Spindle drive device for machine tools

p0001Spindle drive device for machine tools

p0002The invention relates to a spindle drive device for machine tools, with a work spindle for holding a workpiece to be machined, a spindle drive motor and a provided between it and the work spindle switchable planetary gear for a spindle drive with different gear ratios, said at least three gear elements, namely a sun gear, a planetary gear carrier with a planetary gear set and a ring gear, planetary gear aufwei¬ send a rotationally fixed to the drive motor connected input drive gear member and a beitsspindel with Ar¬ standing in drive connection Abtriebsgetrie¬ beelement possesses.

p0003Such spindle train is from the Druck¬ thing "SIMODRIVE - AC main spindle drives with AC motors Dreh¬ 1 PH 5, 1 PH 6 and a transistor pulse converter 6 SC 65", edition March 1987 Siemens AG. The spindle drive motor and the planetary gear umfas¬ transmission assembly of this known device is to be located outside of the headstock of the machine tool, the driven gearing element of the planetary gear is provided with a pulley, and the drive connection to the work spindle via a belt. Der.Spindelan¬ drive motor and the planetary gear are in the direction of the motor shaft axis side by side, and the motor shaft drives depending on the position of a comprehensive motor shaft and a sliding sleeve having clutch either the sun or the ring gear on - the planet carrier (also called web) is connected to the pulley verbun¬ the. In the above description is still sen hingewie¬ that the drive power instead can be transmitted via belt and a sprocket or a flexible coupling at the transmission output. In this known device, the planetary gear performs the transmission output at a Ver¬ backlash (gearless) 30-45 minutes of arc, with a special design of the planetary gear 25 arcmin. For play-free holding the transmission output shaft and da¬ with the machine tool work spindle of the installation of an electromagnetic holding brake is recommended.

p0004On modern working spindle drives especially for Drehma¬ machines, especially if these are intended for Komplettbearbei¬ processing of turned parts, high Anforderun¬ made gen: A vibration-free operation possible for Er¬ sighting highest surface quality, even at high speeds, connected to the best possible Rundlaufei- properties; . Pay a high driving torque at low Dreh¬ to perform heavy machining can, even at an interrupted section as for example for the polygonal turning is typical; an exact rotational angle excessive positioning of the main spindle, eg for milling and drilling with live tooling. Operation of Arbeits¬ spindle as a spindle with a so-called rotary axis (C-Ach¬ se), ie with a controlled angle of rotation feed for Frä¬ sen curves of all kinds, die chaser (especially with threads of high pitch), for hobbing of toothed wheels etc.

p0005Known spindle drive devices with switchable toothed wheel gears and / or belt drives result in especially high speeds no perfect rotation picture, ie not the ge wished high surface quality. This is on Eingriffs¬ violations of the gears and / or vibrations of the belt drive due. Also acting on the work spindle transverse forces, caused by the meshing and / or the belt tension, and such transverse forces have an unavoidable deflection of the work spindle result, by the Pro¬ impaired duktionsgenauigkeit. A has a toothed play traceable backlash of a drive input located between motor and the work spindle gear transmission for heavy machining work and interrupted cutting a negative influence on the tool blades and their life. An exact rotation angularly positioning of the main spindle, the use of a locking disc erfor¬ sary, which limits the possible angle of rotation positions on the position and number of clicks; positioning the Ar¬ beitsspindel in any rotational angular positions requires a holding brake in the drive unit and is only possible if the latter is free of play, z. B. in the case of getriebelo¬ sen drive unit which is connected beitsspindel via a belt drive with the Ar¬. Finally Ver¬ use of the work spindle in any case requires a so-called rotary axis (C-axis) a play-free and rigid spindle drive; if only small machining forces occur, a locking bar is men-direct drive sufficient, otherwise separate, highly stocky and play-free auxiliary drives are used, wel¬ che in a spur or worm are pivoted on the work spindle. However, such auxiliary drives only allow a maximum of 50 - 60 U / min, for example for thread chasing or gear cutting is often not enough, also such auxiliary drives are very complex and expensive.. Some of these requirements is met by cops called Motor¬; in these, the rotor or rotor of the spindle drive motor forming three-phase motor directly part of the work spindle. Quiet running, zero backlash and stiffness of such a drive are excellent, but they have because of the limited installation space available insufficient driving torque, so that heavy machining and use of Arbeits¬ spindle as so-called rotary axis are not possible.

p0006A solution to the problem, the work spindle called as so-to operate rotary axis, is the two-stage transmission according to DE-PS 39 30 334 of the applicant group; In this known transmission can be to play free Make the slow speed, the one bearing the transmission input shaft in the radial direction adjust. However, then the toothed is no longer intervened correctly, and because of this transmission, the output shaft is formed by the work spindle, driven by Spin¬ dela drive motor via a belt drive, it has the above-mentioned disadvantages of belt drive and gear drives.

