JP2010216590A - Rocking type gear device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply a rocking type gear device improved so as to restrain generation of noise more than conventional noise. <P>SOLUTION: A frequency band of the noise generated due to meshing a first gear g1 being an input shaft gear and a second gear g2 being a rotary member input side gear, and a frequency band of the noise generated due to meshing a fourth gear g4 being an output shaft gear and a third gear g3 being a rotary member output side gear, are set in a different band. Actually, the frequency band of the noise generated due to meshing the input shaft gear and the rotary member inside side gear, and the frequency band of the noise generated due to meshing the output shaft gear and the rotary member output side gear, are set in the different band, by setting the tooth number n1 of the first gear g1 and the tooth number n4 of the fourth gear g4 in the different tooth number. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an oscillating gear device, and more particularly to an oscillating gear device that suppresses noise.

  2. Description of the Related Art Conventionally, a speed reducer using an oscillating gear device is used as a transmission that is small in size and has a high reduction ratio and has high transmission efficiency. For example, a specific example is presented in Patent Document 1. An example will be described with reference to FIGS.

  As shown in FIG. 5, the substantially cylindrical first input shaft 101 is rotatably supported by a substantially cylindrical housing 104 via a bearing 111 and a bearing 121. A first gear g101 (shaft gear), which is a bevel gear, is fixed to the first input shaft 101 with the tooth surface facing the output side (hereinafter simply referred to as “output side”) in the axial direction. . A bearing gear 105 as a rotating member is disposed on the output side of the first gear g101, and the input side in the axial direction of the inner ring 151 of the bearing gear 105 (hereinafter simply referred to as “input side”). Is formed with a second gear g102 (rotating member input side gear) which is a bevel gear. Since the second gear g102 meshes with the first gear g101, the rotation of the first input shaft 101 is transmitted to the bearing gear 105 when the first input shaft 101 is rotating. An outer ring 152 is provided so as to surround the circumferential portion of the inner ring 151 from the outer side (hereinafter simply referred to as “outer side”) in the radial direction, and between the inner ring 151 and the outer ring 152. A bearing gear 105, which is a bearing-integrated gear, is formed by interposing the rolling elements 153. The outer ring 152 is attached so as to rotate integrally with the rotor 102 of the electric motor (not shown). The rotor 102 is supported on the housing 104 by bearings 122 and 123.

  A third gear g103 (rotating member output side gear), which is a bevel gear, is formed on the output side of the inner ring 151 of the bearing gear 105. On the further output side of the third gear g103, an output shaft 103 is rotatably supported on the housing 104 via a bearing 112 and a bearing 124. A fourth gear g104, which is a bevel gear, is fixed to the output shaft 103 with the tooth surface facing the input side. Since the third gear g103 is engaged with the fourth gear g104, the rotation transmitted to the bearing gear 105 is transmitted to the output shaft 103. The first input shaft 101 and the output shaft 103 have the same rotation shaft 106.

  The structure of the first gear g101 will be described more specifically. A portion of the first gear g101 that meshes with the second gear g102 is enlarged, and as shown in FIG. 6 displayed as a schematic diagram, the first gear g101 is formed with a semi-cylindrical concave groove g111. A cylindrical rolling element g112 is supported in the concave groove so as to be able to roll. Since the cylindrical rolling element g112 is supported in the semi-cylindrical concave groove, approximately half of the outer peripheral surface of the rolling element g112 protrudes to the second gear g102 side (output side), and this protruding portion is It functions as a convex tooth of the first gear g101. On the other hand, a concave groove similar to the concave groove g111 formed in the first gear g101 is formed in the second gear g102, and this concave groove functions as a concave tooth of the second gear g102.

  Here, since the second gear g102, which is the bevel gear, is meshed with the first gear g101, which is the bevel gear, the manner in which the force is applied at the meshing portion changes at the start and end of meshing of the gear. This change in how the force is applied is mitigated by the rolling element g112 rolling in the a1 direction and moving in the a2 direction.

  Furthermore, in Patent Document 1, the retainer that supports the rolling elements (rollers) from the outside and the inside in the a2 direction (tooth trace direction) is an elastic member, so that the rolling elements are in the a2 direction (tooth traces) when engaged. It is proposed to have a structure that allows movement in the direction). With such a configuration, it is described that “displacement in the tooth trace direction is possible against elasticity, and the frictional force between the end surface of the roller and the outer peripheral surface of the retainer is greatly reduced ([0008])”. Yes.

