Motor spindle circular saw

Abstract

A motor spindle circular saw (1) for sawing wood (2) is described, having a rotary drive (3), which comprises an armature (5) and a stator (6), for a rotor (4) which is connected in terms of rotary drive to a saw spindle (7), on which a sawing tool (16) comprising circular saw blades (12) is mounted. In order to permit simple and rapid adjustment of the cutting thickness in spite of a high degree of efficiency and precise cutting conditions, it is proposed that the saw spindle (7) comprises at least two saw spindle units (9a, 9b, 9c) which are connected to one another for conjoint rotation and, on their working side, each have a circular saw blade mount (11) for a circular saw blade (12), wherein at least one saw spindle unit (9a, 9b, 9c) is shiftable along a rotor longitudinal axis (8) relative to the rotor (4) and relative to the other saw spindle unit (9a, 9b, 9c), and wherein the sawing tool (16) formed by the circular saw blades (12) of the respective saw spindle units (9a, 9b, 9c) is floatingly mounted.

Description

[0001] Motor spindle circular saw

[0002] Technical area

[0003] The invention relates to a motor spindle circular saw for sawing wood with a rotary drive comprising an armature and a stator for a rotor which is rotary-drive connected to a saw spindle on which a sawing tool comprising circular saw blades is mounted.

[0004] State of the art

[0005] AT521963B1 discloses a motor-driven circular saw for sawing wood, comprising a saw spindle and a circular saw blade holder. The saw spindle is connected to a rotor via a rotary drive. The rotor itself is driven by a rotary drive comprising an armature and a stator. While the direct arrangement of the armature of the rotary drive on the rotor results in a relatively high efficiency of the motor-driven circular saw, as additional power transmission elements such as intermediate gears or belt drives are obsolete, and also ensures precise cutting guidance, the motor-driven circular saw known from AT521963B1 is designed to support, albeit large, rigid sawing tools and is relatively inflexible with regard to varying cutting thicknesses of the wood to be sawn.In order to adjust the cutting thickness, the entire sawing tool, including all of the circular saw blades, must be changed, which is very time-consuming if it has to be changed frequently.

[0006] Description of the invention The invention is therefore based on the object of improving a motor spindle circular saw of the type described at the outset in such a way that it allows simple and quick cutting thickness adjustment despite a high degree of efficiency and precise cutting conditions.

[0007] The invention achieves this objective in that the saw spindle comprises at least two saw spindle units connected to one another in a rotationally fixed manner, each of which has a circular saw blade holder for a circular saw blade on its working side, wherein at least one saw spindle unit is displaceable along a rotor longitudinal axis, relative to the rotor and relative to the other saw spindle unit, and wherein the sawing tool formed by the circular saw blades of the respective saw spindle units is cantilevered. As a result of the measures according to the invention, the normal distance between the circular saw blades assigned to each saw spindle unit can be adjusted in the direction of the rotor longitudinal axis and fixed in the desired position, so that different thicknesses can be created between the wooden boards during sawing without having to change the entire sawing tool.Due to the rotationally fixed arrangement of the armature of the rotary drive on the rotor for driving the rotor, no additional power transmission elements are necessary, thus enabling a high level of efficiency of the motor spindle circular saw. In a simple embodiment, one saw spindle can be immobile with respect to the rotor's longitudinal axis, and one saw spindle can be displaceable along the rotor's longitudinal axis, relative to the rotor and to the other saw spindle unit, i.e., movable and fixable. Thus, at least one saw spindle unit can be displaced along a rotor's longitudinal axis, relative to the rotor and relative to the other saw spindle unit. Since the rotor is connected to the saw spindle units by a rotational drive and these are connected to one another in a rotationally fixed manner, all circular saw blades of the various saw spindle units have the same angular velocities, thus ensuring extremely precise cutting conditions.The rotationally fixed connection can be achieved, for example, by splines or keys. The rotor itself is preferably fixed in the direction of the rotor's longitudinal axis, i.e., cannot be displaced relative to the machine housing. This is usually ensured by the rotor bearing. The rotor can naturally be displaced together with the machine housing via a bearing block. To cool the rotor, it can have cooling lines, which are preferably supplied with a coolant via a rotary union. The rotary drive (in particular an electric motor or similar with the active parts, namely the armature and stator) with the heavy saw spindle and its high moment of inertia is very advantageous for smoothing out the shock loads that occur during sawing and for preventing the shock loads from being passed on to the electrical system and causing subsequent damage.The sawing tool formed by the circular saw blades of the respective saw spindle units is mounted, in particular, in a floating manner on the saw spindle. The invention also relates to a motor-driven spindle circular saw with circular saw blades arranged on the working-side circular saw blade holders. The working side is understood to be the side of the saw spindle that is not enclosed by the rotor or not located in the housing of the motor-driven spindle circular saw.

