EP4170173A1 - Screw compressor with bearing lubricant channels - Google Patents

Abstract

A screw compressor (1) comprising a housing (60) defining a compression chamber (11) and a motor chamber (31), a pair of meshed compressor rotors (13, 14) having rotor shafts (15, 16), the compressor rotors (13, 14 ) are arranged in the compression chamber (11) and the axes of rotation (R1, R2) of the rotor shafts (15, 16) run parallel to one another, a drive motor (40) which is arranged in the motor chamber (31) and a motor shaft (37) for Driving at least one of the compressor rotors (13, 14), the motor shaft (37) and at least one of the rotor shafts (15, 16) being coupled to one another through a through-opening (21) between the motor chamber (31) and the compressor chamber (11). , wherein the drive motor (40) and the pair of compressor rotors (13, 14) are arranged one above the other in normal operation of the screw compressor (1), suction-side bearings (62a, 62b) for rotating the compressor rotors (13, 14) in the housing (60 ) to store, at least one motor bearing (61) to support the end of the motor shaft (37) rotatably in the housing (60), a first supply line (54) for a fluid for cooling and/or lubricating the motor bearing (61), a second Supply line (57) for a fluid for cooling and/or lubricating at least one of the suction-side bearings (62a, 62b), a discharge line (55) for the fluid from the engine bearing (61) into the compressor chamber (11), the discharge line (55 ) has a bearing bypass section (56) which, bypassing the suction-side bearings (62a, 62b), opens into the compression chamber (11).

Description

The invention relates to a screw compressor according to claim 1 and a compressor system according to claim 15, in particular for generating compressed air.

Screw compressors are known in principle from the prior art. They are used in various areas of application, for example to provide compressed air for production processes in industry. A gaseous medium is sucked in at a low pressure level, compressed by two mechanically driven compressor rotors with helical gearing based on the principle of internal compression and then pushed out of the compression chamber at a higher pressure level. The two compressor rotors are referred to as the main rotor and secondary rotor and have rotor shafts that run parallel to one another. Finally, the compressed medium is made available to a consumer for use, for example in the form of compressed air.

Typically, the two rotors are arranged in a compressor block which is connected to an engine block in order to drive the rotor shafts by motor, for example a direct drive or a belt drive can be provided, possibly also with an interposed gear. There are various designs for screw compressors, for example those in which the compressor block and the engine block are arranged horizontally next to each other or vertically one above the other. In addition, both fluid-injected in particular oil-injected, as well as dry or oil-free compressing screw compressors available. Oil-injected screw compressors comprise an oil circuit, in which oil is injected into the compression chamber for cooling and lubrication as well as for sealing gaps and is then recovered from the compressed medium in an oil separator.

From the WO 2013/126970 A1 a vertical screw compressor is known which has a common cooling and lubrication circuit for the motor, the compressor rotors and all bearings of the motor and rotor shafts. The motor chamber is not sealed against the compressor chamber. A motor bearing at the upper end of the motor shaft is connected via an axially running outlet channel to a suction-side radial bearing of the driven rotor shaft, from where the cooling and lubricating fluid continues into the compression chamber. In this respect, the arrangement of the engine bearing and the suction-side radial bearing in the fluid circuit proposed there for cooling and lubricating the bearing of the screw compressor corresponds to a series connection.

Such an integrated cooling and lubricating circuit has the disadvantage that the volume flow or the mass flow of the cooling and lubricating fluid through the engine bearing and the suction-side bearing is necessarily the same, while the respective bearing types and/or the dimensioning of the two bearings are different need for cooling and/or lubrication. There is also the problem that the suction-side bearing is supplied with a fluid that has already been preheated, and the cooling capacity can therefore be reduced.

The present invention therefore has the task of providing a screw compressor that can be operated with as little maintenance as possible and has a long service life. In particular, needs-based cooling and/or lubrication of the bearings should be possible.

This object is achieved by a screw compressor according to claim 1.

• ein Gehäuse, das eine Verdichterkammer und eine Motorkammer ausbildet,
• ein Paar von ineinandergreifenden Verdichterrotoren mit Rotorwellen, wobei die Verdichterrotoren in der Verdichterkammer angeordnet sind und die Drehachsen der Rotorwellen parallel zueinander verlaufen,
• ein Antriebsmotor, der in der Motorkammer angeordnet ist und eine Motorwelle zum Antrieb von mindestens einem der Verdichterrotoren aufweist,
  • wobei die Motorwelle und mindestens eine der Rotorwellen durch eine Durchgangsöffnung zwischen der Motorkammer und der Verdichterkammer miteinander gekoppelt sind,
  • wobei der Antriebsmotor und das Paar von Verdichterrotoren im normalen Betrieb des Schraubenverdichters übereinander, insbesondere vertikal übereinander, angeordnet sind,

• saugseitige Lager, um die Verdichterrotoren drehbar im Gehäuse zu lagern,
• mindestens ein Motorlager, um die Motorwelle endseitig drehbar im Gehäuse zu lagern,
• eine erste Zuführleitung für ein Fluid zur Kühlung und/oder Schmierung des Motorlagers,
• eine zweite Zuführleitung für ein Fluid zur Kühlung und/oder Schmierung mindestens eines der saugseitigen Lager,
• eine Abführleitung für das Fluid von dem Motorlager in die Verdichterkammer,

dadurch gekennzeichnet, dass die Abführleitung einen Lagerumgehungsabschnitt aufweist, der unter Umgehung der saugseitigen Lager in die Verdichterkammer mündet.In particular, the object is achieved by a screw compressor, in particular for generating compressed air, comprising:

• a housing forming a compressor chamber and a motor chamber,
• a pair of intermeshing compressor rotors with rotor shafts, the compressor rotors being arranged in the compressor chamber and the axes of rotation of the rotor shafts being parallel to one another,
• a drive motor which is arranged in the motor chamber and has a motor shaft for driving at least one of the compressor rotors,
  • wherein the motor shaft and at least one of the rotor shafts are coupled to each other through a through hole between the motor chamber and the compressor chamber,
  • wherein the drive motor and the pair of compressor rotors are arranged one above the other, in particular vertically one above the other, during normal operation of the screw compressor,

• suction-side bearings to rotatably mount the compressor rotors in the housing,
• at least one motor bearing to support the end of the motor shaft rotatably in the housing,
• a first supply line for a fluid for cooling and/or lubricating the engine bearing,
• a second supply line for a fluid for cooling and/or lubricating at least one of the bearings on the suction side,
• a discharge line for the fluid from the engine mount into the compressor chamber,

characterized in that the discharge line has a bearing bypass section which opens into the compression chamber bypassing the suction-side bearings.

The housing can be constructed in several parts and in particular comprises a motor housing and a compressor housing which are firmly connected to one another. A motor housing and a compressor housing preferably directly adjoin one another, and they can have a common intermediate housing wall or separate intermediate housing walls. In particular, no seal (shaft seal) is provided for sealing the passage opening. It would also be conceivable, a gear housing between the motor housing and the Provide compressor housing in which an intermediate gear for coupling the motor shaft and at least one rotor shaft is arranged.

