EP2406497B1 - Hydraulic toothed wheel machine - Google Patents

Description

The invention relates to a hydraulic gear machine according to the preamble of patent claim 1.

In the EP 1 291 526 A2 is a gear machine shown with a housing in which two intermeshing and mounted in bearing bushes or bearing bodies gears are arranged, wherein the housing is closed at each end face with a first and second housing cover. The helical gears are slidably mounted axially with two axial surfaces between the bearing bodies and radially in each case via a bearing shaft received in the bearing bodies. During operation of the gear machine, hydraulic and mechanical forces act on the gears in the same gear longitudinal axis in each case. So that the lying in the effective direction of the forces first bearing body is not pressed over the axial surfaces of the gears between the gears and the first housing cover and between the gears and the second bearing body only a small sliding gap occurs, a counter force is applied to the gears and the first bearing body. This is greater than the hydraulic and mechanical forces, so that the first bearing body against the gears, the gears against the second bearing body and the second bearing body are pressed against the second housing cover. The force resulting on the bearing body and the gears thus all act in the direction of the second housing cover.

The IT 1 124 357 is considered to be the closest prior art and discloses the features of the preamble of claim 1.

The counterforce on the gears is applied via attacking on the bearing shafts piston. The pistons are slidably received approximately coaxially to the toothed wheel longitudinal axis in a between the first housing cover and the housing arranged intermediate cover and abut with a first piston end face on a pointing in the direction of the first housing cover shaft end face of the bearing shafts and are acted upon via a second piston end face in each case with pressure. The counterforce is applied to the first bearing body via a pressure field formed between the bearing body and the intermediate cover.

A disadvantage of this solution is that the entire package of bearing bodies and gears is pressed onto the second housing cover of the gear machine, whereby the second housing cover and the housing are loaded very high and uneven. Furthermore, quite high wear occurs due to the compression of the gears and the bearing bodies between the axial surfaces of the gears and the bearing bodies.

The object of the present invention is to provide a hydraulic gear machine with a low force application of machine elements, in particular housing covers and housing, and with minimal wear.

This object is achieved by a hydraulic gear machine according to the features of patent claim 1.

According to the invention, a gear machine has a housing for receiving two intermeshing and in particular helical gears, which are mounted so as to slide axially with axial surfaces between bearing bodies received in the housing and radially in each case in a bearing shaft received in the bearing bodies. During operation of the gear machine, an axial force component of a force resulting from hydraulic and mechanical forces acts in a same axial direction on one gear each. The gears and / or bearing shafts are then counteracted against the respective Axialkraftkomponente with a counter force which is equal to or less than / as the amount of the respective Axialkraftkomponente.

This solution has the advantage that the gears of the gear machine are each pressed with a reduced by the opposing force Axialkraftkomponente lying in the direction of the Axialkraftkomponente bearing body, which reduces sliding friction between the gears and the bearing body and the other not lying in the effective direction of the Axialkraftkomponente bearing body unloaded is. The reduced by the opposing forces Axialkraftkomponenten can then be provided as Axialspaltkompensation a sliding gap between lying in the effective direction of the force resulting bearing body and the gears. An axial gap compensation of a sliding gap between the not lying in the effective direction of the Axialkraftkomponente Bearing body and the gears can be used independently of the Axialkraftkomponenten. Furthermore, due to the counterforce, a load due to the axial force component on the housing cover and the housing can be reduced.

Preferably, the gears of the gear machine are helically toothed.

Advantageously, the first bearing body lying in the direction of the acting Axialkraftkomponente is pressed mechanically via the gears and / or hydraulically via a pressure force on a housing cover of the housing.

For easy installation of the second bearing body on the gears of the bearing body is applied to a remote from the gears end face with a hydraulic pressure.

Preferably, the reaction force acting on the gears and / or bearing shafts is a hydraulic pressure force and / or a mechanical force.

The counterforce advantageously acts on at least one toothed wheel by means of a pressure field between at least one toothed wheel and the first bearing body. To delineate the pressure field, a pressure pocket can simply be introduced into the axial surface of the at least one gear wheel facing the first bearing body.

The axial surface of a gear consists of tooth surfaces and an annular surface, wherein the pressure pockets is preferably one about a gear longitudinal axis of the corresponding gear approximately concentrically encircling, introduced into the annular surface annular groove. To increase the pressure field and thus the attack surface of the hydraulic pressure, the annular groove can be extended by introduced into the tooth surfaces of the gear tooth pocket sections.

