Measuring and testing – Dynamometers – Responsive to force
Reexamination Certificate
2002-10-18
2004-08-10
Lefkowitz, Edward (Department: 2855)
Measuring and testing
Dynamometers
Responsive to force
Reexamination Certificate
active
06772648
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable.
BACKGROUND OF THE INVENTION
The present invention relates to the determination of bearing parameters, and more particularly, to a method and apparatus for determining bearing radial loads or bearing interference fits based on data sets which identify relationships among either the measured bearing radial loads or the interference fit, the measured bearing inner ring or bearing outer ring creep rate, and the measured bearing rotational speed.
Arrangements for measuring radial forces or loads applied to rolling element bearings such as ball bearings, cylindrical bearings, tapered bearings, and the like have found a wide use in machines for producing and treating textile fabrics, paper, and foils of various kinds where the material being transferred by means of a roller or other rotationally driven element must be maintained at or below a predetermined tension. Various designs have been utilized to measure these radial forces, including the use of conventional load sensing devices such as load cells, strain gages, and displacement sensors.
For example, U.S. Pat. No. 4,203,319 to Lechler for an “Apparatus For Measuring Bearing Forces” discloses an apparatus for the measuring of external forces by means of a preloaded rolling element bearing which is provided with at least two strain gauges which serve to measure the forces applied to the rolling element bearings. By placing the strain gauges in locations between the outer ring of the bearing and the housing within which the bearing is mounted, the apparatus of the '319 Lechler patent is capable of measuring external forces exerted on a roller bearing.
Alternative configurations of apparatus for measuring radial forces acting upon a bearing are set forth in U.S. Pat. No. 4,112,751 to Grünbaum and U.S. Pat. No. 4,281,539 to Keller. The measuring apparatus disclosed in these patents essentially comprise two concentric rings interconnected by a web of material. A rolling element bearing transmits the force to be measured to one of the rings, while the other ring is held in a fixed position. As the one ring moves in relation to the fixed ring, the web of material interconnected the two rings is deformed, and the deformation is measured electrically by means of a load cell, strain gage, or displacement sensor.
When bearing race creep occurs, in certain applications it could eventually result in bearing damage. It would be advantageous to develop a low cost, practical, and accurate method and apparatus for the determination of the interference fit or radial loads acting on a rolling element bearing structure from measured values such as the rotational speed and bearing race creep rate, whereby an expected operational life of the bearing and mounting component systems may be determined.
BRIEF SUMMARY OF THE INVENTION
Briefly stated, an embodiment of the present invention provides an apparatus and a method for determining the radial load on a bearing having inner and outer races, one of which rotates relative to the other. The rotating race is secured by an interference fit with its mounting component and experiences rotation or creep at an observable rate relative to the mounting component. Measurement of the angular velocity of the rotating race relative to the corresponding mounting component is utilized to determine the creep rate between the rotating race and the mounting component. The determined creep rate is compared with predetermined radial load data correlated with the interference fit precision between the rotating race and the mounting component to identify the actual radial load experienced by the bearing.
In an alternate embodiment of the present invention, the measured angular velocity and determined creep rate, together with the known interference fit of the bearing are utilized to generate a unique curve-fit representative of the radial load experienced by the bearing components.
In an alternate embodiment of the present invention, an apparatus and a method are provided for determining the interference fit of a bearing having inner and outer races, one of which rotates relative to the other. The rotating race is secured by an interference fit with its mounting component and experiences rotation or creep at an observable rate relative to the mounting component. Measurement of the angular velocity of the rotating race relative to the corresponding mounting component is utilized to determine the creep rate between the rotating race and the mounting component. The determined creep rate is compared with predetermined interference fit data correlated with the radial load to identify the actual interference fit between the rotating race and the mounting component of the bearing.
In an alternate embodiment of the present invention, an apparatus and a method is provided for determining the interference fit of a bearing having inner and outer races, one of which rotates relative to a mounting component. The rotating race is secured by an interference fit with its mounting component and experiences rotation or creep at an observable rate under a measured radial load relative to the mounting component. Measurement of the radial load, creep rate, and the angular velocity of the rotating race relative to the corresponding mounting component is utilized to determine a unique curve-fit representative of the interference fit between the rotating race and the mounting component.
An apparatus of the present invention for providing data utilized in determining the radial load on a rolling element bearing such as a ball bearing, cylindrical bearing, tapered bearing, spherical bearing, or the like, includes a first Hall effect sensor positioned relative to the rotating bearing race and a second Hall effect sensor positioned relative to the corresponding mounting component to which the rotating bearing race is secured by means of an interference fit of predetermined bearing fitting practice. Both the bearing race and the corresponding mounting component include one or more target elements positioned to generate signals in the Hall effect sensors as they are carried thereby during rotation of the respective components. A microcontroller or Digital Signal Processor (DSP) receives the signals from the Hall effect sensors for subsequent processing. A resulting bearing radial load determination is generated by the microcontroller or DSP for display on an associated display unit or sending by communicational buses.
An apparatus of the present invention for providing data utilized in determining the interference fit between a bearing race and a corresponding mounting component, includes one or more strain gauges or load cells positioned to measure the radial load on the bearing race. A first Hall effect sensor positioned relative to the rotating bearing race and a second Hall effect sensor positioned relative to the corresponding mounting component to which the rotating bearing race is secured. Both the bearing race and the corresponding mounting component include one or more target elements positioned to generate signals in the Hall effect sensors as they are carried thereby during rotation of the respective components. A microcontroller or Digital Signal Processor (DSP) receives the signals from the strain gauges or load cells, and from the Hall effect sensors for subsequent processing. A resulting bearing interference fit determination is generated by the microcontroller or DSP for display on an associated display unit or sending by communicational buses.
The foregoing and other objects, features, and advantages of the invention as well as presently preferred embodiments thereof will become more apparent from the reading of the following description in connection with the accompanying drawings.
REFERENCES:
patent: 4015468 (1977-04-01), Simon
patent: 4112751 (1978-09-01), Grunbaum
patent: 4203319 (1980-05-01), Lechler
patent: 4281539 (1981-08-01), Keller
patent: 5140849 (1992-08-01), Fujita et al.
patent: 5248939 (1993-09-01), Braue
Davis Octavia
Lefkowitz Edward
Polster Lieder Woodruff & Lucchesi
The Timken Company
LandOfFree
Method and apparatus for determining bearing parameters does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for determining bearing parameters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for determining bearing parameters will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3311232