DE102015004984A1 - Internal gear pump and vehicle with an internal gear pump - Google Patents

Abstract

The invention relates to an internal gear pump, in particular Trochoidenpumpe, for a vehicle, with a pump housing (3) with a rotor chamber (4) in which, an internal toothing with internal teeth (7a-7g) exhibiting toothed ring (6) is received, which with a eccentrically to the toothed ring (6) mounted and an external toothing with external teeth (12a-12f) having gear (11) is engageable such that at a tooth engagement region (13a) at least one of the external teeth (12a) in a between two internal teeth (7a; 7g), the pump chambers (16) forming volumes between the inner teeth (7a-7g) and the outer teeth (12a-12f) in a, a suction chamber (17) associated rotor chamber area, starting from the tooth engagement region (13a) up to to a Zahnangrenzungsbereich (14a), in which at least one outer tooth (12d) on the head side adjacent to an inner tooth (7d) or is applied, become larger and in one, e in the pressure chamber (18) associated rotor chamber area, starting from the Zahnangrenzungsbereich (14a) to the tooth engagement area (13a) again smaller. According to the invention, at least one relief channel (19) is provided, which forms a flow connection between the tooth engagement region (13a) and the pressure chamber (18).

Description

The invention relates to an internal gear pump, in particular a trochoid pump, according to the preamble of claim 1 and a vehicle, in particular a utility vehicle, with an internal gear pump according to the preamble of claim 15.

Internal gear pumps are used in a variety of ways, for example as resource pumps in vehicles. Such use requires quiet and quiet operation so that no psychoacoustic noise is transmitted to a cab or passenger compartment.

A generic, well-known internal gear or Trochoidenpumpe consists of a pump housing with a cylindrical rotor chamber with a rotatably arranged in the rotor chamber outer rotor with internal teeth. In the outer rotor is a rotationally driven inner rotor with external teeth, with the inner teeth and external teeth meshed trochoidal shaped. The inner rotor has one outer tooth less compared to the inner teeth of the outer rotor. Starting from a reference plane, which runs through the axis of rotation and through a first dead center position and through the center of an opposite second dead center position, in the first dead center position, an outer tooth of the inner rotor engages completely in a tooth interposition area in a tooth space of the outer rotor. In the second opposite Totpunktstellung are each an outer tooth of the inner rotor and an inner tooth of the outer rotor in a tooth adjacency region on the head side together.

In a full revolution of the inner rotor, starting from the reference plane at the first dead center position in the direction of rotation, the pump chambers become larger in a suction chamber formed on the front side of the rotor chamber. Subsequently, after passing through the reference plane at the second dead center position, the pump chambers become smaller again in a pressure space likewise formed on the rotor chamber, so that the fluid sucked and received in the suction chamber in the pump chambers is compressed in the pressure chamber by reducing the pump chambers and pumped out through an outlet opening.

In this generic internal gear pump or trochoid pump the tooth or Trochoidalformen the outer teeth and inner teeth are chosen so that the abrolling tooth surfaces are close together to achieve high pump efficiencies with minimal fluid mechanical losses. However, this has the disadvantage that in the transition of the pressure chamber to the suction chamber volumes of the fluid to be delivered are included, which can escape only by pinching between tooth flanks of the rotors in the first dead center. These high-energy flows and associated fluctuations in the drive torque generate an airborne and structure-borne noise emission, which presents itself with a high degree of ripple in the respective spectrum. The inevitable generation of squish flows leads by increasing the drive torque to efficiency losses of the pump and in addition to a significant increase in the sound pressure also to an unpleasant for human hearing expression of psychoacoustic parameters. In addition, a pressure surge is also generated by an impulsive violation of the delivery volume from the suction chamber into the pressure chamber at the second dead center position, which also adversely affects the frequency and tonal spectrum. These noted acoustic drawbacks may limit the scope of such standard trochoidal pumps in spaces coexisting with persons, particularly when used in vehicles where sound reduction and acoustical compatibility is a constant technical challenge.

In contrast, to achieve an acoustic improvement, it is already known ( DE 603 02 110 T2 ) to increase the gap between the tooth tips of the inner rotor and the outer rotor, that is, to execute the Zahnköpfer lower than the tooth shapes would ask for the exact Trochoidenkurve. This reduces the generation of pinch currents of high squish intensity, thereby reducing noise loading depending on the individual design of the modified trochoid curve. However, this potential acoustic advantages is counteracted by the significant disadvantage that, due to the function, fluid volumes are circulated between the pressure chamber and the suction chamber, which is associated with high fluid mechanical losses and a reduction of the pump efficiency.

