Unbalance measuring device, machining device, and method for calibrating the machining device, in particular the unbalance measuring device

Abstract

The present invention relates to an unbalance measuring device (U) comprising two mutually spaced workpiece holding devices (1, 2) for rotatably holding a workpiece (W), the unbalance of which is to be measured, and at least one sensor (3) for sensing vibration of the workpiece (W) during the rotation, wherein the workpiece holding devices (1, 2) each have a connection device (11 and 21, respectively) for stationary fastening and a workpiece holder (13 and 23, respectively) for rotationally holding a workpiece portion, wherein respective spring devices (12 and 22, respectively) are disposed between the connection devices (11 and 21, respectively) and the workpiece holders (13 and 23, respectively), wherein each spring device comprises a bar segment (121a), a first holder (121b) and a second holder (121c), wherein the bar segment (121a) is clamped, at respective ends thereof, into the first holder (121b) and into the second holder (121c) and / or the unbalance measuring device is equipped with an angular position sensor device (3a), comprising an angular position sensor (33a), for determining the angular position of the workpiece (W) on the workpiece holder (13), wherein the angular position sensor (33a) is connected to the workpiece holder (13). The present invention also relates to a machining device for a workpiece (W), comprising: a machining holder (5) for holding the workpiece (W), comprising a first retaining means (51), a second retaining means (53) and a drive means (52), the drive means (52) being designed to set the workpiece (W) into rotation, and the retaining means (51, 53) being designed to retain the workpiece (W); at least one machining means (6) for machining the workpiece (W); and an unbalance measuring device (U); wherein the drive means comprises a drive roller (52a) or a belt drive.

Description

[0001] Unbalance measuring device, machining device, and method for calibrating the machining device, in particular the unbalance measuring device

[0002] The present invention relates to an unbalance measuring device according to the preamble of claims 1 and 4, a machining device according to the preamble of claims 8 and 11, and a method for calibrating the machining device, in particular the unbalance measuring device according to the preamble of claim 13.

[0003] Machining equipment for machining rotationally symmetrical workpieces is well known. Machining processes on workpieces, particularly metal-cutting processes such as grinding, turning, etc., are carried out on such equipment.

[0004] Such machining facilities can be used, for example, to machine rotors for electrical machines, in particular electric motors.

[0005] A problem with rotors for electric motors arises from the fact that performance increases with increasing speeds, but with this the requirements for balancing quality and running characteristics increase.

[0006] For this purpose, for example, a method and a device for balancing a workpiece have become known from DE 10 2017 125 889 A1. In particular, a method for balancing a workpiece is proposed here, in which the workpiece is rotated about a rotational axis, the forces and / or moments and / or vibrations that arise due to an imbalance of the workpiece when the workpiece is rotated are measured, and material from the workpiece is removed to reduce the imbalance, and is characterized in particular in that the material is removed from the rotating workpiece during measuring or the workpiece is continuously rotated between measuring and removal.Furthermore, a device for balancing a workpiece is proposed here, comprising a clamping device for the workpiece and a rotary drive for rotating the workpiece about a rotational axis, comprising at least one sensor for measuring forces and / or moments and / or vibrations due to an imbalance of the workpiece during rotation of the workpiece and at least one machining means for removing material from the workpiece by the rotation of the workpiece, which is characterized in particular in that the machining means can be controlled on the basis of the signals from the sensor in such a way that the material can be removed to reduce the imbalance during rotation of the workpiece. Furthermore, an improved unbalance measuring device or machining device has become known from DE 10 2021 208 139 and PCT / EP2022 / 071127, respectively, which were unpublished at the time of this application. The content of these applications is incorporated in their entirety into the subject matter of this application.

[0007] Although a useful unbalance measuring device is proposed here, there is still a need for improvement, in particular with regard to simplifying the unbalance measuring device.

[0008] The object of the present invention is accordingly to propose an improved unbalance measuring device, in particular to propose an unbalance measuring device which can be constructed in a simplified manner.

[0009] According to the invention, this object is achieved by an unbalance measuring device having the characterizing features of claim 1. Because the spring device comprises a rod segment, as well as a first receptacle and a second receptacle, wherein the rod segment is clamped at each end into the first receptacle and the second receptacle, a simplified spring device and thus a simplified unbalance measuring device can be provided. The rod segment can be designed, for example, as a simple elastic rod without its own connection means. The rod segment can be attached to the connection device or the workpiece holder by suitable receptacles.

[0010] Further advantageous embodiments of the proposed invention emerge in particular from the features of the subclaims. The subject matter and features of the various claims can, in principle, be combined with one another in any desired way.

[0011] In an advantageous embodiment of the invention, it can be provided that the first receptacle is connected to the connection device and the second receptacle is connected to the workpiece holder, in particular by means of screws.

[0012] In a further advantageous embodiment of the invention, it can be provided that the rod segment is designed as a rod-shaped profile.

[0013] Another object of the present invention is to provide an improved

[0014] To propose an unbalance measuring device, in particular to propose an unbalance measuring device with which a better angular position detection of the workpiece can be enabled.

[0015] According to the invention, this object is achieved by an unbalance measuring device having the characterizing features of claim 4. Because the unbalance measuring device is equipped with an angular position sensor device, comprising an angular position sensor, for determining the angular position of the workpiece on the workpiece holder, wherein the angular position sensor is connected to the workpiece holder, a more precise measurement of the angular position of the workpiece can be performed with fewer disturbances, since the angular position sensor oscillates with the workpiece holder. A smaller distance to the workpiece can also be achieved.

[0016] Further advantageous embodiments of the proposed invention emerge in particular from the features of the subclaims. The subject matter and features of the various claims can, in principle, be combined with one another in any desired way.

[0017] In an advantageous embodiment of the invention, the angular position sensor device can comprise a bracket, a connection for the angular position sensor, and the angular position sensor accommodated by the connection. The connection provided for the angular position sensor can ensure replacement of the sensor, for example, during maintenance. The bracket can, for example, be adapted to the shape of the workpiece, so that a small distance between the sensor and the workpiece can be achieved.

[0018] In a further advantageous embodiment of the invention, the bracket can be shaped like a circular segment. This circular shape allows the sensor to be brought close to the workpiece, which is usually a rotationally symmetrical part, in particular a rotor or rotor shaft of an electrical machine.

[0019] In a further advantageous embodiment of the invention, it can be provided that the bracket comprises a connection for pivotable fastening to the workpiece holder, as well as a slot for fastening the connection for the angular position sensor, wherein the connection for the angular position sensor is fastened to the bracket by means of a screw, wherein the screw is inserted through the slot. This allows a very individual position of the angular position sensor to be set along the slot. The angular position sensor or its housing can be designed such that it can be fixed directly on or in the slot. Since the slot is usually provided in the bracket, the connection and thus the angular position sensor can be moved along the bracket and fixed in a suitable position. This further improves the adaptability of the angular position sensor to the workpiece.

[0020] A further object of the present invention is to propose an improved machining device for a workpiece, in particular to propose a machining device which has an improved drive means for setting the workpiece in rotation.

[0021] According to the invention, this object is achieved by a machining device having the characterizing features of claim 8 or 11. Because the drive means comprises a drive roller which can be brought into contact with the workpiece to be driven, a drive means can be provided which can set the workpiece in rotation, keep it in rotation or brake it, but at the same time equally permit an alternating movement, i.e. oscillation, of the workpiece or the workpiece holder and / or enable protection against the workpiece being lifted off. The drive means, in this case the drive roller, should ideally be designed to act in the middle of the workpiece and perpendicular to the axis of rotation, in principle at the center of gravity of the workpiece. The slip of the drive roller relative to the workpiece can be influenced or adjusted via the force when the drive roller is pressed against the workpiece.When accelerating or decelerating the workpiece, the contact force or pressure force can usually be greater than during measurement. During measurement, as little force as possible should be applied to the workpiece, especially to avoid influencing the vibration, measurement, and / or damping.

