Force-measuring bearing flange

Abstract

The invention relates to a spindle (10, 30), in particular a tool and / or workpiece spindle, comprising at least one spindle housing (32), a spindle bearing (33, 34), and a bearing flange (35) for receiving the spindle bearing (33, 34) and for securing same to the spindle housing (32), the bearing flange (35) having at least one bearing receiving part (36) for receiving the spindle bearing (33, 34) and a securing part (37) for securing the bearing flange (35) to the spindle housing (32). According to the invention, the forces acting on the spindle while a workpiece is being machined are to be determined by means of relatively simple means and with high accuracy. According to the invention, the bearing flange (35) of the spindle (10, 30) comprises at least one sensor element (44) for determining an elastic deformation of the bearing flange (35) as a result of an external force exerted on the spindle (10, 30). The force is therefore measured on a non-rotating part of the spindle, thus allowing a highly precise and cost-effective force-measuring process.

Description

[0001] Description

[0002] Force-measuring bearing flange

[0003] The invention relates to a spindle, in particular a tool and / or workpiece spindle, comprising at least one spindle housing, one spindle bearing and one bearing flange for receiving the spindle bearing and for fastening it to the spindle housing, wherein the bearing flange has at least one bearing receiving part for receiving the spindle bearing and one fastening part for fastening the bearing flange to the spindle housing.

[0004] Furthermore, the invention relates to a bearing flange for a spindle, in particular a tool or workpiece spindle, comprising at least one bearing receiving part for receiving the spindle bearing and a fastening part for fastening the bearing flange to a spindle housing.

[0005] Furthermore, the invention relates to a machine, in particular a machine tool or a robot.

[0006] Furthermore, the invention relates to a method for detecting a force that acts on the machine during the machining of a workpiece by a tool using a machine, wherein the machine comprises at least one spindle for fastening and / or moving a tool or workpiece, wherein the spindle comprises at least one spindle housing, one spindle bearing and one bearing flange for receiving the spindle bearing and for fastening to the spindle housing, wherein the bearing flange has at least one bearing receiving part for receiving the spindle bearing and one fastening part for fastening the bearing flange to the spindle housing, wherein the bearing receiving part and the fastening part are elastically connected to each other by at least one elastically deformable connecting element.

[0007] Many machines use spindles to move or clamp parts. For example, in a machine tool, tools or workpieces are attached to and driven by a tool or workpiece spindle. During machining operations using a machine tool, forces can be so high that they can damage the tool or the machine, especially the main spindle, or reduce the tool life. The actual forces at play are often unknown and can frequently only be estimated using relatively inaccurate calculation models or measured using expensive measuring technology. Knowledge of these forces is crucial for process monitoring, quality assurance, condition monitoring, and tool wear assessment.

[0008] Various methods for determining the forces acting on a tool during the machining of a workpiece using a machine tool are known from WO 2022 / 229076. These forces can be determined by simulating the machining process or by measuring the currents supplied to the machine tool's drives, particularly the tool spindle. These methods are complex and sometimes lead to inaccurate results.

[0009] The object of the present invention is to determine forces acting on a spindle with relatively simple means and with high accuracy.

[0010] This problem is solved by a spindle with the features according to claim 1, i.e. a spindle, in particular a tool and / or workpiece spindle, comprising at least a spindle housing, a spindle bearing and a bearing flange for receiving the spindle bearing and for fastening it to the spindle housing, wherein the bearing flange has at least one bearing receiving part for receiving the spindle bearing and a fastening part for fastening the bearing flange to the spindle housing, wherein the bearing flange has at least one sensor element for determining an elastic deformation of the bearing flange as a result of an external force exerted on the spindle.

[0011] Furthermore, the problem is solved by a bearing flange for a spindle with the features according to claim 10, i.e. a bearing flange for a spindle, in particular a tool or workpiece spindle, comprising at least one bearing receiving part for receiving the spindle bearing and a fastening part for fastening the bearing flange to a spindle housing, wherein the bearing flange has at least one sensor element for determining an elastic deformation of the bearing flange as a result of an external force exerted on the spindle.

