Gear for a geared fluid machine, process for manufacturing such a gear, and geared fluid machine

Abstract

The invention relates to a gear (3, 4) for a geared fluid machine (1), comprising toothing (7, 8) which has multiple teeth (17) and is designed as external toothing (7) or as internal toothing (8). According to the invention, a tooth tip recess (27) which is closed around the edges is formed in a tooth tip (23) of at least one of the teeth (17), and / or a tooth base recess (31) which is closed around the edges is formed in at least one tooth base (24) located between two of the teeth (17). The invention further relates to a process for manufacturing a gear (3, 4) for a geared fluid machine (1) and to a geared fluid machine (1).

Description

[0001] DESCRIPTION

[0002] Gear for a gear fluid machine, method for producing such a gear and gear fluid machine

[0003] The invention relates to a gear for a gear fluid machine, having a multi-tooth gearing configured as an external or internal gearing. The invention further relates to a method for producing such a gear and to a gear fluid machine having such a gear.

[0004] From the prior art, for example, the document DE 10 2016 207 093 B4 is known. This describes a gear fluid machine with a pinion having a first toothing configured as an external toothing, and with a ring gear mounted eccentrically about a ring gear axis of rotation and with respect to the pinion, which ring gear has a second toothing configured as an internal toothing that meshes partially with the first toothing, or with a first gear having an external toothing forming the first toothing, and with a second gear having the second toothing configured as an external toothing that meshes partially with the first toothing, wherein the first toothing has a plurality of first teeth and the second toothing has a plurality of second teeth.It is provided that the first toothing and / or the second toothing are designed in such a way that a line of engagement of the two toothings has at least one curved region, so that an extended line of engagement is obtained.

[0005] The object of the invention is to propose a gear for a gear fluid machine which has advantages over known gears, in particular enabling an optimized pressure build-up and pressure reduction in the gear fluid machine.

[0006] This is achieved according to the invention with a gear for a gear fluid machine having the features of claim 1. It is provided that a tooth tip recess with a closed edge is produced in a tooth tip of at least one of the teeth and / or a tooth base recess with a closed edge is produced in at least one tooth base present between two of the teeth.

[0007] Advantageous embodiments with useful further developments of the invention are specified in the dependent claims. It should be noted that the exemplary embodiments explained in the description are not limiting; rather, any variations of the features disclosed in the description, the claims, and the figures are feasible.

[0008] The gear preferably represents a component of the gear fluid machine, but can of course also be present separately. The gear fluid machine represents a fluid conveying device and thus serves to convey a fluid, for example, a liquid or a gas. For this purpose, the gear fluid machine has two gears, namely a first gear and a second gear. The first gear, the second gear, or both the first gear and the second gear are preferably (each) designed according to the gear described here. The gear fluid machine itself can, in principle, be designed in any desired manner; in particular, it is an external gear fluid machine or an internal gear fluid machine.

[0009] In the case of an external gear fluid machine, both gears have external teeth that mesh with each other in an engagement region. If the gear fluid machine is an internal gear fluid machine, the first gear has external teeth and the second gear has internal teeth, or vice versa. In this case, the first gear can also be referred to as a pinion and the second gear as a ring gear. The teeth of the two gears mesh with each other in some areas in the circumferential direction, i.e., they mesh with each other in some areas, namely in an engagement region. Regardless of the design of the gear fluid machine, the two gears are intended for fluid conveyance and are therefore designed such that they interact during a rotary movement to convey the fluid, engaging or meshing with each other.This means that a rotational movement of the first gear is transmitted directly to the second gear and vice versa, a rotational movement of the second gear is transmitted directly to the first gear.

[0010] Both the first gear and the second gear are preferably arranged in a machine housing of the gear fluid machine and rotatably mounted therein. The first gear is rotatably mounted about a first axis of rotation, whereas the second gear is rotatably mounted about a second axis of rotation. In the internal gear fluid machine, viewed in cross-section, i.e. in a sectional plane perpendicular to the axes of rotation, the first gear is arranged in the second gear, namely in such a way that the toothing, in particular external toothing, of the first gear meshes or is in engagement with the toothing, in particular internal toothing, of the second gear in the engagement region. In the context of this description, reference is mainly made to the design of the gear fluid machine as an internal gear fluid machine by way of example.However, the described gear can be used in any gear fluid machine, especially for external gear fluid machines. The explanations are therefore always transferable analogously to a gear fluid machine designed as an external gear fluid machine.

[0011] The engagement region is, for example, fixed to the housing and therefore does not rotate with the first gear or the second gear. In the engagement region, a tooth of one of the gears engages in a tooth space of the other of the gears. The tooth space is circumferentially delimited by teeth of the respective gear. For example, a tooth of the first gear engages in a tooth space of the second gear, or conversely, a tooth of the second gear engages in a tooth space of the first gear. In the engagement region, the first gear and the second gear interact to form a seal.

