Gleason-Hurth Stroj Za Honanje Zobnikov nakup rabljenega (86.418)

Stanje: rabljeno, Proizvajalec: PRÄWEMA, Tip: 205HS2-2 / Synchrofine, Leto izdelave: 2008, Št. proizvajalca: 077238, Krmiljenje, proizvajalec Rexroth Indramat, Tip System 200 BTV20, vključno z ročnim upravljalnim terminalom, Premer obdelovanca: 95 mm, Največja dolžina obdelovanca: 59 mm, Največja hitrost vretena C-obdelovanec: 6.000 [1/min] / 7.000 [1/min], B-nastavek vretena: 2.000 [1/min], Največji pomiki Z/X: 60 m/min, Hon-glava ZNG št. 416101804-8, leto izdelave 2008, Št. proizvajalca: 221, Postelja stroja iz granita, proizvajalec Eckbert Reitz, tip HFSL204HS2, leto izdelave 2008, Avtomatizacija obdelovanca, Preizkusna naprava za površinsko kakovost, Lovilna kad za olje, Črpalka proizvajalca Brinkmann, tip TH160/350-001, Delovne ure: 18.11.25 69518 Cedox Ahc Nopfx Ahxerb +++ Pozor: Pozicija je del spletne prodaje v prosti prodaji! +++

Stanje: rabljeno, Leto izdelave: 2004, Premer obdelovanca: 125 mm Modul: 4 Krmiljenje: SIEMENS SINUMERIK Pomik - x: 105 mm Pomik - y: 40 mm Pomik - z: 500 mm Premer obdelovanca: 17 - 39,5 mm Višina obdelovanca: 6 - 15 mm Stroji za honanje zobnikov | GLEASON-HURTH - ZH 125 Stroj je v zelo dobro vzdrževanem stanju. Crodpfex Szm Aox Ahxsb Upoštevajte, da so tehnični podatki povzeti po primerljivih strojih.

Stanje: dober (rabljeno), Leto izdelave: 2001, Opremljen z: - Power Stock - Fanuc 5-osni CNC krmilnik 160M - 400 mm brusilni (honi) kolut - Pulzni generator X-osi - Hladilni sistem z dvojnimi filtri - Magnetni separator ostružkov - Nastavljena honi orodja za zadnjo obdelavo še v stroju - Notranji premer honi orodja v stroju je 14'' - Delovna luč - Močratna vrata - Avtomatska odrezava (Auto Dress) - 5-delni program - Navodila za uporabo krmilnika 16M - Navodila za nastavitev in obratovanje Specifikacije: - Največji zunanji premer: 250 (350) mm - Najmanjši zunanji premer: 30 mm - Največja skupna dolžina: 400 mm - Največja širina zoba: 45 mm - Modul: 1,0–3,0 - Prečni pomik (Z-os): maksimalen hod 430 mm - Podajalna enota za brusilni kolut (X-os): maksimalen hod 370 mm - Enota za nihanje brusilnega koluta (C-os): kot nihanja +30° - Pogon za rotacijo brusilnega koluta (A-os): hitrost vretena do 500 vrt/min - Zunanji premer brusilnega koluta: 300 (400) mm - Največja širina brusilnega koluta: 50 mm - Kronirna enota (Y-os): maksimalen nihajni kot 1,6° - Tipi motorjev: - Pogon Z-osi: 1,8 kW - Pogon X-osi: 1,8 kW - Pogon Y-osi: 0,7 kW - Pogon C-osi: 1,8 kW - Pogon A-osi: 2,2/3,7 kW - Največja razdalja med konicami: 600 mm Crjdpfx Ahsrualpsxob - Višina konic: 1.100 mm - Tloris: 2.170 Š x 2.800 G x 2.100 V mm - Masa stroja: 4.500 kg

Stanje: dober (rabljeno), Premer kolesa - max. 145 mm Širina kolesa 110 mm Cedpey Ivdhofx Ahxorb Modul - max. 2 Modul - min. 0,3 Hitrost vrtenja 112 - 1000 obr/min Število zob - min. 6 Največja vpenjalna dolžina 150 mm Skupna potrebna moč 3,5 kW Teža stroja pribl. 1,3 t Potrebni prostor pribl. 1,3 x 0,8 x 1,4 m