p0007The invention was based on the object, a Spindelan¬ drive device for the work spindle of Werkzeugmaschi¬ NEN introduction which the smooth running garan¬ Animal T and allows, even at high speeds produce workpieces with highest surface quality.

p0008Starting from a spindle drive device of the type mentioned, this object can be solved according to the invention, the drive motor a koaxia¬ to work spindle len, the latter comprising, hollow shaft-like rotor having and the planetary gears to the work spindle axis are arranged ange¬ and that the rotor rotatably to the Eintriebsge¬ gear element of the planetary gear and its Abtriebsge¬ gear element rotatably connected to the work spindle is connected. Such construction includes in particular the following advantages: As with the so-called motor spindles acting transverse forces are avoided in the work spindle as a belt drive is not available and the planet gears are arranged around the main spindle axis; running properties best Rund¬ are therefore guaranteed. Moreover elimi¬ the spindle drive device according to the invention defined the vibrations that occur in belt drives, as a belt drive is not present. Also can be a switchable Planeten¬ gear readily designed so that drive motor in high gear Eintriebs- and output gear element and thus Spindelan¬ and work spindle rotatably connected together, so that it allows the invention Spindelantriebsein¬ direction, to achieve the benefits of so-called motor spindles, namely quiet running, zero backlash and high stiffness of the drive and thus the production of turned parts of the highest surface quality at high speeds. Finally, esp in low gear of Planetengetrie¬ high drive torques can be achieved on the work spindle and thus perform heavy machining.

p0009Particularly good concentricity properties arise when the planetary gears are arranged around the work spindle axis from each other at equal angular intervals.

p0010As already indicated above, a preferred embodiment of the invention is distinguished Spindelan¬ drive device is characterized in that the quick transition of Pia designated gearbox whose planet gears are held gear carrier can not rotate relative to the planet and the Eintriebsgetrie¬ beelement rotationally fixed to the output gear element is connected. Then place in high gear of the planetary gear, a gear passing not occur, so that the problems associated with a backlash and meshing jolts of gears disadvantages can not occur. In addition, the transmission Planetenge¬ can produce with such a small backlash that there is almost no play in slow transition without high speeds would lead to severe wear in high gear.

p0011While at the outset known spindle drive device with planetary gear for changing gear, a clutch lying outside the actual planetary gear is used with sliding sleeve, a preferred embodiment of the Spindelan¬ invention is distinguished drive device by a particularly simple and kompak¬ th assembly of; in this preferred embodiment is for shifting the planetary gear whose lying between Eintriebs¬ and output gear element mid Getriebeele¬ ment towards the spindle axis between a first, the slow gear, and a second, the rapid transition zuge¬ arranged switching position slidably and non-rotatably in its first switch position maintained and in its second switching position freely rotatable, it connects drive gear element rotatably together Eintriebs- and Ab¬. ating The un- rotatable holding the central gear element into its first switching position and the rotational connection of Ein¬ and output gear element through the middle Ge transmission element in its second switch position can be axially extending pins and corresponding Openings, annular teeth with it in the axial direction Rich¬ extending teeth or serve like so that a simple shift of the central gear element sufficient to bring the coupling elements engaged or disengaged. A relative of the planetary gear external coupling can therefore be dispensed with. Particularly simple is such a construction, when the average Getriebeele¬ ment in its first switching position in rotation with a Ge transmission housing is connected, though of course you can also contact another stationary member in the place of the transmission housing.

p0012As already mentioned, is used in the initially explained be¬ knew spindle train with planetary gear an additional electromagnetic brake to hold the transmission output shaft and thus of the work spindle. Also associated in this respect enables Spindelan¬ inventive drive device a substantial simplification in that it is designed so that the central gear element is pushed in a third switching position in which it an¬ both to the transmission housing, and with at least one of the two whose gear elements rotatably is what can be achieved wie¬ in turn preferably by means of annular teeth with axially extending teeth. An additional holding brake can be omitted so, and the spindle can be Arbeits¬ blockie¬ reindeer in as many angular positions as the gear housing or the middle Getriebeele¬ element has retaining teeth.

p0013For, when it in which the latter ent speaking switching state of the planetary gear rotates to hold the middle gear member in its jewei¬ time shift position, of outside to have initiated any holding forces in the transmission, for example, it is advisable to hold the central gear element provided on the central gear element and at least one of the other gear elements latching means least in this position, eg. a recess and a correspondingly designed, sprung locking element.

p0014To the average transmission element departures controlled between its various switching positions and heart uschi precisely, it would be conceivable in principle to incorporate a portion extending in the axial direction pressure cylinder in the planetary gear, for example -. With the working spindle rotating pressure medium cylinders are for example in the form of. clamping cylinders for actuating workpiece clamping devices of the work spindle known. Much easier however is an embodiment having a ver¬ towards the spindle axis between min¬ least a first and a second position on the transmission housing slidably held slide coupled in the direction of the spindle axis via a first driver with the central gear element. For such slides can then be operating means, such as pressure medium cylinders, stationary to the gearbox housing.

