DE102022119807A1 - Gearbox, gas turbine engine with a gearbox and method for determining a filter fineness of a filter device of a gearbox - Google Patents

Abstract

A transmission (30) is proposed with at least one planet gear (32), which is rotatably mounted on a rotatable planet carrier (34) via a bearing unit (41A). The bearing unit (41A) can be supplied with oil via an oil supply (45, 46). The oil supply (45, 46) is designed upstream of the bearing unit (41A) with at least one filter device (62, 74) for the oil with which the bearing unit (41A) can be supplied. A filter fineness (dFilter62, dFilter74) of the filter device (62, 74) is dependent on the maximum drive power (P) applied to the gearbox (30) and the maximum angular velocity (ωB) of the planet carrier (34) and/or the gear ratio of the gearbox ( 30) set. Furthermore, a gas turbine engine (10) with such a gearbox (30) and a method for determining the filter fineness (dFilter62, dFilter74) of the filter device (62, 74) are proposed.

Description

The present disclosure relates to a transmission with at least one planetary gear and a gas turbine engine with such a transmission. Furthermore, the present disclosure relates to a method for determining a filter fineness of a filter device of a transmission with at least one planetary gear.

Gearboxes or planetary gearboxes are designed with bearing units, such as rolling and/or plain bearings, in order to rotatably mount planetary gears on planetary pins of planetary carriers. Along with rolling bearings, plain bearings are the most commonly used type of bearing in mechanical and equipment engineering. In plain bearings, the two parts that move relative to one another are in direct contact. They slide against each other against the resistance caused by sliding friction. This can be kept low by choosing a low-friction material pairing, by lubrication or by creating a lubricating film that separates the two contact surfaces from each other. When the two parts touch, which is the case with most plain bearings used, wear occurs in the contact surfaces, which limits the life of a plain bearing. Creating the separating lubricating film with full lubrication requires additional effort. The sliding resistance causes a portion of the kinetic energy to be converted into thermal energy, which flows into the two bearing parts and must be dissipated if necessary.

In gearboxes for turbine engines, plain bearings are often used, between whose partners the sliding resistance results from fluid friction. The lubricating film desired in the bearing gap must be put under pressure so that it can separate the contact surfaces against the bearing force. An oil pump is used for hydrostatic plain bearings. In contrast, with so-called hydrodynamic plain bearings, the oil pressure in the lubricating film is generated by the two contact surfaces that move towards each other.

In addition, when it comes to gearboxes for gas turbine engines in aircraft, it must be taken into account that high demands are placed on plain bearings and rolling bearings due to the limited amount of oil available and the high operating temperatures. In addition, the overall weight of a gas turbine engine should be as low as possible. Basically, the aim is to ensure that the probability of failure of plain and rolling bearings is as low as possible.

For this purpose, plain and/or rolling bearings, which are provided between a planetary gear and a planetary pin of a rotatable planetary carrier, can be supplied with oil via two separate oil supply lines. Due to the redundant oil supply to such a plain and/or rolling bearing, the plain and/or rolling bearing can still be supplied with oil via the other oil feed even if one of the oil feeds fails.

In order to prevent the service life of a plain and/or rolling bearing from being impaired by dirt particles entering the bearing gap and the resulting high probability of failure, the oil supply lines have filter devices or oil filters. In the case of so-called closed oil feeds, which are designed to be pressure-tight between a sliding and/or rolling bearing and a pressure side of an oil pump, only a small amount of dirt is introduced into the feed area of the oil between the oil pump and a bearing compared to so-called open oil feeds. Therefore, an oil filter of a closed oil supply can be arranged in the area of the gas turbine engine, which is easily accessible during an inspection or maintenance of a gas turbine engine. It is then possible to check the functionality of the oil filter and replace any oil filter that may be dirty.

In contrast, dirt can penetrate more easily into an open oil supply, into which oil is introduced essentially without pressure through an opening in the open oil supply. Therefore, the oil filter must be arranged in an area of the open oil supply downstream of the opening, which is therefore difficult to access. Inspection and replacement of the oil filter are then only possible with considerable assembly effort, which results in high maintenance costs or increases the probability of failure because the oil filters of open oil feeds cannot be maintained and replaced accordingly.

In addition, known procedures for designing the filter fineness of oil filters rely on complex and lengthy series of tests, which increases the manufacturing costs of a transmission to an undesirable extent. The filter fineness corresponds to the ability of an oil filter to filter out particles above a certain particle size from an oil volume flow.

The present disclosure is therefore based on the object of providing a transmission and a gas turbine engine with a transmission, which are each characterized by a low probability of failure and can each be produced more cost-effectively compared to known solutions. Furthermore, the present disclosure is based on the task of providing a method for determining a filter fineness of a filter To provide direction of a transmission with at least one planet gear.

This task is achieved with a transmission, with a gas turbine engine and with a method with the features of patent claims 1, 20 and 21, respectively. Advantageous further developments are the subject of the subclaims and the following description.

A transmission, in particular a planetary transmission of a gas turbine engine, is proposed with at least one planet gear, which is rotatably mounted on a rotatable planet carrier via a bearing unit. The planet carrier can be connected in a rotationally fixed manner to a planet bolt on which the planet gear is rotatably mounted. The bearing unit can be supplied with oil via an oil supply. The oil supply is designed upstream of the storage unit with at least one filter device or an oil filter for the oil with which the storage unit can be supplied.

The filter fineness of the filter device is determined depending on the maximum drive power applied to the transmission and the maximum angular velocity of the planet carrier and/or the transmission ratio of the transmission.

In the present case, the term filter fineness of the filter device is understood to mean the average diameter of the openings of the filter device through which the medium or oil flows, from which the particles are to be separated on the surface of the filter or in the filter. The average diameter of the openings or the flow openings of the filter device also influences the so-called degree of filtration of the filter device.

The flow openings of a filter device can each be designed as circular, oval and/or triangular or polygonal recesses in the filter material. Depending on the selected filter material, the flow openings can be introduced into the filter material using suitable mechanical or thermal processing methods or can be created during the production of the filter material, which is designed, for example, as a woven or knitted fabric, with the average diameter of the flow openings in so-called fabric or knitted filters corresponds to an average mesh size of the filter fabric or the filter knitted fabric.

The present disclosure is based on the knowledge that a minimum bearing gap dimension is established in the area of the bearing unit depending on the maximum drive power applied to the transmission and the maximum angular velocity of the planet carrier and/or the gear ratio of the transmission.

As is known, the minimum bearing gap varies in the circumferential direction of the bearing unit depending on the resulting bearing load. When the planet carrier rotates at the same time, the bearing load of a bearing unit of a planetary gear essentially depends on the torque to be transmitted via the planetary gear and the centrifugal force acting on the planetary gear during operation.

The minimum bearing gap dimension of a bearing unit designed as a plain bearing corresponds to the minimum bearing gap height. If the bearing unit is designed as a rolling bearing, then the minimum bearing gap dimension is, for example, in the area between the rolling bodies and a cage in front of or between the rolling body running surface and a cage in which the rolling bodies are guided between the bearing shells at a corresponding distance in the circumferential direction of the bearing unit.

