Fluid pumping system

Abstract

Fluid pumping system for a vehicle with an internal combustion engine, the fluid pumping system comprising: a housing; an electric motor; a planetary gear with a first member that can be driven by the internal combustion engine, a second member driven by the electric motor, and a third member; and a pump driven by the third element of the planetary gear set, the housing being closed by a pump flange and a pulley with pulley cover, wherein at least the pulley and/or a ring gear disposed in the pulley is made of plastic.

Claims

1. A fluid pumping system for a vehicle with an internal combustion engine, the fluid pumping system comprising: a housing; an electric motor; a planetary gear set with a first member that can be driven by the internal combustion engine, a second member driven by the electric motor, and a third member; and a pump driven by the third element of the planetary gear set, the housing being closed by a pump flange and a pulley with pulley cover, wherein the pulley forms a contact surface which, together with an axially extending area of the housing, forms a receptacle for a bearing.

2. The fluid pumping system according to claim 1, wherein the pulley is made of sheet metal.

3. The fluid pumping system according to claim 1, wherein the ring gear is made of plastic and can be pressed into the pulley.

4. The fluid pumping system according to claim 1, wherein the pulley and the ring gear are made in one piece from plastic.

5. The fluid pumping system according to claim 1, wherein the pulley forms a mounting space for a planetary gear.

6. The fluid pumping system according to claim 1, wherein the pump is sealed from the electric motor by means of radial shaft seals.

7. The fluid pumping system according to claim 1, wherein an impeller of the pump is supported by a double-row ball bearing.

8. The fluid pumping system according to claim 1, wherein a shaft is supported by a single bearing point.

9. The fluid pumping system according to claim 1, wherein the pulley and/or a ring gear disposed in the pulley is made of plastic.

10. A fluid pumping system for a vehicle with an internal combustion engine, the fluid pumping system comprising: a housing; an electric motor; a planetary gear set with a first member that can be driven by the internal combustion engine, a second member driven by the electric motor, and a third member; and a pump driven by the third element of the planetary gear set, the housing being closed by a pump flange and a pulley with pulley cover, wherein the ring gear is connected to the pulley cover in a positionally secure manner via at least one recess and/or a nose.

11. The fluid pumping system according to claim 10, wherein the pulley and/or a ring gear disposed in the pulley is made of plastic.

Description

DRAWINGS

(1) The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. The disclosure is described below by way of example, with reference to the attached drawings.

(2) FIG. 1 shows a schematic diagram of the exemplary embodiment,

(3) FIG. 2 shows an overhead view of the planetary gear,

(4) FIG. 3 shows a section through a pulley,

(5) FIG. 4 shows a view of the fluid pumping system.

(6) Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

(7) Example embodiments will now be described more fully with reference to the accompanying drawings.

(8) FIG. 1 shows the schematic structure of the fluid pumping system 1 consisting of a pump housing 3 which is closed by a pump flange 4. The fluid pumping system 1 has three main components. The pump 14 of the fluid pumping system is disposed on the right-hand side along a shaft 2. In the centre is an electric motor 20, being a BLDC motor. This has a stator 21 and a rotor 22 designed as a hollow shaft. Inside the stator is a sealing wall 4a of a pump flange 4, which seals the electric motor 20 against moisture. A pulley 5 is disposed on the left-hand side in the end area 2a of the shaft 2. The pulley 5 is designed to contain a reduction gear in the form of a planetary gear 7. The pulley 5 is a component that is bent from a piece of sheet metal. It has an outer circumference 5a, which serves as a friction surface for a belt drive via an internal combustion engine. The pulley 5 furthermore has an inwardly reduced circumference 5b, wherein an installation space 5c is formed to accommodate the planetary gear 7. With a further circumferential reduction to a circumference 5d, the pulley forms a contact surface 5e for a bearing 16. In this embodiment, the pulley has a smooth outer circumference 5a, but a design with a textured surface for a textured drive belt is also conceivable. A ring gear 10 for the planetary gear 7 is pressed into the installation space 5c of the pulley 5.

(9) The ring gear 10 is made of a plastic material that is pressed into the pulley. A planetary gear cover 6, also made of sheet metal, serves to cover the planetary gear 7. The planetary gear cover has one or more recesses 13 which are designed to engage with the nose(s) 15 of the plastic ring gear 10.

(10) When the fluid pump is driven by the internal combustion engine via the pulley 5, the pulley 5 rotates with the pressed-in ring gear 10 and the planetary gear cover 6. The planetary gear 7 further consists of a planet carrier 9 on which the planet 11 is rotatably mounted, and a sun gear 8. The sun gear 8 is connected to the shaft 2 in a rotationally fixed manner.

(11) Together with an axially extending area 3a of the pump housing 3, the pulley also forms a mounting space 17 for the bearing 16, which here is a double ball bearing. This bearing arrangement of the pulley by means of a double-row ball bearing on the housing provides power transmission via the housing structure rather than via the functional drive of the fluid pumping system 1, i.e. via the planet carriers 9, the shaft 2 and the bearings of the pump. This reduces the load on the mechanical sealing of the water pump as it improves concentricity, therefore radial shaft seals 19 can be used instead of a conventional mechanical end-face seal. The use of a double-row ball bearing 18 for the impeller bearing of the fluid pump saves axial installation space compared to a bearing assembly consisting of a ball bearing with a needle bearing as used in the past. The shaft 2 is supported by a single bearing point 23.

(12) In an alternative embodiment, the pulley 5 is not made from sheet metal, but is injection moulded from plastic together with the ring gear 10.

(13) The fluid pumping system can be operated by means of the coupled mechanical and electrical drive. Mechanical drive is provided by a belt drive and the pulley 5, while electrical drive is provided by the BLDC motor. The drive function is coupled to the superimposing gear, i.e. the planetary gear 7, which couples the belt drive and the electric drive directly to one another.

(14) The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are inter-changeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.