JP 2007-247741 A

  However, according to the technology according to Patent Document 1, if the frictional force between the end surface of the roller and the outer peripheral surface of the retainer is significantly reduced, even if noise caused by friction is suppressed, Not all the noise generated by the oscillating gear device is suppressed.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an oscillating gear device that is improved so as to suppress the generation of noise as compared with the conventional art.

  An oscillating gear device according to the present invention includes an input shaft gear provided at an axial end portion of an input side rotary shaft, an output shaft gear provided at an axial end portion of an output side rotary shaft, and the input side rotary shaft. A rotating member that rotates eccentrically with respect to the shaft center of the rotating member, and a rotating member on the rotating member input side that is provided at an axial end of the rotating member and meshes with the input shaft gear An oscillating gear device provided with a gear and a rotating member output side gear meshed with the output shaft gear while being provided at an axial end of the rotating member. Further, a frequency band of noise generated when the input shaft gear meshes with the rotating member input side gear, and a frequency band of noise generated when the output shaft gear meshes with the rotating member output side gear. Are different bands.

  According to the above configuration, the frequency band of noise generated when the input shaft gear and the rotary member input side gear mesh with each other, and the frequency band of noise generated when the output shaft gear and the rotary member output side gear mesh with each other. Since the frequency bands are different from each other, the frequency peaks at which noise is generated are dispersed, and unpleasant noise can be suppressed.

  In the oscillating gear device according to the present invention, the number of teeth of the input shaft gear and the number of teeth of the output shaft gear are different from each other, whereby the input shaft gear and the rotating member input side gear mesh with each other. It is preferable that the frequency band of the noise generated in order to be different from the frequency band of the noise generated because the output shaft gear and the rotating member output side gear mesh with each other.

  According to the above configuration, since the number of teeth of the input shaft gear and the number of teeth of the output shaft gear are different, the frequency band of the generated noise can be easily made different. Therefore, the frequency band of noise generated when the input shaft gear and the rotating member input side gear mesh with each other, and the frequency band of noise generated when the output shaft gear and the rotating member output side gear mesh with each other are different. For this reason, the frequency peaks at which noise is generated are dispersed, and noise that causes discomfort can be suppressed.

  The oscillating gear device according to the present invention includes a frequency band that is an integral multiple of a frequency band of noise generated when the input shaft gear and the rotating member input side gear mesh with each other, the output shaft gear, and the rotating member. It is preferable to suppress noise generation by making the frequency band of noise generated by meshing with the output side gear further different.

  According to the above configuration, a frequency band that is an integral multiple of the frequency band of the noise generated when the input shaft gear and the rotating member input side gear mesh with each other, and the output shaft gear and the rotating member output side gear mesh with each other. The frequency band of noise to be generated is further different. Therefore, the harmonic frequency band of the noise generated when the input shaft gear and the rotating member input side gear mesh with each other, that is, the secondary noise peak, the tertiary noise peak, the output shaft gear and the rotating member output side gear. It is also possible to prevent the noise peaks generated by meshing with each other. Therefore, noise generation can be further suppressed.

  The oscillating gear device according to the present invention includes a frequency band of noise generated by meshing of the input shaft gear and the rotating member input side gear, and meshing of the output shaft gear and the rotating member output side gear. It is preferable to suppress the generation of noise by making the frequency band that is an integral multiple of the frequency band of the noise generated by this further different band.

  According to the above configuration, the frequency band of the noise generated when the input shaft gear and the rotating member input side gear mesh with each other, and the frequency band of the noise generated when the output shaft gear and the rotating member output side gear mesh with each other. An integer multiple frequency band is set to a further different band. Therefore, the harmonic frequency band of the noise generated by the meshing of the output shaft gear and the rotating member output side gear, that is, the secondary noise peak, the tertiary noise peak, the input shaft gear and the rotating member input side gear It is also possible to prevent the noise peaks generated by meshing with each other. Therefore, noise generation can be further suppressed.

  According to the present invention, it is possible to supply an oscillating gear device that is improved so as to suppress the generation of noise as compared with the conventional art.

