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DE-102018101717-B4 - LIGHTWEIGHT ROTOR END PLATE FOR ELECTRIC MACHINE

DE102018101717B4DE 102018101717 B4DE102018101717 B4DE 102018101717B4DE-102018101717-B4

Abstract

Electric machine, including: a rotor (104); an end plate (100) defining an opening, an inner mating surface (128b) and a compensating ring surface, wherein the mating surface (128b) extends from a circumference of the opening to a first diameter, the compensating ring surface extends from a second diameter, which is larger than the first, to an outer circumference (130) of the end plate (100), and the compensating ring surface is adjacent to the rotor (104) before assembly and the mating surface (128b) is spaced apart from the rotor (104); a shaft (106) and a locknut (102), wherein the rotor (104) and the locknut (102) are each attached to the shaft (106) and are arranged such that the end plate (100) is inserted between the locknut (102) and the rotor (104) and the inner locknut surface (128b) deforms when the locknut (102) is tightened until the inner locknut surface (128b) abuts the rotor (104).

Inventors

  • Cyrille Goldstein
  • Joel Hetrick

Assignees

  • FORD GLOBAL TECHNOLOGIES, LLC

Dates

Publication Date
20260513
Application Date
20180125
Priority Date
20170130

Claims (13)

  1. An electric machine comprising: a rotor (104); an end plate (100) defining an opening, an inner counternut surface (128b), and a compensating ring surface, wherein the counternut surface (128b) extends from a circumference of the opening to a first diameter, the compensating ring surface extends from a second diameter, which is larger than the first, to an outer circumference (130) of the end plate (100), and the compensating ring surface is adjacent to the rotor (104) before assembly, and the counternut surface (128b) is spaced apart from the rotor (104); a shaft (106) and a locknut (102), wherein the rotor (104) and the locknut (102) are each attached to the shaft (106) and are arranged such that the end plate (100) is inserted between the locknut (102) and the rotor (104) and the inner locknut surface (128b) deforms when the locknut (102) is tightened until the inner locknut surface (128b) abuts the rotor (104).
  2. Electric machine according to Claim 1 , wherein the compensating ring surface and the inner locknut surface (128b) each define a plane, each plane being inclined to an axis of rotation defined by the rotor (104) and the plane defined by the compensating ring surface and the plane defined by the inner locknut surface (128b) are not coplanar.
  3. Electric machine according to Claim 1 , wherein the locknut (102) clamps the end plate (100) after the locknut (102) is pressed along the shaft (106) to clamp the end plate (100) against the rotor (104).
  4. Electric machine according to Claim 1 , wherein the non-coplanar inner locknut surface (128b) and compensating ring surface are configured to distribute a clamping force associated with tightening the locknut (102).
  5. Electric machine according to Claim 4 , wherein the clamping force is distributed between an axis of rotation of the rotor (104) and a section near an outer circumference (130) of the rotor (104).
  6. Electric machine according to Claim 1 , wherein the end plate (100) is convex with respect to the rotor (104) before assembly.
  7. Electric machine according to Claim 1 , wherein the end plate (100) has a front surface (100a) and a rear surface (100b), wherein the rear surface (100b) is adjacent to and closest to the rotor (104) and the rear surface (102b) defines at least two coolant troughs extending radially outwards from the center.
  8. Electric machine according to Claim 1 , wherein the end plate (100) defines a plurality of reinforcing ribs (122) arranged radially around the opening, such that the end plate (100) defines a larger cross-sectional area than a rotor end plate which is flat.
  9. Electric machine according to Claim 8 , wherein each of the plurality of reinforcing ribs (122) has a wider section and a thinner section and the reinforcing ribs (122) are arranged radially around the center of the end plate (100) such that the thinner section of each of the reinforcing ribs (122) is positioned closest to the center.
  10. An electrical machine comprising: a rotor (104); a stator surrounding the rotor (104) in a circumferential direction; and a rotor end plate (100) defining a central mounting hole, a counternut surface ring, and a compensating ring surface, wherein the counternut surface ring extends from a circumference of the central mounting hole to a first diameter, the compensating ring surface extends between a second diameter larger than the first and an outer circumference (130) of the rotor end plate (100), the counternut surface ring defines a plane, and the compensating ring surface defines a plane, and the plane defined by the counternut surface ring is spaced apart from the plane defined by the compensating ring surface; a locknut (102) and a shaft (106), wherein the rotor (104) and the locknut (102) are each arranged on the shaft (106) and are configured such that the end plate (100) is positioned between the rotor (104) and the locknut (102). is laid down and the counternut surface ring is deformed in the direction of the rotor (104) when the counternut (102) is screwed on.
  11. Electric machine according to Claim 10 , wherein the end plate (100) is convex with respect to the rotor (104) before assembly.
  12. An electric machine comprising: a laminated core defining a rotor (104) mounted on a shaft (106); a locknut (102); and an end plate (100) defining a compensating ring (120), a locknut surface (128b), and a plurality of reinforcing ribs (122) defined by a region between the compensating ring (120) and the locknut surface (128b), wherein the compensating ring (120) defines a plane and the locknut surface (128b) defines a plane, wherein the plane defined by the compensating ring (120) and the plane defined by the locknut surface (128b) are in a non-coplanar relationship, and the locknut surface (128b) of the end plate (100) is configured to deform towards the rotor (104) when the locknut (102) is tightened.
  13. Electric machine according to Claim 12 , wherein the non-coplanar relationship of the plane defined by the compensating ring (120) and the plane defined by the locknut surface (128b) is configured to distribute a clamping force in association with the locknut (102) and the end plate (100).