[0022] Further advantageous embodiments of the proposed invention emerge in particular from the features of the subclaims. The subject matter and features of the various claims can, in principle, be combined with one another in any desired way.

[0023] In an advantageous embodiment of the invention, the drive roller can be equipped with a friction lining. The friction lining, or a correspondingly designed friction lining, contributes to the creation of a defined slip between the drive roller and the workpiece. In an advantageous embodiment, the drive roller can be a grinding wheel, in particular the grinding wheel used for balancing or for material removal during balancing.

[0024] In a further advantageous embodiment of the invention, the drive means can comprise a pivoting device configured to selectively press the drive roller onto the workpiece or lift it off the workpiece. Using the pivoting device, the drive roller can be selectively placed onto the workpiece or removed from the workpiece. The pivoting device is also suitable for permitting alternating movement of the workpiece or the workpiece holder. The drive roller or the pivoting device can also prevent or counteract the lifting of the rotating workpiece in the workpiece holder.

[0025] Alternatively, to achieve the object outlined above, it can also be provided according to claim 11 that the drive means comprises a belt drive, wherein the belt drive comprises a belt that can be pressed onto the workpiece to be driven.

[0026] The belt drive can set the workpiece in rotation, keep it in rotation or slow it down, but at the same time allow an alternating movement, i.e. oscillation, of the workpiece or the workpiece holder and / or provide protection against the workpiece lifting off. The drive means, in this case the belt, should ideally be designed to act in the middle of the workpiece and perpendicular to the axis of rotation, basically at the center of gravity of the workpiece. The slip of the drive roller relative to the workpiece can be influenced or adjusted via the force when the belt or belt drive is pressed against the workpiece. When accelerating or braking the workpiece, the contact force or pressure force can usually be greater than during measurement. During measurement, as little force as possible should be applied to the workpiece, particularly to avoid influencing the oscillation, measurement and / or damping.In addition, the belt can prevent the rotor shaft from lifting off the device or the device's rollers when measuring the unbalance.

[0027] Further advantageous embodiments of the proposed invention emerge in particular from the features of the subclaims. The subject matter or features of the various claims can in principle be combined with one another as desired. In an advantageous embodiment of the invention, it can be provided that the belt drive comprises a drive roller, two tension rollers and the belt. In particular, the belt tension and thus the contact pressure on the workpiece can be adjusted via the tension rollers. For example, it can be provided that a lot of force is applied to the workpiece by the belt when the workpiece is initially driven or brought up to speed. It can also be provided that the contact pressure is reduced during the measuring process or when the speed is maintained, in particular by relaxing the belt. A certain amount of slippage can occur between the belt and the workpiece.In principle, the entire belt drive can also be raised relative to the workpiece.

[0028] In an advantageous embodiment, it can be provided that the belt is a grinding belt or sanding belt.

[0029] A further object of the present invention is to propose an advantageous method for calibrating the machining device, in particular the imbalance measuring device. In particular, the method is intended to counteract or eliminate an angular error of the workpiece during clamping.

[0030] According to the invention, this object is achieved by a method for calibrating the machining device, in particular the unbalance measuring device, with the characterizing features of claim 13. By means of the method steps proposed according to claim 13, an angular error of the workpiece during clamping can be counteracted or eliminated.

[0031] Further advantageous embodiments of the proposed invention emerge in particular from the features of the subclaims. The subject matter or features of the various claims can, in principle, be combined with one another as desired. Further features and advantages of the present invention will become clear from the following description of preferred embodiments with reference to the accompanying drawings.

[0032] Fig. 1 shows an unbalance measuring device in a side view;

[0033] Fig. 2 an unbalance measuring device in a view from above;

[0034] Fig. 3 a section AA of an unbalance measuring device;

[0035] Fig. 4 a section BB of an unbalance measuring device;

[0036] Fig. 5 is a perspective view of an unbalance measuring device;

[0037] Fig. 6 is a perspective view of an unbalance measuring device;

[0038] Fig. 7 shows an unbalance measuring device in a side view with an indication of a direction of movement;

[0039] Fig. 8 shows a processing device in a schematic representation;

[0040] Fig. 9 shows an example of a workpiece, in particular the rotor shaft of an electrical machine;

[0041] Fig. 10 shows a method step I of a method for measuring the unbalance and machining a workpiece in a schematic diagram;

[0042] Fig. 11 shows a method step II of a method for measuring the unbalance and machining a workpiece in a schematic diagram;

[0043] Fig. 12 shows a method step III of a method for measuring the unbalance and machining a workpiece in a schematic diagram;

[0044] Fig. 13 shows a method step IV of a method for measuring the unbalance and machining a workpiece in a schematic diagram;

[0045] Fig. 13a shows an alternative method step IV of a method for measuring the unbalance and machining a workpiece in a schematic diagram;

[0046] Fig. 13b shows an alternative method step IV of a method for measuring unbalance and machining a workpiece in a schematic diagram; Fig. 13c shows an alternative method step IV of a method for measuring unbalance and machining a workpiece in a schematic diagram;

[0047] Fig. 14 shows a method step V of a method for measuring the unbalance and machining a workpiece in a schematic diagram;

[0048] Fig. 15 shows an unbalance measuring device with a spring device comprising a rod segment, in a view from the front;

[0049] Fig. 15a an unbalance measuring device with an alternative design of a

[0050] Spring device comprising a rod segment, in a front view;

[0051] Fig. 15b an unbalance measuring device with an alternative design of a

[0052] Spring device, including other spring configurations, in a front view;

[0053] Fig. 16 shows an unbalance measuring device with a spring device comprising a rod segment, in a perspective view;

[0054] Fig. 16a shows an unbalance measuring device with an alternative embodiment of a spring device, comprising a rod segment, in a perspective view;

[0055] Fig. 17 shows an unbalance measuring device with an angle sensor device in a perspective view;

[0056] Fig. 18 shows an unbalance measuring device with an angle sensor device in a perspective view;

[0057] Fig. 18a shows an unbalance measuring device with an angle sensor device and a drive roller placed on the workpiece in a perspective view;

[0058] Fig. 19 shows a detail of a machining device with an unbalance measuring device with a drive roller placed on the workpiece in a front view;

[0059] Fig. 20 shows a detail of a machining device with an unbalance measuring device with a drive roller placed on the workpiece and a pivotable holder, in particular with two indicated positions of the drive roller;

[0060] Fig. 21 shows a detail of a machining device with an unbalance measuring device with a drive roller lifted from the workpiece and a pivotable holder; Fig. 22 shows a detail of a machining device with an unbalance measuring device with a drive roller placed on the workpiece and a pivotable holder, in particular with two indicated positions of the drive roller;

[0061] Fig. 22a is an enlarged detailed view of a drive roller on a workpiece in two positions;

[0062] Fig. 23 a machining device with an unbalance measuring device with a belt drive mounted on the workpiece;

[0063] Fig. 24 a machining device with an unbalance measuring device with a belt drive mounted on the workpiece;

[0064] Fig. 25 a machining device with an unbalance measuring device with a belt drive mounted on the workpiece;

[0065] Fig. 26 a workpiece with two areas on one side (and two further areas on the other side) on a machining device with an unbalance measuring device;

[0066] Fig. 26a a workpiece with two areas on one side (and two further areas on the other side) on a machining device with an unbalance measuring device;

[0067] Fig. 27 a workpiece with several areas on one side (and further areas on the other side) on a machining device with an unbalance measuring device;

[0068] Fig. 28 a workpiece on a machining device with an unbalance measuring device to illustrate the balancing of the workpiece, in particular by removing material at calculated points.