[0012] Furthermore, the problem is solved by a machine according to claim 13, i.e., a machine, in particular a machine tool or robot, comprising a spindle according to any one of claims 1 to 9. In addition, the problem is solved by a method for detecting a force with the features according to claim 14, i.e., a method for detecting a force that acts on the machine during the machining of a workpiece by a tool using a machine, wherein the machine comprises at least one spindle for fastening and / or moving a tool or workpiece, wherein the spindle comprises at least one spindle housing, one spindle bearing, and one bearing flange for receiving the spindle bearing and for fastening it to the spindle housing, wherein the bearing flange comprises at least one bearing receiving part for receiving the spindle bearing and one fastening part for fastening the bearing flange to the spindle housing.wherein the bearing receiving part and the fastening part are elastically connected to each other by at least one elastically deformable connecting element and wherein the elastically deformable connecting element has at least one sensor element with which an elastic deformation of the elastically deformable connecting element is determined and wherein the force causing this elastic deformation is deduced from the elastic deformation.

[0013] The invention offers the advantage that the forces which are captured during the machining of a workpiece by means of a tool are captured directly at the point on the machine where they are transferred from the tool or workpiece to the machine, namely the tool- or workpiece-side bearing flange of the spindle.

[0014] A spindle, especially a tool spindle or a workpiece spindle, is a central component in machine tools such as lathes, milling machines, and drilling machines. Its purpose is to hold the tool or workpiece and set it in rotation in order to machine the workpiece using the tool.

[0015] A spindle comprises several essential components that work together to enable precise and efficient machining of the workpiece. Common components include:

[0016] - A (spindle) housing.

[0017] Bearings: These hold the spindle shaft in position and reduce friction during rotation. Precision bearings are particularly important because they must withstand high speeds and loads. Rolling bearings, especially ball bearings, are commonly used.

[0018] - Bearing flanges: These are used to attach the bearings to the housing.

[0019] - A spindle shaft: It transmits the motor's power to the tool and must be manufactured with extreme precision to minimize vibrations and ensure high accuracy. - A motor or drive unit: This drives the spindle shaft. Various motor types exist, such as direct-drive motors or belt-drive systems, which are used depending on the application.

[0020] - Cooling and lubrication systems: These are essential to control heat generation in the spindle and to increase the spindle's service life.

[0021] - A tool or workpiece holder: This is the connecting element between the spindle and the tool or workpiece. It must be very stable and precise to securely fix the tool or workpiece and enable high speeds.

[0022] By measuring the force at the bearing flange (on the tool or workpiece side), the invention enables force measurement in the stationary component, which—in contrast to force measurement in the moving or rotating component—represents a proven and cost-effective method for measuring forces. The strain measurement is intended to take place directly at or within the bearing flange, which is typically solid and therefore correspondingly rigid. This makes detecting strain within the measurable range difficult.

[0023] A preferred embodiment of the invention therefore provides that the bearing flange according to the invention is designed in such a way that the compliance of the spindle in the axial and / or radial direction is significantly increased by design measures.

[0024] Up to now, spindles for machine tools (tool spindles, workpiece spindles) have been designed to be as rigid as possible in order to achieve the highest possible positioning accuracy of the tool and / or workpiece.

[0025] In particular, bearing flanges for spindles were designed so that the bearing housing part for receiving the spindle bearing and the fastening part for attaching the bearing flange to the spindle housing were as rigid and robust as possible. Elastic deformation between these two parts of the bearing flange was undesirable and had to be avoided.

[0026] In contrast, the bearing flange according to the invention, in the aforementioned embodiment, exhibits a certain degree of elasticity between the bearing receiving part and the mounting part of the bearing flange. The use of this special bearing flange specifically increases the elasticity of the spindle and reduces its stiffness to counteract chatter vibrations. The compliance of the bearing flange is increased such that the overall compliance at the tool interface does not exceed a certain limit, but is nevertheless high enough to allow the elastic strains of the structure to be measured by conventional sensor elements such as strain gauges.

[0027] The desired compliance is achieved in particular by elastically connecting the bearing support and the mounting element by at least one elastically deformable connecting element. Advantageously, the sensor element for determining elastic deformation of the elastically deformable connecting element is encompassed by the elastically deformable connecting element or arranged or attached to the elastically deformable connecting element. The sensor element is thus located in a region of the bearing flange where the greatest deformation occurs under an external force.