[0008] A motor-spindle circular saw that can be adjusted particularly quickly is achieved by having the saw spindle comprise at least two telescopic, particularly concentrically interlocking saw spindle units, each independently displaceable along a rotor longitudinal axis and connected to one another in a rotationally fixed manner. Each of the saw spindle units has a circular saw blade holder for a circular saw blade on the working side. As a result of these measures, the normal distances between the circular saw blades can be adjusted in the direction of the rotor longitudinal axis and fixed in the desired position by displacing both saw spindle units independently of one another, relative to one another, and relative to the rotor, thus enabling even faster displacement options.

[0009] Particularly precise cutting is achieved when the armature is arranged so that it cannot rotate on the rotor and the stator is arranged so that it cannot rotate in a housing between a fixed bearing and a loose bearing of the rotor, with a sawing tool formed by the circular saw blades of the respective saw spindle units being cantilevered on the saw spindle. The armature and rotor can also form a single structural unit. As the rotary drive is located directly on the rotor and external drives that place excessive strain on the saw spindle are thus unnecessary, there is no strong bending stress on the rotor shaft and no resulting deflection of the sawing tool attached to the saw spindle, which allows for particularly clean cutting within tight tolerances and the cantilevered mounting of the sawing tool. This cantilevered mounting of the sawing tool, in turn, enables quick and easy sawing tool changes.

[0010] In order to be able to install the saw spindle with its saw spindle units particularly compactly in the motor spindle circular saw, it is proposed that the rotor forms a hollow shaft in which the at least one saw spindle unit is arranged, which can be displaced along a rotor longitudinal axis relative to the rotor and relative to the other saw spindle unit, and is connected to the rotor in a rotationally fixed manner. In particular, the rotor can form a hollow shaft in which the at least two saw spindle units are arranged, which extend telescopically into one another, are each displaceable independently of one another along the rotor longitudinal axis and are connected to one another in a rotationally fixed manner, wherein the radially outermost saw spindle unit is connected to the rotor in a rotationally fixed manner, namely to the inside of the hollow shaft. The rotor thus specifies the largest diameter of the telescopic saw spindle with its saw spindle units and can thus be installed together with the saw spindle in the motor spindle circular saw.At the same time, the outer surface of the rotor remains free for the rotary drive's armature, allowing the armature to engage the entire surface along the length of the rotor. Due to the direct power transmission from the rotor to the saw spindle units, which are all connected in a rotationally fixed manner, all saw spindle units exhibit the same angular velocity, which further improves cutting conditions and eliminates failure-prone and backlash-prone intermediate gears.

[0011] A particularly stable, insensitive to disturbing bending moments

[0012] Motor spindle circular saw results when the rotor has a

[0013] A circular saw blade holder is connected to a circular saw blade in a rotationally fixed manner. Thus, the rotor itself forms a saw spindle with a circular saw blade, namely the circular saw blade closest to the rotary drive. The bending moments with respect to this nearest circular saw blade are naturally particularly low, so the rotor can also have multiple circular saw blade holders for circular saw blades. The multiple circular saw blades, for example, four, arranged fixedly along the rotor's longitudinal axis, can be combined to form a shredder unit.

[0014] In order to be able to move and lock the saw spindle units as precisely as possible, it is proposed that a hydraulic cylinder be provided for moving the saw spindle units along the rotor's longitudinal axis. Preferably, a hydraulic cylinder can be provided for each saw spindle unit along the rotor's longitudinal axis. In particular, double-acting hydraulic cylinders can be used, each of which accordingly comprises two supply lines for supplying a working medium. Particularly advantageous design conditions arise if the saw spindle units are each formed, at least in sections, by a hydraulic cylinder housing, on the head side of which the circular saw blade holder is arranged. Thus, the hydraulic cylinders themselves form the saw spindle units, which significantly facilitates installation of the saw spindle comprising the saw spindle units without preventing smooth rotation.To determine the position of the saw spindle units, the hydraulic system can be locked. This can be achieved by blocking the flow of hydraulic fluid through the rotary union using valves, particularly servo valves.

