DE102018204322B4 - Machine axis arrangement, rotary-swivel unit and method for transmitting electrical energy and information by means of a machine axis arrangement - Google Patents

Abstract

Machine axis arrangement (80), with a shaft (84) rotatable about a rotation axis (R); and an inner and an outer rotary transformer assembly (100, 98), each comprising an inner element (106, 116) and an outer element (102, 114) that are rotatable relative to one another and are designed to cooperate to transmit information and/or electrical energy; wherein one of the inner element (106, 116) and outer element (102, 114) of a respective rotary transformer assembly (100, 98) is coupled to the shaft (84); andwherein a diameter of the outer rotary transformer assembly (98) is larger than a diameter of the inner rotary transformer assembly (100),characterized in thatthe machine axis arrangement (80) comprises a first line arrangement (112) for providing an electrical energy supply and a second line arrangement (115) for transmitting information and no or at most less electrical energy than is transmitted by means of the first line arrangement (112), wherein the first line arrangement (112) is connected to one of the inner and outer rotary transformer assemblies (100, 98) and the second line arrangement (115) is connected to the corresponding other rotary transformer assembly (100, 98).

Description

The invention relates to a machine axis arrangement, a rotary-swivel unit and a method for transmitting electrical energy and information by means of a machine axis arrangement. In particular, the invention relates to the arrangement of a plurality of rotary transmitter assemblies in a machine axis arrangement and/or in a rotary-swivel unit. The machine axis arrangement and/or the rotary-swivel unit can preferably be used in a coordinate measuring machine.

Coordinate measuring machines are used in a generally known way to record the coordinates of an object surface tactilely or without contact. To do this, a sensor unit, e.g. in the form of a tactile measuring probe or a non-contact scanning optical sensor, is moved relative to an object to be measured in order to record several measuring points on the object surface along a predetermined movement path, for example. The measurement information can be in the form of so-called 3D point clouds or 3D coordinate clouds and can generally be used to determine properties of the object, such as its dimensional accuracy.

In coordinate measuring machines, but also in numerous other machines with controllable axes, which are also covered by the invention, so-called rotary-swivel units are often used, which comprise machine axis arrangements with rotating shafts and in particular rotating output shafts or drive shafts. Units coupled to these can be rotated in the desired manner via the shaft. For example, the machine axis arrangement can provide a rotary axis of a rotary-swivel unit and rotate a swivel axis coupled to this via its shaft.

In such machine axis arrangements, information and/or electrical energy (for example in the form of an electrical load or power) often have to be transmitted to a unit coupled to the shaft and, in particular, rotating together with it. The use of so-called cable windings or winding springs is known for this purpose, in which a section of a cable coupled to the shaft is unwound and wound up from a generally stationary drum in accordance with the rotation of the shaft. Disadvantages of this solution are the maximum angle of rotation limited by the length of the cable, the relatively high installation space requirement, the limited number of cables within the cable and the limited available cable cross-section.

As an alternative, so-called rotary transformer assemblies can be considered, which generally enable electrical or optical energy, signal and/or information transmission between a rotating axis and an axis or a fixed area that is fixed relative to it. In particular, they typically offer the advantage of enabling endless rotation of a shaft relative to a fixed area of the machine axis arrangement. Endless rotation can be understood as free or unrestricted rotation that can be a multiple of 360°.

Rotary joint assemblies can be designed in the form of slip ring assemblies (in particular in the form of mechanical and/or contact-based slip rings), as used, for example, in the EN 10 2014 118 359 A1 In this case, a generally rotating annular element can comprise electrically conductive sections or tracks which are in electrically conductive contact with contact elements of another and generally stationary element of the assembly.

There are also optical rotary joints (also known colloquially as optical slip rings or, more precisely, as fiber optic rotary joints). In this case, a light guide and a light coupler are usually moved past each other using elements that can be rotated relative to each other under a signal coupling. For example, the light guide can describe a circular path and the light coupler can travel the inside of this circular path using a circular movement. An example of this can be found in the DE 102 56 634 A1 , wherein one of the elements rotatable relative to one another is partially accommodated in the corresponding other and/or wherein the elements rotatable relative to one another generally have different diameters. The invention is directed in particular to optical rotary transformers according to this or comparable designs.

Furthermore, according to the invention, rotary transformer assemblies of known design can also be used, which are designed for capacitive or inductive signal and/or energy transmission.

In general, rotary joint assemblies can therefore comprise an inner and outer element that can rotate relative to one another and interact with one another to transmit information, signals and/or energy. One of the elements can, for example, rotate together with the shaft, while the other is fixed within the machine axis arrangement. Due to the transmission between the inner and outer element, a (e.g. electrical) A signal (electrical or optical) and/or energy (preferably electrical) can be transmitted from a fixed region of the machine axis arrangement to a component rotating together with the shaft.

Rotary joint assemblies according to any of the above variants can also be used within the scope of the invention. Unless otherwise stated or apparent, all statements on rotary joint assemblies can primarily refer to slip ring assemblies and specifically to mechanical and/or contact-based slip ring assemblies.

As described, in the case of slip ring assemblies, one of the inner and outer elements typically has a plurality of ring-shaped electrically conductive tracks when viewed along the axis of rotation. The other of the inner and outer elements has contact elements that can be brought into electrically conductive contact with these tracks. The individual tracks can be galvanically applied to carrier bodies. Alternatively, the tracks can be provided by arranging individual ring elements on a carrier body (for example by sliding the ring elements on). The individual ring elements are preferably separated from one another by electrically insulating rings.

The galvanic application of the conductor tracks makes it possible to provide a comparatively high track density (also known as a small pitch). However, this manufacturing process is relatively expensive. Furthermore, sufficient electrical insulation and/or shielding between adjacent tracks cannot always be guaranteed. This can lead to short circuits between adjacent tracks due to abrasion (for example in the form of gold chips), which can result in significant malfunctions.

On the other hand, using a plurality of ring elements can reduce manufacturing costs, but the installation space required by the rotary joint assembly increases compared to electroplated slip rings. This primarily affects an axial installation space along the axis of rotation. However, particularly in the field of measurement technology and especially with coordinate measuring machines, it is preferable to keep the installation space of machine axis arrangements small. To be more precise, a measuring space within which the measurement of an object can be carried out should not be unnecessarily taken up by the coordinate measuring machine itself or its machine axis arrangements.

However, a space-saving configuration is generally only possible in the variant with multiple ring elements if the transmission capabilities of the slip rings are reduced (e.g. in the form of a reduced number of individual tracks, a reduced number of transmittable signals, a reduced transmission rate and/or a reduced transmission quality (e.g. by reducing signal quality)). The minimum achievable slip ring width is also limited by the fact that connecting lines and/or cables must still be able to be connected to the ring elements and, for example, soldered to them. The insulator elements between the individual ring elements cannot be designed with an arbitrarily small width, which also contributes to a limitation of the minimum achievable pitch (i.e. the minimum distance between individual conductor tracks) and thus the minimum achievable axial length of the slip ring.

Optical rotary joints also have problems with regard to installation space, as individual fiber optic light coupler pairs often have to be provided for each signal to be transmitted. In a similar way to slip ring assemblies with a plurality of ring elements, this can be accompanied by a considerable increase in axial installation space.