The object of the invention is to develop a generic internal gear pump so that it can be operated with a high fluid mechanical efficiency and low noise output. Another object of the invention is to propose a vehicle, in particular a commercial vehicle, with such an internal gear pump.

This object is achieved with the features of the independent claims. Advantageous embodiments are the subject of the dependent claims.

According to claim 1, an internal gear pump, in particular Trochoidenpumpe, proposed for a vehicle, with a pump housing with a rotor chamber in which a, an internal toothing with internal teeth exhibiting toothed ring is added. This toothed ring can be brought into engagement with an internal toothed wheel eccentrically mounted with respect to the toothed ring and having external teeth with external teeth such that, relative to a basic or initial position or with respect to a dead center position, at least one of the external teeth in one between two teeth Internal teeth lying inner tooth space rests, in particular form- and contour-fitting rests, wherein the pump chambers forming volumes between the inner teeth and the outer teeth in a, a suction chamber associated rotor chamber area, starting from the meshing area to a, preferably the tooth meshing area opposite, Zahnangrenzungsbereich in which at least an outer tooth abuts or abuts an inner tooth on the head side, grows larger and, in a rotor chamber region assigned to a pressure chamber, starts again from the tooth abutment region up to the tooth engagement region get smaller. In other words, that in a pump actuation pumping chambers forming volumes between the inner teeth and the outer teeth, starting from the, associated with a first dead center tooth engagement region in a, a suction chamber of the pump associated rotor chamber area to one, preferably the tooth engagement region opposite and one second toothing point range associated with, are larger and then become smaller after passing through the Zahnangrenzungsbereiches in a, a pressure chamber associated rotor chamber area up to the meshing area. According to the invention, at least one relief channel is now provided, which forms a flow connection between the tooth engagement region and the pressure chamber, so that a fluid or a squish flow can flow or flow away from the tooth engagement region to the pressure chamber.

Thus, the otherwise critical squish flows forming, trapped volumes are advantageously derived in this area targeted by the at least one discharge channel into the pressure chamber, or can escape in this area squeezed fluid always to the pressure chamber. This discharge into the pressure chamber minimizes crushing losses so that noise generation is minimized accordingly.

However, in contrast to the measure in the prior art, the squish flow derived in the pressure chamber is available with a gap enlargement wider than useful volume, so that no fluid-mechanical losses occur due to the targeted discharge of the squish quantity into the pressure chamber.

The at least one external tooth in the tooth engagement region is preferably located in the inner tooth space such that it is substantially completely or completely received therein, and thus pump chambers with a zero volume or virtually zero volume are formed there. This means that the at least one external tooth in the tooth engagement region preferably rests completely or substantially free of gaps and / or shape and contour in the inner tooth space.

Constructively advantageous, the suction chamber and the pressure chamber are spaced from the tooth engagement region and / or the Zahnangrenzungsbereich and separated from each other in a front side of the toothed ring and the gear (in particular to the teeth formed by the teeth tooth areas of the toothed ring and the gear) adjacent, in particular immediately adjacent, Rotorkammerwand the pump housing formed or open there. In particular, in connection with such an embodiment, it is advantageous in terms of production if the at least one relief channel is formed in a wall region of the rotor housing wall adjacent to the tooth engagement region, in particular immediately adjacent, and from there proceeding to the space likewise formed in the rotor chamber wall or opening Pressure chamber is guided. In terms of manufacturing technology, the at least one discharge channel is preferably designed as a groove open towards the rotor chamber and thus towards the toothed ring / gearwheel.

The at least one discharge channel is formed according to a specific advantageous embodiment, with a particularly good discharge of the squish flow from the meshing region is possible, such that its tooth-engaging portion side channel end is assigned in the meshing region only the outer tooth of the inner gear.

Furthermore, a concrete embodiment is particularly preferred in which the at least one relief channel is dimensioned with regard to its channel cross-section so that at least 60% of a squish flow in a tooth engagement region can be diverted out of it into the pressure chamber. This ensures that the largest possible amount of squish flow flows out of the tooth engagement region away from the pressure chamber.

In the special design of the at least one discharge channel lie for a current pump design targeted optimization possibilities. As a result, psychoacoustic noise, in particular with regard to the loudness in the frequency groups Bark 5-15 and with regard to roughness, can be minimized. In this case, the at least one discharge channel with regard to its channel cross-section and / or its channel length be designed so that the specific loudness of the pump is lowered during operation in the frequency groups Bark 5-15 such that this is a maximum of 3 sone / Bark and / or thereby in the range of the frequency groups Bark 5-15 a maximum roughness of 1.2 asper / Bark results.