Regardless of the type of bearing used, the minimum bearing gap dimension represents the essential design criterion for the filter fineness of a filter device for the oil that is supplied to the bearing unit. If the bearing unit is supplied with oil containing dirt particles whose particle diameters have at least approximately values that correspond to the value of the minimum bearing gap, there is a great risk that such particles will block the flow path of the oil in the bearing unit. This can reduce the cooling and lubrication of the bearing unit to such an extent that the bearing unit is thermally and mechanically overloaded, which undesirably impairs its service life. Such obstruction can also lead to progressive wear. The wear, triggered by dirt particles that are too large for the minimum bearing gap, creates additional particles that increase the wear.

Since the filter fineness of the filter device of the transmission is determined according to the present disclosure depending on the maximum drive power applied to the transmission and the maximum angular velocity of the planet carrier and / or the gear ratio of the transmission, the transmission has lower manufacturing and maintenance costs compared to known transmissions and characterized by a lower probability of failure. This is the case because the filter fineness of the filter device depends on the known operating variables, namely the maximum drive power applied to the transmission and the maximum angular velocity of the planet carrier and / or the transmission ratio and This means that it is ultimately determined with high precision depending on the minimum bearing gap dimension and cannot, as was previously the case, be determined through complex tests that cause high manufacturing costs. By precisely determining the filter fineness, thermal and mechanical overloads on the bearing unit are avoided and a low probability of failure is achieved.

In an advantageous and cost-effective development of the transmission according to the present disclosure, which is characterized by a low probability of failure, the filter fineness d _filter of the filter device is according to the formulaic relationship $$d_{filter}=x\cdot \sqrt[-2]{\frac{P^2}{{\omega }_b^2}+{\omega }_b^4}$$

depending on the maximum drive power P applied to the gearbox and the maximum angular velocity ω _B of the planet carrier. Here, x is the ratio between the bearing load that occurs during operation with the maximum drive power P applied to the transmission and with the maximum angular velocity ω _B of the planet carrier in the area of the bearing unit, and the filter fineness of the filter device.

According to a further aspect of the present disclosure, a transmission with at least one planet gear is proposed, which is rotatably mounted on a rotatable planet carrier via a bearing unit. The bearing unit can be supplied with oil via an oil supply. The oil supply is designed upstream of the storage unit with at least one filter device for the oil with which the storage unit can be supplied.

If the filter fineness of the filter device has values between 10µm and 400µm, the transmission can be operated with the desired low probability of failure and with low maintenance costs.

In further developments of the transmission according to the present disclosure, which can also be operated with a desired low probability of failure and with low maintenance costs, the filter fineness of the filter device has values between 25 µm and 250 µm, preferably between 50 µm and 150 µm.

In further embodiments of the transmission according to the present disclosure that are inexpensive to produce and can be operated with low maintenance costs, the filter fineness can be determined depending on a maximum drive power applied to the transmission, which is in a range from 40 MW to 100 MW, preferably from 50 MW to 60 MW.

In addition, there is also the possibility that the filter fineness is determined depending on a maximum angular velocity of the planet carrier, which is in a range from 105 1/s to 210 1/s, preferably in a range from 145 1/s to 190 1/s .

The filter fineness can be determined depending on a gear ratio of the transmission, which lies in a value range of 3 to 5.

Furthermore, the transmission can have 3 to 7 planetary gears, preferably 5 planetary gears.

The oil supply can have a filter device provided in the area of the gas turbine engine or on the housing side, which is preferably designed as a paper filter.

A surface through which oil can flow in the area of the filter device can have values in a range from 1,000 mm ² to 10,000 mm ² , preferably from 2,500 mm ² to 7,500 mm ² .

The filter fineness of the filter device can be determined depending on a kinematic viscosity of the oil that is supplied to the storage unit. The viscosity of the oil can be from 3 to 10 cStokes at an oil temperature of 100 °C.

The transmission can have a closed oil supply and/or an open oil supply.

The open oil supply can include a channel extending in the circumferential direction and connected to the planet carrier. The channel can be designed to be open radially inwards in the area of a feed-side opening of the open oil supply, with the filter device or the oil filter being provided in the channel. In this embodiment of the planetary gear according to the present disclosure, the oil can be sprayed or injected radially outwards into the channel in a simple manner starting from an oil supply unit. When the planet carrier rotates, the introduced oil is guided into the channel by the centrifugal force acting in the direction of the oil filter and through the oil filter. Dirt particles carried in the oil are filtered out in the area of the oil filter and collected in a volume limited by the channel and the oil filter upstream of the oil filter.

Downstream of the oil filter, the oil is directed from a radially outer channel region of the channel of the bearing unit if the centrifugal force acting on the oil is sufficiently large for this.

The oil filter can be firmly connected to boundary walls of the channel in a filter section that faces the radially outer channel region. In addition, the oil filter can comprise a further filter section which extends radially inwards from the filter section into the interior of the channel and through which the oil in the channel can flow. The further filter section can be designed to run at least in regions at a distance from at least one of the boundary walls of the gutter in the interior of the gutter. Then dirt particles filtered out by the oil filter can be guided radially outwards in the channel in the direction of the filter section to the desired extent and collected and retained there, without clogging the further filter section and hindering or completely preventing the oil from flowing through the further filter section to an undesirable extent prevent.

In a structurally simple embodiment of the planetary gear according to the present disclosure, the filter section can be designed as a cylindrical partition wall which extends in the groove in the circumferential direction and in the axial direction of the groove and is connected to the lateral boundary walls of the groove.

The partition can be designed with a plurality of through openings spaced apart in the circumferential direction of the channel, in the area of which a further filter section is provided. The largest possible collecting volume for dirt particles is then provided upstream of the storage unit and upstream of the oil filter, which prevents the oil filter from clogging with little effort.

The at least one further filter section can be designed as a hollow cylindrical body made of filter material.

In addition, there is also the possibility that the further filter section is designed to be conical. The filter section can be connected to the partition in the area of its base area and can extend radially inwards away from the partition in the direction of the open area of the channel.

Both the hollow cylindrical and the conical design of the further filter section promote the removal of dirt particles filtered out to the desired extent radially outwards along the further filter section using the centrifugal force and prevent the filter from clogging to the desired extent.

The radially outer channel area can be connected to a line which runs at least in some areas in the axial direction in the planetary bolt and which is connected to a further line opening into the bearing unit. The oil can then be fed to the bearing unit with little production effort.

In a further embodiment of the planetary gear according to the present disclosure, a further line of a closed oil supply opens into the bearing unit. Oil can be fed via the line from an additional line running in the planetary bolt to the closed oil supply of the bearing unit. Thanks to the planetary gear, the bearing unit can then be supplied with oil via a redundant oil supply, which means that the probability of failure of the bearing unit and thus of the planetary gear is low, even if the oil supply fails via the open oil supply.

In a further embodiment of the planetary gear according to the present disclosure, the additional line of the closed oil supply is fluidly connected to an oil line running in the planet carrier. The connection area between the additional line and the oil line is sealed from the environment of the planetary gear, which means that oil can be introduced under pressure into the oil supply pocket and thus into the bearing unit when the planet carrier is stationary or only rotating slowly.

In further embodiments of the transmission according to the present disclosure, the filter fineness of the filter device can be adapted to the respective application by a single-layer or multi-layer design of the filter device.

The filter fineness can, for example, be varied in a simple manner with a multi-layer design of the filter device by arranging the individual filter layers one on top of the other in such a way that the flow openings of the individual filter layers overlap to a greater or lesser extent depending on the respective application and thereby the flow cross section of the filter device that can be flowed through varies overall.