It is drawing explaining one Embodiment of the rocking | fluctuation type gear apparatus concerning this invention, Comprising: It is an axial sectional view. BRIEF DESCRIPTION OF THE DRAWINGS It is drawing explaining one Embodiment of the rocking | fluctuation type gear apparatus concerning this invention, Comprising: (a) is a partial expansion schematic diagram about the meshing part of a 1st gear-a 4th gear, (b) is 1st. It is an enlarged view about the meshing part of a gearwheel and a 2nd gearwheel. FIG. 3 is a diagram for explaining an embodiment of the oscillating gear device according to the present invention, and is a partially enlarged view of the first gear as seen from the AA direction in FIG. 2. BRIEF DESCRIPTION OF THE DRAWINGS It is drawing explaining one Embodiment of the rocking | fluctuation type gear apparatus concerning this invention, Comprising: It is a graph which shows the sound pressure of noise for every frequency, (a) is rotation speed 1rad / s of an output shaft, (b). Is the case where the rotational speed of the output shaft is 2 rad / s, (c) is the rotational speed of the output shaft is 3 rad / s, and (d) is the rotational speed of the output shaft is 4 rad / s. It is drawing explaining the conventional oscillating gear apparatus, Comprising: It is an axial sectional view. It is drawing explaining the conventional oscillating gear apparatus, Comprising: It is a partially expanded view of a 1st gearwheel. It is drawing explaining the conventional rocking | fluctuation type gear apparatus, Comprising: It is a graph which shows the sound pressure of noise for every frequency, (a) is the rotation speed 1rad / s of an output shaft, (b) is the rotation speed of an output shaft. 2 rad / s, (c) is the case where the rotational speed of the output shaft is 3 rad / s, and (d) is the case where the rotational speed of the output shaft is 4 rad / s.

Hereinafter, an embodiment of an oscillating gear device embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, the oscillating gear device according to the present embodiment includes a substantially cylindrical housing 4, a substantially columnar first input shaft 1 inserted into the housing, and a substantially cylindrical second input. The shaft includes a rotor 2, a substantially cylindrical output shaft 3, and first to fourth gears, each of which is supported via a bearing. That is, it is a rocking gear device having two input shafts and one output shaft. This oscillating gear device is applied, for example, to a steering device of an automobile, and is applied to a transmission ratio variable mechanism that varies the turning angle of the wheel with respect to the rotation of the steering wheel.

  The substantially cylindrical first input shaft 1 is rotatably supported by a substantially cylindrical housing 4 via a bearing 11 and a bearing 21. Further, the first input shaft 1 includes a first gear g1 (shaft gear), which is an input shaft gear and a bevel gear, having a tooth surface in the axial direction on the output side (hereinafter simply referred to as “output side”). It is fixed toward. A bearing gear 5 that is a rotating member is disposed on the output side of the first gear g1. On the input side (hereinafter simply referred to as “input side”) in the axial direction of the inner ring 51 of the bearing gear 5, a second gear g2 (rotary member input side gear) that is a rotating member input side gear and a bevel gear is provided. ) Is formed. Since the second gear g2 meshes with the first gear g1, the rotation of the first input shaft 1 is transmitted to the bearing gear 5 when the first input shaft 1 is rotating. An outer ring 52 is provided so as to surround the circumferential portion of the inner ring 51 from the outside (hereinafter simply referred to as “outside”) in the radial direction, and between the inner ring 51 and the outer ring 52. A bearing gear 5 that is a bearing-integrated gear is formed by interposing the rolling elements 53. The outer ring 52 is attached to the rotor 2 of an electric motor (not shown) so as to rotate integrally. The rotor 2 is rotatably supported by the housing 4 via bearings 22 and 23.

  Further, on the output side of the inner ring 51 of the bearing gear 5, a third gear g3 (rotating member output side gear) that is a bevel gear and a rotating member output side gear is formed. On the further output side of the third gear g3, the output shaft 3 is rotatably supported by the housing 4 via the bearing 24 and the bearing 12. A fourth gear g4, which is an output shaft gear and a bevel gear, is fixed to the output shaft 3 with the tooth surface facing the input side. Since the fourth gear g4 meshes with the third gear g3, the rotation transmitted to the bearing gear 5 is transmitted to the output shaft 3. The first input shaft 1 and the output shaft 3 have the same rotation shaft 6.

  A rotor 2 that is a substantially cylindrical second input shaft is supported on the housing 4 via a bearing 22 and a bearing 23 so as to surround the first gear g1 to the fourth gear g4 from the outside. The inner peripheral surface 25 of the rotor 2 has a cylindrical shape that is eccentric with respect to the rotating shaft 6. Further, the outer ring 52 of the bearing gear 5 described above is fitted into the inner peripheral surface 25. As a result, the outer ring 52 and the bearing gear 5 are provided in an eccentric state with respect to the rotating shaft 6.

