WO2018172059A1

WO2018172059A1 - Internal gear machine

Info

Publication number: WO2018172059A1
Application number: PCT/EP2018/055418
Authority: WO
Inventors: Steffen SCHÖNTHALER
Original assignee: Voith Patent Gmbh
Priority date: 2017-03-22
Filing date: 2018-03-06
Publication date: 2018-09-27
Also published as: DE102017106140A1

Abstract

The invention relates to an internal gear machine (1) for reversing operation, comprising an externally toothed pinion (3) and an internally toothed ring gear (4). The ring gear (4) meshes with the pinion (3). A sickle-shaped cavity (7) is formed by the pinion (3) and the ring gear (4). A filling piece (14) is arranged in the cavity (7) formed by the ring gear (4) and the pinion (3). The filling piece (14) has an inner side (15) and an outer side (16) and the inner side (15) is connected to the outer side (16) by means of a first yoke (17) and a second yoke (18). An internal volume (20) is enclosed by the filling piece (14).

Description

Internal gear pump

The invention relates to an internal gear machine, in particular a reversible gear machine with a filler. Such gear machines can be operated as a pump or generator.

From WO 01/02730 an internal gear machine is known. Such machines can be used as a gear pump. In the internal gear pump known from this document, a longitudinally divided filler is provided. The filler is symmetrical with respect to a radially extending plane of symmetry. As a result, operation of the internal gear pump is reversible, i. The pump can deliver in both directions. The filler is multi-part, divided in the circumferential direction, constructed. In the description it is mentioned that the filler could also be constructed in one piece. However, a one-piece filler is not disclosed.

From DE 10 2012 207 259 A1 a gear pump with a filling piece is known which has two legs. The two legs are connected by a bridge and include an internal volume. By forming an inner pressure, the legs are pressed apart in the radial direction. The pressure in the inner volume is established by a circumferentially formed opening to the pressure or suction area by pressure equalization. The filler is not symmetrical. The filler used in gear pumps are also referred to as sickle.

So far, multi-part compensation elements are used for volumetric efficiency increase of internal gear pumps. These components function independently of each other and are usually used in asymmetric design. When used in multi-range pumps, the filler pieces are often symmetrical, but usually constructed in several parts. The disadvantage of this construction is the susceptibility to negative pressures, causing a collapse can result or system vibrations, in particular a tendency to vibration. Frequently, such multi-section pumps exhibit inertia in the pressure buildup and depressurization due to the movable parts and / or the freedom of movement between the spline components. Another disadvantage is that tilting is possible through tolerances and a movement play. Compared to a one-piece patch result from a multi-part higher manufacturing costs.

The object of the invention is to provide a filler for an internal gear machine and an internal gear machine, with a more stable operation can be achieved.

The object is achieved by an embodiment according to claim 1 and 12. Further advantageous features of the embodiment according to the invention can be found in the subclaims.

In the embodiment of the invention, the filler comprises an inner side and an outer side. The inner side is connected to the outside via a first yoke and a second yoke, wherein an internal volume is enclosed by the filler. Preferably, the filler is inflatable. By this is meant that the volume of the enclosed inner volume is adjustable by a pressure prevailing in the inner volume or the pressure ratio of inner volume and the pressure acting on the outside of the filler.

In a preferred embodiment, in each case the connections between the first and second yoke and the inside are made hydraulically tight. Furthermore, the connections between the first and second yoke and the outside are made hydraulically tight. By the first and the second yoke, the internal volume is limited and completed. To provide an internal volume, the inside is spaced from the outside by a distance.

For a reversible operation, a symmetrically constructed to a symmetry plane filler is advantageous, so that the influenceable by the filler power curves of the internal gear machine are the same in both operating directions. In a preferred embodiment, the filler is formed symmetrically symmetrical to a the inside and the outside intersecting plane of symmetry. The filler is provided for installation within a cavity formed by an internally toothed ring gear and an externally toothed pinion. In this case, the inside is provided for a radially inwardly from the outside arrangement with respect to the radial direction of the pinion. In particular, the inside is designed for a partial abutment on the external toothing of the pinion. The outside is disposed radially outward from the inside with respect to the radial direction of the pinion. The outside is designed for a concern with the internal toothing of the ring gear.

