Disc grinding / polishing machine
By using a synchronous motor and an encoder-free permanent magnet synchronous motor in the disc grinding/polishing machine, the belt transmission is cancelled and the suspension device and lifting mechanism is used to solve the problems of low efficiency and maintenance difficulty in the low speed range, and an efficient and reliable grinding/polishing process is achieved.
Patent Information
- Application Number
- CN202380070424.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-10-05
- Filing Date
- 2023-10-05
- Publication Date
- 2025-05-16
AI Technical Summary
Existing disc grinding/polishing machines have problems with speed fluctuations and high magnetization currents in the low speed range, resulting in low efficiency and excessive heat generation. In addition, the belt transmission device has problems such as increased mass inertia, high slip risk and large structural space occupation, which affects the reliability and maintenance difficulty of the equipment.
The synchronous motor is used as the direct drive device, and the encoder-free permanent magnet synchronous motor (PMSM) is used as the driving of the grinding/polishing disc and sample holder. The belt transmission is cancelled and the suspension device and lifting mechanism are used instead to achieve high-precision contact pressure control.
Significantly reduces bearing load and wear, reduces noise and maintenance requirements, improves equipment reliability and quality of grinding/polishing finished products.
Smart Images
Figure CN120018933A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a disc-shaped grinding / polishing machine, which utilizes a grinding / polishing disc in a receiving groove to plane grind and / or polish the sample surface on the lower side, especially of a mounted and / or unmounted sample. The disc-shaped grinding / polishing machine is particularly used for preparing samples for metallographic analysis. Background Art
[0002] Disc grinders typically have two drives. One drive is located at the bottom and drives the grinding / polishing disc. The other drive is located at the top in the grinding / polishing head and drives the sample holder. The grinding / polishing disc typically rotates at a speed of 50 min. -1 With 500min -1 The power is approximately 0.75 kW to 1.5 kW for a grinding / polishing disc with a diameter of 300 mm, or approximately 2.2 kW for a grinding / polishing disc with a diameter of 350 mm.
[0003] Overall, the known disc grinding / polishing machines have proven to be very successful in practice, but the inventors see potential for further improvements in the context of the situation described below.
[0004] In known disc grinding / polishing machines, the drive is typically realized by a single-phase or three-phase asynchronous motor, which has a power of about 1450 min / min in the case of a four-pole configuration, for example. -1 In order to stably provide the required speed without speed fluctuations, especially in the low speed range, the speed is typically provided by a relatively large reduction ratio (e.g., about 5:
[0005] 1) is transmitted to the grinding / polishing disc via a belt drive.
[0006] For grinding / polishing heads, a lower speed is required. This speed is typically about 20 min. -1 Up to 200min -1 . Like the grinding / polishing disc below, the grinding / polishing head is typically also driven by an asynchronous motor. Therefore, for the grinding / polishing head, the reduction ratio of the belt drive must be selected to be more extreme than for the grinding / polishing disc, and for the grinding / polishing head, the reduction ratio is usually about 8:1 to 10:1. However, due to the limited installation space, this has the disadvantageous consequence that the drive pulley on the motor must be selected to be very small. In addition, this leads to a relatively small wrap angle of the pulley.
[0007] Another disadvantage of these high-speed asynchronous motors is that, in particular in the low speed range, very high magnetizing currents are required in order to achieve high torques, but this is inefficient and generates a lot of heat.
[0008] Another disadvantage of the belt drives used is that the mass inertia of the drive increases with the square of the transmission ratio. In the event of a sudden blockage of the grinding / polishing disc or at the grinding / polishing head, this can lead to slipping of the belt drive, which can accelerate wear or even lead to failures.
[0009] Furthermore, due to the above-mentioned unfavorable wrap angle and the small diameter of the drive pulley, the belt must be designed to be larger in order to be able to transmit the required torque. This in turn causes strong deformation and thus friction, which in turn accelerates the wear of the belt.
[0010] Furthermore, the belt tension recommended by the manufacturer must be adhered to precisely, which should be ensured, for example, by means of frequency measuring devices. If the belt is stretched too tight, this can lead to damage to the bearings on the drive motor. If the belt is stretched too loose, the belt will slip, which in turn can lead to wear and complete failure. In disc grinding / polishing machines, the belt should be re-tensioned regularly, which is usually done by the customer. However, customers usually do not have measuring equipment for checking the belt tension, so that in actual practice it often happens that the belt is stretched too tight. This can lead to overloading of the bearings and can even lead to failure of the drive motor due to bearing damage, which can result in expensive on-site repair costs for the customer.
[0011] In the practical use of grinding / polishing machines, the belt drive is always replaced at certain intervals, which is not without problems on site. On the one hand, the equipment must be partially disassembled, and on the other hand, measuring equipment for accurately determining the belt tension is often not available on site, which in turn leads to the above-mentioned indirect damage.
[0012] Known belt drives also have structural disadvantages. First, a tensioning possibility needs to be provided, which is typically achieved by a transverse displacement of the motor. Here, the belt drive for the motor and the adjustment area for the belt tensioning both require corresponding structural space in the device.
[0013] A further disadvantage is that even if the belt tension is set correctly, permanent transverse forces are generated by the belt tension on the grinding / polishing disc and the drive spindle of the grinding / polishing head.
[0014] In addition, in known disc grinding / polishing machines (whether using a separate pressing method or a center pressing method), the sample is pressed against the rotating grinding / polishing disc with a defined contact pressure (Andruckkraft) to ensure that an appropriate amount of material is removed from the sample to be prepared. The size of the contact pressure varies according to the preparation method, and typically the size of the contact pressure for each sample in the separate pressing method can be between 5N and 100N, and the size of the contact pressure in the center pressing method can be between 20N and 750N. This force is usually generated pneumatically by a defined piston surface. Depending on the type of structure, seals, guides, etc. used in pneumatic systems have friction properties that are not always constant. This friction property may change between static friction and sliding friction, for example, due to temperature changes or due to contamination.
[0015] All of these can affect the accuracy of the abrasive removal, or more generally, the quality of the finished ground and polished product. Summary of the invention
[0016] It is therefore an object of the present invention to provide a disc grinding / polishing machine which ensures high-quality ground and polished finished products.
[0017] Another aspect of the object is to provide a disc-shaped grinding / polishing machine which provides a reliable and high-quality pressing method in the grinding / polishing head and ensures precise control of the grinding removal.
[0018] Another aspect of the object is to provide a disc grinding / polishing machine which avoids the disadvantages of applying grinding forces using pneumatic feed and enables compressed air to be supplied for individual pressing of the sample in the grinding / polishing head in a manner that is highly reproducible and less prone to damage due to temperature fluctuations.
[0019] Another aspect of the object is to provide a disc grinding / polishing machine which makes optimal use of the available construction space, in particular in the grinding / polishing head, and, if necessary, enables a reliable measurement of the contact pressure during grinding and / or polishing and enables a precise setting of the grinding removal amount.
[0020] A further object is to provide a disc grinding / polishing machine which is reliable, low-wear and low-maintenance and which generates little noise during operation.
[0021] The object of the invention is achieved by the subject matter of the independent claim. Advantageous developments of the invention are defined in the dependent claims.
[0022] According to the invention, a disc-shaped grinding / polishing machine is provided for plane grinding and / or polishing of sample surfaces on the underside, in particular mounted and / or unmounted samples, by means of a rotating grinding / polishing disc, in particular for preparing samples for metallographic analysis, for example for subsequent hardness testing or structural testing of the ground and polished underside, in particular of mounted samples.