The axis of rotation of the motor shaft and the axis of rotation of a rotor shaft preferably run coaxially, with the motor shaft and a driven rotor shaft being able to be connected to one another in a torque-proof manner, preferably directly, or being designed in one piece. A common axis of rotation preferably runs approximately or exactly vertically when the screw compressor is operated in a normal state, i.e. in particular when it is arranged in the intended spatial position (in particular for generating compressed air), in particular the installed position. In particular, a motor block and a compressor block of the screw compressor, which in particular comprise the motor housing or the compressor housing, are arranged one above the other, wherein the motor housing and the compressor housing can also be arranged one above the other laterally offset from one another. The motor housing is preferably arranged above the compressor housing, so that in particular a fluid supplied to the motor bearing for cooling and/or lubrication flows in the direction of the compressor chamber due to gravity. A medium to be compressed can flow into the compression chamber through an intake opening on a suction side of the compressor block and can flow out through an outlet opening on a pressure side of the compressor block. The suction side is preferably located on the side of the compressor rotors facing the drive motor, while the pressure side is preferably located on the side of the compressor rotors further away from the drive motor.

A motor bearing, preferably a radial bearing, for example a deep groove ball bearing, is preferably provided, it being possible for the at least one motor bearing to also include an axial bearing. In particular, the motor shaft is supported only at its upper end via the motor bearing, while the lower end (without a gear between the motor and the compressor rotors) is connected to a rotor shaft. The motor mount is supported in particular in the motor housing, preferably in an upper housing part thereof, more preferably in an inserted cover element. The rotor shafts are in particular mounted on both sides, so that each compressor rotor is mounted by a suction-side and a pressure-side bearing. The suction-side bearings are preferably radial bearings, for example cylindrical roller bearings, and the pressure-side bearings preferably (each) comprise a radial bearing and a Thrust bearings, such as a cylindrical roller bearing and an angular contact ball bearing. Depending on the size of the compressor, two angular contact ball bearings connected in series (tandem bearings) can also be provided. A rotor shaft or the motor shaft may extend into or through the through hole between the motor chamber and the compressor chamber. The suction-side bearings can sit on a rotor shaft or the motor shaft and can be supported in particular in the motor housing or in the compressor housing.

A supply line or discharge line can be understood to mean, for example, a channel that is formed in particular in the housing, e.g. as a bore, or a pipeline that runs, for example, in suitable recesses in the housing. The fluid for cooling and/or lubrication is preferably oil. Multiple storage bypass sections may be provided. A bearing bypass section preferably bypasses the (all) suction-side bearings (radial and/or axial bearings) and opens directly into the compression chamber. In particular, a bearing bypass section is formed in such a way that it runs past the suction-side bearings, preferably at a distance therefrom, particularly preferably inside the housing. However, it is also conceivable to provide the bearing bypass section (in part) as a line running outside the housing, for example with tubing. A bearing bypass section serves in particular to direct the fluid around the suction-side bearings on its flow path from the engine bearing into the compression chamber. The first and/or second supply line can be connected directly or indirectly to an external fluid supply, in particular a fluid circuit of the screw compressor.

A screw compressor according to the invention with a bearing bypass section of the discharge line has the advantage that the same fluid flow that has previously flowed through the motor bearing is not used for cooling and/or lubricating a suction-side bearing. In this way, on the one hand, volume or mass flows of a fluid for the engine mount and the intake-side mount can be selected or adjusted differently. In particular, a fluid flow can be tailored to the cooling or lubricating requirement of one of the bearings (or both bearings), for example with regard to its rolling pairing, size, rotational speed or shaft diameter and/or load to be removed. For example, the cooling and/or lubricating requirements for a deep groove ball bearing can be different than for a cylindrical roller bearing. In addition, at least one preferably both bearings on the suction side are supplied with fresh fluid for cooling through the second feed line, which fluid has not already been preheated by the cooling of the engine bearing and/or heating along the discharge line. Cooling and/or lubricating the respective bearing as required or as precisely as possible can extend the service life of both the engine bearing and the bearing on the suction side. As a result, the service life and maintenance intervals of the screw compressor can be extended.

In an advantageous development of the invention, at least one cooling channel is provided in the housing, in particular in a cooling jacket of the drive motor, from which the first supply line and/or the second supply line branches off. Cooling ducts can extend, for example as ring-segment-shaped recesses or slots, within a cooling jacket in the axial direction along the drive motor and can preferably be distributed over the circumference of the cooling jacket. Fluid for cooling the drive motor can be fed into a cooling channel or a plurality of cooling channels via a fluid inlet of the screw compressor. The heated fluid can be collected on an underside of the cooling ducts, for example by means of a collecting line, and diverted into an injection line for injection into the compression chamber. In an alternative embodiment, the fluid is guided through the (annular segment-shaped) cooling channels one after the other, preferably by deflection. The fluid moves up and down alternately in the cooling channels. With this design, all fluid flow can be diverted from a single cooling passage for injection into the compression chamber, eliminating the need for a manifold. A branch opening for a first and/or second supply line can be provided in an inner surface of at least one cooling channel. The first feed line preferably branches off from an upper end of a cooling duct, in particular approximately at the height of the engine mount, preferably in the radial direction towards the engine mount. The second feed line preferably branches off at a lower end of a cooling channel, in particular approximately at the level of one of the suction-side bearings in the radial direction inwards or above the suction-side bearing in the axial direction downwards. The diameter of the first and/or second feed line or the branch opening can be adapted to a desired fluid volume flow for the engine mount or the intake-side mount. By branching off a supply line from a cooling channel, a fluid flow for cooling and/or lubricating a bearing is in Adjustable in a structurally simple manner, since no additional connections of the screw compressor to a fluid circuit have to be provided. In addition, this ensures a compact design of the screw compressor.

In an advantageous development of the invention, at least one fluid connection is provided, via which the first feed line and/or the second feed line can be connected to a preferably external fluid reservoir, in particular an oil separator. Fluid can be supplied to the engine mount and/or the suction-side mounts via a fluid connection for a fluid reservoir, which is located in particular outside of the screw compressor (external), without being diverted from a cooling channel. In this way, heating of the fluid in the cooling channels before the fluid reaches the respective bearing can be prevented.

In particular, the fluid connection for the first feed line is arranged at the level of the motor bearing, in particular on the side of the housing, and/or the fluid connection for the second feed line is arranged at the level of one of the bearings on the suction side, in particular on the side of the housing. The connection for the first supply line can also be arranged on an upper side of the motor housing, in particular on a cover element of the motor housing, in which the motor bearing is preferably supported.

With regard to the aspects of the invention described above relating to the branching off of the first and/or second supply line from a cooling channel on the one hand and a fluid connection for a first and/or second supply line with a fluid reservoir on the other hand, the possible combinations of these aspects result in various embodiments of the invention. For example, the first supply line can be branched off from a cooling channel, while the second supply line is connected to an external fluid reservoir, or vice versa. The first and the second feed line can also be branched off from a cooling channel, namely from the same or different, with no additional fluid connection being provided apart from a fluid connection for the cooling channels. A common fluid connection or a separate fluid connection for an external fluid reservoir can also be provided for the first and the second supply line, while no branching off of a supply line from a cooling channel is provided. Also are Embodiments are conceivable, although not preferred, in which a feed line is fed both from a branch of a cooling channel and via an additional fluid connection through an external fluid reservoir.

