TW202413802A - Housing for housing a gearbox of a rotary screw compressor - Google Patents

Abstract

According to an embodiment, the invention comprises a beam-shaped housing (100) for housing a system for transmitting a torque from a drive shaft of a motor to rotor shafts of a rotary screw compressor, the housing (100) comprising a motor opening (104) on a first side (102), and two screw openings (202, 203) on a second side (200) opposite and parallel to the first side (102), characterized in that the housing (100) further comprises two sets of ribs (204, 205) extending between the first (102) and second (200) side, and wherein ends of the ribs (204, 205) on the second side (200) are radially distributed per set about the screw openings (202, 203), and wherein the ends of the ribs (204, 205) on the first side (102) converge per set to a point (206, 207) of the edge of the motor opening (104).

Description

Housing for housing the gearbox of a rotary screw compressor

The present invention relates to a housing for housing a mechanical system, such as a gearbox, for transmitting a mechanical torque from a motor to one or more shafts of a rotary screw compressor.

A rotary screw compressor is a machine designed to produce compressed gases such as compressed air. The compressed gas at a specific operating pressure is then used in a variety of applications such as powering other machines.

A rotary screw compressor includes a twin screw as a male and female rotor, which rotate in opposite directions as the volume between them and the housing decreases. Each screw has a helical shape, and as the rotors rotate, gas is compressed between the rotors.

In order to rotate the rotors, a drive consisting of an electric motor, a power turbine, a diesel engine, or any other suitable drive is required. However, the speed at which the screw of the rotary screw compressor must rotate to achieve a desired working pressure is usually not comparable to the speed of the drive. Nevertheless, even if the speeds are matched, the mechanical torque from the drive still needs to be transmitted to the screws.

To transmit the mechanical torque, a mechanical system configured to transmit the mechanical torque is used. The mechanical system is, for example, a set of gears that mechanically connects the shaft of the rotor of the drive machine.

For reasons of safety and stability, the mechanical system must be protected on the one hand and the mechanical system together with the drive shaft and rotor of the rotary screw compressor must be stably supported on the other hand.

Accordingly, there is a need for a housing that safely, stably and permanently houses a mechanical system for transmitting a mechanical torque from a drive engine to a rotary screw compressor.

An object of the present invention is to provide a housing for housing a mechanical system for transmitting a mechanical torque from a drive engine to a rotary screw compressor.

This object is achieved according to a first aspect of the present invention by providing a shell as claimed in claim 1.

The present invention comprises a generally beam-shaped housing for housing a mechanical system configured to transmit a mechanical torque from a drive shaft of a motor to a first and/or second screw shaft of a rotary screw compressor, the housing comprising a motor opening on a first side, and two screw openings on a second side opposite and parallel to the first side, the motor opening being adapted for insertion of the drive shaft, the two screw openings being adapted for insertion of the drive shaft, The openings are each suitable for inserting the first and second screw shafts, respectively, and are characterized in that the housing further includes a first and second set of ribs extending between the first and second sides, respectively, and the ends of each set of ribs on the second side are radially distributed around the first and second screw openings, respectively, and the ends of each set of ribs on the first side converge toward a first or second point on the edge of the motor opening, respectively.

It will be appreciated that the housing is generally beam-shaped. A geometric beam or rectangular block is a polyhedron having six rectangular faces, eight corners, and twelve edges also referred to as ribs. The generally beam-shaped shape of the housing means that one or more corners and/or edges may be fully or partially rounded. Furthermore, there may also be one or more notches and/or protrusions. Thus, there may be deviations from the exact shape of a geometric beam, wherein those skilled in the art clearly recognize that the outer surface of the housing is beam-shaped.

The drive shaft originates from a drive engine of an electric motor, a power turbine, a diesel engine, or any other engine suitable for this purpose. The drive shaft of the drive engine is inserted into the housing on a certain side of the housing, the first side, further referred to as the motor side. On the side opposite to the motor, the second side, the two shafts of the rotor or screw of the rotary screw compressor are arranged. This side is further referred to as the compressor side.