[0012] On the other side of the engagement region, i.e. preferably on the side diametrically opposite the engagement region with respect to the first axis of rotation and / or the second axis of rotation, a filler piece, for example, is arranged. The filler piece is located between the first gear and the second gear, or in other words between the external toothing of the first gear and the internal toothing of the second gear. The filler piece is thus arranged in a fluid chamber which is bounded radially inwards by the first gear and radially outwards by the second gear, in each case with respect to the first axis of rotation and the second axis of rotation. The filler piece rests on the one hand against the first toothing and on the other hand against the second toothing.More precisely, the filler piece sealingly engages the tooth tips of the first toothing and the tooth tips of the second toothing, dividing the fluid space into a first fluid chamber and a second fluid chamber. Each of the two fluid chambers is thus circumferentially delimited, on the one hand, by the filler piece and, on the other hand, by the tight meshing of the first toothing and the second toothing in the engagement area.

[0013] The filler piece is preferably designed in several parts and thus has a plurality of segments. The segments of the filler piece are arranged next to one another in the radial direction, so that a first segment is arranged on the side of a second segment facing the first gear, and conversely, the second segment is arranged on the side of the first segment facing the second gear. The first segment bears sealingly against the first gear or its external toothing, and the second segment bears sealingly against the second gear or the internal toothing of the second gear. The two segments are preferably displaceable relative to one another in the radial direction.

[0014] Particularly preferably, a gap existing between the segments is subjected to fluid pressure during operation of the gear fluid machine in such a way that the first segment is forced towards the first gear and the second segment towards the second gear, so that the segments bear sealingly against the respective gear or the tooth tips of the corresponding gearing. The gear fluid machine is thus radially compensated or gap-compensated in the radial direction. Each of the segments can be further subdivided into segments. For example, the first segment is therefore one-piece or consists of at least two segments and / or the second segment is one-piece or consists of at least two segments. These segments of the filler piece are also preferably mounted so that they can be displaced relative to one another, i.e. they can be displaced independently of one another. This achieves particularly effective gap compensation.

[0015] As an alternative to the filler piece, on the other side of the engagement region, i.e. again preferably on the side diametrically opposite the engagement region with respect to the first axis of rotation and / or the second axis of rotation, at least one tooth tip of the internal toothing and one tooth tip of the external toothing lie against one another in a sealing manner, in particular with a tip circle surface of the respective tooth delimited by the respective tip circle of the corresponding toothing. In other words, a tip circle surface of the tooth tip of the internal toothing is delimited by the tip circle of the internal toothing and a tip circle surface of the tooth tip of the external toothing is delimited by a tip circle of the external toothing. The tip circle surface of the internal toothing and the tip circle surface of the external toothing now lie against one another in a sealing manner. This in turn divides the fluid space into the first fluid chamber and the second fluid chamber.Each of the two fluid chambers is circumferentially delimited, on the one hand, by the tight contact of the tip surfaces and, on the other hand, by the tight meshing of the external and internal gears in the engagement area. This type of gear fluid machine can also be referred to as a ring gear fluid machine.

[0016] The two gears of the gear fluid machine are arranged between housing walls of the aforementioned machine housing of the gear fluid machine. For example, the gears are mounted on and / or in the machine housing, in particular on the housing walls. One of the housing walls is thus located on a first side of the gears, and a second of the housing walls is located on a second side of the gears, opposite the first side in the axial direction, so that the housing walls accommodate the gears between them in the axial direction. For example, a gap remaining between the housing walls and the gears is dimensioned so small that the housing walls ensure sufficient sealing of the fluid space or fluid chambers.

[0017] However, it is particularly preferred for a sealing disk to be arranged in the axial direction with respect to the first axis of rotation next to the first gear and the second gear, i.e. in particular between one of the housing walls and the gears, which sealing disk rests sealingly against the first gear and the second gear during operation of the gear fluid machine. For example, viewed in the axial direction, the sealing disk is only present on one side of the first gear and the second gear. However, it is preferably provided that - again viewed in the axial direction - such a sealing disk is arranged on each side of the two gears. In the context of this description, the particularly advantageous case in which multiple sealing disks are present will be explained.However, it goes without saying that the corresponding embodiments can also be used for a design of the gear fluid machine in which only a single sealing disc is part of the gear fluid machine.

[0018] The sealing disc is preferably forced in the axial direction towards the gears, for example by pressurisation, i.e. by exposure to a pressurised fluid, so that it bears sealingly against the gears. If there are several sealing discs, they are arranged on both sides of the gears in the axial direction. One of the sealing discs is therefore located on a first side of the gears and a second of the sealing discs is located on a second side of the gears opposite the first side in the axial direction, so that the sealing discs hold the gears between them in the axial direction. The sealing discs are preferably forced towards one another in the axial direction and thus each in the direction of the gears, for example by pressurisation, i.e. by exposure to the pressurised fluid, so that the sealing discs bear sealingly against the gears on opposite sides.The gear fluid machine is therefore axially compensated or gap-compensated in the axial direction. This results in particularly high efficiency.

[0019] Depending on the direction of rotation of the gear fluid machine, one of the fluid chambers serves as the suction chamber and the other as the pressure chamber. If the gear fluid machine is designed as a pump or is operated as a pump, fluid is supplied to the respective suction chamber, which the gear fluid machine pumps towards the pressure chamber or into the pressure chamber. The suction chamber can accordingly also be referred to as the inlet chamber and the pressure chamber as the outlet chamber; what is crucial is that the fluid is always pumped from the inlet chamber towards the outlet chamber during operation of the gear fluid machine. The pressure in the inlet chamber is always lower than the pressure in the outlet chamber when the pump is operating. Of course, however, the pressure in the inlet chamber can already be (significantly) greater than ambient pressure.For example, the gear fluid machine is used to pump pressurized fluid from the inlet chamber towards the outlet chamber.