In an advantageous development of the invention, the second supply line includes branch channels to each of the suction-side bearings. In particular, two suction-side bearings are provided, preferably one for each of the two rotor shafts, which can be supplied with fluid for cooling and/or lubrication via a branch channel. The branch channels can have different diameters, in particular tailored to the cooling and/or lubricating requirements of the respective suction-side bearing.

Alternatively, the second feed line can (only) be connected to the suction-side bearing of one of the two rotors, with a connecting channel being provided between the suction-side bearings of both rotors in order to supply oil to the suction-side bearing of the other rotor. This embodiment requires less space in the housing. The connecting duct can also be easier to manufacture than an additional branch duct.

In an advantageous development of the invention, the discharge line is designed as a separate fluid line, which in particular runs parallel to a cooling duct of the drive motor, at least in sections, preferably inside the cooling jacket of the drive motor. The discharge line preferably runs through an upper housing part, the cooling jacket and a lower housing part of the motor housing, the discharge line having in particular horizontal line sections and vertical line sections which are each designed as bores, for example. Diagonally running line sections are also possible. A separate fluid line as a discharge line has the advantage that the fluid is only slightly heated on the flow path past the drive motor, in particular through the cooling jacket. A discharge line could run as a pipe through a cooling duct, with the pipe being connected to a bearing bypass section. Alternatively, the discharge line could run (partially) outside the housing, in particular as a pipeline in (partly) the axial direction of the motor housing. With a sufficiently high pressure drop between the engine mount and a cooling duct, it would also be conceivable in principle to use a discharge line as a connecting line between the engine mount and a cooling duct to be carried out, wherein the bearing bypass section could be provided as a connecting line between a lower end of the duct and the compression chamber.

In an advantageous development of the invention, the bearing bypass section is designed as a channel section within the housing, which runs in particular (substantially) in the vertical direction. In this way, the suction-side bearings can be bypassed in a structurally simple manner.

In an advantageous development of the invention, the housing comprises a compressor housing and a motor housing, which are firmly (directly) connected to one another, with the suction-side bearings being supported in the compressor housing. In this way, the compressor rotors can be preassembled in the compressor housing as a compressor block before the compressor block is connected to the engine block. This simplifies assembly and maintenance of the screw compressor.

In an advantageous development of the invention, the bearing bypass section is formed at least partially within the compressor housing, in particular as a through hole, preferably in a suction-side end face of the compressor housing. It can be formed from several (straight) channel sections (holes) and in particular have an angled course. The bearing bypass portion may also extend into the motor housing or be formed solely in the compressor housing. A connecting pipe piece can be inserted as part of the bearing bypass section between a discharge line exiting at the lower housing part of the motor housing and a through hole in the compressor housing. A through hole is easy to perform.

In an advantageous development of the invention, the bearing bypass section opens into the compression chamber on the suction side, in particular in a suction-side end face of the compression chamber. It is also possible to design the bearing bypass portion such that it opens into the compression chamber (further downstream from the suction-side end face) at a point (laterally) at which the pressure is higher than the suction pressure. At the There is then a higher back pressure at the junction point of the bearing bypass section than in the intake area of the compressor chamber. This is one way of setting the flow rate across the motor mount.

In an advantageous development of the invention, the motor housing and the compressor housing have at least one pair of matching outlet or inlet openings in a common boundary surface, through which the bearing bypass section or a branch channel runs. This ensures a compact design of the screw compressor in a structurally simpler manner.

In an advantageous development of the invention, the screw compressor is designed in such a way that an entire volume flow of a fluid supplied to the screw compressor for cooling and/or lubricating the engine bearing and the suction-side bearings flows through the compression chamber, with at least one suction-side bearing in particular not being sealed off from the compression chamber, preferably open. In particular, the volume flows through the engine mount and the two intake-side mounts flow into an intake-side end face of the compressor chamber. At least one (or all) of the volume flows through the motor bearing and/or the suction-side bearing can also open laterally into the compressor chamber, in particular if they are guided through ducts or lines outside the compressor housing, e.g. B. in hose lines. The entire volume flow of a fluid that is supplied to the screw compressor for cooling and/or lubricating the motor bearing, the suction-side bearings, in particular all bearings of the screw compressor, and the compressor rotors, i.e. the total volume flow of the fluid supplied through at least one fluid inlet, preferably flows through the compressor chamber . This achieves an integrated fluid circuit for cooling and/or lubricating the screw compressor, which can in particular be connected to or supplied by the same components of a compressor system.

In an advantageous development of the invention, the first supply line and/or the second supply line is each designed to conduct an auxiliary volume flow of a fluid for cooling and/or lubricating the engine bearing or the suction-side bearing, which is smaller than a main volume flow (total volume flow) of the Fluids, preferably at most 15%, more preferably at most 10%, of the main volume flow of the fluid, which during normal operation of the screw compressor is fed to the screw compressor, in particular to the at least one cooling channel for cooling the drive motor and/or to a fluid connection. The two secondary volume flows for cooling and/or lubricating the engine bearing and the suction-side bearing together amount to at most 25%, preferably at most 15%, of the total volume flow, which results from the sum of the two secondary volume flows and the main volume flow through the cooling ducts for cooling the drive motor. The secondary volume flows that are fed to the engine mount or the intake-side mounts can vary in size. In particular, the first and second feed lines have different cross sections, in particular different diameters, by means of which the auxiliary volume flow can be adjusted for a specific operating state of the screw compressor. Branch channels of the second supply line to each of the suction-side bearings can be designed differently, preferably with different cross-sections, in particular in order to supply the two suction-side bearings with a suitable volume flow for cooling and/or lubrication. In this way, the cooling and/or lubrication for the bearings can be individually optimized.

In an advantageous development of the invention, the screw compressor according to the invention comprises at least one bearing on the pressure side in order to rotatably support a compressor rotor in the housing, with at least one feed line from a pressure side, preferably a front face on the pressure side, of the compressor chamber to the bearing on the pressure side for a fluid for cooling and/or or lubrication of the pressure-side bearing and preferably a return line from the pressure-side bearing to the compression chamber is provided. The feed lines can run axially, ie parallel to the vertical axis or the axes of rotation of the compressor rotors. However, the feed lines can also run obliquely with respect to the vertical axis, preferably in the feed direction of the fluid from the outside in towards the bearing on the pressure side. The pressure-side bearings are preferably supported in a housing flange, which is connected to the compressor housing on the pressure side. In particular, if the compressor housing and a pressure-side housing flange are designed as an integral part, the pressure-side bearings can be supported in the compressor housing, in which case a suction-side housing flange would be provided in which the suction-side bearings are supported. In addition, the suction side and the pressure side could each have separate ones Housing flanges are flanged to the compressor housing, which then carry the respective bearings. In addition, the housing can be divided (in the middle), with a suction-side and a pressure-side housing flange preferably each being able to be formed integrally with one of the housing halves and thereby accommodating the bearings. Such supply lines can ensure adequate cooling and/or lubrication of the pressure-side bearing. The dimensioning of the supply line and the return line can be matched to the respective pressure-side bearing, which is then cooled and lubricated as required.