Stanje: rabljeno, Leto izdelave: 2002, Technical specifications: Maximum wheel diameter: 200 mm Wheel width: 250 mm Maximum module: 3 Minimum module: 0.5 Total power requirement: 45 kW Codpey Nk Idjfx Ahxorb Machine weight approx.: 6.5 t Space requirement approx.: 4.4 x 2.4 x 2.7 m

Stanje: rabljeno, Leto izdelave: 1985, Technical details: Maximum wheel diameter: 780 mm Wheel width: 130 mm Maximum module: 10 Machine weight approx.: 8.5 t Strokes per minute: 30 spm Liebherr WSC501 CNC Gear Shaping Machine (used) Manufacturer: Liebherr Model: WSC 501 Machine No.: 4407/05 Year of manufacture: 1985 Details: Maximum shappable module: 8 mm (up to module 10 possible with 30° gears) Maximum gear width: 130 mm Machine table diameter: 500 mm Maximum workpiece diameter: 780 mm Distance (ram to machine table): 650 mm Minimum stroke rate: 30 strokes/min Infinitely variable, max. 1500 strokes/min Operating voltage: 380 V Frequency: 50 Hz Control voltage: 110 V Connected load: 36 kVA Maximum rated current: 55 A Weight: 8,500 kg Dimensions: approx. 4.85 x 3.655 x 3.78 m (WxDxH) The machine has seen very little usage and is currently still operational. It can be inspected by appointment, including a demonstration under power. Full documentation is available. Recommended applications: - Internal and external gearing in small batch sizes - Internal gearing in blind holes (non-through bores) - External gears without run-out where hobbing is not possible Typical components: Internal gear rings for planetary gearboxes, drive shafts, clutch hubs, etc. Attractive offer – Liebherr WSC501 CNC Gear Shaping Machine ✔ ISO 9001 + EN 9100 certified ✔ Robust German quality machine Cjdpfxjy Nk H Hs Ahxorb ✔ Rarely used – fully operational ✔ Demonstration possible by appointment Key advantages: - Suitable for internal and external gearing of small and medium series - Especially suitable for internal gears in blind holes - Perfect for external gears without run-out, where hobbing is not possible - Typical parts: internal gear rings for planetary gearboxes, drive shafts, clutch hubs, and more ✔ Major cost savings compared to new machines – with proven Liebherr quality Interested? Feel free to contact us for further information or to arrange a viewing.

Stanje: rabljeno, Leto izdelave: 2000, Technical details: Max. Wheel diameter: 130 mm Max. Module: 3 Total power requirement: 15 kW Approx. machine weight: 6 t Space requirement approx.: 2.3 x 2.5 x 2.17 m Well-maintained vertical CNC gear hobbing machine for shafts and gears With tailstock Also suitable for hard hobbing (ideal for steering pinions) Rapid traverse (radial, axial): 10,000 mm/min Rapid traverse (tangential): 7,500 mm/min Max. wheel diameter: 130 mm Max. module: 3 mm Tangential slide travel: 200 mm Radial slide travel: 10/100 mm Axial slide travel: 300/200 mm Crsdpfsy Nk Hgox Ahxsb Milling head speed: 250–3,500 rpm Milling head: +/- 40° swiveling Tool diameter: 80 mm Max. tool length: 240 mm Table speeds: 5–1,000 rpm Milling spindle drive: 15 kW Feed range: mm/min Table diameter: 132 mm Control: Sinumerik 840 C Connected load: 40 kVA Motor power: 15 kW Weight: 6 t Dimensions: 2,300 mm x 2,500 mm x 2,170 mm Equipment: Hydraulic workpiece clamping Automatic loading system Magnetic chip conveyor

