Internal gear machine for reversed operation in a closed hydraulic circuit

Information

  • Patent Grant
  • 6419471
  • Patent Number
    6,419,471
  • Date Filed
    Friday, March 23, 2001
    23 years ago
  • Date Issued
    Tuesday, July 16, 2002
    22 years ago
Abstract
The invention relates to an internal gear machine for reversed operation in a closed circuit comprising an outer-toothed pinion, an inner-toothed ring gear meshing with the pinion; a housing; a filing that fills the sickle-shaped space between the pinion and the ring gear; the filling comprises two identical filler pieces; a stop pin is provided that is mounted in the housing and against which the filler pieces are supported by their front faces; the housing has two pressure lines and a drain outlet; the filler pieces are symmetrically disposed relative to a plane (symmetrical plane) extending through the center points of the pinion and the ring gear; the two pressure lines are located on both sides of the symmetrical plane viewed in axial direction.
Description




BACKGROUND OF THE INVENTION




The invention relates to an internal geared wheel machine, in particular an internal geared wheel pump. Such machines are known from numerous publications, for example DE 41 04 397 A1.




WO 95/12070 describes an internal geared wheel machine which has a longitudinally divided filling member.




Problems always arise when machines of the described type are to be driven in reversing operation, and when the pressure range changes. Thus, for example, there are numerous instances of application in which it is desired to operate an internal geared wheel pump both clockwise and counterclockwise. So far there has not yet been any solution for the case when such a pump is to be driven in a closed system.




SUMMARY OF THE INVENTION




Underlying the invention is the problem of indicating an internal geared wheel machine that can be driven in both rotation directions, and which can be installed into a closed system, and namely when the position of the pressure range in the pump changes.




This problem is solved by the features of claim


1


.











DESCRIPTION OF THE DRAWINGS




The invention is explained in detail with the aid of the drawing. Therein there is represented in detail the following:





FIG. 1

shows in axially perpendicular section view an internal geared wheel pump;





FIG. 2

a circuit with an internal geared wheel according to the invention.











DETAILED DESCRIPTION OF THE INVENTION




The internal geared wheel pump shown in

FIG. 1

comprises as essential components a pinion


1


with an external toothing, a hollow wheel


2


with an internal toothing, a filling composed of two filling members


3


,


4


, a stop pin


5


, and a housing


6


.




Pinion


1


is eccentrically borne with respect to hollow wheel


2


. See the midpoints M


1


of the pinion and M


2


of the hollow wheel. Through the two midpoints M


1


, M


2


there is laid a dot-and-dash straight line. This designates a plane of symmetry, the significance of which will further be explained below.




The sickle-shaped space between the pinion


1


and the hollow wheel


2


is filled by a filling element. The filling/lining comprises the two filling members


3


,


4


. The stop


5


is borne in the housing


6


with a certain amount of play. As one sees, the stop has two support surfaces


5


.


1


,


5


.


2


. The face surfaces of the two filling members


3


,


4


are supported against the support surfaces


5


.


1


,


5


.


2


.




The two filling members


3


,


4


, furthermore, are divided lengthwise in a manner known per se. They are composed, therefore, of an inner part


3


.


1


,


3


.


2


, respectively


4


.


1


,


4


.


2


. The filling members


3


,


4


could just as well, however, consist of a single part.




The housing has two pressure connections


6


.


1


,


6


.


2


. The two pressure connections lie on both sides of the axis of symmetry


7


. The housing further has a leakage outlet


6


.


3


. In the present case, this lies exactly in the plane of symmetry


7


.




Important also is the following feature. The arrangement is made in such a way that the two filling members


3


,


4


lie symmetrically to the plane of symmetry


7


. Also, the stop pin


5


is arranged in such manner that the plane of symmetry


7


runs through it, and divides it into two parts symmetrical to each other. As one sees, the plane of symmetry


7


runs through the tip of the stop pin


5


that is formed from the two support surfaces


5


.


