Internal gear fluid machinery

Abstract

The present invention relates to an internal gear fluid machine (1), comprising a first gear (3) having an external tooth portion (7) and supported rotatably around a first rotation axis (5), and a second gear (4) having an internal tooth portion (8) partially meshing with the external tooth portion (7) in a joining area (9), the second gear being supported rotatably around a second rotation axis (6) different from the first rotation axis, and a filling member (11) being arranged between the first gear and the second gear and away from the joining area (9), the filling member being in contact with the external tooth portion on one hand and the internal tooth portion on the other hand, so as to fix the first gear The fluid space (10) between the first gear and the second gear is divided into a first fluid chamber (12) and a second fluid chamber (13), wherein a plurality of sealing washers (26) are arranged on both sides of the first gear and the second gear in the axial direction about the first rotation axis, and they are sealed against the first gear and the second gear during the operation of the internal gear fluid machinery, and axial openings (27) are respectively formed in the sealing washers, and each fluid chamber (12, 13) is fluidically connected to the corresponding fluid connection (21, 22) of the internal gear fluid machinery through the two axial openings (27).

Description

Technical Field

[0001] The present invention relates to an internal gear fluid machine, comprising a first gear with an external tooth portion and supported so as to be rotatable around a first rotation axis, and a second gear with an internal tooth portion meshing with the external tooth portion in a joining area, the second gear being supported so as to be rotatable around a second rotation axis different from the first rotation axis, a filling piece arranged between the first gear and the second gear and away from the joining area, the filling piece abutting the external tooth portion on the one hand and the internal tooth portion on the other hand to divide the fluid space between the first gear and the second gear into a first fluid chamber and a second fluid chamber, and a housing wall of a machine housing of the internal gear fluid machine axially arranged on both sides of the first gear and the second gear relative to the first rotation axis. Background Art

[0002] DE 199 30 911 C1 is known in the prior art, for example. It describes an internal gear fluid machine for reversible operation in a closed circuit, comprising a pinion with external toothing; a ring gear (Hohlrad) with internal teeth, meshing with the pinion; and a housing; a filler element that fills the crescent-shaped space between the pinion and the ring gear, the filler element comprising two identical filler blocks. A retaining pin is disposed within the housing and supported end-on relative to the filler blocks. Axial disks are provided on both sides of the pinion. An axial pressure field is provided between the outer side of each axial disk and the relevant housing wall, while a control field is provided between the inner side of each axial disk and the pinion. At least one control groove is connected to each control field, which tapers toward its free end.

[0003] Furthermore, DE 10 2008 053 ​​318 A1 discloses a reversibly operative gear mechanism comprising a housing in which two gears are disposed. A first bearing chamber and a second bearing chamber are provided. In a first operating direction of the gear mechanism, hydraulic fluid pressure is applied to the first bearing chamber, forming a hydrostatic bearing for the gear mechanism; in an opposite, second operating direction, hydraulic fluid pressure is applied to the second bearing chamber, forming a hydrostatic bearing for the gear mechanism. A vehicle steering system is also described, comprising a hydraulic circuit, a hydraulic cylinder, and a gear mechanism operating as a pump. In its first operating direction, hydraulic pressure is applied to a first working chamber of the hydraulic cylinder, and in its second operating direction, hydraulic pressure is applied to a second working chamber. Summary of the Invention

[0004] The object of the present invention is to provide an internal gear fluid machine which has the advantage over known internal gear fluid machines that, due to the uniform filling of the fluid chamber with fluid, a higher efficiency can be achieved.

[0005] The internal gear fluid machinery of the present invention comprises:

[0006] a first gear wheel having an external toothing and being mounted rotatably about a first rotational axis, and a second gear wheel having an internal toothing meshing with the external toothing in a joining region and being mounted rotatably about a second rotational axis different from the first rotational axis, wherein:

[0007] a filling piece arranged between the first gear and the second gear, remote from the joining region, the filling piece being in contact with the outer toothing on one hand and the inner toothing on the other hand, so as to divide the fluid space between the first gear and the second gear into a first fluid chamber and a second fluid chamber, and,

[0008] - a housing wall of the machine housing of the internal gear fluid machine, which is arranged on both sides of the first gear and the second gear in the axial direction relative to the first rotation axis,

[0009] A connecting channel, each formed in the two housing walls, via which the same fluid chamber is fluidically connected to the same fluid connection of the internal gear turbomachine.

[0010] In this case, a connecting channel is formed in each of the two housing walls, and the same fluid chamber is fluidically connected to the same fluid connection of the internal gear turbomachine via the two connecting channels.

[0011] An internal gear fluid machine is a fluid transmission device used to transport fluids, such as liquids or gases. It comprises two gears: a first gear and a second gear. The first gear can also be called a pinion, and the second gear is also called a ring gear. The pinion has external teeth, and the ring gear has internal teeth. The external and internal teeth partially engage with each other in the circumferential direction, that is, they partially mesh with each other in the meshing area. The two gears are used to transport fluids and are therefore designed to cooperate with each other during the rotational motion for transporting fluids and to mesh with each other.

[0012] The first gear is preferably coupled to the input shaft or drive shaft of the internal gear turbomachine, preferably rigidly and / or removably or permanently. In the case of a removable coupling, for example, there is a plug-in pinion that is plugged onto the drive shaft and can be removed without causing damage. The plug-in pinion preferably has an internal toothing that cooperates with the external toothing of the input shaft to provide a transmission coupling between the plug-in pinion and the input shaft. For example, the first gear is rotatably mounted in the machine housing of the internal gear turbomachine via the input shaft. The first gear is preferably arranged on the input shaft so that it always rotates at the same speed as the input shaft during operation of the internal gear turbomachine.

[0013] Both the first and second gears are disposed in a machine housing and are rotatably supported therein. The first gear is rotatably supported about a first rotational axis, and the second gear is rotatably supported about a second rotational axis. The first rotational axis can also be referred to as the pinion rotational axis, and the second rotational axis can also be referred to as the ring gear rotational axis. Viewed in cross-section, i.e., perpendicular to the rotational axis, the first gear is disposed within the second gear. Specifically, the external teeth of the first gear mesh with or engage with the internal teeth of the second gear in a meshing region. This means that the rotational motion of the first gear is directly transmitted to the second gear, and vice versa.

