JP2007333163A - Step-up/reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively absorb vibration generated in a housing of a step-up/reduction gear. <P>SOLUTION: The step-up/reduction gear 10 has the housing 20; an input shaft 30 projected from the rear part of the housing 20; an output shaft 40 projected from the front part of the housing 20; and a step-up/reduction mechanism enclosed in the housing 20. A vibration restraining mechanism 50 comprises a dynamic vibration absorber 60 and a pair of brackets 70 mounted to a bearing part 28. The dynamic vibration absorber 60 has a weight 62 having predetermined mass and provided at a mounting surface 72 formed at the upper face of the bracket 70; a diaphragm 64 supporting the weight 62 displaceably in the vibrating direction of the housing 20; and a friction generating part 66 restraining the movement of the diaphragm 64. A sliding body 84 is operated integrally with the weight 62 and the diaphragm 64 and given frictional force by sliding along a friction member 86 held at the inner periphery of the friction generating part 66. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an increase / decrease device, and more particularly to an increase / decrease device in which a transmission mechanism configured to decelerate or increase the rotation of an input shaft and transmit the rotation to an output shaft is accommodated inside a housing.

  For example, in an increase / decrease device having a transmission mechanism configured to decelerate or increase the rotation of the input shaft and transmit the rotation to the output shaft, vibration associated with mechanical operation occurs. In the case where such vibration is transmitted to the housing that houses the transmission mechanism and has a frequency that matches the natural frequency of the housing, the housing may resonate and generate vibration noise. Such an oscillating sound may be recognized as noise in an environment where quietness is required (for example, a clean room). In such a case, noise countermeasures are required.

  As this type of noise countermeasure (soundproof countermeasure), there are, for example, a motor serving as a driving source, a speed increasing / reducing gear that transmits rotation of the motor, and a driven device driven by the output shaft of the speed increasing / decreasing device (various devices ) Is covered with a soundproof cover to cut off the source of noise.

  However, since the above-described soundproof cover has a considerably large configuration, not only the manufacturing cost is increased, but also the installation space is increased, so that an inexpensive and compact configuration is desired. In response to such a demand, it has been studied to directly take a countermeasure against vibration in the speed increase / decrease device that is the source of vibration noise.

For example, an active vibration damping device (for example, refer to Patent Document 1) that drives a weight having a predetermined mass to the speed reducer with a hydraulic cylinder, or supports the weight with a spring member and uses the magnetic force of a permanent magnet. There is a passive vibration control device (see, for example, Patent Document 2) in which a weight performs a vibration control operation according to vibration.
JP-A-7-91486 Japanese Patent Laid-Open No. 11-257421

  However, since the vibration damping device described in Patent Document 1 has a configuration in which the weight is driven by a hydraulic cylinder, a control circuit for controlling the hydraulic cylinder and a valve for supplying or discharging hydraulic oil are provided. Therefore, a more complicated configuration than that of the speed increase / decrease device is mounted, and there arises a problem that a balance cannot be maintained in terms of cost and configuration.

  Further, since the vibration damping device described in Patent Document 2 uses the magnetic force of a permanent magnet, there arises a problem that its use in an environment where magnetic force is hated is limited.

  Therefore, in view of the above circumstances, an object of the present invention is to provide an speed increase / decrease device that solves the above-described problems.

  In order to solve the above problems, the present invention has the following means.

  The present invention provides a speed increasing / decreasing device having a housing and a transmission mechanism that is housed in the housing and transmits the rotation of the input shaft to the output shaft by decelerating or increasing the speed of the input shaft. The above-described problem is solved by providing the housing with a dynamic vibration absorber that absorbs vibration of the housing.

  It is preferable that the dynamic vibration absorber is detachably provided on the outer wall of the housing.

  The dynamic vibration absorber includes a weight having a predetermined mass, an elastic support part that supports the weight so as to be displaceable in a vibration direction of the housing, and a suppression unit that suppresses the movement of the elastic support part. Solve the above problems.

  The elastic support part is preferably made of a metal plate that is elastically deformed according to a load.

  The dynamic vibration absorber is preferably provided integrally with the outer wall of the housing.

  The dynamic vibration absorber includes a weight having a predetermined mass, an elastic support portion that is formed integrally with the housing and supports the weight so as to be displaceable in a vibration direction, and a suppression unit that suppresses the movement of the elastic support portion. By solving, the above-mentioned problem is solved.

  The said suppression means solves the said subject by providing the friction member which provides a frictional force by the displacement of the said elastic support part.

