JP3085093B2 - Gear transmission error measurement method - Google Patents

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 a transmission error of a gear in a differential gear device or the like.

[0002]

2. Description of the Related Art In a gear transmission, teeth of a driving gear and teeth of a driven gear mesh with each other to transmit torque, and the meshing and disengagement of a pair of teeth occur repeatedly. , Which is 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 precondition.

Here, the transmission error is a minute advance or delay of the rotation of the output shaft with respect to the rotation of the input shaft, and an example of the measuring device is described in JP-A-1-305334. The device described in this publication is a transmission error measuring device for a differential gear, and includes an input shaft and a transmission shaft.
From the two output shafts and the pulse train accompanying each rotation,
As well as forming an asynchronous addition pulse train of the pulse train for the output shaft, dividing the pulse train for the input shaft and the asynchronous addition pulse train by 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-described conventional measuring device, the transmission error can be measured while the two output shafts are rotated together, so that the measurement can be performed more accurately as compared with a device in which one output shaft is fixed and measured. Transmission errors can be measured.

[0004]

The measurement of the transmission error in the gear transmission is basically performed by applying a driving force to the input shaft by a motor or the like and simultaneously applying an appropriate load to the output shaft. To obtain the rotational phase difference between the input shaft and the output shaft. Therefore, various devices such as a motor, a rotary encoder, and a shaft coupling are interposed in the measurement system, and the members and means for connecting them are not completely rigid, so that a torsional vibration system is configured as a whole. Will be. Therefore, in the rotational phase difference between the input shaft and the output shaft, a phase difference caused by a transmission error of the gear and a phase difference caused by torsional vibration appear in a superimposed state, and there is a resonance point at a predetermined frequency.

FIG. 8 shows this state. The amplitude ratio on the vertical axis is the ratio between the measured amplitude ratio of the rotational phase difference and the amplitude of the true transmission error. Therefore, by measuring the transmission error in a stable region where the amplitude ratio is close to "1", the influence of resonance is eliminated as much as possible. 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 prior art, since only the rotational phase of the input / output shaft affected by the torsional vibration characteristics of the measuring device can be obtained, the true meshing transmission error (meshing transmission) of the gear transmission device can be obtained. (Absolute value of the error) cannot be known, and as a result, there has been a problem that an accurate measure for improving the gear transmission device or reducing the noise cannot be taken.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a method that can accurately measure a gear transmission error and that can be easily implemented. is there.

[0008]

According to the present invention, in order to achieve the above object, a true value of a meshing transmission error of a gear is determined in consideration of a torsional vibration characteristic of a measuring means. It is a feature. More specifically, the first aspect of the present invention includes a first detector that detects the rotational state of the drive gear by rotating the drive gear by rotating the drive gear and rotating a driven gear meshed with the drive gear. In the gear transmission error measuring method for measuring the transmission error between the drive gear and the driven gear based on the output value of the second detector that detects the rotation of the gear, a projection having a known height is provided on the tooth surface. A test gear formed at the center of the simultaneous contact line is used as the drive gear or the driven gear to measure the mesh transmission error and determine the ratio between the measured value of the mesh transmission error by the projection and the height of the projection, The method is characterized in that the measurement result of the mesh 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, there is provided a first detector and a driven gear for detecting the rotational state of the driving gear by rotating the driven gear by rotating driving means and rotating a driven gear meshed with the driving gear. Of rotation detection
In a gear transmission error measuring method for measuring a transmission error between the driving gear and the driven gear based on an output value from a detector, at least the first detection is performed by giving a predetermined input to the driving gear. The torsional vibration characteristic value in the power transmission path from the detector to the second detector is obtained, and the meshing transmission error between the driving gear and the driven gear is calculated based on the torsional vibration characteristic value and the output value of each detector. A method characterized by the following.