Generally speaking, the drive shaft will not be axial with one of the screw shafts. Rather, the screw shafts are axially parallel to each other, as is usually the case with a rotary screw compressor. Furthermore, for a highly efficient mechanical transmission, the axes of the drive shaft and screw shaft will be perpendicular to a plane determined by the motor side and/or the compressor side. As a result, the axes do have the same direction.

A motor opening is provided for the insertion of the drive shaft, while a plurality of screw openings are provided for the screw shafts. The housing thus has a plurality of openings on two opposite sides. Furthermore, the housing will be partially hollowed out to accommodate the mechanical system.

The housing further features a novel concept of including two sets of internal ribs for housing rigidity and strength for a highly efficient torque transfer. Hereinafter, it will be further explained how these sets of ribs are constructed.

The ribs are generally made of the same material as the rest of the shell. Alternatively, the ribs may be made of a different material if they can be fixedly bonded to the material forming the shell.

Each set of ribs extends between the first and second sides, in other words between the motor side on the one hand and the compressor side on the other hand.

The ribs are generally elongated in the direction between the aforementioned sides, wherein the cross section is generally rectangular. The ends of each group of the ribs are radially distributed around the periphery of the two screw openings. In other words, the ends of the ribs of the first group are radially distributed around the periphery of the first screw opening, and the ends of the ribs of the second group are radially distributed around the periphery of the second screw opening.

Each set of ribs thus extends to the side of the motor, with the ends of each set meeting or converging to each respective point adjacent the edge of the opening.

Through the aforementioned architecture, several advantages over previous technologies can be found.

By distributing the ends of the ribs radially around the respective screw openings, vibrations caused by the rotating screw during operation are compensated and/or absorbed by the ribs without force concentration at a single point. In other words, vibrations that are exposed around the screws and distributed around the screws are absorbed by the ribs.

When the components in the housing operate, and therefore when the mechanical torque from the drive motor is transferred to the screws via the drive shaft, most of the vibrations will originate from the rotating screws. This can be explained by comparing the operation of a compressor to that of a drive motor. Since ambient air or other gases are compressed in a compressor, it is more dependent on external factors that can affect operation, while a drive motor can operate more stably than a compressor. However, please note that this depends on the drive technology used. An electric motor will generally operate more stably than an internal combustion engine.

On the motor side, the ends of each set of ribs converge to a point. Vibrations from the rotating screws can therefore be concentrated per screw at a point around the motor opening. This allows reinforcement on the motor side to make the area at and around these points strong, rigid and/or sturdy enough to absorb these vibrations.

Another advantage is that this structure keeps the ribs from contacting the rotating components located in the housing. The ribs can therefore be positioned so that they do not interfere with the operation of the mechanical transmission system.

Preferably, the ribs do not have sharp transitions. This has the advantage that no additional stress concentrations will occur.

According to one embodiment, the point at which the ends of the first and second sets of ribs converge lies in a plane defined by the geometric axes of the screw shafts when installed or placed in the screw holes.

In other words, the points on the edge of the motor opening where the ribs converge for absorbing vibrations are located in a plane that is perpendicular to the plane of the motor side and further defined by the geometric axis or diameter of the screw shafts when installed in the screw holes. As a result, vibrations occurring in the axial direction of the screw shafts can be absorbed efficiently without causing imbalance again through the ribs. If these points are not located in the aforementioned plane, a mechanical momentum will occur between these points and the points located on the geometric axis of the screw shafts, and this imbalance may occur.

According to one embodiment, the cross-section of the ribs gradually increases from the first to the second side.

Therefore, according to the present embodiment, the cross section of the ribs will increase from the edge of the motor opening or a point on the edge of the motor opening to a point around the periphery of the screw openings. Since the vibrations are concentrated at these points, this creates sufficient strength on the side where the maximum vibrations will occur, as explained above.

Preferably, according to one embodiment, an edge of one or more ribs in the longitudinal direction between the two ends will be further joined on at least one side different from the motor side and/or the compressor side, preferably two other sides.