[0069] The following reference symbols are used in the figures:

[0070] U Unbalance measuring device

[0071] R rotation axis

[0072] Hl vertical axis

[0073] H2 vertical axis

[0074] W Workpiece, especially rotor shaft Z Shaft stub / pin

[0075] B sheet package

[0076] D thrust washer

[0077] DV data processing facility

[0078] For supporting force

[0079] Fa Manager

[0080] EL installation length / clamping length rod segment

[0081] S dirt protection

[0082] E setup tool

[0083] N Reference surface for material removal

[0084] Bl first area (first axial position)

[0085] B2 further area (first axial position)

[0086] Bl ' first area (second axial position)

[0087] B2' further area (second axial position)

[0088] ml first mass

[0089] M2 second mass

[0090] 1 first workpiece holding device

[0091] 2 second workpiece holding device

[0092] 3 Sensor, especially acceleration sensor

[0093] 4 machining table

[0094] 5 Machining recording Machining equipment

[0095] Quick release

[0096] stop

[0097] Adjustment of the stop 9

[0098] Connection device

[0099] Spring device

[0100] Workpiece holder

[0101] Connection device

[0102] Spring device

[0103] Workpiece holder

[0104] Adjustment spring device first holding means

[0105] Drive means second holding means

[0106] bracket

[0107] role

[0108] Spring, in particular leaf spring 22 Swivel arm 23 Swivel arm 31 First roller 32 Second roller 21 Spring, in particular leaf spring 22 Swivel arm 23 Swivel arm 31 First roller 32 Second roller a Angular position sensor device 1a Bracket 2a Connection 3a Angular position sensor 2a Drive roller 2b Belt drive 11a Connection 12a Slot 13a Stop 21a Rod segment 21b Holder 21c Holder 121d Adjustment of the holder 121b

[0109] 121e Scale for adjustment 121d

[0110] 121f; f' electromechanical adjustment

[0111] 221a rod segment

[0112] 221b Recording

[0113] 221c Recording

[0114] 221f, f' adjustment

[0115] 321a spring element, coil spring

[0116] 321b Spring element holder 321a

[0117] 321c Spring element holder 321a

[0118] 321d adjustment for 321a

[0119] 421a spring element, bow spring

[0120] 421c Spring element holder 321a

[0121] 421d adjustment for 321a

[0122] 521a holder

[0123] 522a Drive, in particular hydraulic cylinders

[0124] 521b drive roller

[0125] 522b tension pulley

[0126] 523b tension pulley

[0127] 524b belt

[0128] Features and details described in connection with a method naturally also apply in connection with the device according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other. Furthermore, a method according to the invention that may be described can be carried out with the device according to the invention.

[0129] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a" and "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It will also be understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of the recited features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed elements.

[0130] Reference is made below to Figs. 1 to 8. Figs. 1 to 8 schematically illustrate an unbalance measuring device and a processing device, respectively, as described in DE 10 2021 208 139 and PCT / EP2022 / 071127.

[0131] An unbalance measuring device U comprises a first workpiece holding device 1, a second workpiece holding device 2 and a sensor 3 for determining an unbalance of a rotating workpiece W.

[0132] The first workpiece receiving device 1 comprises a connecting device 11 for detachable connection to a machining table 4. Furthermore, the first workpiece receiving device 1 comprises a workpiece holder 13. The workpiece holder 13 is configured to rotately receive a section of the workpiece W.

[0133] The second workpiece receiving device 2 comprises a connecting device 21 for detachable connection to the machining table 4. Furthermore, the second workpiece receiving device 2 comprises a workpiece holder 23. The workpiece holder 23 is configured to rotately receive a section of the workpiece W.

[0134] The workpiece holding devices 1, 2 are arranged at a distance from one another so that a workpiece W can be arranged between the workpiece holding devices. In this case, it is preferably provided that the ends of the workpiece, in the example here, the shaft stubs Z of a rotor shaft, are held in the workpiece holders 13, 23. In this respect, the workpiece holders 13, 23 or the held workpiece W form a rotation axis R. The workpiece W can therefore be held in the workpiece holders 13, 23 between the two workpiece holding devices 1, 2 so that it can rotate about the rotation axis R. Preferably, the workpiece holding devices 1, 2 form an axial limitation by suitable selection of the distance so that the workpiece W cannot be moved or can only be moved slightly between the workpiece holding devices 1, 2. In the figures, a vertical axis Hl orH2 is shown, which preferably runs perpendicularly from the machining table 4 through the rotation axis R.

[0135] It can be seen that a spring device 12 or 22 is arranged between the connecting device 11 or 21 and the workpiece holder 13 or 23, which is designed so that the workpiece holder 13 or 23 can be moved relative to the connecting device 11 or 21 against the force of a spring 121 or 221 in a direction perpendicular or substantially perpendicular to the rotation axis R. Preferably, the first workpiece holder 1 and / or the second workpiece holder 2 is equipped with a spring device 12, 22.

[0136] The spring device 12 therefore basically enables an evasive movement of the workpiece holder 13 or 23 and the stationary connecting device 11 or 21, the direction of which is predetermined. As a result, vibration of a rotating workpiece W held by the unbalance measuring device U, which vibration is caused by an imbalance, can basically be transmitted to the workpiece holders 13 or 23. However, the workpiece holders 13 or 23 are not permanently connected to the connecting devices 11 or 21, so that they can form a defined oscillating system together with the workpiece W. With knowledge of the dynamic properties of this system, the vibrations of the workpiece W that are actually of interest can be calculated using the vibrations of the overall system comprising the workpiece W and the workpiece holders 13 or 23. For this purpose, it is provided that at least one workpiece holder, preferably both workpiece holders 13 or23, are equipped with a corresponding sensor 3, in particular an acceleration sensor, which in turn are connected to a data processing device DV.

[0137] It is further preferably provided that the spring device 12 or 22 comprises a leaf spring 121 or 221. The leaf spring is preferably oriented in the direction of the vertical axis H1 or H2.

[0138] In the illustrated unbalance measuring device U, decoupling is preferably realized via a mechanical spring device 12 or 22. However, the corresponding spring effect can also be achieved via other measures, such as hydraulic or pneumatic components.

[0139] It is further preferably provided that the spring device comprises a first pivot arm 122 or 123 and a second pivot arm 222 or 223 between the connecting device 11 or 21 and the workpiece holder 13 or 23, wherein the pivot arms are arranged in an articulated manner both on the connecting device and on the workpiece holder. The joint axes of the pivot arms 122, 123 or 222, 223 are preferably arranged parallel to the rotation axis R. This arrangement results in a connection in the manner of a non-rotatable flat rotary joint gear. In this respect, the pivot arms 122, 123 or 222, 223 force the respective workpiece holder 13 or 23 onto an approximately rectilinear, actually slightly circular, path of movement. However, the linear movement component is primarily important. The spring device 12 or 22, in particular the spring 121 or 221, is arranged between the connecting device 11 or 21 and the workpiece holder 13 or23 is arranged such that the workpiece holder 13 or 23 is always moved back to a central position in which the pivot arms 122, 123 or 222, 223 are aligned perpendicular to the machining table or parallel to the vertical axes H1 or H2. The spring 121 or 221, in particular a leaf spring, is preferably aligned congruently with the vertical axis, in particular parallel to the vertical axis H1 or H2. The approximate direction of movement is illustrated by arrows, in particular in Fig. 14.