The inventors also identified difficulties especially when a large number of individual signal and/or power transmissions are to be provided by means of a slip ring assembly (i.e. when the slip ring assembly is to serve as a connecting link for a large number of signal and/or power lines). In this case, it is necessary to select the diameter of an inner element of the slip ring assembly to be sufficiently large in order to be able to lead all the required signal lines and/or cables through and connect them to the inner element. The desired number of transmissions (or transmission paths) thus defines a minimum diameter of the inner element. On the other hand, a large diameter of the inner element can contribute to a reduction in the transmission capabilities, for example because the capacity of the individual conductor tracks increases with the increasing diameter. This creates a conflict of objectives with regard to a desired high number of transmission paths (i.e. a preferably high diameter) and the desired high transmission capabilities (i.e. a preferably small diameter).

In summary, it is not possible with the previous solutions to provide a space-saving energy and/or signal transmission using a machine axis arrangement that is characterized by low costs and, above all, preferably also allows for endless rotation and has high transmission capabilities. In particular, the inventors have recognized the conflict described regarding the small diameter required for transmission capability and the high diameter required for the number of transmission paths.

The generic US 4 335 927 A discloses a rotary transformer assembly with conductor rings that are concentrically accommodated in one another and work together to transmit energy. Further technological background can be found in US 2005 / 0 095 877 A1.

The EN 10 2016 203 762 A1 relates to a slip ring transformer for the electrical connection of assemblies of rotary machines and a rotary machine with the slip ring transformer.

An object of the present invention is therefore to enable a space-saving and cost-effective energy and/or signal transmission for a machine axis arrangement. In particular, this should be possible for a continuously rotating machine axis arrangement and preferably take place with the highest possible transmission capabilities.

This object is achieved by a machine axis arrangement, a rotary-swivel unit and a method according to the attached independent claims. Advantageous further developments are specified in the dependent claims. Furthermore, it is understood that the features mentioned in the introductory description can also be provided individually or in any combination in the solution disclosed here, unless otherwise stated or apparent.

The invention generally provides for a plurality of preferably smaller rotary transformer assemblies to be provided instead of a single rotary transformer assembly, which may be characterized by high manufacturing costs and/or a large installation space requirement. These are arranged in a space-saving manner, in particular in such a way that they are arranged in different radial areas with respect to the rotation axis of the shaft and are optionally also at least partially accommodated in one another.

In general, this can reduce the required installation space and, in particular, the required axial installation space. This can be achieved even if the rotary joint assemblies are not manufactured using galvanic manufacturing processes, but require cost-effective, but possibly less space-efficient manufacturing variants, such as the arrangement of separate ring elements on a carrier body described at the beginning.

A further advantage arises from the fact that a rotary transformer assembly with a relatively small diameter can be provided, which is characterized by high transmission capabilities due to the limited diameter (for example due to small capacitances of the individual conductor tracks and/or the high transmission frequencies made possible as explained below). This can be used to transmit signals with high bandwidths, transmission rates and/or a generally high signal quality. However, the invention makes it possible to provide an additional rotary transformer assembly with a relatively large diameter, so that a sufficiently large number of transmission paths are provided overall. If, on the other hand, only one rotary transformer assembly were to be provided and all lines and/or cables were to be connected to it, the conflict of objectives explained above with regard to a required minimum diameter would arise, which, however, does not always allow the desired transmission capabilities to be achieved.

In detail, a machine axis arrangement is proposed, with a shaft rotatable about a rotation axis, and an inner and an outer rotary transformer assembly, each comprising an inner element and an outer element that are rotatable relative to one another and are configured to cooperate for the transmission of information and/or electrical energy (e.g. in the form of electrical loads or power) (e.g. a general transmission via the rotary transformer assembly and/or a transmission between the elements); wherein one of the inner element and outer element of a respective rotary transformer assembly is coupled to the shaft; and wherein a diameter of the outer rotary transformer assembly is larger than a diameter of the inner rotary transformer assembly.

The machine axis arrangement can further comprise a drive unit, in particular in the form of an electric motor, to rotate the shaft. Alternatively or additionally, the machine axis arrangement can comprise a housing arrangement in which the shaft and/or the rotary transmitter assemblies are at least partially accommodated. In general, the machine axis arrangement can be designed to transmit a torque by means of the shaft to another component coupled thereto (for example a pivot axis of a rotary pivot unit).

The machine axis arrangement can generally be an electrically driven, electrically drivable and/or electrically controllable assembly or machine axis. The shaft can be coupled to a component that is to be driven in rotation. This can in particular be another machine axis or machine axis arrangement.

As explained in more detail below, the machine axis arrangement can provide a continuously rotating axis. In particular, it can provide a continuously rotating axis in a rotary-swivel unit in a continuously rotating measuring table. In general, the machine axis arrangement can be used or usable in a coordinate measuring machine, for example in a rotary-swivel unit or a measuring table of a coordinate measuring machine. Alternatively, the machine axis arrangement can be used in a robot, for example in a multi-axis industrial robot (for example in the form of a conventional articulated arm robot).

Unless otherwise stated or apparent, the terms axial and radial in the present disclosure refer to the axis of rotation about which the shaft is rotatable.

The shaft can comprise a first end region and a second end region which is opposite one another when viewed along the axis of rotation and which are connected via a connecting section. The first end region can be at least partially accommodated or receivable in a housing arrangement of the machine axis arrangement. Additionally or alternatively, the connecting section can interact with at least one of the rotary transmitter assemblies and/or be coupled to an element thereof. The second end region, on the other hand, can be coupled to a component which is to be driven in rotation by the shaft. This component can generally be a swivel axis or B-axis of a rotary-swivel unit. Additionally or alternatively, the rotationally driven component can comprise a measuring head or a measuring sensor or generally enable the acquisition of measurement signals and in particular object coordinates.

The shaft can be coupled in a rotationally fixed manner to a component of an optional drive of the machine axis arrangement that rotates about the rotation axis. If the drive comprises an electric motor or is implemented as such, the shaft can be coupled in a rotationally fixed manner to a rotor or runner of the electric motor or to a gear driven thereby.

As described in the introduction, the rotary joint assembly can be a slip ring assembly and/or an optical rotary joint assembly. In particular, it can be a mechanical and/or contact-based slip ring assembly.

The inner rotary transformer assembly can be a rotary transformer assembly that is radially inner (i.e. located radially further inside than the outer rotary transformer assembly) in relation to the axis of rotation. The outer rotary transformer assembly can be a rotary transformer assembly that is radially outer (i.e. located radially further outside than the inner rotary transformer assembly) in relation to the axis of rotation.

The inner and outer rotary transformer assemblies can generally be spaced apart from one another and in particular radially spaced apart from one another. Furthermore, these assemblies generally cannot contact one another. According to the invention, however, it is also possible for the rotary transformer assemblies to mechanically contact one another and/or to support one another. Optionally, the rotary transformer assemblies can also be designed to be at least partially connected and/or to have common components. For example, an inner element of the outer rotary transformer assembly and an outer element of the inner rotary transformer assembly can be coupled to one another or formed in one piece.