The ribs are respectively engaged on the inner side of the housing, where the motor is arranged, and on the side where the compressor is located, or at least on the side where the drive shaft or the screw shafts are located. Since the housing is mostly rectangular in shape, at least four further sides can be distinguished on the inner side. The ribs will therefore preferably also be engaged on one or two further inner sides. Engagement means that the ribs are fixedly connected with an edge and become one piece, for example by a casting process or a welding technique. As a result, the vibrations are even better distributed throughout the housing.

Furthermore, according to one embodiment, the housing may further include a third set of straight ribs extending on the side of the motor opening or between the motor side and the side of the screw openings or the compressor side and on the other hand in a direction of a side plane that is perpendicular to the plane of the motor side or the compressor side. These ribs thus further provide sufficient strength in a direction perpendicular to the plane defined by the geometric axes of the screw shafts.

In addition to this, the housing may further comprise a fourth set of ribs extending between the motor side and the compressor side and perpendicularly to the ribs of the third set. This thus provides even further additional strength in this direction, thereby ensuring in combination with the other third set of ribs sufficient strength in every orthogonal direction of the housing. This allows efficient transmission of mechanical torque from the motor to the screw of the compressor.

Finally, the ends of the ribs of the third and/or fourth group can be joined to the edge of the motor opening. As a result, the ribs extend over the entire permissible length to obtain the maximum rigidity of the housing.

According to one embodiment, the second side, and therefore the compressor side, further comprises a second motor opening for supporting the drive shaft. In other words, the drive shaft extends along two outer sides of the housing so that the drive shaft is supported on the compressor side. As a result, bending of the drive shaft in one axial direction is accommodated and thereby prevented or at least reduced.

Furthermore, preferably according to one embodiment, the motor opening on the first side is suitable for the insertion of a shield or housing of the motor. In other words, the motor opening on the motor side is large enough to surround the housing of the motor. This allows the motor to be tightened against the housing.

According to one embodiment, the screw openings are preferably adapted to be inserted into a shroud or housing of the rotary screw compressor. This also allows the compressor to be permanently attached to the housing for housing the mechanical system. An impedance system can thus be installed together with the motor opening housing the motor shroud, allowing the transmission of the mechanical torque to be carried out efficiently.

According to a second aspect of the present invention, a substantially beam-shaped housing for accommodating a mechanical system according to the first aspect of the present invention is disclosed, wherein the housing is obtained by a permanent molding technique and/or a subtractive molding technique.

The housing thus consists of a single piece consisting of cast steel or cast iron, moulded into the desired shape, as has been described above.

According to a third aspect, a compressor unit is disclosed, comprising a motor and a rotary screw compressor, and further comprising a housing according to the first aspect of the present invention, the mechanical system being used to transmit a mechanical torque from a drive shaft of the motor to a first and/or second screw shaft of the rotary screw compressor.

The present invention will be described with reference to certain specific embodiments and with reference to certain specific drawings, but the present invention is not limited thereto and is defined only by the scope of the patent application. The drawings described are only illustrative and non-limiting. In the drawings, the size of certain specific elements may be exaggerated for illustrative purposes and not drawn to scale. The dimensions or relative dimensions do not necessarily correspond to actual feasible embodiments of the present invention.

In addition, the terms first, second, third and the like are used in the specification and in the claims to distinguish similar elements and do not necessarily describe a sequential or chronological order. These terms are interchangeable where appropriate, and embodiments of the present invention may be used in an order other than that described or illustrated herein.

In addition, the terms top, bottom, above, below, and the like in the specification and patent application are used for illustrative purposes and do not necessarily describe relative positions. The terms so used are interchangeable where appropriate, and the embodiments of the invention described herein may be used in orientations other than those described or illustrated herein.

Furthermore, although referred to as "preferred embodiments", the various embodiments are understood to be examples of implementing the invention rather than limitations on the scope of the invention.

The term "comprising" used in the scope of the application should not be understood as being limited to the means or steps described below; the term does not exclude other elements or steps. The term should be interpreted as indicating the presence of the mentioned enumerated features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components, or groups thereof. The scope of the phrase "a device comprising means A and B" should therefore not be limited to a device consisting only of components A and B. The meaning is that, for the purposes of the present invention, only components A and B of the device are listed, and the scope of the application is further interpreted to include equivalents of these components.