[0014] The joining region is, for example, fixed to the housing and does not rotate with the first or second gear. In the joining region, the teeth of one toothing engage in the tooth gaps of the other toothing. The tooth gaps are circumferentially delimited by the teeth of the respective toothings. For example, the teeth of the inner toothing engage in the tooth gaps of the outer toothing, or vice versa. In the joining region, the inner and outer toothings work together in a sealing manner.

[0015] A filler element is provided on the other side of the joining region, preferably on the side of the joining region diametrically opposite the first and / or second rotational axes. The filler element is located between the first and second gears, or in other words, between the outer teeth of the first gear and the inner teeth of the second gear. Thus, the filler element is disposed within a fluid chamber that is bounded radially inwardly by the first gear and radially outwardly by the second gear relative to the first and / or second rotational axes, respectively.

[0016] The filler piece rests against the outer toothing on the one hand and the inner toothing on the other. More precisely, the filler piece rests sealingly against the tooth heads of the outer and inner toothings to divide the fluid chamber into a first fluid chamber and a second fluid chamber. Each fluid chamber, viewed from the circumference, is delimited on the one hand by the filler piece and on the other hand by the mutual engagement of the outer and inner toothings in the engagement region.

[0017] Depending on the direction of rotation of the internal gear fluid machine, one of the fluid chambers serves as a suction chamber and the other as a pressure chamber. If the internal gear fluid machine is implemented as a pump or operates as a pump, the fluid is input into the corresponding suction chamber, and the internal gear fluid machine transports the fluid in the direction of the pressure chamber or into the pressure chamber. If the internal gear fluid machine is driven as a motor, the fluid is input into the pressure chamber and enters the suction chamber under the action of the rotational movement of the gear. Within the scope of this specification, the operation of the internal gear fluid machine as a motor is not explicitly discussed, but the internal gear fluid machine operating as a pump and its functions are described. Of course, application as a motor is also possible and the implementation and application of the internal gear fluid machine here can also be applied similarly to the implementation as a motor.

[0018] The filler piece is preferably constructed in multiple parts and has a plurality of sections. The sections of the filler piece are arranged radially adjacent to each other, so that the first section is arranged on the side of the second section facing the first gear, and conversely, the second section is arranged on the side of the first section facing the second gear. The first section rests sealingly against the first gear or its external toothing, and the second section rests sealingly against the second gear or its internal toothing.

[0019] Preferably, the two segments are radially displaceable relative to each other. Particularly preferably, during operation of the internal gear fluid machine, fluid pressure is applied to the gap between the two segments in such a way that the first segment is squeezed in the direction of the first gear and the second segment is squeezed in the direction of the second gear, so that the corresponding segments are sealed against the corresponding gear or the tooth head of the corresponding tooth portion. This allows the internal gear fluid machine to be radially compensated or to compensate for radial clearance. Each segment can be further divided into segments. For example, the first segment can be one-piece or consist of at least two segments and / or the second segment can be one-piece or consist of at least two segments. These segments of the filler piece are also preferably supported so as to be displaceable relative to each other, that is, they can be displaced independently of each other. This allows very effective clearance compensation.

[0020] An internal gear fluid machine has a machine housing. Two gears of the internal gear fluid machine are disposed between housing walls of the machine housing. Thus, one of the housing walls is located on a first side of the gear, and the second housing wall is located on a second side of the gear axially opposite the first side. As a result, the housing walls accommodate the gears therebetween, viewed axially. In particular, the gap remaining between the housing walls and the gears is very small, enabling the housing walls to adequately seal the fluid space or fluid chamber. The gears are supported, for example, on and / or within the machine housing.

[0021] Connecting channels are formed in the housing walls. This means that each of the housing walls has one such connecting channel. The fluid chambers of the internal gear fluid machine are fluidically connected to the fluid connections of the internal gear fluid machine via these connecting channels, preferably permanently. Therefore, each connecting channel is fluidically located between the corresponding fluid chamber and the corresponding fluid connection, thereby forming a fluid connection between the fluid chamber and the fluid connection via the two connecting channels. These connecting channels are fluidically located parallel between the fluid chamber and the fluid connection, allowing fluid to flow simultaneously from the fluid connection to the fluid chamber and vice versa via both connecting channels.

[0022] Therefore, it is not considered to connect different fluid chambers to the same fluid connection part or to connect the same fluid chamber to different fluid connections via the connecting channel. More precisely, the connecting channel is used to establish a fluid connection between a fluid chamber and a fluid connection part. Accordingly, during the operation of the internal gear fluid machine, the fluid flows in or out simultaneously through the connecting channel. This makes it possible to achieve a very high fluid flow rate of the internal gear fluid machine. Fluid connection is generally understood to be a fluid connection that flows only through the internal gear fluid machine, that is, not through an external connection. In particular, the fluid connection runs only through the connecting channel and optionally through one or more axial openings (Axialdurchbrüche) provided in one or more optional sealing washers.

[0023] In principle, the fluid chamber connected to the fluid connection via the connecting channel can be configured as a first fluid chamber or a second fluid chamber. Accordingly, these fluid chambers can be suction chambers or pressure chambers, so that during operation of the internal gear fluid machine, the connecting channel can serve as a fluid inlet to the suction chamber or as a fluid outlet from the pressure chamber. In each case, very low fluid resistance to fluid inflow or outflow can be achieved.

[0024] According to a further development of the present invention, at least one sealing washer is arranged adjacent to the first and second gears in the axial direction relative to the first rotational axis. The sealing washer seals against the first and second gears during operation of the internal gear fluid machine. An axial opening is formed in the sealing washer, through which one of the fluid chambers is fluidically connected to one of the fluid connections of the internal gear fluid machine. For example, the sealing washer may be present only on one side of the first and second gears, viewed axially. However, such sealing washer is preferably provided on both sides of both gears, viewed axially. Within the scope of this description, the highly advantageous case of having multiple sealing washer will often be described. However, corresponding embodiments can of course also be applied to the case of an internal gear fluid machine having only one sealing washer.

[0025] Viewed axially, the sealing washer is located on one side of the gear. During operation of the internal gear fluid machine, the sealing washer is sealingly seated on the gear. Preferably, the sealing washer is pressed axially toward the gear, for example, by applying pressure, i.e., by applying a pressurized fluid. If there are multiple sealing washers, these are arranged axially on both sides of the gear. Thus, one sealing washer is located on a first side of the gear, and the second sealing washer is located on a second side of the gear axially opposite the first side, so that, viewed axially, the sealing washers accommodate the gear between them. During operation of the internal gear fluid machine, the sealing washers are sealingly seated on the gear. Preferably, the sealing washer is pressed axially toward the gear, for example, by applying pressure, i.e., by applying a pressurized fluid. This provides axial compensation or axial play compensation for the internal gear fluid machine. This achieves a very high efficiency of the internal gear fluid machine.