Stanje: rabljeno, Leto izdelave: 2009, Gear diameter – external gearing: 1200 mm Gear diameter – internal gearing: 1200 mm Gear width – max.: 260 mm Workpiece diameter – max.: 1500 mm Control: Siemens 840 D Table diameter: 900 mm Table bore diameter / depth: 320 / 520 mm Max. table load: 95 kN Coolant pump: 120 l/min Distance between shaping spindle and workpiece table: 0–820 mm Shaping spindle diameter: 125 mm Tool holder: SK 45 DIN Table rotation speed: 12 rpm Drive power: 30 kW Machine weight: approx. 24 t Space requirement: approx. 11.715 x 5.565 x 4.505 m Strokes: - Stroke length min./max.: 0 mm / 270 mm - Adjustable stroke length: 270 mm - Stroke rate (double strokes): 10 to 270 DS/min Shaping head slide: - Max. traverse speed: 5000 mm/min Crjdpfxey Dvl Re Ahxeb Machine column: - Axial travel: 600 mm Shaping head: - Max. module for gear shaping: 16 mm - Shaping spindle diameter: 125 mm - Max. tool diameter: 300 mm - Max. shaping wheel speed: 25 rpm - Cutting speed: 5 ... 50 m/min Equipment/Accessories: - Lateral column adjustment: +/- 60 mm - Cutter holder: SK 45 DIN

Stanje: dober (rabljeno), Leto izdelave: 1984, Wheel diameter - max. 250 mm Wheel width 275 mm Module - max. 6 Machine weight approx. 5.5 t The ZFWZ 250 gear hobbing machine is designed for the efficient production of all hobbed cylindrical gears, such as: - Straight and helical gears, worm wheels and worms, splined shafts, keyed shafts, serrated gears, chain wheels, ratchet wheels, as well as conical and crown-shaped straight and helical gears. Change gears and milling accessories Technical Data: - Workpiece diameter (max): 250 mm - Module (max): 6 mm - Axial feed travel (max): 275 mm - Tangential feed travel (max): 100 mm - Helix angle (max): 45 degrees - Cutter diameter (max): 145 mm - Cutter length (max): 170 mm - Table clamping surface (min): 195 mm - Table clamping surface (max): 470 mm Performance Cutter speeds - Two-range, stepped: 56 ... 250 rpm - (Standard version): 90 ... 400 rpm - Infinitely variable in two ranges: 63 ... 180 rpm - (Special version with DC motor): 140 ... 400 rpm Cjdjv T Nqajpfx Ahxsrb Weight - Net weight of the machine: approx. 5,000 kg - Electrical cabinet: approx. 800 kg - Hydraulic unit + coolant tank + chip conveyor: approx. 700 kg Overall dimensions (with oil mist filter) - Length: Standard version: 3,950 mm DC drive: 3,450 mm (or 3,350 mm according to the table) - Width: 3,300 mm - Height: Machine: 1,980 mm Machine with DC drive: 2,150 mm Electrical cabinet: 2,200 mm

Stanje: rabljeno, Leto izdelave: 1989, Wheel Diameter - max. 400 mm Wheel Width 275 mm Module - max. 6 Machine Dimensions 300x310x245 cm Machine Weight approx. 5.0 t Specification: - Maximum wheel diameter: 400 mm - Min module: 1 - Max module: 6 - Table diameter: 370 mm - Maximum wheel diameter: with counter support: 340 mm / without counter brace: 400 mm - Max. axial offset: 275 mm - Max. tangential adjustment: 100 mm - Max. gear helix angle: 45 degrees - Max. cutter diameter: 145 mm - Max. hob length: 170 mm Performance - Cutter speed: 50-200 rpm - Axial feed, infinitely adjustable: 0.2-10 mm/rev - Tangential feed, infinitely adjustable: 0.1-5 mm/rev - Radial feed for spur gears: 0.1-4 mm/rev - Radial feed for worm gears: 0.025-1 mm/rev - Rapid traverse axial: 500 mm/min - Rapid traverse tangential: 250 mm/min - Radial rapid traverse for spur gears: 400 mm/rev - Radial rapid traverse for worm gears: 100 mm/rev - Motor power: 7.4 kW Weight - Machine 5,000 kg - Electrical cabinet approx. 800 kg - Hydraulic unit, coolant tank, chip conveyor approx. 700 kg Dimensions - Length with chain drive (standard) 2950 mm with DC drive 3350 mm - Width: 3100 mm - Machine height: 1980 mm Electrical cabinet approx.: 2400 mm Machine with DC drive approx.: 2150 mm Crodpfx Aou A I Elehxsb

