the driven gear are meshed with each other and a rotational driving force is applied to the drive gear to rotate these gears. The meshing transmission error is calculated as the delay or advance of the relative rotation of the gears. Further, in the invention of claim 2, the input value of which parameters such as frequency and torque are known is applied to the drive gear to obtain the torsional vibration characteristic value of the power transmission system between the first detector and the second detector. Then, the mesh transmission error is calculated based on the torsional vibration characteristic value and the measured value of the delay / advance of the rotation of the driven gear with respect to the rotation of the drive gear, and as a result, the true value of the mesh transmission error without the influence of the measuring means. Can be asked.

[0012]

EXAMPLES The present invention will now be described based on examples. First, the basic configuration of the meshing transmission error measuring device will be described. FIG. 1 is a block diagram of a device for a differential gear mechanism (differential gear unit). A motor 1 which is a rotation driving means is connected to an input shaft of a gear box 2 for accelerating and decelerating, and a torque meter 4 is connected to an output shaft of the gear box 2 via a transmission unit 3 such as a constant velocity joint. ing. Further, a rotary encoder 6 which is a rotation detector is connected to the torque meter 4 via a shaft coupling (Ω coupling) 5,
The drive gear 8 in the differential gear mechanism 7 is connected to the rotary encoder 6.

On the other hand, the driven gears (side gears) 9, 9 meshing with the drive gear 8 are rotary encoders 10, 10 which are detectors for detecting the rotation and outputting signals.
Are connected. In order to apply a load to the driven gears 9, 9, the rotary encoders 10, 10 are connected to the shaft couplings (Ω couplings) 11, 11 and the gear boxes 12, 12 and the motors 13, 13 subsequently.

Assuming that the differential gear mechanism 7, which is the test gear, has no tooth profile error, elastic deformation, or pitch error, the drive gear 8 rotates when the drive gear 8 is rotated by the motor 1. Although there is no difference between the angle and the rotation angle of the driven gears 9 and 9, in reality, there is a meshing transmission error between the drive gear 8 and the driven gears 9 and 9 due to a tooth profile error and elastic deformation. Occurs. Specifically, there is a difference between the rotation angle of the drive gear 8 obtained based on the output signal of the rotary encoder 6 and the rotation angle of one driven gear 9 obtained based on the output signal of the rotary encoder 10.

FIG. 2 shows a result of measuring a difference in rotational angle between a driving gear and a driven gear in a differential gear mechanism including a hypoid gear as an engagement transmission error. The reason why the measurement result shows a wavy shape that is convexly curved in FIG. 2 is that the tooth profile error and elastic deformation of the tooth occur, and the overall upward slope is shown in the figure. This is because the range is a portion where the pitch error is cumulatively large. Further, when no load is applied, each tooth meshes independently (with only one tooth) in the range (1 pitch) shown by the solid line, and when a load is applied, two teeth mesh at the same time in the range shown by the broken line. And the transmission error e of each tooth
Is represented by the amount of separation of the convex curve from the straight line L.

The mesh transmission error e obtained based on the output signals of the rotary encoders 6 and 10 is the rotary encoders 6 and 10 by the measuring device shown in FIG.
Since it was obtained by directly using the output value of, the amount of elastic deformation (vibration) peculiar to the measuring device shown in FIG. 1 is included. That is, the rotary encoder 6,
10 does not directly detect the rotation angles of the gears 8 and 9, but means for transmitting torque is provided between them, so that the torque transmitting means and the rotary encoders 6 and 10 are provided. The amount of elastic deformation is added. In order to remove this and obtain a true value, the following correction is performed.

FIG. 3 shows a predetermined tooth 15 of the test gear 14 for this purpose. This test gear 1
Reference numeral 4 is a hypoid gear similar to the test gear, and a protrusion 16 having a known height H is formed in the center of the tooth surface of a predetermined tooth 15 of the hypoid gear. That is, the tooth surface is a surface that transmits the torque by coming into contact with the teeth of the mating gear, and the meshing progresses in the direction indicated by the arrow. And the protrusion 16 is
It is formed in a thin strip shape, and is formed so as to be inclined in a direction (simultaneous contact line direction) substantially orthogonal to the meshing advancing direction. The width of the projection 16 is set so that the engagement between the projection 16 and the teeth of the other party starts and ends when only the teeth 15 forming the projection 16 engage with the teeth of the other party. There is.

