Pumps – Motor driven – Pump within rotary working member
Reexamination Certificate
1999-07-09
2001-04-10
Thorpe, Timothy S. (Department: 3746)
Pumps
Motor driven
Pump within rotary working member
C417S423100, C417S423700, C415S010000
Reexamination Certificate
active
06213734
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a delivery unit for motor fuel of the species defined in the preamble of claim
1
.
The present invention relates to motor fuel delivery unit for delivering motor fuel and, more particularly, to a motor fuel delivery unit comprising a delivery pump having a housing provided with a pump chamber and an impeller wheel arranged in the pump chamber and an electric motor for driving the delivery pump. The electric motor comprises a stator, a rotor, an armature winding and permanent magnets.
2. Prior Art
With a known delivery unit of this type for delivering motor fuel from a motor fuel reservoir to an internal combustion engine of a motor vehicle (WO 95/25885), the delivery pump and the electric motor for driving it are arranged next to each other in a housing. The impeller wheel, which is equipped with vanes or blades arranged around its periphery, is attached to the shaft of the rotor. The rotor has an armature winding arranged in grooves provided in it for the armature winding. The stator is equipped with permanent magnet segments. The current supply to the armature winding is provided by a commutator or reversing switch seated on the rotor shaft and two current brushes resting radially under spring pressure on the commutator.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved fuel delivery unit for motor fuel of the above-described kind, which is simpler and more compact.
This object and others, which will be made more apparent hereinafter, are attained in a motor fuel delivery unit for delivering motor fuel comprising a delivery pump and an electric motor for driving the delivery pump. The delivery pump has a housing provided with a pump chamber and an impeller wheel arranged in the pump chamber. The electric motor comprises a stator, a rotor, an armature winding and permanent magnets. The stator receives either the armature winding or the permanent magnets. The permanent magnets are arranged on or included in the rotor when the armature winding is received by the stator or the armature winding is arranged on the rotor when the stator receives the permanent magnets.
According to the invention the electric motor is brushless and consists of the impeller wheel of the delivery pump. The stator has an inner ring face consisting of a peripheral wall of the pump chamber. This peripheral wall of the pump chamber bounds the impeller wheel radially and is radially spaced from it.
The delivery unit for motor fuel in accordance with the invention has the advantage that a very simple and compact construction, which can be provided with small production outlay, is achieved by combining the rotating elements of the delivery unit, i.e. the impeller wheel of the delivery pump and the rotor of the electric motor, into a single element. It is in particular possible to embody the delivery unit very flat, i.e. with extremely small axial dimensions. The exterior diameter of the delivery unit which increases in this case, together with the conventional embodiment of the delivery unit, does not represent a disadvantage, but opens the possibility for additional steps for improving the efficiency of the delivery unit. Because the commutator and the current brushes are omitted, wear of the brushes no longer occurs, so that the service life of the delivery unit is increased. When the electric motor is designed as a DC-motor, the required commutation of the current in the stator winding is performed electronically.
In accordance with a preferred embodiment of the invention, the cylinder-shaped pump chamber is delimited by two radially extending lateral walls, which are axially spaced apart, and a peripheral wall, which connects the two lateral walls with each other along their circular periphery. The impeller wheel is placed with clearance in respect to the lateral walls, and the interior surface of the stator formed by riveted armature stampings constitutes the peripheral wall of the pump chamber. The impeller wheel has a plurality of radial impeller wheel vanes, which are spaced apart from each other in the circumferential direction, delimit axially open vane chambers between each other and are connected with each other by means of an outer ring. The permanent magnets are fastened on the outer ring, and if the the delivery unit is made of plastic, they are preferably made of plasto-ferrite materials.
In accordance with an advantageous embodiment of the invention, a groove-like side channel, which is open toward the pump chamber, is formed in each lateral wall of the pump chamber concentrically in relation to the impeller wheel axis, and has an interrupter strip remaining between the side channel end and the side channel start in respect to the flow direction. The side channel start of at least one side channel is in connection with an intake opening, and the side channel end is in connection with a pressure outlet, wherein the axes of the inflow and outflow channels form the intake opening and are either axially or preferably radially oriented in relation to the pressure outlet. A considerable reduction of the flow losses is achieved by the particularly advantageous inflow and outflow of the motor fuel into, or respectively out of the pump chamber, and the efficiency of the pump is improved by this. In contrast to conventional side channel pumps, the radial inflow and outflow becomes possible without problems because of the increased exterior diameter of the delivery unit based on the structure in accordance with the invention, since in this way sufficient structural space is provided in the radial direction for housing appropriate inflow and outflow channels.
REFERENCES:
patent: 3572982 (1971-03-01), Kozdon
patent: 5601398 (1997-02-01), Treiber et al.
patent: 5678306 (1997-10-01), Bozeman, Jr.
patent: 5949171 (1999-09-01), Horski et al.
patent: 09131038 (1997-05-01), None
patent: WO 95/25885 (1995-09-01), None
Dobler Klaus
Huebel Michael
Imhof Ernst
Gray Michael K.
Robert & Bosch GmbH
Striker Michael J.
Thorpe Timothy S.
LandOfFree
Motor fuel delivery unit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Motor fuel delivery unit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Motor fuel delivery unit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2552371