Measuring and testing – Simulating operating condition – Marine
Reexamination Certificate
1996-02-15
2002-02-05
McCall, Eric S. (Department: 2855)
Measuring and testing
Simulating operating condition
Marine
Reexamination Certificate
active
06343504
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to transmission testers and methods of testing transmissions, especially rebuilt automatic transmissions for automobiles and trucks. More specifically, the invention is directed to transmission test apparatus to which an automatic transmission may be mounted, in driven relation to, in combination, a prime mover and a braking apparatus, for simulating driving conditions in a vehicle, and to novel braking apparatus.
BACKGROUND OF THE INVENTION
Automatic transmission test stands are generally known. Typical of such test stands is the test stand taught in, for example, U.S. Pat. No. 4,732,036 Weeder. Weeder teaches a test stand wherein the headstock, which receives the transmission thereon while the transmission is being tested, can move transverse to the tailstock shafts, as well as being able to move vertically. The prime mover internal combustion engine also can move transversely as well as vertically, but on supports separate from the headstock supports.
U.S. Pat. No. 4,356,724 Ayoub et al teaches using an electric motor as the prime mover, as does U.S. Pat. No. 5,142,903 Mizushina et al. Ayoub et al show the electric motor fixedly secured to a support remote from the headstock support. Mizushina et al do not show the mounting support for the electric motor. Neither reference teaches any electronic apparatus for conditioning the electricity supplied to the electric motor.
In all the references known to the inventor, only flywheel-type inertia devices are taught as load devices, for applying a load to the engine during the test procedure.
No reference known to the inventor provides a single test stand for testing automatic transmissions wherein the headstock is mounted to the main frame with sufficient freedom of movement to mount and test all of (1) rear wheel drive transmissions, (2) transverse mounted front wheel drive transmissions, and (3) longitudinally mounted front wheel drive transmissions.
No reference teaches or suggests mounting an electric motor as the prime mover to the same support that mounts the headstock which receives the transmission. Neither does any reference teach using electric brakes.
It is an object of this invention to provide an improved transmission tester, and methods of use, wherein an electric motor is provided as the prime mover, fixedly secured for adjusting movement relative to a braking unit, in combination with the headstock and corresponding transmission secured to the headstock.
It is another object to provide a transmission tester, and methods of use, wherein an electric motor is provided as the prime mover, and is adapted to temporarily suspend acceleration when the transmission shifts gears.
It is a further object to provide a transmission tester wherein the headstock can pivot about a vertical axis, to thereby receive a longitudinally mounted transaxle, as well as to receive transversely mounted transaxles and rear wheel drive transmissions.
It is another object to provide a load device, for providing an active load simulating the deadweight load of a range of vehicle weights.
It is a more specific object to provide a load device adapted to apply a mechanical resistance load within a range of available torque values, including selecting one or more torque values as part of testing each transmission.
It is a still more specific object to provide an eddy current brake as an active load device, for applying resistance torque to the transmission while the transmission is being tested.
SUMMARY OF THE DISCLOSURE
The invention generally comprehends improvements in transmission testing apparatus, including use of eddy current brakes, pivoting the headstock about a substantially vertical axis, and providing enhanced electrical controls that allow use of an electric motor prime mover while simulating the loading characteristics of an internal combustion engine.
Some of the objects are obtained in a first family of embodiments comprehending a transmission tester for testing vehicular transmissions, the transmission tester comprising a main frame; a prime mover, for providing driving energy to a transmission to be tested; a headstock plate adapted to receive thereon a transmission to be tested, the headstock plate being supported from the main frame by a support, for pivoting the headstock plate about a first axis; and braking apparatus, supported from the main frame, the braking apparatus including a shaft journalled for rotation about a second axis substantially perpendicular to the first axis, and extending generally toward the headstock plate, for engaging an output shaft of the transmission to be tested, and for thereby applying braking energy to the transmission.
In preferred embodiments, the first axis is substantially vertical and the second axis is substantially horizontal. The support comprises a headstock frame, supported from the main frame, between the main frame and the headstock plate, the headstock frame being mounted for pivotation about the first axis, thereby to pivot the headstock plate about the first axis, with the headstock plate being adapted to face in a first direction along an imaginary line extending toward the brake unit, and to pivot about the first axis to thereby face in a second direction transverse to the imaginary line extending toward the brake unit. Accordingly, the headstock plate can pivot about an included angle, between the first and second directions, of at least about 90 degrees.
The transmission tester preferably has opposing first and second ends, and a length therebetween, the prime mover comprising an electric motor, mounted to the headstock frame, the headstock frame, with the electric motor thereon, being supported from the main frame for movement both of the combination of the headstock frame and the electric motor in a direction having a vertical component, and of the combination of the headstock frame and the electric motor in a direction having a transverse horizontal component relative to the length of the transmission tester.
In preferred embodiments, the prime mover comprises an electric motor, mounted for pivotation with respect to the first axis, and includes an inverter adapted to vary the speed of the electric motor, and to temporarily suspend acceleration of the speed of the electric motor when a transmission being tested shifts gears.
In highly preferred embodiments, the prime mover comprises an electric motor mounted to the headstock frame, and the headstock plate is mounted to the headstock frame, for pivoting both the prime mover and the headstock plate, in combination, with respect to the first axis.
The braking apparatus preferably comprises an eddy current brake.
In a second family of embodiments, the invention comprehends a transmission tester for testing vehicular transmissions, the transmission tester comprising a main frame; a prime mover, for providing driving energy to a transmission to be tested; a headstock plate, supported from the main frame, for receiving thereon transmissions to be tested; and braking apparatus, supported from the main frame, the braking apparatus comprising a connecting shaft journalled for rotation about a first axis, and for applying braking energy to a transmission to be tested, the braking apparatus being adapted to dynamically apply a resistance torque which varies within a range of vehicle deadweight loads, and braking loads, simulating a correspondingly varying range of vehicle deadweight loads, and braking loads, preferably comprising an eddy current brake.
In preferred transmission testers of the invention, the eddy current brake has a longitudinal axis defining a length, a shaft extending along the longitudinal length of the brake, a stator, including at least first, second, third, and fourth electromagnetic stator coils disposed in side-by-side relationship with each other about the shaft, and an end pole associated with each electromagnetic stator coil, and a rotor secured to the shaft, for rotation with the shaft and adjacent the end pole, with a gap between the rotor and the end po
Hicklin Engineering, L.C.
McCall Eric S.
Zarley McKee Thomte, Voorhees & Sease PLC
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