[0020] If, however, the gear fluid machine is designed as a motor or is operated as a motor, fluid is supplied to the pressure chamber, which enters the suction chamber, causing the gears to rotate. In this case, the pressure chamber acts as the inlet chamber and the suction chamber as the outlet chamber; the pressure in the inlet chamber is higher than the pressure in the outlet chamber. This description does not explicitly address the operation of the gear fluid machine as a motor; instead, the gear fluid machine, its structure, and its function are explained for operation as a pump. Of course, use as a motor is also possible, and the explanations are analogously applicable to such a design of the gear fluid machine or such a use.

[0021] It should be noted that, for the purposes of this description, the suction chamber can also be referred to as the low-pressure chamber, and the pressure chamber as the high-pressure chamber. Analogously, the suction side of the gear fluid machine corresponds to a low-pressure side, and the pressure side to a high-pressure side. The terms "low pressure" and "high pressure" do not imply a restriction to a specific pressure level; rather, the pressure in the high-pressure chamber or on the high-pressure side is simply relatively higher than the pressure in the low-pressure chamber or on the low-pressure side.

[0022] According to the above explanations, the gear, corresponding to the first gear and / or the second gear of the gear fluid machine, has the toothing, which has a plurality of teeth and is designed either as external toothing or as internal toothing. When the toothings of the two gears mesh during operation of the gear fluid machine, at least one dead space exists, in particular in a tooth root region of the toothing, which is delimited in the circumferential direction by teeth of the toothing and in the radial direction by a tooth base located between the teeth of the toothing. The dead space or its volume is determined in particular by the tip circle and the root circle of the toothing. The dead space or a volume has a significant influence on the pressure build-up and pressure reduction during operation of the gear fluid machine and thus also on its efficiency.

[0023] Furthermore, the tip diameter of the tip circle and the root diameter of the root circle are important parameters in the design of the gear fluid machine. Typically, the aim is to design the gear fluid machine with as little space as possible and to select the tip and root diameters accordingly. However, this also influences the dead space or its volume, so this directly depends on the design of the gear fluid machine and its installation space. By selecting the tip diameter and / or root diameter accordingly, either the installation space or the dead space, and thus the pressure build-up and pressure reduction, can be optimized.

[0024] For this reason, an additional recess should be made in the gearwheel, which is designed with a closed edge. The recess is either located in the tooth tip of at least one of the teeth and is in this case also referred to as a tooth tip recess. Alternatively, it is produced in the tooth base, which is located between two of the teeth and consequently delimits a space between the teeth in the radial direction. In this case, the recess is referred to as a tooth base recess. Preferably, the recess is produced only in the tooth tip or only in the tooth base. However, it can also be provided that such a recess is present in both the tooth tip and the tooth base. It is of course particularly preferred that such a recess is present in several of the tooth tips, in particular in all of the tooth tips.Additionally or alternatively, a recess as described is preferably present in several of the tooth roots, preferably in all of the tooth roots. If, in the context of this description, reference is made to the at least one of the teeth, the at least one tooth or the tooth, the statements are always equivalent and transferable to one another. The same applies to the tooth root, so that the at least one of the tooth roots, the at least one tooth root and the tooth root are equivalent. The recess, i.e. the tooth tip recess or the tooth base recess, is produced with a closed edge in the tooth tip or the tooth root. This means that the respective recess engages in the tooth tip or the tooth root, forming a continuous edge. In particular, this means that the recess only partially penetrates the gear in the axial direction with respect to the axis of rotation of the gear.Preferably, the recess is spaced apart on both sides from opposite end faces of the gear, viewed in the axial direction, such that the recess does not penetrate either end face. The mouth of the recess preferably extends exclusively through the tooth tip or the tooth root, or is only produced in this. The recess is therefore designed as a groove that is closed on all sides. Particularly preferably, the recess runs straight throughout. For this purpose, it can be provided that it has - at least viewed in section - a straight longitudinal central axis, which is preferably spaced parallel to the axis of rotation of the gear. The described design of the gear makes it possible, for given toothing parameters of the toothing, in particular for a given tip circle diameter and a given root circle diameter, to increase the volume of the fluid chamber compared to a design of the gear without a recess.Accordingly, the pressure build-up and / or pressure build-up that occurs during operation of the gear fluid machine can still be influenced even with fixed gearing parameters.

[0025] A further development of the invention provides that the at least one tooth is delimited in the circumferential direction with respect to a rotational axis of the gear by two tooth flanks which are connected to one another via a tooth tip surface delimiting the tooth in the radial direction, wherein the tooth tip recess extends through the tooth tip surface to form a continuous tooth tip recess edge that is in particular spaced apart from the tooth flanks. The tooth of the gearing has a tooth tip and a tooth root, wherein the tooth tip and, at least in regions, also the tooth root are delimited in the circumferential direction by the tooth flanks. One of the tooth flanks delimits the tooth on a first side and a second of the tooth flanks on a second side opposite the first side. The two tooth flanks therefore accommodate the tooth between them in the circumferential direction.

