Granted Patent B2

US 12,362,633 · App. 18/043,283 · Granted Jul 15, 2025

Inventor: Stefano Rustichelli (Reggio Emilia, IT)

Assignee: WUHAN LOTUS CARS CO., LTD.

H02K9/19H02K1/2706H02K5/203H02K7/003

Abstract

Claims (29)

1. An electric machine cooling system comprising:

an electric machine having an inner rotor ( 12 ) and an outer stator, the inner rotor being rotatable about an axis of rotation and having or forming an inner hollow shaft;

a cooling cartridge arranged inside and coaxial to the inner hollow shaft of the inner rotor, the cooling cartridge being interchangeably attached to the inner rotor so as to be rotatable with the inner rotor about the axis of rotation the cooling cartridge comprising:

an inner coolant tube having an internal coolant duct configured to lead coolant from an inlet opening of the inner coolant tube to a closed dead-end of the cooling cartridge, and

an outer coolant sleeve, the outer coolant sleeve being arranged between the inner coolant tube and the inner rotor and comprising a plurality of coolant channels which are fluidically connected with the internal coolant duct via at least one connection channel in a region of the closed dead-end and which are configured to lead the coolant from the at least one connection channel to at least one outlet opening of the outer coolant sleeve; and

a closing cap shaft being aligned with and arranged adjacent to the cooling cartridge so as to secure the cooling cartridge inside the inner hollow shaft of the inner rotor,

wherein the closing cap shaft provides an inlet passage fluidically connected with the inlet opening of the inner coolant tube of the cooling cartridge for leading the coolant from a main coolant input to the internal coolant duct,

wherein the closing cap shaft provides at least one outlet passage fluidically connected with the at least one outlet opening of the outer coolant sleeve of the cooling cartridge for leading the coolant from the plurality of coolant channels to a main coolant output, and

wherein the cooling cartridge is a polymer cartridge and the closing cap shaft comprises at least one lubrication path that fluidically connects the at least one outlet passage with a first bearing arrangement for lubricating the first bearing arrangement.

2. The electric machine cooling system of claim 1 , wherein the inner coolant tube and the outer coolant sleeve are separate components that are attached to each other by sealing arrangements.

3. The electric machine cooling system of claim 1 , wherein the coolant channels are formed on an outer circumferential surface of the outer coolant sleeve as radially open coolant channels, wherein the coolant channels are enclosed by the outer circumferential surface of the outer coolant sleeve and an inner circumferential surface of the inner hollow shaft.

4. The electric machine cooling system of claim 1 , wherein the cooling cartridge is rotatably supported on a housing via the inner hollow shaft of the inner rotor.

5. The electric machine cooling system of claim 1 , wherein an insertion portion of the closing cap shaft extends into the inner hollow shaft and is attached to the inner hollow shaft so as to be rotatable with the inner rotor about the axis of rotation.

6. The electric machine cooling system of claim 1 , further comprising a coolant input cylinder arranged inside and coaxial to the closing cap shaft,

wherein at least one of:

(i) an inner cavity of the coolant input cylinder provides the inlet passage, or

(ii) the at least one outlet passage is provided between the coolant input cylinder and the closing cap shaft.

7. The electric machine cooling system of claim 1 , wherein the closing cap shaft comprises a bearing portion that provides a bearing surface for the first bearing arrangement for rotatably mounting the cooling cartridge and the inner rotor.

8. The electric machine cooling system of claim 1 , wherein the inner hollow shaft comprises an end portion that provides a further bearing surface for a second bearing arrangement for rotatably mounting the cooling cartridge and the inner rotor.

9. The electric machine cooling system of claim 1 , wherein the inner rotor is provided with permanent magnets.

10. The electric machine cooling system of claim 1 , wherein the outer stator is cooled in addition to the inner rotor.

11. A method for cooling an electric machine, the method comprising the steps of:

providing an electric machine cooling system according to claim 1 ;

introducing a coolant into an inlet opening of an inner coolant tube of the cooling cartridge,

leading the coolant through an internal coolant duct of the inner coolant tube from the inlet opening of the inner coolant tube to a closed dead-end of the cooling cartridge,

leading the coolant from the internal coolant duct through at least one connection channel arranged in a region of the closed dead-end into a plurality of coolant channels of an outer coolant sleeve, the outer coolant sleeve being arranged between the inner coolant tube and the inner rotor, and

leading the coolant through the plurality of coolant channels from the at least one connection channel to at least one outlet opening of the outer coolant sleeve.

12. The method of claim 11 , wherein the coolant channels are formed on an outer circumferential surface of the outer coolant sleeve as radially open coolant channels that are enclosed by the outer circumferential surface of the outer coolant sleeve and an inner circumferential surface of the inner hollow shaft, wherein the coolant is in direct contact with the outer circumferential surface of the outer coolant sleeve and the inner circumferential surface of the inner hollow shaft when flowing through the coolant channels.

13. The electric machine cooling system of claim 1 , wherein the inner rotor is configured as an interior permanent magnet type rotor.

Assignments (2)

Priority Claims (1)

Continuity (1)

References Cited (13)