[0015] In order to make the saw spindle as robust as possible despite the possibility of precise, independent displacement of the saw spindle units, the telescopically extending saw spindle units can be arranged displaceably along a common piston. In particular, a stepped piston can run along the longitudinal axis of the rotor, with each stepped piston section forming a guide for one of the telescopic saw spindle units, each of which is designed at least partially as a cylinder or hollow shaft, in particular at least partially as a hydraulic cylinder housing. Thus, the saw spindle units, in particular the hydraulic cylinder housings of the respective saw spindle units, share a piston, which can increase the rigidity of the saw spindle unit. The piston or stepped piston can be connected to the rotor in a rotationally fixed manner to prevent frictional heat resulting from relative movement.The different stepped piston sections of the stepped piston differ in their diameters, with the outermost stepped piston section, located at the end facing away from the rotary drive, being the smallest. In the case of a stepped piston, the lengths of the stepped piston sections minus the piston head thickness of the respective stepped piston sections essentially determine the stroke height.

[0016] To ensure precise relocation of the saw spindle units without compromising the compact design of the motor spindle circular saw and without disrupting smooth rotation, it is proposed that the piston, in particular the stepped piston, have flow lines for supplying the saw spindle units and / or the rotor with a working medium. The flow lines can be supplied at one end via a rotary feedthrough unit, preferably comprising multiple rotary feedthroughs, and at the other end can be fluidly connected to the saw spindle units via ring lines. Preferably, the piston or stepped piston has two flow lines per saw spindle unit. In this way, the stroke height of a double-acting hydraulic cylinder serving as a saw spindle unit can be precisely adjusted by fluidly connecting both chambers of the hydraulic cylinder to the rotary feedthrough unit.Hydraulic oil can therefore be used as the working medium. The piston or the stepped piston can also have flow lines that act as cooling lines for cooling the rotor and / or the saw spindle units. A cooling medium can therefore also be used as the working medium. Furthermore, flow lines can be used as lubricant lines. A lubricant can therefore also be used as the working medium. The flow lines are preferably designed as bores. The piston or the stepped piston can preferably also have power lines that are supplied with power via a slip ring transmission. In this way, electrical components on the rotor or on the saw spindle units can be supplied with electricity.

[0017] In order to be able to transmit particularly high power levels, a further development of the invention provides for the rotary drive to be liquid-cooled in order to avoid thermal problems. In addition, the armature, the stator, the fixed bearing and the floating bearing can be liquid-cooled, for which purpose four cooling circuits whose temperatures can be independently controlled by means of temperature control valves are preferably provided. In this way, the thermal effects of the active parts (stator, armature) on the bearings arranged in the same housing as well as the bearing power loss can be absorbed with intelligent liquid cooling. In particular, the rotor can also be liquid-cooled. The flow line carrying the cooling medium can preferably run in the region of its outer surface in the rotor in order to shorten and significantly improve heat transfer.The rotor's flow line can preferably extend to the area of ​​the fixed bearing and serve as a cooling ring for the fixed bearing. In particular, the inner ring of the fixed bearing can be partially surrounded by the cooling medium. This can adequately counteract the large temperature difference between the inner ring and the outer ring, which leads to bearing failures and becomes hotter due to the higher rolling frequency compared to the outer ring, and keep the temperature delta low and consistently below 10 °C.

[0018] To prevent temperatures in the housing from falling below the dew point, the liquid cooling system can also be equipped with a temperature controller and, if necessary, a heater. This ensures thermal geometry and prevents the necessarily preloaded bearings from becoming distorted and damaging them during standstill. To enable particularly efficient cooling of the stator, the stator can be thermally connected to an aluminum cooling ring near the winding heads. The cooling ring, in turn, can form a cooling line for a cooling medium.

[0019] To ensure the desired thickness of the wooden boards can be adjusted with particular precision when sawing the wood, it is proposed that a position measuring sensor connected to a control unit be provided to control the displacement of the saw spindle units. The position measuring sensors can be installed at reference points on the saw spindle units so that their position can be clearly determined. For example, they can be installed in the hydraulic cylinders of the saw spindle units. The hydraulic cylinders themselves can serve as position measuring sensors. The position measuring sensors can be powered via the power lines of the piston or the stepped piston.