In a further embodiment of the invention is in the first bearing body assigning the axial surface of the driving gear, the annular groove and the first bearing body assigning axial surface of the driving gear, the annular groove together with the Zahntaschenabschnitte introduced because the Axialkraftkomponente is larger in the driving gear than the driven.

Suitably, the pockets with a high pressure of the gear machine in pressure medium connection.

In the gear wheels facing away from the end face of the second bearing body, a pressure field can be introduced and thereby be effected that the second bearing body is lightly pressed against the gears.

Advantageously, in the gear wheels facing away from the end face of the second bearing body, a first pressure groove completely concentrically encircling a first bearing eye and a second pressure groove a pitch circle surrounding a second bearing eye introduced. The pressure grooves are then connected via a pressure medium connection with the high pressure of the gear machine in pressure medium connection.

In a preferred embodiment of the gear machine is in each case to a bearing shaft, a piston in the housing cover of the housing, mounted axially displaceable approximately coaxially with the gear longitudinal axis for applying force to the bearing shafts. The respective piston is arranged with a first piston end face to a pointing in the direction of the axial force component shaft end face of the bearing shaft in approximately fitting and acted upon by a second piston end face with pressure. With the piston, the mechanical counterforce on the bearing shafts can be easily applied.

The second piston end faces are connected for pressurization with the high pressure of the gear machine. The pressure acting on the bearing shafts compressive force can be determined via the piston face diameter.

Other advantageous developments of the invention are the subject of further subclaims.

• Figur 1 in einem Längsschnitt eine vereinfachte Darstellung einer Zahnradmaschine gemäß einem Ausführungsbeispiel;
• Figur 2 in einer Seitenansicht eine vereinfachte Darstellung eines Pakets aus Lagerkörpern und Zahnrädern der Zahnradmaschine aus Figur 1;
• Figur 3 eine Draufsicht auf die Zahnräder eines zweiten Ausführungsbeispiels und
• Figur 4 eine Draufsicht auf einen Lagerkörper eines dritten Ausführungsbeispiels von den Zahnrädern aus.

In the following preferred embodiments of an invention will be explained in more detail with reference to schematic drawings. Show it:

• FIG. 1 in a longitudinal section a simplified representation of a gear machine according to an embodiment;
• FIG. 2 in a side view of a simplified representation of a package of bearing bodies and gears of the gear machine FIG. 1 ;
• FIG. 3 a plan view of the gears of a second embodiment and
• FIG. 4 a plan view of a bearing body of a third embodiment of the gears.

Description of the embodiment

In FIG. 1 is a longitudinal section of a trained as a gear machine 1 hydraulic working machine according to one embodiment shown. This has a machine housing 2, which is closed by means of two housing cover 4 and 6. The Indian FIG. 1 right housing cover 6 of the gear machine 1 is penetrated by a first bearing shaft 8, on which a first gear 10 is disposed within the machine housing 2. The first gear 10 is connected to a second gear 12 via a helical gear 14 into engagement, wherein the gear 12 is rotatably mounted on a second bearing shaft 16. The first and second bearing shaft 8 and 16 are each guided in two plain bearings 18, 20 and 22, 24. The in the FIG. 1 Right sliding bearing 20, 24 are in a bearing body 26 and in the FIG. 1 left slide bearing 18, 22 received in a bearing body 28. The gears 10 and 12 are mounted in the axial direction in each case via a first axial surface 30 and 32 on the second bearing body 26 (right) and in each case via a second axial surface 34 and 36 respectively on the first bearing body 28 (left) slidably. Sliding surfaces between the gears 10, 12 and the bearing bodies 26, 28 may be provided to reduce the friction with a sliding coating, such as MoS ₂ , graphite or PTFE. The bearing bodies 26 and 28 each have an end face 38 or 40 towards the housing covers 6 and 4, respectively.

The housing cover 4, 6 are aligned by centering bolts 42 on the machine housing 2. Between the housing covers 4 and 6 and the machine housing 2, a housing seal 44 is arranged. Furthermore, an axial seal 46 is respectively introduced into the end faces 38 and 40 of the bearing bodies 26 and 28 for the separation of a high and a low pressure region of the gear machine 1. A shaft seal 48 seals the passage of the first bearing shaft 8 through in the FIG. 1 right housing cover 6 from.