Furthermore, the stated object is achieved by a compressor system according to claim 15.

1. a) einen Schraubenverdichter, insbesondere ein zuvor beschriebener erfindungsgemäßer Schraubenverdichter, umfassend
   • ein Gehäuse, das eine Verdichterkammer und eine Motorkammer ausbildet,
   • ein Paar von ineinandergreifenden Verdichterrotoren mit Rotorwellen, wobei die Verdichterrotoren in der Verdichterkammer angeordnet sind und die Drehachsen der Rotorwellen parallel zueinander verlaufen,
   • ein Antriebsmotor, der in der Motorkammer angeordnet ist und eine Motorwelle zum Antrieb von mindestens einem der Verdichterrotoren aufweist,
     • wobei die Motorwelle und mindestens eine der Rotorwellen durch eine Durchgangsöffnung zwischen der Motorkammer und der Verdichterkammer miteinander gekoppelt sind,
     • wobei der Antriebsmotor und das Paar von Verdichterrotoren im normalen Betrieb des Schraubenverdichters übereinander, insbesondere vertikal übereinander, angeordnet sind,
   • saugseitige Lager, um die Verdichterrotoren drehbar im Gehäuse zu lagern,
   • mindestens ein Motorlager, um die Motorwelle endseitig drehbar im Gehäuse zu lagern; und
2. b) einen Fluidkreislauf aufweisend
   • einen ersten Kreislaufabschnitt zur Kühlung und/oder Schmierung des Motorlagers und
   • einen zweiten Kreislaufabschnitt zur Kühlung und/oder Schmierung mindestens eines der saugseitigen Lager,

dadurch gekennzeichnet, dass der erste Kreislaufabschnitt und der zweite Kreislaufabschnitt zueinander einer Parallelschaltung entsprechend ausgebildet sind.In particular, the object is achieved by a compressor system, in particular for generating compressed air, comprising:

1. a) a screw compressor, in particular a screw compressor according to the invention as described above, comprising
   • a housing forming a compressor chamber and a motor chamber,
   • a pair of intermeshing compressor rotors with rotor shafts, the compressor rotors being arranged in the compressor chamber and the axes of rotation of the rotor shafts being parallel to one another,
   • a drive motor which is arranged in the motor chamber and has a motor shaft for driving at least one of the compressor rotors,
     • wherein the motor shaft and at least one of the rotor shafts are coupled to each other through a through hole between the motor chamber and the compressor chamber,
     • wherein the drive motor and the pair of compressor rotors are arranged one above the other, in particular vertically one above the other, during normal operation of the screw compressor,
   • suction-side bearings to rotatably mount the compressor rotors in the housing,
   • at least one motor bearing for end-to-end rotatably supporting the motor shaft in the housing; and
2. b) having a fluid circuit
   • a first circuit section for cooling and/or lubricating the motor bearing and
   • a second circuit section for cooling and/or lubricating at least one of the suction-side bearings,

characterized in that the first circuit section and the second circuit section are designed to correspond to a parallel connection to one another.

In contrast to a series connection, connecting two circuit sections in parallel means that the same fluid stream does not flow in both circuit sections, since the total fluid stream of the fluid circuit is divided into two partial fluid streams. The two circuit sections are designed in accordance with a parallel connection in particular when the fluid circuit is divided or branched into a first circuit section, which runs through the engine mount, and a second circuit section, which runs through at least one (preferably both) of the suction-side mounts and both circuit sections unite again downstream or open into a common circuit section, in particular by opening into the compressor chamber. Such a parallel connection ensures that the same fluid stream does not flow through the engine mount and the intake-side mount in succession. A division of the circuit sections can take place inside or outside the housing of the screw compressor. For example, a division is achieved by separate fluid connections to an external fluid reservoir, in particular an oil separator, or a return line for separated fluid, for first and second feed lines, or by branching off first and second feed lines within the housing, for example from a cooling channel. The volumetric flows of the fluid in the first and the second circuit section can be selected differently, in particular tailored to the cooling and/or lubricating requirements of the bearing through which the flow occurs. A fluid flow through the cooling channels of a cooling jacket of the drive motor can be understood as a third circuit section which is connected in parallel to the first and second circuit sections, at least in the region of a circuit section which includes the injection line. The total volume flow of the fluid for cooling and/or lubricating the screw compressor is preferably conducted through the compressor chamber.

In particular, the first, second and third circuit sections open into the compression chamber. The advantages of a compressor system according to the invention are essentially the same as those already described above in connection with a screw compressor according to the invention.

The fluid circuit of the compressor system is designed in particular as an oil circuit and can include a primary separation and a secondary separation of oil from a generated compressed air flow, which are converted by a corresponding oil separator or oil filter. The oil separated in the primary separator (oil separator) is fed to the screw compressor according to the invention during normal operation for cooling and/or lubrication, in particular to the at least one cooling duct for cooling the drive motor and/or a first feed line for cooling and/or lubricating the motor bearing and/or a second supply line for cooling and/or lubricating at least one of the bearings on the suction side. The oil separated in the secondary separation (fine oil separator or oil filter, eg coalescence filter) is also returned to the screw compressor. In particular, the oil volume flow derived from the secondary separation is admixed at a suitable point to the oil volume flow from the primary separation (main oil volume flow). There are several options for connecting a suction line for oil from the secondary separation to the fluid circuit (oil circuit) of the compressor system. Firstly, the suction line can be connected to the injection line (main oil volume flow) before the resulting total oil volume flow enters the screw compressor. Second, the suction line can be added to the oil flow at or near the point of connection of the injection line (main oil flow) to the screw compressor. Third, the suction line can be connected to a cooling channel of the cooling jacket of the drive motor. Fourth, the suction line can be fed to the oil volume flow in a feed channel section between the exit of the oil from the cooling jacket of the drive motor and the injection of the oil into the compression chamber. This can be done at a position before an injection line branches into injection ports for the two compressor rotors, i.e. one injection port for the main rotor and one injection port for the slave rotor, or at a position after an injection line has branched into two injection ports, either on one of the two injection ports or on both injection ports. Fifth, the suction line can be connected to the compressor housing, so that the oil from the suction line directly into the compression chamber, namely in the suction area or at a point at another suitable pressure level in the compression chamber. Sixth, the suction line can be connected in the area of one of the bearing points, namely on the engine bearing, on a bearing on the suction side or on a bearing on the pressure side.

Furthermore, the stated object is achieved by a method for lubricating and/or cooling a screw compressor according to claim 16, which is also claimed.