This can be achieved with little effort, since in a multi-layer design the filter device has several filter layers arranged in the direction of flow of the oil through the filter device, such as perforated plates, filter fabrics, filter fabrics, fil backing paper and the like, with defined hole diameters. It is then possible to arrange the openings or holes of the individual filter layers offset from one another in the flow direction so that the area of the filter device through which flow can flow can be adjusted independently of the technical feasibility of the diameter of the flow openings in the individual layers.

If the filter device is fixed on the housing side, the filter device can be designed, for example, as a cost-effective paper filter or as a non-metallic fabric or knitted fabric filter.

If, on the other hand, the filter device is provided in an area of the oil supply that is provided within the rotatable planet carrier, there is a simple possibility of designing the filter device as a metal filter, in particular as a metallic hole filter, as a metallic fabric or knitted fabric filter or as a metallic mesh filter. Metallic filters have a higher mechanical load capacity than paper filters or non-metallic filter devices.

The filter device can be designed with at least one conical filter section, wherein the filter section can extend with its outside against the flow direction of the oil in the closed or in the open oil supply or in the flow direction of the oil in the closed or in the open oil supply. If the filter device or the oil filter extends at least in some areas against the flow direction of the oil, it is ensured in a structurally simple manner that dirt particles filtered out of the oil by the filter device do not remain on the outside of the oil filter, which are in the flow path against the flow direction of the oil extends. Then the dirt particles are at least partially guided by the oil flow, for example in the open oil supply on the outside of the filter device, and settle in an area of the oil filter that faces away from the opening of the open oil supply. This prevents the oil filter from becoming blocked or clogged by dirt particles filtered out of the oil for as long as possible. This promotes an oil supply to the bearing unit via the particularly open oil supply and reduces the probability of failure compared to known bearing units.

In other words, the dirt particles filtered out of the oil in the area of the oil filter are guided by the centrifugal force along the outside of the oil filter into a volume within the oil supply, which is in the direction of the centrifugal force acting radially outwards and thus lies radially further out than large areas of the oil filter . In comparison to existing gearboxes, this dirt collection volume offers the possibility of collecting a large amount of dirt without the oil filter becoming clogged.

The bearing unit can comprise at least one plain bearing and/or at least one rolling bearing.

Furthermore, the present disclosure relates to a gas turbine engine with a transmission described in more detail above.

The gas turbine engine can have at least two central shafts. Oil can be introduced into the storage unit via an open oil supply and a closed oil supply. The oil feeds are fluidly connected to the bearing unit and non-rotatably connected to the planet carrier.

The oil can be guided downstream of the opening of the open oil supply for the oil when the planet carrier is rotating by the centrifugal force acting on the oil in the open oil supply in the direction of the bearing unit.

The first central shaft is designed to be operated at a higher speed than the second central shaft. The second central shaft is coupled to the planetary gear. The closed oil supply of the planet carrier is connected to a pressure side of an oil pump, the drive shaft of which is connected to the first central shaft. An oil supply unit is also provided, from which oil is introduced into the open oil supply.

The gas turbine engine according to the present disclosure includes a combination of two oil feed lines of a high-performance transmission arranged in a power flow of a low-pressure turbine region. The first feed line or the closed oil supply provides a sealed and therefore closed oil transfer in order to supply oil to oil consumers of the planetary gear d. H. in this case to pump to the bearing unit of the planetary gear. Since the first oil feed line represents a closed system, an oil filter of the closed oil feed can be arranged upstream of the oil feed into the planetary gear. This means that the oil filter of the closed oil supply is accessible and can be serviced.

The second feed line or the open oil supply represents a device that includes an oil filter that is arranged in an open system. With such an open oil supply The oil can be introduced into a groove or a groove via oil jets, ie injected or sprayed. The centrifugal force acting on the oil in the channel causes a centrifugal pumping effect and pumps the oil to oil consumers or to the bearing unit of the planetary gear, which can include at least one plain bearing and/or at least one rolling bearing.

The different type of oil supply contributes significantly to reducing the probability of failure of the bearing unit because the possibility of a complete interruption of the oil supply is low.

Since dirt can enter the rotating system via the open oil supply, the oil filter of the open oil supply must be integrated into the rotating system and thus into the rotating area of the planetary gear. This makes it difficult or impossible to service the oil filter.

In the gas turbine engine according to the present disclosure, dirt can be flushed out of the oil filter of the open oil supply during starting processes of the gas turbine engine and at low speeds of the central shafts. The closed oil supply can be used for this, which introduces a sufficient oil volume flow into the bearing unit during a starting process of the gas turbine engine and at low speeds of the central shafts and thus of the gas turbine engine.

This is made possible by the oil pump of the closed oil supply being connected to and driven by the first central shaft, which is each operated at a higher speed than the second central shaft. The first central shaft also has a higher speed than the second central shaft during starting processes. Therefore, the oil pump of the closed oil supply is driven at a sufficient speed when the gas turbine engine is switched on according to the present disclosure and a desired high oil volume flow is introduced into the bearing unit.

Since the oil transport in the open oil supply depends on the centrifugal force acting on the oil, the centrifugal force is not sufficiently high during switching on of the gas turbine engine and at low speeds of the gas turbine engine to lead oil to the bearing unit via the open oil supply. The closed oil supply and the open oil supply are in the area of the oil consumer of the planetary gear, i.e. H. In the present case in the area of the bearing unit of the plain bearing in connection with each other.

If the oil pressure in the area of the bearing unit is sufficiently high, oil is introduced from the area of the bearing unit into the open oil supply and guided in the direction of the opening of the open oil supply. This causes flow through the oil filter in the open oil feed in the opposite direction to the direction of flow of the oil as the centrifugal force pumps the oil in the open oil feed towards the bearing unit. Dirt deposits in the area of the oil filter are then washed out. The resulting self-cleaning of the oil filter effectively counteracts clogging of the filter over the operating time of a gas turbine engine in a simple manner, which means that an oil supply to the bearing unit is permanently guaranteed, even via the open oil supply, without having to maintain the oil filter.

The oil supply unit, which is assigned to the open oil supply, can be driven by the first central shaft and/or by the second central shaft.

According to a further aspect of the present disclosure, a method for determining a filter fineness of a filter device of a transmission with at least one planetary gear is provided. The planet gear is rotatably mounted on a rotatable planet carrier via a bearing unit. The bearing unit can be supplied with oil via an oil supply. The oil supply is carried out upstream of the storage unit with the filter device for the oil with which the storage unit can be supplied.

• - Ermitteln der maximal am Getriebe anliegenden Antriebsleistung P;
• - Ermitteln der maximalen Winkelgeschwindigkeit ω_B des Planetenträgers;
• - Berechnen der Filterfeinheit der Filtereinrichtung in Abhängigkeit der maximal am Getriebe anliegenden Antriebsleistung P und der maximalen Winkelgeschwindigkeit ω_B des Planetenträgers gemäß der Gleichung

$$d_{Filter}=x\cdot \sqrt[-2]{\frac{P^2}{{\omega }_B^2}+{\omega }_B^4},$$

wobei die Variable x gleich dem Verhältnis zwischen der Lagerlast, die sich bei anliegender maximaler Antriebsleistung P im Bereich der Lagereinheit und bei Vorliegen der maximalen Winkelgeschwindigkeit ω_B des Planetenträgers einstellt, und der Filterfeinheit der Filtereinrichtung ist.The procedure has the following steps:

• - Determine the maximum drive power P available at the transmission;
• - Determine the maximum angular velocity ω _B of the planet carrier;
• - Calculating the filter fineness of the filter device depending on the maximum drive power P applied to the transmission and the maximum angular velocity ω _B of the planet carrier according to the equation

$$d_{Filter}=x\cdot \sqrt[-2]{\frac{P^2}{{\omega }_b^2}+{\omega }_b^4},$$

where the variable x is equal to the ratio between the bearing load, which occurs when the maximum drive power P is present in the area of the bearing unit and when the maximum angular velocity ω _B of the planet carrier is present, and the filter fineness of the filter device.