In the operation of the gear machine 1, hydraulic and mechanical forces occur, which is schematically illustrated in the following FIG. 2 is explained in more detail.

FIG. 2 shows a simplified side view of a package of gears 10 and 12 and bearing bodies 26 and 28 for explaining the in the gear machine 1 from FIG. 1 operating hydraulic and mechanical forces. A force component of a hydraulic force acts in both gears 10, 12 in the same axial direction in the FIG. 2 to the left. In addition, acting on a driving gear that in the FIG. 2 the upper gear 10 is a mechanical force component of a mechanical force in the direction of action of the hydraulic force component and a driven gear, which in the FIG. 2 the lower gear 12 is a mechanical force component counter to the effective direction of the hydraulic force component. The hydraulic and mechanical force components result in both gears 10, 12 each having a resultant Axialkraftkomponente 47, 49 in the same direction (in FIG. 2 to the left), but with a different amount.

The acted upon by axial force components 47, 49 gears 10 and 12 are respectively based on the axial surfaces 34 and 36 at the in the FIG. 2 left bearing body 28 from. The right bearing body 26 is not loaded by the force acting on the gears 10, 12 Axialkraftkomponenten. To reduce the wear between the gears 10, 12 and the in FIG. 2 left bearing body 28, the gears are subjected to a counter force, resulting in the FIG. 2 marked with dashed arrows.

In the FIG. 1 are in the housing cover 4, two cylindrical pistons 70, 72 guided axially displaceable. These have a different diameter, with the in the FIG. 1 Upper piston has the larger diameter. The first piston 70 is approximately coaxial with in the FIG. 1 upper bearing shaft 8 and the second piston 72 is arranged approximately coaxially with the lower bearing shaft 16. With piston end faces 74 and 76, the respective pistons 70 and 72 respectively extend in the direction of the axial force component 49 FIG. 2 pointing shaft end faces 78 and 80 of the bearing shafts 8 and 16 at. The pistons 70 and 72 are each acted upon via a further piston end face 82 and 84 with a hydraulic pressure and transmit this axially as a counter force on the bearing shafts 8 and 16. For pressurizing the piston end faces 82, 84, a pressure chamber 86 is provided, which of the housing cover 4 and another housing cover, not shown, is limited. The pressure field is connected to the high pressure of the gear machine 1 in fluid communication.

The mechanical counterforce acting on the bearing shafts 8, 16 is predetermined via the piston diameter of the pistons 70, 72 and the height of the pressure in the pressure chamber 86. Since the in the FIG. 2 shown axial force components 47, 49 have a different size, the respective mechanical counterforce should also be different levels. The in FIG. 1 Upper piston 70 has, as already described, a larger diameter than the lower piston 72, whereby this has a larger pressure application surface and thus a higher pressure force on the piston 70 is transmitted as a counter force on the bearing shaft 8, if, as in the embodiment of Case is, an equal pressure on the piston 70, 72 acts. It would also be conceivable that the pistons 70, 72 have the same piston diameter and are also subjected to different pressures at a different pressure or at different piston diameters. The opposing forces are smaller than the axial forces 47, 49, so that with a resultant force, the gears 10, 12 are pressed against the bearing body 28 and this to the housing cover 4.

By acting on the gears 10, 12 via the bearing shafts 8, 16 mechanical counterforce of the rest of the axial force is introduced bypassing the bearing body 28 in the housing 2.

FIG. 3 shows a plan view of the axial surfaces 34, 36 of the gears 10, 12 of a further embodiment, wherein the application of the gears 10, 12 is explained with an opposing hydraulic force in the following. In the FIG. 3 the helical gearing 14 is clearly visible. For pressurizing the gears 10, 12 with a hydraulic counterforce against the respective Axialkraftkomponente 49 FIG. 2 , in the axial surfaces 34 and 36 of the gears 10 and 12 each have a pressure pocket 50 and 52, respectively. The pressure pockets 50, 52 each define with the first bearing body 28 FIG. 1 a pressure field which is in pressure fluid communication with the high pressure of the gear machine 1. The pressure pocket 52 of the gear 12 is formed as an annular groove 52 which is circumferentially introduced into the axial surface 36 between tooth end faces 53 of teeth 54 of the gear 12 and an outer circumferential surface of the bearing shaft 16. The pressure pocket 50 of the gear 10 has in addition to an annular groove corresponding to the pressure pocket 52 in the toothed end faces 53 inserted tooth pocket sections 56, whereby the pressure pocket 50 is thus introduced over a large area in the axial surface 34 and in its extent greater than the pressure pocket 52. The pressure pocket 50 is then bounded radially with a wall 58 running around the circumference of the gearwheel 14.

