Drive device for the central rotary drive of a shaft-like workpiece arranged in a longitudinal axis, machine tool and method for this purpose

Abstract

The present invention relates to a drive device (1) for the central rotary drive of a shaft-like workpiece (5) arranged in a longitudinal axis (L), comprising a drive unit (10) with a housing (20), and a drive ring (30) rotatable about a longitudinal axis (L) by the drive unit (10), which can surround a receiving area (15) in which the workpiece (5) can be arranged for machining, and wherein the drive ring (30) is multi-part in a rotational direction about the longitudinal axis (L) and comprises at least two drive ring sections (31a, 31b) which can be arranged in an open position in which the receiving area (15) is accessible perpendicular to the longitudinal axis (L) and in a closed position in which the receiving area (15) is closed about the longitudinal axis (L), and wherein the drive ring (30) has at least one driver (40a, 40b) for transmitting the rotation of the drive ring (30) to the workpiece (5) has.

Description

[0001] The present invention relates to a drive device for centrally driving a shaft-like workpiece rotated about a longitudinal axis with the features of claim 1, a machine tool with such a drive device with the features of claim 24 and a method for centrally driving a shaft-like workpiece rotated about a longitudinal axis for machining with the features of claim 25.

[0002] A variety of drive devices for the rotary drive of a shaft-like workpiece during machining are known from the prior art. Such drive devices are known, for example, as center-drive machines and are used for machining rotaryally driven workpieces at both ends in a single setup. These center-drive machines have clamping devices that hold the workpiece clamped in the spindle axis. For example, a center-drive machine is known from DE 103 49 432 B3.

[0003] The center-drive machine has a headstock with a spindle driven in one axis by a spindle drive. The spindle includes a receiving area into which the workpiece can be inserted and held by force clamping. Furthermore, the center-drive machine includes at least one tool on each of two opposite sides of the headstock along the machine axis, enabling the simultaneous machining of the two opposite ends of the workpiece.

[0004] These drive devices have proven their worth in the past. However, loading the drive devices with the workpiece requires considerable space to allow the workpiece to be inserted lengthwise. This space requirement is at least equal to the maximum length of the workpieces to be machined. This can lead to a disproportionately large space requirement, especially with particularly long workpieces. Such particularly long components include, for example, shafts, especially crankshafts, with lengths between 0.5 m and 5 m.

[0005] Typically, long workpieces are driven at their ends. Machining the opposite ends of the workpiece in a single clamping operation was not possible. Instead, the workpiece had to be re-clamped and painstakingly aligned within the machine tool, resulting in significant machine downtime and costs.

[0006] This is where the present invention comes in.

[0007] The present invention is dedicated to the task of providing a suitably improved drive device that can be equipped in a simplified manner and enables machining, in particular simultaneous machining of the opposite ends of a workpiece, especially a very long workpiece with a length of over 1 m, preferably over 2 m, and even more preferably over 3 m.

[0008] These tasks are solved by a drive device for the central rotary drive of a shaft-like workpiece arranged in a longitudinal axis with the features of claim 1 and by a method for the central drive of a shaft-like workpiece rotated about a longitudinal axis for machining with the features of claim 24.

[0009] Further advantages are specified in the subclaims.

[0010] The drive device according to the invention for the central rotary drive of a shaft-like workpiece arranged in a longitudinal axis, comprising the features of claim 1, includes a drive unit and a housing. Furthermore, the drive device according to the invention includes a drive ring rotatable about the longitudinal axis by the drive unit, which can surround a receiving area in which the workpiece can be positioned for machining. The drive ring can be mounted on the housing – as will be explained in detail later – and can be set into rotation about the longitudinal axis by the drive unit.

[0011] Furthermore, the drive ring is multi-part in a rotational direction around the longitudinal axis and comprises at least two drive ring sections.

[0012] The at least two drive ring sections form subsections of the drive ring, preferably two, more preferably of equal size, semi-ring-shaped subsections are provided, which form the drive ring. The at least two drive ring sections each form one half of the drive ring.

[0013] The at least two drive ring sections can be arranged in an open position in which the receiving area is accessible perpendicular to the longitudinal axis. In this open position, the receiving ring is open and the workpiece can be inserted into or removed from the receiving area in a direction essentially perpendicular to the longitudinal axis.

[0014] Furthermore, the at least two drive ring sections can be arranged in a closed position, in which the receiving area is closed around the longitudinal axis. In this open position, the receiving ring is closed and can rotate around the longitudinal axis.

[0015] Furthermore, the drive ring can have at least one driver configured to transmit the rotation of the drive ring to the workpiece – preferably by positive, force, and / or frictional engagement. The driver preferably comes into operative contact with the workpiece inserted into the receiving area in the closed position and transmits the rotational movement of the receiving ring to the workpiece.

[0016] The present invention is based on the idea of ​​not inserting the workpiece into the drive device along its longitudinal axis, as in the prior art, but rather proposing a type of openable central drive machine that allows the workpiece to be inserted transversely to its longitudinal axis. This reduces setup times and significantly lowers the space requirement.

[0017] The receiving ring can be opened by arranging the at least two drive ring sections in the open position, and the workpiece to be machined can be inserted – preferably from above – into the receiving ring of the drive device. Subsequently, the receiving ring can be closed by arranging the at least two drive ring sections in the closed position and rotated by the drive device, whereby the drive element transmits the rotation to the workpiece, and the end faces of the workpiece opposite each other along the longitudinal axis can preferably be machined.