First, the relationship between the input from the first input shaft 1 and the rotor 2 as the second input shaft and the output shaft 3 will be described.
First, the case where the rotor 2 as the second input shaft is fixed in the state of FIG. 1 and the first input shaft 1 is in the rotating state will be described. Since the rotor 2 is fixed, the outer ring 52 of the bearing gear 5 fitted therein is also fixed. Therefore, the bearing gear 5 is kept in a state where its rotation shaft is fixed. In this state, the rotation of the first input shaft 1 is transmitted to the inner ring 51 of the bearing gear 5 via the first gear g1 and the second gear g2, and the rotation transmitted to the inner ring 51 is transmitted to the third gear. Since the rotation is transmitted to the output shaft 3 via g3 and the fourth gear g4, the rotation of the first input shaft 1 is decelerated according to the gear ratio of the first gear g1 to the fourth gear g4 to the output shaft 3. Communicated.

  Next, the case where the first input shaft 1 is fixed in the state of FIG. 1 and the rotor 2 as the second input shaft is in a rotating state will be described. Since the rotor 2 is rotating, the outer ring 52 of the bearing gear 5 fitted therein also rotates. Here, since the inner peripheral surface 25 of the rotor 2 has a cylindrical shape eccentric with respect to the rotating shaft 6, the entire bearing gear 5 rotates via the outer ring 52 while changing the eccentric shaft. To exercise. Here, since the first input shaft 1 is fixed, the rotation of the rotor 2 is transmitted to the bearing gear 5 via the outer ring 52, and the rotation transmitted to the bearing gear 5 is the third gear g3 and Since the rotation is transmitted to the output shaft 3 via the fourth gear g4, the rotation of the rotor 2 is decelerated according to the gear ratio of the first gear g1 to the fourth gear g4 and transmitted to the output shaft 3. As described above, when either the first input shaft 1 or the rotor 2 as the second input shaft is fixed, the rotation from the non-fixed input shaft is performed by the first gear g1 to the fourth gear g4. Is decelerated in accordance with the gear ratio and transmitted to the output shaft 3.

  Furthermore, the case where the rotor 2 which is the 1st input shaft 1 and the 2nd input shaft in the state of FIG. 1 is in a rotation state is demonstrated. In this case, the entire bearing gear 5 swings to transmit the rotation of the rotor 2 as the second input shaft to the output shaft 3 and also transmits the rotation of the first input shaft 1 to the output shaft 3. Is done. Therefore, the rotation of the first input shaft 1 and the rotation of the rotor 2 as the second input shaft can be transmitted to the output shaft 3. Thus, when neither the first input shaft 1 nor the rotor 2 as the second input shaft is fixed, the rotation from the first input shaft 1 and the rotor 2 as the second input shaft is not performed. The speed is reduced according to the gear ratio of the first gear g1 to the fourth gear g4 and is transmitted to the output shaft 3. That is, the transmission ratio from the first input shaft 1 to the output shaft 3 can be freely changed by controlling the rotation of the rotor 2 as the second input shaft.

  Next, the reduction ratio will be described separately for each case. First, a case where the rotor 2 as the second input shaft is fixed and the first input shaft 1 is in a rotating state will be described. The rotation of the first input shaft 1 is transmitted to the bearing gear 5 in accordance with the ratio of the number of teeth n1 of the first gear g1 and the number of teeth n2 of the second gear g2, that is, n1 / n2. For example, if the number of teeth n1 of the first gear g1 is 38 and the number of teeth n2 of the second gear g2 is 40, the first input shaft 1 makes one revolution and the first gear g1 makes one revolution. The two gears g2 rotate 38/40, and the rotation of the first input shaft 1 is transmitted to the bearing gear 5. That is, in this case, the first stage deceleration of 38/40 is performed.

  Similarly, the rotation of the rotor 2 as the second input shaft is transmitted to the bearing gear 5 in accordance with the ratio of the number of teeth n3 of the third gear g3 and the number of teeth n4 of the fourth gear g4, that is, n3 / n4. The For example, if the number of teeth n3 of the third gear g3 is 40 and the number of teeth n4 of the fourth gear g4 is 40, the inner ring 51 of the bearing gear 5 makes one rotation and the third gear g3 makes one rotation. The four gears g4 rotate 40/40, and the rotation of the first input shaft 1 is transmitted to the bearing gear 5. That is, in this case, 40/40 second-stage deceleration is performed. Therefore, the rotation of the first input shaft 1 is decelerated at a reduction ratio of n3 / n4 × n1 / n2 = (n1 · n3) / (n2 · n4) due to the deceleration of the first stage and the second stage. It becomes. In the above example, 38/40 × 40/40 = (40 · 38) / (40 · 40) = 0.95, that is, a reduction ratio of about 95.0% is obtained.