[0023] The disc-shaped grinding / polishing machine has a grinding / polishing head with a sample holder for inserting one or more mounted or unmounted samples. The sample holder can, for example, include a receiving plate with a plurality of, for example, six, sample containers symmetrically distributed around a rotation axis, which are used to insert mounted or unmounted samples, respectively.
[0024] In metallographic analysis, the mounted sample is ground and polished, for example, after the sample block has been separated with a separator and then mounted in a mounting material, so that the mounted sample is shaped into a more or less standardized shape, for example the shape of a cylinder with a diameter in the range of 25 mm and 50 mm. This is also referred to as metallographic mounting in the art. Disc-shaped grinding / polishing machines are suitable as laboratory equipment, in particular, for such mounted samples. However, the disc-shaped grinding / polishing machines can also work with unmounted samples. For this purpose, the unmounted sample can be directly inserted into a special sample holder that matches the sample.
[0025] The disc-shaped grinding / polishing machine also comprises a lower housing with a receiving tank for receiving a grinding and / or polishing suspension. Water is usually used for cooling during the grinding process, so that a suspension consisting of grinding removal and water can be received in the receiving tank and discharged through a drain outlet of the receiving tank. Polishing is mainly carried out with a polishing suspension, such as a diamond suspension, which is supplied to the polishing disc or the polishing cloth before and / or during the polishing process. The polishing suspension can also be collected in the receiving tank and discharged through the drain outlet.
[0026] The horizontal grinding / polishing disc rotates around a vertical rotation axis in a receiving groove. On the upper side of the grinding / polishing disc, different grinding pads can be selectively fixed in a detachable manner, for example: grinding papers, grinding films, grinding sheets with different particle sizes and different abrasive particles (for example corundum or diamond), so that different grinding pads can be used in sequence to grind the sample more and more finely. Then, the polishing pad and / or polishing cloth can be fixed to the grinding / polishing disc in a detachable manner so that the same sample is first ground and then polished. The grinding pad and the polishing pad or the polishing cloth can be adhered to the upper side of the grinding / polishing disc, for example, magnetically, self-adhesively, vacuum-adsorbed, and using optional other adhesive layers. Therefore, the lower side of the sample pressed onto the grinding / polishing disc from above is flatly ground and / or polished by the corresponding grinding pad, polishing pad or polishing cloth.
[0027] Preferably, mounted or unmounted metallographic samples can be first ground (if necessary with different abrasive grains) using the same disc grinder and polisher and then directly polished (if necessary with polishing suspensions of different finenesses) without having to remove the sample from a correspondingly matched sample holder. A cleaning station can also be provided if necessary.
[0028] The disc grinder / polisher includes an upper first drive motor disposed in the grinder / polisher head for rotationally driving the sample holder.
[0029] The disc-shaped grinding / polishing machine further includes a lower second driving motor disposed in the lower housing for rotationally driving the grinding / polishing disc.
[0030] The sample holder is driven by a first drive spindle, and the first drive motor has a first stator and a first rotor. The first drive spindle is coaxially connected to the first rotor, in particular in a form-fitting or friction-fitting manner, and in particular extends coaxially through the first rotor and the first stator, so that the first drive motor and the first drive spindle form a coaxial first direct drive for the sample holder. The sample holder is particularly coaxially, preferably detachably, fixed to the lower end of the first drive spindle.
[0031] Alternatively or additionally, the grinding / polishing disc is driven by a second drive spindle, and the second drive motor has a second stator and a second rotor. The second drive spindle is coaxially connected to the second rotor, in particular in a form-fitting or friction-fitting manner, and in particular extends coaxially through the second rotor and the second stator, so that the second drive motor and the second drive spindle form a coaxial second direct drive for the grinding / polishing disc. The grinding / polishing disc is in particular coaxially, preferably detachably, fastened to the upper end of the second drive spindle.
[0032] Thereby, the disc-type grinding / polishing machine can have a respective coaxial direct drive for the sample holder, or for the grinding / polishing disc, or preferably for both, as defined above.
[0033] The speed of the first drive motor is preferably within 20min -1 and 200min -1 The speed of the second drive motor is preferably within the range of 50 min -1 and 600min -1 In particular, the rotation speed may be adjustable.
[0034] According to a preferred embodiment, the first and / or second drive motor is configured as a synchronous motor, in particular as a multi-pole or multi-pole torque motor. Preferably, the drive motor is configured in the form of an inner rotor.
[0035] Therefore, instead of a conventional asynchronous motor with a belt drive, a torque motor is used as a direct drive, for example. The torque motor can be designed as an encoderless synchronous motor with permanent magnets in the rotor (permanent magnet synchronous motor - PMSM). The corresponding stator can consist of a plurality of coils, which generate a magnetic field by corresponding current supply, and the associated rotor follows this magnetic field. The torque motor can accelerate from a standstill to the maximum speed required here (approximately 200 min / min). -1 or 600min -1 ) and are used as direct drives, i.e. without belt drives or other transmissions. The corresponding rotor can be directly coaxially mounted on the drive spindle of the grinding / polishing disc or the drive spindle of the grinding / polishing head and thus transmits only the drive torque. The connection between the corresponding rotor and the associated drive spindle can be achieved, for example, by a form fit, for example using a feather key, or by a friction fit. The transverse forces applied to the spindle by the belt in conventional disc-shaped grinding / polishing machines are eliminated, which significantly reduces the bearing load and thus significantly reduces wear. In addition, the drive device is almost silent and does not require maintenance at all, thereby eliminating on-site maintenance work on the customer's side. The drive unit can be constructed compactly as a whole, whereby the drive unit has a slender design despite the high torque.
[0036] Preferably, the disc-shaped grinding / polishing machine has a motor-driven vertical lifting mechanism, by means of which the grinding / polishing head (together with the first drive motor) is lowered onto the grinding / polishing disc for plane grinding and / or polishing of the sample. Thus, in an advantageous manner, the desired amount of material can be removed with high precision.
[0037] Preferably, the lifting mechanism has at least one, preferably at least two vertical guides, a lead screw (e.g. a ball screw), and a lead screw drive motor. Preferably, the lead screw drive motor rotates the lead screw and the lead screw nut or the circulating guide (e.g. a ball guide of a ball screw) relative to each other so as to make the grinding / polishing head perform a vertical lifting movement along the vertical guide. As a result, the grinding / polishing head moves up and down, and thus the sample in the sample holder can be accurately fed during the grinding and / or polishing process.
[0038] The spindle drive motor can be designed, for example, as a stepper motor with a rotary encoder.
[0039] According to a preferred embodiment, the grinding / polishing head is suspended on an L-shaped suspension device, which has a vertical tower and a horizontal bridge. The vertical tower can be fixed on the device support foot in the lower shell and extends vertically upward from the device support foot (especially on the rear side of the lower shell). The horizontal bridge is in turn suspended on the vertical tower and extends horizontally above the lower shell to the grinding / polishing head, or to the area above the grinding / polishing disk. The grinding / polishing head is suspended at the front end of the bridge opposite to the tower, so that the suspension device and the grinding / polishing head basically construct a U shape. Preferably, a vertical lifting mechanism is arranged in the vertical tower and raises and lowers the horizontal bridge together with the grinding / polishing head and the coaxial first direct drive device. Preferably, the first drive spindle is suspended on the rigid area of the grinding / polishing head in an axial elastic rebound manner.