[0018] Furthermore, it has proven advantageous if, in the open position, an insertion opening is formed between at least one of the free ends of the at least two drive ring sections, allowing the workpiece to be inserted into the receiving area in a direction perpendicular to the longitudinal axis. The width of the insertion opening preferably corresponds to at least the width or diameter of the workpiece to be machined. Advantageously, the insertion opening is sufficiently wide to allow the workpiece to be easily inserted into the drive device without the risk of collision and resulting damage.

[0019] Furthermore, it has proven advantageous if the drive ring has an inner diameter, and if the width of the insertion opening in the open position approximately corresponds to the inner diameter of the drive ring. The inner diameter of the drive ring defines the maximum width or diameter of the workpiece to be machined.

[0020] A further development of the present invention provides that the drive ring is rotatably supported on the housing. For example, the housing can have bearing means, wherein the bearing means can, for example, comprise one or more rolling and / or sliding bearings.

[0021] A preferred embodiment provides that the drive ring is supported on the housing by rolling bearings. For example, several bearing elements can be arranged distributed around the longitudinal axis, with the bearing elements preferably supporting the drive ring axially and / or radially.

[0022] Preferably, at least two bearing elements are provided on the drive ring, wherein the at least two bearing elements are arranged along the longitudinal axis on opposite sides of the drive ring. Even more preferably, the at least two bearing elements are in operative contact with the drive ring via conical surfaces, thereby enabling both axial and radial bearing support.

[0023] It has also proven advantageous for the drive ring to include teeth. The drive ring can be driven by the drive unit via these teeth. For example, the teeth can be designed as external teeth encircling the drive ring.

[0024] Furthermore, it has proven advantageous if the drive device includes a drive belt. The drive belt can preferably be a toothed belt, which preferably engages with the previously described external teeth of the drive ring. The use of a drive belt reduces vibrations, which is particularly advantageous if the manufacturing process applied to the workpiece is a grinding process.

[0025] Furthermore, it is advantageous if the drive belt engages with the drive ring in a specific engagement area, wherein the engagement area surrounds the drive ring by less than 360°, preferably less than 270°, and even more preferably less than 180° in the direction of rotation. In other words, the drive belt does not encircle the drive ring or the spindle as in conventional center-drive machines, but rather the drive belt is held on one side of the drive ring. Even more preferably, the drive belt is arranged on the side of the drive ring opposite the insertion opening.

[0026] A further development of the present invention provides that the drive device comprises at least one deflection pulley. Preferably, the drive belt is held in operative contact with the drive belt by the at least one deflection pulley.

[0027] A further development of the present invention provides that at least two deflection pulleys define the engagement area. For example, it can be advantageous if the at least two deflection pulleys are arranged on opposite sides of the drive ring and the drive ring is in operative contact with the drive belt between the at least two deflection pulleys. In the preferred embodiment, the drive belt can roll along the at least two deflection pulleys with its inner side and interact with the drive ring with its outer side.

[0028] A further development of the present invention provides that the housing includes a guide ring, and that the drive ring is rotatably mounted in the guide ring. The guide ring preferably completely surrounds the drive ring around its entire circumference. The aforementioned bearing means allow the drive ring to rotate within the guide ring.

[0029] The guide ring may have a radial groove, and the drive ring may be at least partially arranged in the radial groove. The bearing elements may be arranged in the radial groove.

[0030] Furthermore, sealing agents may be provided to prevent the ingress of contaminants into the area between the drive ring and the guide ring. For example, sealing air may be used to prevent contaminants from entering the housing.

[0031] According to a preferred embodiment of the present invention, the guide ring is formed in multiple parts in the direction of rotation about the longitudinal axis and comprises at least two guide ring sections. Preferably, the at least two drive ring sections correspond to the at least two guide ring sections. In other words, it is preferred if the at least two drive ring sections and the at least two guide ring sections extend over circular arcs of equal size, for example, each over a circular arc of 180°.

[0032] For example, it may be advantageous if the at least two guide ring sections form subsections of the guide ring in the direction of rotation, and even more preferably these subsections are provided as two semi-ring-shaped subsections which together form a complete ring-shaped guide ring.

[0033] A preferred embodiment of the present invention provides that the drive device includes an actuating device. The actuating device preferably moves at least one of the at least two guide ring sections of the guide ring and / or at least one of the at least two drive ring sections to switch between the open and closed positions.

[0034] For example, it can be advantageous if one of the at least two guide ring sections, together with one of the at least two drive ring sections, is moved away from the other guide ring section and the other drive ring of the at least two drive ring sections in order to form the insertion opening between the free ends of the respective at least two guide ring sections and at least two drive ring sections. The other of the at least two guide ring sections and the other drive ring of the at least two drive ring sections can be fixed in place.

[0035] In other words, one of the at least two guide ring sections can be fixed in place and the other of the at least two guide ring sections can be pivoted or moved away together with one of the at least two drive ring sections to move into the open position.

[0036] It can also be advantageous if both the at least two guide ring sections and the at least two drive ring sections of the drive ring are moved apart by the actuating device in order to form the insertion opening between the free ends of the respective drive ring sections. Preferably, the actuating device can either move the drive ring sections linearly or pivot them, as will be explained in more detail later.

[0037] Furthermore, it has proven advantageous if at least one of the at least two guide ring sections of the guide ring, together with at least one of the at least two drive ring sections of the drive ring, is pivoted by the actuating device about at least one axis, preferably about a common axis, in order to move from the open position to the closed position and back. The common axis can, for example, be formed by a pivot joint on the guide ring, with the common axis preferably being arranged on the side diametrically opposite the insertion opening in the open position. In other words, the guide ring and the drive ring are folded out from the open position to the closed position.