[0020] To prevent excessive forces from being exerted on the position sensors, a position probe can be arranged in the center of the piston as a position sensor to detect the position of the saw spindle units. This increases the accuracy of position detection, especially at high rotational speeds. To reduce the radial distance between the permanent magnet ring and the position probe, which is limited for the magnetostrictive function, in this arrangement, supporting magnets can be installed in the non-magnetic piston, especially in stepped pistons, thus halving the radial distance.

[0021] In particular, the spindle saw can be used as a group saw with two motor spindle circular saws according to the invention, wherein the rotor longitudinal axes of the motor spindle circular saws run parallel to each other and are offset from each other in the cutting direction. Furthermore, the two spindle saws, arranged offset in the cutting direction, can have a vertical overlap of several millimeters in the centrifugal circles of the circular saw blades operating in one and the same cutting plane, for clean cutting through the sawn timber. To control the overlap, but in particular to enable the use of different circular saw diameters adapted to the required cutting height and thus also significantly improve the arc-following cut and thus also the efficiency of the entire production plant, the center distance of the rotors of the different motor spindle circular saws can be adjustable using an actuator.The spindle saws according to the invention can be used in particular in a so-called apex arrangement, i.e. in a vertical apex plane, in which a longitudinal axis of the entire machine chain and thus also the cutting direction lies, left and right versions of the spindle saw are each mirrored opposite each other and can process the log transported along the cutting direction in phases to the right and left of the apex plane.

[0022] Brief description of the invention

[0023] The drawing shows an example of the subject matter of the invention.

[0024] Fig. 1 a full section through the motor spindle circular saw according to the invention in perspective view,

[0025] Fig. 2 shows a schematic section through a saw spindle according to the invention on a larger scale,

[0026] Fig. 3 is a side view of a group saw comprising two motor spindle circular saws according to the invention and

[0027] Fig. 4 a full section through the motor spindle circular saw in side view.

[0028] Ways to implement the invention

[0029] A motor spindle circular saw 1 according to the invention for sawing wood 2 has, as can be seen in particular from Fig. 1, a rotary drive 3 for a rotor 4. The rotary drive 3, for example an electric motor, comprises an armature 5 and a stator 6 as active units. The rotor 4 is connected to a saw spindle 7 in a rotary drive manner. According to the invention, the saw spindle 7 comprises at least two, for example three, non-rotatably connected saw spindle units 9a, 9b, 9c, wherein at least one saw spindle unit 9a, 9b, 9c is displaceable along a rotor longitudinal axis 8, relative to the rotor 4 and relative to the other saw spindle units 9a, 9b, 9c. The saw spindle 7 preferably comprises at least two, for example three, telescopic, in particular concentrically extending saw spindle units 9a, 9b, 9c, each of which is independently displaceable along a rotor longitudinal axis 8, fixable and connected to one another in a rotationally fixed manner.Each saw spindle unit 9a, 9b, 9c has a circular saw blade holder 11 for a circular saw blade 12 on the side facing away from the rotor, preferably in the region of its head sides 10a, 10b, 10c facing away from the rotor, i.e., on the working side. In this way, the normal spacing of the circular saw blades 12 can be easily varied, allowing the board thicknesses of a piece of wood 2 to be processed to be adjusted and optimized.

[0030] The armature 5 is mounted on the rotor 4 in a rotationally fixed manner. The stator 6 can be arranged in a rotationally fixed manner in a housing 13 between a fixed bearing 14 and a floating bearing 15 of the rotor 4. The sawing tool 16 formed by the circular saw blades 12 of the respective saw spindle units 9a, 9b, 9c can be cantilevered on the saw spindle 7. This arrangement of the rotor 4 prevents excessive bending stress on the rotor shaft. The cantilevered mounting of the sawing tool 16 enables quick and easy sawing tool changes. This can be achieved, for example, by unscrewing the circular saw blade holders 11 from the associated saw spindle units 9a, 9b, 9c.

[0031] Particularly compact conditions with regard to telescoping arise, as shown in Figs. 1 and 2, when the rotor 4 forms a hollow shaft. In this hollow shaft, i.e. in the interior of the hollow rotor 4, at least two, for example three, saw spindle units 9a, 9b, 9c can be arranged. The radially outermost saw spindle unit 9a can be connected in a rotationally fixed manner to the rotor, i.e. to the inside of the hollow rotor 4. Since the saw spindle units 9a, 9b, 9c are also connected in a rotationally fixed manner to one another, the torque is transmitted from the armature 5, via the rotor 4, via the radially outermost saw spindle unit 9a to the radially inner saw spindle units 9b, 9c. The rotationally fixed connection can be realized, for example, via splines or keys.