[0028] One embodiment of the invention provides that the elastically deformable connecting element comprises at least one rod and / or strut, in particular a plurality of rods and / or struts, or is designed as a rod and / or strut, in particular as a plurality of rods and / or struts, wherein at least one sensor element is arranged on at least one rod and / or at least one strut. In particular, the number, dimensions, distribution, orientation, or materials used of the rods or struts can influence the elastic properties of the bearing flange and thus the spindle as such in a variety of ways. The rods or struts are preferably uniformly flat or plate-shaped.

[0029] The bearing flange can, for example, be designed like a spoked wheel. In this design, a portion of the bearing flange, which houses the rolling bearing(s) and guides the spindle shaft, is connected to a stationary outer section via a defined number and configuration of bars or struts. The greatest deformation under external load occurs on these bars or struts, making them the optimal location for mounting the sensor elements.

[0030] The bearing housing, the fastening element, and the elastically deformable connecting element are advantageously formed in one piece. This simplifies manufacturing and reduces production costs.

[0031] Besides rods and / or struts, a variety of other design options are possible to achieve the intended deformability or elasticity of the elastically deformable connector. For example, it could also be designed, at least in its essential form, as an arc, funnel, plate, etc.

[0032] To further increase elasticity, the chosen shape of the elastically deformable connecting element can also be zigzag-shaped, wavy or corrugated, spiral-shaped, etc., at least in sections.

[0033] The bearing housing, the fastening element, and the elastically deformable connecting element are preferably formed in one piece and manufactured in a single operation, e.g., by a metal casting or 3D printing process. Ideally, the three parts are made of the same material. These measures each enable simple and cost-effective manufacturing with good mechanical properties.

[0034] Preferably, the rods or struts connecting the bearing receiving part and the fastening part are evenly distributed around the circumference of the bearing flange. In particular, exactly four or multiples of four rods or struts evenly distributed around the circumference of the bearing flange are present, so that the bearing flange can absorb and dampen forces in any radial direction.

[0035] In a preferred embodiment of the invention, the elastically deformable connecting element, particularly with respect to a cross-section, is inclined at an angle in the range of 30° to 60°, particularly 45°, relative to a spindle axis (longitudinal axis of the spindle). In particular, in an embodiment of the elastically deformable connecting element in the form of a number of rods and / or struts, the rods or struts are inclined at an angle in the range of 30° to 60°, particularly 45°, relative to the spindle axis. This achieves high elasticity in both the axial and radial directions, and in particular, at least approximately the same elasticity in both directions.

[0036] The desired elastic deformability can also be achieved, or additionally achieved, through special material properties of the elastically deformable fastener compared to the bearing support and the fastening component. For this purpose, a different material composition, in particular a "softer" material, would be selected for the elastically deformable fastener than for the other parts of the bearing flange.

[0037] In one embodiment of the invention, the bearing flange is manufactured using a 3D printing process. This makes it possible to easily produce even complex shapes of the elastically deformable connecting element, e.g., in the form of a number of corrugated or bent struts, as well as different material compositions in different areas.

[0038] In one embodiment of the invention, the bearing flange has at least one cooling channel, and in particular a plurality of cooling channels, for conveying a cooling medium to cool the bearing flange and, in particular, the spindle bearing. This variant can also be advantageously manufactured by means of 3D printing.

[0039] Because the elastic deformation of the bearing flange is at least essentially limited to a specific area of ​​the bearing flange, the deformation in this area can be measured particularly well and easily with at least one sensor element.

[0040] Strain gauges, as previously mentioned, are particularly suitable as sensor elements. These are available on the market in a wide variety of designs and are especially cost-effective. Attaching the strain gauges to the surface of the rods or struts is also very simple, for example, by gluing. Integrating sensor elements into the rods or struts, for example by potting, is also possible, but a correspondingly more complex and expensive alternative.

[0041] However, the invention is not limited to the use of strain gauges. In principle, other sensor elements can also be used to determine the strain or compression of the at least one elastic connecting element, e.g. displacement sensors or optical fibers.

[0042] Advantageously, the elastically deformable connecting element is designed such that at least four sensor elements can be arranged on the bearing flange, each offset by 90° with respect to the spindle axis. This arrangement of the sensor elements also allows for accurate determination of the direction in which an external force acts on the bearing flange.