[0026] The tooth flanks are connected to one another via the tooth tip surface, which is present at the tooth tip and delimits it in the radial direction, in particular in the radially outward direction in the case of external gearing and in the radially inward direction in the case of internal gearing. The tooth tip surface preferably corresponds to the aforementioned tip circle surface or forms part of it. The recess is designed in the tooth tip surface, namely in such a way that it has the continuous edge, which is also referred to as the tooth tip recess edge. The recess is preferably arranged at a distance from both tooth flanks in the circumferential direction, in particular it is located centrally between the tooth flanks. This achieves a particularly uniform pressure build-up and / or pressure reduction.

[0027] A further development of the invention provides that the teeth accommodating the tooth base between them are delimited on mutually facing sides by tooth flanks which are connected to one another via the tooth base, wherein the tooth base recess extends through a tooth base surface present in the tooth base to form a continuous tooth base recess edge, in particular spaced from the tooth flanks. Two teeth of the toothing each delimit a tooth space between them in the circumferential direction with respect to the axis of rotation of the gear. The tooth space is delimited in the radial direction by the tooth base, namely in the radial direction inwards in the case of external toothing and in the radial direction outwards in the case of internal toothing.

[0028] More precisely, the intertooth space is delimited in the circumferential direction by the tooth flanks of the teeth defining the intertooth space. The tooth root extends in the circumferential direction between the tooth flanks and extends up to them. The tooth flanks are connected to one another via the tooth root. The tooth base surface is located in the tooth root; in particular, the tooth base surface delimits the intertooth space in the radial direction. For example, the tooth base surface lies at least partially or completely in the root circle of the toothing. The recess is made in the tooth base surface, namely in such a way that it penetrates it, forming the edge of the tooth base recess. This edge of the tooth base recess is preferably spaced from the tooth flanks in the circumferential direction. Alternatively, however, it extends all the way to the tooth flanks.In any case, the described design of the gear allows for a targeted adjustment of the pressure build-up and / or pressure reduction.

[0029] A further development of the invention provides that the tooth tip recess is arranged centrally in the circumferential direction of the tooth tip surface and / or the tooth, and / or that the tooth base recess is arranged centrally in the circumferential direction of the tooth base surface and / or between the teeth. This configuration is, firstly, structurally simple. Secondly, the gear configured in this way can be used regardless of the intended direction of rotation. It is particularly advantageous for use in a gear fluid machine intended for reversing operation, i.e., operated temporarily in a first direction of rotation and temporarily in an opposite second direction of rotation.

[0030] A further development of the invention provides that the tooth tip recess is arranged eccentrically in the circumferential direction in the tooth tip surface and / or the tooth, and / or that the tooth base recess is arranged eccentrically in the circumferential direction in the tooth base surface and / or between the teeth. In particular, it can be provided that the tooth base recess extends circumferentially into one of the teeth, i.e., engages it circumferentially, while being spaced circumferentially from the other of the teeth. The eccentric arrangement of the recess allows optimization for a specific direction of rotation.

[0031] A further development of the invention provides that the tooth tip recess and / or the tooth base recess are arranged centrally in the axial direction between end faces of the gear. The gear is delimited in the axial direction on opposite sides by its end faces. Each of the end faces preferably lies completely in an imaginary end face plane which is perpendicular to the axis of rotation. The recess is arranged at a distance from these planes on both sides, in particular it is located centrally between them. Preferably, however, it extends over a significant portion of the gear in the axial direction, in particular over at least 50%. Preferably, it extends over at least 60%, at least 70% or at least 80% of the gear in the axial direction. Particularly preferably, the extension is even greater, for example the recess extends over at least 80%, at least 90% or at least 95% of the gear.This makes it possible to adjust the pressure build-up and / or pressure reduction particularly effectively.

[0032] A further development of the invention provides that a depth of the tooth tip recess and / or a depth of the tooth base recess increases and / or decreases, in particular continuously, at least in some regions, viewed in the axial direction. This means that the depth of the recess changes over its extension in the axial direction with respect to the axis of rotation of the gear, preferably changes continuously at least in some regions. It can be provided that the depth of the recess is constant in a center of the recess and decreases outwards in the axial direction at least on one side, but preferably on both sides, so that the recess merges smoothly into the tooth tip surface or the tooth base surface. The recess can also have a spherical design. In this case, the depth of the recess initially increases continuously in the axial direction, starting from a first side of the recess, namely up to a reversal point.This is where the greatest depth of the recess is reached in cross-section. Starting from the reversal point, the depth decreases in the axial direction up to a second side of the recess opposite the first side, namely again continuously. The reversal point is, for example, centrally between the first side and the second side of the recess. However, an off-center arrangement can also be provided. The recess is arc-shaped in this respect, with the respective recess base taking up a curve which is continuously curved. A radius of curvature of the curve can be constant over the extent of the recess in the axial direction or it can vary in the axial direction. The described design enables a comparatively small distance between the recess and the end faces of the gear without causing any structural impairment of the gear.