  The housing includes a flange portion that accommodates the transmission mechanism, and a bearing portion that accommodates an output shaft that is smaller than the flange portion, and is configured to absorb dynamic vibration in a space defined by the flange portion and the bearing portion of the housing. It is desirable to place a vessel.

  According to the present invention, since the housing is provided with the dynamic vibration absorber that absorbs the vibration of the housing that is generated by the operation of the transmission mechanism, the vibration frequency that is generated by the operation of the transmission mechanism matches the natural frequency of the housing. Resonance can be effectively prevented, and in particular, vibration noise of the housing can be suppressed to reduce noise.

  Further, according to the present invention, since the dynamic vibration absorber is detachably provided on the outer wall of the housing, for example, a combination of the characteristics of the motor that is a driving source and the configuration of the driven side driven by the output shaft It becomes possible to selectively attach according to conditions.

  According to the present invention, the dynamic vibration absorber includes a weight having a predetermined mass, an elastic support portion that supports the weight so as to be displaceable in the vibration direction of the housing, and a suppression unit that suppresses the movement of the elastic support portion. Therefore, it is possible to set so as to suppress the resonance phenomenon at the natural frequency of the housing by changing the mass of the weight.

  In addition, according to the present invention, since the elastic support portion is made of a circular metal plate, a compact configuration can be achieved.

  In addition, according to the present invention, the bracket can be eliminated by integrally forming the elastic support portion that supports the weight so as to be displaceable in the vibration direction, so that the number of assembling steps to the housing can be reduced. This is advantageous when assembly work is performed in the process.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a front view showing Embodiment 1 of the speed increasing / decreasing gear according to the present invention. 2 is a side view of the speed reducer shown in FIG. FIG. 3 is a plan view of the speed increasing / decreasing device shown in FIG. As shown in FIGS. 1 to 3, the speed reducer 10 includes a housing 20, an input shaft 30 protruding from the rear portion of the housing 20, an output shaft 40 protruding from the front portion of the housing 20, and the interior of the housing 20. And an acceleration / deceleration mechanism (not shown) housed in the housing.

  Hereinafter, in the present embodiment, a case where the speed increasing / reducing gear 10 is used as a speed reducing device will be described. Further, in this embodiment, as the speed reduction mechanism (transmission mechanism), an eccentric oscillating type internally meshing planetary gear speed reducer that can set a high speed reduction ratio and has high durability and reliability is used. . It should be noted that a reduction mechanism other than the reduction gear, such as a parallel shaft type reduction gear mechanism that decelerates with a multi-stage gear set, or a simple planetary gear mechanism that engages with a sun gear and rotates and revolves to reduce the speed is provided inside the housing 20. The thing of the structure accommodated may be sufficient.

  The housing 20 is formed in a predetermined hollow shape by, for example, a casting or the like, and is in a resonance state when the vibration frequency generated by the operation of the internal speed reduction mechanism coincides with the natural frequency, so that vibration is suppressed. A vibration suppressing mechanism 50 is detachably provided.

  The housing 20 is configured by combining an input side housing 22, a main body housing 23, and an output side housing 24. It has been. A bearing (not shown) that supports the output shaft 40 is accommodated in the bearing portion 28 and has a stepped shape because the outer periphery has a small diameter. In the present embodiment, the vibration suppressing mechanism 50 is attached to the outer wall of the bearing portion 28 having the step shape, so that the vibration suppressing mechanism 50 does not protrude larger than the flange portion 26.

  The vibration suppression mechanism 50 includes a dynamic vibration absorber 60 and a pair of brackets 70 attached to the bearing portion 28. The pair of brackets 70 includes a mounting surface 72 to which the dynamic vibration absorber 60 is fixed, an arcuate portion 74 corresponding to the outer periphery of the bearing portion 28, and fixing portions 76 that protrude from both left and right ends thereof. The pair of brackets 70 are fastened by bolts 78 and nuts 79 between the fixing portions 76 facing each other.

  The housing 20 includes a flange portion 26 that houses the speed reduction mechanism, and a bearing portion 28 that houses an output shaft 40 that is smaller than the flange portion 26, and is a space defined by the flange portion 26 and the bearing portion 28 of the housing 20. The dynamic vibration absorber 60 is disposed on the side. Therefore, the dynamic vibration absorber 60 is provided above the bearing portion 28 serving as a concave portion of the housing 20 and is attached so as not to protrude greatly above the flange portion 26.