1


,


5


.


2


.




As one further sees, the housing


6


has recesses


6


.


1


.


1


,


6


.


2


.


1


,


6


.


3


.


1


. These are connected to the respective pressure connections


6


.


1


,


6


.


2


, respectively to the leakage outlet


6


.


3


.




In the circuit plan represented in

FIG. 2

, one perceives a pump


10


according to the invention. The pump


10


is a component of a closed circulation system. One perceives, further, a hydraulic unit


11


, comprising a double-acting piston


11


.


1


and a cylinder


11


.


2


. The piston


11


.


1


is slidable in both directions in the cylinder


11


.


2


, depending on which one of the two lines


12


,


13


the cylinder is acted upon with a pressure medium by means of the pump


10


. Depending on the direction of rotation of the pump


10


, the pressure medium is conveyed either into line


12


or into line


13


.




One perceives a further pump


14


, a pressure regulator


15


, a line


16


, a line


17


, as well as a supply container


18


.




In the internal geared wheel pump represented in

FIG. 1

, there necessarily occurs a leakage. The leakage amount emerges through the leakage outlet


6


.


3


in FIG.


1


. This amount must be steadily replaced, for this there serves the pump


14


. This latter takes pressure medium—in general an oil—out of the supply container


18


. It conveys it through the line


16


. The pressure regulator


15


provides that the medium pressure does not exceed a certain upper value. If the medium pressure exceeds such a value, then the pressure regulator opens, so that a certain amount of pressure medium again flows over the line


17


and back into the supply container


18


. The oil regulated up to the upper value flows onward in line


16


and passes through one of the two non-return valves


19


and, depending on the direction of rotation, into one of the two lines


12


,


13


and therewith onto one of the two sides of the piston


11


.


1


.




while the internal geared wheel pump


10


of the invention conveys up to high pressures, such as for example 300 bar, the pump


14


as feed pump needs attain only substantially lower pressures, for example 10 bar.



Claims
  • 1. An internal geared wheel machine for reversing operation in closed circulation, said machine comprising:a housing having two pressure connections and a leakage outlet; an externally toothed pinion disposed in said housing; an internally toothed hollow wheel disposed in said housing, said hollow wheel meshing with said pinion; a filling that fills a sickle-shaped space between sad pinion and said hollow wheel, said filling comprising two like-construction filling members; and a stop pin disposed in said housing, said stop pin having face surfaces against which said filling members are supported; said filling members being arranged symmetrically to a plane of symmetry that runs through respective midpoints of said pinion and wheel; said two pressure connections lying on respective opposite sides of said plane symmetry.
  • 2. The internal geared wheel machine of claim 1 wherein said leakage outlet lies approximately in the plane of symmetry.
  • 3. The internal geared wheel machine of claim 2 wherein said machine is a component of a closed system.
  • 4. The internal geared wheel machine of claim 1 wherein said machine is a component of a closed system.
Priority Claims (1)
Number Date Country Kind
199 30 910 Jul 1999 DE
PCT Information
Filing Document Filing Date Country Kind
PCT/EP00/06342 WO 00
Publishing Document Publishing Date Country Kind
WO01/02730 1/11/2001 WO A
US Referenced Citations (5)
Number Name Date Kind
3204564 Eltze Sep 1965 A
3525581 Eckerle Aug 1970 A
4392796 Lindtveit Jul 1983 A
4472123 Eckerle et al. Sep 1984 A
5032069 Parsons Jul 1991 A
Foreign Referenced Citations (10)
Number Date Country
353 838 Jun 1922 DE
1 528 947 Sep 1969 DE
1936837 Jan 1971 DE
43 38 875 May 1995 DE
273002 Jun 1927 GB
55-014964 Jan 1980 JP
57-052694 Mar 1982 JP
05-180173 Jul 1993 JP
160365 May 1979 NL
WO 9512070 Mar 1995 WO