In a further particularly preferred embodiment of the internal gear pump according to the invention, moreover, at least one additional channel can be provided, which forms a flow connection between the tooth adjacent region and the pressure chamber. As a result, the pressure surge of the pumped fluid is advantageously minimized at the transition from the suction chamber to the pressure chamber, so that psychoacoustic parameters are also optimized with this measure, without resulting in losses in efficiency.

Here too, analogously to the relief channel, it may then be provided that the at least one additional channel is formed in a wall region of the rotor chamber wall which adjoins the tooth adjacency region and from there leads to the pressure chamber which is also spaced apart from it in the rotor chamber wall and / or opening is, with further preference may be provided that the at least one additional channel is designed as a groove open towards the rotor chamber. This results in an advantageous functional and easy to manufacture embodiment.

In the special design of the at least one additional channel are also in turn for a current pump design specifically usable optimization options. Thus, the at least one additional channel with respect to its channel cross-section and / or its channel length is preferably designed so that the specific loudness of the pump is lowered during operation in the frequency groups Bark 3-10 such that this is a maximum of 4 sone / Bark and / or thereby a maximum roughness of 2 asper / Bark in the range of the frequency groups Bark 3-10 results.

According to a further preferred and structurally simple pump configuration, it is provided that the suction chamber and the pressure chamber lie on opposite sides of a reference plane defined by the tooth engagement region and the tooth adjoining region (where the tooth engagement region and the tooth adjuster region are advantageously opposite one another) and respectively spaced from these regions in one of the rotor chambers Open the front wall of the pump housing. Alternatively or additionally, this reference plane but also by one or more axes of rotation of the toothed ring or internal gear, of which at least one is rotatable, be placed.

By a suitable design of the discharge channel and / or the additional channel thus the specific loudness and roughness can be defined so that in addition to a significant reduction of the pressure pulsation and reduction of the emitted sound pressure level results in a significant optimization of the psychoacoustic parameters, which does not cause loss of efficiency.

The internal gear pump is, according to a particularly preferred embodiment, a trochoidal pump in which the teeth mesh with each other in a trochoidal manner.

Particularly preferred is an embodiment in which the inner gear has an outer tooth less compared to the inner teeth of the toothed ring. Particularly advantageous results have been achieved in this context with a trochoidal pump in which the toothed ring has seven inner teeth and an inner toothed wheel has six outer teeth.

The toothed ring is, for example, an outer rotor rotatably disposed in the rotor chamber. Alternatively, however, only the internal gear can be formed as a rotationally driven inner rotor. Particularly preferred is an embodiment in which both the toothed ring as an outer rotor and the inner gear are rotationally driven as an inner rotor.

The advantages associated with the claimed vehicle are identical to the advantages mentioned above and are not explicitly repeated here.

The invention will be further explained by way of example only with reference to a drawing.

Show it:

1 a plan view of a trained as Trochoidenpumpe internal gear pump in the axial direction with the housing cover removed, and

2 a section through the Trochoidenpumpe after 1 along the reference plane AA.

In 1 is a plan view of a Trochoidenpumpe 1 (without housing cover) executed internal gear pump and in 2 a sectional view along the reference plane 2 (Line AA) 1 shown.

The trochoid pump 1 has a pump housing 3 with a preferably cylindrical rotor chamber 4 on, which through a chamber lid 5 (please refer 2 ) is closed in the operating state. In 1 is the chamber lid 5 omitted for an insight into the chamber interior.

In the rotor chamber 4 is an outer rotor with a preferably same cylindrical circumference 6 rotatably mounted, as a toothed ring with several, here only exemplary seven, inwardly directed internal teeth 7a to 7g is trained. The cylinder axis of the rotor chamber 4 or the axis of rotation for the outer rotor 6 is with the reference numeral 8th characterized.

In the outer rotor 6 is an inner rotor 11 arranged eccentrically or stored, by means of a drive shaft 9 around a drive axle 10 is rotated. The inner rotor 11 is here preferably with an external tooth less and thus in the example shown here with six external teeth 12a to 12f Mistake. The inner teeth 7a to 7g and the outer teeth 12a to 12f Grasp trochoidal shaped into each other.

The reference plane 2 goes through the middle of a first (top) dead center position 13 , through the two eccentrically offset axes 8th and 10 and by a second, substantially opposite and bottom dead center position 14 , At the first dead center position 13 lies in a meshing area 13a an external tooth 12a in an internal tooth space (here between the internal teeth 7a and 7g ) substantially completely or fully, that is substantially gap-free or a shape and contour adapted. At the second dead center position 14 on the other hand there is an external tooth 12d in a dental adjacency area 14a on the inner tooth 7d on the head or adjacent to there.