p0015In a particularly advantageous embodiment of the inventive spindle drive device means are hen vorgese¬ to make the planetary gear in low gear absolutely spiel¬ free, so that the Spindelantriebs¬ invention then means not only the operation of the work spindle as a so-called rotary axis allows, namely provisions in both Drehrich¬ but also heavy machining can be performed with high torque without a unterbro¬ chener section of an impairment of the cutting Tools used and thus lead their life. The invention makes this use of the fact that a planetary transmission suited for quasi-lossless superposition of two speeds or turning and / or braking torques is, namely because of its three listed above Getrie¬ beelementen two as input drive gear elements and the third used as the output gear element can be. Jump to clearing the Spindelantriebsein¬ inventive device in slow gear has at a disiloxane ferred embodiment, the planetary gear to at least one of its three gear elements equivalent fourth gear element, and there is a locking device provided in the low gear of the planetary gear to eliminate any match of the latter, two mutually equivalent gear elements to rotate against each other. Two Planeten¬ wheelsets, on the two mutually equivalent Getriebe¬ then elements act so lead to strain and thus the game freeing of the planetary gear. According to the direction of the required on the work spindle Drehmo¬ management you will expediently select the rotation of such a fourth gear element by twisting and size of the rotation so that the torque transmission from An¬ drive motor to the working spindle form fit occurs and le¬ diglich a lead or hasty work spindle when caused by the workpiece machining, zeit¬ Lich not constant braking torque is prevented. You could stress the transmission but also selected so high that it can also be by the maximum torque of Antriebsmo¬ sector not overcome, but this greater friction and greater wear in the transmission would result. If such an embodiment of Spin¬ invention dela drive device, which can be freely in low gear spiel¬, provided with a slide described above, it is recommended that construction Stalten to ge so that the slide in its first switch position in the circumferential direction adjustable and coupled via a second carrier with the fourth gear element (under Umfangs¬ direction the two work spindle rotation are ver¬ stood). One and the same element, namely the slide, can then be used to the planetary gear to not only turn, but also to make it in low gear and backlash. Does the device then a Stell¬ device for adjusting of the in its first switching position slide from a central position out either in one or the other circumferential direction, the planetary gear can be easily in Abhän¬ dependence on the direction of on the make work spindle geforder¬ th torque backlash without a high Verspan¬ tion is required with the above-mentioned drawbacks.

p0016The adjusting device or adjusting devices for Verstel¬ len of the slide in the axial direction and / or has in Umfangs¬ direction and expediently have free two Stell¬ elements which engage opposing portions of the slide to the latter controlled and spiel¬ bring in the various switching positions and being able to keep it there.

p0017In a planetary gear one has the choice between three different transmission inputs, since both the sun, and the planet carrier and / or the Hohl¬ wheel (often called ring gear) as input drive gear element can be used. The Spindelantriebs¬ device according to the invention can thus be designed so that in low gear resting (often also called web) or the ring gear, either the sun gear or the planet. As still erge¬ ben is the following description of the illustrated in the accompanying Zeich¬ planning various embodiments, performs a structure in which the ring resting in low gear, tive to a simpler construction of the device according to the invention than the other two Alterna¬. In preferred embodiments, the device Maessen erfindungsge¬ therefore the ring gear forms the average Ge transmission element. The simplification of the structure also serves the measure, turn the sun as input drive gear element to ver¬.

p0018Embodiments in which the ring gear forms the middle Getrie¬ beelement, are expediently designed so that the ring gear in its second switching position no touch contact tion with the transmission housing has - in its first switching position it is advantageously held fest¬ the gearbox - so as to minimize friction losses in the high gear.

p0019Set in an inventive device in which the ring gear forms the central gear element, provide for the possibility of being able to make the planetary gear in low gear backlash, so a Ausfüh¬ recommend bodiment in which the adjusting device a second, about the spindle axis rotatable ring gear , with which meshes a zwei¬ ter set of planet gears. This second ring gear er¬ allows then a simple external intervention in the Pla¬ designated gear to make by a relatively slight rotation of the second ring gear, the planetary gear backlash. If a second set of planet gears available to make transmission in low gear, the Ge backlash may, it is mainly to achieve the best possible Rundlaufgenauig¬ speed in high gear advantageous if also the second planetary gears at equal angular distances from each other around the work spindle axis around are arranged.

p0020For embodiments with a second ring gear, and a second set of planetary gears, it is recommended the weite¬ reindeer, the two ring gears to make common axis toward the Spindel¬ displaced and Stalten to ge the structure so that in the second switching position the second plane ¬ tenräder and the second ring gear are disengaged, so that the second ring gear in the gear does not have to rotate fast.