• Zuführen eines Fluids zur Kühlung und/oder Schmierung eines Motorlagers einer Motorwelle eines Antriebsmotors des Schraubenverdichters über eine erste Zuführleitung;
• Zuführen eines Fluids zur Kühlung und/oder Schmierung mindestens eines saugseitigen Lagers einer Rotorwelle eines Verdichterrotors des Schraubenverdichters über eine zweite Zuführleitung;
• Abführen von Fluid von dem Motorlager in eine Verdichterkammer des Schraubenverdichters über eine Abführleitung, wobei in der Verdichterkammer ein Paar von ineinandergreifenden Verdichterrotoren angeordnet ist, deren Rotorwellen über saugseitige Lager drehbar im Gehäuse des Schraubenverdichters gelagert sind,

dadurch gekennzeichnet, dass das Fluid von dem Motorlager unter Umgehung der saugseitigen Lager, insbesondere über einen Lagerumgehungsabschnitt der Abführleitung, in die Verdichterkammer abgeführt wird.The disclosure of the invention includes in particular a method for lubricating and/or cooling a screw compressor, in particular a screw compressor according to the invention, preferably for generating compressed air, which includes the following steps:

• Supplying a fluid for cooling and/or lubricating a motor bearing of a motor shaft of a drive motor of the screw compressor via a first supply line;
• Supplying a fluid for cooling and/or lubricating at least one suction-side bearing of a rotor shaft of a compressor rotor of the screw compressor via a second supply line;
• Discharging fluid from the motor bearing into a compression chamber of the screw compressor via a discharge line, a pair of meshing compressor rotors being arranged in the compression chamber, the rotor shafts of which are rotatably mounted in the housing of the screw compressor via bearings on the suction side,

characterized in that the fluid is discharged from the motor bearing into the compression chamber, bypassing the suction-side bearing, in particular via a bearing bypass section of the discharge line.

The method has advantages similar to the screw compressor according to the invention and the compressor system according to the invention and can implement some or all of the procedural features described above.

In particular, in an embodiment of the method according to the invention, an entire volume flow of a fluid supplied to the screw compressor for cooling and/or lubricating the motor bearing and the suction-side bearings (62a, 62b) is conducted through the compression chamber, with at least one suction-side bearing in particular not being sealed off from the compression chamber, preferably open.

In particular, in an embodiment of the method according to the invention, a secondary volume flow of a fluid for cooling and/or lubricating the engine bearing or the suction-side bearing is supplied via the first feed line and/or the second feed line, which is smaller than a main volume flow (total volume flow) of the fluid, preferably at most 15%, more preferably at most 10%, of the main volume flow of the fluid that is supplied to the screw compressor during normal operation of the screw compressor, in particular to the at least one cooling channel for cooling the drive motor and/or a fluid connection.

Figur 1

eine schematische Darstellung einer Ausführungsform eines erfindungsgemäßen Schraubenverdichters in einer perspektivischen Ansicht;

Figur 2

eine schematische Darstellung der Ausführungsform eines erfindungsgemäßen Schraubenverdichters nach Figur 1 in einer Vorderansicht;

Figur 3

eine schematische Darstellung der Ausführungsform eines erfindungsgemäßen Schraubenverdichters nach Figur 1 in einer Seitenansicht;

Figur 4

eine schematische Darstellung der Ausführungsform eines erfindungsgemäßen Schraubenverdichters nach Figur 1 in einer Unteransicht;

Figur 5

eine schematische Darstellung der Ausführungsform eines erfindungsgemäßen Schraubenverdichters nach Figur 1 in einer geschnittenen Vorderansicht entlang der Linie A-A in Figur 3;

Figur 6

eine schematische Darstellung der Ausführungsform eines erfindungsgemäßen Schraubenverdichters nach Figur 1 in einer geschnittenen Seitenansicht entlang der Linie B-B in Figur 2;

Figur 7

eine schematische Darstellung der Ausführungsform eines erfindungsgemäßen Schraubenverdichters nach Figur 1 in einer geschnittenen Draufsicht entlang der Linie C-C in Figur 2;

Figur 8

eine schematische Darstellung einer zweiten Ausführungsform eines erfindungsgemäßen Schraubenverdichters in einer geschnittenen Vorderansicht, die der Ansicht gemäß Figur 5 entspricht;

Figur 9

ein schematisches Blockschaltbild einer Ausführungsform einer erfindungsgemäßen Kompressoranlage mit einem Fluidkreislauf zur Kühlung und/oder Schmierung;

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. Here show:

figure 1

a schematic representation of an embodiment of a screw compressor according to the invention in a perspective view;

figure 2

a schematic representation of the embodiment of a screw compressor according to the invention figure 1 in a front view;

figure 3

a schematic representation of the embodiment of a screw compressor according to the invention figure 1 in a side view;

figure 4

a schematic representation of the embodiment of a screw compressor according to the invention figure 1 in a bottom view;

figure 5

a schematic representation of the embodiment of a screw compressor according to the invention figure 1 in a sectional front view along the line AA in figure 3 ;

figure 6

a schematic representation of the embodiment of a screw compressor according to the invention figure 1 in a sectional side view along the line BB in figure 2 ;

figure 7

a schematic representation of the embodiment of a screw compressor according to the invention figure 1 in a sectional plan view along the line CC in figure 2 ;

figure 8

a schematic representation of a second embodiment of a screw compressor according to the invention in a sectional front view, according to the view figure 5 is equivalent to;

figure 9

a schematic block diagram of an embodiment of a compressor system according to the invention with a fluid circuit for cooling and / or lubrication;

In the following description of the invention, the same reference symbols are used for the same elements and those with the same effect.

The Figures 1 to 7 show a first embodiment of the screw compressor 1 according to the invention in different views. In the normal operating state, the screw compressor 1 is arranged in such a way that the longitudinal axis V runs in the vertical direction, ie in the direction of gravity, and the motor block 30 is arranged in the vertical direction above the compressor block 10 . The screw compressor 1 draws in a gaseous medium, such as air at ambient pressure or already pre-compressed air from a preceding compressor stage, through an intake opening 19 formed in an intake socket, which is discharged through an outlet opening 20 formed in an outlet socket as a compressed medium at a higher pressure level from the Screw compressor 1 is pushed out. The intake side of the screw compressor 1 is located here on the side of the compressor block 10 facing the engine block 30 , while the pressure side is located on the side facing away from the engine block 30 .

The screw compressor 1 comprises a housing 60 which comprises a motor housing 32 and a compressor housing 12 with a housing flange 17 which is closed off by a cover plate 18 . The motor housing 32 has a circular-cylindrical basic shape and comprises an upper housing part 33 and a lower housing part 34, between which a cooling jacket 39 is arranged or clamped. At the A cover member 38 is inserted at the top of the upper case 33 .

The parts of the housing 60 described are each connected to one another by screw connections, with the housing flange 17 and the compressor housing 12 being screwed to one another and the compressor housing 12 to the lower housing part 34 in each case via a flange connection. The housing 60 is made of a metallic material.