[0033] A further development of the invention provides that the tooth tip recess has a tooth tip recess base which merges into the tooth tip surface via a tooth tip recess wall that circumferentially delimits the tooth tip recess and forms the tooth tip recess edge, and / or that the tooth base recess has a tooth tip recess base which merges into the tooth base surface via a tooth tip recess wall that circumferentially delimits the tooth tip recess and forms the tooth tip recess edge. The tooth tip recess is therefore delimited by the tooth tip recess base in the radial direction and by the tooth tip recess wall at least in the circumferential direction, preferably additionally also in the axial direction. The same applies to the tooth base recess. This is therefore delimited in the radial direction by the tooth tip recess base and by the tooth tip recess wall at least in the circumferential direction, but preferably additionally in the axial direction.The respective wall of the recess forms the respective edge, namely by engaging the tooth tip surface or the tooth base surface. The tooth tip recess base is connected to the tooth tip surface via the tooth tip recess wall, and the tooth base recess base is connected to the tooth base surface via the tooth base recess wall. Such a gear design achieves the aforementioned advantages. A further development of the invention provides that the tooth tip recess base and / or the tooth base recess base is completely flat. In other words, the tooth tip recess base or the tooth base recess base lies completely in an imaginary plane. This enables particularly simple production of the recess, for example by milling.The extension of a planar region of the tooth tip recess base and / or the tooth base recess base extends in the axial direction preferably over at least 50%, at least 70% or at least 90% of an extension of the recess in the same direction.

[0034] A further development of the invention provides that the tooth tip recess wall forms an angle of at least 15° and at most 90° with the tooth tip recess base and / or the tooth tip surface, and / or that the tooth tip recess wall forms an angle of at least 15° and at most 90° with the tooth tip recess base and / or the tooth tip surface. The tooth tip recess wall is therefore angled at least in some regions relative to the tooth tip recess base and / or the tooth tip surface. For example, this applies to regions of the tooth tip recess wall which, viewed in the axial direction, are located at the end of the tooth tip recess. The tooth tip recess wall is therefore arranged at an angle, so that a smooth transition is achieved between the tooth tip recess base and the tooth tip surface. For example, the tooth tip recess wall is completely flat, at least in this region, i.e., lies completely in an imaginary plane.The same applies to the tooth base recess wall. The described design achieves a smooth transition and thus avoids structural weakening of the gear.

[0035] A further development of the invention provides that the tooth tip recess wall and / or the tooth base recess wall is composed of several wall segments, each of the wall segments being either continuously straight or continuously curved. The wall segments preferably adjoin one another directly. Each of the wall segments is either continuously straight or continuously curved, with the latter particularly preferably having a constant radius of curvature. For example, there are two straight and two curved wall segments, the two straight wall segments being arranged parallel to one another and the curved wall segments adjoining them at their ends and connecting them to one another. This creates a stadium-shaped recess. The described design of the gear enables the advantages already explained.

[0036] A further development of the invention provides that the tooth tip recess wall transitions into the tooth tip recess base via a curve or a chamfer, and / or that the tooth base recess wall transitions into the tooth base recess base via a curve or a chamfer. Thus, the respective wall does not run vertically into the respective base, but rather a smooth transition is implemented via the curve or chamfer. This achieves a high structural strength of the gear.

[0037] A further development of the invention provides for the tooth flanks to be involute tooth flanks. The gearing is designed as involute gearing, at least partially or completely. This means that, viewed in cross-section, the tooth flanks follow involutes, which result from the gearing parameters of the gearing. Involute gearing is particularly suitable for gear fluid machines because it enables high efficiency and low leakage losses.

[0038] The invention further relates to a method for producing a gear for a gear fluid machine, in particular a gear according to the embodiments within the scope of this description, wherein the gear has a toothing comprising a plurality of teeth, configured as an external toothing or as an internal toothing. It is provided that a tooth tip recess with a closed edge is produced in a tooth tip of at least one of the teeth and / or a tooth base recess with a closed edge is produced in at least one tooth base located between two of the teeth.

[0039] The advantages of such a procedure or such a gear design have already been pointed out. Both the gear and the method for its manufacture can be further developed according to the explanations in this description, so reference is made to these in this regard.

[0040] A further development of the invention provides that the tooth tip recess and / or the tooth base recess are produced by machining after the toothing has been formed. It is therefore provided that the toothing is first completely formed, for example, also by machining, in particular by broaching. Only when the toothing has its final shape, which it preferably also has later during operation of the gear fluid machine, is the respective recess produced. The machining used here can be milling, for example, so that the recess or the multiple recesses are individually introduced into the toothing. This enables the targeted adjustment of the volume of the dead space and, accordingly, the pressure build-up and pressure reduction.Of course, the toothing and the recess or recesses can also be produced during the same operation.

[0041] The invention also relates to a gear fluid machine, comprising a first gearwheel having a first toothing with a plurality of teeth and mounted for rotation about a first axis of rotation, in particular a gearwheel according to the embodiments in the context of this description, and a second gearwheel having a second toothing with a plurality of teeth that meshes with the first toothing in an engagement region and is mounted for rotation about a second axis of rotation different from the first axis of rotation, in particular a gearwheel according to the embodiments in the context of this description. In this case, it is provided that a tooth tip recess with a closed edge is produced in a tooth tip of at least one of the teeth and / or a tooth base recess with a closed edge is produced in at least one tooth base located between two of the teeth.

[0042] With regard to the advantages and possible advantageous further training, reference is again made to the explanations in this description.