[0032] The rotor 4 itself can have a circular saw blade holder 11, so that it can also be connected in a rotationally fixed manner to a circular saw blade 12. In particular, the rotor 4 can have several circular saw blade holders 11 that are not adjustable along the rotor's longitudinal axis 8, for example, four. The circular saw blades 12 arranged on the non-adjustable circular saw blade holders 11 of the rotor 4 can form a shredding unit 17.

[0033] Hydraulic cylinders 18 can be provided for displacing the saw spindle units 9a, 9b, 9c along the rotor's longitudinal axis 8. In particular, the saw spindle units 9a, 9b, 9c can each be formed, at least in sections, by a hydraulic cylinder housing 19a, 19b, 19c, so that the hydraulic cylinder housings 19a, 19b, 19c can form the shafts of the saw spindle units 9a, 9b, 9c. The circular saw blade holders 11 can be arranged on their respective head sides 10a, 10b, 10c.

[0034] A compact design when designing the saw spindle units 9a, 9b, 9c as hydraulic cylinders results from the fact that the telescopically extending saw spindle units 9a, 9b, 9c are arranged displaceably along a common piston 20, which runs concentrically to the rotor's longitudinal axis 8. For this purpose, the piston 20 can be designed as a stepped piston. The stepped piston has a stepped piston section 21a, 21b, 21c for each saw spindle unit 9a, 9b, 9c, which forms a guide for one of the saw spindle units 9a, 9b, 9c, each of which is designed at least in part as a hollow shaft. If the saw spindle units 9a, 9b, 9c are designed as hydraulic cylinders, the stepped piston sections 21a, 21b, 21c form a guide for the hydraulic cylinder housings 19a, 19b, 19c of the saw spindle units 9a, 9b, 9c.The stepped piston sections 21a, 21b, 21c of the stepped piston 20 differ in their diameters, which remain constant over the length of the respective stepped piston section 21a, 21b, 21c, with the diameter of the outermost stepped piston section 21c, located at the end facing away from the rotary drive 3, being the smallest. The diameters of the subsequent stepped piston sections 21a, 21b, 21c increase in steps.

[0035] As illustrated in Fig. 2, the piston 20 can have flow lines 22 for supplying the saw spindle units 9a, 9b, 9c and / or the rotor 4 with a working medium. The flow lines 22 can be supplied at one end via a rotary feedthrough unit 27. At the other end, the flow lines 22 can be fluidly connected to the saw spindle units 9a, 9b, 9c via ring lines. If the saw spindle units 9a, 9b, 9c are designed as double-acting hydraulic cylinders 18, the stepped piston 20 can have two flow lines 22 per saw spindle unit 9a, 9b, 9c, with one flow line 22 leading into the first chamber of the hydraulic cylinder and the other flow line leading into the other chamber of the hydraulic cylinder.The flow lines 22, which can be designed as bores distributed around the circumference of the piston 20, can also be used for cooling and / or lubricating the rotor 4 or the saw spindle units 9a, 9b, 9c. Furthermore, the piston 20 can form power lines that are supplied with power via a slip ring transmission. The power lines can also be routed in the flow lines 22, in which case they are not supplied with a working medium.

[0036] Fig. 2 indicates that for the precise determination of the position of the saw spindle units and thus for controlling their displacement, position measuring sensors 23 can be provided, which are signal-connected to a control unit 24. The position measuring sensors 23 can be supplied with power via power lines of the piston 20.

[0037] Fig. 3 shows a group saw with two motor spindle circular saws 1 according to the invention. The rotor longitudinal axes 8 of the motor spindle circular saws 1 run parallel to one another and, in this case, into the plane of the drawing. The rotor longitudinal axes 8 are also offset from one another in the cutting direction 25, predetermined by a conveyor 26. In addition, the spindle saws 1 can have a vertical overlap of the centrifugal circles predetermined by the circular saw blades 12 of the circular saw blades operating in the same cutting plane. To control the overlap, the center distance A of the rotors 4 of the different motor spindle circular saws 1 can be adjustable using an actuator. Fig. 4 shows that a position probe can be arranged as a displacement sensor 23 in the center of the piston 20 to detect the position of the saw spindle units 9a, 9b, 9c.In order to reduce the radial distance of the permanent magnet ring from the position probe, which is limited for the magnetostrictive function, in this arrangement, support magnets can be installed in the preferably anti-magnetic piston 20, in particular stepped piston, which thus.

