Planetary gear transmission systems or components – Input from independent power sources – Including electric motor input
Reexamination Certificate
2002-07-24
2004-06-15
Ho, Ha (Department: 3681)
Planetary gear transmission systems or components
Input from independent power sources
Including electric motor input
C475S332000, C475S151000, C180S065600, C180S065700
Reexamination Certificate
active
06749532
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an electric drive for vehicles.
2. Discussion of Background Information
U.S. Pat. No. 516,917 A describes an electric drive that is used for driving two wheels independently, whereby one wheel is connected to the field winding so as to be stationary in relation to the winding, and the other wheel is connected to the rotor via a differential gear. In order to achieve an equal torque on both wheels the differential gear must, with the field winding and rotor running at the same speed, effect a reverse in the direction of rotation of the rotor only, without changing the speed. This is the case in the embodiments shown, on the one hand as a differential gear ring similar to the arrangement in known axle differentials, on the other hand as a spur pinion-planetary gear with the same function.
Furthermore, U.S. Pat. No. 613,894 describes a dynamo and electric drive for vehicles. In this embodiment with two electric components capable of coaxial rotation, the two components are connected to each other by a gear unit with high speed reducing ratio, and to a stationary part. In one embodiment, it is suggested that the housing of the rotating field winding should be connected to a drive wheel of the vehicle so as to be stationary in relation to the wheel. In a further embodiment, the internal shaft is to be used as a drive for slow-running machines.
Furthermore, a device with a rotating field winding is known, whereby current is supplied to the field winding via slip rings. The equally rotating rotor drives the housing of the field winding via a planetary gear with a high speed-increasing ratio. As in U.S. Pat. No. 613,894 A, this unit is used preferably for slow-running machines, for example as a drum drive for winches, whereby the entire drive has room within the drum.
A drive train for an electric vehicle is also described in U.S. Pat. No. 5,845,732 A. Thereby, one drive shaft is connected to a rotor that is arranged coaxially with the wheel shafts, whereby the rotor is mounted on a hollow shaft and drives the sun gear of a planetary gear. The web of this gear is connected to a wheel shaft that runs through the hollow rotor shaft. The ring gear of the gear is connected to the web of another planetary gear that is arranged coaxially with the rotor shaft. This gear has to effect a torque reversal so that the second wheel shaft, to which it is connected, rotates in the same direction as the first wheel shaft. The disadvantage of this embodiment is the need for a hollow shaft to accommodate the rotor.
U.S. Pat. No. 5,487,438 and EP 0 587 120 A3 describe a drive system for an electric vehicle. Within the scope of this drive system, an axle drive is shown in which the field winding, which is mounted so as to be capable of rotation and which is supplied via slip rings, is connected to the pinion of a gear unit. This pinion engages with a ring gear which in turn is connected to one of the wheel shafts so as to be stationary in relation to the shaft. In this gear unit, the pinion and the ring gear rotate in the same direction. The rotor, which is also mounted so as to be capable of rotation, drives a spur pinion that engages with another spur pinion that is connected to the other wheel shaft. This gear unit effects rotation of the wheel shaft in the opposite direction in relation to rotation of the rotor. The function of a differential gear is thus provided. With a suitable choice of gear wheel diameters, the wheel shafts can be aligned. The disadvantage of this embodiment is the fact that the field winding and the rotor rotate around an additional axle parallel to the wheel shafts, thus increasing the costs of construction of the housing. Furthermore, the intended high speed-increasing ratios require a large diameter for the ring gear of the gear unit, which reduces the ground clearance of vehicles with such an axle to a level that is not permissible.
U.S. Pat. No. 5,804,935 describes a drive system for electric vehicles.
This drive system is intended for vehicles with two driven axles, whereby a field winding that is mounted so as to be capable of rotation drives one wheel axle. With suitable devices, this drive train can be interrupted and the field winding can be fixed to the vehicle while the drive axle runs freely. Furthermore, a rotor is provided that drives the other drive axle. The current for the rotating field winding is provided via slip rings. The rotary movement of the rotor or field winding is transmitted directly to the connecting shaft to the drive axles. Under the condition that the rotor has the same rpm with reference to the stator, it is possible with the help of this device, with a fixed rotor and driving only one wheel axle, to achieve twice the driving speed as when driving both axles. In addition to the suitability of such a drive device only for vehicles with two driven wheel axles, a reduction gear must also be provided for each wheel axle in order to achieve a reasonable embodiment in terms of construction.
GB 2 008 862 A describes a double rotor with friction brakes.
A device is described in which both the field winding and the rotor are independently mounted on a joint axle so as to be capable of rotation and which can be fixed by means of friction brakes. Current is transmitted via slip rings. The rotational movement of the rotor and the field winding are superimposed in a suitable planetary gear unit. Downstream from this unit, there is a reduction gear for driving primarily a winch drum. By arresting the rotor or field windings, great differences in the rpm of the winch drum can be achieved, thus improving the handling of the relevant hoisting device or of a machine with similar specifications.
Furthermore, GB 2 254 965 A describes a gear system for vehicles driven by an electric motor. A device is proposed in which both the rotor and the field winding of a direct current unit are mounted on a mutual axle so as to be capable of rotation. Thereby, the rotor shaft is mounted on the vehicle so as to be capable of rotation at one end, and in the rotating housing of the field winding at the other end. The rotating housing of the field winding has a shaft stump at one end that is mounted on the vehicle. At the other end, the housing is mounted on the rotor shaft. The operating current is transmitted by slip rings that are mounted on the outer diameter of the housing of the field winding. The rotor has a collector that is supplied via rotating brushes connected to the housing.
U.S. Pat. No. 4,130,172 A describes an electric vehicle. In this disclosure, an electric motor drive system is described whereby the rotor and the field winding are arranged on a common axle so as to be able to rotate, whereby the direction of rotation of one of the output shafts is reversed with reference to the rotor movement by a bevel gear. The other output shaft is fixed rigidly to the rotation of the field winding. Since the described embodiment does not perform a reduction in rpm of the output shafts with reference to rotor and field coil, the drive wheels of the vehicle must be connected to the respective output shafts by means of a belt drive.
AT 405 924 B describes an electric drive for vehicles. This disclosure shows that the opposite direction of movement of rotor and field winding can be reduced to the wheel rpm either in the same or in opposite directions with a suitable planetary gear device, thus fulfilling the function of a gear drive with differential function. With the described gear units, rotor, field winding and wheel shafts can be arranged on one axis of rotation.
An axle drive for a vehicle is also known, whereby the rotor and the field winding are mounted so as to be capable of rotation and drive one wheel each. Both the main and the excitation current are supplied to the moving motor parts via an appropriately arranged slip ring transmission device. The necessary reduction to the rpm of the drive wheels is achieved with a two-step spur pinion unit for both the rotor and the field winding. An
Greenblum & Bernstein P.L.C.
Ho Ha
LandOfFree
Electric drive for a vehicle does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electric drive for a vehicle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electric drive for a vehicle will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3366252