Measuring and testing – Vibration – Sensing apparatus
Reexamination Certificate
1999-03-24
2001-07-10
Chapman, John E. (Department: 2356)
Measuring and testing
Vibration
Sensing apparatus
C073S514330, C073S514370, C073S660000
Reexamination Certificate
active
06257065
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for detecting drive line system imbalances, and more particularly to an optical vibration sensor which records the vibration experienced by a drive line component.
A drive shaft typically includes an elongated tubular member which is operatively coupled to the transmission and axle assembly through a pair of universal joints or other similar coupling disposed on either end of the shaft. Alternatively, the drive shaft may include two or more elongated tubular members which are connected together by a universal joint or some other similar coupling device and connected between the transmission and wheel assembly.
The individual components of the drive line system discussed above often include inherent or residual imbalances due to variations in manufacturing tolerances. While steps can be taken to balance the individual components, residual imbalances often still remain. It is further known to balance the drive line system prior to, and after, installation into the vehicle. Typically, such balancing is effective to practically eliminate objectionable vibration in the drive line system of a fully assembled vehicle. However, mechanical wear, residual imbalances, and road conditions may eventually lead to the disruption of the drive line balance. Vehicle drive line systems which become unbalanced are unacceptable as they produce drive line vibrations which could eventually lead to failure.
Accordingly, it is desirable to provide a vibration sensor which measures the quantity of vibration that the drive line component is exposed to and which can record the overall operation of a drive line under actual operational conditions.
SUMMARY OF THE INVENTION
The vibration sensor of the present invention is preferably fabricated using micro machining technology such that the sensor is preferably fabricated as an integrated circuit chip. Accordingly, the micro-machined vibration sensor can be readily located in many small inaccessible locations of a vehicle drive line.
The vibration sensor of the present invention generally includes a housing having a strain gage attached to the drive line component, and an actuator disposed within the housing. The sensor is preferably positioned such that it is minimally affected by radial acceleration, yet remains sensitive to longitudinal accelerations along the longitudinal axis of a drive line component.
In operation, the actuator exerts a force upon the strain gage proportional to acceleration experienced by the actuator. The actuator is preferably in contact with the strain gage by disposing the actuator between a pair of opposed strain gages. As the actuator is preferably a sphere, the contact locations are minimized in area to further reduce the friction between the actuator, strain gage, and the housing. This improves the vibration sensor sensitivity.
The controller then identifies the pressure exerted by the actuator on the strain gage. Control and identification can be provided by signal processing circuitry well known in the art of pressure measurement.
In another embodiment, the actuator is a pendulum attached to the housing by a pivot point having low friction bearings. The pivot point and low friction bearings, again reduces the effect of radial acceleration upon the longitudinal acceleration measurement.
A recording device is preferably in communication with the controller to record the pressure the actuator applies to the strain gage. By recording the pressure, the present invention provides an inexpensive diagnostic and maintenance system which can record the overall operation of a drive line under actual operational conditions. Additionally vibration trends can be determined and tracked to provide data to calculate the life of a drive line or the like.
Further, the controller identifies whether the vibration sensor experiences a predetermined acceleration and activates a warning device. In the preferred embodiment, the controller activates a transmitter, such as a radio frequency (RF) transmitter which sends a signal to a remote waining device such as a warning light.
REFERENCES:
patent: 3023627 (1962-03-01), Geyling
patent: 3478604 (1969-11-01), Evans
patent: 3828294 (1974-08-01), Baba et al.
patent: 4114453 (1978-09-01), Sandler
patent: 4348905 (1982-09-01), Nishimura et al.
patent: 4458536 (1984-07-01), Ahn et al.
patent: 5001933 (1991-03-01), Brand
patent: 5034729 (1991-07-01), Lundquist
patent: 5396223 (1995-03-01), Iwabuchi et al.
patent: 5415026 (1995-05-01), Ford
patent: 5610337 (1997-03-01), Nelson
patent: 5641904 (1997-06-01), Kopp et al.
patent: 5742235 (1998-04-01), Miché
Carlson & Gaskey & Olds
Chapman John E.
Meritor Heavy Systems, L.L.C.
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