[0038] Halve the radial distance. It can also be seen from Fig. 4 that the flow line 22 can extend in the rotor 4 to the area of ​​the fixed bearing 14. In particular, the bearing inner ring 28 of the fixed bearing 14 can also be fluidly connected to the flow line 22. This allows the temperature of the bearing inner ring 28 to be kept sufficiently low and constant below 10 °C.

Claims

Patent claims 1 . Motor spindle circular saw (1) for sawing wood (2), with a rotary drive (3) comprising an armature (5) and a stator (6) for a rotor (4), which is connected in a rotary drive manner to a saw spindle (7) on which a sawing tool (16) comprising circular saw blades (12) is mounted, characterized in that the saw spindle (7) comprises at least two saw spindle units (9a, 9b, 9c) which are connected to one another in a rotationally fixed manner and which each have a circular saw blade holder (11) for a circular saw blade (12) on their working side, wherein at least one saw spindle unit (9a, 9b, 9c) is displaceable along a rotor longitudinal axis (8), relative to the rotor (4) and relative to the other saw spindle unit (9a, 9b, 9c), and wherein the saw blades (12) of the respective saw spindle units (9a, 9b, 9c) is mounted in a floating manner.

2. Motor spindle circular saw (1) according to claim 1, characterized in that the saw spindle (7) comprises at least two telescopic, in particular concentrically extending saw spindle units (9a, 9b, 9c), each of which is independently displaceable along a rotor longitudinal axis (8) and connected to one another in a rotationally fixed manner, each of which has a circular saw blade holder (11) for a circular saw blade (12) on the working side.

3. Motor spindle circular saw (1) according to claim 1 or 2, characterized in that the rotor (4) forms a hollow shaft in which the at least two saw spindle units (9a, 9b, 9c) are arranged, which extend telescopically into one another, are each displaceable independently of one another along the rotor longitudinal axis (8) and are connected to one another in a rotationally fixed manner, wherein the radially outermost saw spindle unit (9a) is connected to the rotor (4) in a rotationally fixed manner.

4. Motor spindle circular saw (1) according to one of claims 1 to 3, characterized in that the rotor (4) is connected in a rotationally fixed manner to a circular saw blade (12) via a circular saw blade holder (11).

5. Motor spindle circular saw (1) according to one of claims 1 to 4, characterized in that a hydraulic cylinder (18) is provided for displacing the saw spindle units (9a, 9b, 9c) along the rotor longitudinal axis (8).

6. Motor spindle circular saw (1) according to one of claims 1 to 5, characterized in that the saw spindle units (9a, 9b, 9c) are formed at least in sections by a hydraulic cylinder housing (19a, 19b, 19c) on the head side (10a, 10b, 10c) of which the circular saw blade holder (11) is arranged.

7. Motor spindle circular saw (1) according to one of claims 2 to 6, characterized in that the telescopically extending saw spindle units (9a, 9b, 9c) are arranged displaceably along a common piston (20).

8. Motor spindle circular saw (1) according to one of claims 1 to 7, characterized in that a stepped piston (20) runs along the rotor longitudinal axis (8), each stepped piston section (21 a, 21 b, 21 c) forming a guide for one of the telescopic saw spindle units (9a, 9b, 9c), each of which is designed at least in sections as a cylinder.

9. Motor spindle circular saw (1) according to claim 7 or 8, characterized in that the piston (20), in particular the stepped piston, has flow lines (22) for supplying the saw spindle units (9a, 9b, 9c) and / or the rotor (4) with a working medium.

10. Motor spindle circular saw (1) according to one of the preceding claims, characterized in that a position measuring sensor (23) signal-connected to a control unit (24) is provided to control the displacement of the saw spindle units (9a, 9b, 9c).

11. Motor spindle circular saw (1) according to one of claims 8 to 10, characterized in that a position probe is arranged as a displacement sensor (23) in the center of the piston (20) for detecting the position of the saw spindle units (9a, 9b, 9c).

12. Group saw with two motor spindle circular saws (1) according to one of the preceding claims 1 to 11, wherein the rotor longitudinal axes (8) of the motor spindle circular saws (1) run parallel to one another and are offset from one another in the cutting direction (25).

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