  Next, the case where the first input shaft 1 is fixed and the rotor 2 as the second input shaft is in a rotating state will be described. The rotation of the rotor 2 is transmitted to the inner ring 51 of the bearing gear 5 corresponding to the difference between the number of teeth n1 of the first gear g1 and the number of teeth n2 of the second gear g2, that is, n2−n1. For example, if the number of teeth n1 of the first gear g1 is 38 and the number of teeth n2 of the second gear g2 is 40, when the outer ring 52 rotates once by rotating the rotor 2 once, the second gear g2 becomes 40−. The rotation of the rotor 2 is transmitted to the inner ring 51 as a rotation of 38, that is, two teeth. Therefore, the reduction ratio is (n2-n1) / n2. That is, in this case, the first-stage deceleration of (40-38) / 40 is performed.

When the rotor 2 as the second input shaft is in a rotating state, on the one hand, the rotor 2 corresponds to the difference between the number of teeth n4 of the fourth gear g4 and the number of teeth n3 of the third gear g3, that is, n4−n3. Is transmitted to the output shaft 3 through the bearing gear 5. For example, if the number of teeth n3 of the third gear g3 is 40 and the number of teeth n4 of the fourth gear g4 is 40, the inner ring 51 of the bearing gear 5 makes one rotation and the third gear g3 makes one rotation. The rotation of the rotor 2 is transmitted to the output shaft 3 as the four gears g4 rotate 40-40, that is, 0 teeth. Therefore, the reduction ratio is (n4-n3) / n4. Here, since the number of rotations of the third gear g3 is reduced by the ratio between the number of teeth n1 of the first gear g1 and the second gear g2 by the first-stage deceleration, (n4−n3) / n4 × n1 / n2 That is, in this case, the second-stage deceleration of (40-40) / 40 × 38/40 is performed. Therefore, combining the first stage deceleration and the second stage deceleration,
(N2-n1) / n2 + (n4-n3) / n4 × n1 / n2
That is, (40−38) / 40 + ((40−40) / 40 × 38/40
= 0.05
That is, a reduction ratio of about 5.00% is obtained.

  As described above, the reduction ratio can be freely changed by changing the number of teeth n1 to n4 of the first gear g1 to the fourth gear g4, and particularly with respect to the input from the rotor 2 as the second input shaft. It is possible to easily obtain a large reduction ratio.

  Incidentally, FIG. 2A schematically showing the meshing portion between the first gear g1 and the second gear g2, and FIG. 2B showing the meshing portion between the first gear g1 and the second gear g2 in an enlarged manner. As shown in FIG. 1, a semi-cylindrical concave groove g11 is formed in the first gear g1, and a cylindrical rolling element g12 is supported in the concave groove g11 so as to be able to roll. Since the cylindrical rolling element g12 is supported by the semi-cylindrical concave groove g11, approximately half of the outer peripheral surface of the rolling element g12 protrudes toward the second gear g2, and this protruding portion is the first gear. It functions as a convex tooth of g1. On the other hand, a concave groove g21 similar to the concave groove g11 formed in the first gear g1 is formed in the second gear g2. The concave groove g21 functions as a concave tooth of the second gear g2. That is, the portion of the rolling element g12 that protrudes toward the second gear g2 meshes with the concave groove g21 of the second gear g2. Therefore, the sliding that occurs when the rolling element g12 and the concave groove g21 are engaged is absorbed by the rolling of the rolling element g12 indicated by the arrow a1 in FIG. Therefore, since it is not necessary to provide a backlash, the meshing adjustment can be performed accurately, and vibration and noise can be reduced. Further, since a preload can be applied between the gears, the meshing adjustment can be performed more precisely, and vibration and noise can be reduced.

  Similarly, a semi-cylindrical concave groove g41 is formed in the fourth gear g4, and a cylindrical rolling element g42 is rotatably supported in the concave groove g41. Since the cylindrical rolling element g42 is supported in the semi-cylindrical concave groove g41, approximately half of the outer peripheral surface of the rolling element g42 protrudes toward the third gear g3, and this protruding portion is the fourth gear. It functions as a convex tooth of g4. On the other hand, a concave groove g31 similar to the concave groove g41 formed in the fourth gear g4 is formed in the third gear g3. The concave groove g31 functions as a concave tooth of the third gear g3. That is, the portion of the rolling element g42 that protrudes toward the third gear g3 meshes with the concave groove g31 of the third gear g3. Therefore, the sliding that occurs when the rolling element g42 and the concave groove g31 are engaged is absorbed by the rolling of the rolling element g42. Therefore, since it is not necessary to provide a backlash, the meshing adjustment can be performed accurately, and vibration and noise can be reduced. Further, since a preload can be applied between the gears, the meshing adjustment can be performed more precisely, and vibration and noise can be reduced.