[0040] The first drive spindle can be supported above and below the first rotor, in particular by means of rolling bearings, preferably ball bearings. The lower bearing of the first drive spindle can be designed as a fixed bearing, in particular having at least one angular contact ball bearing or deep groove ball bearing, and preloaded by a wave spring in order to eliminate bearing play.
[0041] Furthermore, the upper bearing of the first drive spindle can be designed as a floating bearing, in particular with a cylindrical roller bearing, in order to absorb axial movements of the first drive spindle together with the first rotor relative to the first stator and the suspension of the grinding / polishing head.
[0042] The second drive spindle is preferably also mounted above and below the second rotor, in particular by means of angular contact ball bearings or deep groove ball bearings.
[0043] For surface grinding and / or polishing with the center-press method, the sample is in particular fixedly clamped in a sample holder. By feeding the entire grinding / polishing head together with the first drive motor, a defined contact pressure F A The central pressure is applied to the sample holder via the first drive spindle.
[0044] In other words, using a motorized lift mechanism for the grinding / polishing head, center pressing can be achieved through the sample holder, which enables precise control of grinding removal.
[0045] Preferably, in particular in the case of a grinding / polishing head, a contact pressure acting on the first drive spindle of the direct drive relative to the grinding / polishing head is measured by means of a force measuring device. Furthermore, the force measuring device can be used to determine the contact zero point of the sample with the grinding / polishing disk when the grinding / polishing head is lowered onto the grinding / polishing disk. The contact pressure causes an elastically resilient axial movement of the first drive spindle relative to the rigid region of the suspension device, in particular corresponding to which the force measuring device measures the contact pressure F in particular between the first drive spindle and the rigid region of the suspension device of the grinding / polishing head. A .
[0046] In the case of the central pressing method, the force is preferably applied to the sample not by means of a pneumatic piston, but electrically (for example, using a spindle drive). In this case, the force can be measured by means of a force measuring device, and the drive motor for the lifting mechanism can be regulated in a closed loop via this signal, which in turn can apply a precise feed movement with the correct load, for example, via a ball screw. Similarly, the motor position can be calculated using the electric spindle drive of the lifting mechanism, for example, using a rotary encoder, so that the exact path length is output. In this way, a precisely defined sample removal amount can also be achieved at a precisely defined feed force.
[0047] The grinding / polishing machine also preferably has a device for determining the zero point, by means of which the contact of the lower surface of the sample with the grinding / polishing disc or the grinding pad can be detected. Thus, the exact zero point can be determined, i.e. the surface of the sample from which the material removal is measured. To determine the zero point, the collision of the sample on the grinding / polishing disc is detected when the grinding / polishing head is lowered. Thus, the material removal of the sample during the grinding process can be determined precisely in an advantageous manner. If necessary, this can be determined or set in the range of one hundredth of a millimeter to a few thousandths of a millimeter, which is conducive to penetration into a specific layer of the sample.
[0048] In particular, the material removal amount can be precisely set with an electric lift, since this allows a rigid feed drive to be implemented which, in contrast to pneumatic force applications, avoids unknown friction forces in the system and inaccuracies caused, for example, by the compressibility of air. The determination of the zero point therefore has a particularly synergistic effect in combination with an electric lift.
[0049] For determining the zero point, ie detecting the contact with the sample surface, a force measuring device can be used, as described above, in particular, since it sends a measurable signal at the slightest contact of the sample with the grinding / polishing disk.
[0050] The force measuring device may include one or more force sensors, such as strain gauges, which change their resistance when stretched. At least one force sensor or strain gauge may be mounted on a spring element, such as a leaf spring element, of the force measuring device. The leaf spring element may be arranged around the first drive spindle, preferably below the first drive motor.
[0051] The force measuring device can be annular in shape and preferably extends coaxially around the first drive spindle of the first linear drive. The force measuring device can include a force distribution ring, which extends coaxially around the first drive spindle. In the case of the central pressing mode, the reaction force F generated by the sample holder acting upward on the first drive spindle G , for example, can be unloaded via the lower bearing of the first drive spindle (for example two ball bearings) onto a force distribution ring. The force distribution ring is axially elastically resiliently connected to the suspension of the grinding / polishing head, for example, by means of, in particular, radial leaf spring elements, on which at least one or more force sensors, in particular strain gauges, can be mounted, so that in the case of a central pressing mode, the contact pressure F is measured by means of the strain gauges by means of the stretching of the strain gauges caused by the axial movement of the first drive spindle relative to the suspension. A .
[0052] Therefore, preferably, the motor shaft of the first drive motor, i.e. the first drive spindle, is axially elastically resiliently suspended on the suspension device of the grinding / polishing head together with the first rotor. Here, preferably, the motor shaft of the first drive motor or the first drive spindle is axially elastically suspended on the rigid component of the grinding / polishing head by means of a force measuring device. The force measuring device is preferably roughly roughly configured as an annular shape, and constitutes a force measuring flange, which can be arranged annularly around the motor shaft of the first drive motor or the first drive spindle. Here, the motor shaft of the first drive motor or the first drive spindle coaxially extends through the central opening of the force measuring flange. Therefore, the force measuring device or the force measuring flange is preferably arranged coaxially with the first drive motor. Further preferably, the force measuring device and / or the force measuring flange are arranged to be coaxially with the first rotor of the first drive motor and coaxially with the sample holder at the same time. The first motor shaft or the first drive spindle preferably coaxially extends through the force measuring device or through the force measuring flange.
[0053] According to a preferred embodiment, the first rotor is suspended axially displaceably and coaxially resiliently relative to the first stator. (Central) pressing causes the first rotor to move coaxially relative to the first rotor against the spring force of the resilient suspension device, and the force measuring device measures the force applied to the resilient suspension device by the coaxial movement of the first rotor relative to the first stator.
[0054] In particular, the first drive spindle and the first rotor form the motor shaft of the first drive motor. The first motor shaft with the first drive spindle and the first rotor is in particular suspended resiliently on the grinding / polishing head. The force measuring device can measure the contact pressure directly on the first motor shaft, in particular the first motor shaft coaxial to the first drive spindle and coaxial to the first rotor or coaxial to the first drive motor. When the sample holder with the inserted sample is pressed onto the grinding / polishing disc, in particular in the case of the center pressing method, the first motor shaft is elastically displaced axially relative to the first stator or relative to the rigid component of the grinding / polishing head, overcoming the spring stress of the resilient suspension device of the first motor shaft, and the force measuring device measures the force of the first motor shaft acting on the resilient suspension device of the first motor shaft.
[0055] The elastically resilient suspension or the force-measuring device of the first motor shaft is preferably arranged axially between the first drive motor and the first drive spindle or the lower bearing of the first motor shaft.
[0056] In order to obtain an undistorted signal from the force measuring device, it is extremely advantageous not to introduce transverse forces, for example from a drive belt, into the force measuring device. This can be achieved in particular with a coaxial first direct drive, for example a torque motor, which only introduces a drive torque into the shaft but does not influence the force measuring device. Axial direct drives therefore have a particular synergistic effect, in particular in combination with coaxial force measuring devices.
[0057] The rotor and the stator of the first direct drive motor are preferably axially displaceable relative to each other in order to absorb the axial elastic movement of the first drive spindle when the sample is pressed against the grinding and polishing disc, especially in the case of a central pressing mode. The rotary support of the first drive spindle can also absorb the axial elastic movement when the sample is pressed against the grinding and polishing disc, for example, by means of a cylindrical roller bearing.
