Subrack and module assembly comprising the subrack

A subrack including a frame defining a subrack space and adapted to receive a device module to an operative position, the frame comprising four side walls and an end wall. The subrack comprises a coupling system adapted for coupling the subrack to four other subracks in order to form a subrack matrix, the coupling system comprising at least one wall recess on an inner surface of each of the side walls, and at least one primary screw hole in each of the side walls such that the at least one primary screw hole is located in the at least one wall recess.

FIELD OF THE INVENTION

The present invention relates to a subrack for receiving a device module, and to a module assembly comprising said subrack and a device module adapted to be received in the subrack.

BACKGROUND OF THE INVENTION

A known electrical assembly comprises an electrical cabinet and a plurality of device modules received in the electrical cabinet. Each of the device modules comprises an electrical device such as a frequency converter, and a device module connector system. The electrical cabinet comprises a cabinet connector system adapted to be in electrically conducting connection with the device module connector system. The device modules are installed to the electrical cabinet by pushing them into their operative positions relative to the electrical cabinet.

One of the problems associated with the above known electrical assembly is that if a location of the cabinet connector system differs from its intended location, pushing a device module into the electrical cabinet might damage the cabinet connector system and/or the device module connector system. Said problem is in some cases caused by a fact that an electrical cabinet of an electrical assembly is assembled by a supplier different than the one supplying device modules for the electrical assembly.

BRIEF DESCRIPTION OF THE INVENTION

An object of the present invention is to provide a subrack and a module assembly comprising the subrack so as to solve the above problem. The objects of the invention are achieved by a subrack described in the following.

The invention is based on the idea of providing a subrack, which is adapted to receive a device module, with a subrack connector system and a coupling system, wherein the subrack connector system is adapted to be in electrically conducting connection with a device module connector system of the device module, and the coupling system is adapted for coupling the subrack to four other subracks in order to form a subrack matrix. The coupling system allows coupling the subrack to an adjacent subrack or to an electrical cabinet by screws installed from inside the subrack.

An advantage of the subrack of the invention is that a connector system adapted to co-operate with a device module connector system is always correctly aligned with the device module connector system since the subrack is provided with a subrack connector system. Since the subrack of the invention allows forming subrack matrixes of unlimited sizes, an electrical cabinet can be furnished with a required number of device modules such that each of the device modules is received in a corresponding subrack.

DETAILED DESCRIPTION OF THE INVENTION

FIG.1shows a subrack501comprising a frame4, a subrack connector system52, a bus bar system, and a coupling system adapted for coupling the subrack501to four other identical subracks501in order to form a subrack matrix. The frame4comprises four side walls41-44and an end wall45such that the side walls41-44and the end wall45together define a subrack space55. The frame4is adapted to receive a device module to an operative position in which the device module is located in the subrack space55. The frame4is depicted as a transparent structure in order to better show components inside the frame4.

Side wall41is parallel to and spaced apart from side wall42. Side wall43is parallel to and spaced apart from side wall44. Side walls43and44are perpendicular to side walls41and42. Side walls43and44connect side walls41and42together. Side walls41and42are longer than side walls43and44. End wall45is perpendicular to the side walls41-44.

FIG.2shows a module assembly comprising the subrack501ofFIG.1, and a device module201in a disconnected position relative to the subrack501. The device module201is adapted to be connected in a connecting event to the operative position relative to the subrack501. During the connecting event, a relative movement between the device module201and the subrack501is linear, and parallel to a depth direction of the subrack501. The frame4of the subrack501and the device module201are depicted as transparent structures in order to better show components inside them.FIG.3shows the module assembly ofFIG.2in a situation where the device module201is in the operative position relative to the subrack501.

The device module201comprises an electrical device (not depicted), and a device module connector system22. In an embodiment the electrical device of the device module comprises a frequency converter. In another embodiment the electrical device of the device module comprises an LCL filter.

The subrack connector system52is adapted to be in electrically conducting connection with the device module connector system22of the device module201while the device module201is in the operative position. The subrack connector system52comprises a plurality of subrack connectors527fastened to the end wall45such that the plurality of subrack connectors527is accessible from the subrack space55.

The coupling system comprises wall recesses14on an inner surface of each of the side walls41-44, and a plurality of primary screw holes71in each of the side walls41-44such that each of the plurality of primary screw holes71is located in one of the wall recesses14. Each of the wall recesses14is adapted to accommodate screw heads91of screws9mounted to primary screw holes71located in the wall recess14, and extending outwards from the wall recess14through the primary screw holes71such that the subrack space55is adapted to receive the device module201to the operative position while there is a corresponding screw9mounted in each of the primary screw holes71. Due to the wall recesses14, the device module201in the operative position is not in contact with the screws9mounted in the primary screw holes71.

InFIGS.1and2, some of the primary screw holes71are provided with screws9while others are empty. The screws9are self-tapping screws. In an embodiment, only one screw per side wall is required for coupling the subrack to four other sub racks.