p0021Since the use of a Spindelantriebs¬ invention means either a belt drive is required, even a swing-drive system for the use of Arbeits¬ spindle as so-called rotary axis, the inventive spindle drive device is particularly suitable for Werkzeug¬ machine in which one or more work spindles not stationary but displaced are. This is especially true for lathes with two opposite coaxial spindles, of which at least one is movable in Spindelachs¬ direction, so that after a further feature of the invention in such lathes finds a erfindungsge¬ Permitted spindle drive means for driving the ver¬ sliding work spindle using ,

p0022Further features, advantages and details of the invention will become apparent from er¬ the appended claims and / or the following description and the appended zeichneri- see presentation of some particularly advantageous Ausfüh¬ ments of the spindle drive device according to the invention; in the drawing:

p0023FIG. 1 is an axial section through a machine headstock a Drehma- including work spindle and integrated, inventive concept mäßer spindle drive means, said Figure 1 illustrates a first embodiment of the inventive device.

p0024Fig. 2 is a section of Figure 1, which drives the Planetenge¬ in the same switching position, namely in langsa¬ men gear, as shown in Figs 1, but on a larger scale. FIG.

p0025.. Figure 3 shows the same view as in Figure 2, but with the planetary gear sets in the one switching state darge was where it sits be¬ no transmission function, ie in high gear;

p0026Fig. 4 is the same view as in Figures 2 and 3, but with the stand in the one planetary gear Schaltzu¬ has been illustrated in which the planetary gear and hence the work spindle is blocked;

p00275 shows a section through the planetary gear along the line 5-5 in Fig. 2.

p0028Figure 6 is a plan view of a slider for switching of the planetary gear together with adjusting devices for the actuation of the slide, seen in the direction of arrow "A" of Figure 2 (first switching position of the rail slat Bers - low speed gear of the planetary gear)..; Fig. 7 is the same view as in Figure 6, but wherein the slide occupies its second switching position (faster gear of the planetary gear).

p0029Fig. 8 is a similar to Fig. 2 a representation zwei¬ th advantageous embodiment of the inventive spindle drive device, and

p0030Fig. 9 is a similar to Fig. 2 view of a third advantageous embodiment of the spindle drive mechanism according to the invention.

p0031Fig. 1 shows a headstock 10 in which a spindle 12 Arbeits¬ is mounted rotatably about a spindle axis 12a. A front, for mounting a workpiece clamping device vorgese¬ hener field of work spindle was designated 12b. To the rear of the headstock 10 transitions into or forms a gear housing 14, in which a below Illustrated Plane¬ housed gear units. In addition, the Spindelka¬ 10 assumes first a spindle drive motor 16 which is which Erfin manure according formed as so-called hollow shaft motor and consists of a stator 18 and a rotor 20, the latter being arranged concentrically to the spindle axis 12a and rotating about said axis with the engine running. It is fixed on a hollow shaft 22 which in turn is mounted concentrically with the working spindle 12, and on this rotatable; This is the purpose, inter alia a front bearing 24, wäh¬ rend a front bearing 26 to the bearings of the front Be¬ Empire of the work spindle 12 in the headstock 10 serves.

p0032According to the invention, the rear portion of the hollow shaft 22 a sun gear 28 listed as 12a concentrically to the spindle axis formed built planetary gear, which has a designated wheels of Pla¬ first planetary gear set 30 is formed. The latter in particular has three identically formed Plane¬ tenräder which stands according to the invention in the same Drehwinkelab- are spaced about the spindle axis 12a around. According to a further feature of the invention, the Son¬ gear member 28 and thus the rear portion of the hollow shaft 22 through the planetary gears 30 is centered.

p0033The further construction of the planetary gear will now be described with reference to FIG. 2, as these, the planetary gear in a larger scale shows, as Figs. 1.