[0058] Preferably, the user can input the contact pressure setpoint value into a control device, which controls the lifting mechanism, in particular a lead screw drive motor or a stepper motor, and defines a closed control loop. Then, during the grinding and / or polishing process, the control device automatically and actively regulates the contact pressure applied by the lifting mechanism to the sample holder and to the grinding / polishing disc to the set contact pressure setpoint value in response to the contact pressure measurement value measured by the force measuring device using the control loop.
[0059] Preferably, the sample holder is configured as a multi-purpose sample holder with a plurality of sample containers, which are arranged symmetrically around the rotation axis of the first drive spindle. If necessary, in addition to the motor-driven feed in the central pressing mode, the grinding / polishing head can have a plurality of individual pressing pistons, which individually load the samples respectively placed in the associated sample containers with force.
[0060] The sample holder is designed, for example, to accommodate six samples, which are arranged symmetrically around the rotation axis of the first drive motor or the first drive spindle, so that a plurality of samples can be surface ground and / or polished simultaneously. For the individual pressing method, the samples are placed in the sample container from above. In the case of the central pressing method, the samples in the sample container are additionally fixed and clamped, so that the desired contact pressure for surface grinding and / or polishing is applied centrally to all clamped samples via the first drive spindle and the sample holder.
[0061] These individual pressing pistons can be operated pneumatically. For this purpose, compressed air can be introduced into the first drive spindle through a compressed air interface that is rotatable, in particular, relative to the first drive spindle. The compressed air interface is preferably arranged on the upper end of the first drive spindle, or on the first drive motor. In the first drive spindle, for example, an axial compressed air channel extends, which allows the compressed air to be axially passed through the first rotor and the first stator and directed to an air distributor that rotates with the first drive spindle below the first drive motor. The air distributor can ultimately distribute the compressed air radially to the individual pressing pistons through the distribution channels so as to pneumatically operate these individual pressing pistons. The air pressure can be set by a pressure regulating valve so that the required contact pressure is applied to the grinding / polishing disc.
[0062] The present invention also relates to a disc-shaped grinding / polishing machine, which uses a horizontally rotating grinding / polishing disc to plane grind and / or polish the sample surface on the lower side of a sample, especially a mounted and / or unmounted sample, which is especially used for preparing samples, for example, as a sub-step of preparing samples for metallographic analysis, and the disc-shaped grinding / polishing machine especially has the other features as described above. The disc-shaped grinding / polishing machine according to this aspect comprises:
[0063] a lower housing having a receiving groove for receiving a grinding and / or polishing suspension,
[0064] a horizontal grinding / polishing disc, which is arranged in a receiving groove and rotates about a vertical rotation axis, wherein different grinding pads, such as grinding papers, grinding films, grinding sheets, polishing pads and / or polishing cloths with different grits (e.g. corundum, diamond, etc.) can be selectively adhered to the upper side of the grinding / polishing disc, so that the lower side of the sample pressed from above onto the grinding / polishing disc can be plane ground and / or polished by means of the respective grinding pads, polishing pads or polishing cloths, wherein during operation, a grinding and / or polishing suspension can be received in the receiving groove and discharged through a suspension discharge port of the receiving groove,
[0065] a grinding / polishing head having a sample holder for inserting one or more samples,
[0066] a first drive spindle extending vertically in the grinding / polishing head, wherein the sample holder is coaxially connected to the lower end of the first drive spindle so that the sample holder can be driven in a centrally rotating manner by means of the first drive spindle,
[0067] a first drive motor arranged in the grinding / polishing head, which is used to drive the first drive spindle to rotate, if necessary, to drive the first drive spindle to rotate at a variable speed,
[0068] ·Wherein, the first drive motor comprises a first stator and a first rotor, wherein a first drive spindle is coaxially connected to the first rotor, for example, in a form-fitting or friction-fitting manner, and extends coaxially in the first rotor and the first stator, so that the first drive motor and the first drive spindle constitute a coaxial first direct drive device for the sample holder.
[0069] Preferably, if the grinding / polishing disk is also to be rotated relative to the sample holder at the same time, a second drive motor for the grinding / polishing disk is arranged in the lower housing. The rotation can be in the same direction or in opposite directions.
[0070] Preferably, the second drive motor also constitutes a direct drive device for the grinding / polishing disc. To this end, it also includes a second drive spindle, which extends vertically from the lower housing through the bottom opening of the receiving groove into the receiving groove, and the grinding / polishing disc is connected to the upper end of the second drive spindle, so that the grinding / polishing disc is rotationally driven by the second drive spindle. The second drive motor includes a second stator and a second rotor, wherein the second drive spindle is coaxially connected to the second rotor, for example, in a form-fitting or friction-fitting manner, and extends coaxially in the second rotor and the second stator, so that the second drive motor and the second drive spindle constitute a coaxial second direct drive device for the grinding / polishing disc.
[0071] There are also simple disc-shaped grinding / polishing machines without a grinding / polishing head and an automatic pressing mechanism, in which the sample is ground and polished manually. It is also conceivable to use the described drive device for the grinding / polishing disc in this simple disc-shaped grinding / polishing machine. Therefore, the present invention also relates to a disc-shaped grinding / polishing machine, which uses a horizontally rotating grinding / polishing disc to plane grind and / or polish the sample surface on the lower side of a sample, in particular a mounted or unmounted sample, in particular as a sub-step of preparing a sample for metallographic analysis, and the disc-shaped grinding / polishing machine in particular has the other features as described above. The disc-shaped grinding / polishing machine comprises:
[0072] a lower housing having a receiving groove for receiving a grinding and / or polishing suspension,
[0073] a horizontal grinding / polishing disc, which is arranged in a receiving groove and rotates about a vertical axis of rotation, wherein different grinding pads, such as grinding papers with different grits (e.g. corundum, diamond, etc.), grinding films, grinding sheets, polishing pads and / or polishing cloths, can be selectively adhered to the upper side of the grinding / polishing disc, so that the lower side of a sample pressed from above onto the grinding / polishing disc can be plane ground and / or polished by means of the respective grinding pads, polishing pads or polishing cloths, wherein during operation, a grinding and / or polishing suspension can be received in the receiving groove and discharged through a suspension discharge port,
[0074] a second drive spindle extending vertically from the lower housing through a bottom opening in the receiving slot into the receiving slot, wherein the grinding / polishing disc is connected at an upper end of the second drive spindle in the receiving slot so as to be rotationally driven from below by the second drive spindle,
[0075] a second drive motor arranged in the lower housing, which is used to drive the second drive spindle to rotate, and if necessary, to drive the second drive spindle to rotate at a variable speed,
[0076] ·Wherein, the second drive motor comprises a second stator and a second rotor, wherein the second drive spindle is coaxially connected to the second rotor, for example, in a form-fitting or friction-fitting manner, and extends coaxially in the second rotor and the second stator, so that the second drive motor and the second drive spindle form a coaxial second direct drive device for the grinding / polishing disc. BRIEF DESCRIPTION OF THE DRAWINGS
[0077] The invention will be explained in more detail below using exemplary embodiments and with reference to the drawings, wherein identical and similar elements are partially provided with identical reference symbols and features of different exemplary embodiments may be combined with one another.
[0078] It shows:
[0079] · Figure 1 A three-dimensional view of a disc-shaped grinding / polishing machine according to an embodiment of the present invention is shown, wherein the grinding / polishing head is cut away,
[0080] · Figure 2 Shown is a cutaway Figure 1 A vertical cross-sectional view of the grinding / polishing head of a disc-shaped grinding / polishing machine,
[0081] · Figure 3 shows a three-dimensional view of a force measuring device according to an embodiment of the present invention,
[0082] · Figure 4 Shows Figure 3 A top view of the force measuring device.