  Since the pair of brackets 70 are detachably fitted and fixed, for example, they are attached as necessary after the speed reducer 10 is installed. 1 to 3, the configuration in which the dynamic vibration absorber 60 is attached to the attachment surface 72 of the upper bracket 70 is shown. However, when the amplitude of vibration is large, the dynamic vibration absorber is also applied to the lower bracket 70. 60 may be attached. In this case, the two dynamic vibration absorbers 60 can be arranged at intervals of 180 degrees, and the vibration component in the Z direction can be efficiently absorbed.

  Further, since the outer periphery of the bearing portion 28 is circular, the mounting direction of the pair of brackets 70 can be changed to the circumferential direction. For example, the bracket 70 is rotated 90 degrees with respect to the position of FIG. Thus, the dynamic vibration absorber 60 is mounted in a direction to absorb the vibration component in the X direction. Alternatively, by rotating the bracket 70 by 45 degrees with respect to the position of FIG. 1, the dynamic vibration absorber 60 can absorb the vibration component of 45 degrees that is intermediate between the X direction and the Z direction by the dynamic vibration absorber 60. Become.

  FIG. 4 is an enlarged longitudinal sectional view showing the dynamic vibration absorber. As shown in FIG. 4, the dynamic vibration absorber 60 is provided on a mounting surface 72 formed on the upper surface of the bracket 70, so that the weight 62 having a predetermined mass and the weight 62 can be displaced in the vibration direction of the housing 20. It has a diaphragm (elastic support part) 64 to support, and a friction generating part (suppression means) 66 that suppresses the movement of the diaphragm 64.

  Further, the diaphragm 64 and the friction damper 66 are held inside the fixed portion 80 that protrudes upward from the mounting surface 72. Further, a through bolt 82 penetrating the center hole of the weight 62 downward is inserted in the center of the diaphragm 64 and the friction damper 66, and a sliding body 84 formed in a hollow cylindrical shape is formed at the tip of the through bolt 82. It is screwed.

  The inner periphery of the diaphragm 64 is sandwiched between the weight 62 and the sliding body 84 and operates so as to bend in the vertical direction along with the vertical movement of the weight 62. Further, since the diaphragm 64 is made of a metal plate that is elastically deformed in response to a load, it functions as a leaf spring that is deformed by the vertical movement of the weight 62.

  The sliding body 84 disposed below the diaphragm 64 operates integrally with the weight 62 and the diaphragm 64 and slides on the friction member 86 accommodated on the inner periphery of the friction generating portion 66 to generate a frictional force. Is granted. The friction member 86 is formed in a ring shape from a material having a large friction coefficient, and is composed of, for example, a rubber O-ring.

  The friction member 86 functions as a damper that absorbs vibration energy by generating a frictional force on the sliding body 84 when the sliding body 84 moves up and down to decelerate the operation of the weight 62.

  As described above, when vibration is generated in the housing 20, the dynamic vibration absorber 60 moves the weight 62 up and down in response to the vibration, whereby the diaphragm 64 is elastically deformed, and the sliding body 84 is caused to friction with the friction member 86. A force is applied to suppress vibration of the housing 20.

  Then, by selectively changing the mass of the weight 62 according to the vibration frequency and amplitude of the housing 20, the vibration of the housing 20 can be more effectively absorbed and the noise caused by the vibration noise can be suppressed to obtain a silent effect. it can. Further, by selecting the thickness dimension and material of the diaphragm 64 and selecting the friction coefficient of the friction member 86, it is possible to ensure quietness corresponding to the change in the vibration frequency of the housing 20.

  Further, the vibration suppression mechanism 50 according to the first embodiment only requires a small vertical dimension and a small number of parts, so that the thickness and size can be reduced, and the manufacturing cost is low. In addition, by preparing a state in which the dynamic vibration absorber 50 is mounted on the mounting surface 72 of the bracket 70 in advance, it is possible to significantly reduce the mounting time at the installation site. Therefore, since the dynamic vibration absorber 60 can be easily attached together with the bracket 70 even when the noise from the housing 20 is not a problem at the beginning of the installation of the speed reducer 10, It becomes possible to respond.

  In the first embodiment, the case where the speed increasing / reducing gear 10 is used as the speed reducing device has been described as an example. However, the output shaft 40 is used as the input shaft so that the rotation of the motor is input to the output shaft 40. By using the input shaft 30 as an output shaft, the speed reduction mechanism becomes a speed increasing mechanism and can be used as a speed increasing mechanism.

