ELECTRIC OIL PUMP, IN PARTICULAR FOR A MOTOR VEHICLE

Abstract

An oil pump, in particular an electric or electromotive auxiliary pump for a motor vehicle, having a housing having an inlet on the admission side and an outlet on the pressure side, in addition to a pump rotor which is inserted in the housing such that it can rotate about an axis, and having at least one rotor part, a flexible housing component which is in the form of an elastic press plate and which extends over the cross-sectional surface of the pump rotor. The flexible pressure plate is maintained, in an advantageous manner, in the edge area of the second housing parts.

Claims

1. An oil pump comprising: a housing having an inlet on a suction side and an outlet on a pressure side; and a pump rotor arranged in the housing such that the pump rotor is rotatable about an axis; at least one rotor part; and a flexible housing component in the form of an elastic pressure plate that extends over a cross-sectional area of the pump rotor.

2. The oil pump according to claim 1, wherein the housing has a first housing part as the housing base body, which accommodates the pump rotor, and a second housing part as the housing cover, wherein the flexible pressure plate is held and/or clamped with its outer edge between the housing parts.

3. The oil pump according to claim 1, wherein a pressure chamber is provided on an outer side of the flexible pressure plate situated opposite the pump rotor, and wherein the pressure chamber is in connection with the pressure side of the pump on the outlet side.

4. The oil pump according to claim 3, wherein the pressure chamber is formed in an axial direction between the flexible pressure plate and the housing cover.

5. The oil pump according to claim 1, wherein a movably mounted rigid side plate having a passage opening aligned with the outlet on the pressure side is arranged between the flexible pressure plate and the pump rotor.

6. The oil pump according to claim 5, wherein the passage opening of the side plate is circular-arc shaped.

7. The oil pump according to claim 1, wherein the flexible pressure plate has a bead-like formation which is open towards the pump rotor and is aligned with the pressure-side outlet or at least partially overlaps the passage opening provided in the side plate, and/or wherein the flexible pressure plate has an opening collar of a shaft feedthrough that is directed towards the pump rotor.

8. The oil pump according to claim 1, wherein the flexible pressure plate has an annular, circumferential, bead-like formation in an area of its outer circumference, which is open towards the pump rotor.

9. The oil pump according to claim 8, wherein the pressure chamber extends in a radial direction between the annular circumferential formation and the opening collar of the flexible pressure plate.

10. The oil pump according to claim 1, wherein the housing has a sleeve-like shaft feedthrough with a bearing sleeve, which is disposed therein, for mounting and passage of a motor shaft of an electromotor to the pump rotor and wherein, on the housing side of the pump rotor situated opposite the shaft feedthrough, a shaft receiver or a bearing sleeve is disposed therein for the mounting of the motor shaft.

11. The oil pump according to claim 2, wherein the pressure-side outlet is inserted into the housing cover and the suction-side inlet is inserted into the bottom side of the housing base body.

12. The oil pump according to claim 1, wherein the pump rotor is a gear set with an internal gear ring eccentrically mounted in the housing and with an external gear ring accommodating the internal gear ring, which is centrally mounted in the housing.

13. An oil pump, in particular an electric or electromotor-driven auxiliary pump for a motor vehicle, the oil pump comprising: a housing having a suction-side inlet and a pressure-side outlet; a pump rotor arranged rotatably about an axis in the housing, the pump rotor having at least one rotor part; an elastic pressure plate that extends over a cross-sectional area surface of the pump rotor; and a side plate arranged between the flexible pressure plate and the pump rotor having a passage opening that is aligned with the pressure-side outlet.

14. The oil pump according to claim 1, wherein oil pump is an electric or electromotor-driven auxiliary pump for a motor vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0027] FIG. 1 is a perspective pressure-side view of an electrical or electromotor-driven oil pump having a housing shown in partial section and partially transparent, having therein a fixed side plate between an elastic pressure plate (diaphragm) and a gear set as a pump rotor (G-rotor);

[0028] FIG. 2 is a representation according to FIG. 1, of the oil pump in a perspective suction-side view, with a view to the gear set (G-rotor);

[0029] FIGS. 3 and 4 illustrate the oil pump in a perspective view, with a view to a suction opening (inlet) on the housing bottom side or to a shaft-side pressure opening (outlet);

[0030] FIG. 5 is an axial sectional view of the oil pump;

[0031] FIG. 6 is a section VI of FIG. 5 in a larger scale with a view to a peripheral rim of the pressure plate in the housing and to a pressure chamber between a shaft feedthrough and a circumferential bead contour; and

[0032] FIG. 7 is a sectional view along the line VII-VII in FIG. 5, with a view to the pressure side of the elastic pressure plate (diaphragm).

DETAILED DESCRIPTION

[0033] According to FIGS. 1 to 4, the oil pump 1 has a pump housing 2 formed, for example, of steel or aluminum, in the form of a shell-like (first) housing part, which is subsequently referred to as the housing base body 2a, and a cover-like housing part, hereinafter referred to as housing cover 2b. The housing base body 2a forms a cylindrical housing wall 3, that is to say, in particular, a cylindrical interior space 4 and a housing base 5, which is hereinafter also referred to as a first side plate, as well as a housing opening 6 axially opposite it. A bottom-side bearing opening 7, which is extended in the manner of a collar, serves in conjunction with a bearing sleeve 8a seated therein for the sliding bearing of a motor shaft 9 of an electric motor. A corresponding sleeve-like shaft feedthrough 10 with a bearing sleeve 8b, which in turn is seated therein, in the housing cover 2b serves for the passage of the motor shaft 9 from the outside into the housing 2 and there via a pump rotor 11 into the bearing opening 7.