[0083] · Figure 5Shown along Figure 4 A cross-sectional view of the force measuring device cut through line AA in FIG.
[0084] · Figure 6 An exploded view showing the grinding / polishing head and suspension assembly,
[0085] · Figure 7 A vertical cross-sectional view showing a lifting mechanism for a grinding / polishing head is shown,
[0086] · Figure 8 Shows Figure 1 A partial front cross-sectional view of a disc grinding / polishing machine.
[0087] · Fig. 9 Shown is a cutaway Figure 1 A vertical cross-sectional view of a grinding / polishing disc of a grinding / polishing machine having a receiving groove and a driving device,
[0088] · Fig.10 An exploded view of a grinding / polishing disc with a receiving slot and a drive arrangement is shown. DETAILED DESCRIPTION
[0089] Reference Figure 1 , the disc-shaped grinding / polishing machine 10 has a base housing 12 with a display and / or input device 14, which in this example is in the form of a touch display, by means of which the user can input the desired operating parameters (e.g. rotation speed of the sample holder, rotation speed of the grinding / polishing disc, contact pressure, grinding removal, etc.) into a control device (not shown). A receiving groove 16 for the grinding and polishing suspension is embedded on the top side 12a of the lower housing 12. A grinding / polishing disc 18 is arranged in the receiving groove 16 and rotates about a vertical rotation axis 20 ( Fig. 9 ). The user can selectively attach different grinding pads, polishing pads or polishing cloths to the upper side 18a of the grinding / polishing disc 18. The grinding pad can be configured, for example, as a silicon carbide or diamond grinding disc, grinding paper or grinding film. If necessary, a magnetized film can also be used as an adhesive carrier. For polishing, a polishing pad or polishing cloth can be attached to the upper side 18a, which is used for polishing in combination with a polishing suspension, such as a diamond suspension. Water can be supplied to the grinding pad or polishing pad or the polishing cloth, for example, for wet grinding or rinsing, through the water nozzle 22.
[0090] The grinding / polishing head 30 is suspended on a suspension device 32 above the grinding / polishing disc 18. At the lower end of the grinding / polishing head 30, a central sample holder 34 (in this example, a six-purpose sample holder) is fixed to the drive spindle 66 of the grinding / polishing head 30, wherein the sample holder 34 is rotated around the rotation axis 21 ( Figure 2) is driven rotationally. The sample holder 34 is designed, for example, for mounting samples. The samples to be ground and polished, in particular mounted metallographic samples (not shown), are inserted individually from above into the sample containers 36 of the sample holder 34. For grinding and / or polishing by means of the individual pressing method, a pneumatically operated individual pressing piston 38 is arranged above each sample container 36, by means of which the samples placed in the sample holder 34 can be individually loaded with force from above by means of individual pressing. For grinding and / or polishing by means of the central pressing method, the sample is clamped in the associated sample container 36 and the entire sample holder 34 is loaded with an axial force via the upper drive spindle 66 of the rotary drive in the grinding / polishing head 30, so that the sample is pressed with a defined contact pressure F A Pressing onto the grinding / polishing disk 18 or feeding the grinding / polishing head 30 axially forwards is performed, in particular in order to remove a defined amount of material during the grinding process.
[0091] The suspension device 32 for the grinding / polishing head 30 comprises a vertical tower 42 with a lifting mechanism 44, by means of which a horizontal bridge 46 (on the front end of which the grinding / polishing head 30 is suspended) is raised and lowered. For grinding or polishing with the center-pressing method, the bridge 46 suspended on the lifting mechanism 44 is moved downward by means of the lifting mechanism 44 in order to generate a contact pressure for the grinding or polishing process. The lifting mechanism 44 thus moves the entire grinding / polishing head 30 together with the suspension device 32 to a specific height. For this purpose, in the present embodiment, the lifting mechanism 44 has a stepper motor 48 with a rotary encoder, which generates a vertical stroke by rotating a ball screw 50. The suspension device 32 or the bridge 46 is guided here by two vertical linear guides 52a, 52b, which are subjected to bending moments. The lifting mechanism 44 is arranged in the rear vertical tower portion 42 so that the tower portion 42, the horizontal bridge portion 46 and the grinding / polishing head 30 which may be accommodated in the head housing 47 form a U-shaped arm.
[0092] Reference Figure 2-Figure 6, the upper stator 64 and the upper rotor 62 constitute an upper direct drive motor for the sample container 36, which in this example is in the form of an upper synchronous or torque motor 60. Therefore, the rotational drive of the sample holder 34 is achieved by means of the upper synchronous or torque motor 60 in the grinding / polishing head 30. The upper torque motor 60 is multipolar and is configured in the form of an inner rotor, so that the upper rotor 62 rotates in the upper stator 64. The upper rotor 62 is hollow and coaxially accommodates an upper drive spindle 66, which is connected to the upper rotor 62 in a form-fitting or friction-fitting manner, in this example, in a form-fitting manner by means of a sliding key 68. Therefore, the upper torque motor 60 and the upper drive spindle 66 coaxially connected to the upper rotor 62 constitute a coaxial upper direct drive device 61, which is used for the sample holder 34 coaxially connected to the upper drive spindle 66 at the lower end.
[0093] The upper drive spindle 66 is supported below and above the rotor 62, wherein the lower bearing 70 is configured as a fixed bearing and can include a radial thrust ball bearing or a common deep groove ball bearing. In the present case, the lower fixed bearing 70 consists of two deep groove ball bearings 70a, 70b. The lower bearing 70 is arranged in a bearing housing 71 and is preloaded by a wave spring 72. This preload is used to eliminate bearing play. The two ball bearings 70a, 70b are spaced apart by an intermediate washer 74 and are clamped inside by means of a clamping nut 76.
[0094] A force measuring device 80 is arranged on the upper drive spindle 66, which is designed in the form of an annular force measuring flange 81 in this example and extends around the upper drive spindle 66. The annular force measuring device 80 has an inner force distribution ring 82, when the contact pressure F A The reaction force F GThe force distribution ring is loaded by the upper drive spindle 66 (in the present embodiment via the lower bearing 70) when the sample holder 34 acts axially on the upper drive spindle 66. The force measuring device 80 comprises a leaf spring portion 84, which radially connects the inner force distribution ring 82 with the outer unloading ring 86. For example, the leaf spring portion 84 may comprise four radially extending leaf springs 85, which connect the inner force distribution ring 82 with the concentric outer unloading ring 86 in an axially elastic manner. The individual leaf springs 85 can be distributed particularly uniformly around the coaxial upper drive spindle 66 of the upper direct drive 61. The outer unloading ring 86 is supported, for example, on a rigid region of the grinding / polishing head 30. The force sensor 87 is mounted (for example, a strain gauge 88 is adhered) on the leaf spring part 84, in the present embodiment, on one of the leaf springs 85, which strain gauge 88 changes its ohmic resistance when stretched, so that the stretching of the relevant leaf spring 85 or leaf spring part 84 can be measured when the upper drive spindle 66 is axially displaced relative to the rigid component of the grinding / polishing head 30 or when the spring stress is overcome. The strain gauge can also be mounted or adhered on a plurality of leaf springs 85, for example two or all (here four) leaf springs, which can further improve the force measurement accuracy. The measurement signal of one or more strain gauges 88 can be amplified by a measuring amplifier 89 and transmitted to the control device of the disc grinding / polishing machine 10, in particular in order to regulate the contact pressure F A The measuring amplifier 89 can be mounted directly on the force measuring device 80. For example, the measuring amplifier 89 is embedded in the recess 101 in the force measuring flange 81 and can be cast therein if necessary. In other words, the force measuring flange 81 or the inner force distribution ring 82, the leaf spring part 84 and the outer concentric force relief ring 86 form an axially elastic suspension device for the upper motor shaft of the upper synchronous or torque motor 60, which is composed of the upper drive spindle 66 and the upper rotor 62.