[0010]

According to the first aspect of the present invention, the driving gear among the test gears is forcibly rotated, and the driven gear meshed with the driving gear is rotated. In that case, a load may be applied to the driven gear as needed. Then, the rotation of the driving gear is detected by the first detector, and the rotation of the driven gear is detected by the second detector. The meshing transmission error between the driving gear and the driven gear is basically determined by the driving gear. It is obtained as the delay / advance of the rotation of the driven gear with respect to the rotation. On the other hand, a meshing error is measured by using a test gear instead of the driving gear or the driven gear. Since the tooth surface of the test gear is provided with a projection having a known height, a large mesh transmission error occurs corresponding to the projection. Since the meshing transmission error is caused by a projection whose height is known, the ratio between the measured value and the height of the projection is determined by the torsional vibration of the measuring means including the transmission member between each detector or each gear. The characteristic, that is, the rotation amplification factor is represented by the rotation angle, and the true value excluding the influence of the measuring means can be obtained by correcting the measurement result of the meshing transmission error between the driving gear and the driven gear by this ratio. .

According to the second aspect of the present invention, the driving gear and the driven gear are meshed with each other to apply a rotational driving force to the driving gear to rotate these gears. The meshing transmission error is determined as the relative rotation delay / advance of the gear. According to the second aspect of the present invention, the input of known parameters such as frequency and torque is applied to the drive gear to determine the torsional vibration characteristic value of the power transmission system from the first detector to the second detector. The meshing transmission error is calculated based on the torsional vibration characteristic value and the measured value of the delay / lead of the rotation of the driven gear with respect to the rotation of the driving gear. As a result, the true value of the meshing transmission error without the influence of the measuring means is calculated. Can be requested.

[0012]

Next, the present invention will be described based on embodiments. First, a basic configuration of a measuring device for a meshing transmission error will be described. FIG. 1 is a block diagram of a device for a differential gear mechanism (differential gear unit). A motor 1 serving as a rotation driving means is connected to an input shaft of a gear box 2 for increasing and decreasing speed, 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 as a rotation detector is connected to the torque meter 4 via a shaft coupling (Ω coupling) 5.
The drive gear 8 of the differential gear mechanism 7 is connected to the rotary encoder 6.

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

Assuming that the differential gear mechanism 7, which is the test gear, has no errors such as tooth profile error, elastic deformation or pitch error, the rotation of the drive gear 8 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, 9, there is actually a meshing error or an elastic deformation, so that a meshing transmission error occurs between the driving gear 8 and the driven gears 9, 9. 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 the result of measuring the rotational angle difference between the driving gear and the driven gear in a differential gear mechanism comprising a hypoid gear as a meshing transmission error. In FIG. 2, the measurement result shows a convexly curved wave shape due to the occurrence of an error in the tooth profile or elastic deformation of the teeth. This is because the range is a portion where the pitch error is cumulatively increased. When no load is applied, each tooth meshes alone (only one tooth) in a range (one pitch) indicated by a solid line, and when a load is applied, two teeth mesh simultaneously in a range indicated by a broken line. And transmission error e for each tooth
Is represented by the amount of separation of the convex curve from the straight line L.

The above-mentioned meshing transmission error e obtained based on the output signals of the rotary encoders 6, 10 is determined by the rotary encoders 6, 10 by the measuring device shown in FIG.
Is obtained by using the output value of the measurement device as it is, and includes the inherent amount of elastic deformation (vibration) in the measuring apparatus shown in FIG. That is, the rotary encoder 6,
Reference numeral 10 does not directly detect the rotation angles of the gears 8 and 9, but means for transmitting torque is provided between the two. The elastic deformation is added. In order to remove this and obtain a true value, the following correction is performed.