p0034With the work spindle 12 reaction to this unver¬ slidable planet 32 ​​is connected dreh¬ determined by a key 34th To whom a Ach¬ is se 36 is fixed for each planet gear 30 on which the planet wheel concerned is rotatably supported by a needle bearing 38th The axes 36 die¬ but NEN also storing a respective Nebenplaneten- rads 30a which gear member as well as the planet gears 30 with the Son¬ 28 mesh and each of which is a ball bearing 40 zugeord¬ net. The purpose of these side planetary gears 30a will be explained further below. Finally, the gear units Plane¬ still has a ring gear 42 which according to the invention designed as a circular cylindrical ring and in the transmission housing 14 to be longitudinally displaceable, that is arranged in the direction of the spindle axis 12a slidably. According to the invention, the ring gear 42 in the axial direction one behind the other and spaced apart two circular cylindrical gears with axially extending teeth, namely a Laufver¬ toothing 42b 42a and a retaining tooth, which erfindungsge¬ according the running gear 42a arranged in the axial direction so and its length ^"is dimensioned so that the planet gears 42a are 30 in each switching position of the movable ring gear 42 engaged with the running gear. After a wei¬ direct feature of the invention, the gearbox housing 14 is provided with a retaining tooth 14b which is formed by a kreis¬ cylindrical ring extending in the axial direction of teeth and the same number of teeth has as the holding teeth 42b of the ring gear 42. In the illustrated embodiment the retaining teeth 14b formed at a fixed gehäuse¬ housing wheel 44 which lid on a gehäuse¬ 46 is fixed, which in turn is an integral part of the gear housing fourteenth Finally, the Plane¬ gear carrier 32 is opening at its outer periphery with a Halteverzah¬ 32b, which is formed by a circular cylindrical ring extending axially teeth, the number of teeth in turn is the same as that of the retaining teeth 42b of the ring gear 42. Since LaufVerzah¬ the opening 42a and the holding teeth 42b of the ring gear 42 as well as the retaining teeth 14b of the Gehäuserads 44 and the Halte¬ teeth 32b of the planetary carrier 32 are arranged concentrically to the spindle axis 12a, the ring gear 42 can reciprocate in the axial direction and are hergeschoben.

p0035According to 14 centering means are provided on the ring gear 42 and the transmission housing to the ring gear 42 shown in its in Figure 2 operating position with respect to the Spindelach¬ se to center. 12a; this centering consist of a conical surface 42c on FIG. 2 left end of the ring gear 42 and a corresponding conical surface 14c on Getriebegehäu¬ se 14 or the housing cover 46. For the side planet gears 30a concentrically spindle axis to Spin¬ 12a arranged Nebenhohlrad 50 is provided with its running gear 50a the side planet gears can mesh 30a and through the centering 14c, 42c entspre¬ sponding centering the ring gear 42 in a se to Spindelach¬ 12a concentric position is maintained. According to the invention allows the Nebenhohlrad 50 back and forth together with the ring gear 42 in the axial direction, and its Laufverzah¬ opening 50a corresponds in terms of its diameter, its number of teeth and the alignment of their teeth the Laufverzah¬ opening 42a of the ring gear 42. According to the invention can be the Nebenhohlrad 50 but against the ring gear 42 rotate, and indeed about the spindle axis 12, to make the planetary gear backlash.

p0036For the displacement of the ring gear 42 and the Nebenhohlrads 50 and for the rotation of the latter relative to the ring gear 42, two identical switching devices are provided, one of which is now a reference to the Figures 2 and 5 - to 7 explained.

p0037To the transmission housing 14, a frame 52 is attached, which has a window 54 in the form of an opening, in which is arranged a slider 56 and is guided parallel to the spindle axis 12a displaceably. Figures 2 and 6 show a first switching position of the slide 56, Figures 3 and 7, a second switching position of this slide. Thanks to two zueinan¬ of and to the spindle axis 12a parallel guide surfaces 54 of the window 54 and two opposed Vor¬ projections 56a of the slider 56 can be of one hand parallel to the spindle axis 12a shown by the 6 shown in Fig. First switching position in which in Fig. 7 second Move switch position and the other hand to a voltage level perpendicular to Zeich¬ of Fig. 6 runs in the first switching position shown in FIG. 6 pivot axis 56 verschwen¬ ken. Because of this pivotability has the window 54 has a tapered pane 54b, and the slider 58 Zen¬ trier oblique 56b to ensure that, during displacement of the slide 56 from its in Fig. 6 the first shift position to its shown in Fig. 7 second Schaltstel¬ treatment the slider centered so that its longitudinal central axis parallel to the spindle axis 56c Spin¬ in the second switching position 12a extends.

p0038The displacement of the slide 56 parallel to se Spindelach¬ 12a serve two double acting hydraulic cylinders 60a and 60b, which according to the invention engage opposite points of the slider 56 and so keep this clearance between them. The pivoting of the slide 56 about the pivot axis 58 when the slider is 6 switching position shown in its first, in Fig., Serve hin¬ against two hydraulic cylinders 62a and 62b centered by springs pistons at two diametrically gegen¬ opposite points attack of the slide and so keep this clearance between them. Since according to the invention extend the longitudinal sides parallel 56d of the slider 56 to each other, the slider can be depressurized hydraulic cylinders 62a and 62b move parallel to the spindle axis 12, because then the pistons of these hydraulic cylinders are held by the centering in a central position.

