JP2007155035A - Gear device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear device for reducing noises during non-resonance while suppressing an increase of noises at a difficult-to-avoid resonance point, which are generated in variable speed operation. <P>SOLUTION: The gear device comprises a small gear 2, a large gear 3 gearing with the small gear, a gear box 19 storing the small gear and the large gear, and a cartridge 21 journaling the small gear and mounted on the gear box. A dynamic vibration absorber consists of a damper 15 as a spring means and a damping means, and an additional mass 14. It is provided on the cartridge in the direction perpendicular to the gear shaft of the small gear and in the direction of vibrating force operating on the cartridge. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gear device, and more particularly, to a gear device suitable for reducing vibration noise of a pump bevel gear device such as a bevel gear or a spiral bevel gear.

  Industrial bevel gears with relatively large capacities are often used to drive pump equipment such as water supply and drainage facilities, but there are significant restrictions on noise generated by equipment such as when there is a residential area nearby. Exists. Usually, in order to reduce the radiated sound of the gear unit, methods such as improvement of gear accuracy and installation of a sound insulation cover are taken. Have difficulty.

  On the other hand, pump devices capable of variable speed operation using gas turbine prime movers, fluid couplings, etc. are becoming widespread, but the natural frequency of the gear unit and the excitation frequency resonate to increase resonance. May be a problem. In addition, since the transmission power of the gear device tends to increase with an increase in size of the pump device, the demand for reducing the noise of the gear device has become stronger.

  For example, as disclosed in Japanese Patent Application Laid-Open No. 2004-162754, a structure is known in which a weight member is provided on the surface of the gear box to reduce the natural frequency and avoid resonance of the gear box. It has been. Here, by exchanging this weight, the natural frequency of the gearbox can be adjusted to cope with various gearboxes and operating conditions.

JP 2004-162754 A

  However, simply avoiding gear box resonance at a specific frequency may cause a sudden increase in noise near the resonance point that could not be avoided when the gear unit was made variable speed using a gas turbine prime mover or fluid coupling. is there. In addition, the ability to attenuate so-called solid-propagating vibrations, which are generated by gear meshing and propagate from the gear shaft to the gear box surface via the bearing, is low. Noise reduction is not possible.

  An object of the present invention is to provide a gear device that suppresses an increase in noise at a resonance point that is difficult to avoid during variable speed operation, and that can reduce noise even during non-resonance.

(1) In order to achieve the above object, the present invention provides a small gear, a large gear meshing with the small gear, a gear box that houses the small gear and the large gear, and a shaft that supports the small gear. A pump bevel gear device having a cartridge attached to the gear box, the pump bevel gear device being in a direction orthogonal to a gear shaft of the small gear and in a direction in which an excitation force acts on the cartridge. And a dynamic vibration absorber having an additional mass provided via spring means and damping means.
With this configuration, an increase in noise at a resonance point that is difficult to avoid that occurs during variable speed operation can be suppressed, and noise can be reduced even during non-resonance.

  (2) In the above (1), preferably, the two additional masses are provided at positions that are substantially 180 degrees opposite to the small gear shaft, and are connected to each other so that both vibrate in the same phase. .

  (3) In the above (1), preferably, an angle formed by a leg of a perpendicular line dropped from the center of gravity of the additional mass to the center line of the small gear shaft and the center line of the large gear shaft is 20 degrees to 70 degrees. Degree.

  (4) In the above (1), preferably, a plurality of the additional masses are provided along the center line of the small gear shaft.

  (5) In the above (4), preferably, the additional mass is an outer peripheral portion of the cartridge and a translational additional mass provided in the vicinity of the center of gravity of the mass of the small gear shaft and the cartridge, And an additional mass for pitching provided at a position away from the center of gravity in the axial direction.

  (6) In the above (1), preferably, a vibration damping means made of a vibration damping material inserted in a joint portion between the gear box and the cartridge is provided.

  According to the present invention, an increase in noise at a resonance point which is difficult to avoid during variable speed operation can be suppressed, and noise can be reduced even during non-resonance.

Hereinafter, the structure of the gear apparatus by one Embodiment of this invention is demonstrated using FIGS. 1-3.
Initially, the whole structure of the gear apparatus by this embodiment is demonstrated using FIG.1 and FIG.2.
FIG. 1 is a side sectional view showing the overall configuration of a gear device according to an embodiment of the present invention. FIG. 2 is a front view showing the overall configuration of the gear device according to the embodiment of the present invention.

  The small gear shaft 1 and the small gear 2 are integrally formed, and are rotatably supported with respect to the cartridge 21 by small gear bearings 5 and 6. The small gear 2 meshes with a large gear 3 provided coaxially with the large gear shaft 4. The large gear shaft 4 is supported by the large gear bearings 7 and 8 so as to be rotatable in the radial direction, and is supported by the thrust bearing 9 so as to be freely rotatable in the axial direction. The gear box 19 holds the large gear bearings 6 and 7 and the thrust bearing 9 and is coupled to the cartridge 21 via the vibration damping material 31 to maintain the meshing of the gears. As the damping material 31, for example, a damping alloy is used. The upper lid 20 is attached to the gear box 19 and supports the large gear bearing 7. A thrust bearing cover 24 that covers the end of the large gear shaft 4 is installed on the upper portion of the upper lid 20.