[0043] A further advantage of a machine according to the invention is that it comprises a spindle according to the invention. The machine according to the invention is preferably designed as a machine tool or robot, and the spindle can be connected to a tool, and the movement of the tool can be controlled such that it performs the intended processing and / or manufacturing of a workpiece. In a robot according to the invention, the spindle according to the invention is mounted at the front end of the robot arm or manipulator. The invention is described and explained in more detail below using exemplary embodiments. The following are shown:

[0044] FIG 1 A machine tool with a tool spindle,

[0045] FIG 2 shows a sectional view of a conventional motor spindle,

[0046] FIG 3 shows a sectional view of a motor spindle according to the invention,

[0047] FIG 4 shows a bearing shield of a motor spindle according to the invention in a spatial view,

[0048] FIG 5 shows a preferred embodiment of a bearing shield according to the invention,

[0049] FIG 6 Process steps in the execution of a method according to the invention.

[0050] Figure 1 schematically depicts a machine tool system in the form of a machine tool system 1. The machine tool system 1 comprises a machine tool in the form of a machine tool 2. Furthermore, the machine tool system 1 comprises a numerical control device in the form of a CNC controller 3 connected to the machine tool 2 for controlling the machine tool 2. In addition, the machine tool system 1 comprises an external computing device in the form of a CAD / CAM system 5 connected via a network 4, for example, the Internet.

[0051] The machine tool 2 shown has 3 position-controlled linear axes X, Y and Z, wherein a first support element 7 in the x-direction, a second support element 8 in the y-direction and a third support element 9 in the z-direction is adjustable with respect to a machine coordinate system MKS fixed in position with respect to the machine tool 2.

[0052] The first support element 7 is connected to a stationary machine frame 6 via a linear drive adjustable in the x-direction (not shown). The second support element 8 is connected to the first support element 7 via a linear drive adjustable in the y-direction (not shown), and the third support element 9 is connected to the second support element 8 via a linear drive adjustable in the z-direction (not shown). The third support element 9 carries a motor spindle 10, which is pivotable about a position-controlled rotary axis B parallel to the Y-axis. The motor spindle 10, in turn, has a spindle shaft 11 that is rotatable about a spindle axis (not shown in FIG. 1) and whose speed and / or position is controlled. A tool holder 12 with the attached tool 13 is clamped into the spindle shaft.

[0053] Furthermore, the machine tool 2 includes a position-controlled tool table axis C aligned parallel to the Z-axis, around which a workpiece table 14 can be rotated.

[0054] The tool table 14 is also connected to the stationary machine frame 6 and a workpiece 16 is attached to the tool table 14 by means of the tool holders 15.

[0055] In this embodiment, machine tool 2 has five position-controlled machine axes, enabling relative movement between the tool 13 (a milling cutter in this embodiment) and the workpiece 16. It is therefore a so-called 5-axis machine tool (5-axis machine), although it should be noted that a machine tool can, of course, have more or fewer than five machine axes. For the sake of clarity, the drives for the position-controlled machine axes are not shown in this embodiment.

[0056] The machine tool 2 is connected to the CNC control 3, which determines target values ​​for the machine axes based on a part program and / or manual input to control a relative movement between the tool 13 and the workpiece 16. The CNC control 3 determines the target values ​​primarily based on the part program, in which the movements to be performed by the tool 13 relative to the workpiece 16 are defined in the form of commands or program instructions, usually in the form of G-code.

[0057] Alternatively or additionally, the movement of the tool 13 and / or the workpiece 16 can also be specified by an operator on-site at the machine tool 2 via a manual control unit with operating elements 18 in conjunction with a display device in the form of a screen 17 of the CNC control 3. The operating elements 18 include, in particular, pushbuttons or rotary controls. Advantageously, the screen 17 can also be designed as a touchscreen and thus also as an operating element. The part program is typically generated outside the CNC control 3 in a computing unit external to the CNC control, in this embodiment the CAD / CAM system 5 and a post-processor (not shown) that may be connected downstream of the CAD / CAM system, and is then transferred from there to the CNC control 3, in particular via the network 4.

[0058] In the embodiment shown in FIG. 1, the CNC control 3 and / or the external computing device 5 are configured to first simulate the actual machining of the workpiece 16 using the machine tool 2. For this purpose, digital representations of at least all essential components of the machine tool 2, the tool 13, and the workpiece 16 are stored in the CNC control 3 or the external computing device 5. For the simulation, the CNC control 3 or the external computing device 5 executes, in particular, the same part program that is also executed by the CNC control 3 during actual machining. The simulated machining can be visually displayed on the display 17 of the CNC control 3 and / or a display of the external computing device 5.

