Planetary gear transmission systems or components – Electric or magnetic drive or control
Reexamination Certificate
1999-10-01
2001-02-20
Estremsky, Sherry (Department: 3681)
Planetary gear transmission systems or components
Electric or magnetic drive or control
C475S339000, C105S001500, C105S157200
Reexamination Certificate
active
06190279
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to a power transmission system for rotating a driven shaft coupled to a work performing assembly. More specifically, the invention relates to a power transmission system for driving a working assembly from start-up through various slow speeds, and at top speed without stalling the drive motor. And a specific embodiment of the invention is directed to a power transmission system for a scale model train locomotive.
BACKGROUND OF THE INVENTION
Model railroad locomotives exist in various sizes. Serious model railroaders operate these locomotives in all scales from the smallest N gauge to the largest G gauge. A locomotive may have a length greater than one foot and a weight of several pounds in the larger scales. And larger models are often used in a sight-seeing park such as a zoo. Currently, the desire to have these model locomotives operate in the same fashion as full size locomotives is thwarted because of drive motor size limitations with respect to the various available model locomotives.
Of particular importance is the manner in which these locomotives operate from a standstill to acquire an equivalent scale operation of a full-size train. The model railroader is always looking for a more realistic looking operation of the model locomotive. But because of space limitations, the motors used to drive existing model locomotives, usually called “can” motors because they look like a small can, are very small and weak.
The known electric drive motors range from about ½ inch to about 1½ inches in diameter with a length from about 1 inch to about 1¾ inches. These small direct current (DC) electric motors have a power range from about 0.002 to about 0.009 horsepower with a rotational speed range for the rotatable power shaft of the motor in the range of about 7,000 to about 16,000 revolutions per minute (rpm). The locomotive motor power shaft is connected to a drive shaft that rotates a worm and worm gearset connected to rotate the locomotive drive wheels also known as drivers. The normal installation uses a 31:1 worm and worm gear ratio to produce one revolution of the drivers for 31 revolutions of the drive shaft to provide sufficient power once the motor is running. The problem with these existing locomotives, however, is that slow realistic starts and very low speed control are difficult to achieve without stalling the drive motor.
Attempts have been made to effect the noted desired results by using pulsating current to operate the electric motors and/or by using technological advances such as skewed armatures in the motor construction itself. Yet at slow operating speeds, the armature of the electric motor turns very slowly and is thus subject to stalling from any unexpected load increase or any slight bind in the locomotive drive mechanism. Moreover, operating these motors at very slow speeds under a load for more than short time periods may soon overheat the motor causing possible motor damage.
The known motors used to drive these locomotives require 1½ to 2 volts to start the motor running for rotating a driven shaft coupled to rotate the locomotive drivers. Known locomotive drivers will not rotate on track provided until there is enough power input to the worm and worm gearset to move currently available locomotives along the track. Problems often occur when increasing electric power to the DC motor to increase the rotational speed of the motor and drive shaft. The model railroad locomotive may give a lunging or uneven thrust movement and its motor may ultimately stall. Thus, it is extremely difficult to achieve the desired result of a realistic slow motion start without stalling the locomotive drive motor or without the locomotive producing a lunging or thrusting movement because of a lack of a continuous, adequate power supply to the locomotive drive wheels.
The mechanism of the present invention used to drive scale model locomotives would be modified in each of the other potential uses for the physical and mechanical characteristics of the particular item.
U.S. Pat. Nos. 4,234,164 and 4,721,083 show different systems for producing a stall preventative feature in the power transmission train for a motor. Neither of these prior art systems are operable to achieve the results achieved in the power transmission system of the current invention.
U.S. Pat. No. 4,676,121 shows a planetary gear mechanism used in conjunction with a flywheel for producing inertia moment of the flywheel during idling. This configuration, however, is not equivalent to the structure of the power transmission system disclosed herein.
PURPOSE OF THE INVENTION
The primary object of the present invention is to provide a power transmission system for a model train locomotive to enable its motor to start and continue running while the locomotive itself is not moving.
Another object of the invention is to incorporate a power transmission system between the existing motor and the worm gearset of a standard model railroad locomotive to eliminate the long standing problems of start-up motor stall and lunging movement during a slow, variable speed operation under load.
A further object of the invention is to provide a power transmission system usable in other settings such as in the common ⅜ths inch variable speed electric drill that has a normal rotational output of 1,500 rpm for the tool-holding mechanism and a cooling fan. By using the power transmission system between the electric drive motor of the drill and the driven shaft that rotates the tool holding mechanism, a more powerful and consistent rotating capability is achieved.
Still another object of the invention is to provide a power transmission system that is adaptable for driving units having much greater loads and larger drive motors including hydraulic motors, internal combustion engines, and larger battery driven motors used in land vehicles such as golf carts, motorcycles, and automobiles, for example.
A further object is to provide a power transmission combination in an apparatus that performs a desired operational function in response to a rotating drive shaft member wherein a motor power input shaft drives the drive shaft member of the apparatus.
SUMMARY OF THE INVENTION
The power transmission combination of the invention may be placed in any apparatus that performs a desired operational function in response to a rotating drive shaft member wherein motor means includes a rotatable power input shaft means for rotating the drive shaft member and motor control means regulates the rotational speed of the power input shaft means. The combination comprises driven output shaft means coupled to rotate the drive shaft member and flywheel means mounted to rotate on shaft means about a flywheel axis of rotation. Gear train means is connected to rotate with the power input shaft means for effecting rotation of the flywheel means about the flywheel axes of rotation for rotating the driven output shaft means when the motor means rotates the power input shaft means. The gear train means is effective to rotate the flywheel means when a load is applied to the driven output shaft means so that the motor means continues to operate smoothly without being adversely affected when the motor control means increases the rotational speed of the power input shaft means for rotating the driven output shaft means through the gear train means under an increased applied load.
The power transmission assembly of the invention may be retrofit into an operational mode linking its output shaft means to a drive shaft member for operating an apparatus that performs an operational function in response to motor means that rotates power input shaft means. The transmission assembly comprises means for mounting flywheel means to rotate on shaft means about a flywheel axis of rotation and means for coupling driven output shaft means to rotate the drive shaft member of the apparatus performing the desired operational function. Gear train means is effective for rotating the flywheel means about the f
Estremsky Sherry
Markva Neil F.
Pang Roger
LandOfFree
Power transmission system with a stall prevention feature does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Power transmission system with a stall prevention feature, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Power transmission system with a stall prevention feature will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2587956