[0026] An axial opening is formed in the sealing washer. If there are multiple sealing washers, one axial opening is formed in each sealing washer. In other words, each sealing washer has one such axial opening, so that there are multiple axial openings in the multiple sealing washers overall. One of the fluid chambers is fluidically connected to one of the fluid connections of the internal gear fluid machine via one or more axial openings, preferably permanently. Therefore, the axial opening, or each of the axial openings, is located fluidically between the corresponding fluid chamber and the corresponding fluid connection, so that the fluid connection between the fluid chamber and the fluid connection is achieved via the axial opening or two axial openings.

[0027] Therefore, it is not possible to connect different fluid chambers to the same fluid connection via one or more axial openings, or to connect the same fluid chamber to different fluid connections. Rather, one or more axial openings serve to establish a fluid connection between a fluid chamber and a fluid connection. Accordingly, during operation of the internal gear fluid machine, fluid flows in or out via the axial openings, or simultaneously via multiple axial openings. This allows for a very high fluid throughput of the internal gear fluid machine.

[0028] In principle, a fluid chamber fluidically connected to the fluid connection via one or more axial openings can be configured as a first fluid chamber or a second fluid chamber. Accordingly, these fluid chambers can be suction chambers or pressure chambers, so that during operation of the internal gear fluid machine, one or more axial openings can serve as a fluid inlet to the suction chamber or as a fluid outlet from the pressure chamber. In each case, a very low fluid impedance for the inflow or outflow of fluid can be achieved.

[0029] According to a development of the present invention, at least one connecting channel is fluidically connected to the fluid chamber via an axial opening. In other words, the axial opening is fluidically located between the connecting channel and the fluid chamber. Accordingly, the fluid chamber is fluidically connected to the fluid connection portion via the axial opening and the corresponding connecting channel. Particularly preferably, of course, two connecting channels are fluidically connected to the fluid chamber via axial openings. This means that the first connecting channel is fluidically connected to the fluid chamber via the first axial opening. Additionally, the second connecting channel is fluidically connected to the same fluid chamber via the second axial opening. Thus, multiple flow paths exist between the fluid chamber and the fluid connection portion, wherein the first flow path is realized via the first axial opening and the first connecting channel, and the second flow path is realized via the second axial opening and the second connecting channel.

[0030] According to an extension of the present invention, the axial opening expands in the direction of the first gear and the second gear. Therefore, the flow cross section of the axial opening is not constant with respect to its corresponding extension, but changes. The flow cross section of the axial opening increases, i.e. increases, in the direction toward the gears. This expansion can, for example, be at least gradual or always continuous, thereby avoiding discontinuities in the flow cross section. However, the expansion can also occur suddenly, thereby constituting a dimensional jump in each axial opening. Preferably, the cross section of the axial opening is circular relative to its longitudinal extension. The expansion of the axial opening makes the inflow or outflow of the fluid particularly effective. It is particularly preferred that both axial openings are expanded. According to the present invention, the axial opening expands in the direction of the first gear and the second gear respectively. The embodiment of the expansion of the axial opening can serve as a supplement in various cases.

[0031] According to a further development of the present invention, one of the connecting channels is fluidically connected directly to the fluid connection, while the other connecting channel is fluidically connected to the fluid connection via a connecting channel that axially bridges the first and second gears. These connecting channels have, for example, the same flow cross-section. Preferably, at least one connecting channel opens into the axial opening (if present). Particularly preferably, both connecting channels open into a plurality of axial openings that may be present.

[0032] For example, the through-flow cross section of the axial opening on the side facing the gear and / or the corresponding axial opening can be smaller than the through-flow cross section on the side facing the gear and / or the corresponding connecting channel. This widens the through-flow cross section from the direction of the connecting channel toward the gear and / or the corresponding axial opening, and the through-flow cross section area is correspondingly increased.

[0033] The connecting channels can have the same longitudinal extension in the axial direction relative to their respective longitudinal center axes. One of the connecting channels is fluidically connected directly to the fluid connection, for example, directly connected to the fluid connection. The other of the connecting channels is fluidically connected to the fluid connection only indirectly via the connecting channel. In this case, the connecting channel completely overlaps the two gears in the axial direction.

[0034] In addition, the connecting channel can overlap at least one sealing washer or both sealing washer (if present). For example, the connecting channel can open into the connecting channel on the side of the first sealing washer facing away from the gear and into the fluid connection on the side of the other sealing washer facing away from the gear. For example, the connecting channel can open into the fluid connection axially, while the other connecting channel can open into the fluid connection radially.

[0035] The flow cross-sectional area of ​​the fluid connection is greater than the flow cross-sectional area of ​​the connecting channel. For example, the flow cross-sectional area of ​​the fluid connection is at least approximately 2.5 times, at least 3 times, at least 4 times, or at least 5 times greater than the flow cross-sectional area of ​​the connecting channel. Additionally or alternatively, the flow cross-sectional area of ​​the connecting channel is, for example, at least approximately 1.25 times, at least 1.5 times, at least 1.75 times, or at least 2.0 times greater than the flow cross-sectional area of ​​the connecting channel. This ensures highly efficient operation of the internal gear fluid machine.

[0036] According to a further development of the invention, the axial opening is surrounded by a seal, which bears sealingly against the sealing washer on the one hand and against the machine housing on the other hand. A pressure field is formed outside the area surrounded by the seal, which is fluidically connected to the pressure side of the internal gear fluid machine, so that the sealing washer is at least temporarily pressed toward the gear. The seal ensures a fluid-tight connection between the axial opening or the corresponding axial opening and the corresponding connecting channel.