In a preferred embodiment, the filler is provided with at least one supply opening for pressure equalization, preferably with the pressure side. This makes it possible that with increasing pressure on the pressure side, the pressure in the inner volume automatically adapts to this pressure prevailing on the pressure side. By the number and size of the supply openings, the dynamics of the pressure change of the internal volume can be predetermined. With increasing pressure in the inner volume, the sealing effect can be increased compared to the suction side and pressure side. This reduces the leakage losses.

In a preferred embodiment it is provided that at least one supply opening is formed in the inside and / or the outside in the filler. In a particularly preferred embodiment, the formed at least one supply opening in the inside. This is easier to manufacture.

In a preferred embodiment, supply opening is provided on the outside. As a result, the time available for a pressure equalization when arranged on longer.

In a preferred embodiment it is provided that the supply opening is designed to intersect the plane of symmetry in the filler. As a result, a pressure equalization of the internal volume can be ensured independently of the operating direction or the operating mode of the internal gear machine during later operation.

Preferably, depressions of the control geometry are aligned in the circumferential direction.

In a preferred embodiment it is provided that a control geometry assigned to the supply opening is provided, wherein the control geometry in at least one of the walls comprises at least one formed depression. The control geometry interacts with the supply opening. Preferably, the supply opening is disposed within one of the recesses of the control geometry.

In a preferred embodiment it is provided that the inside and the outside are curved to provide a spring elasticity. In particular, the inner side and / or the outer side may be configured in the shape of a leaf spring.

In a preferred embodiment, the filler is integrally formed. As a result, in comparison with a multipart filling piece, in particular the assembly costs and also the production costs can be reduced. In a preferred embodiment, a bulge of the inner volume is formed in a transition region between a yoke and the inside or outside. When installed, the transition area forms an entry phase and exit phase depending on the operating mode. By forming the bulge, a geometry for providing an optimized pressure surface effect is achieved. Due to the internal pressure, the filler has the tendency to expand in all directions. This could result in unwanted deformations. By the bulges a preferred deformation can be achieved. An equal fitting geometry of the teeth can be achieved.

In a preferred embodiment, at least one yoke is preferably the first and the second yoke formed with a receiving geometry for receiving a storage. As a result, a simple assembly and a simple position fixing can be achieved. In addition, it is possible to provide a predetermined bias of the filler over the receiving geometry.

The object underlying the invention is achieved by an internal gear machine with a filling piece according to the invention.

The internal gear machine for the reversing operation has an externally toothed pinion. The externally toothed pinion meshes with an internally toothed ring gear. By pinion and ring gear a crescent-shaped cavity is formed. In the crescent-shaped cavity, a filler is arranged. Through the centers of pinion and ring gear runs a plane of symmetry. By the filler according to the invention with a first and a second yoke and an inner volume, a more stable operation of the internal gear machine can be achieved.

In a preferred embodiment of an internal gear machine it is provided that at least one axial disc is provided, wherein the axial disc is provided with a pressure supply bore penetrating the axial disc. This pressure supply hole opens in the inner volume of the filler. This can ensure that the axial disc is acted upon on the side remote from the pinion and ring gear with fluid from the internal volume. As a result, the axial disc is pressed in the direction of pinion and ring gear. As a result, leakage losses can be reduced.

In a preferred embodiment of an internal gear machine it is provided that the filler is mounted under tension between two fixing pins arranged in the cavity. As a result, on the one hand by the position of the fixing pins, the filler can be mounted under a predetermined bias and on the other hand, the assembly is particularly simple.

By way of embodiments, further advantageous embodiments of the invention will be explained with reference to the drawings. The features mentioned can not only be implemented advantageously in the illustrated combination, but also individually combined with each other. The figures show in detail:

Fig.1 internal gear machine

Fig.2 filler in 3D view

3 shows another illustration of the filling piece from FIG. 2

Fig.4 Axial disc with pressure supply hole

Fig.5 variant of a filling piece

6 further variant of a filling piece

Fig. 7 further embodiment of a filler

Fig. 8 section through an internal gear machine with an axial disc

The figures are described in more detail below.