[0095] Therefore, in the case of the center press method, the grinding / polishing head 30 is moved axially downward by the lifting mechanism 44 until the sample clamped in the sample holder 34 contacts the grinding / polishing disk 18. In the case of further vertical feeding with the center press, the sample is moved downward with the contact pressure F A is pressed against the grinding / polishing disc 18, whereby the corresponding reaction force F G The reaction force F acts axially or vertically upward on the upper drive spindle 66. G The deformation of the leaf spring 85 and the extension of the strain gauge 88 are caused, thereby the contact pressure F A Take measurements.
[0096] Instead of the central pressing method, the samples can also be pressed individually by means of the individual pressing piston 38. The individual pressing piston 38 is operated pneumatically and moves downward toward the upper side of the corresponding sample (not shown) against the preload force of the return spring 39. In order to pneumatically operate the individual pressing piston 38, compressed air can be introduced into the upper drive spindle 66 in the center through the compressed air interface 90. The compressed air interface 90 can be rotated relative to the upper drive spindle 66 and guides the compressed air downward through the axial compressed air channel 92, which extends through the upper drive spindle 66 as a central axial hole. At the lower end of the upper drive spindle 66, an intermediate piece 94 with a radial air distributor 96 is fastened. The air distributor 96 guides the compressed air further to the individual pressing piston 38 through the axial connecting channel 98 and the corresponding radial distribution channel 102, so as to operate the individual pressing piston 38 and press it against the inserted sample. Compressed air is thus conducted via compressed air connection 90 through upper drive spindle 66 to air distributor 96 and distributed via radial air distribution channels 102 to, for example, six individual pressing pistons 38 .
[0097] During operation, the upper drive spindle 66 fixedly connected to the upper rotor 62 rotates with the air distributor 96 and the separate pressing piston 38 and the sample holder 34 fixed to the lower end of the upper drive spindle 66. The sample holder 34 can be fastened to the lower part of the upper drive spindle 66 with a quick-release part 104, for example.
[0098] In the case of the center press method, the sample is fixedly clamped in the sample holder 34, and the contact pressure F is set by feeding the entire grinding / polishing head 30. A The contact pressure F is applied to the sample holder 34 via the upper drive spindle 66, wherein the contact pressure F is measured by the force measuring device 80 during the grinding and / or polishing process. A The measurement result of the force measuring device 80 (in the present example in the form of a change in the resistance of the strain gauge 88) is transmitted to the control device of the grinding / polishing machine 10, wherein the control device actively regulates the contact pressure F in a closed control loop in response to the measurement signal. A In other words, the contact pressure F is measured by the force measuring device 80 or the force sensor 87. A and fed back to the control device, whereby it is regulated in a closed control loop (closed loop) to a contact pressure setpoint value which can be input via the input device 14.
[0099] The upper bearing 106 of the upper drive spindle 66 is a floating bearing and is designed in the present example as a cylindrical roller bearing in order to compensate for axial deformations of the force measuring device 80 during the center-pressing method by its axial free mobility. A sealing washer 108 seals the upper drive spindle 66 or the upper rotor 62 relative to a non-rotating cover plate 110.
[0100] Reference Figure 7 and Figure 8 The tower 42 is, for example, suspended on the rear side of a device foot 112 constituting the base of the device in the lower housing 12. Two vertical guide rods 53a, 53b are suspended on the device foot 112 as part of the linear guide device 52a, 52b. The bridge 46 (on whose front end the grinding / polishing head 30 is rigidly fixed) has guide sleeves 54a, 54b at its end opposite to the grinding / polishing head 30, which slide vertically on the guide rods 52a, 52b. The vertical lifting drive of the lifting mechanism 44 is driven by a stepper motor 48. The vertical lifting drive can be configured as a spindle drive 49. More specifically, the stepper motor 48 drives the ball screw 50 through the clutch 116, and the ball screw 50 rotates in the screw nut or the ball guide device 118 to achieve the vertical movement of the suspension device 32, thereby causing the vertical movement of the grinding / polishing head 30. In order to precisely control the vertical lifting movement of the grinding / polishing head 30 , the stepper motor 48 may have a rotary encoder (not shown).
[0101] In addition, the tower 42 can be suspended at the device foot 112 in a horizontally movable manner. For this purpose, the tower 42, in particular together with the lifting mechanism 44, is connected to the device foot 112 in a linearly horizontally movable manner using horizontal linear guides 252a, 252b. In this example, the tower 42 is suspended on guide sleeves 254a, 254b, which slide horizontally on guide rods 253a, 253b. Thus, the tower 42 together with the lifting mechanism 44 can move horizontally parallel to the grinding / polishing sheet 18. The drive of the horizontal movement mechanism 244 can be achieved by a spindle drive 249, for example, using a ball screw 250 with a motor 248. For example, the horizontal movement is performed transversely to the horizontal bridge 46. Thus, when grinding a sample on the grinding / polishing disc 18, a horizontal rocking motion of the sample can be generated, for example. This has the advantage that the wear of the grinding or polishing sheet is evenly performed.
[0102] Generally speaking, the disc grinding / polishing machine 10 includes a horizontal movement mechanism for the grinding / polishing head 30, by means of which the grinding / polishing head 30, together with the first drive motor 60 and / or the force measuring device 80 and the lifting mechanism 44, can be moved motorized transversely to the grinding / polishing disc 18.
[0103] Reference Fig. 9 and Fig.10 , the lower stator 164 and the lower rotor 162 form a lower direct drive motor for the grinding / polishing disc 18, which in the present example has the form of a lower synchronous or torque motor 160. The rotational drive of the grinding / polishing disc 18 is therefore carried out by means of the lower synchronous or torque motor 160. The lower torque motor 160 is constructed in the form of an inner rotor, so that the lower rotor 162 rotates in the lower stator 164. The lower rotor 162 is hollow and coaxially accommodates a lower drive spindle 166, which is connected to the lower rotor 162 in a form-fitting or friction-fitting manner, in the present example in a form-fitting manner by means of a sliding key 168. Therefore, the lower torque motor 160 together with the lower drive spindle 166 coaxially connected to the lower rotor 162 forms a coaxial lower direct drive device 161, which is used for the grinding / polishing disc 18 coaxially connected to the lower drive spindle 166 at the upper end.
[0104] The grinding / polishing disc 18 is located on top of the coaxial lower direct drive 161 so as to be rotationally driven about the lower rotation axis 20 by the lower drive spindle 166. The lower drive spindle 166 extends axially through the lower rotor 162. Thus, the lower rotor 162 and the lower drive spindle 166 are driven by the lower stator 164. Thus, the lower torque motor 160 together with the lower drive spindle 166 constitute a coaxial lower direct drive 161 for the grinding / polishing disc 18 coaxially connected to the lower drive spindle 166.
