Rotor shaft system with increased stiffness
A rotor shaft system for a vehicle includes a rotor shaft having a first shaft end opposite a second shaft end. The rotor shaft has a first segment and a second segment defined between the first shaft end and the second shaft end. The rotor shaft system includes a shaft gear coupled to the rotor shaft between the first shaft end and the first segment, and a shaft sleeve coupled to the first segment so as to surround a portion of the shaft gear. The rotor shaft system includes a lubrication system defined at least partially through the rotor shaft and the shaft sleeve. The lubrication system is to supply a fluid to at least a portion of the rotor shaft and the shaft sleeve.
1 . A rotor shaft system for a vehicle, comprising:
a rotor shaft including a first shaft end opposite a second shaft end and having a first segment and a second segment defined between the first shaft end and the second shaft end;
a rotor of an electric motor including end rings and disposed on the second segment of the rotor shaft;
a shaft gear coupled to the rotor shaft between the first shaft end and the first segment, wherein the shaft gear is on an opposite side of the first segment from the rotor;
a shaft sleeve coupled on the first segment and surrounding a portion of the shaft gear, the shaft sleeve having a first end and a second end; and
a lubrication system defined at least partially through the rotor shaft and the shaft sleeve, the lubrication system configured to supply a fluid to at least a portion of the rotor shaft and the shaft sleeve,
wherein the shaft sleeve extends over the shaft gear with the first end overlaps and is disposed about the shaft gear,
wherein the second end is disposed in contact with one of the end rings.
2 . The rotor shaft system of claim 1 , wherein the rotor shaft includes a first shaft bore defined from the first shaft end through the first segment and at least part of the second segment, and the first shaft bore is in fluid communication with the lubrication system.
3 . The rotor shaft system of claim 2 , wherein the lubrication system includes a cross-bore defined through the second segment in fluid communication with the first shaft bore.
4 . The rotor shaft system of claim 3 , wherein the second segment includes a keyway defined axially on an outer perimeter of the second segment, and the cross-bore is in fluid communication with the keyway.
5 . The rotor shaft system of claim 4 , wherein the keyway is configured to couple the rotor shaft to the rotor of the electric motor of the vehicle.
6 . The rotor shaft system of claim 4 , wherein a lubrication conduit is defined through part of the first segment and the second segment, and is in fluid communication with the keyway.
7 . The rotor shaft system of claim 6 , wherein the shaft sleeve includes a sleeve lubrication bore in fluid communication with the lubrication conduit.
8 . The rotor shaft system of claim 1 , wherein:
the end rings include a first end ring and a second end rings,
the first end ring includes a countersunk region with a contact surface facing the shaft sleeve,
the shaft sleeve extends into the countersunk region and contacts the first end ring at the contact surface.
9 . The rotor shaft system of claim 1 , wherein the first segment has a first diameter that is greater than a second diameter of the second segment.
10 . The rotor shaft system of claim 1 , further comprising a shaft collar coupled to the second segment proximate the second shaft end.
11 . The rotor shaft system of claim 10 , wherein:
the second segment includes a feed groove; and
the shaft collar includes at least one opening in fluid communication with the feed groove.
12 . A vehicle, comprising:
an electric motor including a rotor with magnetic elements contained between end rings; and
a rotor shaft system coupled to the electric motor, the rotor shaft system including:
a rotor shaft including a first shaft end opposite a second shaft end and having a first segment and a second segment defined between the first shaft end and the second shaft end, the second segment coupled to the rotor, wherein the rotor is disposed on the second segment of the rotor shaft;
a shaft gear defined on the rotor shaft between the first shaft end and the first segment, wherein the shaft gear is on an opposite side of the first segment from the rotor;
a shaft sleeve coupled on the first segment so as to be disposed between the shaft gear and the rotor, and the shaft sleeve surrounding a portion of the shaft gear, the shaft sleeve having a first end and a second end;
a shaft collar coupled to the second segment between the rotor and the second shaft end, and the shaft collar is configured to clamp the rotor and the shaft sleeve to the rotor shaft; and
a lubrication system defined through a portion of the rotor shaft and the shaft sleeve, the lubrication system configured to supply a fluid to at least the portion of the rotor shaft, the shaft sleeve and the electric motor,
wherein the shaft sleeve extends over the shaft gear with the first end overlaps and is disposed about the shaft gear,
wherein the second end is disposed in contact with one of the end rings.
13 . The vehicle of claim 12 , wherein the rotor shaft includes a first shaft bore defined to extend from the first shaft end through the first segment and at least part of the second segment, and the first shaft bore is in fluid communication with the lubrication system.
14 . The vehicle of claim 13 , wherein the lubrication system includes a cross-bore defined through the second segment in fluid communication with the first shaft bore.
15 . The vehicle of claim 14 , wherein the second segment includes a keyway defined axially on an outer perimeter of the second segment, the keyway coupled to a key associated with the rotor, and the cross-bore is in fluid communication with the keyway.
16 . The vehicle of claim 15 , wherein:
a lubrication conduit is defined through part of the first segment and the second segment, and the lubrication conduit in fluid communication with the keyway; and
the shaft sleeve includes a sleeve lubrication bore, and the sleeve lubrication bore is in fluid communication with the lubrication conduit.
17 . The vehicle of claim 12 , wherein:
the end rings include a first end ring and a second end rings,
the first end ring includes a countersunk region with a contact surface facing the shaft sleeve,
the shaft sleeve extends into the countersunk region and contacts the first end ring at the contact surface, and
the shaft sleeve overlaps and encloses a recessed area defined in the first segment adjacent to the shaft gear.
18 . The vehicle of claim 12 , wherein the first segment has a first diameter that is greater than a second diameter of the second segment.
19 . The vehicle of claim 12 , wherein:
the second segment includes a feed groove; and
the shaft collar includes at least one opening in fluid communication with the feed groove.
20 . The vehicle of claim 12 , further comprising a sensor coupled to a second shaft bore at the second shaft end and the second shaft bore extends axially toward the second segment.