  Next, a modification of the first embodiment will be described. FIG. 5 is a front view showing a modification of the first embodiment. FIG. 6 is a side view showing a modification of the first embodiment. 5 and 6, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 5 and 6, the vibration suppression mechanism 150 according to the modification has brackets 70 and 170 fastened to the outer periphery of the bearing portion 28, and the bracket 170 absorbs vibrations in two different directions. Thus, two dynamic vibration absorbers 60 are provided. The two dynamic vibration absorbers 60 are for the X direction and the Z direction, respectively, and are attached to the attachment surfaces 172 and 174 of the bracket 170. Therefore, when vibration is generated in the housing 20, the vibration suppressing mechanism 150 can simultaneously absorb the vibration component in the X direction and the vibration component in the Z direction. Therefore, the vibration suppression mechanism 150 can further increase the silence of the speed reducer 10.

  In the vibration suppression mechanism 150, since the outer periphery of the bearing portion 28 of the housing 20 is circular, the mounting direction with respect to the bearing portion 28 can be changed to the circumferential direction. The brackets 70 and 170 are fastened between the fixing portions 76 and 176 facing each other by bolts 78 and nuts 79.

  Therefore, the mounting position of the vibration suppression mechanism 150 can be adjusted in the circumferential direction of the bearing portion 28 by loosening the bolt 78 and the nut 79. For example, when the mounting position of the bracket 170 is adjusted to rotate 45 degrees clockwise from the position shown in FIG. 5, the mounting direction of the two dynamic vibration absorbers 60 is changed to change the horizontal direction of the housing 20 ( It is possible to effectively absorb vibration components in directions of 45 degrees and 135 degrees with respect to (X direction).

  As described above, the vibration suppressing mechanism 150 can adjust the mounting direction of the two dynamic vibration absorbers 60 in an arbitrary direction according to the vibration characteristics generated by the speed increase / decrease 10. Even when the vibration direction of 20 changes, it is possible to ensure quietness by adjusting the mounting angle of the bracket 170 during the next maintenance.

  FIG. 7 is a front view showing the second embodiment. FIG. 8 is a side view of the second embodiment. 7 and 8, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 7 and 8, in the speed increasing / decreasing device 210 according to the second embodiment, the vibration suppression mechanism 250 is integrally provided in the housing 20. The vibration suppressing mechanism 250 includes a fixed dynamic vibration absorber 260 and is directly attached to the housing 20 in an assembly process at a factory, for example. That is, in the present embodiment, it is not necessary to use the brackets 70 and 170 as in the first embodiment, and accordingly, the number of parts can be reduced and the manufacturing cost can be reduced.

  FIG. 9 is an enlarged longitudinal sectional view showing the dynamic vibration absorber of the second embodiment. FIG. 10 is an enlarged side view showing the dynamic vibration absorber of the second embodiment. As shown in FIGS. 9 and 10, in the dynamic vibration absorber 260, since the diaphragm 270 is formed integrally with the housing 20, the diaphragm 270 is also processed when the housing 20 is processed. The friction damper 280 has a screw portion 281 that is inserted into a space 290 formed below the diaphragm 270 from the front opening and screwed into the screw hole 29 of the bearing portion 28. In addition, the friction damper 280 is provided with an engaging portion 282 with which a tool (such as a spanner) engages at an upper portion, and a friction member 86 is accommodated therein.

  Similar to the first embodiment, the diaphragm 270 has an inner peripheral edge sandwiched between the weight 62 and the sliding body 84 and operates to bend in the vertical direction along with the vertical movement of the weight 62.

  In addition, the sliding body 84 disposed below the diaphragm 270 operates integrally with the weight 62 and the diaphragm 270 and applies a frictional force by sliding the friction member 86 accommodated in the inner periphery of the friction damper 280. Is done.

  As described above, when vibration is generated in the housing 20, the dynamic vibration absorber 260 moves the weight 62 up and down in response to the vibration, so that the diaphragm 270 is elastically deformed, and the sliding body 84 is caused to friction with the friction member 86. A force is applied to suppress vibration of the housing 20.

  Then, by selectively changing the mass of the weight 62 according to the vibration frequency and amplitude of the housing 20, the vibration of the housing 20 can be more effectively absorbed and the noise caused by the vibration noise can be suppressed to obtain a silent effect. it can.

  Next, a modification of the second embodiment will be described. FIG. 11 is a front view showing a modification of the second embodiment. FIG. 12 is a side view showing a modification of the second embodiment.

  As shown in FIGS. 11 and 12, the speed reducer 210 is provided with a cover 300 that covers the dynamic vibration absorber 260 on the upper portion of the housing 20. The cover 300 is a dustproof cover for preventing dust from adhering to the dynamic vibration absorber 260, and functions as a protective cover for preventing damage from external contact and external force.