The driving gear 10 has a larger axial force component 47, see FIG. 2 By the opposite of the pressure pocket 52 larger pressure pocket 50 a larger pressure application surface for the high pressure of the gear machine 1 is provided on the gear 10 so that corresponding to the higher Axialkraftkomponente 47 a higher counterforce on the gear 10 acts as on the gear 12th

The counterforces applied to the gears 10, 12 via the pressure pockets 50, 52 are, as explained above, less than or equal to the respective axial force components 47, 49 FIG. 2 , As a result, the sliding friction between the gears 10, 12 and the bearing body 28 is reduced, whereby wear is minimized. The counterforce thus acts as Axialkraftkompensation on the gears 10, 12. The force resulting from the Axialkraftkomponenten 47, 49 and the opposing forces then serve for Axialspaltkompensation the sliding gap between the gears 10, 12 and the bearing body 28 (provided that the resultant force is not Zero). On the housing cover 4 facing end face of the bearing body 28 are no measures for the compensation of an axial gap between the gears 10, 12 and the bearing bodies 26, 28 necessary, so that here a very simple production is possible without much processing.

The Indian FIG. 1 Right bearing body 26 is acted upon by no force resulting from the Axialkraftkomponenten and the counter forces. The sliding gap between the gears 10, 12 and the bearing body 26 is compensated for independently of the Axialkraftkomponenten and the opposing forces between the gears 10, 12 and the bearing body 28 in a conventional manner.

FIG. 4 shows the gears 10, 12 off FIG. 1 facing end face 39 of an in FIG. 1 left spectacle-shaped bearing body 28 of a third embodiment. The bearing body 28 may, as in the FIG. 4 be formed in two parts. All around one in the FIG. 4 Upper bearing eye 60 is introduced into the end face 39 of the bearing body 28, a first annular pressure groove 62. A second pressure groove 64 is formed around the lower bearing eye 66 of the bearing body 28 substantially in the high pressure region of the gear machine 1, encompassing a partial circle. The pressure grooves 62, 64 are via radial grooves 68 to the high pressure of the gear machine 1 in fluid communication. The pressure groove 62 forms a first pressure field and the pressure groove 64 forms a second pressure field that is smaller than the first pressure field. The different sized axial forces 47, 49 thus counteract here also different sized counter forces.

In the embodiments of the Figures 3 and 4 is the Axialkraftkompensation between the gears 10, 12 and the bearing bodies 28 thus implemented with very little device complexity. For example, no additional components are needed, resulting in low manufacturing costs. The internal hydraulic pressure forces of the gear machine 1 can be used directly for Axialkraftkompensation, whereby they are directly coupled to the operating conditions of the gear machine 1. Here, the bearing body 28 is under the action of the entire axial force on the cover 4.

The mode of action of the above-described Axialspalt- and Axialkraftkompensation is independent of the type of bearing elements used and is therefore applicable to all, suitable for the axial sealing of gear machines components. The same applies to the type of gearing and its parameters. Such Axialspalt- and Axialkraftkompensation can be used both in external and internal gear machines.

The gear machine can be used as a gear pump or motor.

Disclosed is a gear machine with a housing for receiving two intermeshing gears. These are mounted slidably axially with axial surfaces between housed in the housing bearing bodies and radially, each with a bearing shaft accommodated in the bearing bodies. During operation of the gear machine, an axial force component of a force resulting from the operation of hydraulic and mechanical forces acts in the same axial direction on one gear in each case. The gear wheels and / or bearing shafts are each acted upon counter to the respective Axialkraftkomponente with a counter force which is equal to or less than / as the amount of the respective Axialkraftkomponente.