The ratio x can have values between 2 and 385, preferably between 4.5 and 240 and preferably between 9 and 145.

In addition, a method for operating the transmission described in more detail above is proposed. When the gearbox is in operation, the bearing unit is supplied with oil from a closed oil supply. At a speed of the planet carrier greater than a threshold value, oil flows through an oil supply that is open on the supply side and a filter device or an oil filter of the open oil supply in the direction of the bearing unit. In addition, when the speed of the planet carrier is lower than the threshold value, oil flows through the open oil supply and its oil filter starting from the bearing unit.

This ensures in a simple manner that the bearing unit of the gearbox is supplied with oil from both the closed oil supply and the open oil supply at higher speeds of the planet carrier. In addition, the method according to the present disclosure ensures that the bearing unit operates at lower speeds, i.e. H. In the present case, at speeds lower than the speed threshold, oil is applied to the closed oil supply and, in addition, the open oil supply is acted upon by oil against the flow direction of the oil, which the oil has in the open oil supply when the bearing unit is supplied with oil from the open oil supply flows through and the oil filter is cleaned or washed.

It will be understood by those skilled in the art that a feature or parameter described in relation to one of the above aspects may be applied to any other aspect provided they are not mutually exclusive. Further, any feature or parameter described herein may be applied to any aspect and/or combined with any other feature or parameter described herein, as long as they are not mutually exclusive.

The present disclosure is not limited to the specified combinations of features of the independent claims or the claims dependent thereon. There are also possibilities to combine individual features with one another, including those that emerge from the claims, the following description of embodiments and directly from the drawing. The reference of the claims to the drawings through the use of reference numerals is not intended to limit the scope of the claims.

• 1 eine schematisierte Längsschnittansicht eines Gasturbinentriebwerkes;
• 2 eine vergrößerte Teillängsschnittansicht eines stromaufwärtigen Abschnitts eines Gasturbinentriebwerks;
• 3 eine Alleindarstellung eines Getriebes für ein Gasturbinentriebwerk;
• 4 eine stark vereinfachte Darstellung eines Getriebes eines Gasturbinentriebwerkes, das über eine geschlossene Ölzuführung und eine offene Ölzuführung mit Öl versorgbar ist;
• 5 eine Teillängsschnittansicht des Getriebes gemäß 4, die Bereiche der geschlossenen Ölzuführung und der offenen Ölzuführung zeigt, über die eine Lagereinheit mit Öl versorgbar ist, das ein Gleitlager umfasst;
• 6 eine dreidimensionale Teilansicht der offenen Ölzuführung des Getriebes gemäß 4;
• 7 eine Teillängsschnittansicht des Getriebes gemäß 4, die Bereiche der geschlossenen Ölzuführung und der offenen Ölzuführung zeigt, über die eine Lagereinheit mit Öl versorgbar ist, das ein Wälzlager umfasst;
• 8 einen Verlauf eines Öldrucks in der Lagereinheit des Getriebes gemäß 5 bzw. gemäß 7 und einen Verlauf eines Öldrucks in der offenen Ölzuführung über der Drehzahl eines Planetenträgers des als Planetengetriebe ausgeführten Getriebes; und
• 9 einen Verlauf eines Ölvolumenstromes zwischen der Lagereinheit gemäß 5 bzw. gemäß 7 und einer Öffnung der offenen Ölzuführung über der Drehzahl des Planetenträgers des Getriebes gemäß 4.

Preferred further developments result from the subclaims and the following description. Embodiments of the subject matter according to the present disclosure are, without being limited to this, explained in more detail with reference to the drawing. This shows:

• 1 a schematic longitudinal sectional view of a gas turbine engine;
• 2 an enlarged partial longitudinal sectional view of an upstream portion of a gas turbine engine;
• 3 a sole representation of a gearbox for a gas turbine engine;
• 4 a highly simplified representation of a gearbox of a gas turbine engine, which can be supplied with oil via a closed oil supply and an open oil supply;
• 5 a partial longitudinal section view of the transmission according to 4 , which shows areas of the closed oil supply and the open oil supply, via which a bearing unit which includes a plain bearing can be supplied with oil;
• 6 a three-dimensional partial view of the open oil supply of the transmission 4 ;
• 7 a partial longitudinal section view of the transmission according to 4 , which shows areas of the closed oil supply and the open oil supply, via which a bearing unit can be supplied with oil, which includes a rolling bearing;
• 8th a course of oil pressure in the bearing unit of the transmission 5 or according to 7 and a curve of an oil pressure in the open oil supply over the speed of a planetary carrier of the gearbox designed as a planetary gearbox; and
• 9 a course of an oil volume flow between the bearing unit 5 or according to 7 and an opening of the open oil supply above the speed of the planet carrier of the transmission 4 .

1 illustrates a gas turbine engine 10 with a main axis of rotation 9. The engine 10 includes an air inlet 12 and a thrust fan 23 that generates two air streams: a core air stream A and a bypass air stream B. The gas turbine engine 10 includes a core 11 that receives the core air stream A. The engine core 11 includes, in axial flow order, a low-pressure compressor 14, a high-pressure compressor 15, a combustor 16, a high-pressure turbine 17, a low-pressure turbine 19 and a core thruster 20. An engine nacelle 21 surrounds the gas turbine engine 10 and defines a bypass duct 22 and a bypass thruster 18. The bypass airflow B flows through the bypass channel 22. The fan 23 is attached to the low-pressure turbine 19 via a shaft 26 and a planetary gear 30 and is driven by it. The wave 26 is also referred to as a core wave.

In use, the core air flow A is accelerated and compressed by the low-pressure compressor 14 and fed into the high-pressure compressor 15, where further compression occurs. The compressed air expelled from the high pressure compressor 15 is directed into the combustion device 16 where it is mixed with fuel and the mixture is burned. The resulting hot combustion products then propagate through and thereby drive the high pressure and low pressure turbines 17, 19 before being expelled through the nozzle 20 to provide some thrust. The high-pressure turbine 17 drives the high-pressure compressor 15 through a suitable connecting shaft 27, which is also referred to as a core shaft. The fan 23 generally provides the majority of the thrust. The epicyclic gear 30 is a reduction gear.

An exemplary arrangement for a geared fan gas turbine engine 10 is shown in 2 shown. The low-pressure turbine 19 (see 1 ) drives the shaft 26, which is coupled to a sun gear 28 of the epicyclic gear arrangement 30. Several planet gears 32, which are coupled to one another by a planet carrier 34, are located radially outside of the sun gear 28 and mesh with it and are each rotatably connected to the planet carrier 34 in a rotationally fixed manner and in 3 Support elements or planetary bolts 42 shown in more detail are arranged. The transmission 30 includes 4 planetary gears 32 and can be designed with 3 to 7 planetary gears 32 depending on the respective application.