[0105] The grinding / polishing disk 18 rotates to receive the grinding or polishing suspension in the receiving tank 16. The grinding / polishing disk 18 can be sealed relative to the receiving tank 16 by means of a sealing gasket 169 (eg, a lip seal) to keep the grinding and polishing suspension away from the drive device 161.
[0106] Lower drive spindle 166 is supported axially above and below lower torque motor 160 by means of lower bearing 170 and upper bearing 172. Bearings 170, 172 may be designed, for example, as deep groove ball bearings or angular contact ball bearings.
[0107] Furthermore, the grinding / polishing disk 18 is located on a disk receptacle 19 which is screwed coaxially from above onto the lower drive spindle 166 and which allows for easy removal of the grinding / polishing disk 18. The grinding / polishing disk 18 can be held on the disk receptacle 19, for example, magnetically and in a form-fitting manner.
[0108] An annular splash guard (not shown) may also be optionally mounted on the upper edge of the receiving tank 16. The lower drive spindle 166 extends through a central bottom opening 176 in the receiving tank 16. The lower drive motor 160 may be flange-connected to the receiving tank 16 from below coaxially with the bottom opening 176. The receiving tank 16 may be emptied through a drain port 178 and a drain port 180.
[0109] It is obvious to a person skilled in the art that the embodiments described above are to be understood as exemplary and that the invention is not limited to these embodiments but may be varied in many ways without departing from the scope of protection of the claims. It can also be seen that features disclosed in the description, claims, drawings or otherwise, individually define important components of the invention even if they are described together with other features.
Claims
1. A disc-shaped grinding / polishing machine (10) for plane grinding and / or polishing of a sample surface on the underside, in particular a mounted and / or unmounted sample, by means of a rotating grinding / polishing disc (18), and in particular for preparing a sample for metallographic analysis, the disc-shaped grinding / polishing machine comprising: a grinding / polishing head (30) having a sample holder (34) for inserting one or more samples, The lower housing (12) has a receiving groove (16) for receiving a grinding and / or polishing suspension. A grinding / polishing disc (18) in a receiving groove (16), wherein different grinding pads, polishing pads and / or polishing cloths can be detachably fixed on the upper side (18a) of the grinding / polishing disc (18), so that the lower side of a sample pressed onto the grinding / polishing disc (18) from above can be plane ground and / or polished using the corresponding grinding pads, polishing pads or polishing cloths, an electric first drive motor (60) for the sample holder (34) arranged in the grinding / polishing head (30), an electric second drive motor (160) for the grinding / polishing disc (18) arranged in the lower housing (12), a first drive spindle (66) for driving the sample holder (34) in rotation, wherein the first electric drive motor (60) comprises a first stator (64) and a first rotor (62), wherein the first drive spindle (66) is coaxially connected to the first rotor (62), and the first electric drive motor (60) and the first drive spindle (66) form a coaxial first direct drive (61) for the sample holder (34), and / or A second drive spindle (166) is used to rotationally drive the grinding / polishing disc (18), wherein the electric second drive motor (160) includes a second stator (164) and a second rotor (162), wherein the second drive spindle (166) is coaxially connected to the second rotor (162), and the second electric drive motor (160) and the second drive spindle (166) constitute a coaxial second direct drive device (161) for the grinding / polishing disc (18).
2. The disc grinding / polishing machine (10) according to claim 1, in, The speed of the first electric drive motor (60) is 20 min. -1 With 200min -1 and / or the speed of the second electric drive motor (160) is within the range of 50 min. -1 With 600min -1 in the range between.
3. A disc grinding / polishing machine (10) according to any one of the preceding claims, in, The first and / or second electric drive motor (60, 160) is designed as a synchronous motor, in particular as a torque motor.
4. A disc grinding / polishing machine (10) according to any one of the preceding claims, in, The invention comprises a vertical lifting mechanism (44), by means of which the grinding / polishing head (30) is lowered onto the grinding / polishing disk (18) so as to perform plane grinding and / or polishing on the sample.
5. The disc grinding / polishing machine (10) according to claim 4, in, The lifting mechanism (44) has at least one vertical guide device (52a, 52b), a screw (50) and a screw drive motor (48), wherein the screw drive motor (48) causes the screw (50) to rotate in a screw nut or a circulating guide device (118) to cause the grinding / polishing head (30) to move vertically up and down along the at least one vertical guide device (52a, 52b).
6. The disc grinding / polishing machine (10) according to claim 5, in, The spindle drive motor (48) is designed as a stepper motor with a rotary encoder.
7. The disc grinding / polishing machine (10) according to any one of claims 4 to 6, in, The grinding / polishing head (30) is suspended from a suspension device (32) having a vertical tower portion (42) and a horizontal bridge portion (46). The vertical tower portion (42) is fixed on the equipment support foot (112) and extends vertically upward from the equipment support foot (112). wherein a horizontal bridge portion (46) is suspended on the vertical tower portion (42) and extends horizontally above the lower shell (12) to the grinding / polishing head (30), and wherein the grinding / polishing head (30) is suspended on the end of the bridge portion (46) opposite to the tower portion (42), and / or Therein, a lifting mechanism (44) is arranged in the vertical tower portion (42) and raises and lowers the horizontal bridge portion (46) together with the grinding / polishing head (30) and the coaxial first direct drive device (61).
8. A disc grinding / polishing machine (10) according to any one of the preceding claims, in, The first drive spindle (66) is supported above and below the first rotor (62), wherein the lower bearing (70) is designed as a fixed bearing, in particular having a radial thrust ball bearing or a deep groove ball bearing, and the lower bearing is preloaded, in particular by a wave spring (72).
9. A disc grinding / polishing machine (10) according to any one of the preceding claims, in, The first drive spindle (66) is supported above and below the first rotor (62), wherein the upper bearing (106) is designed as a floating bearing, in particular having a cylindrical roller bearing, in order to absorb axial movements of the first drive spindle (66) relative to the first stator (64).
10. Disc grinding / polishing machine (10) according to any one of the preceding claims, in, The second drive spindle (166) is supported above and below the first rotor (62), in particular by means of angular contact ball bearings or deep groove ball bearings.
11. A disc grinding / polishing machine (10) according to any one of the preceding claims, in, For surface grinding and / or polishing using the center-press method, the sample can be fixedly clamped in a sample holder (34) and a defined contact pressure (F) can be set by advancing the entire grinding / polishing head (30) together with an electric first drive motor (60). A ) is applied as a central pressure on the sample holder (34) via the first drive spindle (66).
12. A disc grinding / polishing machine (10) according to any one of the preceding claims, in, Means for determining a zero point are included which detect contact of the lower surface of the sample with the grinding / polishing disk (18).
13. A disc grinding / polishing machine (10) according to any one of the preceding claims, in, The first drive spindle (66) and the first rotor (62) constitute the first motor shaft of the first drive motor (60), and the first motor shaft having the first drive spindle (66) and the first rotor (62) is axially elastically suspended on the grinding / polishing head (30).
14. The disc grinding / polishing machine (10) according to claim 13, in, When the sample holder (34) is pressed onto the grinding / polishing disc (18), the first motor shaft overcomes the spring stress of the elastic suspension device of the first motor shaft and moves axially elastically relative to the first stator (64), and a force measuring device (80) is included, which measures the force applied by the first motor shaft to the axial elastically resilient suspension device of the first motor shaft.
15. Disc grinding / polishing machine (10) according to any one of the preceding claims, in, A force measuring device (80) is included, which measures the contact pressure (F) acting on the first drive spindle (66) relative to the grinding / polishing head (30). A ), and / or the force measuring device is arranged coaxially with the first electric drive motor (60), and / or coaxially with the first rotor (62).