[0059] Advantageously, in the embodiment shown in FIG. 1, the tool spindle 10 is designed in the form of a spindle according to the invention, which includes a bearing flange according to the invention (not visible from FIG. 1).

[0060] FIG. 2 shows a sectional view of a conventional motor spindle 20. Particularly visible are a spindle shaft or motor shaft 21, a housing (spindle housing) 22, rolling bearings 23 and 24, and a bearing flange 25 for mounting and fixing the rolling bearings 23 and 24. As can also be seen in the figure, the bearing flange 25 is made of solid material and therefore has high rigidity. Details of the motor that are irrelevant to the invention have been omitted from the figures (especially FIG. 2 and FIG. 3) for the sake of clarity.

[0061] FIG. 3, unlike FIG. 2, shows a sectional view of a motor spindle 30 according to the invention, comprising a spindle shaft or motor shaft 31, a housing 32, and the two rolling bearings 33 and 34. A bearing flange 35 is also visible, which here too serves to fasten and secure the rolling bearings 33 and 34, but differs fundamentally in its construction from the bearing flange 25 shown in FIG. 2. It should also be noted that—unlike in FIGS. 2 and 3—instead of the two spindle bearings or rolling bearings 33 and 34, embodiments with only one bearing, e.g., bearing 33, are also common in this area of ​​the spindle and are covered by the invention. The bearing flange 35 also serves to receive the spindle bearings 33 and 34 and to fasten them to the spindle housing.In contrast to the bearing flange 25, the bearing flange 35 can be divided into at least 3 functionally different areas: a bearing receiving part 36 for receiving the spindle bearings 33, 34, a fastening part 37 for fastening the bearing flange 35 to the spindle housing 32, and an elastically deformable connecting element 38 by which the bearing receiving part 36 and the fastening part 37 are elastically connected to each other.

[0062] In the exemplary embodiment, the elastically deformable connecting element 38 is designed as a number of struts 38, each of which is inclined at an angle of approximately 45° to a spindle axis 39.

[0063] The invention provides that the bearing flange has a sensor element for determining an elastic deformation of the bearing flange as a result of an external force exerted on the spindle.

[0064] In the embodiment of the invention according to FIG. 3, the elastically deformable connecting element in the form of struts 38 has at least one sensor element, in particular a strain gauge 44, for determining elastic deformation of the struts 38. Advantageously, exactly four strain gauges are uniformly attached to the bearing flange 35, i.e., offset by approximately 90° with respect to a spindle axis 19, e.g., by gluing. The elastic deformation of the struts 38 can be measured by means of the strain gauges 44, and thus the force acting on the spindle and its direction can be determined very accurately. Knowledge of the force and its direction can be used in the CNC control 3 (see FIG. 1) to adjust or optimize control parameters relating to the machining of the workpiece, e.g., the feed rate.

[0065] For better illustration, the bearing flange 35 with the bearing receiving part 36, the fastening part 37, the elastically deformable connecting element in the form of a number of struts 38 and the sensor elements in the form of strain gauges 44 are shown again in a spatial view in FIG 4.

[0066] A preferred embodiment of the bearing flange 35 according to the invention is shown in FIG. 5. In such a bearing flange, a stop may be provided, in the embodiment according to FIG. 5 in the form of the projections 40, which restrict the range of elastic deformation or limit it to a maximum possible deformation. Furthermore, as shown in FIG. 5, a damping element 41, e.g., an elastomer or a squeeze film, may be provided in the area of ​​the stop 40, which has a damping effect, particularly in the area of ​​maximum elastic deformation. The damping element 41, like the stop 40, is preferably annular in shape with the spindle axis (not shown in FIG. 5) as its axis of symmetry.

[0067] Furthermore, a bearing flange according to the invention may have cooling channels 42 which enable optimized bearing heat dissipation.

[0068] Furthermore, the bearing flange according to the invention preferably comprises, in the area where the greatest deformation occurs in the elastically deformable connecting element, in the exemplary embodiment the strut 38, as a result of an external force, at least one cavity 43 filled with a damping agent, thereby damping the elastic deformation. Powder particles are particularly suitable as damping agents, as they cause damping (particle damping) due to friction.