  The lubricating oil supplied to the gear pair and the bearing is collected and pressurized by the pump device 10 inside the gear box 19 and flows into the radiator 16 through the pump discharge pipe 11 and the radiator inlet pipe 12. The radiator 16 is arranged at a position where the wind from the fan 22 provided coaxially with the small gear shaft 1 hits, and cools the lubricating oil passing through the inside. Thereafter, the lubricating oil is supplied again into the gear box through the radiator discharge pipe 17 and the oil supply pipe 18. The outer periphery of the fan 22 is covered with a fan cover 23.

  On the outer periphery of the cartridge 21, additional masses 14 a and 14 b are provided via dampers 15 and an additional mass frame 13 at positions substantially orthogonal to the small gear shaft 1. Since the additional masses 14a and 14b are located at positions that oppose each other at approximately 180 degrees and are connected to each other, they vibrate in the same phase when the cartridge vibrates. The damper 15 is made of a material having a damping function such as a vibration-proof rubber, and the spring constant can be controlled by adjusting the hardness of the rubber. By arranging the damper 15, the additional mass frame 13, and the additional masses 14 a and 14 b as described above, these constitute a dynamic vibration absorber for the cartridge 21. The damper 15 functions as a spring means and a damping means. The mounting direction of the dynamic vibration absorber is preferably a position orthogonal to the small gear shaft 1. Even if the position deviates by about ± 10 degrees from the position orthogonal to the small gear shaft 1, the effect of reducing the vibration noise is not significantly impaired.

  When the small gear shaft 1 is rotated by a prime mover such as a motor, the coaxial small gear 2, the large gear 3 that meshes with the small gear shaft 2, and the large gear shaft 4 that is coaxial with the small gear 2 rotate to transmit power to the output side. At this time, the torque variation of the meshing cycle occurs in the small gear shaft 1 and the large gear shaft 4 due to errors due to processing and assembly of the gear pair, and the variation of the tooth spring constant associated with the meshing. This torque fluctuation is converted into a translational force at the gear meshing portion and propagates from the gear shaft to the bearing, the cartridge 21 and the gear box 19 to generate gear noise.

  Also, if the gear rotation speed is changed using a variable speed prime mover or a fluid coupling, the gear meshing frequency will change, but if this frequency matches the natural frequency of the gear unit, it will resonate and generate noise. Will increase.

Here, the direction in which the excitation force acts on the cartridge 21 in the gear device according to the present embodiment will be described with reference to FIG.
FIG. 3 is an explanatory diagram of the direction in which the excitation force acts on the cartridge in the gear device according to the embodiment of the present invention. 1 and 2 indicate the same parts.

  As shown in FIG. 3, the torque fluctuation of the meshing cycle generated in the small gear shaft 1 and the large gear shaft 4 is applied with the excitation force F on the cartridge 21, and as a result, the cartridge vibrates in a specific direction. The direction of this vibration forms an angle θ with respect to the center line of the large gear shaft 4 when viewed from the shaft end side of the small gear shaft 1. In many cases, the angle θ is approximately 20 to 70 degrees.

  In the present embodiment, for the natural frequency that is difficult to avoid in the operating speed range, the frequency at which the dynamic vibration absorber acts is adjusted by adjusting the spring constant of the damper 15 and the mass of the additional mass 14. Noise is reduced by roughly matching the frequency.

  Further, the direction in which the dynamic vibration absorber acts is the direction in which the excitation force F acts when viewed from the shaft end side of the small gear shaft 1, so that noise based on torque fluctuation can also be reduced. The direction in which the dynamic vibration absorber acts, that is, the mounting angle of the dynamic vibration absorber is about an angle θ with respect to the center line of the large gear shaft 4. Although the direction in which the excitation force F acts and the direction in which the dynamic vibration absorber acts are preferably coincident, for example, even if they are deviated by about ± 10 degrees, the noise reduction effect is not significantly impaired.

  In the present embodiment, with the configuration as described above, even if there is a natural frequency that is difficult to avoid in the operating speed range of the gear device, the vibration amplitude is reduced by the dynamic vibration absorber, and noise can be reduced. it can. Further, even during non-resonance, the vibration propagated to the cartridge 21 is attenuated by the vibration damping material 31 inserted between the cartridge 21 and the gear box 19, so that noise can be reduced compared to the conventional model. .

Next, the configuration of a gear device according to another embodiment of the present invention will be described with reference to FIG. The overall configuration of the gear device according to the present embodiment is the same as that shown in FIG.
FIG. 4 is a side cross-sectional view showing a main configuration of a gear device according to another embodiment of the present invention. 1 and 2 indicate the same parts.