16. A disc grinding / polishing machine (10) according to any one of the preceding claims, in, A first rotor (62) is suspended axially movably and resiliently relative to a first stator (64), wherein contact pressure on a grinding / polishing disk (18) causes a coaxial movement of the first rotor (62) relative to the first stator (64), and wherein a force measuring device (80) is included which measures the force acting on the resilient suspension device due to the coaxial movement of the first rotor (62) relative to the first stator (64).
17. The disc grinding / polishing machine (10) according to any one of claims 14 to 16, in, The force measuring device (80) comprises at least one force sensor (87), in particular at least one strain gauge (88), which is arranged in particular radially outside the first drive spindle (66).
18. The disc grinding / polishing machine (10) according to any one of claims 14 to 17, in, The force measuring device (80) comprises a force distribution ring (82) which extends around the first drive spindle (66), wherein in the case of a central pressing method, a reaction force (F G ), in particular via a lower bearing (70) of a first drive spindle (66) to a force distribution ring (82), wherein the force distribution ring (82) is axially elastically coupled to a suspension device (32) of a grinding / polishing head (30), and wherein the force measuring device (80) comprises at least one force sensor (87) by means of which a contact pressure (F A ).
19. The disc grinding / polishing machine (10) according to any one of claims 14 to 18, in, A control device is included into which a contact pressure setpoint value can be input, wherein the control device controls a lifting mechanism (44) and defines a closed control loop in which a contact pressure (F) applied by the lifting mechanism (44) on a grinding / polishing disk (18) on a sample holder (34) is increased in response to a contact pressure measurement value measured by a force measuring device (80). A ) is actively regulated to the set contact pressure rating.
20. A disc grinding / polishing machine (10) according to any one of the preceding claims, in, The sample holder (34) is designed as a multi-purpose sample holder having a plurality of sample containers (36), which are arranged around the rotation axis (21) of the first drive spindle (66). The grinding / polishing head (30) has a separate pressing piston (38), and the samples placed in the corresponding sample container (36) are exerted with force by one of the separate pressing pistons (38).
21. The disc grinding / polishing machine (10) according to claim 20, in, The individual pressing pistons (38) are pneumatically operated, The first drive spindle (66) has a compressed air interface (90) for introducing compressed air, wherein an axial compressed air channel (92) extends in the first drive spindle (66), which guides the compressed air axially through the first rotor (62) and the first stator (64) to an air distributor (96) below the first electric drive motor (60), and wherein the air distributor (96) distributes the compressed air radially to the individual pressing pistons (38) via distribution channels (102) in order to pneumatically operate these individual pressing pistons.
22. The disc-shaped grinding / polishing machine (10) according to any one of the preceding claims comprises a horizontal movement mechanism (244) for a grinding / polishing head (30), the grinding / polishing head (30) together with a first electric drive motor (60) and / or a force measuring device (80) and in particular a lifting mechanism (44) for the grinding / polishing head (30) being able to be moved motor-driven transversely to the grinding / polishing disc (18) by means of the movement mechanism.
23. A disc-shaped grinding / polishing machine (10) for plane grinding and / or polishing of a sample surface on the underside of a sample by means of a rotating grinding / polishing disc (18), in particular for preparing a sample, in particular according to any one of the preceding claims, comprising: The lower housing (12) has a receiving groove (16) for receiving a grinding and / or polishing suspension. A horizontal grinding / polishing disc (18) is arranged in a receiving groove (16) and rotates about a vertical rotation axis (20), wherein different grinding pads, polishing pads and / or polishing cloths can be detachably fixed on the upper side (18a) of the grinding / polishing disc (18) so that the lower side of a sample pressed onto the grinding / polishing disc (18) from above can be plane ground and / or polished using corresponding grinding pads, polishing pads or polishing cloths, a grinding / polishing head (30) having a sample holder (34) for inserting one or more samples, a first drive spindle (66) extending vertically in the grinding / polishing head (30), wherein the sample holder (34) is connected to the lower end of the first drive spindle (66) so that the sample holder (34) can be rotationally driven by the first drive spindle (66), an electric first drive motor (60) arranged in the grinding / polishing head (30) for driving a first drive spindle (66) in rotation, The first electric drive motor (60) comprises a first stator (64) and a first rotor (62), wherein a first drive spindle (66) extends coaxially in the first rotor (62), and the first electric drive motor (60) and the first drive spindle (66) form a coaxial first direct drive device (61) for the sample holder (34).
24. The disc grinding / polishing machine (10) according to claim 23, further comprising: An electric second drive motor (160) for the grinding / polishing disc (18) is arranged in the lower housing (12).
25. The disc grinding / polishing machine (10) according to claim 24, further comprising: a second drive spindle (166) extending vertically from the lower housing (12) through a bottom opening (176) of the receiving groove (16) and into the receiving groove (16), wherein the grinding / polishing disc (18) is connected to an upper end portion of the second drive spindle (166) so as to rotationally drive the grinding / polishing disc (18) by means of the second drive spindle (166), The second electric drive motor (160) comprises a second stator (164) and a second rotor (162), wherein a second drive spindle (166) extends coaxially in the second rotor (162), and the second electric drive motor (160) and the second drive spindle (166) form a coaxial second direct drive device (161) for the grinding / polishing disc (18).
26. A disc-shaped grinding / polishing machine (10) for plane grinding and / or polishing of a sample surface on the underside of a sample by means of a rotating grinding / polishing disc (18), in particular for preparing a sample, in particular according to any one of the preceding claims, comprising: The lower housing (12) has a receiving groove (16) for receiving a grinding and / or polishing suspension. A horizontal grinding / polishing disc (18) is arranged in a receiving groove (16) and rotates about a vertical rotation axis (20), wherein different grinding pads, polishing pads and / or polishing cloths can be detachably fixed on the upper side (18a) of the grinding / polishing disc (18) so that the lower side of a sample pressed onto the grinding / polishing disc (18) from above can be plane ground and / or polished using corresponding grinding pads, polishing pads or polishing cloths, a second drive spindle (166), the second drive spindle (166) vertically extending from the lower housing (12) into the receiving groove (16), wherein the grinding / polishing disc (18) is connected to the upper end of the second drive spindle (166) so that the grinding / polishing disc (18) is rotationally driven by the second drive spindle (166), an electric second drive motor (160) arranged in the lower housing (12) for driving the second drive spindle (166) to rotate, The second electric drive motor (160) comprises a second stator (164) and a second rotor (162), wherein a second drive spindle (166) extends coaxially in the second rotor (162), and the second electric drive motor (160) and the second drive spindle (166) form a coaxial second direct drive device (161) for the grinding / polishing disc (18).
27. The disc grinding / polishing machine (10) according to claim 26, further comprising: a grinding / polishing head (30) having a sample holder (34) above the grinding / polishing disk (18) for inserting one or more samples, a first drive spindle (66) extending vertically in the grinding / polishing head (30), wherein the sample holder (34) is connected to the lower end of the first drive spindle (66) so that the sample holder (34) can be rotationally driven by the first drive spindle (66), an electric first drive motor (60) arranged in the grinding / polishing head (30) for driving a first drive spindle (66) in rotation, The first electric drive motor (60) includes a first stator (64) and a first rotor (62), wherein the first drive spindle (66) is coaxially connected to the first rotor (62), and the first electric drive motor (60) and the first drive spindle (66) constitute a coaxial first direct drive device (61) for the sample holder (34).