Bearings – Rotary bearing – Antifriction bearing
Reexamination Certificate
1999-08-04
2001-07-24
Hannon, Thomas R. (Department: 3682)
Bearings
Rotary bearing
Antifriction bearing
Reexamination Certificate
active
06264370
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a bearing, and more particularly to isolating a bearing to prevent transmitted vibrations.
A gearbox or housing provides a mounting point for multiple shaft mounted intermeshing gears. Each shaft is typically mounted through the housing and retained at one or both ends by a bearing. The bearings are fitted into an opening in the housing and supports an end of the shaft. The shaft is rigidly mounted to maintain the shafts rotational centerlines which allows the shaft and gears to rotate at high speed within the housing.
As the shafts are rotated at high speed, any minor variations in the intermeshing gear teeth create vibration. Some of this vibration takes the form of sound energy, i.e. noise, which travels along a transmission path. The vibrations are transmitted along the transmission path through the mounted shaft, into the bearings, and into the housing. The vibration is further amplified by the housing and radiated to the environment. This noise and vibration is both undesirable and can be subject to regulatory rules.
It is known to manufacture the gear teeth to very tight tolerances in an attempt to minimize vibrations. It is further known to dampen the vibrations with elastomeric bearings. However, the former reaches the limits of a machining process and the later can interfere with maintaining the rotational centerlines of the shafts.
Accordingly, it is desirable to break the transmission path to reduce the transmitted noise while maintaining a rigid structure for supporting the high speed rotation of the gear shafts.
SUMMARY OF THE INVENTION
An isolator according to the present invention breaks the transmission path of noise and vibration while maintaining a rigid structure to support the high speed rotation of a shaft.
The isolator is preferably manufactured as a ring which fits within an opening of a housing. The bearing is inserted into the isolator with the isolator being sandwiched between the bearing and the housing. The shafts can thus be rotated at high speed as the shaft centerlines and resulting gear alignment is maintained by the isolator's rigid mounting of the bearing.
The isolator is preferably manufactured from a material different than the housing material. The preferred material for the isolator being a laminate such as two sheets of metallic material having a non-metallic material sandwiched therebetween. The dissimilar materials of the laminate breaks the vibration transmission path. Transmission of vibrations through the rotating shaft is decoupled from their transmission path by the dissimilar materials of the isolator. Further, as the isolator and housing materials are different. The vibration path is also disrupted. Accordingly, noise is substantially prevented from reaching and being amplified by the housing. This substantially reduces the resulting noise and vibration radiated to the environment.
Another embodiment of the present invention provides a bearing assembly having a noise isolating outer member. By manufacturing the outer member of a laminate, or other rigid vibration isolating material, the outer member itself breaks the transmission path of vibrations. The outer member therefore integrates the isolator as described above directly into the bearing assembly simplifying assembly and reducing cost.
REFERENCES:
patent: 3093427 (1963-06-01), Vasta
patent: 3528712 (1970-09-01), Vacca et al.
patent: 3554619 (1971-01-01), Irwin
patent: 3672734 (1972-06-01), Bando
patent: 4229055 (1980-10-01), Olschewski et al.
patent: 5033875 (1991-07-01), Moulinet
patent: 5044784 (1991-09-01), Lisowsky
patent: 5062721 (1991-11-01), Chiba
patent: 5316274 (1994-05-01), Rudolph
patent: 5359842 (1994-11-01), Braxmeier et al.
patent: 5781373 (1998-07-01), Larson et al.
patent: 5816712 (1998-10-01), Brown et al.
patent: 5902050 (1999-05-01), Balczun et al.
Bell Dale
Brissette Ronald N.
Keeney Christopher S.
Kramer Dennis A.
McKenzie Jack R.
Carlson Gaskey & Olds P.C.
Hannon Thomas R.
Meritor Heavy Vehicle Systems LLC
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