The housing shown in the drawings is a housing for housing a mechanical system for transmitting a mechanical torque from a drive shaft of a motor to a rotary screw compressor.

FIG. 1 is a view of the motor side 102 of a housing 100 according to an embodiment of the present invention. The housing 100 is mostly beam-shaped, wherein one or more corners may be rounded, such as corner 101. On the motor side 102 of the housing 100, there is a motor opening 104 in the form of a circle 103, suitable for accommodating a drive shaft together with a shield of the motor.

Through the motor opening 104, there is a view of the inside of the housing, which is discussed in the subsequent figures.

FIG. 2 illustrates the same housing 100, but from the view of the compressor side 200. On this side 200, there is also an opening 201 for supporting the drive shaft of the motor. The opening 201 can also be seen in FIG. 1 through the motor opening 104. Both openings 104, 201 are formed by a circle 103, wherein the center of the motor opening 104 coincides with the center of the opening 201 for the drive shaft. In other words, when the circles forming the openings 104, 201 are projected onto each other, their respective centers coincide.

On the compressor side 200 as shown in Figure 2, two openings 202, 203 are further shown which are arranged to connect and receive the screw of a rotary screw compressor. The shape of these openings 202, 203 is not circular, but is adapted to the special shape of a rotary screw compressor and is particularly adapted to the screw of the rotary screw compressor.

Through these openings 202, 203, ribs 205 and 204 can be seen, respectively, each set 205, 204 emanating from the compressor side 200 and converging to a respective point 207 and 206 on the motor side 102. The points 206 and 207 are then located on the edge 103 of the motor opening 104. In other words, the ribs 204, 205 extend between the motor side 102 and the compressor side 200, wherein on the compressor side 200, the ends are located on the edge of the respective openings 202 and 203 and converge towards the points 207 and 206, respectively.

The set of ribs 205, 204 is further illustrated in Figure 4, which shows a view of the inner side of the motor side 102 of the housing 100. This view corresponds to the section IV-IV of Figure 3, which shows a side view of the housing 100.

As can be further seen in FIG. 3 , a protrusion 301 is provided at the opening 201 for the drive shaft to support the drive shaft.

FIG. 5 also illustrates the inside, but from a relative view, i.e. looking towards the compressor side 200, therefore according to the section V-V as shown in FIG. 3 .

As can be seen in Figure 4, the ribs 204, 205 are engaged on the side at points 206, 207 on the edge of the motor opening 104. In other words, each set of ribs 204, 205 is engaged on a common point 206, 207 on the edge of the motor opening 104.

On the other hand, as shown in Fig. 5, the ends are distributed on the edges of the screw holes 202 and 203. For the rib set illustrated by reference numeral 204, it is joined at points 503-505, and for the rib set illustrated by reference numeral 205, it is joined at points 500-502.

Furthermore, the housing 100 may comprise a set of straight ribs inside, extending in a direction between the motor side 102 and the compressor side 200 on the one hand and according to a side of the housing 100 on the other hand. This is illustrated by the ribs 400-404 in both Figures 4 and 5. Furthermore, perpendicular to these straight ribs 400-404, a fourth set of ribs illustrated by the ribs 510-511 in Figures 4 and 5 may be provided.

According to one embodiment, the vertical direction of this straight rib may be partially offset from that illustrated by rib 404. Again, additional ribs may be provided to strengthen the housing, but it will be further understood that these additional ribs are optional and in the case of rib sets 204 and 205 provide efficient mechanical torque transmission from the drive shaft of the motor of the rotary screw compressor to one of the first and/or second screw shafts in accordance with the novel aspects of the present invention.

Finally, Figures 6 and 7 illustrate three-dimensional side views of the housing 100, looking towards the compressor side 200 and the motor side 102, respectively. On the compressor side 200, the point 207 to which the ribs 205 converge can be seen through the screw opening. Further, the ribs 204 extending between the compressor side 200 and the motor side 102 can be seen. And, once again, the opening 201 for supporting the drive shaft of the motor is illustrated. In Figure 7, this opening 201 is also illustrated, this time from a view of the motor side 102.