p0039The slide 56 is provided with an inventively concentrically to the pivot axis 58 extending first drive pin 64 and at a distance from this with a second tappet pin 66 provided; the first drive pin 64 engages in a circumferential groove 68 of the ring gear 42, the second Mitnehmer¬ pin 66 in a 50th at denjeni¬ gen of the pin 66 fitted hole 70 of Nebenhohlrads regard to its diameter In this way, by means of hydraulic cylinders 60a, 60b are rotated 62a and 62b, the ring gear 42 and the Nebenhohlrad 50 is displaced parallel to the spindle axis 12a and the Nebenhohl¬ wheel 50 is limited around the spindle axis 12a (the latter in both directions from the center position shown in figures 6 and 7).

p0040In the following the function of the first embodiment shown in the drawings will now be explained in more detail.

p0041In Figures 1, 2 and 6, the invention is Spindelan¬ drive device shown gear unit, where this one transmission function aus¬ exerts and the spindle drive motor 16, the main spindle 12 drives in low gear in the one switching state of Planetenge¬. In this switching state, the ring gear 42 by the retaining toothing 14b of the Getriebegehäu¬ SES 14 and the retaining teeth is prevented 42b of the ring gear 42 from rotating, the planetary gears 30 and the Nebenplanetenrä¬ 30a are driven by the sun gear 28, and then roll in the running gear 42a of the ring gear 42 and the toothing 50a of the running by the second drive pin 66 from rotating from hindered Nebenhohlrads 50 and consequently the planet carrier 32 rotates and thus drives the Ar¬ beitsspindel 12 at. It may be established by the Hydraulik¬ cylinders 62a and 62b, the inventively pressed axially against the ring gear 42 Nebenhohlrad 50 against the ring gear 42 rotate so that the planetary gear in low gear without play. If the gear ratio . Between ring gear 42 and sun gear 28, for example n: 1, the result is a translation between the spindle drive motor 16 and the work spindle 12 of

p0042i = n + 1st

p0043In practice, this is preferably Zähnezahlver- ratio selected such that a ratio i of about 3 results. In the power transmission is advantageous in that three planet gears of each planet gear has to transmit only 1/3 of the power. In addition, is, as in planetary gear units are known which Wälzdrehzahl the planet gears only a fraction of n: (n + 1) of that value which wheel from the speed of the sun 28 and the gear ratio of Sonnen¬ 28 and planetary gear 30 results, so that the to be transmitted through the shifting of the planetary gears power entspre¬ is accordingly lower. So when i = 3 the teeth by Abwälzleistung together only 2/3 of the engine power must über¬ wear because 1/3 of the engine power is transmitted by the motion overlay.

p0044Furthermore, it should be noted that only one strain of the Planetengetrie¬ will bes caused by twisting of the Nebenhohlrads 50, the rotor 20 and the work spindle 12 er¬ go by no twist and can be rotated freely.

p0045By moving the slider 56 by means of the Hydraulik¬ cylinders 60a and 60b in the direction of the spindle axis 12a in the second switching position shown in Figures 3 and 7, the spindle drive mechanism according to the invention in the high gear is switched in the kei¬ the planetary gear ne transmission function has but rather a speed establishes equality of rotor 20 and work spindle 12th In this second switching position, the retaining teeth engage 42b of the ring gear 42 in the retaining teeth 32b of the planetary carrier 32 a, but not in the retaining teeth 14b of the gear housing 14. Since the drive gear 50a of the Nebenhohl¬ wheel 50 is released from the secondary planet gears 30a, roll, neither the planetary gears 30, nor the Nebenplanetenrä¬ of 30a in the running gear 42a of the ring gear 42 from which in this position has no more contact with gehäusefe¬ most parts. The speed transmission is now 1: 1, as the gear elements of the planetary gear block each other. Since a rolling of gears in this switched position does not take place, an optimal running result quality for fine turning operations.

p0046To have initiated in this second switching position of the ring 42 no holding forces from the outside in the planetary gear, this is held in its axial position by a plurality of locking devices, which each consist of a gefeder¬ th latch pin 70a in the planet 32 ​​and a entspre¬ relevant notch 70b consist gear 42nd

p0047In FIG. 4, a third switching state of the planetary gear is shown, in which the ring gear 42 and the spool 56 to take the third switching positions, which are between the first and zwei¬ ten switch positions of these two elements. In this third switching state, the planetary gear and thus the work spindle 12 is blocked. This is achieved in that the retaining teeth 42b of the ring gear 42 both in the Halte¬ teeth 14b of the gear housing 14 and in the Halte¬ teeth 32b of the planet gear 32 engages. In this switching position can, for. Example, when turned off Werk¬ a power tool held by the main spindle 12 workpiece chuck mounted or dismounted. The number of rotational angular positions in which the Arbeitsspin¬ del can block 12 corresponds to the number of teeth of Hohl¬ rads 42; has this z. B. 144 teeth, the Arbeitsspin¬ del may be blocked in 144 angular positions whose Win¬ kelabstand each 2.5 °. Bring the spindle drive motor 16 then a static torque on the spindle drive device according to the invention is clamped without play in this switching state. This status can therefore z. B. also be used to make extremely heavy Fräs¬ machining, z. B. flat surfaces milling large Vier¬. The invention brings it over known machine tool the advantage that the Spindelan¬ drive motor need not be operated in position control, and the positioning of the main spindle is also extremely stiff.