[0043] The features and feature combinations described in the description, in particular the features and feature combinations described in the following description of the figures and / or shown in the figures, can be used not only in the respective combination specified, but also in other combinations or on their own, without departing from the scope of the invention. Thus, embodiments are also considered to be encompassed by the invention that are not explicitly shown or explained in the description and / or the figures, but which follow from or can be derived from the explained embodiments.

[0044] The invention will be explained in more detail below with reference to the exemplary embodiments shown in the drawings, without limiting the invention. In the drawings:

[0045] Figure 1 is a schematic sectional view through a gear fluid machine with a first gear and a second gear, Figure 2 is a schematic sectional view of the first gear in a first embodiment,

[0046] Figure 3 is a schematic detailed representation of a first variant of the first embodiment of the first gear,

[0047] Figure 4 is a schematic representation of a second variant of the first embodiment of the first gear,

[0048] Figure 5 is a schematic representation of a second embodiment of the first gear,

[0049] Figure 6 is a schematic detailed representation of a first variant of the second embodiment of the first gear,

[0050] Figure 7 is a schematic representation of a second variant of the second embodiment of the first gear,

[0051] Figure 8 is a schematic sectional view of the second gear in a first embodiment,

[0052] Figure 9 is a schematic detailed view of a first variant of the first embodiment of the second gear,

[0053] Figure 10 is a schematic representation of a second variant of the first embodiment of the second gear,

[0054] Figure 11 is a schematic representation of a second embodiment of the second gear,

[0055] Figure 12 is a schematic detailed representation of a first variant of the second

[0056] Design of the second gear,

[0057] Figure 13 is a schematic representation of a second variant of the second embodiment of the second gear,

[0058] Figure 14 is a schematic sectional view of a recess produced in the first gear in a first variant, and Figure 15 is a schematic sectional view of the recess in a second variant.

[0059] Figure 1 shows a schematic cross-sectional view of a gear fluid machine 1, which here is an internal gear fluid machine and has a machine housing 2 in which a first gear 3 and a second gear 4 are rotatably mounted. The first gear 3 can also be referred to as a pinion and the second gear 4 as a ring gear. The first gear 3 is rotatably mounted in the machine housing 2 about a first axis of rotation 5 and the second gear 4 about a second axis of rotation 6. It can be seen that the first axis of rotation 5 and the second axis of rotation 6 are arranged parallel and spaced from one another, so that the first gear 3 and the second gear 4 have different axes of rotation. The first gear 3 has a first toothing 7 designed as an external toothing and the second gear 4 has a second toothing 8 designed as an internal toothing, which mesh with one another in an engagement region 9, i.e., are in engagement with one another.

[0060] The first gear 3 and the second gear 4 together delimit a fluid chamber 10. The first gear 3 delimits the fluid chamber 10 in the radially inward direction and the second gear 4 in the radially outward direction. The fluid chamber 10 is circumferentially divided into a first fluid chamber 12 and a second fluid chamber 13 by the meshing of the gears 3 and 4 on the one hand and a filler piece 11 on the other. Depending on the direction of rotation of the gear fluid machine 1, one of the fluid chambers 12 and 13 is present as a suction chamber and another of the fluid chambers 12 and 13 is present as a pressure chamber. The filler piece 11 is designed in several parts and has a plurality of segments 14 and 15. Between the segments 14 and 15 there is a gap 16 which can be pressurized with fluid. This fluid pressure forces segments 14 and 15 toward the respective gears 3 and 4, respectively. This results in radial compensation of the gear fluid machine 1.

[0061] Figure 2 shows a schematic representation of the first gear 3 in a first embodiment. It is clear that the external toothing 7 of the first gear 3 has a plurality of teeth 17, between each of which there is a tooth gap 18. Each of the tooth gaps 18 is delimited in the circumferential direction with respect to the first axis of rotation 5 by two of the teeth 17. The external toothing 7 is characterized by a plurality of toothing parameters, in particular a root circle diameter of a root circle 19 and a tip circle diameter of a tip circle 20. The teeth 17 each extend in the radial direction from the inside to the outside, starting from the root circle 19 up to the tip circle 20. Each of the teeth 17 is delimited in the circumferential direction by two tooth flanks 21 and 22 and has a tooth tip 23. The two tooth flanks 21 and 22 are connected to one another in the radial direction on the outside via a tooth tip surface 24 of the respective tooth tip 23.The tooth tip surface 24 preferably runs along the tip circle 20. In the radial direction, the tooth flanks 21 and 22 are connected by a tooth base 25, more precisely, a tooth base surface 26. The tooth base 25 or the tooth base surface 26 preferably run along the root circle 19.

[0062] In the external toothing 7 shown here, a tooth tip recess 27 is produced in the tooth tip 23. The tooth tip recess 27 extends through the tooth tip surface 24, forming a continuous tooth tip recess edge 28. This means that the tooth tip recess edge 28 is continuous in the tooth tip surface 24 and is in particular spaced from the end faces of the gear 7. Preferably, the tooth tip recess 27, as shown here, is arranged centrally in the circumferential direction in the tooth 17 or the tooth tip 23. It has a depth which corresponds to at least 5%, at least 10%, or at least 15% of a tooth height of the tooth 17, i.e. a difference between the tip circle diameter and the root circle diameter.