FIG. 1 shows a section through an internal gear machine 1. The Innenzahnradmaschinel can be operated as a pump or generator. The illustrated internal gear machine 1 is designed for reversible operation. The gear machine has a housing 2. In the housing 2, a pinion 3 is rotatable about a center 5 and a ring gear 4 rotatable about a Center 6 stored. The pinion 3 meshes with the ring gear 4, wherein the axes of rotation of pinion 3 and ring gear 4 are spaced from each other and arranged parallel to each other. By the pinion 3 and the ring gear 4 a sickle-shaped extending in the axial direction cavity 7 is formed. In the cavity 7, a filler 14 between two provided as a bearing 22 fixing pins 23 is arranged. The filler 14 has an inner side 15 and an outer side 16. The inner side 15 is connected to the outer side 16 on one side via a first yoke 17 and on the opposite side via a second yoke 18. The outer side 16 is arranged to the inner side 15 in the radial direction 36 with a distance. The first yoke 17 is arranged in the circumferential direction 37 to the second yoke 18 at a distance. The teeth of the pinion 3 come into contact with the inner side 15, so that the cavities formed between the teeth are sealed in the radial direction 36 by the inner side 15 of the filler 14. The outside 16 of the filler 14 is in touching contact with the teeth of the ring gear 4, so that the cavities formed between the teeth of the ring gear 4 are sealed by the outside 16. By means of these sealed by the filler 14 cavities hydraulic medium, preferably a liquid such as oil, transported from the suction side 13 to the pressure side 12. The filler 14 is arranged symmetrically to a plane of symmetry 8. The plane of symmetry 8 extends through the middle point 15 of the axis of rotation of the pinion 3 and through the center 6 of the axis of rotation of the ring gear 4. The plane of symmetry 8 coincides with the plane of symmetry 8a of the filler 14. Through the inner side 15, the outer side 16 and the first and the second yoke 17, 18, an inner volume 19 is enclosed by the filler 14.

An interpretation of an axial disc 25, as shown in detail in Fig. 4, can be seen. From the axial disc 25 is a pressure supply hole 24, which opens into the interior volume 19 can be seen. In the Axialscheibe a Axialdruckfeld with control geometry 26 is formed. A first and a second fluid connection 9, 10 can be seen. With reference to Figures 2 and 3, the filler 14 will be described in more detail. The filler 14 is provided with a supply port 20 through which a hydraulic connection is provided from the interior volume 19 to the outside. The supply opening 20 is formed in the radial direction. This supply opening 20 is formed in the illustrated embodiment in the inner side 15. In addition, a control geometry 21 is formed, which cooperates with the supply opening 20. In the embodiment shown, the control geometry is also formed in the inner side 15. The extent in the circumferential direction of the control geometry 21 is designed so that it is ensured that a direct connection with the suction side 13 and the pressure side 12 does not occur during operation of the internal gear 1 and a connection of the control geometry 21 only with the between inside 15 and the teeth the pinion formed cavities is possible and about a pressure compensation takes place.

If the supply opening 20 and the control geometry 21 are formed in the outer side 16, then the extension of the control geometry in the circumferential direction is selected so that a connection of the control geometry 21 is possible only with the cavities formed by the teeth of the ring gear 4 and the outer side 16 and in turn a direct connection with the suction side 13 or pressure side 12 of the internal gear machine 1 in normal operation is not possible.

The control geometry 21 is formed symmetrically to the plane of symmetry 8a of the filler 14 and the supply opening 20, the symmetry plane 8a cutting, arranged.

The filler 14 is symmetrical to allow 4-Qadranten operation. The filler 14 is integrally formed in the illustrated embodiment. The inner volume 19 is enclosed in the radial and in the circumferential direction and forms a pressure chamber. Due to this closed configuration, the inner volume 19 with pressure be charged. By pressurization, puffing can be achieved. It is an elastic deformation of the filler 14th

The yoke 17, 18 is formed with a transition region 30, which is referred to as the entry and exit phase. The inside 15 and the outside 16 are formed with a resilient geometry 34, 35. In the embodiment shown, the inner side 15 and the outer side 16 have the shape of a leaf spring. Furthermore, the filler 14 was formed with bulges 32. The bulges 32 have an Anpressgeometrie 33, wherein the angles of the inner surfaces of the bulge 32 in the transition region 30 are designed so that the forces generated by an internal pressure and in correlation with the fixing pins 23 contribute to a radial sealing effect. Due to the symmetrical design this is possible in the complete 4-quadrant range of a motor and generator operation. A pressure equalization of the inner volume 19 of the filler 14 with the pressure side for an increased sealing effect is realized by means of a radial opening in the form of a supply opening 20. This can be located on the side of the pinion 3 or the ring gear 4 and interacts with a control geometry 21, here in the form of control grooves. The control geometry 21 can be varied by its design and geometry.

