Invention relating to electric drive

Abstract

Electric drive for transmitting the torques of at least two electric drive means via a gear box to an output shaft (A10-5), wherein the gear box has a partial gear box for each electric drive means and each partial gear box is coupled to the corresponding electric drive means via a corresponding input channel, wherein the partial gear boxes are designed and arranged to interact with one another and with the common output shaft (A10-5) in such a way that interruptions in the torque output of the output shaft (A10-5) are avoided during gear shifting operations of one or the other partial gear box, characterized in that a gear wheel (A11-2) has openings and a shift sleeve (A11-5.2) is designed such that it moves through these openings in order to produce positive-locking connections with two further gear wheel pairs (A11-2, A11-3) on both sides of the gear wheel (A11-2).

Description

The present invention relates to a new electric drive and to a method for controlling the drive, so that a gear step change with a transitionless progression of the torque at the output shaft is made possible in the case of purely electric or substantially electric drives, wherein the gear of the electric drive has one subtransmission per electric drive means and each subtransmission is coupled to the corresponding electric drive means via a corresponding input channel, wherein the subtransmissions are designed and arranged to interact with one another and with the common output shaft in such a way that interruptions in the torque output of the output shaft are avoided during gear shifts of the one or the other subtransmission. This invention can be used, among other things, for the electric drive of a vehicle in order to make possible a gear change free of traction force interruption.DESCRIPTION OF THE INVENTIONPrior ArtThe application Boosted Range Extender (http: / / www.heis.de / autos / article / Boosted-Range-Extender-three-drives-in-one-881580.html) is known from the prior art. Whereas only one electric machine is provided to drive the wheels in the boosted range extender, in the invention described here at least two electric machines used serve for the drive. The transmission is oriented on an AMT (Automated Manual Transmission), that is to say in the embodiment it is a spur gear set of countershaft construction, in which gear stage changes are carried out with shift elements which do not allow a powershift. In contrast, the transmission boosted range extender is based on a planetary gear set having fully power-shiftable frictional clutches.For example, DE 10 2009 034 435 A1 or DE 10 2005 049 992 A1 disclose electric drives in which one transmission per electric drive means has a partial transmission with the features mentioned at the beginning.The object is to provide a method for performing a processIt is the object of the invention to provide an electric drive, in particular for electric vehicle drives, wherein a transmission requires as few gear set pairs as possible for realizing different gears. In addition, the shift sleeves of the transmission should be able to be actuated with only one shift actuator.Solution of the ProblemThis object is achieved by the electric drive having the features of claim 1.The solution according to the invention is illustrated by means of FIGS. 1 and 2. An electric machine 1 (M 1) is coupled via a transmission input shaft 1 (A 10- 1) and via a gearwheel pair with fixed transmission ratio to a transmission intermediate shaft 1 (A 10- 3), for example designed as a solid shaft. A further electric machine 2 (M 2) is coupled via a transmission input shaft 2 (A 10- 2) and via a gearwheel pair with fixed transmission ratio to a transmission intermediate shaft 2 (A 10- 4), designed as a hollow shaft. Both the intermediate shaft A 10- 3 and the intermediate shaft A 10- 4 can be variably coupled to an output shaft A 10- 5 via one of two gear set pairs A 10- 10 or A 10- 11 by coupling shift sleeves A 10- 6 and / or A 10- 8 to the gear set pair A 10- 10, or shift sleeves A 10- 7 and / or A 10- 9 to the gear set pair A 10- 11. Furthermore, an internal combustion engine may be added to the depicted transmission, which may be coupled, for example, at the locations indicated by A10-12.An advantage of this embodiment is the small number of wheel set pairs (here A10-10 and A10-11), which are required for realizing different gears. In addition, the shift sleeves of the transmission can be actuated with only one shift actuator, for example, via a shift drum.Furthermore, in the construction shown here, a parking lock function can be carried out by simultaneously coupling intermediate shaft A10-3 (or A10-4) to A10-10 and A10-11. This takes place by engaging both shift sleeves A10-6 and A10-7 (or A10-8 and A10-9) and thus clamping the transmission.If the gearwheel, which is situated rotationally fixedly on hollow shaft A 10- 4 and between the two shift sleeves A 10- 8 and A 10- 9, is partially designed with apertures, the shift sleeves A 10- 8 and A 10- 9 can be designed as a shift sleeve for coupling shaft A 10- 4 and A 10- 10, or A 10- 11. The design of such a shift sleeve or of the gear necessary for this is shown in FIG. 11 at the center (exemplary functional principle) or on the right (exemplary design of the gear).In order to actuate a claw clutch to the left and right of a gearwheel pair (A11-2), in the case of a conventional design of two shift sleeves A11-5.1 and A11-6 (FIG. 11, left) are required. However, if the gear A 11- 7 (FIG. 11, center and right) is formed with apertures as shown, the shift sleeves A 11- 5.1 and A 11- 6 may be replaced by a common shift sleeve A 11- 5.2 (FIG. 11, center).Finally, by supplementing a third gear pair on the right of shift sleeve A 10- 7 between transmission intermediate shaft A 10- 3 and transmission output shaft A 10- 5, e-machine 1 (M 1) can be equipped with a third transmission ratio, which is likewise coupled via shift sleeve A 10- 7.Such a multi-speed transmission for an electric drive has at least one electric machine which transmits power via a first input to at least one solid shaft and at least one further electric machine which transmits power via a second input to at least one coaxially arranged hollow shaft, and these shafts can be coupled via at least one shift sleeve to at least one common gearwheel pair which transmits the power to at least one common output shaft.In a further exemplary embodiment, such a transmission can transmit the power of at least two