CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 U.S. National Phase of International Application No. PCT/EP2018/078806, filed Oct. 19, 2018, which claims the benefit of German Patent Application No. 10 2017 220 156.8, filed Nov. 13, 2017. The entire disclosures of each of the above applications are incorporated herein by reference.

FIELD

The disclosure is related to a method to assemble a water pump with an impeller driven by an electrical machine comprising a housing cap and a volute with an input and an output and a boot hosting a stator and a rotor of the electrical machine and an electronic board mounted at the side apart from the impeller and covered by the cap housing, wherein the stator stack is over molded.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

Generally, water pumps include a stator and rotor. The rotor is in communication with an impeller for moving a fluid. The fluid enters the pump through an inlet in a volute, contacted with an impeller and moved through an outlet in the volute. The rotor and stator are contained with a housing that connects with the volute. Generally, the rotor and stator are separated by a magnetic air gap and the rotor and stator include rare earth metals so that magnetic air gap between the rotor and stator may be bridged so that the rotor is rotated during use and so that the rotor, the stator, or both may be isolated from the fluids during use and continue to operate. However, the use of rare earth metals may be damaged by the fluid such that the rare earth metals may require additional packaging so that damage is prevented.

U.S. Pat. No. 9,360,015 B1 discloses an electric water pump, and more specifically an electric water pump having an improved wet sleeve so that the water pump is free of a housing. The electric water includes a pump rotor having a shaft. A wet sleeve surrounds the rotor and has a cap, a sleeve that houses the rotor, and a seat in communication with the shaft of the rotor so that the seat assists in supporting the shaft a stator. Surrounding the wet sleeve and the rotor is a volute covering an upper portion of the rotor, wet sleeve, and stator. The electric water pump further includes a rubber boot covering a lower portion of the rotor, wet sleeve, and stator and is in communication with the volute forming a cover.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

The objective of the disclosure is to provide a water pump with an optimized design that is able to be assembled in a secure and easy way.

The solution provided is a method to assemble a water pump with an impeller driven by an electrical machine comprising a housing cap and a volute with an inlet and an outlet and a boot hosting a stator and a rotor of the electrical machine and an electronic board mounted at the side apart from the impeller and covered by the cap housing, the boot having a radial extending rim comprising at least slots defined by the following steps: Connecting the volute to the boot by inserting axial hooks in the boot's slots, twisting the volute versus the boot to fix the axial hooks, inserting radial hooks of the cap housing in the same slots.

The mounting is very easy to handle and the device is securely fixed without screwing processes of clamping of the part.

It is an advantage that the axial L-formed hooks are fixed with the smaller arms of the L to the rim of the boot.

It is an advantage that the axial hooks are guided by lugs surrounding the slots, so that the hooks can be inserted quickly too.

The twisting is in direction of the opening of the smaller arms of the L-formed hooks to fix the hooks firmly at the rim of the boot.

It is an advantage that the broadness of the axial hooks and the radial hooks are together as broad as the slot, to be firmly fixed and do not allow radial of axial moves.

The disclosure allows a device assembly with reduced parts and reduced effort. Due to the fact that part are completely over molded the heat transfer is better. This also due to the fact that dimension can be reduced and the weight of the water pump is lower compared to standard die casted pumps. The pump has a high resistance to vibrations.