When turning counterclockwise (rotation arrow 15 ) increase from the reference plane 2 and the first dead center position 13 in the left-hand rotor chamber area in each case the volumes between the internal teeth and external teeth as pump chambers 16 until reaching the second dead center 14 , This is due to the enlarging pump chambers 16 from a suction room 17 aspirated fluid sucked. The suction room 17 is shown here only by dashed lines and in a rotor chamber wall 4a the rotor chamber 4 , frontally adjacent to the tooth areas of the inner rotor 11 and outer rotor 6 formed (a fluid connection line as an inlet is not shown for reasons of clarity).

In the further course of a revolution of the inner rotor 11 are in the rotor chamber area to the right of the reference plane 2 and starting from the second dead center position 14 the pump chambers 16 in a movement to the first dead center 13 down, which in the suction chamber 17 absorbed fluid from the pump chambers 16 in a pressure room 18 is pressed and derived from this with a (not shown for clarity) pump line. Also the pressure room 18 is shown here schematically dashed and (as well as the suction chamber 17 ) frontally adjacent to the outer rotor 6 and inner rotor 11 in a rotor chamber wall 4a the rotor chamber 4 educated. The suction room 17 and pressure room 18 can, as in 1 shown in or on the same rotor chamber wall 4a be formed or alternatively also on different rotor chamber walls 4a be trained, for example, as in 2 shown, on opposite rotor chamber walls 4a be arranged.

How further from the 1 it can be seen has both the suction chamber 17 as well as the pressure room 18 a defined distance to the meshing area 13a and to the dental adjacency area 14a on, leaving the rotor chamber walls 4a There are essentially immediately adjacent. This may cause it in the meshing area 13a come to the formation of the already mentioned squish flows or in the Zahnangrenzungsbereich 14a come to the generation of pressure surges.

In order to avoid this and thus to reduce noise, in the illustrated embodiment, a Trochoidenpumpe 1 in one to the meshing area 13a essentially immediately adjacent wall region of the rotor chamber wall 4a a groove-like discharge channel 19 and in one to the Zahnangrenzungsbereich 14a essentially immediately adjacent wall region of the rotor chamber wall 4a a groove-like additional channel 20 formed, that is, in other words, in or on a substantially directly to the front side of the outer rotor 6 and inner rotor 11 adjacent area of the rotor chamber wall 4a the rotor chamber 4 formed, and from there in the rotor chamber wall 4a to the spaced also in the rotor chamber wall 4a opening or trained pressure room 18 guided.

Both the discharge channel 19 as well as the additional channel 20 can in this case as the rotor chamber 4 open groove may be formed, but optionally also as inside the rotor chamber wall 4a be formed extending channel.

The discharge channel 19 runs in the illustrated embodiment, starting from the reference plane 2 and thus starting middle of Tooth engagement area 13a as a flow channel in the pressure chamber 18 , As a result, squish flows in the meshing area 13a avoided and into the pressure room 18 derived and thus in particular advantageously reduces psychoacoustic noise.

The additional channel 20 extends from the center of the Zahnangrenzungsbereiches 14a as a flow channel also in the pressure chamber 18 , This pulse-like pressure surges are at this point at the transition from the suction chamber 17 to the pressure room 18 reduced, whereby a further noise reduction is achieved.

LIST OF REFERENCE NUMBERS

1

trochoid

2

reference plane

3

casing

4

rotor chamber

4a

Rotor chamber wall

5

chamber cover

6

outer rotor

7a-7g

internal teeth

8th

Outer rotor axis

9

drive shaft

10

drive axle

11

inner rotor

12a-12f

external teeth

13

first dead center position

13a

Meshing area

14

second dead center position

14a

Zahnangrenzungsbereich

15

rotation arrow

16

pump chamber

17

suction

18

pressure chamber

19

relief channel

20

additional channel

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 60302110 T2 [0006]

Claims (15)