[0140] It is further preferably provided that the workpiece holders 13 and 23 of the unbalance measuring device U each comprise a first rotatable roller 131 and 231, respectively, and a second rotatable roller 132 and 232, respectively, which form the holder for a section of the workpiece W, for example the shaft stub of a rotor shaft, between them. The axis of rotation of the rollers 131, 132, 231, 232 is preferably aligned parallel to the axis of rotation R. It is accordingly provided that the workpiece ends are received between the rollers 131 and 132 or 231 and 232, whereby the roller spacing is, however, smaller than the diameter of the workpiece end to be received. The received workpiece end can therefore be supported by the two rollers.

[0141] In the embodiments according to Fig. 1 to Fig. 8, it is also provided that the unbalance measuring device U is equipped with two quick-release fasteners 7. As will be explained further below, the quick-release fastener 7 can also be omitted or implemented by other measures.

[0142] The quick-release fastener 7 essentially comprises a pivotable bracket 71. The bracket 71 has an L-shape. The pivot axis is aligned parallel to the axis of rotation. The quick-release fastener further comprises a rotatable roller 72. The axis of rotation of the roller is aligned parallel to the axis of rotation. The workpiece is already held in the direction of gravity in the workpiece holders 13 or 23, in particular between the rollers 131, 132 or 231, 232. With the quick-release fastener 7, the holder can be closed to a certain extent by the roller 72 of the quick-release fastener 7 resting on the workpiece end from above. In this case, the workpiece end is surrounded by three rollers and can therefore no longer escape. By pivoting or folding open the quick-release fasteners 7, the holder can be released accordingly and the workpiece W can be removed.The quick-release fastener 7 can be operated automatically, in particular hydraulically or pneumatically.

[0143] A machining device for a workpiece W essentially comprises a machining holder 5 for receiving the workpiece, comprising a first holding means 51, a second holding means 53 and a drive means 52, wherein the drive means 52 is configured to set the workpiece W in rotation, wherein the holding means 51, 53 are configured to hold the workpiece W. Furthermore, the machining device comprises at least one machining means 6 for machining the workpiece W, as well as an unbalance measuring device U. The unbalance measuring device U is preferably the described unbalance measuring device U.

[0144] The machining means 6 can be, for example, a milling, turning, or grinding device. Other machining devices, particularly for machining workpieces, particularly metal ones, are also conceivable. In particular, depending on the selected machining means 6, the direction in which the selected machining means 6 is brought to the workpiece W can vary.

[0145] The machining fixture 5 is preferably connected to the machining table 4 or mounted thereon. The machining table 4 is, for example, fixedly mounted. However, the machining table 4 can also be designed to be movable, such that the unbalance measuring device U mounted on the machining table 4, in particular the workpiece holding devices 1, 2, can be moved toward the machining fixture 5, in particular the holding means 51, 53 or the workpiece W. The unbalance measuring device U can therefore also be fed to the workpiece W and / or the machining fixture 5, in particular the holding means 51, 53, or the held workpiece W, can be fed to the unbalance measuring device U.For example, the machining table 4 can also be designed in several parts, in particular such that a first part of the machining table 4 forms the holding means 51, 53 and the drive means 52 and a further part of the machining table 4 carries the unbalance measuring device U, in particular unbalance measuring device U.

[0146] In principle, forces and moments can be transferred to the machining table 4. The machining fixture 5 can be directly connected to the machining table. The workpiece fixtures 13 and 23 are indirectly connected to the machining table 4 via the spring devices 12 and 22, respectively. The stop 9 limits the deflection of the workpiece fixtures 13, 23 and the spring devices 12, 22 and can be adjusted or adapted using the adjustment 10.

[0147] The holding means 51, 53 are fundamentally designed to establish a detachable, in particular quickly detachable, connection with the workpiece W. The holding means 51 are designed for holding, in particular for a holder suitable for machining with the machining means 6. The holding means 51, 53 are connected to a transport mechanism (not shown here) with which, for example, a transfer or positioning of a held workpiece can be carried out, for example, placing it on or removing it from the unbalance measuring device U, in particular the workpiece holding devices 1, 2.

[0148] For example, Oldham couplings with corresponding cones or truncated cones, which can engage, for example, hollow-cylindrical shaft ends of a workpiece, in particular a rotor shaft, can be considered as holding means 51, 53, or the holding means can comprise the aforementioned components. The holding means 51, 53 can also be corresponding form-locking elements, or the holding means can comprise the aforementioned components, which can releasably establish a form-locking connection to the workpiece W, in particular to the shaft stubs Z, for example according to the key-lock principle.

[0149] The drive means 52 can be, for example, an electric motor or a stepper motor, with which the workpiece W can be set in rotation or with which a predetermined angular position of the workpiece W can be approached. Further alternative drive means will be described later.

[0150] Further details of the present invention emerge in particular from an exemplary description of the method according to the invention.

[0151] A basic method for balancing and / or machining a workpiece, in particular a rotor shaft, using a machining device, in particular an imbalance measuring device, will be explained below. It is understood that only a few selected method steps are presented here, as they are helpful for understanding the method according to the invention. The method may include further steps or intermediate steps known to those skilled in the art.

[0152] A rotationally symmetrical workpiece W, such as a rotor shaft of an electric machine, is conceivable as the workpiece. Such a rotor shaft is shown, for example, in Fig. 9. In particular, the rotor shaft W with end journals Z, as well as the laminated core B (shown in dashed lines) and the thrust washers D (shown in dotted lines) are shown.

[0153] In Fig. 10, a rotor shaft W is shown schematically, which is driven by the machining

[0154] 5, in particular by the holding means 51, 53. The workpiece W has not yet been inserted into or picked up by the workpiece holding devices 1, 2 of the unbalance measuring device U.

[0155] First, the workpiece W is subjected to conventional machining by the machining tool

[0156] 6, for example grinding or machining of the workpiece W. However, this processing is not for balancing the workpiece W, but for general machining.

[0157] Fig. 11 schematically shows a machining process for the workpiece W, in particular the bearing points on the rotor shaft. In addition, defined reference surfaces or reference contours are formed, from which material is removed during balancing. Since these surfaces or geometries are formed in one setup with the bearing points, these reference surfaces are highly precisely coaxial with the bearing point L. For this purpose, the machining means 6, for example a grinding device, is used. A steady rest or the like is also possible to absorb and / or support grinding forces. A different machining situation or a different tool is shown in dashed lines.

[0158] Preferably, the drive means 52 sets the workpiece W in rotation during this processing.

[0159] Fig. 12 schematically shows ground bearing points L of the workpiece W. It is also shown how the machining means 6 is no longer in use or has been moved away. The machined, or at least partially machined, workpiece W has been brought to the workpiece holding devices 1, 2 of the unbalance measuring device U by means of the machining holder, in particular the holding means 51, 53, and has been placed on the workpiece holding devices 1, 2, in particular the workpiece holders 13, 23. Alternatively or additionally, it can also be provided that the workpiece holding devices 1, 2 of the

[0160] The unbalance measuring device U is moved towards the partially machined workpiece, so to speak the unbalance measuring device U is moved to the workpiece W. The holding means 51, 53 are separated from the workpiece W, alternatively only one holding means is separated from the workpiece W, preferably the holding means 53 is separated, which is arranged on the opposite side of the drive 52. The drive means 52, however, is connected to the workpiece W. In particular, radial and axial guidance of the workpiece W by the workpiece holding devices 1, 2 is provided. For example, the axial guidance of the workpiece W in the unbalance measuring device U can be achieved by means of a resilient element. This resilient element can, for example, apply the axial force Fa, guide the workpiece into an axial position and guide it when the drive or holding means 52, 53 are separated from the workpiece W.Preferably, the resilient element has a friction-reducing coating or rollers or the like. In particular, this resilient element axially loads and guides the workpiece W and, for example, engages an edge of the workpiece W. The forces exerted by the workpiece holding devices 1, 2 on the workpiece are schematically shown by way of example in Figure 13 by the stronger arrows, with radial support forces Fr and axial guide forces Fa being shown in particular.