Stanje: dober (rabljeno), Leto izdelave: 1981, Premer kolesa - maks. 650 mm Širina kolesa 450 mm Modul - maks. 10 Območje vrtljajev rezkalnega vretena 32–256 obr/min Električna izvedba - Napetost/frekvenca 380/50 V/Hz Obremenitev mize 1,8 t Maks. premer rezkarja 192 mm Maks. dolžina rezkarja 250 mm Vpenjalni stožec SK 40 Teža stroja pribl. 11,5 t Dimenzije (DxŠxV) pribl. 3,4x1,9x2,3 m LIEBHERR - L652 - Stroj za odvalno rezkanje zobnikov Crsdpfsy H Nz Dex Ahxeb

Stanje: dober (rabljeno), Maximum wheel diameter: 630 mm Wheel width: 375 mm Maximum module: 10 Clamping table: 550 mm Table bore: 125 mm Csdpfxsua It Uj Ahxjrb Cutter speed, infinitely variable: 62 - 390 rpm Spindle taper: Morse 5 Axial feed: 0.40 - 6.80 mm/rev Radial feed: 0.10 - 1.76 mm/rev Distance between milling spindle and clamping spindle: 50 - 425 mm Minimum number of teeth: 8 Cutter diameter x width: 192 / 215 mm Cutter stroke: 200 mm Main drive motor: 7.5 kW Total power requirement: 21 kVA Machine weight approx.: 8.2 t Machine equipment: - Universal milling head with tangential adjustment - Pressure reducing valve for counterholder - Magnetic chip conveyor - Year of manufacture: approx. 1976

Stanje: rabljeno, Leto izdelave: 1998, Workpiece diameter with 1:10 ratio: 300 mm Workpiece diameter with 1:1 ratio: 212 mm Number of teeth – max.: 200 Number of teeth – min.: 6 X travel: 300 mm X-axis speed: 0.1–5,000 mm/sec Y travel: 400 mm Y-axis speed: 0.1–5,000 mm/sec A-axis: -170° / +170° Control system: Siemens Sinumerik 840 C Total power requirement: 38 kW Machine weight approx.: 10 t Space requirement approx.: 4.20 × 2.20 × 2.10 m Codoul El Tepfx Ahxerb

Stanje: rabljeno, Wheel diameter – max. 0-200 mm Credstuxa Ujpfx Ahxjb Module – max. 25 Module – min. 0.5 with accessories and under-table Year of manufacture approx. 1995

Stanje: rabljeno, Leto izdelave: 2008, Siemens 840D Control Gear Hobbing Machines for Large Gears Flexible and Universal Gear Hobbing for Large Gears Large gear hobbing machines from Gleason deliver maximum productivity for roughing and finishing cylindrical gears serving various industries: wind turbines, industrial gearboxes, mining and marine applications, gear manufacturing, and more. The guideways are wide and fitted with hydraulically preloaded guides, used in combination with separate linear guidance systems and backlash-free rollers. This ensures precise slide movements during every feed operation. Crodpfxowzypns Ahxob The work table’s design provides optimal conditions for absorbing and transferring cutting forces to the machine base. The use of hydrostatic table bearings, combined with the proven backlash-free double worm gear drive, guarantees precise table movements and highest flatness as well as concentricity accuracies—regardless of significant fluctuations in workpiece weight and/or high machining forces. The motorized hob heads for external and internal gears are designed to meet the requirements of modern cutting tools. All machine sizes can be equipped with both external and internal gear hob heads. The drive’s power range anticipates future tool developments. Naturally, the hob head drive is backlash-free as well. These machines are particularly suited for the use of state-of-the-art cutting materials, whether dry or wet machining is preferred.