  The structure of the first gear g1 will be described more specifically. As shown in FIG. 3 in which the portion of the first gear g1 that meshes with the second gear g2 is shown as a partially enlarged view from the AA direction in FIG. 2, the first gear g1 has a semi-cylindrical concave groove g11. And a cylindrical rolling element g12 is supported in the groove so as to be able to roll. Since the cylindrical rolling element g12 is supported by the semi-cylindrical concave groove, approximately half of the outer peripheral surface of the rolling element g12 protrudes to the second gear g2 side (output side), and this protruding portion is It functions as a convex tooth of the first gear g1. On the other hand, a concave groove g21 similar to the concave groove g11 formed in the first gear g1 is formed in the second gear g2, and this concave groove g21 functions as a concave tooth of the second gear g2. With this structure, the rolling element g12 whose protruding portion functions as the convex teeth of the first gear g1 moves linearly in the direction indicated by the arrow a2, thereby further causing sliding that occurs when the rolling element g12 meshes with the groove g21. Absorbed. This also makes it possible to precisely adjust the meshing as described above, and to reduce vibration and noise.

FIG. 7 shows an example of the result of measuring the noise of the oscillating gear device having the general reduction ratio described above with the sound collector 8 shown in FIG. The output shaft 3 was rotated by fixing the first input shaft 1 and rotating the rotor 2, and noise was measured for each rotation speed. FIGS. 7A to 7D are graphs showing the relationship between the sound pressure and the frequency at which noise is generated at the rotation speed of the output shaft 3 of 1 to 4 rad / s, respectively. As described above, the tooth number ratio of g1 to g4 is as follows.
g1: g2: g3: g4 = n1: n2: n3: n4 = 38: 40: 40: 40.

  Although it is not clear in the case of the rotational speed 1 rad / s of the output shaft 3 shown in FIG. 7A, the higher the rotational speed, the more predetermined the rotational speed after the rotational speed 2 rad / s shown in FIG. The sound pressure at the frequency is observed as a peak. As shown in the figure, this is considered to occur in a specific frequency band proportional to the number of teeth n1 to n4 of each of the gears g1 to g4. That is, the peaks similar to those seen in the vicinity of 250 Hz, 500 Hz, and 750 Hz in FIG. 7B · 2 rad / s are the same as those shown in FIG. 7C · 3 rad / s and around 375 Hz, 750 Hz, and 1025 Hz. ) ・ It is seen in the vicinity of 500 Hz, 1000 Hz and 1500 Hz at 4 rad / s. Compared to the case of 2 rad / s, similar peaks occur in frequency bands of 1.5 times and 2 times, respectively. Therefore, the noise peak in the specific frequency band depends on the number of gear teeth. It is thought that. That is, it is considered that the noise proportional to the number of teeth and the number of rotations is peaked in FIGS. In addition, when the lowest frequency peak is used as a reference, a double peak and a triple peak appear, and therefore the high frequency side peak is considered to be a second harmonic peak and a third harmonic peak, respectively. Hereinafter, the peak of the lowest frequency is set as the primary peak, and the peak on the high frequency side is set as the secondary peak and the tertiary peak in order.

  By the way, it is known that even if the total amount of sound pressure is the same, noise having a peak in a specific frequency band is felt uncomfortable. On the contrary, noise in which sound pressure is uniformly distributed in all wavelength bands is called white noise, and it is known that the degree of discomfort is small.

  On the other hand, in the example described above, since the number of teeth n1 to n4 of the gears g1 to g4 is only 38 and the others are all 40, they resonate with each other and have the primary peak and the secondary peak in the same frequency band. It is thought that noise having a third order peak was generated.

  Therefore, in the present embodiment, the frequency band of noise generated when the first gear g1 that is the input shaft gear meshes with the second gear g2 that is the rotation member input side gear, and the fourth frequency that is the output shaft gear. The frequency band of the noise generated when the gear g4 and the third gear g3 which is the rotating member output side gear mesh with each other is set to a different band. Specifically, the noise generated when the input shaft gear and the rotating member input side gear mesh with each other by making the number of teeth n1 of the first gear g1 and the number of teeth n4 of the fourth gear g4 different. And the frequency band of noise generated due to the meshing of the output shaft gear and the rotating member output side gear are different bands. With such a configuration, the frequency band in which noise is generated is dispersed, and the amount of noise felt can be reduced.