electric machines and additionally of at least one internal combustion engine.In this case, at least one of the shift sleeves, which couples a common gearwheel pair to either the solid shaft or the hollow shaft, can be used for coupling a further gearwheel pair to the solid shaft or the hollow shaft, with the aim of achieving additional transmission ratios. The shift sleeve is designed in such a way that a further gearwheel pair can be coupled to the solid or hollow shaft.In a further exemplary embodiment, two separate shift sleeves can be arranged on the right and left of a gearwheel connected to the shaft in a rotationally fixed manner. In a further exemplary embodiment, these can be replaced by a single shift sleeve with guides, in which the gearwheel which is connected to the shaft in a rotationally fixed manner is designed with apertures. The shift sleeve is designed in such a way that it moves through these apertures in order to produce positively locking connections on both sides of the gearwheel, for example with two further gearwheel pairs.By means of a method, the transmission can be braced either on the solid shaft or on the hollow shaft by simultaneously coupling two different transmission ratios via two separate shift sleeves, and a parking lock function can thus be realized.This is a drive with at least two electric machines (EM 1 and EM 2) and at least two partial transmissions for transmitting the torques to a common output shaft. At least one of the subtransmissions is designed as an AMT or as a transmission oriented on an AMT (Automated Manual Transmission). This means that in the embodiment it is a spur gear set of countershaft construction, in which gear stage changes are carried out with shift elements which do not allow a load shift. Load shifts of the overall transmission and an uninterrupted torque output of the output shaft are made possible by a corresponding shift strategy in the interaction of the subtransmissions.Advantages of this drive are a transitionless profile of the torque during a transmission step change, a high torque at low rotational speed, an improved efficiency in the part load range, a high available rotational speed collective (high maximum rotational speed) and thus a smaller design of the electric machines and a lower weight. A further advantage is that no powershift clutches are required in the transmission.Such an electric drive can be connected in modular fashion multiple times via gears (not shown in the drawing). An embodiment is the parallel construction of at least two electric drives according to claim 1, the output shafts A10-5 of which serve as input shafts for a transmission according to claim 1 and multiples of this combination.Advantageous exemplary embodiments are described below and / or are described in the dependent claims.Range Extender OperationThe range extender as the engine may be integrated at four different locations within the drive. Where it is integrated, it is based on the design of the transmission and on the performance data of EM and RE. In the case of a similar operating rotational speed range, coupling to EW is expedient, and in the case of a higher rotational speed of the EM, a connection to one of the intermediate shafts makes sense.During hybrid series operation, one EM serves to drive the wheels and the other EM acts as a generator. Thus, a shift in this operation is associated with a traction force interruption or requires a mixed operation (see below).Mechanical Drive by REWith an engine (KM) as a range extender, it can likewise serve directly as a mechanically coupled drive for the wheels. That is, besides the function as a serial hybrid, the function as a parallel hybrid is also possible. In this case, the KM can be operated at the same transmission ratios as the subsystem to which it is coupled. In addition, the EM of the other subsystem may be used for boosting and traction force non-interrupted shifting.Mixed ModeThe mixed operation consists of two possible operations. Thus, on the one hand, the KM can drive the wheels directly and, at the same time, the EM of the same subsystem operates as a motor or generator (load point displacement or charging of the electrical energy store). The second electric machine can in turn be used as an additional drive (boosting) or for switching.A second possibility for mixed operation is the support of the circuits in range extender operation already mentioned. While the drive subsystem is undergoing a gear change, the range extender subsystem could serve to maintain torque.Inscription of the DrawingsFIG. 1 : Transmission gear set structure (differential not shown)A10-1: Transmission input shaft 1 with fixed transmission ratio to intermediate shaft A10-3A10-2: Transmission input shaft 2 with fixed transmission ratio to intermediate shaft A10-4A10-3: Intermediate transmission shaft 1 with variable connection to A10-10 or A10-11A10-4: Intermediate transmission shaft 2 (hollow shaft) with variable connection to A10-10 or A10-11A10-5: Transmission Output Shaft (Differential not shown)A10-6: First Speed Shift Sleeve for Coupling A10-3 and A10-10A10-7: Second Speed Shift Sleeve for Coupling A10-3 and A10-11A10-8: First Speed Shift Sleeve for Coupling A10-4 and A10-10A10-9: Second Speed Shift Sleeve for Coupling A10-4 and A10-11A10-10: First gear set pair for coupling A10-3 or A10-4 and A10-5A10-10: Wheel set pair of the second gear for coupling A1-3 or A1-4 and A10-5A10-12: Possible locations in the transmission for coupling an internal combustion engine FIG. 2 : Embodiment of two individual shift sleeves as a common shift sleeveA 11- 1: Transmission input shaft 2 (A 10- 2) with fixed transmission ratio A 11- 2 to transmission intermediate shaft 2 (A 11- 3)A 11- 2: Gear pair between transmission input shaft 2 (A 11- 1) and transmission intermediate shaft 2 (A 11- 3)A11-3: Intermediate transmission shaft 2 (hollow shaft) (A10-4) with variable connection to transmission output shaft (not shown) via A11-5.1 and A11-6 (left), or A11-5.2 (middle), respectivelyA 11- 4: Intermediate transmission shaft 1 (A 10- 3) with variable connection to transmission output shaft (not depicted)A11-5.1: First Speed Shift Sleeve for Coupling A11-3 and Transmission Output Shaft (not shown)A11-6: Second speed shift sleeve for coupling A11-3 and the transmission output shaft (not shown) A11-5.2: First and second speed common shift sleeve for coupling A11-3 and the transmission output shaft (not shown)A11-7: Gearwheel with apertures for guiding the shift sleeve A11-5.2