Stanje: dober (rabljeno), Leto izdelave: 1995, Funkcionalnost: popolnoma funkcionalen, The perfect retrofit machine! Mechanically in exceptional condition! This machine can be inspected under power until 12.05.2026. After this date, it will be dismantled due to space constraints. Please find attached the current KLINGELNBERG measurement protocols available for download. Gleason P 800 Year of manufacture: 1995 Control: SIEMENS 840 C (discontinued) Condition: Mechanically in very good condition Functionality: Fully operational Inspection: Possible under power Technical specifications: - Rated workpiece diameter: 800 mm - Max. workpiece diameter: 800 mm - Max. workpiece diameter, special version: 1,200 mm Crsdpfey Hfm Nox Ahxjb - Rated module: 20 / 30 mm - Rated module, special version: 25 / 35 mm - Drive power: 35 kW - Drive power, special version: 52 kW - Cutter head speed range: 20 - 200 rpm - Cutter head speed range, special version: 26 - 265 rpm - Additional cutter head speed range, special version: 36 - 360 rpm - Swivel range of cutter head: +30 / -45 degrees - Cutter head dimensions (standard cutter head), diameter/length: 350 / 375 mm - Center distance workpiece/tool, min./max.: 50 / 600 mm - Center distance workpiece/tool, special version: 50 / 800 mm - Max. axial slide travel: 700 mm - Max. axial slide travel, special version: 1,000 mm - Max. axial slide travel, special version: 1,300 mm - Lowest cutter head position above table: 450 mm - Table diameter: 800 mm - Table bore diameter: 245 mm - Table bore depth: 875 mm - Max. table speed: 15 rpm - Max. table load: 10,000 kg Machine dimensions: - Width A: 5,800 mm - Length B: 6,900 mm - Height C: 4,700 mm - Machine weight: 22,000 kg Regarding the values of the current KLINGELNBERG gear measurement reports before the grinding process: "Pitch and lead are unremarkable. In the profile, one measurement shows an fHα deviation at the limit or slightly outside the tolerance. Please check whether this value is permissible according to the drawing/customer approval or if correction or reworking is required. The gears have always been passed on to the RZ 1000 REISHAUER for grinding and were ground accordingly. Nevertheless, an overhaul of the C-axis is recommended. A cost estimate from GLEASON PFAUTER LUDWIGSBURG is available. Estimated cost: 10,000 EUR."

Stanje: rabljeno, Leto izdelave: 2000, Technical Details: Wheel Diameter - max.: 275 mm Wheel Width: 55 mm Module - max.: 6.5 Module - min.: 1.5 Face Hobbing - Continuous Process Continuous Method: Workpiece and tool (usually Spiron) rotate simultaneously; all teeth are generated in a single working cycle. The cutter head has several groups of cutters (not arranged in a circle). Teeth profile of constant height. Tapered tooth top surface. Single Indexing Method: The workpiece remains stationary and the tool (usually Arcon) rotates and cuts a tooth by plunging in. Once one tooth is cut, the tool retracts from the tooth space, the workpiece rotates by one tooth width, and the next tooth is cut. This is repeated until all teeth are completed. The cutter head has all cutters arranged on a circular path. Tapered tooth height. Parallel tooth top surface. Credpfxov N Hils Ahxjb The C28 is capable of both operations, gear + pinion. For the single indexing process, however, the C28 has to be 'prepared.' This means: direct measuring system + component gearbox brake for the workpiece axis + license file for producing single indexing process.

Stanje: dober (rabljeno), Premer kolesa – maks. 600 mm Modul – maks. 6 Dimenzije D-Š-V 2540 x 1500 x 1920 mm Premer mize 160 mm Teža stroja pribl. 3,6 t Visoko zmogljiv stroj za radialno valjčno rezkanje zobnikov Zobni kot 15° Širina zoba 270 mm Premer kolesa 620 mm Zobni kot 30° Širina zoba 250 mm Premer kolesa 610 mm Crsdpfx Aoy E Twgjhxob Zobni kot 45° Širina zoba 200 mm Premer kolesa 500 mm Zobni kot 60° Širina zoba 100 mm Premer kolesa 450 mm Največji premer rezkarja 105 mm Največja širina rezkarja 115 mm Premer vpenjalne mize 420 mm Vrtina vpenjalne mize 75 mm Globina vrtine pod površino mize — mm Premer zobniškega segmenta 450 mm Vpenjalni drog 30 mm Rezkalni drogovi 22–27–32 mm

Stanje: rabljeno, Leto izdelave: 1963, Technical details: Max. wheel diameter: 900 mm Max. module: 10 Approx. machine weight: 8,200 kg Max. hob diameter: 190 mm Crjdevkpu Hopfx Ahxsb Max. hob length: 320 mm Infinitely variable hob speeds: 13–80 rpm Max. workpiece length: 750 mm Max. workpiece diameter: 150 mm LIEBHERR Gear Hobbing Machine L 900 Counter-support arbor missing

Stanje: zelo dobro (rabljeno), Leto izdelave: 2002, Premer kolesa - maks. 350 mm Širina kolesa 230 mm Modul - maks. 8 Modul - min. 1 Krmiljenje Siemens 840 Teža stroja cca 10,5 t Crjdpfx Asy D T Upehxjb Potrebni prostor cca 4,5 x 2,5 x 3,0 m Naprava za nakladanje/razkladanje