The test transmission gear 14 is used to measure the meshing transmission error, and the resulting meshing transmission error curve is shown in FIG. As shown in FIG. 4, when the protrusion 16 meshes with the mating tooth, the rotation angle of the gear on the driven side becomes large. Therefore, the meshing transmission error actually measured as the rotation angle difference depends on the shape of the protrusion 16. Grows accordingly. That is, the waveform temporarily changes greatly. The amount of change D is the amount of change corresponding to the protrusion 16 under conditions such as the input measured using the test gear 14, and the ratio between the height H of the protrusion 16 and the amount of change D ( H
/ D = α) is a characteristic value (amplification factor) due to elastic deformation of the measuring device under the conditions. Therefore, in the present invention, the true value of the meshing transmission error is identified by correcting the measured value of the meshing transmission error of the test gear, that is, the value shown in FIG. 2 by the ratio α. For example, the measured value is multiplied by the correction value α. An example of the waveform of the meshing transmission error corrected in this way is shown by a chain line in FIG. The meshing transmission error thus obtained does not include factors such as elastic deformation of the measuring means, and therefore accurately represents the meshing transmission error of the gears 8 and 9.

In the method of obtaining the correction value α using the test gear 14 and correcting the actual measurement value with the correction value α, it is necessary to perform the actual measurement and the test under substantially the same conditions.
In addition, it is necessary to have a low torque that does not crush the protrusions 16 and a low rotational speed that does not disengage the teeth due to the acceleration caused by the protrusions 16 (the tooth surfaces are not separated). Therefore, the following method is advantageous as a more general method.

As described above, the measuring device shown in FIG.
Inevitable elastic deformation occurs, and torsional vibration resulting therefrom is a factor that makes it impossible to obtain the true value of the meshing transmission error. Therefore, the torsional vibration characteristics of the measuring device shown in FIG. 1 are analyzed as follows.

FIG. 5 is a torsional vibration model of the measuring apparatus shown in FIG. 1, in which the driving motor 1 to one driven gear 9 are used.
Shows a vibration model of a power transmission path as a load to the motor 13 through I, I is an inertia moment of an inertial body such as a motor or a gear, k is a spring constant of a transmission path between the inertial bodies, and c is Similarly, the damping coefficient, θ is the rotation angle of each inertial body, and e is the meshing transmission error between the drive gear 8 and the driven gear 9 which are the test gears. The equation of motion in this vibration model is expressed by the following equation 1.

[0022]

[Equation 1] In Equation 1, one dot indicates the first derivative, and two dots indicate the second derivative.

By the way, the amplitude of the meshing transmission error e is E, the vibration amplitude of the rotation angle of each inertial body is λ _n , and the phase difference is φ.
Assuming that _{n is n} , the angular velocity is ω, and the time is t, the meshing transmission error e and the rotation angle θ of each inertial body are expressed by Equation 2.

[0024]

[Equation 2] Solving Equation 1 using this, the amplitude E of the meshing transmission error
Becomes like Equation 3.

[0025]

(Equation 3) Here, each of Q, B, and M is represented by the amplitude ratio of the vibration when E = 0, and q, b, and m are each E
The phase difference when = 0 is expressed as follows.

Q = λ4 / λ3 B = λ3 / λ2 M = λ4 / λ5 q = φ4−φ3 b = φ3−φ2 m = φ4−φ5 Since the damping at the tooth surface of the gear is negligible, It is possible to set C ₃ = 0, and finally E becomes as shown in Equation 4.