For example,
4A to 4G are graphs showing the relationship between the frequency at which noise occurs and the sound pressure when g1: g2: g3: g4 = n1: n2: n3: n4 = 38: 40: 20: 20. d). The measurement conditions were the same as described above. The first input shaft 1 was fixed, the rotor 2 was rotated, the output shaft 3 was rotated, and the noise was measured for each rotation speed.

  As shown in FIGS. 4A to 4C, in the low rotation range, the occurrence of the conspicuous peak of the sound pressure seen in FIGS. 7A to 7C is suppressed. On the other hand, in the case of 4 rad / s shown in FIG. 4D, five sound pressure peaks are recognized. This is in order from the lowest frequency, the (primary) resonance peak of the gear g4, the combined peak of the (primary) resonance peak of the gear g1 and the harmonic (secondary) resonance peak of the gear g4, and the third harmonic (third order) of the gear g4. ) The resonance peak, the harmonic overtone (secondary) resonance peak of the gear g1, and the third overtone (third order) resonance peak of the gear g1. Therefore, the generation of the sound pressure peak is suppressed in the low rotation region, and although the peak occurs in the high rotation region, it has been successfully dispersed.

The reduction ratio in this case is calculated.
(N2-n1) / n2 + (n4-n3) / n4 × n1 / n2
That is, (40−38) / 40 + ((20−20) / 20 × 38/40
= 0.05
That is, the reduction ratio is about 5.00%, which is not different from the above example. In other words, if the number of teeth of n3 and n4 are equal, the secondary reduction ratio is always 0, so it is confirmed that n3 and n4 can be set without affecting the overall reduction ratio. The

According to the oscillating gear device of the above embodiment, the following effects can be obtained.
(1) According to the oscillating gear device of the above embodiment, the frequency band of noise generated due to the meshing of the first gear g1 that is the input shaft gear and the second gear g2 that is the rotating member input side gear; Since the frequency band of the noise generated when the fourth gear g4 which is the output shaft gear and the fourth gear g4 which is the rotating member output side gear mesh with each other is different, the frequency peak where the noise is generated is dispersed. , Can suppress unpleasant noise.

  (2) According to the oscillating gear device of the above embodiment, the number of teeth n1 of the first gear g1 that is the input shaft gear and the number of teeth n4 of the fourth gear g4 that is the output shaft gear are different. The frequency band of the generated noise can be easily made different. Therefore, the frequency band of noise generated when the first gear g1 and the second gear g2 that is the rotating member input side gear mesh with each other, and the fourth gear g4 and the third gear g3 that is the rotating member output side gear. Since the frequency band of the noise generated for meshing is set to a different band, the frequency peak at which the noise is generated is dispersed, and noise that causes discomfort can be suppressed.

In addition, you may change the said embodiment as follows.
In the above embodiment,
Although the case where g1: g2: g3: g4 = n1: n2: n3: n4 = 38: 40: 20: 20 was shown, other configurations may be used.
That is, since it is sufficient that the overall reduction ratio is not changed, the number of teeth n3 and the number of teeth n4 may be set to the same number of teeth. For example, the noise generated when the fourth gear g4 and the third gear g3 mesh with a frequency band that is an integral multiple of the frequency band of the noise generated when the first gear g1 and the second gear g2 mesh. Noise generation may be suppressed by setting the frequency band to a different band. According to this configuration, the first gear g1 and the second gear g2 are engaged when the fourth gear g4 and the third gear g3 mesh with a frequency band that is an integral multiple of the frequency band of the noise generated by the meshing. The frequency band of the noise to be generated can be further different. Accordingly, the harmonic overtone frequency band of the noise generated by the engagement of the first gear g1 and the second gear g2, that is, the secondary noise peak, the tertiary noise peak, the fourth gear g4 and the third gear g3, It is also possible to prevent the noise peaks generated by meshing with each other. Therefore, noise generation can be further suppressed.

More specifically, it is sufficient that the number of teeth n4 does not coincide with an integer multiple of the number of teeth n1, for example,
g1: g2: g3: g4 = n1: n2: n3: n4 = 38: 40: 57: 57
It is also good.