Description

TECHNICAL AREA The present disclosure relates to electrical machines for use in electric and hybrid electric vehicles, which are capable of acting either as a motor or as a generator. GENERAL STATE OF THE ART Vehicles, such as battery electric vehicles (BEVs) and hybrid electric vehicles (HEVs), contain a traction battery assembly that acts as a power source. The traction battery assembly is electrically connected, for example, to an electric motor that provides torque to driven wheels. The traction battery assembly may include components and systems that assist in managing vehicle power and operation. It may also include high-voltage components and an air or liquid thermal management system for temperature control. Electrical machines typically include a stator and a rotor that work together to convert electrical energy into mechanical energy, or vice versa. Electrical machines may include thermal management systems to cool the stator, the rotor, or both. US 2008 / 0 174 200 A1 discloses a method for manufacturing a rotor of an electric motor and the electric rotor. SUMMARY According to one embodiment, an electric machine can include a rotor and an end plate. The end plate can define an opening, an inner mating surface, and a compensating ring surface. The mating surface can extend from a circumference of the opening to a first diameter. The compensating ring surface can extend from a second diameter, larger than the first diameter, to an outer circumference of the end plate. Before assembly, the compensating ring surface can be adjacent to the rotor, and the mating surface can be spaced apart from the rotor. According to a further embodiment, an electric machine can include a rotor, a stator circumferentially surrounding the rotor, and a rotor end plate. The rotor end plate preferably defines a central mounting hole, a locking ring, and a compensating ring surface. The locking ring can extend from a circumference of the central mounting hole to a first diameter. The compensating ring surface can extend from a second diameter, larger than the first diameter, to an outer circumference of the rotor end plate. The locking ring can define one plane, and the compensating ring surface can define another plane. The plane defined by the locking ring is preferably spaced apart from the plane defined by the compensating ring surface. According to yet another embodiment, an electric machine is disclosed. The electric machine preferably comprises a laminated core defining a rotor mounted on a shaft, a locknut, and an end plate. The end plate can define a compensating ring, a locknut surface, and a plurality of reinforcing ribs defined by a region between the compensating ring and the locknut surface. The compensating ring preferably defines a plane, and the locknut surface defines a plane. The plane defined by the compensating ring and the plane defined by the locknut surface can be in a non-coplanar relationship. The locknut surface of the convex end plate can be configured to deform the rotor when the locknut is tightened. BRIEF DESCRIPTION OF THE DRAWINGS 1 is a schematic representation of an exemplary hybrid vehicle according to an embodiment of this disclosure.2 is a perspective view of an exemplary electric motor according to an embodiment of this disclosure.2 -A is a side view, in cross-section, of a section of an exemplary electrical machine along the cross-sectional line 2-A in 2 .3 is a front top view of a rotor end plate according to one embodiment of this disclosure.4 is a rear top view of a rotor end plate according to one embodiment of this disclosure.5 is a side view, in cross-section, of a rotor end plate along the cross-sectional line 5-A in 3 . DETAILED DESCRIPTION Detailed embodiments of the present invention are disclosed here as requested; however, it is understood that the disclosed embodiments are purely exemplary of the invention, which exists in various and alternative forms. The figures are not necessarily to scale; some features may be greatly enlarged or reduced to show details of certain components. Accordingly, the specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis to teach a person skilled in the art the diverse applications of the present invention. Referring to 1 Figure 16 is an exemplary plug-in hybrid electric vehicle (PHEV) and is generally referred to as vehicle 16. Vehicle 16 includes a transmission 12 and is driven by at least one electric machine 18 with selective assistance from an internal combustion engine 20. The electric machine 18 can be an alternating current (AC) electric motor, which is mounted in 1 The electric machine 18 is depicted as the "motor" 18. The electric machine 18 receives electrical power and provides torque to propel the vehicle. The electric machine 18 also serves as a generator to convert mechanical power into electrical power through regenerative braking. The gearbox 1