[0027]

[Equation 4] That is, the measured values λ ₂ , λ ₅ , and (φ ₂ −φ ₅ ) of the rotation angle and phase difference of the drive gear 8 and the driven gear 9 are corrected by the characteristic values of the measuring device to obtain the true meshing transmission error E. Become. The characteristic values Q, B, M, q, b, m can be obtained as follows, for example.

6 (a) and 6 (b) show an example of a vibration experiment for obtaining the above-mentioned characteristic values of the measuring apparatus shown in FIG. In the vibration experiment, the weight 17 is attached to the output side of the gear box 2, and the shaker 18 that applies known vibrations of torque and frequency is connected to the output side of the torque meter 4. Rotational vibration is applied by the vibrator 18 to detect the rotational state of the drive gear 8 such as angular velocity and angular acceleration by using the acceleration sensor 19, and at the same time, the angular velocity and angular acceleration of the rotary encoder 10 on the driven gear 9 side are detected. The rotation state is detected using the acceleration sensor 20. Further, in the vibration experiment shown in FIG. 6B, the vibrator 18 gives rotational vibration to the driven gear 9, and the acceleration sensor 19 detects the rotational state such as the angular velocity and the angular acceleration of the drive gear 8. The acceleration sensor 21 indicates the rotational state of the rotary encoder 6 on the drive gear 8 side, such as angular velocity and angular acceleration.
Detect with.

Therefore, the rotation angle λ ₂ and the phase φ _{2 of the} rotary encoder 10 and the rotation angle λ ₄ and the phase φ _{4 of} the drive gear 8 are obtained from the vibration experiment shown in FIG. Then, λ ₄ / λ ₂ = Q · B φ ₄ −φ ₂ = q + b is obtained. Further, from the vibration experiment of FIG. 6B, the rotation angle λ ₅ and the phase φ _{5 of the} rotary encoder 6 and the rotation angle λ ₄ and the phase φ _{4 of} the drive gear 8 are obtained, and based on these, λ ₄ / λ ₅ = M φ ₄ −φ ₅ = m is obtained. Note that these characteristic values are different based on the frequency of the input forced vibration. Therefore, when calculating the meshing transmission error, the value at the same frequency as the frequency in the measurement test described below is adopted. It will be.

The measurement of the mesh transmission error of the test gear can be carried out by the measuring device shown in FIG.
In order to measure the rotational fluctuations of the driving gear 8 and the driven gear 9 more accurately, it is preferable to use the measuring device shown in the block diagram of FIG. The characteristic configuration here is that a high-precision oscillator 22 that outputs a reference pulse signal having a constant frequency is used, and the pulse signal output from the rotary encoder 6 on the drive gear 8 side is a high-precision oscillator. The reference pulse output from 22 is compared with the phase difference meter 23, and the pulse signal output from the rotary encoder 10 on the driven gear 9 side is compared with the reference pulse output from the high precision transmitter 22 with the phase difference meter 24. It is supposed to be done. The output signals from the phase difference meters 23 and 24 are input to the frequency analyzer (fast Fourier transformer) 25 to drive the drive gear 8
The rotational angle and the phase between the driven gear 9 and the driven gear 9 can be obtained. Therefore, according to the device shown in FIG. 7, the rotation angles and phases of the gears 8 and 9 are detected based on the comparison with the reference pulse which is always stable. The measured value is accurately detected even if it includes the torsional vibration of the measuring device.

In this way, all the parameters in the equation 4 can be known, and by substituting the values into the equation 4, the true value of the meshing transmission error E can be obtained. As is clear from the above description, the value is corrected so as not to include the error caused by the torsional vibration of the measuring device, and therefore the meshing transmission error of the gears 8 and 9 can be known. . Further, in the above-described vibration experiment, there is no particular limitation on the size or frequency of the tokule input from the vibration exciter 18, so the applicable range of the above-described method is wide.