At least one of the inner element and outer element can each be provided in an annular shape or as a ring. Consequently, they can also be referred to as inner ring or outer ring. At least one region of the outer element facing the inner element and an outer region of the inner element facing the outer element can be designed in an annular shape or, in other words, as circular cylinder jacket surfaces. According to one variant, the inner element of the inner rotary transformer assembly is designed with a cross-section that is closed at least in places and, for example, as a shaft or is arranged on a shaft with a cross-section that is closed at least in sections.

The inner and outer elements of any rotary transformer assembly can generally have different diameters. In particular, a respective inner element can be at least partially accommodated in the outer element. Furthermore, it can generally be provided that a transmission area or a transmission surface of each rotary transformer assembly, via which or in which the information, electrical signals and/or electrical energies to be transmitted (for For example, loads or power) are transmitted, lie outside the axis of rotation of the shaft or do not intersect with it. In particular, the respective transmission regions or transmission surfaces (which can also be referred to as contact circles) can be essentially ring-shaped or describe a circular cylinder surface and further preferably extend concentrically around and along the axis of rotation. The transmission region or the transmission surface can generally be defined by a surface of the inner or outer element or can comprise such a surface which comprises electrically conductive tracks or a circular light guide. In particular, the transmission region can comprise a contact region in which contact elements and electrical conductor tracks of a conventional slip ring assembly are in contact with one another in a manner known per se.

As described, the respective inner element and the outer element preferably comprise two regions facing each other, at least one of which is implemented as a circular cylinder surface. As explained below, at least one of the regions can be defined by contact elements or comprise them, with this region only optionally being defined as a circular cylinder surface or comprising such a surface.

When the inner element and the outer element are rotated relative to one another, which generally preferably takes place about the axis of rotation of the shaft, the regions of these elements facing one another can also be rotated relative to one another accordingly. In particular, these regions are also rotated about the axis of rotation and/or moved past one another. According to a preferred variant, at least one of the inner element and outer element is arranged substantially stationary within the machine axis arrangement, while the other is rotatable relative thereto about the axis of rotation of the shaft. In this variant, a region (or a surface) of the rotatable element can thus be rotated or moved past the region of the fixed element facing it.

At least one of the inner element and the outer element can comprise electrically conductive tracks, with specific or, in other words, individual signals and/or electrical energies (or electrical loads or electrical power) being transmittable for each track. The other element of the inner element and the outer element can comprise contact elements in order to be electrically conductively connected to these tracks. The tracks can generally be ring-shaped and preferably extend along the entire circumference of the inner element or outer element. The contact elements, however, can only extend along a limited circumferential section of the inner element and/or outer element. The contact elements can generally comprise wires, wire brackets, wire brushes, metal pins, electrically conductive projections, graphite blocks, graphite pins or the like.

Preferably, electrically conductive tracks and in particular ring-shaped tracks are provided on only one of the inner and outer elements, with contact elements being provided on the other and preferably exclusively on the other of the inner and outer elements. According to conventional designations, the element of the inner and outer element that comprises the contact elements can be referred to as a stator. The element of the inner and outer element that comprises the conductor tracks, on the other hand, can be referred to as a rotor. In the context of the present disclosure, however, the terms stator and rotor are not necessarily to be understood in such a way that they also indicate any fixedness or mobility of the corresponding elements (i.e., an element that is to be referred to as a stator according to the above definition can in principle also be movable within the scope of the present disclosure and, for example, can be rotated relative to a fixed element that is to be referred to as a rotor according to the above definition).

In one embodiment, the inner element of the outer rotary transformer assembly comprises a plurality of electrically conductive ring-shaped sections (or tracks) and the outer element of the outer rotary transformer assembly comprises contact elements that are or can be brought into electrically conductive contact with the ring-shaped sections of the outer element. Additionally or alternatively, the inner element of the inner rotary transformer assembly can comprise a plurality of electrically conductive ring-shaped sections (or tracks) and the outer element of the inner rotary transformer assembly can comprise contact elements that are or can be brought into electrically conductive contact with the ring-shaped sections of the inner element. This arrangement makes it possible to achieve space-saving and assembly-friendly cable routing in the machine axis arrangement.

The diameter of the outer and/or inner rotary joint assembly can be a largest outer diameter, a smallest inner diameter or a mean diameter. The latter can be defined, for example, by an electrical contact or transmission area (or a contact path) or an optical transmission area between the inner and Outer element of the respective rotary transformer assembly. In particular, the diameter of the outer rotary transformer assembly can be defined by a (preferably smallest) diameter of its inner element and/or a diameter of the inner rotary transformer assembly can be defined by a (preferably largest) diameter of its outer element. All of the above and also the following diameters can be measured in a plane that runs perpendicular to the axis of rotation.

In order to achieve the diameter ratio described, a diameter (and in particular inner diameter) of the inner element of the outer rotary transformer assembly can be larger than a diameter (and in particular outer diameter) of the outer element of the inner rotary transformer assembly. The diameter of the inner element of the outer rotary transformer assembly can be the diameter of an area that faces away from the outer element of this rotary transformer assembly. It can also be the diameter of an inner surface of the inner element of the outer rotary transformer assembly that is coupled to the shaft, for example, for fastening the inner element.

The diameter of the outer element of the inner rotary joint assembly may be the diameter of a region facing away from the inner element of this rotary joint assembly. It may also be the diameter of an outer surface of the outer element that is coupled to and/or abuts the shaft.

It is understood that a diameter of the outer element of the outer rotary transformer assembly preferably exceeds the diameter and in particular the largest diameter of the inner element of this rotary transformer assembly. Likewise, a diameter of the inner element of the inner rotary transformer assembly preferably falls short of the diameter of the outer element of the inner rotary transformer assembly and in particular the smallest diameter of the outer element of the inner rotary transformer assembly. In other words, the inner elements of the rotary transformer assembly can preferably each be accommodated in the respective outer elements and/or axially displaced therein.

According to one embodiment of the device and the method, the rotary transformer assemblies are at least partially arranged along a common region of the rotation axis and/or extend along a common region of the rotation axis. In other words, the rotary transformer assemblies can overlap when viewed along the rotation axis. In this variant, at least one region can be defined along the rotation axis that is spanned by both the inner and the outer rotary transformer assemblies and/or that is accommodated in both of these rotary transformer assemblies. Figuratively speaking, the inner and outer rotary transformer assemblies can thus be axially pushed into one another and/or nested within one another within the machine axis arrangement. This helps to reduce the installation space and in particular an axial installation space of the machine axis arrangement.

In a further development of the arrangement and the method, the inner element of the outer rotary transformer assembly and/or the outer element of the inner rotary transformer assembly is coupled to the shaft for joint rotation. In particular, the inner element of the outer rotary transformer assembly can be arranged on an outer surface (e.g. in the form of an outer diameter step) of the shaft or can be supported thereon. The outer element of the inner rotary transformer assembly, on the other hand, can be arranged on an inner surface and in particular an inner diameter step of the shaft or can be supported thereon. The torque transmission can be achieved in particular by the corresponding elements of the rotary transformer assemblies being fixed relative to the shaft and in particular being mechanically coupled or fastened thereto directly or indirectly (for example by means of driver structures or a screw connection). At a higher level, the torque transmission can take place in such a way that the inner element and/or the outer element rotate together with the shaft, but cannot be rotated relative to it.