The planet carrier 34 restricts the planet gears 32 from rotating synchronously about the sun gear 28 while allowing each planet gear 32 to rotate about its own axis on the planet pins 42, which are static axes. The planet carrier 34 is coupled to the fan 23 via linkage 36 to drive its rotation about the engine axis 9. An external gear or ring gear 38, which is coupled to a stationary support structure 24 via linkage 40, is located radially outside of the planet gears 32 and meshes with it.

It is noted that the terms “low pressure turbine” and “low pressure compressor” as used herein may be construed to mean the lowest pressure turbine stage and the lowest pressure compressor stage, respectively (i.e., not the fan 23) and/or the turbine and compressor stages interconnected by the lowest speed connecting shaft 26 in the engine (i.e. not including the transmission output shaft that drives the fan 23). In some literature, the “low pressure turbine” and “low pressure compressor” referred to herein may alternatively be known as the “medium pressure turbine” and “medium pressure compressor”. Using such alternative nomenclature, the blower 23 may be referred to as a first compression stage or lowest pressure compression stage.

The epicyclic gear 30 is in 3 shown in more detail as an example. The sun gear 28, the planetary gears 32 and the ring gear 38 each include teeth around their periphery for meshing with the other gears. However, for the sake of clarity, only exemplary sections of the teeth are shown in 3 shown. Although four planetary gears 32 are illustrated, it will be apparent to those skilled in the art that more or fewer planetary gears 32 may be provided within the scope of the claimed invention. Practical applications of an epicyclic gear train 30 generally include at least three planet gears 32.

This in 2 and 3 Planetary gear transmission 30 shown as an example is a planetary transmission in which the planet carrier 34 is coupled to an output shaft via linkage 36, with the ring gear 38 being fixed. However, any other suitable type of epicyclic gear 30 may be used. As another example, the epicyclic gear 30 may be a star arrangement in which the planet carrier 34 is held fixed while allowing the ring gear (or outer gear) 38 to rotate. With such an arrangement, the fan 23 is driven by the ring gear 38. As another alternative example, the transmission 30 may be a differential gear in which both the ring gear 38 and the planet carrier 34 are allowed to rotate.

The geometry of the gas turbine engine 10 and components thereof are defined by a conventional axis system having an axial direction X (aligned with the axis of rotation 9), a radial direction Y (in the bottom-up direction). 1 ) and a circumferential direction U (perpendicular to the view in 1 ). The axial, radial and circumferential directions X, Y and U are perpendicular to each other.

4 shows the planetary gear 30 of the gas turbine engine 10 in a simplified view. The planetary gear 30 can be supplied with oil via an open oil supply 45. Additionally, it can It can be provided that oil is also supplied to the planetary gear 30 via a closed oil supply 46. The oil supplied to the planetary gear 30 is returned to an oil system of the gas turbine engine 10 via a return line 47 of the planetary gear 30 and from there introduced into the oil feeds 45 and 46 via oil pumps 48, 49. The oil pumps 48 and 49 can, for example, be connected to the connecting shaft 27 of the gas turbine engine 10 according to 1 are driven.

5 shows a partial longitudinal section view of the planetary gear 30 along an in 3 section line VV marked in more detail. The planet carrier 34 comprises two cheeks 34A spaced apart from one another in the axial direction X, of which only one of the two cheeks 34A is in 5 is shown. The planet bolt 42 is arranged in a rotationally fixed manner at each end in a bore 47A of the cheeks 34A of the planet carrier 34. In the area of an outside 50, the planetary bolt 42 is designed with an oil supply pocket 51. The planetary bolts 42 are each mounted in the planet carrier 34 in such a way that the oil supply pockets 51 in the circumferential direction U of the planetary bolts 42 are in each case outside a highly loaded area of bearing units 41 of the planetary gears 32, which are in the in 5 shown embodiment of the transmission 30 include plain bearings 41A, are arranged. In the present case, the oil supply pockets 51 are each designed as milling or milling on the outer sides 50 of the planetary bolts 42.

Into the in 5 shown oil supply pocket 51 of the plain bearing 41A opens into a line 52 of the open oil supply 45. In addition, a line 53 of the closed oil supply 46 also opens into the oil supply pocket 51. Oil is introduced under pressure from the oil pump 49 into an oil line 54 of the closed oil supply 46, which In the present case, it is provided running essentially in the radial direction Y in the planet carrier 34 or in the cheek 34A. The oil line 54 opens into an oil supply line 55 which runs essentially in the axial direction X in the planetary bolt 42 and which in the present case is designed as a blind hole. From the oil supply line 55 of the closed oil supply 46, another oil supply line 56 branches off, which in turn runs in the radial direction Y in the planetary bolt 42 and is connected to the line 53.

In the present case, the open oil supply 45 comprises a channel 57 which is designed with an opening 58 in the radial direction Y inwards. The groove 57 and the opening 58 extend in the circumferential direction U over the entire circumference of the planet carrier 34. The groove 57 is connected in a rotationally fixed manner to the planet carrier 34 and also to the planetary bolt 42. In a radially outer region 59 of the channel 57, the channel 57 is connected to an oil supply line 60 which runs essentially in the axial direction

During operation of the gas turbine engine 10, oil is fed from the oil pump 48 under pressure to an oil supply unit 61 and injected via the oil supply unit 61 through the opening 58 into the channel 57. In the channel 57, depending on the speed of rotation of the planet carrier 34, the injected oil is guided in the direction of the radially outer region 59 of the groove 57 by the centrifugal force acting on the oil and introduced into the line 60. The oil introduced into the channel 57, which is in contact with the lateral boundary walls 57A, 57B of the channel 57, is initially accelerated in the circumferential direction U by the rotation of the planet carrier 34 and thus also the rotation of the boundary walls 57A, 57B guided outwards in the radial direction Y by the centrifugal force then acting on the oil in the groove 57. In other words, the oil is accelerated in the circumferential direction U of a so-called collecting area or the channel 57 of the open oil supply 45 and a substantially radial flow is imposed on the oil in the channel 57 in the direction of the radially outer region 59 of the channel or the collecting area.

In order to avoid undesired entry of dirt through the opening 58 into the open oil supply 45, an oil filter 62, preferably made of metal, is arranged in the groove 57, through which the oil is guided, which is introduced into the groove 57 via the opening 58. The oil is cleaned in the area of the oil filter 62 before it is introduced into the oil supply line 60 via the radially outer area 59 of the channel 57.

The oil filter 62 extends in the open oil supply 45 in areas opposite to the flow direction of the oil from the opening 58 of the channel 57 in the direction of the oil supply pocket 51 of the bearing unit 41 into the flow path of the oil. In addition, the oil filter 62 is firmly connected to boundary walls 57A, 57B of the channel 57 in a filter section 63, which faces the radially outer channel region 59. From the filter section 63, a further filter section 64 extends radially inwards in the channel 57, through which the oil can flow in the channel 57 and which runs at a distance from the boundary walls 57A, 57B or the side walls of the channel 57 in the interior of the channel 57 is.

The filter section 63 is in the in 6 shown in more detail as a cylindrical separator extending in the groove 57 in the circumferential direction U and in the axial direction X of the groove 57 Wall executed, which is connected to the side boundary walls 57A, 57B of the gutter. In addition, the partition 63 is designed with a plurality of through openings 65 spaced apart from one another in the circumferential direction U of the channel 57, in the area of which a further filter section 64 is provided. The further filter sections 64 are shown in FIG 6 The manner shown in more detail is each conical or pylon-shaped. In addition, the further filter sections 64 are each connected to the partition 63 in the area of their base surfaces and extend radially inwards away from the partition 63 in the direction of the open area of the channel 57.