  In this embodiment, in order to reduce translational vibration of the cartridge 21 around the outer periphery of the cartridge 21 and the center of mass of the mass of the small gear shaft 1 and the cartridge 21, the translation additional mass 27 is interposed via the translation damper 28. Attached. Furthermore, in order to reduce pitching vibration (vibration in which the vicinity of the center of gravity is a node and the vicinity of the shaft end is an antinode) at a position away from the center of gravity in the axial direction, an additional mass 29 for pitching is attached via a pitching damper 30. is there. Other configurations are the same as those shown in FIGS.

  The natural frequency of the shaft system of the gear device varies depending on the mass of the rotating body, the moment of inertia, the bending torsional rigidity of the shaft, the shaft support rigidity, and the like, and there are various vibration modes that appear in the operating speed range. Since the dynamic vibration absorber has an effect of suppressing individual vibration modes due to resonance, when a plurality of vibration modes appear, a dynamic vibration absorber including a translational additional mass 27 for translational vibration and a translational damper 28, and pitching By providing the dynamic vibration absorber composed of the additional mass 29 for pitching and the damper 30 for pitching, it is possible to reduce translational vibration and vibration with respect to pitching, thereby reducing noise.

  In the present embodiment, by adopting the above-described configuration, in a variable speed gear device using a gas turbine prime mover, a fluid coupling, or the like, even when a plurality of vibration modes appear in the operating speed range, each vibration mode It is possible to suppress an increase in vibration noise due to resonance by providing a dynamic vibration absorber corresponding to the above.

  In addition, although each above-mentioned embodiment was an air-cooled gear apparatus which has a radiator, even if it is a water-cooled gear apparatus which does not have a radiator, it can be set as the same structure. In addition, the frame can be omitted for attaching the additional mass to the cartridge, and it goes without saying that the number and the axial position of the additional mass can be arbitrarily determined.

As described above, according to the present invention, the dynamic vibration absorber functions in the vicinity of the resonance point that is difficult to avoid, and the cartridge vibration is reduced, so that the gear box vibration is also reduced and noise can be reduced. . Further, even during non-resonance, the vibration propagated from the small gear shaft to the cartridge is attenuated by the damping material between the gear box and the cartridge, and the gear box vibration is reduced and noise is reduced.

It is side surface sectional drawing which shows the whole structure of the gear apparatus by one Embodiment of this invention. It is a front view showing the whole gear device composition by one embodiment of the present invention. It is explanatory drawing of the direction where the exciting force with respect to the cartridge in the gear apparatus by one Embodiment of this invention acts. It is side surface sectional drawing which shows the principal part structure of the gear apparatus by other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Small gear shaft 2 ... Small gear 3 ... Large gear 4 ... Large gear shafts 5, 6 ... Small gear bearings 7, 8 ... Large gear bearing 9 ... Thrust bearing 10 ... Pump device 11 ... Pump discharge piping 12 ... Radiator inlet piping 13 ... Additional mass frame 14 ... Additional mass 15 ... Damper 16 ... Radiator 17 ... Radiator discharge pipe 18 ... Oil supply pipe 19 ... Gear box 20 ... Upper lid 21 ... Cartridge 22 ... Fan 23 ... Fan cover 24 ... Thrust bearing cover 27 ... For translation Additional mass 28 ... Translation damper 29 ... Pitching additional mass 30 ... Pitching damper 31 ... Damping material

Claims (6)

A bevel gear device for a pump having a small gear, a large gear meshing with the small gear, a gear box that houses the small gear and the large gear, and a cartridge that pivotally supports the small gear and is attached to the gear box. Because
Provided on the cartridge in a direction perpendicular to the gear axis of the small gear and in a direction in which an excitation force acts on the cartridge;
A gear device comprising a dynamic vibration absorber made of an additional mass provided via a spring means and a damping means. The gear device according to claim 1, wherein
Two additional masses are provided at positions that are approximately 180 degrees opposite to the small gear shaft, and are connected to each other so that they vibrate in the same phase. The gear device according to claim 1, wherein
An angle formed by a leg of a perpendicular line drawn from the center of gravity of the additional mass to the center line of the small gear shaft and a center line of the large gear shaft is 20 degrees to 70 degrees. The gear device according to claim 1, wherein
A gear device, wherein a plurality of the additional masses are provided along a center line of the small gear shaft. The gear device according to claim 4,
The additional mass is a translational additional mass provided on the outer periphery of the cartridge and in the vicinity of the center of gravity of the mass of the small gear shaft and the cartridge.
A gear device comprising: an additional mass for pitching provided at a position away from the center of gravity in the axial direction. The gear device according to claim 1, further comprising:
A gear device comprising vibration damping means made of a vibration damping material inserted into a joint between the gear box and the cartridge.

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