About the inflatable filler 14, the axial disc 25 is controlled. The axial disc 25 is supplied by an axial pressure supply bore 24 in the region of the inner volume 19 of the filler 14. As a result of this supply, the axial disk is subjected to pressure on the side facing away from the pinion 3 and ring gear 4 and thus printed as an axial conclusion in the direction of pinion 3 and ring gear 4.

The filler 14 is designed by the structure so that it by the radially applied supply opening 20 with control geometry 21 on the Hohlrad- and Pinion gear is supplied with oil pressure and by the internal pressure caused by the radial forces can inflate. This assumes that the filler 14 has a closed contour / cavity at least towards the suction side 13 and pressure side 12. The swelling creates a radial sealing effect that automatically increases with increasing operating pressure. The axial sealing takes place via the axial disc 25 and the opposite bearing cap. But it could also be provided on both sides Axialscheiben 25.

The geometric structure is designed so that the filler 14 is biased in the unpressurized state by utilizing the inherent resilience of the material. The inner side 15 and the outer side 16 are similar to the cross section of a leaf spring, installed between the ring gear 4 and the pinion 3. Due to the distance of the fixing pins 23 used as a bearing 22, a predetermined bias can be specified in the assembled state. In addition, it is possible to increase the contact pressure by a further spring element.

FIG. 4 shows an axial disk 25. Axial pressure fields with control geometry 26 are formed in the axial disk. Dashed lines indicate kidney-shaped pockets 46 are formed on the back. The kidney-shaped pockets 46 are axially defined by kidney-shaped axial piston 48, shown in phantom. The kidney-shaped axial piston 48 are received in the kidney-shaped pockets 46 of the axial disc 25. Between axial piston 48 and the kidney-shaped pocket 46 forming recess is still a seal 49, shown in phantom, provided. By the seal 49 ensures that the volume of the kidney-shaped pockets 46 is completed. If the kidney-shaped pockets 46 are then pressurized, the axial piston 48 is thereby pressed axially out of the axial disc 25 and thus out of the kidney-shaped pocket 46. As a result, a support of the axial disc 25 is achieved against the housing 2 or the bearing cap. To supply the kidney-shaped pockets 46, a supply bore 42, shown in dashed lines, formed in the axial disc 25. The supply bore 42 is connected to the pressure supply bore 24. On the other side, the supply bore 42 is connected to a transverse bore 41, shown in phantom. The transverse bore 41 is in turn connected via a respective inflow 44 with the kidney-shaped pockets. About these compounds 24, 42, 41, 44, the kidney-shaped pockets 46 are acted upon via the inner volume 19 of the filler 14 with hydraulic medium. In addition, a speed controller 27 is provided. In the axial disc 25 Fixierbohrungen 28 are formed so that the axial disc 25 can be mounted axially displaceable on the fixing pins 23.

FIGS. 5 and 6 show alternative embodiments of filler pieces 14. The filling piece 14 shown in FIG. 5 has on both sides a curvature formed in the direction of the inner volume for receiving the fixing pins 23. It is a supply opening 20 in the axial center and also formed in the middle with respect to the circumferential direction 37 of the inner side 15 of the filler 14. The supply opening is arranged in the radial direction of the filler. Instead of only one supply opening could be arranged offset in the axial direction arranged supply openings. By forming the size of the dynamics of a flatulence of the filler can be influenced. Furthermore, the supply opening 20 is assigned a control geometry 21. FIG. 5 shows a control geometry which is formed by depressions. These depressions are arranged at a distance in the axial direction 38 and extend in the circumferential direction 37. The dynamics of the swelling behavior or the dynamics of a pressure compensation of the inner volume 19 are also determined by the control geometry 21. The depressions are tapered in the circumferential direction 37. About the control geometry 21 a plurality of cavities formed by the inner side 15 and the teeth of the pinion are interconnected. In the embodiment shown in Figure 6, the control geometry 21 recesses, which are configured in the circumferential direction 37 angular. Again, the control geometry comprises a plurality of depressions, which are arranged parallel to each other and spaced apart in the axial direction 38. The control geometry 21 is always formed on the side facing away from the inner volume 19 side of the inner side 15 or the outer side 16.

In Figure 7, an alternative contour of a filler 14 is shown in section. In this embodiment, the first and the second yoke are formed with an outer curvature. Such a filler 14 may be supported by a bearing 22 provided in the inner volume. Also, such a filler 14 can be mounted by a arranged outside the filler and adapted to the outer contour of the filler 14 in the region of the first 17 and second yoke 18 storage 22 and also stored biased.