[0161] It can be provided that the workpiece W is additionally secured against falling out with the quick-release fastener 7 on the workpiece holding devices or the workpiece holders.

[0162] The drive means 52 brings the workpiece W to a rotational speed, in particular to a balancing speed. Balancing speed is understood here as a rotational speed of the workpiece W at which a measurement of the imbalance is to be performed. This depends in particular on the component to be balanced and its subsequent operating speeds. For the precise angular support of the workpiece W, the angular position of the workpiece W can preferably be determined using sensors and references formed / attached to the workpiece W.

[0163] Fig. 13 schematically shows how the drive means 52 has been decoupled after reaching the balancing speed. The drive is still engaged with the workpiece. The workpiece W thus rotates freely in the unbalance measuring device U, in particular in the workpiece holders 13, 23. Decoupling from all machine parts, such as headstocks, steady rests, tailstocks, tools, etc., is advantageous for the measuring process. This preferably ensures that the measurement is not influenced by other rotating bodies and their masses or their vibration behavior. The mounting of the workpiece W on the workpiece holder devices 1, 2 and the decoupling of the drive means 52 or the holding means 51 can overlap.

[0164] Fig. 13a schematically shows an alternative embodiment in which the workpiece W is still engaged with the drive means 52, but the holding means 51, 53 have been uncoupled or separated. The workpiece W thus rotates freely in the unbalance measuring device U, in particular in the workpiece holders 13, 23, and can nevertheless be held at the desired speed or brought to the desired speeds. Advantageously, the drive means 52 is engaged with the workpiece W by means of an Oldham coupling, whereby the drive influences on the workpiece W can be minimized. Decoupling from the machine parts, such as headstocks, steady rests, tailstocks, tools, etc. is advantageous for the measuring process. This preferably ensures that the measurement is not influenced by other rotating bodies and their masses or their vibration behavior.The reception of the workpiece W on the workpiece receiving devices 1, 2 and the decoupling of the drive means 52 or the holding means 51 can overlap.

[0165] The workpiece W rotates at the desired speed, in particular the balancing speed. The unbalance is measured using sensor 3(s). During the measurement, the speed can decrease or pass through a predetermined speed range. The measurement results are transmitted to the data processing device DV. The data processing device DV calculates the measures to eliminate or at least reduce the unbalance to a technically acceptable level. The data processing device DV then subsequently also controls the machining tool 6.

[0166] Fig. 13b schematically shows an alternative embodiment in which the workpiece W is not engaged with the drive means 52 and the holding means 51, 53 have also been uncoupled or separated. The workpiece W thus rotates freely in the unbalance measuring device U, in particular in the workpiece holders 13, 23, and can be held at the desired speed or brought to the desired speed (accelerated or decelerated) by the drive means, which comprises, for example, a drive wheel 52a or a drive belt 52b. Advantageously, only the drive means 52 is engaged with the workpiece W, whereby the drive influences on the workpiece W can be minimized. The drive wheel 52a or the drive belt 52b preferably engage at the center of gravity of the workpiece W. Other or further drive means or points of engagement are shown in dashed lines. The decoupling from the machine parts, such asHeadstocks, steady rests, tailstocks, tools, etc. are advantageous for the measuring process. This preferably ensures that the measurement is not or only minimally influenced by other rotating bodies and their masses or their vibration behavior. The mounting of the workpiece W on the workpiece holding devices 1, 2 and the decoupling of the drive means 52 or the holding means 51 can overlap.

[0167] Fig. 13c schematically shows an alternative embodiment in which the workpiece W is not engaged with the drive means 52 and the holding means 51, 53 have also been uncoupled or separated. The workpiece W thus rotates freely in the unbalance measuring device U, in particular in the workpiece holders 13, 23, and can be held at the desired speed or brought to the desired speeds (accelerated or decelerated) by the drive means, which, for example, comprises a drive wheel 52a, in particular a machining means 6. The machining means 6 can, for example, be the grinding wheel 6 used to create the unbalance. Advantageously, the workpiece W is held here by the holding means 51, 53, whereby the forces occurring are reliably absorbed. The drive wheel 52a or the grinding wheel 6 preferably acts at the center of gravity of the workpiece W. However, other or additional points of action are also shown in dashed lines.These arise, for example, from the previous machining of the workpiece. The grinding wheel 6 rotates the workpiece W to a desired speed, then the holding means 51, 53 are separated from the workpiece, and the workpiece is guided exclusively through the workpiece holding devices 1, 2, and the imbalance is measured. The mounting of the workpiece W on the workpiece holding devices 1, 2 and the decoupling of the holding means 51, 53 can overlap.

[0168] For machining the bearing points L and the reference surfaces for balancing, the grinding wheel is already in contact with the workpiece W. If it then rotates the workpiece W to the desired speed, as in this embodiment, the cycle time for machining and balancing the workpiece W can be reduced. In addition, the decoupling from the machine parts, such as headstocks, steady rests, tailstocks, tools, etc. is advantageous for the measuring process. This preferably ensures that the measurement is not or only slightly influenced by other rotating bodies and their masses or their vibration behavior. The holding of the workpiece W on the workpiece holding devices 1, 2 and the decoupling of the drive means 52 or the holding means 51 can overlap.

[0169] In each case, the workpiece W rotates at the desired speed, a speed ramp, in particular the balancing speed. The unbalance is measured using sensor 3(s). During the measurement, the speed can decrease or pass through a predetermined speed range. The measurement results are transmitted to the data processing device DV. The data processing device DV calculates the measures to eliminate or at least reduce the unbalance to a technically acceptable level. The data processing device DV then subsequently also controls the machining tool 6.

[0170] Fig. 14 schematically illustrates how the measures calculated by the data processing device DV are implemented, in particular how material is removed at predetermined locations on the workpiece W. These predetermined locations are preferably reference surfaces N formed with a high degree of accuracy, in particular with a low coaxiality error relative to the bearing point L. These reference surfaces can be formed, for example, on the flange Z, the laminated core B, the shaft body of the workpiece W, or the thrust washers D. For this purpose, the same machining means 6 as for conventional machining, as well as a separate machining means, can be used. Furthermore, it is preferably provided that the workpiece W is removed from the unbalance measuring device U, in particular by the holding means 51.It can also be provided that the workpiece W is now reconnected to the drive means 52, thereby rotating it or moving it to predetermined angular positions. If the quick-release fastener 7 was previously used, it has been opened again.

[0171] The material removed to influence the imbalance of the workpiece W, in particular to at least partially reduce the circumference, in particular to shape the circumference of the workpiece W, can, for example, be removed from the workpiece in such a way that a flat spot, a free-form surface or a circular segment surface is created thereon.

[0172] The unbalance measuring device U can also be separately equipped with the data processing device DV, the processing means 6 for the unbalance processing of the workpiece W, as well as the processing holder 5, comprising holding means 51, 53 for holding the workpiece W and the drive means 52 for setting the workpiece W in rotation.

[0173] Improvements to the machining device, in particular the unbalance measuring device U, are proposed below.

[0174] Reference is made below to Figs. 15, 15a, 15b and 16, 16a.