  Furthermore, an integer multiple of the frequency band of noise generated by the engagement of the first gear g1 and the second gear g2 and the frequency band of noise generated by the engagement of the fourth gear g4 and the third gear g3 The generation of noise may be suppressed by making the frequency band different from that of the frequency band. According to this configuration, the frequency band of the noise generated when the first gear g1 and the second gear g2 mesh with each other, and the frequency band of the noise generated when the fourth gear g4 and the third gear g3 mesh with each other. An integer multiple frequency band is set to a further different band. Therefore, the harmonic overtone frequency band of the noise generated by the engagement of the fourth gear g4 and the third gear g3, that is, the second noise peak, the third noise peak, the first gear g1 and the second gear g2, It is also possible to prevent the noise peaks generated by meshing with each other. Therefore, noise generation can be further suppressed.

More specifically, the integral multiple of the number of teeth n4 of the fourth gear g4 and the number of teeth n1 of the first gear g1 do not have to match,
g1: g2: g3: g4 = n1: n2: n3: n4 = 38: 40: 28: 28
It is also good.

  In the above embodiment, maintaining the state where the number of teeth n3 of the third gear and the number of teeth n4 of the fourth gear g4 are the same, without affecting the overall reduction ratio, the number of teeth n1 and the number of teeth Although the number n4 is a different number, other configurations may be used. In short, since it is only necessary to change the overall reduction ratio, the number of teeth n1 to n4 may be adjusted as a whole, and the number of teeth n1 and the number of teeth n4 may be different. Even in this case, generation of noise can be similarly suppressed.

  Since the present invention relates to a rocking gear device in which noise is suppressed, the present invention can be widely used for devices that are small and require a high reduction ratio.

  DESCRIPTION OF SYMBOLS 1 ... 1st input shaft, 2 ... Rotor (2nd input shaft), 3 ... Output shaft, 4 ... Housing, 5 ... Bearing gear (rotating member), 6 ... Rotating shaft, 8 ... Sound collector, 11 ... Bearing, 12 ... Bearing, 21 ... Bearing, 22 ... Bearing, 23 ... Bearing, 25 ... Inner circumferential surface, 51 ... Inner ring, 52 ... Outer ring, 53 ... Rolling element, 55 ... Retainer, g1 ... First gear (input shaft) Gear), g2 ... second gear (rotating member input side gear), g3 ... third gear (rotating member output side gear), g4 ... fourth gear (output shaft gear), g11 ... concave groove, g12 ... rolling element, g21 ... concave groove, g31 ... concave groove, g41 ... concave groove, g42 ... rolling element, 101 ... first input shaft, 102 ... rotor (second input shaft), 103 ... output shaft, 104 ... housing, 105 ... Bearing gear 106 ... Rotating shaft 111 ... Bearing 121 ... Bearing 122 ... Bearing 123 ... Bearing 51 ... Inner ring, 152 ... Outer ring, 153 ... Rolling element, g101 ... First gear (input shaft gear), g102 ... Second gear (rotating member input side gear), g103 ... Third gear ((rotating member output side gear)) , G104 ... fourth gear (output shaft gear).

Claims (4)

An input shaft gear provided at the axial end of the input side rotating shaft;
An output shaft gear provided at the axial end of the output-side rotary shaft;
A rotation member that rotates eccentrically with respect to the axis of the input-side rotation shaft, and whose rotation center shaft swings;
A rotating member input-side gear that is provided at an axial end of the rotating member and meshes with the input shaft gear;
In the oscillating gear device, which is provided at an end portion in the axial direction of the rotating member and includes a rotating member output side gear meshing with the output shaft gear,
A frequency band of noise generated when the input shaft gear and the rotating member input side gear mesh with each other, and a frequency band of noise generated when the output shaft gear and the rotating member output side gear mesh with each other. An oscillating gear device characterized by having different bands.   By making the number of teeth of the input shaft gear and the number of teeth of the output shaft gear different from each other, a frequency band of noise generated when the input shaft gear meshes with the rotating member input side gear, 2. The oscillating gear device according to claim 1, wherein a frequency band of noise generated when the output shaft gear and the rotating member output side gear mesh with each other is set to a different band.   Generated when the output shaft gear and the rotating member output side gear mesh with a frequency band that is an integral multiple of the frequency band of the noise generated when the input shaft gear meshes with the rotating member input side gear. The oscillating gear device according to claim 1 or 2, wherein noise generation is suppressed by making the frequency band of noise further different.   An integer of a frequency band of noise generated when the input shaft gear meshes with the rotating member input side gear and a frequency band of noise generated when the output shaft gear meshes with the rotary member output side gear The oscillating gear device according to claim 1 or 2, wherein noise generation is suppressed by making the doubled frequency band further different.

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