Claims

An electric drive for transmitting the torques of at least two electric drive means via a transmission to an output shaft (A10-5), wherein the transmission has a partial transmission per electric drive means and each partial transmission is coupled to the corresponding electric drive means via a corresponding input channel, wherein the partial transmissions are designed and arranged interacting with one another and with the common output shaft (A10-5) in such a way that interruptions in the torque output of the output shaft (A10-5) are avoided during shifting operations of the one or the other partial transmission, characterized in that a gearwheel (A11-2) has apertures and a shift sleeve (A11-5.2) is designed in such a way that it moves through these apertures in order to produce positively locking connections on both sides of the gearwheel (A11-2) with two further gearwheel pairs (A11-2, A11-3).Electric drive according to Claim 1, characterized in that at least one of the subtransmissions is designed as an AMT transmission or as an AMT-oriented transmission, having a spur gear set of countershaft design during the transmission stage change are designed with shift elements which do not allow a powershift.Electric drive according to Claims 1 to 2 characterised in that the subtransmissions are designed identically.Electric drive according to Claim 1 to 3da characterized in that at least two drive means according to Claim 1 connected in parallel are coupled to an output shaft (A10-5) via at least one gearbox according to Claim 1.Electric drive according to one of Claims 1 to 4, characterized in that the subtransmissions are designed in such a way that at least one electric machine transmits power via a first input to at least one solid shaft and at least one further electric machine transmits power via a second input to at least one coaxially arranged hollow shaft, and each of these shafts is designed such that it can be coupled to at least one common gearwheel pair via in each case at least one shift sleeve in order to transmit the power to the at least one common output shaft.Electric drive according to one of Claims 1 to 5 or 11, characterized in that at least one shift sleeve which couples a common gearwheel pair to either the solid shaft or the hollow shaft is designed such that it can be coupled to the solid shaft or the hollow shaft for a further gearwheel pair.A vehicle comprising at least one driven wheel wheel characterized in that the vehicle comprises an electric drive according to any one of claims 1 to 4 for driving the wheel via the common output shaft (A10-4).Vehicle according to Claim 7da, characterized in that at least one energy source is provided in the vehicle.Vehicle according to Claim 7 or 8, characterized in that the electric drive also has at least one range extender (RE), particularly preferably designed in the form of a heat engine, the at least one range extender (RE) being provided assigned to one of the subtransmissions or in each case one RE assigned to each subtransmission and being designed to be coupled either to one of the intermediate shafts or to one of the input shafts.Vehicle according to Claims 7 to 9, characterized in that an engine is used as the range extender, with the result that the drive can be operated both as a series and as a parallel hybrid.Vehicle according to Claims 7 to 10, characterized in that the range extender is designed as a mechanically coupled drive element for the realization of load circuits.Vehicle according to Claims 7 to 11, characterized in that the vehicle has two driven axles, each axle being designed to be driven by an electric drive according to Claims 1 to 4, or the one or the other axle being designed to be driven via a heat engine, or the two drives connected in parallel from Claims 1 to 4 acting on in each case the one or the other axle and hence on the common output duct.A method in an electric drive according to one of claims 1 to 6, characterised in that the transmission is braced either the solid shaft or the hollow shaft by simultaneously coupling two different transmission ratios via two separate shift sleeves, and a parking lock function is thus realised.

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