FIG. 3 shows one predetermined tooth 15 of the test gear 14 for that purpose. This test gear 1
Reference numeral 4 denotes a hypoid gear similar to the test gear, and a projection 16 having a known height H is formed at the center of the tooth surface of a predetermined single tooth 15. That is, the tooth surface is a surface that contacts the teeth of the mating gear and transmits torque, and the meshing proceeds in the direction indicated by the arrow. And the projection 16
It is formed in a narrow band shape, and is formed to be inclined in a direction (simultaneous contact line direction) substantially perpendicular to the meshing traveling direction. The width of the projection 16 is set to a width at which the engagement between the projection 16 and the counterpart tooth starts and ends while only the tooth 15 forming the projection 16 engages with the counterpart tooth. I have.

The test 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 projection 16 meshes with the other tooth, the rotation angle of the driven gear increases, and the meshing transmission error actually measured as the rotation angle difference depends on the shape of the projection 16. It will increase accordingly. That is, the waveform temporarily changes greatly. The change amount D is a change amount corresponding to the protrusion 16 under conditions such as an input in which measurement is performed using the test gear 14, and the ratio of the height H of the protrusion 16 to the change amount D ( H
/ D = α) is a characteristic value (amplification factor) caused by elastic deformation of the measuring device under the condition. Therefore, in the present invention, the true value of the meshing transmission error is identified by correcting the actual measured value of the meshing transmission error, that is, the value shown in FIG. 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. Since the transmission error thus obtained does not include factors such as elastic deformation of the measuring means, it accurately represents the 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, the actual measurement and the test need to be performed under substantially the same conditions.
In addition, it is necessary that the rotation speed be low enough not to crush the projection 16 and low enough to prevent the tooth engagement from being disengaged by the acceleration caused by the projection 16 (to the extent that the tooth surface does not separate). Therefore, the following method is advantageous as a more general method.

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

FIG. 5 shows a torsional vibration model of the measuring device shown in FIG.
, A vibration model of a power transmission path as a load through the motor 13 is shown, I is an inertia moment of an inertia body such as a motor or a gear, k is a spring constant of a transmission path between the inertia 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 driving gear 8 and the driven gear 9, which are test gears, respectively. The equation of motion in this vibration model is represented by the following Equation 1.

[0022]

(Equation 1) Note that in equation 1, one dot indicates the first derivative, and two dots indicate the second derivative.

Incidentally, 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 , angular velocity is ω, and 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 gives the amplitude E of the meshing transmission error.
Is as shown in 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 E, respectively.
The phase difference when = 0 is expressed as follows.

Q = .lambda.4 / .lambda.3 B = .lambda.3 / .lambda.2 M = .lambda.4 / .lambda.5 q = .phi.4 -.phi.3 b = .phi.3-.phi.2 m = .phi.4-.phi.5 Since the attenuation on the gear tooth surface is negligibly small, C ₃ = 0 can be set, and eventually E becomes as shown in Expression 4.

[0027]

(Equation 4) That is, the actual engagement transmission error E is obtained by correcting the actual measured values λ ₂ , λ ₅ , (φ ₂ −φ ₅ ) of the rotation angle and the phase difference of the driving gear 8 and the driven gear 9 with the characteristic values of the measuring device. Become. The characteristic values Q, B, M, q, b, and m can be obtained as follows, for example.

FIGS. 6A and 6B show an example of a vibration experiment for obtaining the above characteristic values for the measuring apparatus shown in FIG. 1, and FIG. In the vibration test, a weight 17 is attached to the output side of the gear box 2, and a shaker (shaker) 18 that applies a known vibration 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 using an acceleration sensor 19, and at the same time, to detect the angular velocity and angular acceleration of the rotary encoder 10 on the driven gear 9 side. The rotation state is detected using the acceleration sensor 20. In the vibration test shown in FIG. 6B, the driven gear 9 is given rotational vibration by the vibrator 18 and the rotational state of the drive gear 8 such as angular velocity and angular acceleration is detected by the acceleration sensor 19. The rotational state of the rotary encoder 6 on the driving gear 8 side, such as angular velocity and angular acceleration, is measured by an acceleration
To detect.