[0069] The aforementioned special features of the bearing flange according to the invention can be implemented particularly easily and cost-effectively if the bearing flange is manufactured wholly or at least partially using a 3D printing process. The design of the struts, the cooling channels, the stop elements with the damping ring, and the powder-filled chambers for damping is thus particularly simple and, in particular, possible in a single operation.

[0070] The additional features shown in combination in FIG. 5 (stop elements 40, damping means 41, cooling channels 42, cavities 43 filled with a damping means) can also be present individually in a bearing flange according to the invention, i.e. not in combination with further or all of the features shown or in any combination.

[0071] Compared to a standard solid bearing flange, the use of a spindle according to the invention with a bearing flange according to the invention in a machine tool allows for a significantly higher feed rate (width and depth of cut) of the tools during the milling process, thus increasing milling performance and productivity. At least one sensor element mounted directly on the bearing flange allows for simple and cost-effective monitoring of the forces exerted on the spindle during machining a workpiece. In particular, dynamic load peaks occurring during machining can also be detected. This allows the spindle's capabilities to be fully utilized without overloading it. Specifically, control parameters can be adjusted during machining to ensure optimal machine operation. Advantageously, a spindle according to the invention allows for...In a bearing flange according to the invention, chatter vibrations are shifted to higher feed rates. When conservative milling parameters are selected, it becomes apparent that the milling process is less susceptible to chatter and therefore more stable overall.

[0072] Advantageously, the CNC control 3 shown in FIG. 1, optionally in conjunction with the external computing device 5, allows the machining of the workpiece 16 using the machine tool 2 to be simulated first. For this purpose, a digital twin of the machine tool 2 is used. Therefore, it is also advantageous to provide a digital twin of the spindle 10 or the bearing flange according to the invention (see FIGS. 3 to 5). This allows the properties of the spindle 10 or the bearing flange to be included in the simulation, making it even more accurate and realistic.

[0073] FIG 6 illustrates process steps in a method according to the invention for detecting a force that acts on the machine during the machining of a workpiece by a tool using a machine.

[0074] In a first process step S1, at least one spindle is provided in a machine, preferably a machine tool or a robot, for fastening and / or moving a tool or workpiece, wherein the spindle comprises at least one spindle housing, one spindle bearing and one bearing flange for receiving the spindle bearing and for fastening to the spindle housing, wherein the bearing flange has at least one bearing receiving part for receiving the spindle bearing and one fastening part for fastening the bearing flange to the spindle housing, wherein the bearing receiving part and the fastening part are elastically connected to each other by at least one elastically deformable connecting element and wherein the elastically deformable connecting element has at least one sensor element.In a second process step S2, during the machining of a workpiece with the machine, a sensor signal is generated by means of the sensor element as a function of the elastic deformation of the elastically deformable connecting element.

[0075] In process step S3, the sensor signal is evaluated using an evaluation unit to determine a force acting on the spindle. This force can also include the direction from which the force acts on the spindle.

[0076] The evaluation unit can be integrated into the machine's control unit. Alternatively, the sensor signal can be evaluated outside the control unit, with the evaluation unit, for example, integrated into the spindle. In this case, data generated by the external evaluation unit regarding the measured force is advantageously transmitted to the control unit.

[0077] In process step S4, a reaction is triggered depending on the measured force. There are various possibilities for this reaction. For example, a force threshold can be predefined in the machine's control unit. If the measured force exceeds this threshold, a message can be displayed to the user on the control unit's screen, or an alarm can be triggered. However, it is also possible for the measured force to directly affect the machining of the workpiece. For example, control parameters, such as the tool feed rate, can be adjusted depending on the force. In particular, the control unit automatically determines and sets the control parameters to ensure optimal spindle utilization without overloading and to prevent chatter vibrations.

[0078] Furthermore, in process step S5, the recorded sensor signals and / or data obtained from their evaluation are stored in a data storage device inside and / or outside the control unit and, if necessary, further processed, e.g., in the form of a logbook, an event tracker, or similar, a tachograph for documenting the load history by connecting an IPC, edge devices, etc. In particular, characteristic values ​​with statements about the spindle load, especially in certain operating situations of the machine in question, can be calculated or derived from the force information.