[0063] Figure 3 shows a first variant of the first embodiment of the first gear 3. It can be seen that the tooth tip recess 27 is essentially stadium-shaped. It has a tooth tip recess base 29 and a tooth tip recess wall 30, wherein it is bounded radially inward by the tooth tip recess base 29 and by the tooth tip recess wall 30 both circumferentially and axially. The tooth tip recess wall 30 is essentially perpendicular to the tooth tip recess base 29 and the tooth tip surface 24.

[0064] Figure 4 shows a second variant of the first embodiment of the first gear 3. In contrast to the first variant, the tooth tip recess 27 has a substantially rectangular configuration, wherein the tooth tip recess wall 30 is angled on the inside in the axial direction in order to achieve a smooth transition into the tooth tip surface 24.

[0065] Figure 5 shows a second embodiment of the first gear 3. In contrast to the first embodiment, there is now not the tooth tip recess 27, but a tooth base recess 31. The tooth base recess 31 penetrates the tooth base surface 26 and, in the example shown here, extends in the circumferential direction from the tooth flank 21 to the tooth flank 22. The tooth base recess 31 penetrates the tooth base surface 26, forming a continuous tooth base recess edge 32. This in turn means that the tooth base recess edge 32 is produced continuously in the tooth base surface 26 and the tooth base recess 31, in particular, does not penetrate the end faces of the gear 3.

[0066] Figure 6 shows a schematic representation of a first variant of the second embodiment of the first gear 3. Analogous to the first variant of the first embodiment, the tooth base recess 31 is stadium-shaped and is delimited in the radial direction inwards by a tooth base recess base 33 and in the circumferential direction and in the axial direction by a tooth base recess wall 34.

[0067] Figure 7 shows a second variant of the second embodiment of the first gear 3. Here again, a substantially rectangular shape of the tooth base recess 31 is provided, analogous to the second variant of the first embodiment.

[0068] Figure 8 shows a first embodiment of the second gear 4 with the internal toothing 8. Express reference is made to the above statements regarding the first gear 3; the corresponding definitions are also used here and apply analogously. In addition to the root circle 19 and the tip circle 20, a base circle 35 is also indicated, up to which the tooth flanks 21 and 22 extend radially outward. Analogous to the first embodiment of the first gear 3, a tooth tip recess 27 is formed in the tooth tip 23 of the tooth 17, which is delimited by a tooth tip recess edge 28.

[0069] Figure 9 shows a first variant of the first embodiment of the second gear 4. Reference is made in full to the explanations regarding the first variant of the first embodiment of the gear 3.

[0070] Figure 10 shows a second variant of the first embodiment of the second gear 4. Here, too, reference is made to the explanations regarding the second variant of the first embodiment of the first gear 3.

[0071] Figure 11 shows a second embodiment of the second gear 4. Analogous to the second embodiment of the first gear 3, a tooth base recess 31 is provided instead of the tooth tip recess 27. Reference is made to the above explanations for further explanation.

[0072] Figure 12 shows a first variant of the second embodiment of the second gear 4, and Figure 13 shows a second variant of the second embodiment of the second gear 4. Reference is made to the explanations regarding the first variant and the second variant of the second embodiment of the first gear 3. As an alternative to the embodiment shown, the tooth base recess can of course also extend in the circumferential direction on both sides up to the teeth 17 or the tooth flanks 21 and 22, as was also described for the second embodiment of the first gear 3, in particular for the first variant and the second variant.

[0073] Figure 15 shows a cross-sectional view through the gear 3 or 4 in the area of ​​the tooth tip recess 27 for the first variant of the various embodiments. In this variant, the tooth tip recess wall 30 is perpendicular to the tooth tip surface 24 and the tooth tip recess base 29.

[0074] Figure 15 shows a cross-sectional view through the gear 3 or 4 in the region of the tooth tip recess 27 for the second variant of the various embodiments. The explanations can be applied analogously to the tooth base recess 31. It can be seen that the tooth tip recess base 29 transitions into the tooth tip surface 24 via the tooth tip recess wall 30. A transition between the tooth tip recess base 29 and the tooth tip recess wall 30 is implemented here, for example, via a curvature 36. Both the tooth tip recess base 29 and the tooth tip recess wall 30 are completely flat apart from the curvature 36, with the tooth tip recess wall 30 being angled with respect to the tooth tip recess base 29, in particular enclosing an angle with it that is at least 15° and at most 90°.

[0075] Of course, both the tooth tip recess 27 and the tooth base recess 31 can be present on one and the same gear 3 or 4, in particular on each of the respective teeth 17. The described design of the gears 3 and 4 enables a targeted adjustment of the pressure build-up and pressure reduction during operation of the gear fluid machine 1. LIST OF REFERENCE SYMBOLS

[0076] 1 gear fluid machine

[0077] 2 machine housings

[0078] 3 1. Gear

[0079] 4 2nd gear

[0080] 5 1. Axis of rotation

[0081] 6 2nd axis of rotation

[0082] 7 1. Gearing

[0083] 8 2. Gearing

[0084] 9 Intervention area

[0085] 10 Fluid chamber

[0086] 11 Filler piece

[0087] 12 1. Fluid chamber

[0088] 13 2. Fluid chamber

[0089] 14 segments

[0090] 15 segments

[0091] 16 gap

[0092] 17 tooth

[0093] 18 Interdental space

[0094] 19 Foot circle

[0095] 20 head circle

[0096] 21 Tooth flank

[0097] 22 tooth flank

[0098] 23 Tooth head

[0099] 24 Tooth head surface

[0100] 25 Tooth base

[0101] 26 Tooth base

[0102] 27 Tooth head recess

[0103] 28 Tooth head recess edge

[0104] 29 Tooth head recess base

[0105] 30 Tooth head recess wall

[0106] 31 Tooth base recess

[0107] 32 Tooth base recess edge Tooth base recess bottom Tooth base recess wall Base circle Curvature