[0037] A pressure field is applied at least temporarily to the pressurized fluid remote from the seal, i.e., outside the area surrounded by the seal and accessed by the axial opening and the connecting channel. For this purpose, the pressure field is fluidically connected to the pressure field of the internal gear fluid machine. The pressurized fluid presses the sealing gasket toward the gear, so that the fluid chamber is reliably sealed axially by the axial gasket. This is particularly preferably applicable to multiple sealing gaskets (if present). Thus, the axial openings can each be surrounded by a seal, which rests sealingly against the corresponding sealing gasket on the one hand and against the machine housing on the other hand. A pressure field is thus formed outside the area surrounded by the seal, which is fluidically connected to the pressure side of the internal gear fluid machine, so that the sealing gasket is at least temporarily pressed toward the gear.

[0038] According to a further development of the invention, the filling piece protrudes circumferentially into the axial opening and / or ends in an overlap with the axial opening, viewed circumferentially. Thus, the filling piece protrudes circumferentially into an imaginary extension of the axial opening. The filling piece engages at least in this imaginary extension, but may also completely pass through it circumferentially. Particularly preferably, the filling piece radially overlaps the axial opening, i.e., lies on an imaginary extension of the axial opening. This ensures a reliable and effective sealing of the fluid chambers from one another with the help of the filling piece. Thus, the filling piece protrudes circumferentially into the axial opening and / or ends in an overlap with the axial opening, viewed circumferentially.

[0039] According to a further development of the present invention, the filler piece tapers axially in the overlap with the axial opening, in particular, only on one or both sides. Particularly preferably, the tapering portion of the filler piece ends radially in the overlap with the axial opening. The tapering portion of the filler piece allows the filler piece to axially separate from the axial opening or at least one axial opening, i.e., to be continuous with the axial opening. In other words, the radial distance between the filler piece and the axial opening or at least one axial opening is increased. This facilitates the inflow or outflow of fluid.

[0040] Furthermore, the filler element's tapering is designed to effectively deflect the fluid in the circumferential direction, thereby enabling particularly efficient flow into or out of the corresponding fluid chamber. The filler element can be tapered only on one side, i.e., on the side facing the axial opening or one of the axial openings. However, it is particularly preferred that the filler element tapers on both sides, enabling efficient flow in or out through one or both axial openings. It is particularly preferred that the filler element be symmetrical in longitudinal cross-section, i.e., in the axial direction, so that the tapering is identical on both sides, albeit mirror-imaged.

[0041] According to a development of the invention, the filler piece's tapering ends in the overlap with one or more axial openings, viewed in the circumferential direction. The filler piece extends at least partially to the axial opening and preferably has a constant dimension, viewed in the radial direction, up to the tapering portion. For example, an imaginary extension of the filler piece up to the axial opening has an axial extension that corresponds to the distance between the sealing washers, so that the filler piece rests against the sealing washers away from the axial opening, in particular continuously in the circumferential direction. Only then, i.e., in the overlap with the axial opening, does the filler piece begin to taper, reducing its axial extension in the circumferential direction up to the free end of the filler piece. In other words, the tapering begins at the overlap with the axial opening and preferably extends to the free end of the filler piece. This ensures a reliable sealing effect of the filler piece.

[0042] According to a further development of the invention, the second gear is at least partially surrounded circumferentially by at least one bearing recess formed in the machine housing. This bearing recess only partially surrounds the second gear in the axial direction and is fluidically connected to a fluid connection, in particular via a flow resistor or a fluid line having a flow resistor. The bearing recess forms a hydrostatic support for the second gear. Thus, during operation of the internal gear fluid machine, the bearing recess is at least temporarily acted upon by pressurized fluid, causing the second gear to be radially displaced from the machine housing. This forms a fluid film between the second gear and the machine housing, thereby achieving particularly loss-free support of the second gear.

[0043] The support recess can completely surround the second gear in the circumferential direction, but preferably, it only partially surrounds the second gear in the circumferential direction. It is particularly preferred to provide two support recesses that are spaced apart from each other in the circumferential direction, i.e., the two support recesses are spaced apart from each other on both sides in the circumferential direction. In particular, the support recesses are symmetrical in cross-section about an imaginary plane that contains the rotation axis of the first gear and / or the rotation axis of the second gear. For example, the support recesses are preferably connected to different fluid connections using flow resistances. In other words, the first support recess is connected to the first fluid connection via a first flow resistance, and the second support recess is connected to the second fluid connection via a second flow resistance.

[0044] It should be understood here that each bearing recess is directly connected to the corresponding fluid connection via a corresponding flow resistance, and is only indirectly fluidically connected to each other fluid connection, in particular via a fluid space or one or more fluid chambers. Depending on the direction of rotation of the internal gear fluid machine, there is always one bearing recess that is fluidically connected to the pressure side and another bearing recess that is fluidically connected to the suction side of the internal gear fluid machine. This makes it possible to achieve a force balance within the internal gear fluid machine, resulting in very high efficiency. The flow resistance is especially provided in the fluid line through which the corresponding bearing recess is fluidically connected to the corresponding fluid connection. For example, the bearing recesses are respectively connected to the corresponding fluid connections via fluid lines, wherein a flow resistance is respectively provided in each fluid line. Within the scope of this specification, all embodiments concerning the bearing recess can preferably be applied to each of the multiple bearing recesses (if any).

[0045] The bearing recess only partially overlaps the second gear in the axial direction, so that the second gear completely overlaps the bearing recess in the axial direction. For example, the bearing recess is delimited on both sides in the axial direction by a bearing plate, which overlaps the bearing recess in the circumferential direction and has at least the same extension as the bearing recess. In the case of multiple bearing recesses, each bearing recess has such a bearing plate. The second gear rests sealingly on the bearing plate, in particular in a continuous overlap with the bearing recess in the circumferential direction, or the distance between the second gear and the bearing plate is smaller than the distance to the base of the bearing recess, which delimits the bearing recess in a direction away from the second gear, in particular radially outwardly. This reliably prevents an undesired flow of fluid from the bearing recess. For example, the second gear has a bearing play, i.e., a radial distance from the bearing plate, of a maximum of 0.25 mm, a maximum of 0.2 mm, a maximum of 0.15 mm, a maximum of 0.1 mm, a maximum of 0.075 mm, or a maximum of 0.05 mm. Preferably, the distance is a maximum of 0.1 mm or less.