Internal gear pump, in particular trochoid pump, for a vehicle, with a pump housing ( 3 ) with a rotor chamber ( 4 ), in which, an internal toothing with internal teeth ( 7a - 7g ) having toothed ring ( 6 ) with an eccentric to the toothed ring ( 6 ) and external teeth with external teeth ( 12a - 12f ) having gear ( 11 ) is engageable in such a way that at a tooth engagement area ( 13a ) at least one of the external teeth ( 12a ) in one between two internal teeth ( 7a ; 7g ) lying inner tooth space, wherein the pump chambers ( 16 ) forming volumes between the internal teeth ( 7a - 7g ) and the external teeth ( 12a - 12f ) in one, a suction space ( 17 ) associated rotor chamber area, starting from the meshing area ( 13a ) to a tooth adjoinment area ( 14a ), in which at least one external tooth ( 12d ) on the head side on an internal tooth ( 7d ) adjoins or rests, grows larger and in one, a pressure chamber ( 18 ) associated rotor chamber area, starting from the tooth adjacency area ( 14a ) up to the meshing area ( 13a ) become smaller again, characterized in that at least one discharge channel ( 19 ), which provides a flow connection between the tooth engagement region (FIG. 13a ) and the pressure chamber ( 18 ) trains. Internal gear pump according to claim 1, characterized in that the suction chamber ( 17 ) and the pressure chamber ( 18 ) spaced from the meshing area (FIG. 13a ) and / or the tooth adjoinment area ( 14a ) and separated from each other in a front side of the toothed ring ( 6 ) and the gear ( 11 ) adjacent, in particular immediately adjacent, Rotorkammerwand ( 4a ) of the rotor chamber ( 4 ) are formed and / or open there. Internal gear pump according to claim 2, characterized in that the at least one discharge channel ( 19 ) in one to the meshing area ( 13a ) adjacent, in particular immediately adjacent, wall region of the rotor chamber wall ( 4a ) and from there to the spaced apart also in the rotor chamber wall ( 4a ) trained and / or opening pressure space ( 18 ) is guided. Internal gear pump according to claim 2 or 3, characterized in that the at least one discharge channel ( 19 ) than to the rotor chamber ( 4 ) is formed open groove. Internal gear pump according to claim 3 or 4, characterized in that the at least one discharge channel ( 19 ) is designed in such a way that its tooth engagement region-side channel end in the tooth engagement region (FIG. 13a ) only the external tooth ( 12a ) of the internal gear ( 11 ) assigned. Internal gear pump according to one of the preceding claims, characterized in that the at least one discharge channel ( 19 ) is dimensioned with respect to its channel cross-section so that at least 60% of a squish flow from the tooth engagement region ( 13a ) into the pressure chamber ( 18 ) are derivable. Internal gear pump according to one of the preceding claims, characterized in that the at least one discharge channel ( 19 ) is designed with respect to its channel cross-section and / or its channel length so that the specific loudness of the pump is lowered during operation in the frequency groups Bark 5-15 such that this is a maximum of 3 sone / Bark and / or thereby in the range of the frequency groups Bark 5-15 gives a maximum roughness of 1.2 asper / bark. Internal gear pump according to one of the preceding claims, characterized in that at least one additional channel ( 20 ), which provides a flow connection between the tooth area ( 14a ) and the pressure chamber ( 18 ) trains. Internal gear pump according to claim 8, characterized in that the at least one additional channel ( 20 ) in one at the tooth adjacency area ( 14a ) adjacent, in particular immediately adjacent, wall region of the rotor chamber wall ( 4a ) and from there to the spaced apart also in the rotor chamber wall ( 4a ) trained and / or opening pressure space ( 18 ) is guided. Internal gear pump according to claim 9, characterized in that the at least one additional channel ( 20 ) than to the rotor chamber ( 4 ) is formed open groove. Internal gear pump according to one of claims 8 to 10, characterized in that the at least one additional channel ( 20 ) is designed with respect to its channel cross-section and / or its channel length so that the specific loudness of the pump is lowered during operation in the frequency groups Bark 3-10 such that this is a maximum of 4 sone / Bark and / or thereby a maximum roughness of 2 asper / Bark in the area of the frequency groups Bark 3-10. Internal gear pump according to one of the preceding claims, characterized in that the suction chamber ( 17 ) and the pressure chamber ( 18 ) on opposite sides of a through the meshing area ( 13a ) and the area around the teeth ( 14a ) reference plane ( 2 ) and in each case at a distance from these areas ( 13a . 14a ) in one of the rotor chambers ( 4 ) associated rotor chamber wall ( 4a ) of the pump housing ( 3 ). Internal gear pump according to one of the preceding claims, characterized in that the toothed ring ( 6 ) rotatable in the rotor chamber ( 4 ) arranged outer rotor and / or the inner gear ( 11 ) is an inner rotor rotationally mounted in the outer rotor. Internal gear pump according to one of the preceding claims, characterized in that the gear pump ( 1 ) is a Trochoidenpumpe in which the teeth mesh trochoidal shaped and / or the gear ( 11 ) an external tooth ( 12 ) less compared to the internal teeth ( 7 ) of the toothed ring ( 6 ) having. Vehicle, in particular commercial vehicle, with a gear pump ( 1 ) according to any one of the preceding claims.

Images