Pump assembly for recirculating a cooling fluid of a heat engine

Patent metadata

Field	Value
Publication number	US-11085449-B2
Application number	US-201515305159-A
Country	US
Kind code	B2
Filing date	Apr 30, 2015
Priority date	Apr 30, 2014
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

Pump assembly for recirculating a cooling fluid of a heat engine, comprising:a pump body, an impeller driven by a driven shaft and inserted in a chamber of the circuit for recirculating the cooling fluid of the heat engine;at least a reversible friction clutch, adapted to transmit the motion from motion generating means, coupled to the motor shaft of the vehicle, to the driven shaft,an electric motor to drive said driven shaft independently of the heat engine; whereinsaid electric motor and said friction clutch are arranged in an axially external position with respect to the motion generating means of the clutch.Preferably, said electric motor is axially opposed to the friction clutch with respect to the motion generating means, and is axially adjacent to the chamber of the impeller in the axial direction.

First claim

The invention claimed is:

1. Pump assembly for recirculating a cooling fluid of a heat engine, comprising:
a pump body defining a pulley sized and configured to be rotationally driven by the heat engine, the pump body housing:
an impeller driven by a driven shaft, the impeller being coupled to a cooling circuit for recirculating the cooling fluid of the heat engine;
at least one clutch sized and configured to connect/disconnect said pulley to/from said driven shaft; and
an electric motor coupled to said driven shaft to rotationally drive the impeller when said clutch is disconnected;

characterized in that
said pump body defines a longitudinal development having a radial narrowing portion axially disposed between said electric motor and said clutch, the pulley being axially coextensive with and disposed about the radial narrowing portion and entirely between the electric motor and the clutch,
wherein the longitudinal development of the pump body has, on each side of the narrowing portion, a larger portion having a larger radial extent than the narrowing portion, said larger portions housing said electric motor and said clutch, respectively, and the pulley has a smaller maximum radial extent than both said larger portions, said electric motor having a larger radial extent than the maximum radial extent of the pulley.

2. Pump assembly according to claim 1 , characterized in that one of said larger portions, which is intended to be coupled to said heat engine, defines a chamber of the impeller, and wherein said electric motor is housed in said one of said larger portions and is axially adjacent to the chamber of the impeller.

3. Pump assembly according to claim 1 , characterized in that a rotor of the electric motor is coupled to the shaft of the impeller by means of a rotor bell, rotationally integral with the shaft, and in that a sensor for detecting the rpm of the impeller is arranged in correspondence with said rotor bell.

4. Pump assembly according to claim 1 , wherein the electric motor has a stator arranged in a radially external position with respect to the rotor.

5. Pump assembly according to claim 1 , characterized in that it comprises a cooling circuit of the electric motor coupled to the cooling circuit for recirculating the cooling fluid of the heat engine, the cooling circuit of the electric motor comprising at least a delivery channel and a return channel of the cooling fluid from and/or to a chamber of the impeller.

6. Pump assembly according to claim 5 , wherein the electric motor has a stator, the pump body is sized and configured to support the stator, and the cooling circuit of the electric motor is formed in the pump body adjacent the stator of the electric motor.

7. Pump assembly according to claim 1 , wherein said pulley is in a single piece with a first of said larger portions that houses said clutch, mounted on a bearing keyed on a second of said larger portions that houses said electric motor; said first larger portion defining a rotor of the clutch.

8. Pump assembly according to claim 1 , characterized in that said clutch is of the electromagnetic type, and comprises: a fixed electromagnet, a flow element for concatenating a magnetic flow and a keeper, axially arranged opposite to the flow element with respect to the electromagnet.

9. Pump assembly according to claim 7 , wherein the clutch includes an electromagnet and a keeper, the rotor of the clutch has an axially fixed annular plate arranged on the opposite side of the keeper with respect to the electromagnet and fixed to the rotor by means of axial screws holding axial bushes which form a guiding element to an axial translation of the keeper.

10. Pump assembly according to claim 7 , characterized in that a sleeve is mounted on said driven shaft, rotationally integral and axially movable with respect to the shaft, a circular flange being integral with the sleeve and being axially interposed between a keeper and a fixed plate of the clutch.

11. Pump assembly according to claim 10 , characterized in that a friction material is applied on the opposite faces of the annular flange.

12. Pump assembly according to claim 8 , characterized in that it comprises a plurality of springs axially contained in corresponding seats of an axial extension of the rotor of the clutch against which they react and acting on the keeper by pushing it in the axial direction in the direction of the detachment of the flow element and towards a fixed plate of the clutch.

13. Pump assembly according to claim 1 , characterized in that it comprises a friction and an excitation clutch.

14. Pump assembly according to claim 13 , characterized in that the excitation clutch comprises a fixed electromagnet, an element for concatenating the flow constrained to a rotor by means of screws, a keeper integral with the annular flange by means of an elastic membrane which rotationally constrains the keeper, but allows the axial movement of the latter.

15. Pump assembly according to claim 1 , wherein the clutch includes an electromagnet, the electromagnet is controlled by means of the PWM (Pulse Width Modulation) technique.

16. Pump assembly for recirculating a cooling fluid of vehicles according to claim 8 , wherein the electromagnet controlling the clutch comprises at least two coils, powered in order to generate an initial current in the coils to determine a high returning force of the keeper towards the flow element for concatenating the flow, and a subsequent holding current to determine a reduced holding force of the keeper against the flow element for concatenating the flow.

17. Pump assembly according to claim 16 , characterized in that the at least two coils are one more powerful and one less powerful than the other and/or in that one activation of the coils is selective.

18. Pump assembly according to claim 17 , characterized in that the two coils are connected to each other in parallel.

19. Pump assembly according to claim 17 , characterized in that in order to determine said initial returning force of the keeper the more powerful coil and/or both coils are excited, and in order to determine said reduced holding force of the keeper once its return has occurred, one single coil is excited, for example the less powerful coil.

20. Pump according to claim 16 , characterized in that the two coils have the same power and are connected by a power supply circuit which can be switched from parallel to series and vice versa, and in that, in order to determine said initial returning force of the keeper, the two coils are connected in parallel and excited and, once the return has occurred, the two coils are connected in series and excited, to determine said reduced holding force of the keeper.

Assignees

• Fpt Ind Spa
• Baruffaldi Spa

Inventors

• Modica Massimiliano
• Turco Mariano

Classifications

• F04D15/0027

  Varying behaviour or the very pump (F04D15/0055 and F04D29/46 take precedence) · CPC title

• F16D27/112

  with flat friction surfaces, e.g. discs · CPC title

• F04D13/021 Primary

  containing a coupling · CPC title

• F01P5/12

  Pump-driving arrangements · CPC title

• F01P5/10 Primary

  Pumping liquid coolant; Arrangements of coolant pumps · CPC title