[0046] The bearing recess is fluidically connected to the return flow portion (Rücklauf) of the internal gear fluid machine, and the fluid can be discharged through the return flow portion, especially in the direction of the suction side of the internal gear fluid machine. If there are multiple bearing recesses, the return flow portion or at least one return flow recess of the return flow portion is preferably arranged between the bearing recesses in the circumferential direction. In particular, the bearing recess is arranged at a distance from the return flow recess in the circumferential direction. The return flow recess is a recess formed in the machine housing and open in the direction of the gear. The return flow recess can have the same size as at least one bearing recess or multiple bearing recesses in the axial direction or exceed the bearing recess in the axial direction, especially only on one or both sides. One or more bearing recesses are each formed to be spaced apart from the return flow recess in the circumferential direction.

[0047] The return flow section is thus preferably designed to re-introduce the fluid therein into the internal gear fluid machine and convey it toward the pressure side of the internal gear fluid machine. As already mentioned, the support recess is circumferentially spaced apart from the return flow recess. However, the support recess can also be connected to the return flow section or the return flow recess at a specific radial position, in particular, connected to the return flow recess. The return flow section or the return flow recess can be arranged, for example, centrally relative to the filler element, viewed in the circumferential direction, thereby being centrally located between the pressure side and the suction side of the internal gear fluid machine, ultimately resulting in a symmetrical design.

[0048] In order to apply pressurized fluid to the support recess, it is connected to a fluid connection. Preferably, there is a flow resistance between the fluid connection and the support recess in terms of fluid technology, which reduces the pressure. The flow resistance is preferably present in the form of a cross-sectional reduction. Preferably, the flow cross-sectional area before and after the flow resistance or cross-sectional reduction is the same in terms of fluid technology. This means that the cross-sectional reduction is only present locally and, in particular, does not extend directly to the support recess. In other words, the flow cross-sectional area decreases in the area of ​​the cross-sectional reduction and then increases again, in particular also in the area of ​​the cross-sectional reduction. The ratio of the length to the width or diameter of the cross-sectional reduction area is, for example, a maximum of 0.25, a maximum of 20 or a maximum of 15. However, this ratio is preferably a maximum of 10 or a maximum of 5. Here, the width or diameter is understood to be the smallest dimension of the cross-sectional reduction over its extension.

[0049] The flow resistance can be used to reduce fluid losses from the bearing recess toward the return flow. The flow resistance is necessary because the pressure of the fluid commonly used on the pressure side of an internal gear fluid machine often exceeds that required for adequate support. Therefore, this pressure can be reduced without compromising the quality of the bearing. This pressure reduction in turn reduces the flow rate, so that the amount of fluid passing through the bearing recess toward the return flow or discharged into the return flow is very small.

[0050] For example, the flow resistance can be designed as a flow control plate, a flow control throttle valve or a flow control nozzle. The flow control plate can be understood as a jump-type cross-sectional reduction. The flow cross-sectional area decreases sharply at the beginning of the plate and widens sharply at the end of the plate, in particular until the same flow cross-sectional area as before the plate is reached. The ratio of the length to the width or diameter of the cross-sectional reduction portion in the flow direction of the plate is at most 2, at most 1.5 or at most 1. The description of the flow control plate also applies to the throttle valve, but with a difference, in that the ratio of the length to the width or diameter is greater for the throttle valve. In particular, this ratio is at least 2 or greater than 2. This ratio is, for example, at least 3, at least 4 or at least 5.

[0051] A nozzle is a cross-sectional reduction in which the flow cross-sectional area decreases continuously until it reaches a minimum. Downstream of the minimum flow cross-sectional area, the flow cross-sectional area widens again, either abruptly or continuously. In the latter case, the flow resistance includes a diffuser in addition to the nozzle. The nozzle and diffuser can, for example, be designed symmetrically or in mirror image, thus having the same longitudinal extension and the same flow cross-sectional area gradient. Using a nozzle and diffuser allows for an effective reduction in pressure or flow rate without incurring excessive losses.

[0052] The flow resistance is preferably designed such that the amount of fluid discharged from the support recess into the return flow per unit time corresponds to at most 50%, at most 40%, at most 30%, or at most 25% of the total amount of fluid flowing into the return flow per unit time. Such a flow resistance dimensioning is suitable in all cases to achieve adequate support of the second gear wheel in the machine housing. Of course, the amount of fluid per unit time can also be higher, for example, up to 75%, up to 70%, up to 65%, up to 60%, or up to 55% of the aforementioned amounts. However, smaller values ​​are preferred because, with these values, fluid loss can be significantly limited while ensuring adequate support quality.

[0053] The size of the flow resistance, in particular the minimum flow cross-section of the flow resistance, depends, for example, on the diameter of the second gear or the foot diameter of the internal toothing. This size can also be selected based on the radial and / or axial extension of the bearing recess. Additionally or alternatively, a dependency on the bearing play and / or the axial extension of the support plate can also be provided. For example, a dependency on the displacement volume of the internal gear fluid machine can be provided. In particular, the size ratio of the flow resistance, in particular the ratio of the minimum diameter of the flow resistance over its extension to the displacement volume, is at least 15 1 / m 2 Maximum 75 1 / m 2 , the minimum is 301 / m 2 Maximum 60 1 / m 2 Or a minimum of 301 / m 2 Maximum 45 1 / m 2 This gives a displacement volume of 8 cm 3The dimensions of the internal gear turbomachine are 0.12 mm to 0.6 mm. This value applies in particular to flow resistances designed as plates.

[0054] The bearing recess is particularly preferably connected fluidically to the two fluid connections, in particular via a flow resistance. This allows for a hydrostatic bearing to be implemented independently of the direction of rotation of the internal gear fluid machine and its operation as a pump or motor. The flow resistance is designed to be identical for both fluid connections. Alternatively, however, an asymmetrical design is also possible, in which different flow resistances are provided between the fluid connections and the bearing recess.

[0055] According to a further development of the present invention, the fluid connection is a first fluid connection among a plurality of fluid connections. The first fluid chamber is fluidically connected to the fluid connection serving as the first fluid connection via a connecting channel serving as the first connecting channel. A second connecting channel is formed in the housing wall, and the second fluid chamber is fluidically connected to the second fluid connection via the second connecting channel. Thus, the internal gear fluid machine comprises a total of a plurality of fluid connections, a plurality of first connecting channels, and a plurality of second connecting channels. Here, the already described fluid connection is formed as the first fluid connection, and the already described connecting channel is formed as the first connecting channel.

[0056] In addition to the first fluid connection, a second fluid connection is now present, and in addition to the first connecting channel, a second connecting channel is present in the machine housing. The second fluid chamber is fluidically connected to the second fluid connection via the second connecting channel, preferably permanently. The other embodiments regarding the first connecting channel within the scope of this description also apply analogously to the second connecting channel.