Claims (16)

1. Toothed wheel machine having a housing (2) for accommodating two intermeshing toothed wheels (10, 12), in particular helically toothed wheels, which are supported in a sliding manner axially by axial surfaces (30, 32, 34, 36) between bearing bodies (26, 28) accommodated in the housing (2) and radially by respective bearing shafts (8, 16) accommodated in the bearing bodies (26, 28), in which an axial force component (47, 49) of a force resulting from hydraulic and mechanical forces arising during operation of the toothed wheel machine (1) acts on each toothed wheel (10, 12) in the same axial direction, characterized in that a counter-force against the respective axial force component (47, 49) is applied to the toothed wheels (10, 12) and/or bearing shafts (8, 16), the magnitude of each counter-force being less than that of the respective axial force component (47, 49).
2. Toothed wheel machine according to Claim 1, wherein the toothed wheels (10, 12) are helically toothed.
3. Toothed wheel machine according to Claim 1 or 2, wherein the first bearing body or bodies (28), which lies or lie in the direction of the effective axial force component (47, 49), is/are pressed against a housing cover (4) of the housing (2) mechanically by way of the toothed wheels (10, 12) and/or hydraulically by way of a pressure force.
4. Toothed wheel machine according to Claim 3, wherein a hydraulic pressure is applied to the second bearing body or bodies (26) at an end face (38) on the housing side, said face facing away from the toothed wheels (10, 12).
5. Toothed wheel machine according to one of the preceding claims, wherein the counter-force is a pressure force and/or a mechanical force.
6. Toothed wheel machine according to one of the preceding claims, wherein the counter-force acts on the at least one toothed wheel (10, 12) by means of a pressure field between at least one toothed wheel (10, 12) and the first bearing body or bodies (28).
7. Toothed wheel machine according to Claim 6, wherein a pressure pocket (50, 52) is introduced into that axial surface (34, 36) of at least one toothed wheel (10, 12) which faces the first bearing body (bearing bodies) (28) in order to delimit the pressure field.
8. Toothed wheel machine according to Claim 7, wherein the axial surface (34, 36) of one toothed wheel (10, 12) consists of tooth end faces (53) and of an annular surface, and the pressure pocket (50, 52) comprises at least one annular groove (50, 52) introduced into the annular surface and running approximately concentrically around a longitudinal axis of the corresponding toothed wheel (10, 12).
9. Toothed wheel machine according to Claim 8, wherein the pressure pocket (50, 52) is enlarged by tooth pocket sections (56) introduced into the tooth end faces (53) of toothed wheel (10).
10. Toothed wheel machine according to Claim 9, wherein the annular groove (52) is introduced into that axial surface (36) of the driven toothed wheel (12) which faces the first bearing body (bearing bodies) (28), and the pressure pocket (50) together with the tooth pocket sections (56) is introduced into that axial surface (34) of the driving toothed wheel (10) which faces the first bearing body (bearing bodies) (28).
11. Toothed wheel machine according to one of Claims 7 to 10, wherein the pockets (50, 52, 56) are in pressure-medium communication with a high pressure of the toothed wheel machine (1).
12. Toothed wheel machine according to Claim 6, wherein a pressure groove (62, 64) running at least partially around a bearing eye (60, 66) is introduced into that end face (39) of the first bearing body (bearing bodies) (28) which faces the toothed wheels (10, 12).
13. Toothed wheel machine according to Claim 12, wherein that end face (39) of the first bearing body (bearing bodies) (28) which faces the toothed wheels (10, 12) has introduced into it a first pressure groove (62), running once concentrically all the way round a first bearing eye (60), and a second pressure groove (64), spanning a partial circle around a second bearing eye (66), and wherein the pressure grooves (62, 64) are in pressure-medium communication with the high pressure of the toothed wheel machine (1) via a pressure-medium port (68).
14. Toothed wheel machine according to one of Claims 3 to 13, wherein, for each bearing shaft (8, 16), there is a piston (70, 72) supported in a sliding manner in the housing cover (4) of the housing (2), approximately coaxially with respect to the toothed wheel longitudinal axis, for applying force to the bearing shafts (8, 16), and wherein the respective piston (70, 72) rests by means of a first piston end face (74, 76) against a shaft end face (78, 80) of the bearing shaft (8, 16) which faces in the direction of the axial force component, and wherein pressure is applied to a second piston end face (82, 84) of the respective piston (70, 72).
15. Toothed wheel machine according to Claim 14, wherein the two pistons (70, 72) have pressure application areas of different sizes in comparison with one another.
16. Toothed wheel machine according to Claim 15, wherein the second piston end faces (82, 84) of the pistons (70, 72) are connected to the high pressure of the toothed wheel machine (1).

Images