The respective other element of the outer rotary transformer assembly and/or the inner rotary transformer assembly, however, cannot be attached to the shaft or coupled to rotate together with it. In particular, they cannot be rotatable together with the shaft and are preferably fixed relative thereto or generally arranged fixed within the machine axis arrangement. In detail, the outer element of the outer rotary transformer assembly and/or the inner element of the inner rotary transformer assembly cannot be coupled to the shaft for rotation together.

The above-described specifications and rotatability of the individual elements of the inner and outer rotary joint assembly can each contribute to a space-saving configuration of the machine axis arrangement.

Any of the inner and outer elements of the inner and outer rotary joint assembly can extend, at least in sections, substantially concentrically along the axis of rotation of the shaft. This particularly applies to the inner element of the inner rotary joint assembly. The latter can be designed as a pin, cylinder, shaft, projection or rotary bearing for the shaft or can serve as such. Alternatively, the inner element can be designed substantially annularly and/or as a hollow cylinder and can be arranged on one of the aforementioned elements (for example a pin) or can accommodate a corresponding element.

In a further development of the device and the method, the shaft has a recess which extends at least in sections along the axis of rotation and in which the inner rotary transformer assembly is at least partially accommodated. Preferably, the recess also extends at least in sections essentially concentrically to the axis of rotation. The recess can accommodate the axis of rotation at least in sections or enclose the axis of rotation at least in sections. The recess can form a hollow shaft section of the shaft or be enclosed by such a hollow shaft section. In one variant, the shaft is designed as a hollow shaft. In this case, the recess can extend axially continuously through the shaft and along and preferably concentrically to the axis of rotation, for example in the form of a central through-hole. In other words, the shaft can be realized as a hollow shaft due to the recess.

An outer element of the inner rotary joint assembly can be coupled to and/or fastened to a recess according to any of the above variants. In particular, this can be done by abutting and/or fastening the outer element to an inner wall of the recess, which is preferably cylindrical or defines a cylinder surface (in particular a circular cylinder surface).

As described, the outer element of the outer rotary transformer assembly can also be arranged on an inner wall region of a housing arrangement of the machine axis arrangement. This can provide a desired alignment of the outer element and in particular concentricity thereof around the axis of rotation. For example, the inner wall region can provide a diameter fit. For axial fixing, a flat surface of the outer element can be screwed to a flange, for example. In general, the housing arrangement can at least partially accommodate and/or enclose an optional drive unit of the machine axis arrangement and/or the shaft.

The described arrangement options for the outer rotary joint assembly in a housing arrangement and the inner rotary joint assembly in a recess can each help to reduce the overall installation space required.

According to the invention, the machine axis arrangement comprises a first line arrangement (or, in other words, a first line strand) for providing an electrical energy supply and a second line arrangement (or, in other words, a second line strand) for transmitting information and no or at most less electrical energy than is transmitted by means of the first line arrangement. The first line arrangement is connected to one of the inner and outer rotary transformer assemblies and the second line arrangement is connected to the corresponding other of the inner and outer rotary transformer assemblies (and preferably to the inner one). The difference between the electrical energy transmitted can correspond to a factor of ten or a factor of five (for example in relation to the transmitted currents and/or maximum current intensities). Connecting the line arrangement to the respective rotary transformer assembly can be understood to mean a connection that transmits or conducts energy or information. In this embodiment, the transmitted information (for example in the form of electrical, digital or analog signals or data) and the transmitted electrical energy (for example in the form of electrical loads, electrical power or electrical currents) can thus be at least partially divided between the inner and outer rotary transformer assembly. At least the information transmission can take place according to a CAT5, CAT5e or preferably CAT6 standard.

In order to provide the electrical energy supply, the first line arrangement can be used to transmit, in particular, an electrical power or load that can be used to drive drive units of another component that is coupled to the shaft. Additionally or alternatively, the provision of the electrical energy supply can include the provision of a voltage supply. At a higher level, the electrical energy supply can include an electrical power transmission and/or electrical load transmission.

The information transmitted by means of the second line arrangement can comprise analog signals, digital signals or optical signals, whereby the latter can also be converted into electrical signals before transmission. The analog signals can be analog electrical signals, for example from measuring systems (for example in the form of a sensor device of a coordinate measuring machine) or analog identifiers. The identifiers can be provided in the form of an analog signal and can be used, for example, to identify units that are only indirectly or directly connected to the machine axis arrangement as required (for example to identify a sensor that is connected to an exchange interface). The identifiers can also simply indicate the presence of any unit of a predetermined type (for example a sensor) without identifying it in more detail. The digital signals can be digital electrical signals that are generated and/or transmitted, for example, in accordance with standardized transmission protocols such as Ethernet or CAN bus.

Generally speaking, the electrical energy supply can thus provide or include that electrical work can be performed using the transmitted electrical energy. The information transmission, on the other hand, can include that information can be generated, read out and/or evaluated using the transmitted signals.

It is understood that within the scope of the present disclosure, any of the above variants for energy supply or information transmission can also be provided even if the explained division of the corresponding transmissions to the inner and outer rotary transformer assemblies by means of separate line arrangements is not provided.

By at least partially dividing the energy supply and information transmission between different rotary transformer assemblies, it is possible to ensure that these transmissions do not influence each other or only influence each other to a reduced extent. In particular, information transmitted by means of one of the rotary transformer assemblies cannot be distorted or can only be distorted to a lesser extent by any electrical currents, voltages or power transmitted as part of the energy supply.

Preferably, the electrical energy supply is primarily via the outer rotary transformer assembly and the information is primarily transmitted via the inner rotary transformer assembly. In principle, however, it can be provided that both the outer and the inner rotary transformer assembly can transmit electrical energy and/or information. This is advantageous in that the outer rotary transformer assembly, due to its larger diameter, enables energy to be transmitted via connecting lines and/or conductor tracks with a generally larger cross-section. This is advantageous, for example, with regard to the amount of electrical energy that can be transmitted and/or heat resistance.

The (primary) transmission of information using the smaller-diameter inner rotary transformer assembly can, however, be advantageous in that it can reduce distorting influences on the information. Such influences can arise, for example, from the fact that the conductor tracks of the rotary transformer assembly behave in the sense of an electrical capacitance and can generate a distorting electrical field. Such capacitances are reduced by the smaller diameters of the inner rotary transformer assembly. In addition, the inventors have recognized that with smaller diameters, the requirements (for example in terms of a clock frequency and/or bandwidth) of current transmission standards can be met more easily.

It was also recognized that smaller diameters of the rotary transformer assemblies enable higher transmission frequencies, e.g. because their electrically relevant length is smaller in relation to the wavelength of the frequency to be transmitted. This applies in particular if the wavelength of the frequency to be transmitted is in the order of magnitude of the rotary transformer assembly or, more precisely, in the order of magnitude of the circumference of a signal ring (and/or a conductor track) plus associated contact elements of the rotary transformer assembly, since propagation processes known from high-frequency technology can then negatively influence the signal to be transmitted. Significant influences are to be expected, particularly for relevant lengths of greater than or equal to wavelength/4 (i.e. greater than or equal to a quarter of the wavelength). It is therefore preferable to keep the extent of structures that potentially interfere with the signal (e.g. the conductor track circumference) smaller than 5% to 10% of the wavelength.