[0057] Particularly preferably, the filler element extends circumferentially from the first connecting channel to the second connecting channel, i.e., it intersects with an imaginary extension of the first connecting channel and an imaginary extension of the second connecting channel. Furthermore, it is particularly preferred that the described tapering portion is provided and implemented on the side of the filler element facing the first connecting channel and the side facing the second connecting channel. The described embodiment particularly enables direction-independent operation of the internal gear fluid machine.

[0058] Additionally or alternatively, the embodiments for connecting the channels also apply to one or more axial openings. Thus, the fluid connection is the first fluid connection among a plurality of fluid connections, the first fluid chamber being fluidically connected to the fluid connection serving as the first fluid connection via the axial opening serving as the first axial opening, and a second axial opening being formed in the sealing gasket, the second fluid chamber being fluidically connected to the second fluid connection via the second axial opening. Of course, a plurality of sealing gaskets having a corresponding plurality of axial openings, wherein these axial openings are formed as first axial openings, is particularly preferred. In such a design, a second axial opening is formed in each sealing gasket, wherein the second fluid chamber is fluidically connected to the second fluid connection via the second axial opening.

[0059] According to a further development of the present invention, the filler element is designed symmetrically in the circumferential direction, making the internal gear fluid machine reversible. This means that the filler element is divided into a plurality of segments in the circumferential direction. Particularly preferably, the filler element has a total of four segments, since the filler element is divided into segments both radially and circumferentially. This allows radial compensation of the internal gear fluid machine independent of its direction of rotation. Such an internal gear fluid machine may also be referred to as a four-quadrant internal gear fluid machine or a reversible internal gear fluid machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The present invention will be described below with reference to the embodiments shown in the accompanying drawings without limiting the present invention.

[0061] Figure 1 A cross-sectional view schematically illustrating an internal gear fluid machine;

[0062] Figure 2 A longitudinal section of an internal gear fluid machine is schematically shown;

[0063] Figure 3 Another longitudinal sectional view schematically showing an internal gear fluid machine;

[0064] Figure 4 A first detailed view showing a filler of an internal gear fluid machine; and

[0065] Figure 5 A further schematic detailed view of a filling piece is shown. DETAILED DESCRIPTION

[0066] Figure 1 A schematic cross-sectional view of an internal gear fluid machine 1 is shown. The internal gear fluid machine 1 includes a machine housing 2 in which a first gear 3 and a second gear 4 are rotatably supported. The first gear 3 can also be referred to as a pinion gear, and the second gear 4 can also be referred to as a ring gear. The first gear 3 is rotatably supported in the machine housing 2 about a first rotational axis 5, and the second gear 4 about a second rotational axis 6. It can be seen that the first rotational axis 5 and the second rotational axis 6 are arranged parallel to each other and spaced apart, so that the first gear 3 and the second gear 4 have different rotational axes. The first gear 3 has an external toothing 7, and the second gear 4 has an internal toothing 8. The external toothing 7 and the internal toothing 8 mesh with each other in a joining region 9, i.e., they engage with each other.

[0067] The first gear 3 and the second gear 4 jointly define a fluid space 10. The first gear 3 radially delimits the fluid space 10 inward, while the second gear 4 radially delimits the fluid space 10 outward. The fluid space 10 is divided circumferentially into a first fluid chamber 12 and a second fluid chamber 13 by the meshing of the first gear 3 and the second gear 4 and by a filler 11. Depending on the direction of rotation of the internal gear fluid machine 1, one of the fluid chambers 12 and 13 functions as a suction chamber, while the other functions as a pressure chamber.

[0068] In this embodiment, the filler piece 11 is symmetrically designed to enable reversible operation of the internal gear turbomachine 1. Thus, the internal gear turbomachine 1 can be operated in both directions. Additionally or alternatively, the filler piece 11 can be constructed as a multi-piece structure having multiple segments 14 and 15 or 16 and 17. The segments 14 and 15 or 16 and 17 are divided radially. Accordingly, the first segment 14 or 16 abuts the first gear 3, and the second segment 15 or 17 abuts the second gear 4.

[0069] Between the segments 14 and 15 or 16 and 17 there is a gap 18 or 19, to which a pressurized fluid can be applied. This application of fluid causes the segments 14 and 15 or 16 and 17 to be pressed in the direction of the corresponding gear 3 or 4. This results in radial compensation of the internal gear turbomachine 1.

[0070] It can also be seen that the second gear 4 is surrounded at least partially, in particular only partially, in the circumferential direction by one or more bearing recesses 20. The bearing recesses 20 are fluidically connected to fluid connections 21 and 22 (not shown) of the internal gear turbomachine 1, preferably via flow resistors 23. The fluid connection between the respective bearing recess 20 and the fluid connections 21 and 22 can be achieved via corresponding connecting channels 24 and 25. The bearing recesses 20 are designed so that pressurized fluid, for example from the fluid connections 21 and 22, can be applied at least temporarily, so that they form a hydrostatic bearing for the second gear 4.

[0071] It is also possible to fluidically connect the bearing recess 20 to only one of the fluid connections 21 and 22, which corresponds to the pressure side of the internal gear turbomachine 1. This is particularly the case when the internal gear turbomachine 1 is not reversible or operates only in a preferred direction of rotation. However, if the internal gear turbomachine 1 is designed for reversible operation and operates in a time-alternating direction of rotation, the bearing recess 20 is preferably fluidically connected to both fluid connections 21 and 22, i.e., one bearing recess 20 is connected to the fluid connection 21 and the other bearing recess 20 is connected to the fluid connection 22. This ensures that the pressure on the pressure side of the internal gear turbomachine 1 is always applied to one bearing recess 20, while the lower pressure on the suction side is applied to the other bearing recess 20.

[0072] Figure 2 A longitudinal section through an internal gear turbomachine 1 is schematically shown. Gears 3 and 4 are axially supported in the machine housing 3 by means of (purely optional) sealing washers 26. Sealing washers 26 are disposed on opposite sides of gears 3 and 4 and rest sealingly against them during operation of the internal gear turbomachine 1. A first axial opening 27 and a second axial opening 28 are formed in sealing washers 26. Axial openings 27 and 28 completely penetrate the respective sealing washers 26 in the axial direction.

