Patent ID: 12255515

DETAILED DESCRIPTION

Certain terminology is used in the following description for convenience only and is not limiting. The words “inwardly” and “outwardly” refer to directions toward and away from the parts referenced in the drawings. “Axially” refers to a direction along the axis of a shaft. “Radially” refers to a direction normal to an axis. A reference to a list of items that are cited as, for example, “at least one of a or b” (where a and b represent the items being listed) means any single one of the items a or b, or a combination of a and b thereof. This would also apply to lists of three or more items in like manner so that individual ones of the items or combinations thereof are included. The terms “about” and “approximately” encompass + or −10% of an indicated value unless otherwise noted. The terminology includes the words specifically noted above, derivatives thereof and words of similar import.

Referring toFIGS.1and2, a first embodiment of a hybrid drive assembly10for a motor vehicle is shown. The hybrid drive assembly10is located between the crankshaft12of an internal combustion engine and further part of the drive-line, for example a torque converter15(schematically represented) that is connected to a transmission.

The hybrid drive assembly includes a housing20in which an electric motor (e-motor)22is located. The e-motor22is formed from a stator24mounted to the housing20as well as a rotor26rotatably mounted within the stator24. The rotor26is connected to an input shaft30that is adapted to be connected to a transmission, for example via a torque converter connection14.

The rotor26includes a rotor support28that is connected to the input shaft30. The rotor support28has a generally axially extending mounting flange28A with a stop28B located at one axial end region of the mounting flange28A. In the illustrated embodiment, the rotor support28is formed in one piece. However, this could be formed as multiple pieces that are connected together. A rotor stack27that forms that magnetized part of the rotor26is located on the mounting flange28A. First and second rotor rings32,34, which can be made of aluminum or another non-magnetic material, are located on respective first and second axial sides of the rotor stack27. A diaphragm spring36is located on the mounting flange28A on an opposite axial end region from the stop28B and clamps the second rotor ring34, the rotor stack27, and the first rotor ring32against the stop28B in order to rotationally fix the rotor stack27to the mounting flange28A.

A drive plate assembly40that is configured to be connected to the crankshaft12of the internal combustion engine is provided, with the drive plate assembly40including an output flange42that is used in connection with the rotor26to form an overload clutch41. In the first embodiment of the hybrid drive assembly10, the output flange42is rotationally fixed to the diaphragm spring36such that, upon application of a torque spike, the diaphragm spring36rotates relative to the mounting flange28A, forming the overload clutch41. The necessary torque to activate the overload clutch can be set based on the frictional force between the diaphragm spring36and the axially extending mounting flange28A upon which it is arranged based on the surface finish or texture of the mounting flange28A and the contact area of the diaphragm spring36thereon.

As shown inFIGS.1and2, the output flange42can be rotationally fixed to the diaphragm spring36via one or more projections44on the output flange42engaging in teeth38of the diaphragm spring36. While a toothed engagement is shown inFIG.2, other types of rotationally fixed connections between the output flange42and the diaphragm spring36can be provided. These are preferably releasably engaged in order to allow for repair and maintenance.

Still with reference toFIG.1, in this embodiment the drive plate assembly40includes an input plate46that is configured to be connected to the crankshaft12, as well as damper spring(s)48located between the input plate46and the output flange42, forming a damper assembly. This is used to smooth torque fluctuations between the torque transmitted via the crankshaft12of the internal combustion engine to the drive plate assembly40versus the torque provided by the e-motor22.

In the first embodiment of the hybrid drive assembly10, the input shaft30is configured to be supported on one axial end30A in an opening13in an end of the crankshaft12. Preferable, this support is provided via a needle bearing61.

As shown, a further bearing62is provided between a fixed portion extending from the housing20and the input shaft30to support the input shaft30. A seal63is also shown. The torque converter connection14is preferably also rotationally fixed to the input shaft30via a splined connection, as shown, and is drivingly engaged with a housing of the torque converter15.

Still with reference toFIG.1, preferably a revolver rotor50is connected to the rotor26and a position sensor52is connected to the housing20. The resolver rotor50is used to determine a position of the rotor26which is useful for start and stop operations of the e-motor22. As shown inFIG.1, the resolver rotor50is preferably located on a radially inner side of the mounting flange28A.

Referring now toFIG.3, a second embodiment of the hybrid drive assembly10′ is shown. The second embodiment of the hybrid drive assembly10′ is similar to the first embodiment of the hybrid drive assembly10and like elements have been labeled with the same element numbers. In this arrangement, instead of the output flange42′ of the drive plate assembly40′ being rotationally fixed to the diaphragm spring36′, the output flange42′ is frictionally engaged to at least one of the diaphragm spring36′ or the second rotor ring34′. This forms a frictional engagement when the diaphragm spring36′ is pressed onto the mounting flange28A to clamp the second rotor ring34′, the rotor stack27, and the first rotor ring32against the stop28B, with the output flange42′ being located between the diaphragm spring36′ and the second rotor ring34′, and this frictional engagement provides that, upon application of a torque spike sufficient to overcome the frictional engagement force, the output flange42′ rotates relative to the at least one of the diaphragm spring36′ or the second rotor ring34′.