  The cover 300 is made of a rust-resistant metal such as stainless steel or a resin material that does not easily corrode, and includes a fan-shaped cover 302 that covers at least the end on the output shaft side, and an arc-shaped cover that covers the outer periphery of the dynamic vibration absorber 260. Part 304. Therefore, the cover 300 is integrated with the housing 20 by fastening the fan-shaped cover portion 302 to the output-side housing 24 with a plurality of screws 306 and fastening the arc-shaped cover portion 304 to the input-side housing 22 with bolts 308. .

  The cover 300 fastened to the housing 20 has a shape that does not protrude outward from the housing 20 and is integrated with the housing 20 in terms of design.

  In the above description, the configuration in which the dynamic vibration absorber is attached to the output shaft side housing 24 is described as an example. However, the configuration is not limited thereto, and for example, the dynamic vibration absorber may be attached to the input shaft side housing 22. Of course.

  In the above-described embodiment, the eccentric oscillating type intermeshing planetary gear speed reducer has been exemplified, but it goes without saying that the present invention can be applied to other types of speed reducers.

  In each of the above embodiments, the case where the motor is used as a speed reducer has been described. However, in the case where the rotation of the motor is input to the output shaft, the motor is used as a speed increaser. It is used as a speed reducer when the input shaft that transmits the rotation is on the side with a large reduction ratio, and is used as a speed increaser when the input shaft that transmits the rotation of the motor is on the side with a small reduction ratio.

It is a front view which shows Example 1 of the speed increase / decrease machine by this invention. FIG. 2 is a side view of the speed increasing / decreasing device shown in FIG. 1. It is a top view of the speed increase / decrease machine shown in FIG. It is a longitudinal cross-sectional view which expands and shows a dynamic vibration absorber. FIG. 10 is a front view showing a modification of the first embodiment. FIG. 6 is a side view showing a modification of the first embodiment. 6 is a front view showing Example 2. FIG. 6 is a side view of Example 2. FIG. It is a longitudinal cross-sectional view which expands and shows the dynamic vibration damper of Example 2. FIG. It is a side view which expands and shows the dynamic vibration damper of Example 2. FIG. FIG. 10 is a front view showing a modified example of the second embodiment. FIG. 10 is a side view showing a modified example of the second embodiment.

Explanation of symbols

10, 210 Booster / Decelerator 20 Housing 22 Input side housing 24 Output side housing 30 Input shaft 40 Output shaft 50, 150, 250 Vibration suppression mechanism 60, 260 Dynamic vibration absorber 62 Weight 64, 270 Diaphragm 66, 280 Friction damper 70, 170 Brackets 72, 172, 174 mounting surface 80 fixing part 84 sliding body 86 friction member 300 cover

Claims (8)

In a speed increasing / decreasing device having a housing and a transmission mechanism housed in the housing and decelerating or speeding up rotation of the input shaft and transmitting it to the output shaft,
A speed increasing / decreasing device characterized in that a dynamic vibration absorber is provided in the housing for absorbing vibration of the housing that is generated in accordance with the operation of the transmission mechanism.   The speed increasing / decreasing device according to claim 1, wherein the dynamic vibration absorber is detachably provided on an outer wall of the housing. The dynamic vibration absorber is
A weight having a predetermined mass;
An elastic support portion for supporting the weight so as to be displaceable in the vibration direction of the housing;
Suppressing means for suppressing the movement of the elastic support part;
The speed increasing / decreasing device according to claim 1 or 2, further comprising:   The speed increasing / decelerating device according to claim 3, wherein the elastic support portion is made of a metal plate that is elastically deformed according to a load.   The speed increasing / decreasing device according to claim 1, wherein the dynamic vibration absorber is provided integrally with an outer wall of the housing. The dynamic vibration absorber is
A weight having a predetermined mass;
An elastic support formed integrally with the housing and supporting the weight so as to be displaceable in a vibration direction;
Suppressing means for suppressing the movement of the elastic support part;
The speed increasing / decreasing device according to claim 5, comprising:   The speed increasing / decreasing device according to claim 3 or 6, wherein the suppressing means includes a friction member that applies a friction force by displacement of the elastic support portion. The housing is
A flange portion that accommodates the transmission mechanism, and a bearing portion that accommodates a smaller output shaft than the flange portion;
The speed increase / decrease device according to claim 1, wherein a dynamic vibration absorber is disposed in a space defined by the flange portion and the bearing portion of the housing.

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