In figure 5 the screw compressor 1 is shown in a sectional view from the front. The housing 60 forms a motor chamber 31 and a compressor chamber 11 which are not sealed from one another here. A drive motor 40 is arranged in the motor chamber 31 and is designed here as an electric motor, for example as a synchronous motor. The drive motor 40 includes a stator 35 with coil windings and a rotor 36 with permanent magnets, which is fixed to the motor shaft 37 with the axis of rotation M in a rotationally fixed manner. In the compression chamber 11, a pair of meshing compressor rotors 13 and 14, which form a main rotor and a secondary rotor, are arranged with rotor shafts 15 and 16, the axes of rotation of which R1 and R2 are parallel to one another. The compressor rotors 13, 14 have helical gearing and mesh in such a way that, when rotating, they compress the gas flowing in through the suction opening 19, build up a pressure difference from the suction side to the pressure side within the compression chamber 11 and push the compressed gas through the outlet opening 20 push out The compressor rotor 14 is driven by the drive motor 40 with the axis of rotation R2 being coaxial with the axis of rotation M, both of which are also coincident with the longitudinal vertical axis V . The motor shaft 37 is directly and non-rotatably connected to the rotor shaft 16 by a shaft connection 22 . The shaft connection 22 is designed here as a cylindrical seat, with the screwed-in tie rod clamping the connected shafts together axially in addition to the primary connection mechanism. The rotor shaft 16 extends through a through-opening 21 between the compressor chamber 11 and the motor chamber 31, the through-opening 21, ie a gap between the rotor shaft 16 and the through-opening 21, not having to be sealed. Here the motor housing 32 and the compressor housing 12 are designed with separate intermediate housing walls, which are formed by the lower housing part 34 and a suction-side end wall of the compressor housing. The housing 60 can also be a have a common intermediate housing wall for the compressor chamber 11 and the motor chamber 31 .

The rotor shafts 16, 15 are mounted in the compressor housing 11 on both sides. On the pressure side, the pressure-side bearings 63a and 64a or 63b and 64b are supported in the housing flange 17, with a radial bearing 63a or 63b, e.g. a cylindrical roller bearing, and an axial bearing 64a or 64b, e.g. an angular ball bearing, being provided . On the suction side, the suction-side bearings 62a, 62b are supported in a front wall of the compressor housing 11, and they could also be supported in the lower housing part 34. Radial bearings, e.g. cylindrical roller bearings or needle bearings, are provided as suction-side bearings 62a, 62b, whereby the two suction-side bearings 62a and 62b can be designed differently in terms of bearing type and dimensioning, resulting in different requirements for lubrication and/or the cooling can result. The compressor rotors 13, 14 or the ends of the rotor shafts 15, 16 have different diameters and correspondingly different rotational speeds, which in turn can influence the need for lubrication and/or cooling. The motor shaft 37 is supported on one side, namely at the upper end, via the motor bearing 61 which is supported in the cover element 38 which is inserted into the upper housing part 33 . The motor bearing 61 is designed as a radial bearing, e.g. as a grooved ball bearing, with a seal 66, e.g. a labyrinth seal, being arranged underneath for sealing against the motor chamber 31.

The screw compressor 1 is designed here as a fluid-injected screw compressor, the fluid injected for cooling and/or lubrication preferably being oil. The screw compressor 1 has a fluid inlet 51, via which the screw compressor 1 can be connected to a fluid circuit 50 of a compressor system 100, in particular to a return line 4, which returns the recovered fluid, e.g. oil from an oil separator 2, to the fluid inlet 51 (see Fig figure 9 ). Inside the cooling jacket 39, cooling channels 52 extend in the direction of the axis of rotation M or the vertical axis V along the motor chamber 31 for cooling the drive motor 40. The cooling channels 52 are distributed uniformly over the circumference of the cooling jacket 39 as recesses in the shape of ring segments (see figure 7 ), a total of five cooling channels 52 being provided here. The cooling channels 52 are connected to one another in the circumferential direction via deflection channel sections (not shown). The The entire fluid flow (oil flow) is fed to a single cooling channel 52 (annular segment) and guided through the individual cooling channels 52 one after the other by deflection channel sections. Alternatively, a distribution channel can be formed in the circumferential direction on an upper side of the cooling channels 52 such that the fluid can flow from the fluid inlet 51 into the various cooling channels 52 . A collecting channel would then be formed in the circumferential direction on an underside of the cooling channels 52 . After the drive motor 40 has been cooled, the fluid is fed through an injection line 53 to the compressor chamber 11 and injected into it in order to cool and lubricate the compressor rotors 13, 14 and to cool the air to be compressed. A first supply line 54 branches off from a cooling duct 52 through a branch opening to the engine mount 61 in order to supply it with fluid for lubrication and/or cooling (in figure 6 ). The fluid is conducted through the cooling jacket 39 into the lower housing part 34 via a separate discharge line 55 . The discharge line 55 has a bearing bypass section 56 which bypasses the suction-side bearings 62a, 62b, ie leads past them in order to open into the compression chamber 11. The bearing bypass section 56 is designed here as a channel running in the housing 60, for example a bore. The bearing bypass section 56 extends from the lower housing part 34 into the compressor housing 12 via a pair of matching outlet and inlet openings, e.g. formed by bores, in a common interface 25 of the motor housing 32 and the compressor housing 12. The bearing bypass section 56, however, could also be formed by a pipe section, which could also run outside of the housing 60, for example between an underside of the lower housing part 34 and a side wall of the compressor housing 12, and is connected to a through hole in the compressor housing 12. Such a bearing bypass section 56 ensures that a fluid flow which has previously flowed through the motor bearing 61 does not also flow through the suction-side bearings 62a, 62b. This prevents a fluid that has already been preheated from only being able to provide a reduced cooling capacity for the suction-side bearing 62a, 62b. A second supply line 57 branches off from a cooling channel 52 through a branch opening to the suction-side bearings 62a, 62b, with the supply line 57 dividing into branch lines 57a and 57b, each of which supplies one of the two suction-side bearings 62a or 62b with a fluid flow for cooling and /or supply lubrication. The fluid flows through the suction-side bearings 62a, 62b, which then flows to a suction-side end face 23 into the compression chamber 11 exits. In this way, the total volume flow of the fluid supplied to the screw compressor 1 through the fluid inlet 51 is initially divided into two secondary volume flows, namely through the first supply line 54 and the second supply line 57 , and a main volume flow through the injection line 53 . Finally, the various fluid streams reunite insofar as they all pass through the bearing bypass section 56, the suction-side bearings 62a, 62b and the injection line 53 into the compression chamber 11 and mix there with the gas to be compressed. The secondary volume flows for cooling and/or lubricating the engine bearing 61 and the suction-side bearings 62a, 62b can be selected, for example via the diameter of the first supply line 54 and the second supply line 57, in such a way that an optimal or needs-based flow rate is achieved for the respective bearing Cooling and / or lubrication adjusts.

Supply lines 58a, 58b are provided for cooling and/or lubricating the pressure-side bearings 63a, 63b, 64a, 64b, which run away from a pressure-side end face 24 of the compression chamber 11 inwards at an angle to the pressure-side bearings 63a, 63b. Driven by the pressure difference, the fluid flow is fed back into the compression chamber via a common return line 59 .