100: Housing 101: Corner 102: Motor side 103: Circle 104: Motor opening 200: Compressor side 201: Second motor opening 202-203: Screw hole 204: First set of ribs 205: Second set of ribs 206: First point 207: Second point 301: Protrusion 400-404: Third set of straight ribs 500-505: End 510-511: Fourth set of straight ribs

The present invention will be further illustrated with reference to the drawings, wherein: FIG. 1 illustrates a front view of the motor side according to one embodiment of the present invention; FIG. 2 illustrates a front view of the compressor side according to one embodiment of the present invention; FIG. 3 illustrates a side view of the housing according to one embodiment of the present invention; FIG. 4 illustrates a view of the inner side of the motor side of the housing according to one embodiment of the present invention; FIG. 5 illustrates a view of the inner side of the compressor side of the housing according to one embodiment of the present invention; FIG. 6 illustrates a three-dimensional side view of the compressor side according to one embodiment of the present invention; and FIG. 7 illustrates a three-dimensional side view of the motor side according to one embodiment of the present invention

200: Compressor side

201: The second motor opens

204: The first set of ribs

207: Second point

Claims (12)

A beam-shaped housing (100) configured to accommodate a mechanical system, the mechanical system being configured to transmit a mechanical torque from a drive shaft of a motor to a first and/or second screw shaft of a rotary screw compressor, the housing (100) comprising a motor opening (104) on a first side (102), and two screw openings (202, 203) on a second side (200) opposite to and parallel to the first side (102), the motor opening being adapted for insertion of the drive shaft, the two screw openings (202, 203) being adapted for insertion of the first and second screw shafts, respectively, Its characteristics are that The housing (100) further includes a first (204) and a second (205) set of ribs extending between the first (102) and second (200) sides, respectively, and the ends of the ribs of each set (204, 205) on the second side (200) are radially distributed around the first (500-502) and second (503-505) screw openings, respectively, and the ends of the ribs of each set on the first side converge to a first (206) and a second (207) point on the edge of the motor opening (104), respectively. A housing (100) as claimed in claim 1, wherein the points (206, 207) at which the ends of the ribs of the first (204) and second (205) groups respectively converge are located in a plane defined by the geometric axes of the screw shafts when attached. A shell (100) as claimed in any one of claims 1 to 2, wherein the cross-section of the ribs (204, 205) gradually increases from the first side (102) to the second side (200). A shell (100) as claimed in any one of claims 1 to 3, wherein an edge of a rib along the longitudinal direction between the two ends is joined to at least one side different from the first (102) or second (200) side. A shell (100) as claimed in any one of claims 1 to 4, further comprising a third set of straight ribs (400-404) extending between the first (102) and second (200) sides on the one hand and in a direction along a side of the substantially beam-shaped shell (100) on the other hand, the direction being perpendicular to a plane defined by the first (102) or second (200) side. The shell (100) of claim 5 further comprises a fourth set of straight ribs (510-511) extending between the first (101) and second (200) sides on the one hand and in a direction perpendicular to the direction of the third set (400-404) on the other hand. A housing (100) as claimed in claim 6, wherein the ends of one or more ribs of the third (400-404) and/or fourth (510-511) groups are joined to a point on the edge of the motor opening (104). A housing (100) as claimed in any one of claims 1 to 7, further comprising a second motor opening (201) on the second side (200) adapted to support the drive shaft. A housing (100) as claimed in any one of claims 1 to 8, wherein the motor opening (104) on the first side (102) is further suitable for inserting a shield of the motor. A housing (100) as claimed in any one of claims 1 to 9, wherein the screw openings (202, 203) are further suitable for inserting a shield of the rotary screw compressor. A substantially beam-shaped housing (100) for accommodating a mechanical system as claimed in any one of claims 1 to 10 is obtained by a permanent molding technique and/or a subtractive molding technique. A compressor unit comprises a motor and a rotary screw compressor, and further comprises a housing (100) as in any one of claims 1 to 11, configured to transmit a mechanical torque from a drive shaft of the motor to a first and/or second screw shaft of the rotary screw compressor.