Accordingly, the rotation angle λ ₂ and phase φ _{2 of the} rotary encoder 10 and the rotation angle λ ₄ and phase φ _{4 of} the drive gear 8 are obtained from the vibration experiment shown in FIG. Λ ₄ / λ ₂ = Q · B φ ₄ −φ ₂ = q + b 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 values based on the frequency of the input forced vibration. Therefore, when calculating the mesh transmission error, a value at the same frequency as the frequency in the measurement test described below is employed. Will be.

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

In this way, all of the parameters in equation (4) can be known, and by substituting the values into 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 an error caused by the torsional vibration of the measuring device, and therefore, the meshing transmission error of each gear 8, 9 can be known. . In addition, in the above-described vibration experiment, there is no special restriction on the size and frequency of the torque input from the vibration exciter 18, so that the applicable range of the above-described method is widened.

The present invention is not limited to the above embodiment. For example, means for determining the characteristic value of the measuring device
The method is not limited to the two vibration experiments described above, and other means and methods can be adopted as necessary.
For example, the connection position of the vibrator 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 can be applied not only to the measurement of the transmission error of the differential gear but also to the measurement of the transmission error of a general gear. When the above-described protrusion is formed on a predetermined tooth, the protrusion is not limited to forming the protrusion on only one tooth, and the protrusion may be formed on a plurality of teeth. Further, the configuration of the measuring device is not limited to the structure shown in FIG. 1, and the means for applying a rotational force and the means for applying a load may be other than a motor, and the means for detecting rotation is not limited to a rotary encoder.

[0033]

As described above, according to the first aspect of the present invention, the test gears are engaged with each other and rotated, and the relative rotation delay / advance of one of the gears, that is, the mesh transmission error. When measuring the height of the projections with known heights, the rate of increase of the meshing transmission error, i.e., the correction value, is calculated from the measurement results, and the measured value is corrected by the correction value. It is possible to obtain an accurate mesh transmission error which is not affected.

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

[Brief description of the drawings]

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

FIG. 2 is a waveform diagram of an example in which relative delay and advance for each tooth are actually measured as meshing transmission errors.

FIG. 3 is a perspective view showing an example of the shape of a tooth on which a projection is formed.

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

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

FIG. 6 is a schematic diagram for explaining a method of a vibration experiment on the apparatus shown in FIG. 1;

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

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

[Description of Signs] 1 Motor 6, 10 Rotary encoder 7 Differential gear mechanism 8 Drive gear 9 Follower gear 14 Test gear 16 Projection 18 Vibrator 19, 20, 21 Acceleration sensor

Continuation of the front page (56) References JP-A-1-305334 (JP, A) JP-A-1-210839 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01M 13 / 02

Claims (2)

(57) [Claims] 1. A first detector for detecting a rotation state of a driving gear and a second detector for detecting a rotation of the driven gear by rotating a driving gear by rotating driving means and rotating a driven gear meshed with the driving gear. A gear transmission error measuring method for measuring an engagement transmission error between the driving gear and the driven gear based on an output value of a gear, wherein a projection with a known height is formed at a central portion of the tooth surface in the meshing direction. The test gear is used as the drive gear or the driven gear to measure the mesh transmission error and determine the ratio between the measured value of the mesh transmission error due to the projection and the height of the projection to obtain the mesh between the test drive gear and the driven gear. A gear transmission error measuring method, wherein the transmission error measurement result is corrected by the ratio. 2. A first detector for detecting the rotation state of the drive gear and a second detector for detecting the rotation of the driven gear, wherein the rotation drive means rotates the drive gear and rotates a driven gear meshed with the drive gear. A gear transmission error measuring method for measuring a mesh transmission error between the drive gear and the driven gear based on an output value from the device, wherein at least the first detector is provided by giving a predetermined input to the drive gear. Calculating the torsional vibration characteristic value in the power transmission path from the to the second detector, and calculating the meshing transmission error between the driving gear and the driven gear based on the torsional vibration characteristic value and the output value of each of the detectors. A gear transmission error measuring method characterized by the following.