In figure 8 a second embodiment of a screw compressor 1 according to the invention is shown, wherein instead of the branching off of the second feed line 57 from a cooling channel 52, a separate fluid connection 70 is provided, to which the second feed line 57 is connected. The feed line 57 runs horizontally approximately at the level of the suction-side bearing and is designed here as a channel in the lower housing part 34 . The second supply line 57 can be connected to an external fluid reservoir, for example a fluid collection container or an oil separator, via the fluid connection 70, for example via a branch line of the return line 4 (see figure 9 ). Incidentally, the in figure 8 described embodiment with the embodiment according to Figures 1 to 7 coincide, in particular with regard to the branch channels 57a and 57b. A separate fluid connection 70 has the advantage that the suction-side bearings 62a, 62b can be supplied with fresh fluid that has not already been preheated by the cooling of the drive motor 40 as it flows through the cooling jacket 39 in the cooling channels 52 . As a result, in particular the cooling effect for the suction-side bearings 62a, 62b can be improved.

Further embodiments are possible in which, instead of branching off the first feed line 54 from a cooling channel 52, a separate fluid connection is provided, preferably at the height of the engine mount 61, to which the first feed line 54 is connected. Alternatively, in one embodiment, a separate or a common fluid connection 70 can also be provided for both the first supply line 54 and the second supply line 57, with the fluid connection 51 for supplying the cooling channels 52 being provided independently of this.

In figure 9 a compressor system 100 according to the invention with a screw compressor 1 and a fluid circuit 50 is shown schematically. The fluid circuit 50 comprises an oil separator 2, a return line 4 for separated oil and an oil cooler 3, which may comprise a heat exchanger or a fan, for example. Compressed air and oil are routed from the outlet opening 20 into the oil separator 2 via an outlet line 6, where the oil is separated and kept in a collection tank of the oil separator 2 as an external fluid reservoir (oil reservoir) for return to the screw compressor 1. Compressed air can be taken from the oil separator 2 for use by a consumer via a valve-controlled outlet 5 . The fluid circuit 50 comprises a first circuit section 81 through the engine mount 61 and a second circuit section 82 through the suction-side mounts 62a, 62b, which are arranged in parallel with one another or are traversed parallel to one another. The injection line 53 can be viewed as a third circuit section 83 which is connected in parallel to the two circuit sections 81 , 82 , ie branches off from the second circuit section 82 . The first circuit section 81 comprises the first feed line 54 and the discharge line 55 with the storage bypass section 56. The second circuit section 82 comprises the second feed line 57 with the branch lines 57a, 57b. The third circuit section 83 includes the injection line 53. The fact that the circuit sections 81, 82 are provided according to the invention in the form of a parallel connection and not as a series connection ensures that the engine mount 61 and the suction-side mounts 62a, 62b are not successively flowed through by the same fluid flow . The resulting advantages correspond to those already Were explained in connection with a screw compressor 1 according to the invention.

• Zuführen eines Fluids zur Kühlung und/oder Schmierung eines Motorlagers (61) einer Motorwelle (37) eines Antriebsmotors (40) des Schraubenverdichters (1) über eine erste Zuführleitung (54);
• Zuführen eines Fluids zur Kühlung und/oder Schmierung mindestens eines saugseitigen Lagers (62a, 62b) einer Rotorwelle (15, 16) eines Verdichterrotors (13, 14) des Schraubenverdichters (1) über eine zweite Zuführleitung (57);
• Abführen von Fluid von dem Motorlager (61) in eine Verdichterkammer (11) des Schraubenverdichters (1) über eine Abführleitung (55), wobei in

der Verdichterkammer (11) ein Paar von ineinandergreifenden Verdichterrotoren (13, 14) angeordnet ist, deren Rotorwellen (15, 16) über saugseitige Lager (62a, 62b) drehbar im Gehäuse (60) des Schraubenverdichters (1) gelagert sind,
dadurch gekennzeichnet, dass das Fluid von dem Motorlager (61) unter Umgehung der saugseitigen Lager (62a, 62b), insbesondere über einen Lagerumgehungsabschnitt (56) der Abführleitung (55), in die Verdichterkammer (11) abgeführt wird.The lubrication and/or cooling of the screw compressor 1 works as follows:

• Supplying a fluid for cooling and/or lubricating a motor bearing (61) of a motor shaft (37) of a drive motor (40) of the screw compressor (1) via a first supply line (54);
• Supplying a fluid for cooling and/or lubricating at least one suction-side bearing (62a, 62b) of a rotor shaft (15, 16) of a compressor rotor (13, 14) of the screw compressor (1) via a second supply line (57);
• Discharging fluid from the engine mount (61) into a compression chamber (11) of the screw compressor (1) via a discharge line (55), wherein in

a pair of interlocking compressor rotors (13, 14) is arranged in the compressor chamber (11), the rotor shafts (15, 16) of which are rotatably mounted in the housing (60) of the screw compressor (1) via bearings (62a, 62b) on the suction side,
characterized in that the fluid is discharged from the motor bearing (61) into the compression chamber (11) bypassing the suction-side bearing (62a, 62b), in particular via a bearing bypass section (56) of the discharge line (55).

At this point it should be pointed out that all aspects of the invention described above, viewed individually and in any combination, in particular the details shown in the drawings, are claimed as essential to the invention. Modifications of this are familiar to those skilled in the art.

Reference List

1

screw compressor

2

oil separator

3

oil cooler

4

return line

5

outlet

6

outlet line

10

airend

11

compression chamber

12

compressor housing

13

compressor rotor

14

compressor rotor

15

rotor shaft

16

rotor shaft

17

housing flange

18

cover plate

19

intake port

20

exhaust port

21

passage opening

22

shaft connection

23

suction-side face

24

pressure-side face

25

interface

30

drive block

31

motor chamber

32

motor housing

33

Upper case part

34

Lower housing part

35

stator

36

rotor

37

motor shaft

38

cover element

39

cooling jacket

40

drive motor

50

fluid circuit

51

fluid inlet

52

cooling channel

53

injection line

54

supply line

55

discharge line

56

storage bypass section

57

supply line

57a, 57b

branch channels

58a, 58b

supply line

59

return line

60

Housing

61

engine mount

62a, 62b

suction-side bearing

63a, 63b

pressure-side radial bearing

64a, 64b

pressure-side thrust bearing

66

poetry

70

fluid connection

81

first part of the circuit

82

second part of the circuit

83

third part of the cycle

100

compressor system

V

longitudinal axis

R1, R2

axes of rotation

M

axis of rotation

Claims (16)

