STAR series 89 2-Stage Servovalve Rated flows up to 2 l/m Features Maximum operating pressure 15 bar ISO 172-5-2 mounting pattern Internal pilot supply (4 port) Suitable for -way or 4-way applications Low hysteresis & zero point drift High spool drive forces Spool in bushing design Dry torque motor with mechanical feedback Long life Sapphire Technology Star Hydraulics Limited Severn Drive Tewkesbury Business Park Tewkesbury Gloucestershire GL2 8SF England (UK) www.star-hydraulics.co.uk ST-896.1-En
Benefits and Features Sapphire ball in slot design Incorporated into Star designs since 1988 Many billions of cycles per service life Increased spool life due to spool rotation Ultra low coefficient of friction sapphire to steel Feedback mechanism unhindered by spool rotation Extended warranties available Safety Flame proof Intrinsic safety Class, Div & Zone coverage Mechanical failsafe Double & triple coil redundancy Quality Independant audit process is our commitment on quality Focus on customer needs and expectations Delivery schedules on time Continual improvements on products and services Maintaining design and manufacturing integrity Custom spool lap & bushing port geometries Zero overlap Overlap (closed center) underlap (open center) Dual gain Asymmetric gain Special projects Compact servo designs Special interfaces Modular components Sapphire flow Ensuring first stage stability Precisely matched flow properties Long life in extreme environments Sealing materials Nitrile Fluorocarbon (Viton) Ethylene-Propylene Fluorosilicone Special connectors MIL-C-515 MIL-DTL-8999 Conduit style male/female Hermetic
Technical data Hydraulic Nominal flow ratings [±1%] at 7 bar Dp 95, 15, 2 l/m Operating pressure (max) Ports P, C1, C2, R R Seal material NBR, FPM 15 bar 15 bar EPDM 28 bar 21 bar Fluid viscosity range (recommended) Fluid type 1 to 1 mm 2 /s (cst) Mineral oil to ISO 11158, DIN 51524 or equivalent MIL-H-566 Skydrol Kerosene Water glycols others on request Filter rating (recommended) Pressure line Beta 1 = 2 (1 µm abs), non by-pass & indicator Off-line Beta 2 = 1 (2 µm abs) Fluid cleanliness ISO 446: 1999 minimum 16/ 14/ 11 recommended 15/ 1/ 1 Operational parameters Hysteresis Threshold 4.% without dither 1.5% without dither Null shift T 4 C.% Internal leakage 14 bar supply (1% overlap) 95 l/m 2. l/m 15, 2 l/m 4. l/m Load pressure difference 1% input % of supply pressure can be as high as 1% Response time -1% rated spool stroke 95, 15 l/m 18 ms 2 l/m 6 ms Mounting pattern ISO 172-5-2 without X port Mounting position Any, fixed or movable (1) Weight std unit.4 kg additional filter housing 4.7 kg Design protection EN 6529 IP 65 Shipping protection Vibration Shock Seal material options Sealed base plate g all axis, 5 Hz to 2, Hz g all axis NBR, FPM, EPDM Temperature range - to 15 C (1) Depending on valve orientation the main stage spool may drop when supply pressure is switched off leading to unwated startup bump. If so then an external pilot supply model (892) is suggested, this allows startup of the first stage via the X port prior to applying pressure at the main stage.
Technical data Electrical Rated input ± (ma) single (differential) 8 15 4 1 2 Other coil rates available series 4 7.5 15 2 5 1 parallel 8 15 4 1 2 Coil resistance (W) per coil 1 2 8 28 22 Power (W) single.64.45.27.128.28.88 series.2.2.15.64.14.44 parallel.2.2.15.64.14.44 Connector pin out identification A B C D Polarity P»C2, C1»R single A +, B - or C +, D - series parallel A +, D -, B & C linked A & C linked +, B & D linked Valve connector type MIL-C-515 MS12E-14S-2P mates with MS16F-14S-2S Consult factory for more options Standard connector orientation C2 port also available over C1 port; please advise when ordering N.B. 15 ma 2 ohm coil rate not available with rated flow of 2 l/m.
Internal leakage (l/m) % Supply pressure % Rated flow Flow rate Q (l/m) Technical data Output Polarity (per std wiring) Flow for 1% input as a function of valve pressure drop 1 75 P»C2, C1»R 5 25 1-25 -5-75 P»C1, C2»R -1-1 -75-5 -25 25 5 75 1 % Rated input signal 1 1 7 1 Valve pressure drop p (bar) Typical Load Pressure Difference v Input Signal The flow tolerance for standard servovalves is ±1% of the rated flow at 1% rated input signal. 1 8 6 4 2-2 -4-8 Rated Signal [In] is the specified input voltage or current of either polarity to produce rated flow. Rated input does not include null bias values. Rated flow corresponds to the flow at rated input at 1 bar or 7 bar, with no load, therefore in 4-way valves there will be a pressure drop of 5 bar or 5 bar respectively across each land. Load pressure difference versus input signal indicates typical differential pressure gain between ports C1 (A) and C2 (B) for standard lap spools. Negative and positive overlap change this characteristic signifcantly. Internal leakage comprises of tare first stage and laminar leakage between spool and sleeve. With critical lap conditions in 4-way designs the leakage peaks through the null region. -1-5 -4 - -2-1 1 2 4 5 % Rated input signal Internal Leakage v Input Signal (Qn = 95 l/m) 5 4 2 1-1 -8-4 -2 2 4 6 8 1 % Rated input signal
Technical data Freq. Response Qn 95 & 15 l/m at 25% In, 21 bar Freq. Response Qn 95 & 15 l/m at 1% In, 21 bar - -27 - -27 1 1 1 1 1 1 1 1 Freq. Response Qn 2 l/m at 25% In, 21 bar Freq. Response Qn 2 l/m at 1% In, 21 bar - -27 - -27 1 1 1 1 1 1 1 1 Frequency Response at 25% In Frequency Response at 1% In - -27 -. -27 1 1 1 1 1 1 1 1
89 series INSTALLATION DETAILS STAR Mounting screws Skt head cap screws M1 x 55 1.9 ISO 4762 Null adjust (Mechanical) -. hex skt & 1 A/F lock nut - slacken lock nut (ccw) half-turn with 1 A/F ring spanner - insert. hex key into socket and rotate to obtain required null / offset value - hold hexagon key in desired position then tighten lock nut to Nm Porting details P, C1, C2, R ports 15.8, 2.8 1.4 on 5.8 P.C.D. Interface seals Ports P, C1, C2, R - ID 2.5 x 1.78 O-Ring (1) Optional filter housing Replacement cartridge PN: SRS1479 1 17 118 12 7 6 5 14 4 PIN D PIN A PIN C PIN B Mechanical null adjust 1 88 Mounting interface conforms to ISO 172-5-2 (X port must not be used) P C1 C2 R X F1 F2 F F4 G size 15 15 15 15 - M1 M1 M1 M1 8 9 x 6.5 11.1 61.9 6.5-7 7 11.1 14 min. 7.7 6. 92 min. F1 G C1 P X C2 F2 y 17.8 42.8 42.8 68.2-85.6 85.6 2.7 Surface flat within.1 / 1 : finish better than.8 μm F4 R F