[0034] In connection with FIG. 5, it can be seen that a gear set with an internally toothed external gear ring 11a and with an externally toothed internal gear ring 11b is inserted as a pump rotor 11 into the housing interior 4 of the housing base body 2a. In each rotational position relative to the external toothed ring 11a, the external toothing 12 of the internal gear ring 11b is partially intermeshed between or in the internal toothing 13 of the former. Some of the wavy teeth of the external toothing 12 are thereby inserted in the again wavy tooth gaps of the internal toothing 13 of the external gear ring 11a and vice versa, while other teeth of the external toothing 12 of the internal gear ring 11b can slide along a peripheral portion of the internal toothing 13 of the external gear ring 11a without tooth engagement. Such a gear set (11a, 11b) as a pump rotor 11 is also referred to as a gerotor (G-rotor).

[0035] As indicated in FIG. 5 by means of the dashed lines A.sub.i and A.sub.a, the axis A.sub.i is radially spaced apart (eccentric) from the central axis (center/symmetry axis) A.sub.a, which forms the axis of rotation of the external gear ring 11a, as an axis of rotation of the internal gear ring 11b—and thus the shaft feedthrough 10—which internal gear ring is, for example, positively joined with the motor shaft 9. To receive the shaft 10, the internal gear ring 11b has a, for example, star-shaped contoured joining opening 14. The latter is aligned with the shaft opening 10 of the housing base body 2a.

[0036] In contrast to the external gear pump, in the case of such an internal gear ring or gear ring pump as a special type of gear pump, the internal gear ring 11b thus runs as a driving gear eccentrically in the external gear ring (outer toothed ring) 11a. In the case of this gear ring pump, the medium is conveyed between the tooth gaps of the gear rings 11a and 11b by the displacement space which is changing in the volume. In other words, in this gear pump, which is also referred to as a crescent pump, the medium to be conveyed is conveyed in the spaces between the tooth gaps of the two gear rings (gear wheels) 11a and 11b, wherein the teeth are sealed by the crescent between the inwardly directed inner teeth of the external gear ring 11a and the outwardly directed outer teeth of the internal gear ring 11b. In the case of the illustrated gear ring pump as oil pump 1, the external gear ring 11a has exactly one tooth more than the internal gear ring 11b (trochoid toothing).

[0037] The housing base body 2a is closed with the housing cover 2b. The pressure-side pump outlet (pressure opening or pressure outlet) 16 is provided in the housing cover 2b (FIGS. 3 and 4), while the suction-side pump inlet (suction openings) 15 is introduced into the housing bottom 5 of the housing base body 2a.

[0038] Within the housing 2, a side plate 17, which is penetrated by the motor shaft 9, is fixed to the edge side of the housing opening 6 of the housing base body 2a. This, preferably rigid, side plate 17 is located on the edge or outer circumference in an annular notch 18 of the housing base body 2a. The rigid side plate 17 has a circular-arc-shaped passage opening 19 extending over a circumferential section. Between this side plate 17 and the housing cover 2b, a flexible pressure plate 20, hereinafter also referred to as a diaphragm, is inserted into the housing 2. This preferably circular pressure plate 20 is clamped with its outer edge 20a between the housing base body 2a and the housing cover 2b on the opening or edge side and is therefore also fixed to the housing. By means of the flexible pressure plate 20, in particular temperature-dependent partial expansions of housing or pump are reduced and/or compensated for.

[0039] In the region of the passage opening 19 of the side plate 17, a bead-like, indented outlet channel 21 is formed into the flexible pressure plate 20, which outlet channel is aligned with the circular-arc-shaped passage opening 9 of the side plate 17 with respect to its shape and location (position), covering said side plate but leaving a passage 22 (FIG. 7). This passage 22 is aligned with the cover-side pump outlet 16 which can be seen in FIG. 4.

[0040] An opening collar 22, which is pulled out in the direction of the housing cover 2b, is formed or shaped in the region of the shaft feedthrough 10, i.e., aligned with the latter, into the pressure plate 20 at its shaft feedthrough 20b. In the region of the outer edge 20a or outer circumference of the flexible pressure plate 20, a bead-like, annular circumferential formation 23 is likewise inserted in the direction of the housing cover 2b. Between this formation 23 and the opening collar 22, a pressure chamber (clearance/pressure equalization chamber) 24 is formed. A fluid channel (housing channel) 26 to this pressure chamber 24, which is indicated by dashed lines, can be inserted into the housing wall 25 of the housing 2. A partial flow of the conveyed medium (oil) M from the inlet-side suction side can pass through said fluid channel, between the flexible pressure plate 20 and the housing cover 2b, into the pressure chamber 24.

[0041] In viewing the section shown in FIG. 6 and the cross-section in FIG. 7, the flexible pressure plate (diaphragm) 23 which extends transversely to the axial direction A of the oil pump 1 in the radial direction R and thus practically across the entire housing cross-sectional area, and the pressure chamber (clearance/pressure chamber, pressure equalization space) 24 formed between the diaphragm and the housing cover 2b can be seen. In these, oil M can be introduced via the fluid channel 26, i.e., a partial flow of the oil M conveyed through the pump 1. When the pump is operated, this results in a force action F.sub.a on the outer side of the flexible pressure plate 23 situated opposite the gear set 11a, 11b. This pressure force F.sub.a acts counter to the oil compressive force prevailing in the pump interior 4 and can thus produce at least some pressure equalization.

[0042] The invention is not limited to the embodiments described above. Rather, other variants of the invention can also be derived from those skilled in the art without departing from the scope of the invention. In particular, all the individual features described in connection with the exemplary embodiments can also be combined with one another in another manner without departing from the subject matter of the invention.

[0043] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.