[0038] An advantageous embodiment of the present invention provides that the drive device has a locking device by which the drive ring can be blocked relative to the guide ring, particularly in the open position. The locking device is preferably configured such that, particularly in the open position, the drive ring section arranged in the respective guide ring section is held immovably.

[0039] Before the drive ring and guide ring open, i.e., before the change from the closed to the open position, the locking device can lock the respective drive ring section relative to the respective guide ring section, preferably fixing the respective drive ring section in a predetermined position on the respective guide ring section. Preferably, the predetermined position corresponds to the position when the free ends of the guide ring sections of the guide ring and the drive ring are aligned or approximately aligned.

[0040] A further development of the present invention provides that the at least one driver is interchangeable. This allows the driver to be easily adapted to workpieces of different shapes.

[0041] Furthermore, it has proven advantageous to provide at least two drive lugs that can fork-like encircle the workpiece inserted into the receiving area. For example, one of the at least two drive lugs serves to transfer the rotary motion of the drive ring to the workpiece during normal operation. The other of the at least two drive lugs primarily serves a safety function to prevent uncontrolled rotation of the workpiece, e.g., during an emergency stop.

[0042] It is particularly advantageous if the at least two drive ring sections of the drive ring each have at least one driver. When switching between the open and closed positions, the workpiece can be positioned between the at least two drivers in a positive fit.

[0043] According to a further advantageous embodiment of the present invention, at least one of the at least two drivers is spring-loaded in the direction of rotation. A spring force determines the clamping force with which the workpiece is held between the at least two drivers. This prevents any vibrations.

[0044] Furthermore, the inclusion of a support unit has proven advantageous. This support unit is configured to support the workpiece along its longitudinal axis, thus preventing, for example, gravity-induced deflection. The support unit is preferably positioned at a distance along its longitudinal axis from the drive ring.

[0045] A further development of the present invention provides that the support unit is height-adjustable perpendicular to the longitudinal axis to adapt to different workpiece diameters. It can also be advantageous if the support unit is replaceable or partially replaceable in order to adapt it to different workpieces.

[0046] Another aspect of the present invention relates to a machine tool, in particular a machine tool for machining, with a drive device described above.

[0047] A further development of the present invention provides that the drive device is arranged to be displaceable at least along the longitudinal axis. The drive device can thus be displaced relative to the machine tool along the longitudinal axis and can therefore be arranged in a workpiece-specific manner.

[0048] Preferably, fastening means are provided by which the drive device can be fixed in a desired position on the machine tool.

[0049] Another aspect of the present invention relates to a method for the central rotary drive of a shaft-like workpiece arranged in a longitudinal axis by means of a drive device, in particular a drive device as previously described. The drive device comprises a drive ring rotatable about a longitudinal axis, which can enclose a receiving area about the longitudinal axis and which has at least one driver, wherein the drive ring comprises at least two drive ring sections in a rotational direction about the longitudinal axis. The method according to the invention comprises the following process steps: - Opening the drive ring by moving at least one of the at least two drive ring sections of the drive ring into an open position in which the receiving area is accessible in a direction perpendicular to the longitudinal axis; - Inserting the workpiece into the receiving area; - Closing the drive ring by moving at least one of the at least two drive ring sections of the drive ring into a closed position in which the receiving area is enclosed; - Rotating the drive ring and transferring the rotary motion to the workpiece via the at least one driver.

[0050] A preferred embodiment of the method provides that the drive ring is opened by a pivoting movement about an axis. This pivoting movement moves the two free ends of the at least two drive ring sections apart in the open position to form an insertion opening. The workpiece can then be inserted into the receiving area through this insertion opening in a direction substantially perpendicular to the longitudinal axis.

[0051] In a further development, it can be advantageous if, when closing the drive ring, the workpiece is arranged between at least two drivers, and preferably, the workpiece is clamped between the at least two drivers. It can be advantageous if at least one of the at least two drivers is spring-loaded in the direction of rotation, with the spring providing the clamping force for holding the workpiece.

[0052] Two exemplary embodiments of a drive device are described in detail below with reference to the accompanying figures. The figures show: Fig. 1 a highly simplified representation of a machine tool with a drive device according to a first embodiment in a closed state, Fig. 2 a simplified side view of the drive device according to Fig. 1 in the closed state, Fig. 3 an isometric representation of the drive device according to the Fig. 1 and Fig. 2, Fig. 4 a simplified view of a drive device according to Fig. 1 in an open state, Fig. 5 an isometric representation of the drive device according to Fig. 4 in the open state, Fig. 6 a sectional view of the drive device according to the section line AA in Fig. 2, Fig. 7 a sectional view of the drive device according to the section line BB in Fig. 2, Fig. 8 a simplified side view of a drive device according to a second embodiment in the closed state, Fig. 9 a perspective view of the drive device according to Fig. 8, and Fig. 10 a perspective view of the drive device according to the second embodiment in the open state.

[0053] Identical or functionally equivalent parts or features are identified by the same reference numerals in the detailed description of the figures below. Likewise, not all identical or functionally equivalent parts or features in the figures are assigned a reference number.

[0054] Fig. Figure 1 shows a highly simplified and schematic representation of an exemplary machine tool 2 for machining a shaft-like workpiece 5. The machine tool 2 according to Fig. 1 comprises a drive device 1 for the central rotary driving of the shaft-like workpiece 5 arranged in a longitudinal axis L according to a first exemplary embodiment.

