Patent ID: 12206300

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

FIG.1shows how a hollow cylindrical stator10is inserted in a stator housing12. The stator housing12has an inner casing surface14directed towards the inside in the radial direction. The stator housing12also has a receiving opening16which is formed in the axial direction of the cylindrical stator housing12. The hollow cylindrical stator10is pressed into the receiving opening16of the stator housing12in the longitudinal direction of the stator housing12, so that the stator10is arranged rotationally fixedly in the stator housing12. Rotationally fixed indicates that the stator10cannot twist in the circumferential direction relative to the stator housing12.

FIG.2shows a section through the stator housing12in which the stator10described inFIG.1is pressed.

FIGS.3to6show an arrangement of the stator housing12on a flange18. For this, in a first step, a centering pin20is inserted in a stator cavity22of the hollow cylindrical stator10via the receiving opening16of the stator housing12, and clamped against an inner casing surface24of the stator10which is directed towards the inside in the radial direction. In a second step, the stator housing12is pushed onto the flange18.

FIG.4shows that before the stator housing12is pushed onto the flange18, first the centering pin20is inserted and clamped in the stator cavity22. On a side facing the flange18, the centering pin20has a protrusion40which protrudes through the flange18or may be introduced through an opening26inside the flange18in order to centre the flange18on the stator housing12.

FIG.5shows how the stator housing12is pushed onto the flange18. The flange18has a plurality of fixing openings28through which a fixing device38may be introduced and connected to a transmission30.

FIG.6shows a detail section of the stator housing12in the region of the flange18. The flange18is pushed onto the stator housing12and connected by substance bonding to the stator housing12. In the present exemplary embodiment, the substance-bonded connection29is a welded connection.

FIGS.7to8show a fixing and alignment of the stator housing12on a transmission30. The transmission30has a transmission input shaft32. The stator housing12is arranged on the transmission30via a centering pin20such that a longitudinal axis34of the transmission input shaft32is oriented coaxially to the longitudinal direction36of the centering pin20arranged in the stator10. The precise alignment of the stator housing12relative to the transmission30is a first step in reducing the air gap between a rotor44, which is inserted in the stator cavity, and the stator10. The air gap is thus formed in the radial direction between the rotor44and the stator10. After precise alignment, the stator housing12is secured or fixed to the transmission30. In the present exemplary embodiment, this takes place by force fit via fixing device38in the form of screws which are guided through fixing openings28of the flange18and screwed to the transmission30.

FIG.8shows a section through the stator housing12placed on the transmission30. It is evident here that a protrusion40of the centering pin20engages in or is introduced into a receiver42of the transmission input shaft32, in order to orient the longitudinal direction36of the centering pin20coaxially to the longitudinal axis34of the transmission input shaft32.

FIG.9shows a view of a rotor44for arrangement in the stator cavity22. The rotor44has a hollow cylindrical sheet stack46which includes several sheet stack segments arranged successively in the axial direction. A cover disc48is arranged on each end of the stator stack46in the axial direction. A rotor hollow shaft50is moulded and/or cast onto an inner casing surface of the hollow cylindrical sheet stack46. In comparison with conventional shafts or rotors, a rotor with a rotor hollow shaft50has a reduced weight. The rotor hollow shaft50, at an axial end, has a hollow shaft opening52via which a bearing device54is inserted in the hollow shaft and therein fixed via a securing ring56to the bearing seat58formed in the rotor hollow shaft50. The bearing device54is formed so as to be pivotal.

FIGS.10to12show the design of the bearing device54which is formed from a receiving ring60and a bearing62arranged in the receiving ring60.

FIG.10shows that on an end face64oriented in the axial direction of the receiving ring60, the receiving ring60has two receiver grooves66, spaced apart from one another, for receiving the bearing62. The bearing62is introduced into the receiving ring60via a translational movement. Here, a longitudinal axis68of the bearing62is arranged perpendicularly to a longitudinal axis70of the receiving ring60.

It is furthermore evident that the bearing62has a convex form on a casing surface72which faces outward in the radial direction. The receiving ring has a concave form on an inside74which faces inward in the radial direction.

FIG.11shows that the bearing62has been introduced into the receiving ring60via the translational movement along the receiving grooves66. The bearing62is now pivoted via a pivot movement such that the longitudinal axis68of the bearing62coincides with the longitudinal axis70of the receiving ring60.

FIG.12shows the bearing62pivoted in the receiving ring60, wherein the longitudinal axis68of the bearing62is the same as the longitudinal axis70of the receiving ring60. In this way, a spherical bearing62is provided which may compensate for axial tolerances between the longitudinal axis34of the transmission input shaft32and a rotor longitudinal axis of the rotor44.

FIG.13shows a view of the stator housing12which is attached to the transmission30and in which the rotor44is introduced into the stator cavity22via the receiving opening16and connected to the transmission input shaft32by force fit via screws76. Then a bearing shield78is placed on the stator housing12in order to close the receiving opening16. On a side facing the rotor44, the bearing shield78has a bearing pin80which engages in a rotor cavity82of the rotor hollow shaft50and in the pivotally attached bearing device54which is arranged in the rotor cavity82, such that the rotor44is mounted so as to be rotatable about its rotor longitudinal axis.

FIG.14shows a section through the transmission30and the electric machine including a stator housing12. By precise alignment of the stator housing12relative to the longitudinal axis34of the transmission input shaft32, and by arranging a spherical bearing device54in the rotor hollow shaft50of the rotor44, tolerances may be compensated so that the air gap in the radial direction between the rotor44and the stator10is reduced, such that the power density of the electric machine is increased.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.