In addition to the plurality of primary screw holes71, the coupling system comprises a plurality of secondary screw holes72in each of the side walls41-44such that each of the plurality of secondary screw holes72is located in one of the wall recesses14. Each of the wall recesses14is adapted to accommodate screw tips92of screws9mounted to secondary screw holes72located in the wall recess14, and extending inwards to the wall recess14through the secondary screw holes72such that the subrack space55is adapted to receive the device module201to the operative position while there is a corresponding screw9mounted in each of the secondary screw holes72.

The screw head91of the screw9is adapted to be engaged by a tool for turning the screw9. The screw tip92of the screw9is located at an opposite end of the screw9than the screw head91. A diameter of the screw head91is larger than a diameter of the screw tip92.

The primary screw holes71and the secondary screw holes72are unthreaded holes, and diameters of the secondary screw holes72are smaller than diameters of the primary screw holes71. The primary screw holes71and the secondary screw holes72are located asymmetrically in the frame4such that when the subrack501is coupled to four adjacent subracks with the coupling system, each primary screw hole71of the subrack501is adjacent to and coaxial with a secondary screw hole of one of the adjacent subracks. The self-tapping screws form threads at least to the secondary screw holes72.

In an alternative embodiment the coupling system comprises only primary screw holes and no secondary screw holes, and the primary screw holes are threaded holes. In said embodiments screws do not have to be self-tapping screws.

FIG.4shows the subrack501from a direction perpendicular to the end wall45of the frame of the subrack. Depth of the wall recesses14is best seen inFIG.4.FIG.5shows the subrack501from a direction parallel to the end wall45of the frame of the subrack.

The bus bar system has five bus bars81-85, and is electrically conductively connected to the subrack connector system52. The bus bar system is accessible from outside the frame4.

Each of the bus bars81-85is formed from sheet metal. Bus bars83and84are one-piece components, and bus bars81,82and85each comprises two bent pieces of sheet metal.

Each of the bus bars81-85has a bus bar terminal comprising a terminal hole800whose centre axis extends perpendicular to a plane defined by the end wall45. The bus bar terminal are denoted with reference numbers819-859. Each of the terminal holes800is a threaded hole. There is a space for a cable terminal adjacent each of the terminal holes800such that each of the bus bar terminals819-859is adapted to be electrically conductively connected to a cable terminal of a corresponding cable extending outside the subrack501. A cable terminal is adapted to be connected to a corresponding bus bar terminal by a bolt screwed to a terminal hole of the bus bar terminal.

In an alternative embodiment terminal holes are unthreaded holes. In a further alternative embodiment, terminal holes in sheet metal material of the bus bars are unthreaded holes but there is a nut connected adjacent to each of the terminal holes such that a thread of the nut is coaxial with the terminal hole.

The subrack connector system52is adapted to enable connecting the device module201into the operative position simply by pushing the device module201into the subrack space55, wherein said pushing establishes the electrically conducting connection between the subrack connector system52and the device module connector system22. Device module connectors227of the device module connector system22are knife contacts, and subrack connectors527are adapted to receive the knife contacts.

The subrack space55has generally a shape of a rectangular parallelepiped, and the device module201has generally a shape of a rectangular parallelepiped such that when the device module201is in the operative position relative to the subrack501, outer surfaces of side walls of the device module201are adjacent inner surfaces of side walls41-44of the frame4of the subrack501thereby assuring a correct alignment between the device module connector system22and the subrack connector system52. In an alternative embodiment outer surfaces of at least three side walls of the device module are in contact with adjacent at least three inner surfaces of side walls of the frame of the subrack thereby assuring a correct alignment between the device module connector system and the subrack connector system.

FIG.6shows a subrack matrix150comprising nine subracks501coupled together by means of the coupling systems thereof. The subrack in the middle of the subrack matrix150is coupled to four other subracks by means of the coupling system such that the subrack in the middle is coupled to subracks adjacent to the four side walls. Planes defined by end walls of the subracks501in the subrack matrix150coincide with each other.

FIG.7shows a module assembly comprising the subrack matrix150ofFIG.6and nine device modules201received in the subrack matrix150. Planes defined by front walls of the device modules201coincide with each other.

In an embodiment, the module assembly ofFIG.7is mounted in an electrical cabinet (not depicted). In said embodiment, the subrack matrix150is located inside the electrical cabinet, and is coupled to the electrical cabinet with the coupling systems of the subracks501in the subrack matrix150. In an alternative embodiment, the subrack matrix functions as an independent support structure, and no electrical cabinet is required.

FIG.8illustrates coupling of three subracks501together by means of coupling systems of the subracks501. Sidewall42of a subrack on the left is adapted to be adjacent to sidewall41of a subrack in the middle. Sidewall44of the subrack in the middle is adapted to be adjacent to sidewall43of a subrack below. When the three subracks are coupled together, primary screw holes71in side wall42of the subrack on the left are adjacent to and coaxial with secondary screw holes72in side wall41of the subrack in the middle. Further, primary screw holes71in side wall44of the subrack in the middle are adjacent to and coaxial with secondary screw holes72in side wall43of the subrack below.

It will be obvious to a person skilled in the art that the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.