[0055] The machine tool 2 can, for example, be a machine tool 2 for machining. The machine tool 2 can have at least one tailstock 3, 4, by which the long workpiece 5 can be held in the longitudinal axis L, for example, with a center point that engages in the center bore provided in the face of the workpiece. As in Fig. As indicated in 1, a tailstock 3, 4 can be arranged on each of two opposite sides in order to be able to machine, for example, the ends of the workpiece 5 that are opposite each other in the longitudinal axis L.

[0056] The workpiece 5 can - as the Fig. 5 can be removed - a crankshaft or the like, and can have a length in the longitudinal axis of 0.5 m to approximately 5 m. Such shaft-like workpieces 5 are, for example, crankshafts of large engines.

[0057] Fig. Figure 2 shows a simplified side view of the drive device 1 according to Fig. 1. The drive device 1 can be opened and closed to allow the workpiece 5 to be inserted into the drive device 1. The closed state of the drive device 1 is indicated in the Fig. 1-3 are shown and the open state is in the Fig. 4 and Fig. 5 shown.

[0058] The drive device 1 comprises a housing 20 and a drive ring 30 rotatable about the longitudinal axis L.

[0059] The drive ring 30 can be driven by a drive device 10 and surrounds a receiving area 15 in which the workpiece 5 can be arranged for machining.

[0060] The drive ring 30 is rotatably mounted on the housing 20 and arranged coaxially to the longitudinal axis L. The drive ring 30 has an inner diameter DI.

[0061] Furthermore, it can be seen from the figures that the drive ring 30 is formed in multiple parts in the direction of rotation around the longitudinal axis L. In the illustrated exemplary embodiment, the drive ring 30 comprises two drive ring sections 31a, 31b, which for better understanding will subsequently also be referred to as the first drive ring section 31a and the second drive ring section 31b.

[0062] The two drive ring sections 31a, 31b are preferably equal-sized, semi-circular segments that preferably extend over a circular arc of 180° around the longitudinal axis L. The two drive ring sections 31a, 31b form the drive ring 30.

[0063] The two drive ring sections 31a, 31b can be arranged in the open position, as will be described in detail later, in which the receiving area 15 is accessible perpendicular to the longitudinal axis L, see Fig. 4 and Fig. 5. The two drive ring sections 31a, 31b can also be arranged in the closed position, in which the receiving area 15 is closed around the longitudinal axis, see Fig. 1-3.

[0064] The two drive ring sections 31a, 31b each have a free end 34a, 34b and an end 35a, 35b.

[0065] Preferably, the free end 34a of the first drive ring section 31a and the free end 34b of the second drive ring section 31b are in contact with each other in the closed state, see for example Fig. 2.

[0066] In the open position according to the Fig. 4 and Fig. 5 the two drive ring sections 31a, 31b are arranged such that an insertion opening 32 is formed between the two free ends 34a, 34b, through which the workpiece 5 can be inserted into the receiving area 15 essentially perpendicular to the longitudinal axis L.

[0067] The insertion opening 32 preferably has a width B, wherein the width B preferably corresponds to the smallest distance between the two free ends 34a, 34b in the open position. Since the width B limits the width or diameter of the workpiece 5 to be machined, it is advantageous if the insertion opening 32 is sufficiently wide to allow the respective workpiece 5 to be comfortably inserted into the drive device 1 without the risk of collision and resulting damage.

[0068] The width B of the insertion opening 32 in the open position preferably corresponds approximately to the inner diameter DI of the drive ring 30.

[0069] The Fig. 6 and Fig. Figure 7 shows that the drive ring sections 31a, 31b can be connected at their respective ends 35a, 35b by means of a joint 37. In other words, the end 35a of the first drive ring section 31a and the end 35b of the second drive ring section 31b are connected by means of a joint 37.

[0070] The joint 37 has a rotation axis X, wherein the drive ring sections 31a, 31b can be rotated or pivoted about the rotation axis X in order to be arranged from the closed state to the open state to form the insertion opening 32 and back.

[0071] The drive ring 30 comprises a toothed section 33. The drive ring 30 can be driven by a drive device 10 via the toothed section 33. The toothed section 33 is designed as an external toothing that surrounds the drive ring 30, the tooth profile being, for example, a trapezoidal, circular, involute, or parabolic profile.

[0072] The drive ring 30 also has at least one driver 40a, 40b, which serves to transmit the rotation of the drive ring 30 to the workpiece 5.

[0073] The accompanying figures show that two drivers 40a, 40b are provided, wherein the first drive ring section 31a has the first driver 40a and the second drive ring section 31b has the second driver 40b.

[0074] The respective driver 40a, 40b projects from the drive ring 30 into the receiving area 15 and comes into operative contact with the workpiece 5 inserted into the receiving area 15 to transmit the rotational movement of the drive ring 30 to the workpiece 5.

[0075] The drive element 40 can be completely or partially interchangeable. This allows the drive element 40 to be easily adapted to differently shaped workpieces 5.

[0076] As the exemplary embodiment shown in the accompanying figures illustrates, several drivers 40a, 40b can be provided. In this case, a first driver 40a and a second driver 40b are provided, which can fork-like encompass the workpiece 5 inserted into the receiving area 15.

[0077] For example, one of the at least two drivers 40a, 40b serves to transfer the rotary motion of the drive ring 30 to the workpiece 4 for machining the workpiece 5. The other of the at least two drivers 40a, 40b essentially serves a safety function to prevent uncontrolled rotation of the workpiece, for example in the event of an emergency stop.

[0078] At least one of the two drivers 40a, 40b can be spring-loaded in the direction of rotation on the drive ring 30. This allows, for example, the workpiece 5 to be clamped between the two drivers 40a, 40b.