A CAT6 data channel, for example, is specified for an operating frequency of up to 250 MHz. The wavelength depends on the relative dielectric constant and at 250 MHz corresponds to approximately 800 mm. The circumference of a signal track (and/or a conductor track) with a diameter of 70 mm corresponds to approximately 250 mm and would therefore be unfavorable for a CAT6 data channel from a high-frequency point of view.

Instead, according to the invention, four-pair impedance-controlled CAT6 cables with a diameter of 6 mm, for example, can be connected via the inner rotary transformer assembly. Including the supporting structure, this results in a diameter of 8 mm, for example, for the signal tracks or conductor paths, which corresponds to a ring circumference of approx. 25 mm and would therefore be less than 5% of the wavelength. A mechanically more robust variant has a diameter of 20 mm and a signal track or conductor track circumference of 63 mm, for example.

The inventors have therefore recognized that due to these properties and the lower crosstalk due to the low capacities already mentioned above for fast data transmissions (e.g. according to current standards), a small diameter of the rotary transformer assembly and in particular of the inner rotary transformer assembly is preferable.

A further development of the machine axis arrangement and the method provides that at least one of the inner and outer rotary transformer assemblies (and preferably at least the inner one) is set up for signal transmission with a bandwidth of at least 100 MHz (and preferably at least 200 MHz, e.g. at least 250 MHz or even more) and/or a transmission rate of at least 1 gigabit/s. Additionally or alternatively, the signal transmission can take place according to a predetermined transmission protocol (e.g. Ethernet).

The invention further relates to a rotary-swivel unit, in particular for use in a coordinate measuring machine, comprising a machine axis arrangement according to one of the preceding claims. The machine axis arrangement can in particular provide a rotary and/or swivel axis of the rotary-swivel unit or be comprised of such. According to a variant, the machine axis arrangement provides a rotary axis of such a unit and in particular an endlessly rotating rotary axis. The rotary axis can also rotate a swivel axis of the rotary-swivel unit, wherein the swivel axis is preferably not designed as an endlessly rotating axis, but rather as an axis that rotates only to a limited extent.

• - Übertragen von elektrischer Energie (und/oder einer elektrischen Last und/oder einer elektrischen Leistung) mittels einer ersten von der inneren und äußeren Drehübertragerbaugruppe; und
• - Übertragen von Informationen mittels der entsprechenden anderen Drehübertragerbaugruppe sowie keiner oder allenfalls einer geringeren elektrischen Energie, als über die erste Drehübertragerbaugruppe übertragen wird.

The invention further relates to a method for transmitting energy and information by means of a machine axis arrangement, wherein the machine axis arrangement is designed according to any of the preceding or following aspects and the method comprises:

• - transmitting electrical energy (and/or an electrical load and/or an electrical power) by means of a first of the inner and outer rotary joint assemblies; and
• - Transmission of information by means of the corresponding other rotary transformer assembly and no or at most less electrical energy than is transmitted via the first rotary transformer assembly.

As described above, this can be made possible in particular by providing first and second line arrangements that are connected to a respective inner and outer rotary transformer assembly and enable a corresponding at least partial division of (primary) electrical energy supply and (primary) information transmission between these rotary transformer assemblies. However, it can also be provided that information and/or electrical energy is transmitted via both rotary transformer assemblies, but one electrical energy transmission exceeds the other. The electrical energy transmission can generally take place to perform work and/or to supply voltage to other components. The information can in turn be analog or digital signals.

The method may include any further step, any further development and any further feature to provide all of the above or below interactions, operating states and functions. In particular, the method may be executable or be executed with a machine axis arrangement according to any of the above or below aspects.

• 1 eine schematische Darstellung eines Koordinatenmessgeräts, umfassend eine Maschinenachsenanordnung gemäß einem Ausführungsbeispiel der Erfindung, die ein erfindungsgemäßes Verfahren ausführt;
• 2 eine Detaildarstellung einer Dreh-Schwenk-Einheit des Koordinatenmessgeräts aus 1;
• 3 eine Schnittansicht der Maschinenachsenanordnung des Koordinatenmessgeräts aus 1;
• 4 ein Verlaufsschema zur Schilderung eines erfindungsgemäßen Verfahrens.

In the following, an embodiment of the invention is explained with reference to the attached schematic figures. They show:

• 1 a schematic representation of a coordinate measuring machine comprising a machine axis arrangement according to an embodiment of the invention, which carries out a method according to the invention;
• 2 a detailed view of a rotary-swivel unit of the coordinate measuring machine from 1 ;
• 3 a sectional view of the machine axis arrangement of the coordinate measuring machine 1 ;
• 4 a flow chart describing a process according to the invention.

1 shows a coordinate measuring machine 10. The coordinate measuring machine 10 is used to measure an object 12. For this purpose, an optical sensor device 14 is provided, which in particular has a conform cal white light sensor or chromatic optical sensor device.

To align the optical sensor device 14 with respect to the object 12 in space, a rotary-swivel unit 16 is provided, which enables rotation of the optical sensor device 14 about two spatial axes and thus its alignment in a desired spatial direction. One of the machine axis arrangements that is installed in the rotary-swivel unit 16 (namely the rotary axis that rotates the swivel axis) is described below using 3 explained in more detail. This machine axis arrangement is in 1 not provided with a separate reference symbol because it is not recognizable or hidden there.

The coordinate measuring machine 10 is arranged on a base 18. A portal 20 is mounted so that it can move in a Y direction relative to this base 18. A carriage 22 is mounted on the portal 20 so that it can move in an X direction. Within the carriage 22, a sleeve 24 is mounted so that it can move in a Z direction. The X direction, the Y direction and the Z direction together form a Cartesian coordinate system. In this way, a suitable arrangement of the optical sensor device 14 relative to the object 12 arranged on the base 18 is possible through the translational movement of the portal 20, the carriage 22 and the sleeve 24 and through the use of the two axes of rotation of the rotary-swivel unit 16.

The portal 20, the carriage 22 and the sleeve 24 together form a support structure 26. In principle, other support structures 26 for coordinate measuring machines 10 are also known and can be provided, for example horizontal arm support structures, etc. Furthermore, a scale 28 in the Y direction, a scale 30 in the X direction and a scale 32 in the Z direction are shown. These enable the positioning of the portal 20, the carriage 22 and the sleeve 24 in space to be recorded, so that the positioning of the optical sensor device 14 is known at any time due to the known rotational positions of the rotary-swivel unit 16 in a measuring room.

In principle, any of the movements described can be generated by means of machine axis arrangements according to the invention, which are coupled to the corresponding moving components in a torque-transmitting manner.

A control device 34 is used to control the coordinate measuring machine 10. As a rule, a data processing device 36 is provided in the control device 34 in order to control the coordinate measuring machine 10 and evaluate the measurement results. The control device 34 can also control the individual machine axis arrangements of the coordinate measuring machine 10 and in particular the drive units installed there.

Furthermore, an input device 38 is shown schematically, which can be provided for the input of data by a user. Furthermore, a display device can be provided to show the measurement results to a user. The illustrated design and arrangement of the control device 34, the data processing device 36 and the input device 38 is to be understood as merely schematic and exemplary. It can be designed completely differently or, for example, can also be at least partially integrated into the base 18 of the coordinate measuring machine 10.