Claims

Patent claims 1. Spindle (10, 30), in particular a tool and / or workpiece spindle, comprising at least a spindle housing (32), a spindle bearing (33, 34) and a bearing flange (35) for receiving the spindle bearing (33, 34) and for fastening it to the spindle housing (32), wherein the bearing flange (35) has at least a bearing receiving part (36) for receiving the spindle bearing (33, 34) and a fastening part (37) for fastening the bearing flange (35) to the spindle housing (32), characterized in that the bearing flange (35) has at least one sensor element (44) for determining an elastic deformation of the bearing flange (35) as a result of an external force exerted on the spindle (10, 30).

2. Spindle (10, 30) according to claim 1, wherein the bearing receiving part (36) and the fastening part (37) are elastically connected to each other by at least one elastically deformable connecting element (38) and wherein the sensor element (44) is encompassed by the elastically deformable connecting element (38) or is arranged on the elastically deformable connecting element (38) for determining an elastic deformation of the elastically deformable connecting element (38).

3. Spindle (10, 30) according to claim 2, wherein the elastically deformable connecting element (38) comprises at least one rod and / or a strut, in particular a plurality of rods and / or struts, or is designed as a rod and / or strut, in particular as a plurality of rods and / or struts, and wherein at least one sensor element (44) is arranged on at least one rod and / or at least one strut.

4. Spindle (10, 30) according to claim 2 or 3, wherein the bearing receiving part (36), the fastening part (37) and the elastically deformable connecting element (38) are formed in one piece.

5. Spindle (10, 30) according to one of the preceding claims, wherein the elastically deformable connecting element (38) is inclined by an angle in the range of 30° to 60°, in particular 45°, relative to a spindle axis (19).

6. Spindle (10, 30) according to one of the preceding claims, wherein four elastic connecting elements, each connected to a sensor element (44), are arranged at 90° intervals with respect to the spindle axis (19) on the bearing flange (35).

7. Spindle (10, 30) according to one of the preceding claims, wherein the bearing flange (35) is manufactured using a 3D printing process.

8. Spindle (10, 30) according to one of the preceding claims, wherein the sensor element (44) is designed as a strain gauge (44).

9. Spindle (10, 30) according to one of the preceding claims, wherein the spindle is designed as a motor spindle and the bearing flange (35) is designed as a bearing shield of the motor spindle.

10. Bearing flange (35) for a spindle (10, 30), in particular a tool or workpiece spindle, comprising at least one bearing receiving part (36) for receiving the spindle bearing (33, 34) and a fastening part (37) for fastening the bearing flange (35) to a spindle housing (32), characterized in that the bearing flange (35) has at least one sensor element (44) for determining an elastic deformation of the bearing flange (35) as a result of an external force exerted on the spindle (10, 30).

11. Bearing flange (35) according to claim 10, wherein the bearing receiving part (36) and the fastening part (37) are elastically connected to each other by at least one elastically deformable connecting element (38) and wherein the sensor element (44) is encompassed by the elastically deformable connecting element (38) or is arranged on the elastically deformable connecting element (38) for determining an elastic deformation of the elastically deformable connecting element (38).

12. Bearing flange (35) according to claim 10 or 11, wherein the elastically deformable connecting element (38) comprises at least one rod and / or a strut, in particular a plurality of rods and / or struts, or is designed as a rod and / or strut, in particular as a plurality of rods and / or struts, and wherein at least one sensor element (44) is arranged on at least one rod and / or at least one strut.

13. Machine, in particular machine tool (2) or robot, comprising a spindle (10, 30) according to any one of claims 1 to 9.

14. Method for detecting a force acting on the machine (2) during the machining of a workpiece (16) by a tool (13) using a machine (2), wherein the machine (2) has at least one spindle (10, 30) for fastening and / or moving a 17 tool (13) or workpiece (16), wherein the spindle (10, 30) comprises at least one spindle housing (32), one spindle bearing (33, 34), and one bearing flange (35) for receiving the spindle bearing (33, 34) and for fastening it to the spindle housing (32), wherein the bearing flange (35) comprises at least one bearing receiving part (36) for receiving the spindle bearing (33, 34) and one fastening part (37) for fastening the bearing flange (35) to the spindle housing (32), wherein the bearing receiving part (36) and the fastening part (37) are elastically connected to each other by at least one elastically deformable connecting element (38), and wherein the elastically deformable connecting element (38) comprises at least one sensor element (44) with which an elastic deformation of the elastically deformable connecting element (38) is determined, and wherein the elastic deformation is used to determine the cause of this elastic deformation. Force is inferred.

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