[0073] It can be seen that the axial openings 27 and 28 widen in the direction of the gears 2 and 4, respectively. For example, when viewed in cross section, the axial openings 27 and 28 on the side facing the gears 3 and 4 are aligned radially inwardly with the foot circle of the external toothing 7 and / or radially outwardly with the foot circle of the internal toothing 8. Only the first case is shown here. At least when viewed in cross section, the axial openings 27 and 28 are located between the foot circles of the external toothing 7 and the foot circles of the internal toothing 8 and therefore do not protrude radially. This ensures high efficiency of the internal gear fluid machine 1.

[0074] Axial openings 27 are provided on both sides of the first fluid chamber 12, and second axial openings 28 are provided on both sides of the second fluid chamber 13. Thus, the first fluid chamber 12 is fluidically connected to the first fluid connection 21 via the first axial openings 27. Similarly, the second fluid chamber 13 is fluidically connected to the second fluid connection 22 via the second axial openings 28. For this purpose, connecting channels 29 and 30 are formed in the machine housing 2. The first axial opening 27 is connected to the corresponding fluid connection 21 or 22 via the connecting channel 29, and the second axial opening 28 is connected to the corresponding fluid connection 21 or 22 via the second connecting channel 30. The sealing gasket 26 and the axial openings 27 formed therein can be omitted. In this case, a direct fluid connection exists between the connecting channels 29 and 30 and the fluid chambers 12 and 13. Of course, only one sealing gasket 26 can also be used.

[0075] In the embodiment shown here, one connecting channel 29 is directly connected to the corresponding fluid connection 21 or 22, while the other of the connecting channels 29 and 30 is connected to the corresponding fluid connection 22 via the corresponding connecting channel 24 or 25. Here, the connecting channels 24 and 25 completely overlap the gears 3 and 4 and the sealing washer 26 in the axial direction.

[0076] As shown here, the first connecting channel 29 can be connected axially and the connecting channels 24 and 25 can be connected radially to the corresponding fluid connection 21 or 22. The axial openings 27 and 28 are each surrounded by a seal 31 or 32, which ensures a fluid-tight seal between the corresponding axial opening 27 or 28 and the corresponding connecting channel 29 or 30.

[0077] It can be seen that the overall dimensions of the axial washer 26 in the axial direction correspond at least to the dimensions of the gears 3 and 4 in the same direction. This allows for very reliable support of the gears 3 and 4 in the machine housing 2. In particular, tilting of the axial washer 26 and the resulting uneven sealing of the fluid chambers 12 and 13 are reliably prevented.

[0078] Figure 3 Another longitudinal section through the internal gear turbomachine 1 is schematically shown. It can be seen that the filler piece 11 extends circumferentially to the axial opening 28 and ends in the region of the axial opening 28. A similar configuration naturally applies to the first axial opening 27. The filler piece 11 has a tapered portion 34, which tapers axially, in the embodiment shown here on both sides. The tapered portion 34 is formed on the filler piece 11 at the end face in the circumferential direction.

[0079] The tapered portion 34 ends in the overlap with the axial opening 28 when viewed in the circumferential direction, so that the axial dimension of the filling piece 11 in the overlap with the axial opening 28 corresponds to the distance between the two sealing washers 26. The filling piece 11 begins to taper toward its free end only in the overlap with the axial opening 28. The tapered portion 34 optimizes the flow guidance, allowing the fluid to flow into or out of the corresponding fluid chamber 12 or 13 without hindrance.

[0080] A pressure field is preferably formed away from the seal 32, which serves to apply a pressurized fluid to the sealing gasket 26 with a force in the direction of the gears 3 and 4. The fluid is supplied to the pressure field, for example, from one or both of the fluid connections 21 and 22. For this purpose, corresponding fluid connections can be implemented. The described embodiment ensures that the fluid chambers 12 and 13 are reliably sealed in the axial direction by the sealing gasket 26.

[0081] Figure 4 The first detailed illustration of the filling piece of the internal gear fluid machine 1 is shown. The filling piece 11 is designed to be symmetrical in the circumferential direction and therefore has at least an axis of symmetry 35 and is mirror-symmetrical about the axis of symmetry 35. A tapered portion 34 is formed on the filling piece 11 at the end side in the axial direction. The extension of the filling piece 11 in the circumferential direction is at least 180°, preferably greater than 180°, in particular at least 190°, at least 200°, at least 210° or at least 220°. In the embodiment shown here, the extension of the filling piece 11 in the circumferential direction is at least 225°. The embodiment of the filling piece 11 described enables reversible operation of the internal gear fluid machine 1, that is, operation in any direction of rotation. In addition, a more reliable sealing between the fluid chambers 12 and 13 in the circumferential direction is achieved.

[0082] Figure 5Another schematic detailed view of the filling piece 11 is shown, in which the tapering 34 on both ends is again shown. The tapering 34 allows a particularly efficient flow of fluid into and out of the fluid chambers 12 and 13. Preferably, the filling piece has a constant dimension away from the tapering 34 or the tapering 34 in the axial direction.

[0083] In addition Figure 1 and Figure 4 1 shows a return flow 36, through which fluid, particularly leaking fluid, can be discharged from the internal gear turbomachine 1 and / or flow back into the internal gear turbomachine 1 or the corresponding suction chamber. The return flow 36 is arranged approximately in the center, preferably exactly in the center, relative to the filler element 11, as viewed in the circumferential direction. The return flow 36 is particularly preferably symmetrical about an imaginary plane that contains the first rotational axis 5 and the second rotational axis 6.

[0084] The return flow section 36 has a return flow recess 37 that extends through the inner circumference of the machine housing 2 facing the second gear 3 , so that the return flow recess 37 is open in the direction of the gears 3 and 4 . Furthermore, the return flow section 36 has a return flow pocket 38 that is preferably fluidically connected to the return flow pocket 37 . When the return flow pocket 37 overlaps the gears 3 and 4 axially, the return flow pocket 38 is located on both sides of the gears 3 and 4 axially. In particular, the return flow pocket 38 is formed on the side of the sealing disk 26 in the machine housing 2 that faces away from the gears 3 and 4 .

[0085] The fluid can be discharged and preferably re-introduced into the corresponding suction chamber via the return flow portion 36, i.e., the return flow recess 37 and the return flow pocket 38. For example, the support recess 20 is connected to the return flow recess 37. The support plate (Lagerstege) that axially delimits the support recess 20 can also be used to axially delimit the return flow recess 37. However, the support recess 20 is preferably arranged spaced apart from the return flow recess 37 in the circumferential direction. Preferably, the plurality of support recesses are symmetrically designed with respect to the return flow recess 37, in particular, at the same distance from the return flow recess 37.