2 shows an enlarged view of the area around the rotary-swivel unit 16. The sensor device 14 can be seen again, which can be positioned in space by means of the rotary-swivel unit 16. For this purpose, the rotary-swivel unit 16 comprises two rotary machine axes, namely a rotary axis 48 and a swivel axis 52, the respective rotary axes of which are shown in dashed lines. In principle, both of these axes can be implemented by means of a machine axis arrangement according to the invention. As will be shown below with reference to 2 However, as explained above, only the rotation axis 48 is provided by means of a machine axis arrangement according to the invention or, in other words, is realized as such. In the view of 2 the rotation axis 48 enables the sensor device 14 to rotate about a vertical spatial axis (or the Z axis). For this purpose, a swivel unit 62, to which the sensor device 14 is indirectly attached, is rotated about the corresponding spatial axis.

The swivel unit 62 itself also comprises a machine axis arrangement in the form of the swivel axis 52, with which the sensor device 14 can be rotated by an 2 horizontal spatial axis 52 (or the X-axis) can be rotated.

Furthermore, one can see in 2 that the rotation axis 48 is accommodated in a rotation unit 46 or extends from this. The rotation unit 46 is rigidly coupled to the sleeve 24. The sensor device 14 is accommodated in a sensor head 63 that can be pivoted by the pivot unit 62. Furthermore, an optional sensor axis 53 is shown, about which the sensor device 14 can be rotated.

In the following, referring to 3 a machine axis arrangement 80 according to the invention is explained, as it is used in the rotary unit 46 in the form of the rotary axis 48 of the rotary-swivel unit 16 2 The machine axis arrangement 80 comprises a housing arrangement 82, which in the case shown is generally hollow-cylindrical. The housing arrangement 82 has 3 not shown mudguards can be attached so that the 2 shown appearance of the rotary unit 46 is obtained. The components of the machine axis arrangement 80 explained below are each at least partially accommodated within the housing arrangement 82 or, in other words, positioned within it.

Please note that 3 shows a sectional view through the machine axis arrangement 80, wherein the sectional plane contains a rotation axis R explained below. However, not all of the sectioned components are shown hatched, since this is only a schematic view.

The machine axis arrangement 80 comprises a shaft 84 designed as a hollow shaft, which is arranged around a 3 horizontally extending rotation axis R. The rotation axis R corresponds to the 2 shown vertical dashed axis, which indicates the position or function of the rotation axis 48. In the case shown, the shaft 84 serves as a torque-transmitting drive shaft, but this is not mandatory.

The shaft 84 comprises a connecting section 124 at a first axial end, with which it is coupled to a drive-gear arrangement 86 (not explained in detail here) in a torque-transmitting manner. More precisely, the shaft 84 is connected to the gear of the drive-gear arrangement 86 via screw connections 92 and can be rotated about the rotation axis R in accordance with a rotation of the gear. At its opposite second axial end, the shaft 84 is also connected to an inner ring 88 of a bearing arrangement 90 via screw connections 92 and rotates it. More precisely, the inner ring 88 is rotatably mounted within the housing arrangement 82 via a ball bearing arrangement. The inner ring 88 is also connected to the swivel unit 62 made of 2 coupled to rotate it around the rotation axis R.

As already described, the shaft 84 is designed as a hollow shaft and has a recess 96 which extends through the shaft 84 in the form of a through hole with several diameter steps. The recess 96 runs along and concentrically to the axis of rotation R.

In order to ensure a power supply and information transmission between the rotary unit 46 and the swivel unit 62 (as well as the sensor device 14 moved by the swivel unit 62) 2 To enable this, the machine axis arrangement 80 comprises two rotary transmitter assemblies in the form of slip ring assemblies 98, 100. More precisely, an outer slip ring assembly 98 and an inner slip ring assembly 100 are provided. The outer slip ring assembly 98 comprises an outer element (ie an element located radially outward with respect to the axis of rotation R) 102. This rests against an inner wall 83 of the housing arrangement 82 and is aligned concentrically with the axis of rotation R via the corresponding diameter fit. An axial fixing takes place via a screw connection (not shown) of a flat surface of the outer element 102 with a flange. The outer element 102 is generally annular and has a radial inner region 104 (or inner surface) extending concentrically to and around the axis of rotation R, which defines a circular cylinder jacket surface.

The outer slip ring assembly 98 further comprises an inner element (i.e. an element that is located radially further inward than the outer element 102) 106. This is also ring-shaped and has a radial outer region 108 (or an outer surface), which also extends concentrically to and around the axis of rotation R and defines a circular cylinder surface. The inner region 104 of the outer element 102 and the outer region 108 of the inner element 106 are thus opposite one another. It can thus be seen that the inner element 106 is completely accommodated in the outer element 102 and that these elements 106, 102 basically have different diameters. In the context of the exemplary embodiment described, all diameter dimensions are related to a plane that extends orthogonally to the axis of rotation R.

Furthermore, the space between the inner region 104 and the outer region 108 defines a transmission region (or contact circle) over which the electrical energies and/or signals explained below can be transmitted. This transmission region in turn extends in a ring shape around and concentrically to and along the axis of rotation R and does not intersect it.

Not separately in 3 It is shown that the elements 102, 106 of the outer slip ring assembly 98 are in electrical contact with one another in accordance with conventional slip ring designs. More specifically, a plurality of individual electrically conductive tracks are provided on the inner region 104 of the outer element 102. Each of these tracks can be provided with an individual signal and/or which can be used for an individual electrical energy. On the outer region 108 of the inner element 106, however, contact elements are provided for each track, for example in the form of wire brackets, which engage in the corresponding tracks or are in electrically conductive contact with them. In principle, electrical energy (e.g. an electrical load or electrical power) and/or electrical signals can thus be transmitted between the outer element 102 and the inner element 106. A reverse distribution of wire brackets and tracks between the inner and outer elements 106, 102 is also possible.

In the variant of 3 It should also be emphasized that the inner element 106 of the outer slip ring assembly 98 is coupled for common rotation with the output shaft 84. More precisely, the inner element 106 rests against an outer surface 94 of the shaft 84 with an inner surface 110 facing away from its outer region 108. Rotation of the shaft 84 is transmitted via a driver (not shown) (for example a pin engaging in a bore) to the inner element 106, which rotates relative to the outer element 102. The driver preferably has at least slight radial play and no axial limitation. This enables the torque transmission from the drive gear unit 86 not to take place via the outer slip ring assemblies 98 and/or the general accuracy of the machine axis arrangement 80 (or the torque transmission with the shaft 84) not to be negatively influenced by the outer slip ring assembly 98. In particular, it should be noted that both slip ring assemblies 98, 100 are self-supported in a manner known per se and for this purpose have their own ball bearings (not shown). These should not influence the rotation of the shaft 84 as much as possible in order to ensure the high accuracy of the machine axis arrangement 80 that is desired, particularly in the context of coordinate measuring machines. Instead, a targeted decoupling of the shaft 84 and the slip ring assembly 98 takes place via the driver structure, which is deliberately subject to play. In a generally known manner, energy or signal transmission is still possible despite the rotation due to the described electrically conductive contacts or connections between the outer and inner elements 102, 106.

To enable such transmissions, a first line arrangement 112, which is arranged in 3 indicated by dashed lines, to the outer element 102 and connected to it in an electrically conductive manner. The inner element 106 is also connected to a line arrangement 113, which leads through free spaces within the inner ring 88 to the swivel unit 62, which rotates together with the shaft 84 and thus the inner element 106. 2 The two line arrangements 112 and 113 can also be understood as individual line sections of a common (first) line arrangement.