[0175] Here, in particular, an alternative embodiment of a spring device 12 is shown, comprising a rod segment 121a, as well as a first receptacle 121b and a second receptacle 121c. The rod segment 121a is clamped at its end into the first receptacle 121b and the second receptacle 121c. The first receptacle 121b is correspondingly connected to the connection device 11 and the second receptacle 121c is fastened to the workpiece holder 13, in particular by means of screws. The rod segment 121a is designed as a rod-shaped profile. It has elastic, in particular flexurally elastic properties, which are comparable to those of a leaf spring, but can be manufactured much more easily. The rod segment can be bent accordingly. The rod segment or receptacles on the other side are correspondingly identified with the reference numerals 221a, 221b and 221c. The rod segment is accommodated, for example, in such a way that it has an installation length EL oran effective bending length.

[0176] Figure 15a shows that the effective bending length EL or the installation length EL can be changed. For this purpose, for example, the holder 121b can be fastened relatively axially along the rod element 121 by means of an adjustment 121d, such as an elongated hole or individual threaded holes. The changed bending length or installation length changes the elastic spring behavior of the rod element 121a. By means of an adaptable or changeable spring behavior, the device can be adapted to different imbalances and workpieces W. The stop 9 prevents overloading of the spring device 12, 121a, 221a. By means of the adjustment 10, the stop 9 can also be adapted to the different conditions. A scale 121e, 221e facilitates the correct adjustment of the holder 121b, 221b on both sides of the device U, 1. The spring behavior of the rod element can be influenced or changed by material and geometry.

[0177] Figure 15b shows a further embodiment in which the effective bending length EL or the installation length EL is variable. For this purpose, an electromechanical adjuster 121f can be used, for example. The various installation lengths EL or the various effective bending lengths are schematically represented here by dashed lines. An electromechanical adjuster 121f can, for example, comprise a linear drive and change the support or fastening of the spring device or the rod element 121a, 221a.

[0178] Figure 15c shows an alternative embodiment in which the spring device 12 comprises a horizontally oriented spring, for example, a helical spring 321a, in particular a helical spring with progressive behavior. In the helical spring 321a, the spring behavior can be adjusted or changed by means of a variable preload, in particular by means of an adjuster 321d. Furthermore, Figure 15c shows, by way of example, a torsion spring or a leg spring 421a. The spring behavior of such a leg spring can also be influenced by the preload, for example, by means of an adjuster 421d.

[0179] Figure 16a shows an alternative embodiment of an unbalance measuring device with an alternative embodiment of a spring device, comprising a rod segment, in a perspective view. The deflection of the workpiece holder 23 can be limited by means of the stop 9. The stop 9 can be adjusted by means of an adjustment 10. The adjustment 221f enables the adaptation of the spring behavior of the spring device, in particular of the rod segment 221a, to expected vibrations of the workpiece holder 23 or the unbalance of the workpiece W that are to be expected or have occurred during a measurement. Furthermore, the adjustment 221f can be adjusted to and thus to the expected or

[0180] Reference is made below to Figs. 17 and 18.

[0181] Here, in particular, an angular position sensor device 3a for determining the angular position of the workpiece on the workpiece holder 13 is shown.

[0182] The angular position sensor device 3a essentially comprises a bracket 31a and a connection 32a for an angular position sensor 33a.

[0183] The bracket 31a as such preferably has the shape of a circular segment and is curved accordingly. Furthermore, the bracket 31a comprises a connection 311a for pivotable attachment to the workpiece holder 13, as well as an elongated hole 312a for attaching the connection 32a for the angular position sensor 33a. The connection 311a for pivotable attachment to the workpiece holder 13 can, for example, be designed as a screw that is inserted through a corresponding opening in the bracket 31a. The pivot axis of the bracket 31a runs parallel to the rotational axis R of the workpiece. The angular position sensor device 3a, in particular the bracket 31a, can further be equipped with a stop 313a for limiting the pivot angle of the bracket 31a.

[0184] The connector 32a for the angular position sensor 33a can be attached to the bracket 31a by means of a screw, whereby the screw can be inserted through the elongated hole 312a. In this way, the connector 32a can be moved along the bracket 31a and secured at a suitable location. The connector 32a can thus be moved essentially along a semicircular path and secured at a suitable location.

[0185] This results in improved guidance for the angular position sensor, in particular for determining the angular position of the workpiece. A further advantage lies in the fact that the angular position sensor 33a can be positioned or displaced relative to the rotation axis and along the rotation axis. This advantageously results in a shorter distance to the workpiece, less interference, and more precise measurement. The angular position sensor 33a can also oscillate with the workpiece holder 13. Fig. 17 shows the angular position sensor device 3a, in particular the connection 32a, without an inserted angular position sensor 33a. Fig. 18 shows the angular position sensor device 3a, in particular the connection 32a, with the inserted angular position sensor 33a.

[0186] Reference is made below to Fig. 19 to Fig. 22a and Fig. 23 to 25.

[0187] In the following, alternative drive means (drive roller 52a, belt drive 52b) are presented, which are designed to set the workpiece in rotation.

[0188] The drive means should advantageously set the workpiece in rotation and provide protection against the workpiece being lifted off. With regard to the function of the drive, acceleration, deceleration, and maintaining speed are also mentioned. Preferably, embodiments of the drive means should be proposed in which the workpiece is driven by friction.

[0189] The drive means should ideally be designed to act in the center of the workpiece and perpendicular to the axis of rotation, in principle at the shear point of the workpiece.

[0190] The drive means should ideally also be designed to allow alternating movements of the rotor shaft, in particular a vibration of the workpiece holder 13. In this case, as little force as possible should be applied to the workpiece, in particular to avoid influencing the vibration, measurement and / or damping.

[0191] A first embodiment of a drive means is outlined in Figs. 19 to 22a. The drive means here comprises a drive roller 52a. The drive roller 52a is pressed or forced onto the workpiece W by the weight of the drive roller or a drive device (not shown) driving the drive roller. The drive roller 52a is preferably equipped with a friction lining, which can preferably generate a defined slip.

[0192] 20 and 21 show a pivoting device for or with the drive roller. The drive means comprises a pivoting device which is designed to selectively press the drive roller 52a onto the workpiece W or to lift it off the workpiece. The pivoting device comprises a pivotable holder 521a for the drive roller 52a, as well as a corresponding drive 522a for pivoting the pivoting device, for example a hydraulic cylinder. In FIGS. 20 and 21, the pivoting movement about the pivot axis is also indicated by the semicircular arrow. The contact pressure or contact force of the drive roller 52a on the workpiece W can be used to set or influence the slip between the workpiece W and the drive roller 52a. If the drive roller 52a is used when measuring the imbalance of the rotor shaft orof the workpiece W is lifted from it, i.e. is no longer in contact, it can secure the workpiece W against being lifted out of the workpiece holder 11, 13. The bracket 7, 71 can then be omitted.

[0193] Figs. 20 and 21 show how a drive roller acts on the center section of a workpiece designed as a rotor shaft. It is also conceivable for the drive roller to act on other parts of the rotor shaft, such as a flange Z or thrust washer D.

[0194] It is further preferably provided that the drive means, in particular the drive roller 52a, is configured to permit a superimposed movement and further drive of the workpiece. This means that the drive roller 52a preferably enables the alternating left and right oscillation of the workpiece holder 13, 23 or the workpiece W. For this to be possible, the drive roller 52a must be able to be pushed back radially by the workpiece W in order to maintain contact to the left and right of the maximum elevation (deflection of the drive roller 52a) of the workpiece W. If this were not possible, the drive roller 52a would influence or prevent the oscillation and thus the measurement.