Screw compressor (1), in particular for generating compressed air, comprising: - a housing (60) forming a compressor chamber (11) and a motor chamber (31), - a pair of meshed compressor rotors (13, 14) with rotor shafts (15, 16), the compressor rotors (13, 14) being arranged in the compressor chamber (11) and the axes of rotation (R1, R2) of the rotor shafts (15, 16) run parallel to each other, - a drive motor (40) which is arranged in the motor chamber (31) and has a motor shaft (37) for driving at least one of the compressor rotors (13, 14), wherein the motor shaft (37) and at least one of the rotor shafts (15, 16) are coupled to one another through a through opening (21) between the motor chamber (31) and the compressor chamber (11), wherein the drive motor (40) and the pair of compressor rotors (13, 14) are arranged one above the other, in particular vertically one above the other, during normal operation of the screw compressor (1), - suction-side bearings (62a, 62b) to rotatably support the compressor rotors (13, 14) in the housing (60), - at least one motor bearing (61) to rotatably support the motor shaft (37) at the end in the housing (60), - a first supply line (54) for a fluid for cooling and/or lubricating the motor bearing (61), - a second supply line (57) for a fluid for cooling and/or lubricating at least one of the suction-side bearings (62a, 62b), - a discharge line (55) for the fluid from the engine mount (61) into the compressor chamber (11), characterized in that
the discharge line (55) has a bearing bypass section (56) which, bypassing the suction-side bearings (62a, 62b), opens into the compression chamber (11). Screw compressor according to claim 1,
characterized in that at least one cooling channel (52) is provided in the housing (60), in particular in a cooling jacket (39) of the drive motor (40), from which the first supply line (54) and/or the second supply line (57) branches off. Screw compressor according to claim 1 or 2,
characterized in that at least one fluid connection (70) is provided, via which the first supply line (54) and/or the second supply line (57) can be connected to a, preferably external, fluid reservoir, in particular an oil separator (2). Screw compressor according to claim 3,
characterized in that - the fluid connection (70) for the first supply line (54) is arranged at the level of the engine mount (61), in particular on the side of the housing (60), and/or - The fluid connection (70) for the second supply line (57) is arranged at the level of the suction-side bearing (62a, 62b), in particular on the side of the housing (60). Screw compressor according to one of the preceding claims,
characterized in that the second supply line (57) comprises branch channels (57a, 57b) to one of the suction-side bearings (62a, 62b). Screw compressor according to one of the preceding claims,
characterized in that the discharge line (55) is designed as a separate fluid line, which in particular runs at least in sections parallel to a cooling channel (52) of the drive motor (40), preferably inside the cooling jacket (39) of the drive motor (40). Screw compressor according to one of the preceding claims,
characterized in that the bearing bypass portion (56) is formed as a channel portion within the housing (60) extending particularly in the vertical direction. Screw compressor according to one of the preceding claims,
characterized in that the casing (60) comprises a compressor casing (12) and a motor casing (32) which are integral with one another, the suction-side bearing (62a, 62b) being supported in the compressor casing (12). Screw compressor according to one of the preceding claims,
characterized in that the bearing bypass section (56) is formed at least partially within the compressor housing (12), in particular as a through hole, preferably in a suction-side end face (23) of the compressor housing (12). Screw compressor according to one of the preceding claims,
characterized in that the bearing bypass section (56) opens into the compression chamber (11) on the suction side, in particular in a suction-side end face of the compression chamber (11). Screw compressor according to one of the preceding claims,
characterized in that the motor housing (32) and the compressor housing (12) have at least one pair of mutually matching outlet or inlet openings in a common boundary surface (25), through which the bearing bypass section (56) or a branch channel (57a, 57b) runs. Screw compressor according to one of the preceding claims,
characterized in that the screw compressor (1) is designed in such a way that an entire volume flow of a fluid supplied to the screw compressor (1) for cooling and/or lubricating the motor bearing (61) and the suction-side bearings (62a, 62b) flows through the compression chamber (11 ) flows, in particular at least one suction-side bearing (62a, 62b) is not sealed towards the compression chamber (11), preferably open. Screw compressor according to one of the preceding claims,
characterized in that the first supply line (54) and/or the second supply line (57) is each designed to supply a secondary volume flow of a fluid for cooling and/or lubricating the engine bearing (61) or the suction-side bearing (62a, 62b). conduct, which is smaller than a main volume flow of the fluid, preferably at most 15%, more preferably at most 10%, of the main volume flow of the fluid in normal operation of the screw compressor (1) the screw compressor (1), in particular the at least one cooling channel (52) for cooling the drive motor (40) and/or a fluid connection (70). Screw compressor according to one of the preceding claims,
characterized by at least one pressure-side bearing (63a, 63b, 64a, 64b) to rotatably support a compressor rotor (13, 14) in the housing (60), with at least one feed line (58a, 58b) from a pressure side, preferably a pressure-side end face (24), the compression chamber (11) to the pressure-side bearing (63a, 63b, 64a, 64b) for a fluid for cooling and/or lubricating the pressure-side bearing (63a, 63b, 64a, 64b) and preferably a return line (59) from the pressure-side bearing (63a, 63b, 64a, 64b) into the compression chamber (11). Compressor system (100), in particular for generating compressed air, comprising: c) a screw compressor (1), in particular according to one of claims 1 to 14, comprising - a housing (60) forming a compressor chamber (11) and a motor chamber (31), - a pair of meshed compressor rotors (13, 14) with rotor shafts (15, 16), the compressor rotors (13, 14) being arranged in the compressor chamber (11) and the axes of rotation (R1, R2) of the rotor shafts (15, 16) run parallel to each other, - a drive motor (40) which is arranged in the motor chamber (31) and has a motor shaft (37) for driving at least one of the compressor rotors (13, 14), wherein the motor shaft (37) and at least one of the rotor shafts (15, 16) are coupled to one another through a through opening (21) between the motor chamber (31) and the compressor chamber (11), wherein the drive motor (40) and the pair of compressor rotors (13, 14) are arranged one above the other, in particular vertically one above the other, during normal operation of the screw compressor (1), - suction-side bearings (62a, 62b) to rotatably support the compressor rotors (13, 14) in the housing (60), - At least one motor bearing (61) to support the end of the motor shaft (37) rotatably in the housing (60); and d) having a fluid circuit (50). - A first circuit section (81) for cooling and/or lubricating the motor bearing (61) and - a second circuit section (82) for cooling and/or lubricating at least one of the suction-side bearings (62a, 62b), characterized in that
the first circuit section (81) and the second circuit section (82) are designed to correspond to one another in parallel connection. Method for lubricating and/or cooling a screw compressor, in particular a screw compressor according to one of Claims 1 to 14, preferably for generating compressed air, which comprises the following steps: - Supplying a fluid for cooling and/or lubricating a motor bearing of a motor shaft of a drive motor of the screw compressor via a first supply line; - Supplying a fluid for cooling and/or lubricating at least one suction-side bearing of a rotor shaft of a compressor rotor of the screw compressor via a second supply line; - Discharge of fluid from the motor bearing in a compression chamber of the screw compressor via a discharge line, wherein in the A pair of interlocking compressor rotors is arranged in the compression chamber, the rotor shafts of which are rotatably mounted in the housing of the screw compressor via bearings on the suction side, dad u rch characterized in that the fluid is discharged from the motor bearing bypassing the suction-side bearings, in particular via a bearing bypass section of the discharge line, into the compression chamber.

Images