p0048The centering of the slide 56 in its in Fig. 7 darge presented second switching position brings with it the advantage that can be accurately pushed into the teeth of the secondary planetary gears 30a with a stationary spindle drive motor 16 the running toothing 50a of Nebenhohlrads 50 when the rail slat ber 56 is shifted from its illustrated in Fig. 7 second Schaltstel¬ ment out to left.

p0049The switching of the planetary gear takes place at a standstill, wherein the work spindle 12 must be previously brought into a rotational angular position in which the teeth of the intermeshing gears to be shifted are mutually offset by half a treatment Zahntei¬. In a modification of the first embodiment according to the Figu¬ ren 1-7, the planet could be 32 provided with additional axes for the side planet gears 30a, the storage of the planet gears 30 and of the Nebenplanetenrä¬ to broaden 30a.

p0050In addition to fulfilling all An¬ listed above demands on a modern spindle drive device, the invention brings the advantage that the Spindelantriebs¬ device is extremely compact; the work spindle undergoes only a minor extension, but which is more than offset by the lack of a pulley, a catch or brake disc or at the end of Arbeits¬ spindle provided retractable auxiliary drive for the operation of the work spindle as a so-called rotary axis.

p0051The small space requirement of Spindelan¬ drive device according to the invention makes this particularly true suitable for so-called counter-spindle machines in which the acquisition of a machined in a first working spindle workpiece one of the first working spindle opposite and er¬ first work spindle is advanced coaxial counter work spindle toward the workpiece, this to take over and then drive back to its original position. At such a sub-spindle side mounted gear units, motors and the like would be more disturbing and beyond hardly shield against chips.

p0052The illustrated in Fig. 8 second preferred embodiment will be described below only insofar as it differs from the first embodiment and is required than for the understanding of the invention. In addition, were in Figure 8 for parts corresponding in function to parts of the first embodiment, the same reference numerals as in FIGS. 1 - 7 were used, but with the addition of a prime.

p0053The Fig. 8 shows the planetary gear in low gear, ie. In a switching state in which the planetary gear performs a transmission function A sun gear 28 'meshes wie¬ the planet gears 30' and side planet gears 30a ', wel¬ che of a planet 32' or be a Nebenplaneten- gear carrier 32a worn '. While are provided so in the first embodiment, two ring gears, namely the internal gear 42 and the Nebenhohlrad 50, 8 having the second Aus¬ guide according to FIG. Two planet carrier 32 'and 32a', as in this second embodiment, the planetary gear by rotating the Nebenplanetenradträgers 32a 'clearance can be made, as will be shown below. In the switching state shown in Fig. 8, the Pla¬ gear carrier 32 'by means of its retention tooth 32b', and a retaining toothing 14b 'of a transmission housing 14' prevented from hen at Dre¬. The planet in 32 'rotatably mounted Nebenplanetenradträger 32a "has a gear 50b¹Which 'engages in a toothing 50a' of the spindle axis 12a 'limited rotatable adjusting ring 50th A Hohl¬ wheel 42 'is finally fixed to a work spindle 12'.

p0054In the illustrated in Fig. 8 switching state, the slow gear, drives the sun 28 ', the planet gears 30' and the secondary planet gears 30a 'to, the planet carrier 32' is the retaining toothing 14b¹ detained, the Nebenplane¬ gear carrier 32a 'by the collar 50' and in this engaging driving pin 66 'and the latter a supporting slide 56', and the planetary gears 30 'and the side planet gears 30a' drive directly the ring 42 'and thus the work spindle 12' on. With the help of the rail slat bers 56 'can be of the adjusting ring 50' and thus the Nebenpla¬ gear carrier 32a 'to the spindle axis 12 a' twist and thus make the planetary gear backlash.

p0055By moving the gear rack 32 'and the secondary planet gear 32a' by means of the slide 56 'and one supported by this driver pin 64' shown in FIG. 8 to the left, the holding teeth 32b 'and the teeth 50b' free, so that the planet carrier 32 'and the gear carrier 32a Nebenpla¬' can rotate; simultaneously a gear 32c 'of the planet 32' in the opening 42a is LaufVerzah¬ 'of the ring gear 42' is inserted and so the Planeten¬ gear carrier 32 'in rotation with the ring gear 42' and thus to the working spindle 12 '.

p0056. Understanding the 8 is still sen to following hingewie¬. When holding teeth 14b 'of the transmission housing 14' is not it is a continuous annular gear, son¬ countries rather eg two in each case over a circumferential angle of z. B. 30 ° extending toothed segments which are carried by ent speaking segments 90 'of the gear housing 14' and engage in corresponding recesses of the positioning ring 50 '. In addition, the segments are in Fig. 8 represented 90 'offset by 90 °.