[0195] Fig. 22 and Fig. 22a show how the workpiece holder swings to the left and right, indicated by the double arrow, while the drive roller 52a is stationary relative to it, as it is fastened, for example, via the holder, to the connection device 11 or to the machine bed 4. The point of contact between the drive roller 52a and the workpiece W moves or alternates, indicated by the double arrow in Fig. 22a. The three indicated representations of the workpiece W with their center point relative to the drive roller 52a are intended to indicate the maximum deflection of the workpiece W to the left AL max or maximum deflection to the right ARmax. In the position AO, the workpiece W or the workpiece holder 13, 23 is not deflected. As shown in Figure 22a, the drive roller 52a alternately comes to rest more to the left or more to the right on the workpiece W. The drive roller 52a can move upwards and thus enables the swinging or alternating movement of the workpiece W.In addition, with W-ALmax the workpiece is shown in its maximum left deflection ALmax and with W-ARmax the workpiece is shown in its maximum right deflection ARmax. For reasons of clarity, in Figure 22 the drive wheel 52a is fixed and the workpiece W "deviates", although the workpiece W in the machine mainly executes the previously described alternating left-right oscillation and the drive roller 52a can execute the evasive or vertical evasive movement. In addition, for the sake of clarity, in other figures the drive roller 52a is shown to the left and right of the workpiece, although the previous movements occur relative to one another.

[0196] During the initial drive or when bringing the workpiece up to speed, the drive roller can exert a lot of force on the workpiece or be pressed against it. During the measuring process, the contact force is usually or preferably reduced. Slippage from the workpiece may occur. Preferably, there is little to no influence on the measurement or the vibration of the fixture.

[0197] The drive roller preferably rests on the workpiece under its weight. Lateral movement of the workpiece is generally possible. It is possible to keep the workpiece at a constant speed. The drive roller can be used to prevent the workpiece from lifting off.

[0198] Reference is made below to Figs. 23 to 25.

[0199] In Fig. 23 to Fig. 25 a further embodiment of a drive means is outlined.

[0200] The drive means here comprises a belt drive 52b.

[0201] The belt drive essentially comprises a drive pulley 521b, two tension pulleys 522b, 523b, and a belt 524b. The belt is shown in dashed lines in the figures. The belt partially wraps around the workpiece. It is preferably provided that the drive means, in particular the belt drive 52b, allows an oscillating movement of the workpiece holder 13, indicated by the double arrow.

[0202] The drive is preferably also achieved by friction with slip. The belt 524b can also comprise a grinding belt, for example. Figure 23 shows the maximum deflection of the workpiece to the left, whereas Figure 24 shows the maximum deflection of the workpiece W or the workpiece holder 13 to the right.

[0203] A particular advantage of the belt drive is that the contact force can be adjusted by adjusting the belt tension. For example, Figure 25 shows a belt drive arrangement with lower belt tension. During initial drive or when bringing the workpiece up to speed, the belt can exert a lot of force on the workpiece, or press it against it.

[0204] During the measuring process or when maintaining the speed, the contact force is preferably reduced, especially the belt tension. This preferably creates slippage relative to the workpiece.

[0205] There is little to no influence on the measurement. Oscillation of the fixture is preferentially achieved, as lateral movement of the workpiece is possible. It is possible to maintain the workpiece at a constant speed, preventing it from lifting off the fixture.

[0206] Fig. 19 shows a schematic illustration of a low or reduced contact pressure by the belt or a raised belt drive.

[0207] As a further alternative or additional drive means 52, it is also conceivable for the machining means 6, in particular in the form of a rotating grinding wheel, to be used to accelerate the workpiece, in particular the rotor shaft. However, the actual unbalance measurement is again carried out without the machining means 6 as the drive means, i.e., a measurement is carried out without contact with the grinding wheel.

[0208] Reference is made below to Fig. 26 to Fig. 28.

[0209] The method according to the invention will be explained in more detail below with reference to Figs. 26 to 28. It is understood that only a few selected method steps are shown here, as they are helpful for understanding the method according to the invention. The method may include further steps or intermediate steps known to those skilled in the art.

[0210] It essentially involves the process of eliminating an angular error during clamping. Ideally, the rotational axis of the workpiece to be balanced is 100% parallel to a theoretical rotational axis, as would result from ideal workpiece holders 13, 23. In practice, however, angular deviations always occur, particularly with regard to the rotational axis of the workpiece to be clamped, which are not directly caused by the workpiece's imbalance, but rather by positioning errors. The following describes a method by which such angular deviations can be eliminated, or at least mitigated, during unbalance measurement.

[0211] In a first process step, a setup workpiece E is produced for an initial balancing measurement. The setup workpiece E is essentially a workpiece that will later be balanced or machined in series production, in particular a rotor shaft.

[0212] A first area Bl is created on the surface of the setup workpiece E, which can be created by removing material or adding material. In the case of removal, a flat spot results, for example. In the case of adding material, a material accumulation results, for example.

[0213] In a next process step, a first unbalance measurement is performed with a setup workpiece E designed in this way. The "artificially" generated unbalance through the area Bl can be identified in the measurement.

[0214] In the next process step, another area B2 is applied to the setup workpiece E. Assuming that the first area is positioned at 0° with respect to the circumference of the workpiece, the second area is positioned, for example, at 90°. However, the aim is to ensure that the areas are arranged at the most precise angle to each other. The removal or accumulation of material in the two areas should also be as identical as possible. However, the additional area B2 is located at the same axial position on the workpiece as the first area.

[0215] In a next process step, a further unbalance measurement is carried out, this time with the setup workpiece with the first area B1 and the second area B2 offset by 90°. Due to the previously known areas B1, B2 with defined angular distances and masses or mass reduction, the resulting unbalance of the setup workpiece becomes visible in the unbalance measurement during its rotation, in particular with regard to the predetermined angular offset, in this case 90°, and the angular offset measured by the further unbalance measurement, which is generally not equal to 90°. From this difference, the angular deviation caused by the unbalance measuring device can be deduced and this can be taken into account when measuring the unbalance with a workpiece to be balanced, i.e. a series workpiece. Specifically, the correction can be incorporated into the control system of the machining device, in particular the unbalance measuring device.be taken into account when calculating the masses to be removed. The machining equipment, especially the unbalance measuring device, is thus calibrated.

[0216] Modifications or extensions of the process may be considered if necessary, in particular performing the steps on the other side of the workpiece, meaning the axially opposite side to the one mentioned above. Areas B1' and B2' are shown here as examples. However, these additional areas B' also lie at the same axial position. It may also be possible to apply the areas simultaneously on both sides of the workpiece, particularly at the same or different angular positions.

[0217] It is also conceivable that the above-mentioned steps are carried out several times, individually or in total, for example in further areas, in particular the third area B3, B4, etc. up to, for example, the 24th area, if the division is, for example, 15°, although other divisions are of course also conceivable.

[0218] Another embodiment of the method is as described below. Regions B are formed which are preferably distributed around the circumference of the setup workpiece E. With a 90° angular offset, this means at least 4 regions B1 to B4. To ensure that the effects on the setup workpiece E are minimal, regions B1' to B4' are created on the other side of the setup workpiece E, preferably in the same angular position, on the surface of the setup workpiece E by removing material. If material is removed, this results, for example, in a flat spot. The flat spots created should have no effect, or as little effect as possible, on the imbalance of the setup workpiece E. The flat spots are therefore formed evenly. However, flat spots are advantageous because in subsequent steps, defined balancing masses or reference masses M are fixed or applied at different angular positions and thus to selected flat spots.To ensure that the flat spots have little influence on the imbalance, they should have the same depth, especially 0.3 mm.