In the case shown, electrical energy for driving a further machine axis arrangement within the swivel unit 62 (i.e. the drive installed there to enable rotation of the swivel axis 52) is transmitted to the outer element 102 via the first line arrangement 112 and from there to the electrical paths of the inner element 106 via the contacts (not shown separately). From there, it reaches the components of the swivel unit 62 to be driven via the further line arrangement 113. The electrical energy can also be provided and/or transmitted in the form that current is transmitted for measuring systems, a probe change magnet or a general voltage supply for the sensor device 14. In the example shown, the line arrangement 112 can also transmit signals in the direction of the swivel unit 62 or receive them from it (or the sensor device 14 attached to it) and, for example, in the direction of the control device 34. 1 Examples include analog signals from measuring systems and/or signals in the form of a plate recognition or a tachometer signal.

As already mentioned, the machine axis arrangement 80 also comprises a further rotary joint assembly in the form of an inner slip ring assembly 100. This slip ring assembly 100 is referred to as an inner assembly because it has a smaller diameter than the outer slip ring assembly 98. In particular, and as explained in more detail below, it is accommodated in the outer slip ring assembly 98, at least in sections.

In detail, the inner slip ring assembly 100 again comprises an outer element 114, which is arranged radially further outward than an inner element 116 and accommodates the latter. The outer element 114 is again annular or hollow-cylindrical and rests on an inner side of the recess 96. More precisely, it is coupled to this inner side via an analog driver, as explained above, so that the outer element 114 rotates together with the shaft 84. An axial fixing can again be carried out by screwing a flat surface to a flange (not shown). On its inner region 118 facing the rotation axis R, which in turn is designed as a circular cylinder surface and extends along and concentrically to the rotation axis R, the outer element 114 has contact elements (not shown separately) analogous to the outer element 102 of the outer slip ring assembly 98. These engage in electrical conductor tracks (not shown separately) that are arranged on an outer surface of the inner element 116.

The outer element 114 also has a larger diameter than the inner element 116. The space between these elements 114, 116 also defines a transmission area, which has already been explained with reference to the outer slip ring assembly 98, which in turn extends in a ring shape around, concentrically to and along the axis of rotation R and in particular does not intersect it.

The inner element 116 is designed as a hollow cylinder or hollow shaft extending along and concentrically to the rotation axis R. At its end region accommodated in the outer element 114, the inner element 116 has conductor tracks designed according to conventional slip ring designs in order to enable energy or signal transmission between the outer and inner elements 114, 116 in principle. The design of the inner element 116 as a hollow shaft enables cables to be passed through for connection to the conductor tracks, for example. Furthermore, an optional optical fiber (not shown) can be guided through the inner element 116, preferably in such a way that it extends along the rotation axis R and is therefore not subjected to any twisting.

The inner element 116 is further coupled to a stationary component (not shown) of the machine axis arrangement 80 (e.g. a housing of the drive gear unit 86) via a fastening section 120, which is located in an end region facing away from the outer element 114. This is preferably done with play in order to at least partially decouple the slip ring assembly 100 from the shaft 84 in particular and to ensure a desired accuracy of the machine axis arrangement 80.

In order to transmit electrical energy and/or signals by means of the inner slip ring assembly 100, a second line arrangement 115 is provided, which 3 indicated by dashed lines and is connected to a coupling section 126 (eg a plug section) of the inner element 116 near its fastening section 120. Signals transmitted by the line arrangement 115 can then be transmitted to the conductor tracks of the inner element 116 (not shown separately) (for example via lines within the inner element 116 (not shown separately), which are electrically conductively connected to the contact elements of the outer element 114.

The outer element 114 is in turn connected to a line arrangement 130, which extends through free spaces in the inner ring 88 in the direction of the pivot unit 62. The line arrangements 115 and 130 can also be understood as individual sections of a common (second) line arrangement.

In the case shown, information is transmitted via the first line arrangement 115 (but also the further line arrangement 130), in particular in the form of electrical analog or digital signals. These are, for example, control signals that are generated by the control device 34 from 1 to the sensor device 14. Conversely, measurement signals can also be transmitted from the sensor device 14 to the control device 34. This takes place in a manner known per se via the electrical connection provided by the inner slip ring assembly 100. In addition, the first line arrangement 115 can also transmit electrical energy, which is preferably less than the energy transmitted via the outer slip ring assembly 98 or the line arrangements 112, 113 there. For example, energy can be transmitted in the form of Power-over-Ethernet (PoE). Because the inner slip ring assembly 100 primarily serves to transmit information and transmits no or comparatively only lower electrical energy, the coupling section 126 can also be specially designed for connection to a corresponding data connector (for example with an Ethernet connector, not shown in each case). This increases the data transmission quality that can be achieved with the machine axis arrangement 80. According to a variant not limited to the present embodiment, the first line arrangement 115 (and/or 130) can comprise at least two twisted pair connections and/or be part of a bus system.

Furthermore, it is provided that the data transmission via the slip ring assembly 100 takes place according to the CAT6 standard and/or generally in an impedance-controlled manner, which is not limited to the specific embodiment. In order to reduce additional interference and in particular crosstalk, the individual lines connected to the slip ring assembly 100 can be twisted, spaced and/or shielded in a suitable manner. It is also provided that the slip ring assembly 100 enables signal transmission with a bandwidth of at least 100 MHz and preferably at least 200 MHz (e.g. at least 250 MHz) and a rate of at least 1 Gigabit/s.

The 3 The clearly visible difference in diameter between the outer and inner slip ring assembly 98, 100 can be described as follows: A diameter of the outer element 102 of the outer assembly 98, in particular a largest or smallest diameter thereof, but also a diameter of the inner element 106, in particular a largest or smallest diameter thereof, exceeds all diameters of the inner slip ring assembly 100. In particular, a diameter of the inner region 104 or outer region 108, as shown in 3 marked, or an electrical contact area between the inner element 102 and 106, which extends between these areas 104, 108.

In an analogous manner, the diameter of the inner slip ring assembly can be considered to be a (largest or smallest) diameter of its outer element 114 or inner element 116. However, the diameter of a contact area (or transmission area) between these elements 114, 116, via which the described information is transmitted, can also be considered.

Because the outer slip ring assembly 98 generally has a larger diameter than the inner slip ring assembly 100, the latter can be accommodated in the outer slip ring assembly 98 at least in sections, as shown in 3 is also shown. In other words, the slip ring assemblies 98, 100 can thus be arranged at least partially pushed into one another and/or nested within the machine axis arrangement 80. In the case of 3 This is done in particular in such a way that the inner and outer slip ring assemblies 98, 100 extend along a common area B of the rotation axis R or axially span this area B. Although comprehensive transmission options are thus provided, the axial installation space or space required for the slip ring assemblies 98, 100 is smaller than if only a single slip ring assembly 98, 100 with a larger axial length were provided. Due to the described diameter ratios of its slip ring assemblies 98, 100, the exemplary embodiment is characterized by a comparatively small axial installation space and space requirement. This also offers the advantage that the shaft 84 can be comparatively short and lever arms within the machine axis arrangement 80, which impair accuracy, can also be correspondingly short. The shaft 84 is also less sensitive to torsion due to the reduced length and can therefore, for example, be constructed with a lower weight.