The above-described design of the oil filter 62 prevents the oil filter 62 from being completely clogged by filtered-out dirt particles in a structurally simple manner. This is the case because the dirt particles slide radially outwards on the steep walls of the conical additional filter sections 64 during operation of the gas turbine engine 10 and thus of the planetary gear 30 by the then acting centrifugal force. The dirt particles collect and remain downstream of the opening 59 on the side of the partition 63 that faces the opening 59 without clogging or closing the further filter sections 64.

For the dirt particles thrown off in the direction of the partition 63, there is a comparatively large volume inside the channel 57 which extends in the circumferential direction U, in the radial direction Y and in the axial direction X between the further filter sections 64 and in which the dirt particles are caught and collected , without significantly influencing the flow resistance for the oil in the area of the oil filter 62. The further filter sections 64 projecting radially inwards also ensure that even if there is a certain layer height of the protective particles, starting from the radial inside of the partition 63 and inwards in the radial direction X of the channel 57, the oil still passes through essentially unhindered can flow through the oil filter 62.

As already briefly mentioned above, there is the possibility that the plain bearing 41A of the bearing unit 41 or the oil supply pocket 51 can be supplied with oil via the closed oil supply 46 in addition to the open oil supply 45. Due to the closed or sealed design of the closed oil supply 46, the oil supplied via the closed oil supply 46 can be filtered at any point outside the planetary gear 30. The oil filter 74 of the closed oil supply 46, which is preferably designed as a paper filter, is arranged downstream of the oil pump 49.

It is possible that the oil filter 74 is positioned on the housing side and does not rotate with the planet carrier 34. Alternatively or in addition to this, it can also be provided that the oil filter of the closed oil supply 46 is also arranged in the planet carrier 34 and rotates with it during operation of the gas turbine engine 10. This alternative or additional position of the oil filter is marked in more detail in the drawing under reference number 741.

Again, in addition or as an alternative to the last-mentioned arrangement options for the oil filter of the closed oil supply 46, the oil filter can also be arranged in the planetary bolt 42 and rotate with the planetary carrier 34 during operation of the gas turbine engine 10. This further alternative or additional position of the oil filter of the closed oil supply 46 is marked in more detail in the drawing under the reference number 742.

In addition, the redundant oil supply via the closed oil supply 46 into the plain bearing 41A offers the possibility of applying oil to the plain bearing 41A even at low speeds of the planet carrier 34. This is advantageous because at low speeds of the planet carrier 34, i.e. H. below a defined speed threshold, the centrifugal force, which acts on the oil in the groove 57 when the planet carrier 34 is rotating, is not yet sufficient to apply oil to the sliding bearing 41A via the open oil supply 45 to the required extent.

If the oil is introduced into the oil supply pocket 51 via the closed oil supply 46 with a correspondingly high pressure, at least part of the oil, which is introduced into the oil supply pocket 51 via the closed oil supply 46, is fed into the radially outer one via the line 52 and the oil supply line 60 Channel area 59 initiated. The oil is then guided through the oil filter 62 in the direction of the opening 58 of the channel 57. This means that in the last described operating state of the planetary gear 30 and the gas turbine engine 10, oil flows through the oil filter 62 in a direction so that dirt particles adhering to the outside of the further filter sections 64 are washed out of the oil filter and discharged from the groove 57.

Such an operating state of the gas turbine engine 10, in which the planet carrier 34 is only operated at low speeds, occurs in particular during starting processes of the gas turbine engine 10, during which the Connecting shaft 27, which represents a so-called high-pressure shaft of the gas turbine engine 10, rotates at a higher speed than the so-called low-pressure shaft 26 of the gas turbine engine 10, which is in rotary connection with the planetary gear 30.

This means that the oil pump 49, which is preferably designed as a constant pump, the delivery volume of which increases linearly with the drive speed, leads an oil volume towards the oil supply pocket 51 via the closed oil supply 46, which is sufficient to supply the plain bearing 41 and the oil filter 62 accordingly rinse and clean.

7 shows one 5 corresponding partial longitudinal section view of a further embodiment of the planetary gear 30 along the in 3 section line VV marked in more detail. The planetary gear 30 according to 7 differs only in some areas from the planetary gear 30 5 , which is why the basic functionality of the planetary gear 30 according to 7 to the above description 5 and 6 reference is made and below essentially only to the differences between the planetary gear 30 according to 5 and the planetary gear 30 according to 7 will be discussed in more detail. Furthermore, in the following description 7 for structurally and functionally identical components of the planetary gear 30 according to 7 the same reference numbers as in the description of the planetary gear 30 5 used.

The bearing unit 41 of the planetary gear 30 according to 7 comprises a rolling bearing 41 B, which is supplied with oil essentially in the manner described above via the open oil supply 45 and the closed oil supply 46. The oil line 54 of the closed oil supply 46 opens into the oil supply line 55, which runs in the axial direction X in a bolt 42A of the planetary bolt 42. The bolt 42A is inserted into a sleeve 42B of the planetary bolt 42 and is connected to it in a rotationally fixed manner. In addition, the sleeve 42B is in operative connection with the planet carrier 34 in a rotationally fixed manner. The oil supply line 55 is connected via a radial bore 70 to an annular space 71 extending in the circumferential direction U in the planetary bolt 42. At the in 7 In the illustrated embodiment of the planetary gear 30, the annular space 71 is provided between the sleeve 42B of the planetary bolt 42 and the bolt 42A of the planetary bolt 42 and is delimited by these in the radial direction Y and in the axial direction X.

In addition, the annular space 71 is connected to the oil supply line 60 of the open oil supply 45 via a further radial bore 72. The oil supply line 60 runs in the axial direction X in the bolt 42A. In addition, the annular space 71 is connected to the bearing gap of the rolling bearing 41 B via additional radial bores 73 which are provided in the sleeve 42B, the rolling bearing 41 B being able to be supplied with oil from the annular space 71 via the additional radial bores 73.

During operation of the gas turbine engine 10, oil is supplied in the manner described above by the oil pump 48 under pressure to the oil supply unit 61 and injected via the oil supply unit 61 through the opening 58 into the channel 57. In the channel 57, depending on the speed of rotation of the planet carrier 34, the injected oil is guided in the direction of the radially outer region 59 of the groove 57 by the centrifugal force acting on the oil and introduced into the line 60.

In order to avoid undesired entry of dirt through the opening 58 into the open oil supply 45, the oil filter 62 is arranged in the groove 57, which, like the planetary gear 30, according to 5 is executed.

If the oil is introduced into the annular space 71 via the closed oil supply 46 with a correspondingly high pressure, at least part of the oil that flows into the annular space 71 via the closed oil supply 46 is fed into the radially outer one via the further radial bore 72 and the oil supply line 60 Gutter area 59 led. The oil then flows through the oil filter 62 in the direction of the opening 58 of the channel 57. In the last described operating state of the planetary gear 30 and the gas turbine engine 10, the oil flows through the oil filter 62 in a direction that flows through the other filter sections 64 on the outside Adhering dirt particles are washed out of the oil filter and discharged from the channel 57.

Such an operating state of the gas turbine engine 10, in which the planet carrier 34 is operated only at low speeds, occurs in particular during starting processes of the gas turbine engine 10, during which the connecting shaft 27, which represents a so-called high-pressure shaft of the gas turbine engine 10, rotates at a higher speed than the so-called Low-pressure shaft 26 of the gas turbine engine 10, which is in rotary connection with the planetary gear 30.