In Figure 8, the axial disc is shown in section. It can be seen that the connecting bore 42 is formed within the axial disc 25. For this reason, the connection hole 42 is provided with a shutter 43. Specifically, the connecting hole 42 is caulked by a ball. Opening the connection hole is not provided. Likewise, the transverse bore is caulked by a closure 43.

LIST OF REFERENCE NUMBERS

1 internal gear machine

2 housings

3 pinions

4 ring gear

5 center pinion

6 center ring gear

7 cavity

8 symmetry plane

9 First fluid connection

10 Second fluid connection

12 print side

13 suction side

14 filler

15 inside

16 outside

17 First yoke

18 Second yoke

19 internal volume

20 supply opening

21 control geometry

22 Storage

23 fixing pin

24 pressure supply hole

25 axial disk

26 Axial pressure field with control geometry

27 speed control

28 fixing hole

30 phase-out yoke

32 bulge Anpressgeometrie

Spring geometry inside

Federgeomethe outside

Radial direction of the filler

Periphery of the filler

Axial direction of the filler

cross hole

connecting bore

shutter

Inflow to 46

kidney shaped bag

axial piston

Seal axial piston

Claims

claims

1 . Filler (14) for an internal gear machine (1), wherein the internal gear machine (1) is designed for reversible operation,

characterized,

in that the filler piece (14) comprises an inner side (15) and an outer side (16) and the inner side (15) is connected to the outer side (16) via a first yoke (17) and via a second yoke (18) the filler (14) an internal volume (20) is included.

2. Filler according to claim 1,

characterized,

the filler piece (14) is formed symmetrically to a plane of symmetry (8) which intersects the inner side (15) and the outer side (16).

3. Filler piece according to one of the preceding claims,

characterized,

in that the filling piece (14) is provided with a supply opening (20) for pressure equalization, preferably with the pressure side (12).

4. Filler according to claim 3,

characterized,

the supply opening (20) is formed in the inside (15) and / or the outside (16) in the filling piece (14).

5. Filler according to one of the preceding claims 3 or 4,

characterized,

the supply opening (20) is designed to cut the symmetry plane (8) in the filling piece (14).

6. Filler piece according to one of the preceding claims 3 to 5,

characterized, the supply opening (20) is designed to penetrate the inside (15) of the filler (14).

7. Filler according to one of claims 3 to 6,

characterized,

in that a control geometry (21) assigned to the supply opening (20) is formed, wherein the control geometry (21) interacts with the supply opening (20).

8. Filler piece according to one of the preceding claims,

characterized,

in that the inner side (15) and the outer side (16) are curved to provide spring elasticity.

9. Filler piece according to one of the preceding claims,

characterized,

that the filler (14) is integrally formed.

10. filler according to one of the preceding claims,

characterized,

a bulge (32) of the inner volume (19) is formed in a transition region between a yoke (17, 18) and the inner side (15) or outer side (16).

1 1. Filler according to one of the preceding claims,

characterized,

in that at least one yoke (17, 18), preferably the first (17) and the second yoke (18), are formed with a receiving geometry (33) for receiving a bearing (22).

12. internal gear machine (1) for the reversing operation with an externally toothed pinion (3), with an internally toothed ring gear (4), wherein the ring gear (4) meshes with the pinion (3) and wherein by pinion (3) and ring gear (4) a sickle-shaped cavity (7) is formed and with a filler (14), wherein the filler (14) in the by the ring gear (4) and the pinion (3) formed cavity (7) is arranged and wherein through the center points (5 , 6) of pinion (3) and ring gear (4) has a plane of symmetry,

characterized,

in that the internal gear machine (1) has a filling piece (14) according to one of the preceding claims.

13. internal gear machine according to claim 12, with at least one axial disc (25)

characterized,

the axial disc (25) is provided with a pressure supply bore (24) penetrating the axial disc (25) and the pressure supply bore (24) discharges into the internal volume (19) of the filler (14).

14. Internal gear machines according to claim 12 or 13,

characterized,

the filler (14) is mounted under tension between bearings (in particular two fixing pins (23) arranged in the cavity (7).

15. Internal gear machine according to one of the preceding claims 12 to 14,

characterized,

that the supply opening (20) of the filler in normal operation is not directly connected to the suction side (13) or pressure side (12).