Stanje: rabljeno, Leto izdelave: 2002, Tehnične podrobnosti: Codpfx Ahsx Ea Ipsxjrb Največji premer kolesa: mm Širina kolesa: mm Približna teža stroja: 7000 kg Potreben prostor približno: 9130 x 3895 x 3450 mm Največji dovoljen delilni premer: 80 mm Največja dolžina ozobljenja: 170 mm Skupna dolžina: 240 mm Vpenjalni premer: 32 mm Premik sani radialno (X-os): 100 mm Premik sani tangencialno (Y-os): 160 mm Aksialno gibanje Z-osi: 300 mm/min Vrtina glavne gredi obdelovanca: 45 mm Električna priključna moč: 44 kVA

Stanje: rabljeno, Leto izdelave: 2007, Premer kolesa - maks. 380 mm Širina kolesa 540 mm Modul - maks. 7 Krmiljenje SINUMERIK 840 D Aksialni hod 600 mm Premer mize 317 mm Hitrost mize 100 obr/min Rezkalna glava - vrtljiva + / - 35 stopinj Pogon rezkalne vretena 27,00 kW Hitrosti rezkala - brezstopenjsko 1500 obr/min Premer rezkala 160 mm Dolžina rezkala maks. 330 mm Hitrosti rezkalne glave maks. 3000 1/min Premer valjčnega rezkala - maks. 160 mm Dolžina valjčnega rezkala - maks. 330 mm Tangencialni hod maks. 300 mm Aksialna hitrost 10.000 mm/min Tangencialna hitrost maks. 3000 mm/min Radialna hitrost 7.500 mm/min Vsebina olja 100 l Vsebina hladilne tekočine 780 l Hod kontrastebra 540 mm Skupna potrebna moč 50,00 kW Teža stroja pribl. 16,00 t Potreben prostor pribl. 6,00 x 4,50 x V3,50 m Crjdpfx Asyt Rvhjhxeb za naslednje postopke: aksialno valjčno rezkanje, posamezno rezkanje, rezkanje polžastih koles, poševno rezkanje, ogobljanje; NC-kontrastojalo

Stanje: rabljeno, Funkcionalnost: popolnoma funkcionalen, Maksimalni delovni premer: 2100 mm Velikost mize: 1800 mm Crjdpfx Ajylprfshxeb Maksimalni modul: 20 Teža: 40 ton

Stanje: dober (rabljeno), Opis: Cedsy Amiqopfx Ahxorb Stroj je v dobrem tehničnem stanju, možnost preizkusa po predhodnem dogovoru. Uporaba: proizvodnja zobnikov (čelnih, poševnih, osi). KAPACITETA maks. premer zobnika: ≈ 400 mm maks. modul: običajno 6–8 (včasih do 10 pri novejših verzijah) maks. širina zobnika: približno 275–400 mm VRETENO IN ORODJE obrati rezkarja: do ~500 vrt/min premer orodja: približno 160–240 mm moč motorja: približno 15–17 kW MIZA premer mize: ≈ 380–400 mm odprtina v mizi: približno 80 mm obremenitev: do ~1000 kg DIMENZIJE IN TEŽA dolžina: ~4680 mm širina: ~2395 mm višina: ~2515 mm teža: približno 5–6,5 t (klasična različica)

Stanje: rabljeno, Leto izdelave: 1969, Wheel diameter - max. 160,175 mm Wheel width 355 mm Module - max. 4.5 Spindle bore 75 mm Centre distance between centres 410 mm Number of teeth - min. 2, 3 Cutter diameter max. 115 mm Cutter length max. 105 mm Axis distance between cutter and workpiece - max. 138 mm Axis distance between cutter and workpiece - min. 30 mm Milling head - swivelling 120° Cutter speeds 70 - 400 rpm Axial feeds 0.25 - 4.0 mm/rev Radial feeds 0.09 - 1.5 mm/rev Total power requirement approx. 9.5 kW Machine weight approx. 3.5 t Space requirement approx. 1730x1400x1440 mm Equipment/accessories: - Change gears - Milling arbors - Clamping devices Codpfx Ajvzhf Sehxorb - Documentation