This means that the oil pump 49, which is preferably designed as a constant pump, the delivery volume of which increases linearly with the drive speed, leads an oil volume towards the annular space 71 via the closed oil supply 46, which is sufficient to move the rolling bearing 41 B ensure that the oil filter 62 is flushed and cleaned accordingly.

This means that the closed oil supply 46 and the open oil supply 45 are in accordance with the embodiment of the planetary gear 30 7 via the annular space 71 in a comparable manner to the oil supply lines 45 and 46 of the planetary gear 30 5 communicate with each other via the oil supply pocket 51 in order to ensure an oil supply to the bearing unit 41 or the plain bearing 41A or the rolling bearing 41B.

In addition, the direction of flow of the oil with which the oil filter 62 of the planetary gear 30 changes according to 5 or according to 7 is flowed through, each in the same way depending on the pressure gradient between the pressure in the oil supply pocket 51 and the pressure in the channel 47 or between the pressure in the annular space 71 and the pressure in the channel 57.

With a positive pressure gradient, i.e. that is, if the pressure in the channel 57 is greater than the pressure in the oil supply pocket 51 or if the pressure in the channel 57 is greater than the pressure in the annular space 71, then the bearing unit 41 is also supplied with oil via the open oil supply 45. In contrast, the oil filter 62 is activated at a negative pressure gradient, i.e. that is, if the pressure in the channel 57 is smaller than the pressure in the oil supply pocket 51 or if the pressure in the channel 57 is smaller than the pressure in the annular space 71, through which from the oil supply pocket 51 or from the annular space 71 in the direction of Channel 57 guided oil flushed and cleaned.

8th shows speed-dependent curves of an oil pressure p51 in the oil supply pocket 51 or an oil pressure p71 in the annular space 71 and an oil pressure p57 in the channel 57. Furthermore shows 9 a speed-dependent course of an oil volume flow V_ÖL through the open oil supply 45.

Out of 8th It can be seen that the oil pressure p57 in the channel 57 below a threshold value n34threshold of the speed n34 of the planet carrier 34 is smaller than the pressure p51 in the oil supply pocket 51 or is smaller than the pressure p71 in the annular space 71. This leads to oil below of the threshold value n34threshold of the speed n34 of the planet carrier 34 is guided from the oil supply pocket 51 or from the annular space 71 in the direction of the opening 59 of the channel 57 and the oil filter 62 is flushed with oil in the manner described above, thus cleaning the oil filter 62 takes place. Above the threshold value n34thwell, the pressure p57 in the channel 57 exceeds the pressure p51 in the oil supply pocket 51 or the pressure p71 in the annular space 71. This causes oil to flow out from the opening 58 of the channel 57 and through the oil filter 62 in addition to the oil volume flow the closed oil supply 46 is introduced into the oil supply pocket 51 or into the annular space 71.

According to the illustration in 9 the oil volume flow V_Oil has a negative sign at speeds n34 of the planet carrier 34 smaller than the threshold value n34swell and a positive sign at speeds n34 of the planet carrier 34 greater than the threshold value n34swell. This means that at speeds n34 smaller than the threshold value n34swell, oil is introduced from the oil supply pocket 51 or from the annular space 71 into the channel 57. In contrast, oil is introduced from the channel 57 into the oil supply pocket 51 or into the annular space 71 when the speed n34 of the planet carrier 34 is greater than the threshold value n34thwell.

The filter finenesses d _Filter62 and d _Filter74 of the filter devices or the oil filters 62 and 74 are determined depending on the maximum drive power P applied to the gear 30 and the maximum angular velocity ω _B of the planet carrier 34 and / or the gear ratio of the gear 30. The filter finenesses d _filter62 and d _filter74 of the filter devices 62, 74 are in accordance with the formulaic relationship $$d_{Fil\mathrm{<figure-callout\; id="62"\; label="t\; e\; r"\; filenames="DE102022119807A1\_0009.png,DE102022119807A1\_0010.png"\; state="\{\{state\}\}">t</figure-callout>}er62/74}=x\cdot \sqrt[-2]{\frac{P^2}{{\omega }_b^2}+{\omega }_b^4}$$

depending on the maximum drive power P applied to the transmission 30 and the maximum angular velocity ω _B of the planet carrier 34. The variable x is the ratio between the bearing load, which occurs during operation with the maximum drive power P applied to the gearbox 30 and with the maximum angular velocity ω _B of the planet carrier 34 in the area of the bearing unit 41, and the filter fineness d _Filter62 or d _Filter74 Filter device 62 or 74.

The filter fineness d _Filter62 of the filter device 62 and also the filter fineness d _Filter74 of the oil filter 74 have values between 10 μm and 400 μm in order to be able to operate the transmission 30 with a desired low probability of failure and with low maintenance costs.

Depending on the respective application, it is also possible that the filter finenesses d _Filter62 and d _Filter74 of the filter devices 62, 74 have values between 25 µm and 250 µm, preferably between 50 µm and 150 µm.

The maximum drive power P applied to the transmission 30 can be in one Range from 40 MW to 100 MW, preferably between 50 MW to 60 MW. Furthermore, the maximum angular velocity of the planet carrier 34 is 105 1/s to 210 1/s, preferably 145 1/s to 190 1/s, while the gear ratio of the gear 30 is in a value range of 3 to 5.

A surface through which the oil can flow in the area of the filter devices 62 and 74 can have values in a range from 1,000 mm ² to 10,000 mm ² , preferably from 2,500 mm ² to 7,500 mm ² , depending on the respective application.

The filter finenesses d _filter62 and d _filter74 of the filter devices 62, 74 are determined in the present case depending on a kinematic viscosity of the oil that is supplied to the bearing unit 41. The viscosity of the oil at an oil temperature of 100 °C is 3 to 10 cStokes, depending on the application.

Reference symbol list

9

Main axis of rotation

10

Gas turbine engine

11

core

12

Air intake

14

Low pressure compressor

15

High pressure compressor

16

Combustion device

17

High pressure turbine

18

Bypass thrust nozzle

19

Low pressure turbine

20

Core thruster

21

Engine nacelle

22

Bypass channel

23

Thrust blower

24

Support structure

26

Shaft, connecting shaft

27

connecting shaft

28

sun gear

30

Gears, planetary gears

32

Planetary gear

34

Planet carrier

34A

cheek

36

linkage

38

ring gear

40

linkage

41

Storage unit

41A

bearings

41B

roller bearing

42

planetary bolt

42A

Planetary bolt bolt

42B

Planetary bolt sleeve

45

open oil supply

46

closed oil supply

47

Return of the gearbox 30

47A

Drilling of the cheek

48

Open oil feed oil pump

49

Oil pump of the closed oil supply

50

Outside of the planetary bolt

51

Oil supply pocket of the plain bearing 41

52

Open oil supply line

53

Line of the closed oil supply

54

Oil line of the closed oil supply

55

Oil supply line of the closed oil supply

56

additional oil supply line of the closed oil supply

57

gutter

57A, 57B

boundary wall of the gutter

58

Opening of the gutter

59

radially outer area of the channel

60

Oil supply line of the open oil supply

61

Oil supply unit

62

Open oil feed oil filter 46

63

Oil filter filter section

64

another filter section of the oil filter

65

Passage opening

70

Radial bore

71

Annular space

72

further radial bore

73

additional radial bore

74

Oil filter of the closed oil feed

A

Core airflow

b

Bypass airflow

dFilter62

Filter fineness of the filter device 62

dFilter74

Filter fineness of the filter device 74

n34

Speed of the planet carrier

n34swell

Planet carrier speed threshold

P

maximum drive power

p51

Oil pressure in the oil supply bag

p57

Oil pressure in the gutter

p71

Oil pressure in the annulus

U

Circumferential direction

V_OIL

Oil volume flow

x

Relationship

X

axial direction

Y

radial direction

ωB

maximum angular velocity of the planet carrier

Claims (22)