[0219] After at least the areas B1 to B4, preferably also B1' to B4', have been formed, a defined mass is applied to a flat spot or area B in a next process step. If it is assumed that the first area is arranged at 0° with regard to the circumference of the workpiece, then the first mass M1 is applied, for example, at 0°. In a next process step, an unbalance measurement is carried out, now with the setup workpiece E. Subsequently, a further mass M2 can be arranged in the second area B2, for example at 90°. A further unbalance measurement is also carried out with this mass, now with the setup workpiece E.

[0220] Due to the previously known areas B1, B2 with defined angular distances and masses or mass reduction, the resulting unbalance of the setup workpiece becomes visible during its rotation in the unbalance measurement, in particular with regard to the predetermined angular offset, in this case 90°, and the angular offset measured by the further unbalance measurement, which is usually not equal to 90°. From this difference, the angular deviation caused by the unbalance measuring device can be deduced, and this can be taken into account during the unbalance measurement with a workpiece W to be balanced, i.e. a series workpiece. Specifically, the correction can be incorporated into the control system of the machining device, in particular the unbalance measuring device, or taken into account when calculating the masses to be removed. The machining device, in particular the unbalance measuring device, is thus calibrated.

[0221] The previously described measurement of the balancing fixture can also be referred to as calibration. With such a calibrated fixture, highly accurate reference surfaces can be created and more precisely balanced, or material can be removed more precisely during balancing. Calibration is advantageous, for example, when reconstructing the fixture, replacing a tool or clamping device, and so on.

[0222] In a further embodiment of the balancing process described above, the machined workpiece W, i.e. the rotor shaft, is checked or inspected after balancing. During this check, the material removal during balancing is checked. This means that the actual material removal is checked visually and / or tactilely. Here, for example, the shape (edge ​​accuracy) and / or the radial and / or axial position of the material removal can be inspected and evaluated. The material to be removed (weight and position) is stored in the data processing system. By comparing the target and actual values, conclusions can be drawn about the material actually removed (and thus the weight). This can be used, for example, to inspect the device, tool, etc. and to detect wear and incorrect settings.Preferably, 10 shafts, i.e., shafts whose balancing results lie within the desired parameters, are also measured. With knowledge of position or shape errors during mass removal, or of a calculated and incorrectly removed mass or mass difference, the balancing quality of future balanced workpieces W can be improved. This comparison and information are preferably processed in the data processing system and / or with a computer program and used to control the device. The previously described measurement of the workpieces can be carried out according to a test plan, for example, always or based on the number of balanced workpieces.

[0223] Figure 28 shows a balanced workpiece, wherein a flat spot AF and areas AC running concentrically to the bearing point were formed by material removal for balancing by means of grinding wheel 6.

[0224] The spring device 12 shown in the figure, in particular its adjustment, can be protected by a protection S against grinding abrasion and the like.

Claims

Claims 1. Unbalance measuring device (U), comprising - two workpiece holding devices (1, 2) spaced apart from one another for rotatably holding a workpiece (W) whose unbalance is to be measured, and - at least one sensor (3) for detecting a vibration of the workpiece (W) during rotation, wherein - the workpiece receiving devices (1, 2) each have a connecting device (11 or 21) for stationary fastening, as well as a workpiece holder (13 or 23) for rotatingly receiving a workpiece section, wherein - a spring device (12 or 22) is arranged between the connecting devices (11 or 21) and the workpiece holders (13 or 23), characterized in that the spring device comprises a rod segment (121a), as well as a first holder (121b) and a second holder (121c), wherein the rod segment (121a) is clamped at its end into the first holder (121b) and the second holder (121c).

2. Unbalance measuring device (U) according to claim 1, characterized in that the first receptacle (121b) is connected to the connecting device (11) and the second receptacle (121c) is connected to the workpiece holder (13), in particular is fastened by means of screws.

3. Unbalance measuring device (U) according to at least one of the preceding claims, characterized in that the rod segment (121a) is designed as a rod-shaped profile.

4. Unbalance measuring device according to at least one of the preceding claims or according to the preamble of claim 1, characterized in that the unbalance measuring device is equipped with an angular position sensor device (3a), comprising an angular position sensor (33a), for determining the angular position of the workpiece (W) on the workpiece holder (13), wherein the angular position sensor (33a) is connected to the workpiece holder (13).

5. Unbalance measuring device according to claim 4, characterized in that the angular position sensor device (3a) has a bracket (31a), a connection (32a) for a Angular position sensor (33a) and an angular position sensor (33a) received with the connection (32a).

6. Unbalance measuring device according to at least one of claims 4 to 5, characterized in that the bracket (31a) has the shape of a circular segment.

7. Unbalance measuring device according to at least one of claims 4 to 6, characterized in that the bracket (31a) comprises a connection (311a) for pivotable fastening to the workpiece holder (13), as well as an elongated hole (312a) for fastening the connection (32a) for the angular position sensor (33a), wherein the connection (32a) for the angular position sensor (33a) is fastened to the bracket (31a) by means of a screw, wherein the screw is inserted through the elongated hole (312a).

8. Machining device for a workpiece (W), comprising - a machining holder (5) for receiving the workpiece (W), comprising a first holding means (51), a second holding means (53) and a drive means (52), wherein the drive means (52) is designed to set the workpiece (W) in rotation, wherein the holding means (51, 53) are designed to hold the workpiece (W), - at least one processing means (6) for processing the workpiece (W), and - an unbalance measuring device (U) according to at least one of the preceding claims or the preamble of claim 1, characterized in that the drive means comprises a drive roller (52a).

9. Processing device according to claim 8, characterized in that the drive roller (52a) is equipped with a friction lining.

10. Machining device according to at least one of the preceding claims, characterized in that the drive means comprises a pivoting device (521a, 522a) which is designed to selectively press the drive roller (52a) onto the workpiece (W) or to lift it off the workpiece (W).

11. Machining device for a workpiece (W), comprising - a machining holder (5) for receiving the workpiece (W), comprising a first holding means (51), a second holding means (53) and a drive means (52), wherein the Drive means (52) is designed to set the workpiece (W) in rotation, wherein the holding means (51, 53) are designed to hold the workpiece (W), - at least one processing means (6) for processing the workpiece (W), and - an unbalance measuring device (U) according to at least one of the preceding claims, characterized in that the drive means comprises a belt drive (52b).

12. Machining device according to claim 11, characterized in that the belt drive (52b) comprises a drive roller (521b), two tension rollers and a belt.

13. A method for calibrating an unbalance measuring device, in particular an unbalance measuring device according to one of the preceding claims, characterized by the following method steps: - applying a first area (Bl) to a setup workpiece (E); - Carrying out a first unbalance measurement with the setup workpiece (E) on the unbalance measuring device (U) to be calibrated; - applying a second region (B2) to the setup workpiece (E), wherein the second region (B2) is arranged at a predetermined angular offset, in particular 90°, from the first region (B1); - Carrying out a second unbalance measurement with the setup workpiece (E) on the unbalance measuring device (U) to be calibrated and determining a measured angular offset between the first area (B1) and the further area (B2); - Calibrating the unbalance measuring device (U) by taking into account the deviation between the angular distance measured by the second unbalance measurement and the predetermined angular distance.

14. Method according to claim 13, characterized in that the regions (B1, B2) are designed as recesses, in particular flat areas, or accumulations of material.

15. Method according to at least one of the preceding claims, characterized in that more than two regions (B1, B2, B3, B4, ...) are arranged on the setup workpiece (E), which regions are arranged at a predetermined angular offset from one another.

16. Method according to at least one of the preceding claims, characterized in that the regions are arranged at a first axial end of the setup workpiece (E) or further regions are arranged at another axial end of the setup workpiece (E), wherein the regions (B1, B2 or B1', B2') are arranged at one axial end at a common axial position.

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