[0079] The first driver 40a can be arranged on the first drive ring section 31a, particularly in the region of the end 35a. The second driver 40b can be arranged on the second drive ring section 31b, particularly in the region of the end 35b. When changing from the open to the closed state, the drivers 40a and 40b pivot together with the drive ring sections 31a and 31b and can engage the workpiece 5 in a positive locking motion in order to guide the workpiece 5 in a controlled manner in both directions of rotation as described above.

[0080] The housing 20 further comprises a guide ring 50, wherein the drive ring 30 is rotatably mounted in the guide ring 50 about the longitudinal axis L. As shown in the accompanying figures, the guide ring 50 can completely surround the drive ring 30 over its entire circumference.

[0081] The guide ring 50 can have a radial groove 56 on an inner cylindrical surface, into which the drive ring 30 is at least partially inserted. By means of appropriate bearing means 52 (see Fig. 8 and Fig. 9) the drive ring 30 can be rotatably mounted in the guide ring 50, the bearing means 52 comprising plain and / or rolling bearings.

[0082] Furthermore, sealing agents (not shown) can be used to prevent the ingress of contaminants into the housing 20, particularly during the machining of the workpiece 5. These sealing agents can, for example, be sealing air.

[0083] The guide ring 50 is, as especially the Fig. 4 and Fig. 5, which can be removed, is formed in multiple parts in the direction of rotation around the longitudinal axis L and can – as shown – have two guide ring sections 51a, 51b. For better understanding, the two guide ring sections 51a, 51b are subsequently also referred to as the first guide ring section 51a and the second guide ring section 51b.

[0084] The two guide ring sections 51a, 51b are preferably of the same size and semi-circular segments, each preferably extending over a circular arc of 180° around the longitudinal axis L. The two guide ring sections 51a, 51b form the drive ring 30.

[0085] Each guide ring section 51a, 51b has a free end 54a, 54b and an end 55a, 55b.

[0086] Preferably, the free end 54a of the first guide ring section 51a and the free end 54b of the second guide ring section 51b are in contact with each other in the closed state, see for example Fig. 2.

[0087] In the closed state according to Fig. 2 The free ends 54a, 54b and the ends 55a, 55b lie in a plane that lies in the longitudinal axis and is vertically oriented.

[0088] The two guide ring sections 51a, 51b can, as will be described in detail later, be arranged together with the two drive ring sections 31a, 31b in an open position in which the receiving area 15 within the drive ring 30 is accessible perpendicular to the longitudinal axis L, see Fig. 4 and Fig. 5. The two guide ring sections 51a, 51b can also be arranged with the drive ring sections 31a, 31b in a closed position in which the receiving area 15 is closed around the longitudinal axis, see Fig. 1-3.

[0089] In particular the Fig. Figure 7 shows that the guide ring sections 51a, 51b can be connected at the end 55 by means of a joint 57. The joint 57 has a pivot axis X2, whereby the guide ring sections 51a, 51b can be rotated or pivoted about the pivot axis X2 in order to be arranged with the drive ring sections 31a, 31b from the closed state to the open state to form the insertion opening 32 and back.

[0090] Further with reference to the Fig. 6 and Fig. As can be seen from Figure 7, the drive device 1 can have a locking device 70 by which the drive ring 30 can be blocked relative to the guide ring 50.

[0091] The locking device 70 can be installed according to the exemplary embodiment in the Fig. 6 and Fig. 7 comprising an actuating device 72, wherein the actuating device 72 comprises a locking element 74 which holds the drive ring 30 or the respective drive ring section 31a, 31b positively on the guide ring 50 or the respective guide ring sections 51a, 51b.

[0092] The locking element 74 can engage in a recess of the drive ring 30 to block it. This allows the drive ring 30, or the corresponding drive ring section 31a, 31b, to be positively locked to the guide ring 50, or the corresponding guide ring section 51a, 51b, and / or prevents movement of the corresponding drive ring section 31a, 31b relative to the corresponding guide ring section 51a, 51b.

[0093] In the illustrated embodiment, the drive ring 30 can have a recess formed on one end face into which the locking element 74 can engage.

[0094] The recess can be arranged on an annular groove 39 on one of the end faces of the drive ring, preferably radially outwards. In the unactuated state of the locking device 70, the locking element is arranged in the annular groove 39 and allows rotation of the drive ring 30 relative to the guide ring 50. In the actuated state of the locking device 70, the locking element can engage in the recess and blocks rotation of the drive ring 30 relative to the guide ring 50. Furthermore, in the open state of the drive ring 30, the locking element 74 can pull the drive ring section 31a, 31b into the radial groove 56 within the guide ring section 51a, 51b.

[0095] Typically, the drive device 1 has two locking devices 70, which for simplicity are indicated in the figures by reference numerals 70a and 70b. A first locking device 70a is arranged on the first guide ring section 51a, and a second locking device 70b is arranged on the second guide ring section 51a.

[0096] In the open position, the first locking device 70a blocks relative movement between the respective nested first guide ring sections 51a and the first drive ring section 31a, and the second locking device 70b blocks relative movement between the respective nested second guide ring sections 51b and the wider drive ring section 31b. Displacement between the nested parts is thus prevented.

[0097] The drive device 1 can further comprise an actuating device (not shown) by which the guide ring sections 51a, 51b can be rotated about the axis of rotation X2. The actuating device can, for example, include a hydraulic, pneumatic and / or electromechanical actuator by which the guide ring sections 51a, 51b can be rotated about the axis of rotation X2 to open and close the drive ring 30.