Transmission (30) with at least one planet gear (32), which is rotatably mounted on a rotatable planet carrier (34) via a bearing unit (41; 41A; 41B), the bearing unit (41; 41A; 41B) being via an oil supply (45, 46) can be supplied with oil, the oil supply (45, 46) upstream of the bearing unit (41; 41A; 41B) being designed with at least one filter device (62, 74) for the oil with which the bearing unit (41; 41A; 41B ) can be supplied, with a filter fineness (d _Filter62 , d _Filter74 ) of the filter device (62, 74) depending on the maximum drive power (P) applied to the gear (30) and the maximum angular velocity (ω _B ) of the planet carrier (34) and / or the translation of the transmission (30) is fixed. Gearbox after Claim 1 , characterized in that the filter fineness (d _Filter62 , d _Filter74 ) of the filter device (62, 74) according to the formula relationship $$d_{filter62/74}=x\cdot \sqrt[-2]{\frac{P^2}{{\omega }_b^2}+{\omega }_b^4}$$

is determined depending on the maximum drive power (P) applied to the gearbox and the maximum angular velocity (ω _B ) of the planet carrier (34), where x is the ratio between the bearing load, which is during operation with the maximum drive power applied to the gearbox (30) ( P) in the area of the bearing unit (41; 41A; 41 B) and when the maximum angular velocity (ω _B ) of the planet carrier (34) is present, and the filter fineness (d _Filter62 , d _Filter74 ) of the filter device (62, 74). Transmission (30) with at least one planet gear (32), which is rotatably mounted on a rotatable planet carrier (34) via a bearing unit (41; 41A; 41B), the bearing unit (41; 41A; 41B) being via an oil supply (45, 46) can be supplied with oil, the oil supply (45, 46) upstream of the bearing unit (41; 41A; 41B) being designed with at least one filter device (62, 74) for the oil with which the bearing unit (41; 41A; 41B ) can be supplied, with a filter fineness (d _Filter62 , d _Filter74 ) of the filter device (62, 74) having values between 10 µm and 400 µm. Transmission according to at least one of the above-mentioned claims, characterized in that the filter fineness (d _Filter62 , d _Filter74 ) of the filter device (62, 74) has values between 25 µm and 250 µm. Transmission according to at least one of the above-mentioned claims, characterized in that the filter fineness (d _Filter62 , d _Filter74 ) of the filter device (62, 74) has values between 50 µm and 150 µm. Gearbox according to at least one of the above-mentioned claims, characterized in that the filter fineness (d _filter62 , d _filter74 ) of the filter device (62, 74) is determined depending on a maximum drive power (P) applied to the gearbox (30), the maximum Drive power (P) is in a range from 40 MW to 100 MW, preferably from 50 MW to 60 MW. Transmission according to at least one of the preceding claims, characterized in that the filter fineness (d _filter62 , d _filter74 ) of the filter device (62, 74) is determined as a function of a maximum angular velocity (ω _B ) of the planet carrier (34), the maximum angular velocity (ω _B ) is in a range from 105 1/s to 210 1/s, preferably from 145 1/s to 190 1/s. Gearbox according to at least one of the above-mentioned claims, characterized in that the filter fineness (d _Filter62 , d _Filter74 ) of the filter device (62, 74) is determined depending on a gear ratio of the gearbox (30), which is in a value range of 3 to 5 . Transmission according to at least one of the above-mentioned claims, characterized in that 3 to 7 planetary gears (32), preferably 5 planetary gears (32) are provided. Transmission according to at least one of the above-mentioned claims, characterized in that the oil supply (46) has a filter device (74) provided on the housing side, which is preferably designed as a paper filter. Transmission according to at least one of the preceding claims, characterized in that an area through which the oil can flow in the area of the filter device (62, 74) has values in a range from 1,000 mm ² to 10,000 mm ² , preferably between 2,500 mm ² and 7,500 mm ² . Gearbox according to at least one of the preceding claims, characterized in that the filter fineness (d _filter62 , d _filter74 ) of the filter device (62, 74) for a kinematic viscosity of the oil that is supplied to the bearing unit (41; 41A; 41B) is of 3 to 10 cStokes at an oil temperature of 100 °C. Transmission according to at least one of the above-mentioned claims, characterized in that a closed oil supply (45) and/or an open oil supply (46) is/are provided. Transmission according to at least one of the above-mentioned claims, characterized in that the filter device (62, 74) is designed in one or more layers. Transmission according to at least one of the preceding claims, characterized in that the filter device (62) is provided in a region of the oil supply (46) which is provided within the rotatable planet carrier (34). Transmission according to at least one of the above-mentioned claims, characterized in that the filter device (62) is designed as a metal filter, in particular as a metal hole filter, as a metal fabric filter or as a metal mesh filter. Transmission according to at least one of the preceding claims, characterized in that the filter device (62) is designed with at least one conical filter section (64), the filter section (64) having its outside against the flow direction of the oil in the oil supply (46). or extends in the direction of flow of the oil in the oil supply (46). Transmission according to at least one of the preceding claims, characterized in that the bearing unit (41) comprises at least one plain bearing (41A) and/or at least one rolling bearing (41B). Transmission according to at least one of the preceding claims, characterized in that the ratio x has values between 2 to 385, preferably between 4.5 to 240 and preferably between 9 to 145. Gas turbine engine (10) with a gearbox (30) according to one of Claims 1 until 19 . Method for determining a filter fineness (d _Filter62 , d _Filter74 ) of a filter device (62, 74) of a transmission (30), preferably a transmission according to one of the above-mentioned claims, with at least one planet gear (32) which has a bearing unit (41; 41A; 41B) is rotatably mounted on a rotatable planet carrier (34), wherein the bearing unit (41; 41A, 41B) can be supplied with oil via an oil supply (45, 46), the oil supply (45, 46) being located upstream of the bearing unit ( 41; 41A; 41B) is designed with the filter device (62, 74) for the oil with which the bearing unit (41; 41A; 41B) can be supplied, the following steps being carried out to determine the filter fineness (d _filter62 , d _filter74 ). : - Determine the maximum drive power (P) available to the gearbox; - Determining the maximum angular velocity (ω _B ) of the planet carrier (34); - Calculating the filter fineness (d _Filter62 , d _Filter74 ) of the filter device (62, 74) depending on the maximum drive power (P) applied to the transmission and the maximum angular velocity (ω _B ) of the planet carrier (34) according to the equation $$d_{filter62/74}=x\cdot \sqrt[-2]{\frac{P^2}{{\omega }_b^2}+{\omega }_b^4},$$

_whereby Filter fineness (d _Filter62 , d _Filter74 ) of the filter device (62, 74). Procedure according to Claim 21 , characterized in that the ratio x has values between 2 to 385, preferably between 4.5 to 240 and preferably between 9 to 145.

Images