Furthermore, at least one of the slip ring assemblies 98, 100, namely the inner one, can be designed with a comparatively small diameter. This enables the high transmission capabilities already described, since interference can be reduced, for example due to the capacitance of the conductor tracks. If only a single corresponding small-sized slip ring assembly 98, 100 were provided, the number of lines and/or cables that can be coupled to it would be limited due to the limited inner diameter (for example because they would all have to be routed through the inner element 116). This is compensated for by providing an additional and correspondingly larger-sized outer slip ring assembly 98.

Further advantages are that the transmission of electrical energy (or electrical loads and/or electrical power), which are primarily used to perform actual work, and the transmission of information (for example in the form of signals or data) can be at least partially separated by means of the first and second line arrangements 112 and 115. In particular, these transmissions can be at least partially divided between the different slip ring assemblies 98, 100, in particular in such a way that the inner slip ring assembly 98 only transmits a lower electrical energy or even no electrical energy at all. As an example, a current of 2.5 A can be transmitted by the outer slip ring assembly 98, whereas currents lower by a factor of at least 10 or at least 5 can be transmitted via the inner slip ring assembly 100. Disturbing influences of the potentially high currents or voltages transmitted by means of the first line arrangement 112 therefore have no effect or only a minimally distorting effect on the information transmitted by means of the second line arrangement 115. In particular, it can be provided that only particularly critical data and signals and/or data and signals to be transmitted at high transmission rates are transmitted via the inner slip ring assembly 98, whereas no or at most less critical data and signals can be transmitted via the outer slip ring assembly 100.

Finally, there is an advantage in that both slip ring assemblies 98, 100 can be designed according to the cheaper manufacturing variant described in the introduction, in which several individual ring elements are combined with one another or arranged next to one another. Due to the By arranging the slip ring assemblies 98, 100 one inside the other as described, the associated higher space requirement compared to galvanically manufactured slip rings can be partially or completely compensated. Depending on the specific design, even more cost-effective and axially shorter arrangements of the slip ring assemblies 98, 100 can be provided compared to galvanically manufactured slip rings. The use of ring elements with a smaller diameter can also result in a higher signal transmission quality compared to galvanically manufactured conductor tracks with a larger diameter, since the risk of crosstalk is lower.

Finally, it is understood that other rotary transmission assemblies than the slip ring assemblies 98, 100 shown can also be used (for example optical, capacitive or inductive). This applies in particular if their transmission range extends in an analogous manner around the rotation axis R and diameters thereof can be selected in such a way that an analogous arrangement as in the example shown is possible.

Because the inner slip ring assembly 100 can primarily or exclusively transmit data or signals, at least there the required interfaces (or disconnection points or plug-in points) of the line arrangements 115, 130 can be reduced compared to a single slip ring, which primarily transmits electrical energy and possibly also information. In particular, a connection interface in the form of a plug or similar can be optimized for primary or pure data transmission (for example according to the CAT6 standard). As described, in particular data can be transmitted via the inner slip ring assembly 100 in accordance with a predetermined transmission protocol and/or the slip ring assembly 100 can form a (connection) component of a BUS system. Information that is not to be transmitted using the transmission protocol and/or bus system can, however, be transmitted via the outer slip ring assembly 98.

In 4 Finally, a flow chart is shown to explain a method according to the invention. This provides for the transmission of electrical energy and information by means of a machine axis arrangement 80 which is designed, for example, according to the exemplary embodiment described above. In a step S1, the electrical energy to be transmitted is supplied to the machine axis arrangement 80. In a step S2, which can generally be carried out at a different time or in parallel to step S1, the information to be transmitted is supplied to the machine axis arrangement 80. Then, in a step S3, which can have any relative time relationship to step S2, the electrical energy is transmitted largely or exclusively by means of one of the inner and outer rotary transformer assemblies 100, 98. Furthermore, in a step S4, which can have any relative time relationship to step S1, the information is transmitted largely or exclusively by means of the other of the inner and outer rotary transformer assemblies 100, 98. For the described transmissions, the line arrangements 112,113 and 115, 130 described above come into consideration.

Claims (10)

Machine axis arrangement (80) with a shaft (84) rotatable about a rotation axis (R); and an inner and an outer rotary transformer assembly (100, 98), each comprising an inner element (106, 116) and an outer element (102, 114) that are rotatable relative to one another and are designed to cooperate to transmit information and/or electrical energy; wherein one of the inner element (106, 116) and outer element (102, 114) of a respective rotary transformer assembly (100, 98) is coupled to the shaft (84); and wherein a diameter of the outer rotary transformer assembly (98) is larger than a diameter of the inner rotary transformer assembly (100), characterized in that the machine axis arrangement (80) comprises a first line arrangement (112) for providing an electrical energy supply and a second line arrangement (115) for transmitting information and no or at most less electrical energy than is transmitted by means of the first line arrangement (112), wherein the first line arrangement (112) is connected to one of the inner and outer rotary transformer assemblies (100, 98) and the second line arrangement (115) is connected to the corresponding other rotary transformer assembly (100, 98). Machine axis arrangement (80) according to Claim 1 , wherein the rotary transformer assemblies (98, 100) are arranged at least partially along a common region (B) of the axis of rotation (R). Machine axis arrangement (80) according to Claim 1 or 2 , wherein the inner element (106) of the outer rotary transformer assembly (98) and/or the outer element (114) of the inner rotary transformer assembly (100) is coupled to the shaft (84) for common rotation. Machine axis arrangement (80) according to one of the preceding claims, wherein the outer element (102) of the outer rotary transformer assembly (98) and/or the inner element (116) of the inner rotary transformer assembly (100) is rotationally decoupled from the shaft (84). Machine axis arrangement (80) according to one of the preceding claims, wherein the inner element (116) of the inner rotary transformer assembly (100) extends at least in sections substantially concentrically along the axis of rotation (R). Machine axis arrangement (80) according to one of the preceding claims, wherein the shaft (84) has a recess (96) extending at least partially along the axis of rotation (R), in which the inner rotary transformer assembly (100) is at least partially received. Machine axis arrangement (80) according to one of the preceding claims, wherein the outer element (102) of the outer rotary transformer assembly (98) is arranged on an inner wall region (83) of a housing arrangement (82) of the machine axis arrangement (80). Machine axis arrangement (80) according to one of the preceding claims, wherein at least one of the inner and outer rotary transformer assemblies (100, 98) is configured for signal transmission with a bandwidth of at least 100 MHz and preferably at least 250 MHz and/or for signal transmission with a transmission rate of at least 1 gigabit/s. Rotary-swivel unit (16), in particular for use in a coordinate measuring machine (10), comprising a machine axis arrangement (80) according to one of the preceding claims. Method for transmitting electrical energy and information by means of a machine axis arrangement (80), wherein the machine axis arrangement (80) is designed according to one of the preceding claims and the method comprises: - transmitting electrical energy by means of a first of the inner and outer rotary transformer assemblies (100, 98); and - transmitting information by means of the corresponding other rotary transformer assembly (100, 98) and no or at most less electrical energy than is transmitted via the first rotary transformer assembly (100, 98).

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