[0098] The housing 20 can comprise a housing base part 24, wherein the guide ring sections 51a, 51b can be rotatably supported on the housing base part 24 in the axis of rotation X2.

[0099] The housing base part 24 can include fastening means by which the drive device 1 - as in Fig. 1 is shown - to be permanently arranged on a machine tool 2.

[0100] Furthermore, the drive device 1, as shown in the accompanying figures, includes the drive unit 10.

[0101] The drive device 10 comprises a drive belt 12, which for the sake of simplicity is shown only in Fig. Figure 3 is shown. The drive belt 12 is preferably a toothed belt whose tooth profile corresponds to the tooth profile of the previously described external teeth of the drive ring 30.

[0102] The drive belt 12 can be driven by a drive 18.

[0103] The drive belt 12 engages with the drive ring 30 in an engagement area 16, wherein the engagement area 16 engages the drive ring 30 by approximately 270° in the direction of rotation of the drive ring 30.

[0104] The drive belt 12 engages the drive ring 30 in a U-shaped loop from the side of the drive ring 30 opposite the insertion opening 39, ensuring that the drive belt 12 does not block the insertion opening 32 in the open position.

[0105] The U-shaped loop is formed by several deflection pulleys 14. Starting from the axis of rotation X2, several deflection pulleys 14 can be arranged along the guide ring sections 51a, 51b, with the engagement area 16 being located between the two outermost deflection pulleys 14 along the guide ring sections 51a, 51b. By applying appropriate tension to the drive belt 12, the drive belt 12 can be kept in engagement with the external teeth of the drive ring 30, and high torques can also be transmitted.

[0106] The guide ring 50 can have one or more openings 58 through which drive belt 12 can be guided to engage with the drive ring 30.

[0107] Furthermore, as shown in the accompanying figures, the drive device 1 can have a support unit 80. The support unit 80 is arranged on the housing 20 and is configured to support the workpiece 5 along its longitudinal axis L. This prevents, for example, gravity-induced deflection of the workpiece 5. The support unit 80 is preferably spaced apart along its longitudinal axis from the drive ring 30.

[0108] The support unit 80 can be height-adjusted perpendicular to the longitudinal axis L to accommodate different workpiece diameters. The support unit 80 can also be interchangeable or partially interchangeable to adapt it to different workpieces 5.

[0109] The method for centrally rotating the shaft-like workpiece 5 arranged in the longitudinal axis L with the drive device 1 according to the first embodiment can be described as follows: The drive ring 30 is rotated about the longitudinal axis L until the position is reached in which the free ends 34a, 34b of the drive ring 30 and the free ends 54a, 54b of the guide ring 50 are aligned with each other and / or the axes of rotation X, X2 of the joints 37, 57 are coaxial. The position of the drive ring 30 can be detected by means of sensors.

[0110] The locking device 70 can then be actuated to lock the drive ring 30 in the guide ring 50, or in other words, to lock the first drive ring section 31a in the first guide ring section 51a and the second drive ring section 31b in the second guide ring section 51b.

[0111] Then the drive ring 30 can be brought into the open position by pivoting the two drive ring sections 31a, 31b.

[0112] For this purpose, the (not shown) actuating device can pivot the guide ring sections 51a, 51b about the axis of rotation X2, whereby the drive ring sections 31a, 31b follow the pivoting movement and the insertion opening 32 is formed between the free ends 34a, 34b.

[0113] In the open position, the receiving area is accessible in a direction essentially perpendicular to the longitudinal axis L through the insertion opening 32.

[0114] The workpiece 5 is then inserted into the receiving area 15 through the insertion opening 32 in a direction essentially perpendicular to the longitudinal axis L.

[0115] The drive ring 30 is brought into a closed position by pivoting back the two drive ring sections 31a, 31b, thereby enclosing the receiving area 15.

[0116] For this purpose, the actuating device (not shown) can pivot the guide ring sections 51a, 51b back about the axis of rotation X2, whereby the drive ring sections 31a, 31b follow the pivoting movement and the drive ring 30 or the insertion opening 32 is closed.

[0117] To machine the workpiece 5, the drive ring 30 can be rotated, the rotational movement of the drive ring 30 being transmitted to the workpiece 5 by the at least one driver 40a, 40b. The drive ring 30 can be driven by the drive unit 10.

[0118] Fig. Figures 8 to 10 show a second embodiment of an exemplary drive device 1.

[0119] For the sake of simplicity, only the differences between the two exemplary embodiments will be discussed below.

[0120] The Fig. 8 and Fig. Figure 9 shows the drive device 1 in the closed state, with some components, for example of the drive unit 10 and the housing 20, hidden for illustrative purposes.

[0121] As previously described, the guide ring 50 is formed in multiple parts in the circumferential direction and comprises the two guide ring sections 51a and 51b. In contrast to the first embodiment, the first guide ring section 51a is fixed. For example, the first guide ring section 51a can be formed integrally with the housing base part 24 or be rigidly connected to it.

[0122] The drive ring 30, as previously described, is also multi-part in the circumferential direction and can be driven via the drive belt 12. The drive belt 12 engages with the drive ring 30 in the engagement area 16. The engagement area 16 can laterally encompass the drive ring 30 by approximately 180° in the direction of rotation.

[0123] The drive belt 12 lies laterally against the drive ring 30 in a U-shaped loop, the U-shaped loop being formed by several deflection pulleys 14, which may preferably be arranged inside the housing 20, in particular in the stationary first guide ring section 51a.

[0124] In particular the Fig. 8 can be seen that the drive belt 12 is engaged with the external teeth of the drive ring 30 within the radial groove 56 of the first guide ring section 51a.