Here, the frictionally engaged axial surfaces of the diaphragm spring36′, the output flange42′ and the second rotor ring34′ act as a clutch plate/counter-plate(s) combination of an overload clutch41′ that is pressed together by the force of the diaphragm spring36′. The clamping force generated by the diaphragm spring36′ can be adjusted, and/or the friction properties of the engaging axial faces of the clutch/counter-plate(s) combination thus formed can be adjusted in order to adjust (i.e., set) the release torque for the thus formed overload clutch41′.

Accordingly, in this case the overload clutch41′ also protects the hybrid drive assembly10′ as well as other drive line components from a torque spike causing damage.

Still with reference toFIG.3, in the second embodiment, the drive plate assembly40′ includes an input plate46that is configured to be connected to the crankshaft12and damper springs48are located between the input plate46and the output flange42′. Accordingly, a damper assembly is provided between the crankshaft12and the input shaft30in order to smooth out any torque fluctuations transmitted via the crankshaft12from the internal combustion engine.

Referring now toFIG.4, a third embodiment of a hybrid drive assembly10″ is shown. The third embodiment of the hybrid drive assembly10″ is similar to the second hybrid drive assembly10′ and like elements have the same element numbers. The output flange42″ is formed with a portion that is frictionally engaged to at least one of the diaphragm spring36″ or the second rotor ring34″ to form an overload clutch41″, similar to the overload clutch41′ described above.

In this embodiment, the drive plate assembly40″ is formed having a rotationally fixed connection between the output flange42″ and the input plate46″. Therefore, no separate damager assembly is provided via the drive plate assembly40.

A method of forming an overload clutch41,41′,41″ for protecting a hybrid drive arrangement10,10′,10″ is also provided. In each case, the hybrid drive arrangement includes a housing20as well as a stator24mounted to the housing20and a rotor26connected to an input shaft30that is adapted to be connected to a transmission, preferably via a torque converter connection14as discussed above. The rotor26is rotatably mounted within the stator24. The method comprises providing the rotor26with a rotor support28connected to the input shaft30, with the rotor support28including a generally axially extending mounting flange28A with a stop28B located at one axial end region of the mounting flange28A, and a rotor stack27located on the mounting flange28A. First and second rotor rings32,34are located on respective first and second axial sides of the rotor stack27, with the rotor rings32,34preferably being made of a non-ferrous material.

The method further includes pressing a diaphragm spring36.36′,36″ on the mounting flange28A on an opposite axial end region from the stop28B, clamping the second rotor ring34,34′,34″, the rotor stack27, and the first rotor ring32against the stop28B in order to rotationally fix the rotor stack27to the mounting flange28A.

The method further includes providing a drive plate assembly40,40′,40″ that is configured to be connected to a crankshaft12of an internal combustion engine, with the drive plate assembly40,40′,40″ includes an output flange42,42′,42″.

The method further includes frictionally engaging the output flange42′,42″ to at least one of the diaphragm springs36′,36″ or the second rotor ring34′,34″ such that application of a torque spike causes the output flange42′,42″ to rotate relative to the at least one of the diaphragm spring36′,36″ or the second rotor ring34′,34″, as shown inFIGS.3and/or4. Preferably, the frictional engagement is provided by locating that output flange42′,42″ between the diaphragm spring36′,36″ and the second rotor ring34′,34″ in order to form the overload clutch41′,41″.

Alternatively, the method can include rotationally fixing the output flange42to the diaphragm spring36such that application of a torque spike causes the diaphragm spring36to rotate relative to the mounting flange28A, as shown inFIGS.1and2.

As discussed above, the rotational fixing of the output flange42to the diaphragm spring36can include the use of projections44on the output flange42engaging in teeth38on the diaphragm spring36, as shown inFIGS.1and2.

In either case, the method provides overload protection through the formation of an overload clutch41,41′,41″.

Having thus described the presently preferred embodiments in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description, could be made without altering the inventive concepts and principles embodied therein. It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. The present embodiments and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope that is indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein.

LIST OF REFERENCE SYMBOLS

10,10′,10″ hybrid drive assembly12crankshaft13opening14torque converter connection15torque converter20housing22e-motor24stator26rotor27rotor stack28rotor support28A mounting flange28B stop30input shaft30A one axial end32first rotor ring34,34′,34″ second rotor ring36,36′,36″ diaphragm spring38teeth40,40′,40″ drive plate assembly41,41′,41″ overload clutch42,42′,42″ output flange44projections46,46″ input plate48damper spring(s)50resolver rotor52position sensor61needle bearing62bearing63seal