[0086] In order to limit the amount of leaking fluid, flow resistors 23 are provided. The flow resistors 23 are preferably of identical construction and have, for example, a minimum diameter in their extension which is at least 15 1 / m with respect to the displacement volume of the internal gear fluid machine 1. 2 Maximum 751 / m 2This allows for effective support of the second gear 4 in the machine housing 2 while significantly reducing the amount of fluid leakage. One of the flow resistors 23 is located fluidically between the support recess 20 and the pressure side, while the other flow resistor is located between the other support recess 20 and the suction side. The fluid connection between the support recesses 20 is preferably established only through unavoidable leakage and / or through the internal gear turbomachine 1 itself, i.e., through the fluid space 10 or at least one or both fluid chambers 12 and 13.

[0087] The described embodiment of the internal gear turbomachine 1 enables very efficient fluid guidance and high throughput. Furthermore, the symmetrical design of the filler element 11 enables reversible operation. The multi-part design of the filler element 11 creates a four-segment internal gear turbomachine that can ensure effective radial sealing of the fluid chambers 12 and 13 from one another using the filler element 11 in any direction of rotation.

Claims

1. An internal gear fluid machinery (1) having - a first gear wheel (3) having an external toothing (7) and being supported rotatably about a first rotational axis (5), and a second gear wheel (4) having an internal toothing (8) partially meshing with the external toothing (7) in a joining region (9), the second gear wheel (4) being supported rotatably about a second rotational axis (6) different from the first rotational axis (5), wherein: a filling piece (11) arranged between the first gear (3) and the second gear (4) remote from the joining region (9), the filling piece (11) being in contact with the outer toothing (7) on the one hand and the inner toothing (8) on the other hand, so as to divide the fluid space (10) existing between the first gear (3) and the second gear (4) into a first fluid chamber (12) and a second fluid chamber (13), and, - a housing wall of the machine housing (2) of the internal gear fluid machine (1) arranged on both sides of the first gear (3) and the second gear (4) in the axial direction relative to the first rotating shaft (5), It is characterized by having - first connecting channels (29) respectively constructed in the two housing walls, the first fluid chamber (12) being fluidically connected to the first fluid connection (21) of the internal gear fluid machine (1) via the two first connecting channels (29), and second connecting channels (30) respectively constructed in the two housing walls, the second fluid chamber (13) being fluidically connected to the second fluid connection (22) of the internal gear fluid machine (1) via the two second connecting channels (30), and - At least one sealing washer (26) is arranged next to the first gear (3) and the second gear (4) in the axial direction about the first rotating shaft (5), and the sealing washer (26) is sealed against the first gear (3) and the second gear (4) during the operation of the internal gear fluid machinery (1), wherein a first axial opening (27) and a second axial opening (28) are formed in the sealing washer (26), and the first fluid chamber (12) is fluidically connected to the first fluid connection (21) through the first axial opening (27), and the second fluid chamber (13) is fluidically connected to the second fluid connection (22) through the second axial opening (28).

2. The internal gear fluid machinery according to claim 1, characterized in that: At least one first connecting channel (29) is fluidically connected to the first fluid chamber (12) via the first axial opening (27), or at least one second connecting channel (30) is fluidically connected to the second fluid chamber (13) via the second axial opening (28).

3. The internal gear fluid machinery according to claim 1, characterized in that: The first axial opening (27) or the second axial opening (28) expands in the direction of the first gear (3) and the second gear (4).

4. The internal gear fluid machinery according to any one of claims 1 to 3, characterized in that: One of the two first connecting channels (29) is fluidically connected directly to the first fluid connection (21), while the other of the two first connecting channels (29) is fluidically connected to the first fluid connection (21) via a first connecting channel (24) axially bridging the first gear (3) and the second gear (4); and / or one of the two second connecting channels (30) is fluidically connected directly to the second fluid connection (22), while the other of the two second connecting channels (30) is fluidically connected to the second fluid connection (22) via a second connecting channel (25) axially bridging the first gear (3) and the second gear (4).

5. The internal gear fluid machinery according to any one of claims 1 to 3, characterized in that: The first axial opening (27) is surrounded by a first seal (31), which, on the one hand, bears sealingly against the sealing washer (26) and, on the other hand, bears sealingly against the machine housing (2), wherein a pressure field is formed outside the area surrounded by the first seal (31) and is fluidically connected to the pressure side of the internal gear fluid machine (1), so that the sealing washer (26) is at least temporarily pressed in the direction of the gears (3, 4), or the second axial opening (28) is surrounded by a second seal (32), which, on the one hand, bears sealingly against the sealing washer (26) and, on the other hand, bears sealingly against the machine housing (2), wherein a pressure field is formed outside the area surrounded by the second seal (32) and is fluidically connected to the pressure side of the internal gear fluid machine (1), so that the sealing washer (26) is at least temporarily pressed in the direction of the gears (3, 4).

6. The internal gear fluid machinery according to any one of claims 1 to 3, characterized in that: The filling piece (11) protrudes circumferentially into the first axial opening (27) or the second axial opening (28) and / or ends in overlap with the first axial opening (27) or the second axial opening (28) as viewed in the circumferential direction.

7. The internal gear fluid machinery according to any one of claims 1 to 3, characterized in that: The filling piece (11) tapers in the axial direction when overlapping with the first axial opening (27) or the second axial opening (28).

8. The internal gear fluid machinery according to any one of claims 1 to 3, characterized in that: The tapered portion (34) of the filling piece (11) ends in an overlap with the first axial opening (27) or the second axial opening (28) as viewed in the circumferential direction.

9. The internal gear fluid machinery according to any one of claims 1 to 3, characterized in that: The second gear wheel (4) is at least partially surrounded in the circumferential direction by at least one bearing recess (20) formed in the machine housing (2), which only partially surrounds the second gear wheel (4) in the axial direction and is fluidically connected to the first fluid connection (21) and / or the second fluid connection (22).

10. The internal gear fluid machinery according to any one of claims 1 to 3, characterized in that: The filling piece (11) is symmetrically configured in the circumferential direction, so that the internal gear fluid machine (1) is reversible.

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