Claims

CLAIMS 1. Gear (3, 4) for a gear fluid machine (1), with a toothing (7, 8) having a plurality of teeth (17) and designed as an external toothing (7) or as an internal toothing (8), characterized in that an edge-closed tooth tip recess (27) is produced in a tooth tip (23) of at least one of the teeth (17) and / or an edge-closed tooth base recess (31) is produced in at least one tooth base (24) present between two of the teeth (17).

2. Gear according to claim 1, characterized in that the at least one tooth (17) is delimited in the circumferential direction with respect to an axis of rotation (5, 6) of the gear (3, 4) by two tooth flanks (21, 22) which are connected to one another via a tooth tip surface (24) delimiting the tooth (17) in the radial direction, wherein the tooth tip recess (27) passes through the tooth tip surface (24) to form a continuous tooth tip recess edge (28).

3. Gear according to one of the preceding claims, characterized in that the teeth (17) receiving the tooth base (25) between them are delimited on mutually facing sides by tooth flanks (21, 22) which are connected to one another via the tooth base (25), wherein the tooth base recess (31) passes through a tooth base surface (26) present in the tooth base (25) to form a continuous tooth base recess edge (32).

4. Gear according to one of the preceding claims, characterized in that the tooth tip recess (27) is arranged in the circumferential direction centrally in the tooth tip surface (24) and / or the tooth (17), and / or that the tooth base recess (31) is arranged in the circumferential direction centrally in the tooth base surface (26) and / or between the teeth (17).

5. Gear according to one of the preceding claims, characterized in that the tooth tip recess (27) and / or the tooth base recess (31) are / is arranged centrally in the axial direction between end faces of the gear (3, 4).

6. Gear according to one of the preceding claims, characterized in that a depth of the tooth tip recess (27) and / or a depth of the tooth base recess (31) increases and / or decreases at least in some regions when viewed in the axial direction.

7. Gear according to one of the preceding claims, characterized in that the tooth head recess (27) has a tooth head recess base (29) which has a Tooth head recess wall (30) which circumferentially delimits the tooth head recess (27) and forms the tooth head recess edge (28) and merges into the tooth head surface (24), and / or that the tooth base recess (31) has a tooth base recess base (33) which merges into the tooth base surface (26) via a tooth base recess wall (34) which circumferentially delimits the tooth base recess (31) and forms the tooth base recess edge (32).

8. Gear according to one of the preceding claims, characterized in that the tooth head recess base (29) and / or the tooth base recess base (33) is continuously flat.

9. Gear according to one of the preceding claims, characterized in that the tooth tip recess wall (30) encloses an angle of at least 15° and at most 90° with the tooth tip recess base (29) and / or the tooth tip surface (24), and / or that the tooth base recess wall (34) encloses an angle of at least 15° and at most 90° with the tooth base recess base (33) and / or the tooth base surface (26).

10. Gear according to one of the preceding claims, characterized in that the tooth tip recess wall (30) and / or the tooth base recess wall (34) is composed of a plurality of wall segments, each of the wall segments being either continuously straight or continuously curved.

11. Gear according to one of the preceding claims, characterized in that the tooth tip recess wall (30) merges into the tooth tip recess base (29) via a curvature (36) or a chamfer, and / or that the tooth base recess wall (34) merges into the tooth base recess base (33) via a curvature (36) or a chamfer.

12. Gear according to one of the preceding claims, characterized in that the tooth flanks (21, 22) are involute tooth flanks.

13. Method for producing a gear (3, 4) for a gear fluid machine (1), in particular a gear (3, 4) according to one or more of the preceding claims, wherein the gear (3, 4) has a toothing (7, 8) having a plurality of teeth (17) and designed as an external toothing (7) or as an internal toothing (8), characterized in that in a tooth head (23) of at least one of the teeth (17) a closed edge Tooth head recess (27) and / or in at least one tooth base (25) present between two of the teeth, a tooth base recess (31) with a closed edge is produced.

14. Method according to claim 13, characterized in that the tooth tip recess (27) and / or the tooth base recess (31) are produced by machining after the toothing (7, 8) has been formed.

15. Gear fluid machine (1), with a first gear (3) having a first toothing (7) with a plurality of teeth (17) and mounted rotatably about a first axis of rotation (5), in particular a gear according to one or more of claims 1 to 12, and a second toothing (8) having a plurality of teeth (17) meshing with the first toothing (7) in an engagement region (9) and rotatable about a first axis of rotation (5) different second axis of rotation (6) rotatably mounted second gear (4), in particular a gear (4) according to one or more of claims 1 to 12, characterized in that in a tooth tip (23) of at least one of the teeth (17) a closed-edge tooth tip recess (27) and / or in at least one tooth base (25) present between two of the teeth (17) a closed-edge tooth base recess (31) is produced.

Images