p0057While in the above two Ausführungs¬ the sun gear of the planetary gear shapes its forms Eintriebs¬ transmission element and either the driven gear element formed by the planet carrier or from the ring gear, er¬ follows in the third, in Fig. 9 embodiment illustrated form of the input drive via the ring gear and the output drive via the planet carrier. While the two above be¬ described embodiments for the game clearing the Plane¬ tengetriebes either the ring gear or the planet has doubled, the third embodiment shown in FIG. 9 has two sun gears to make the planetary gear in low gear backlash can. . Also, the third embodiment according to Figure 9 will be described in the following only to the extent the wer¬ as they Ren 1 of the first embodiment according to the Figu¬ - 7 differs, and for parts of this third embodiment, which in its function parts of the first embodiment correspond, were the same reference numerals, but un¬ ter addition of two strokes used.

p0058The Fig. 9, which in the switching state corresponding to the slow response shows the planetary gear, in turn, can be a ring gear 42 'and a planet gear 32 "recognize, the ring gear 42' with one of a rotor 20" driven hollow shaft 22 'and the planet carrier 32 is "beitsspindel 12 with a Ar¬" firmly connected. The Planetenradträ¬ eng 32 "carries two sets of planet gears, namely Plane¬ tenräder 30" and side planet gears 30a ". On the Arbeits¬ spindle 12 "are two arranged rotatably and slidably in axial direction to this concentric sun gears, näm¬ Lich a sun gear 28" and this confirmed lead Nebensonnen¬ wheel 28a ", in which in Fig. Switching state illustrated 9, the planet wheels 30 "with the running gear 128" of Sonnen¬ rads 28 "and side planet gears 30a" with the Laufverzah¬ opening 128a "of Nebensonnenrads 28a" comb and the sun gear 28 'by a on a housing 14 "fixed and in a hole of the sun 28 "engaging retaining pin 14b" is prevented from rotating. A slide 56 "carries a first drive pin 64", which "nenrads 28 of Son¬" engages in a circumferential groove 68, and a second Mitnehmer¬ pin 66 ", which in a hole 70" of Nebensonnenrads 28a "is engaged.

p0059In the FIG. Switching state shown 9 of the Planetenge¬ drive (speed gear) drives the rotor 20 'accordingly via the ring gear 42', the planet gears 30 'and the Planetenrad¬ carrier 32', the working spindle 12 ", because the sun gear 28" is prevented from rotating. In this case, the planetary gear can be done without clearance by the Nebensonnenrad 28a "by means of the slide 56" opposite the sun gear 28 'is rotated slightly, resulting in a distortion of the planetary gear the result since both the planet gears 30 "as well as with the Nebensonnenrad 28a "meshing side planet gears 30a" with the running gear 42a 'of the ring gear 42 "mesh.

p0060If using the lock switch 56 "the sun 28" and the Nebensonnenrad 28a "in FIG. 9 so far verscho¬ ben right, that the retaining pin 14b" the sun 28 "releases and its teeth 128" in the running gear 42a 'of the ring ¬ rads 42 "occurs as well as the side planet gears 30a" released from the running gear 128a "of Nebensonnenrads 28a", the planet carrier 32 'at the speed of Ro¬ sector 20 "is driven, since the sun gear 28" opposite the ring gear 42 "is no longer can rotate and consequently the planet 32 ​​"rotate at the same speed as the ring gear has 42". A blocking of the planetary gear and hence the Arbeits¬ spindle is in the embodiments according to Figures 8 and 9 in an analogous manner as in the first embodiment, also possible.

p0061As can be seen from the attached drawings of the three above-described advantageous embodiments of the spindle drive device according to the invention, the switchable gear element of the planetary gear is vorteil¬ way legally operated not only at a single location, son¬ countries several, each particular diametrically gegenüber¬ lying positions, which is why in the illustrated embodiments also two slides 56 and 56 'respectively are "see 56 vorge.

p0062Furthermore, all embodiments shown er¬ accordance with the invention on two planetary gear sets, wherein the two planetary gear sets relative to each other around the transmission axis ge slightly rotated and / or the planet gears of one set (assuming a standstill of the planet gears of the other set) slightly about their respective axis are dreh¬ bar to the planetary gear when it befunktion a Getrie¬ met to (ie, in particular in low gear) make any play. To accomplish this, according to the invention at least one of the three transmission elements sun, planet and ring gear doubled to rela¬ tively to other equivalent transmission element to Getrie¬ beachse around to clamp by slightly twisting a transmission element, the transmission bit and characterized a game to eliminate. It is at the ver¬ double gear element not one of those Getriebe¬ elements that make up the gearbox input and the transmission output or associated with these non-rotatably.