The present invention is not limited to the above-mentioned embodiment, and for example, means for obtaining the characteristic value of the measuring device,
The method is not limited to the above two vibration experiments, and other means / methods can be adopted as necessary,
For example, the connecting position of the vibration exciter may be constant, and the sensor for detecting the rotation state is not limited to the acceleration sensor, but may be an appropriate displacement sensor. Further, the method of the present invention is not limited to the case of measuring the mesh transmission error of the differential gear, but can be widely applied to the case of measuring the mesh transmission error of general gears. When forming the above-mentioned protrusion on a predetermined tooth, it is not limited to forming the protrusion on only one tooth, and the protrusion may be formed on a plurality of teeth. The configuration of the measuring device is not limited to the structure shown in FIG. 1, and the means for applying the rotational force and the means for applying the load may be something other than the motor, and the means for detecting the rotation are not limited to the rotary encoder.

[0033]

As described above, according to the invention described in claim 1, the gears under test are engaged with each other to rotate, and the relative delay / advancement of rotation of one of the gears at that time, that is, the mesh transmission error. When measuring, the increase rate of the meshing transmission error, that is, the correction value is obtained from the actual measurement result due to the engagement of the protrusions of known height, and the actual measurement value is corrected by the correction value. It is possible to obtain an accurate meshing transmission error that is not affected.

According to the second aspect of the invention, the calculation is performed based on the torsional vibration characteristic value due to the elasticity of the measuring device and the actual measurement value of the mesh transmission error of the test gear, and the true mesh transmission error is calculated. Since the value is obtained, the actually measured value of the meshing transmission error is corrected by the characteristic value of the measuring device, and thus the accurate meshing transmission error without the influence of the measuring device can be obtained.

[Brief description of drawings]

FIG. 1 is a system diagram of an example of a meshing transmission error measuring device used when implementing a method of the present invention.

FIG. 2 is a waveform diagram of an example in which relative delay / lead of each tooth is actually measured as a meshing transmission error.

FIG. 3 is a perspective view showing an example of the shape of teeth having protrusions.

FIG. 4 is a diagram showing an actually measured waveform of an engagement transmission error caused by the protrusion.

5 is a diagram showing a torsional vibration model of the measuring apparatus shown in FIG.

FIG. 6 is a schematic diagram for explaining a method of a vibration test for the device shown in FIG.

FIG. 7 is a block diagram for explaining an example of an apparatus for measuring the rotation state of a test gear.

FIG. 8 is a diagram showing a resonance phenomenon of a meshing transmission error caused by a torsional vibration of a measuring device.

[Explanation of symbols]

 1 Motor 6,10 Rotary Encoder 7 Differential Gear Mechanism 8 Drive Gear 9 Driven Gear 14 Test Gear 16 Protrusion 18 Vibrator 19, 20, 21 Accelerometer

Claims (2)

[Claims] 1. A first detector for detecting the rotation state of the drive gear and a second detection for detecting the rotation state of the drive gear by rotating the drive gear by the rotation drive means and rotating the driven gear meshing with the drive gear. In the gear transmission error measuring method for measuring the gear transmission error between the drive gear and the driven gear based on the output value with the gear, a protrusion having a known height is formed at the central portion of the tooth surface in the meshing advancing direction. A test gear is used as the drive gear or the driven gear to measure the meshing transmission error, and the ratio between the measured value of the meshing transmission error due to the protrusion and the height of the protrusion is obtained to determine the meshing of the test drive gear and the driven gear. A method for measuring transmission error of gears, characterized in that the measurement result of transmission error is corrected by the ratio. 2. A first detector for detecting the rotation state of the drive gear and a second detection for detecting the rotation state of the drive gear by rotating the drive gear by the rotation drive means and rotating the driven gear meshing with the drive gear. In the gear transmission error measuring method for measuring the gear transmission error between the drive gear and the driven gear based on the output value of the drive gear, at least the first detector is provided by applying a predetermined input to the drive gear. To obtain a torsional vibration characteristic value in the power transmission path from the second detector to the second detector, and calculate an engagement transmission error between the drive gear and the driven gear based on the torsional vibration characteristic value and the output value of each detector. A method for measuring transmission error of meshing gears.