[0125] The drive ring 30 can be supported on the guide ring 50 by several bearing means 52, for example designed as rolling bearings, wherein the bearing means 52 support the drive ring 30 radially and / or axially.

[0126] Preferably, bearing surfaces are formed along the longitudinal axis L on both sides of the toothing 33 of the drive ring 30, which interact with the bearing means 52. The bearing surfaces can be, for example, cylindrical or conical surfaces.

[0127] For example, the bearing means 52 can interact with the bearing surfaces designed as conical shell surfaces, whereby the bearing means 52 can realize both an axial and a radial bearing arrangement.

[0128] The Fig. It can also be seen from figures 8 to 10 that the insertion opening 39 between the free ends 34a, 34b of the drive ring sections 31a, 31b or the free ends 54a, 54b of the guide ring sections 51a, 51b can be formed as in the previous embodiment.

[0129] At least one of the at least two drive ring sections 31a, 31b and at least one of the at least two guide ring sections 51a, 51b can be pivoted about the axes of rotation X, X2 of the joints 37, 57 in order to be arranged from the closed state to the open state to form the insertion opening 32 and back.

[0130] The joint 37 of the at least two drive ring sections 31a, 31b has a rotation axis X, wherein the drive ring sections 31a, 31b can be rotated or pivoted about the rotation axis X.

[0131] The joint 57 of the at least two guide ring sections 51a, 51b has a rotation axis X2, wherein the guide ring sections 51a, 51b can be rotated or pivoted about the rotation axis X2. The rotation axes X, X2 are preferably coaxial.

[0132] In the closed state, the drive ring 30 is closed and the free ends 34a, 34b lie against each other.

[0133] In the closed state according to Fig. 8 and Fig. 9. The free ends 54a, 54b and the ends 55a, 55b lie in a common plane with the longitudinal axis L. This plane is rotated about the longitudinal axis L by approximately 10° - 45°, preferably 15° - 30°, and even more preferably by approximately 25°, relative to the vertical.

[0134] To exit the closed state according to the Fig. 8 and Fig. 9 in the open state according to Fig.To achieve 10, preferably - as in the first embodiment - the drive ring 30 should be rotated into a position in which the free ends 34a, 34b and the free ends 54a, 54b are aligned with each other and / or the axes of rotation X, X2 are arranged coaxially.

[0135] Subsequently, the locking device 70 (not shown in this embodiment) can be actuated to lock the drive ring 30 in the guide ring 50, or in other words, to lock the first drive ring section 31a in the first guide ring section 51a and the second drive ring section 31b in the second guide ring section 51b.

[0136] Then the drive ring 30 can be brought into the open position by pivoting the second drive ring section 31b.

[0137] For this purpose, the (not shown) actuating device can pivot the second guide ring section 51b about the axis of rotation X2, whereby the second drive ring section 31b follows the pivoting movement and the insertion opening 32 is formed between the free ends 34a, 34b. As already noted above, the first guide ring section 51a is stationary and is therefore – like the associated drive ring section 31a – not moved or pivoted by the actuating device.

[0138] In the open position, the receiving area 15 is accessible in a direction essentially perpendicular to the longitudinal axis L through the insertion opening 32.

[0139] The workpiece 5 can then be inserted into the receiving area 15 through the insertion opening 32 in a direction essentially perpendicular to the longitudinal axis L. The workpiece 5 can be placed directly onto the driver 40a.

[0140] The drive ring 30 is brought into a closed position by pivoting back the second drive ring section 31b, thereby enclosing the receiving area 15.

[0141] During the return swing, the second driver 40b is positioned on the side of the workpiece opposite the first driver 40a. The second driver can engage the workpiece with a retaining lug 42.

[0142] To move into the closed position, the actuating device can pivot the second guide ring section 51b back about the axis of rotation X2. The second drive ring section 31b follows the pivoting movement and the drive ring 30 or the insertion opening 32 is closed.

[0143] The first drive ring section 31a with the driver 40a remains unchanged in its position during the change between the open and closed states. This prevents any relative movement between the workpiece 5 and the driver 40a of the first drive ring section 31a. Therefore, damage to the workpiece, such as scratches, can be avoided.

[0144] The locking device 70 can be actuated to release the drive ring 30 in the guide ring 50 so that the drive ring 30 can be rotated relative to the guide ring 50 about the longitudinal axis L, for example for machining the workpiece.

[0145] To machine the workpiece 5, the drive ring 30 is rotated about the longitudinal axis L, whereby the rotational movement of the drive ring 30 is transferred to the workpiece 5 by the at least one driver 40a, 40b. Reference symbol list 1 Drive device 2 3 Machine tool tailstock 4 tailstock 5 workpieces 10 Drive unit 12 drive belts 14 Deflection wheel 15 Recording area 16 Intervention area 18 Drive 20 cases 24 Housing base part 30 Carry-on ring 31. Carriage ring section 32 Insertion opening 33 Gear teeth 34 open ending 35 End 37 joints 39 Ring groove 40 drivers 42 Retaining nose 50 guide ring 51 guide ring sections 52 storage devices 54 open ending 55 End 56 Radial groove 57 joint 58 breakthroughs 60 Actuating device 70 Locking device 72 Actuating device 74 Locking element 80 support unit B Width L Longitudinal axis X axis of rotation QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 103 49 432 B3

[0002]

Claims

[1] Drive device (1) for centrally rotating a shaft-like workpiece (5) arranged in a longitudinal axis (L), comprising - a drive unit (10) with a housing (20), and - a drive ring (30) rotatable about a longitudinal axis (L) by the drive device (10), which can surround a receiving area (15) in which the workpiece (5) can be arranged for machining, and - wherein the drive ring (30) comprises at least two drive ring sections (31a, 31b) in a direction of rotation around the longitudinal axis (L), which can be arranged in an open position in which the receiving area (15) is accessible perpendicular to the longitudinal axis (L) and in a closed position in which the receiving area (15) is closed around the longitudinal axis (L), and - wherein the drive ring (30) has at least one driver (40a, 40b) for transmitting the rotation of the drive ring (30) to the workpiece (5). [2] Drive device (1) according to claim 1, characterized by , that in the open position between at least one of the ends (34a, 34b, 35a, 35b) of the at least two drive ring sections (31a, 31b) an insertion opening (32) is formed which enables the workpiece to be inserted perpendicular to the longitudinal axis (L). [3] Drive device (1) according to claim 1, characterized by , that the drive ring (30) has an inner diameter (DI) and that a width (B) of the insertion opening (32) corresponds approximately to the inner diameter (DI). [4] Drive device (1) according to claim 1, characterized by , that the drive ring (30) is rotatably supported on the housing (20). [5] Drive device (1) according to claim 1 or 2, characterized by , that the drive ring (30) comprises a toothing (33) via which the drive ring (30) can be driven by the drive device (10). [6] Drive device (1) according to one of the preceding claims, characterized by , that the drive device (10) includes a drive belt (12). [7] Drive device (1) according to one of the preceding claims, characterized by , that the drive belt (12) engages with the drive ring (30) in an engagement area (16), wherein the engagement area (16) surrounds the drive ring (30) by less than 360°, preferably less than 270°, in the direction of rotation. [8] Drive device (1) according to one of the preceding claims, characterized by , that the drive device (10) includes at least one deflection wheel (14). [9] Drive device (1) according to one of the preceding claims, characterized by , that at least two deflection wheels (14) span the engagement area (16). [10] Drive device (1) according to one of the preceding claims, characterized by, that the housing (20) includes a guide ring (50), and that the drive ring (30) is rotatably mounted in the guide ring (50). [11] Drive device (1) according to one of the preceding claims, characterized by , that the guide ring (50) is multi-part and comprises at least two guide ring sections (51a, 51b). [12] Drive device (1) according to one of the preceding claims, characterized by , that the at least two drive ring sections (31a, 31b) correspond to the at least two guide ring sections (51a, 51b). [13] Drive device (1) according to one of the preceding claims, characterized by , that an actuating device (60) is provided, and that by means of the actuating device (60) at least one of the at least two guide ring sections (51a, 51b) and / or at least one of the at least two drive ring sections (31a, 31b) can be moved into the open position and / or into the closed position. [14] Drive device (1) according to one of the preceding claims, characterized by , that at least one of the at least two guide ring sections (51a ,51b) together with at least one of the at least two drive ring sections (31a, 31b) is pivoted by the actuating device (60) about at least one axis (X), preferably about a common axis (X), in order to change from the open position to the closed position. [15] Drive device (1) according to one of the preceding claims, characterized by , that at least one locking device (70a, 70b) is provided by which a rotation of the drive ring (30) relative to the guide ring (50) can be blocked. [16] Drive device (1) according to one of the preceding claims, characterized by, that the at least one locking device (70a, 70b) in the open position securely holds the respective of the at least two drive ring sections (31a, 31b) on an associated of the at least two guide ring sections (51a, 51b). [17] Drive device (1) according to one of the preceding claims, characterized by , that at least one of the drivers (40a, 40b) is interchangeable. [18] Drive device (1) according to one of the preceding claims, characterized by , that at least two drivers (40a, 40b) are provided and that the at least two drivers (40a, 40b) can grip the workpiece in a fork-like manner. [19] Drive device (1) according to any of the preceding claims, characterized by , that the at least two drive ring sections (31a, 31b) each have at least one drive element (40a, 40b). [20] Drive device (1) according to one of the preceding claims, characterized by, that at least one of the at least two drivers (40a, 40b) is spring-loaded in the direction of rotation. [21] Drive device (1) according to one of the preceding claims, characterized by , that a support unit (80) is provided for supporting the workpiece (5) in the longitudinal axis (L). [22] Drive device (1) according to one of the preceding claims, characterized by , that the support unit (80) is height-adjustable perpendicular to the longitudinal axis (L) to adapt to different diameters of the workpiece (5). [23] Drive device (1) according to one of the preceding claims, characterized by , that the support unit (80) is interchangeable. [24] Machine tool with a drive device (1) according to one of the preceding claims. [25] Method for centrally rotating a shaft-like workpiece (5) arranged in a longitudinal axis (L), in particular for end machining, with a drive device (1), in particular a drive device (1) according to one of the preceding claims, with a driven drive ring (30) which can enclose a receiving area (15) around the longitudinal axis (L) and which has at least one driver (40a, 40b), wherein the drive ring (30) comprises at least two drive ring sections (31a, 31b) in a direction of rotation around the longitudinal axis (L), comprising the following method steps: - Opening the drive ring (30) by moving at least one of the at least two drive ring sections (31a, 31b) into an open position in which the receiving area (15) is accessible perpendicular to the longitudinal axis (L), - Inserting the workpiece into the receiving area (15), - Closing the drive ring (30) by moving at least one of the at least two drive ring sections (31a, 31b) into a closed position in which the receiving area (15) is enclosed, - Driving the drive ring (30) and transferring the rotary motion about the longitudinal axis (L) through the at least one driver (40a, 40b) to the workpiece (5).

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