Description

1. Part-number breakdown DYJ705 = Valin belt-drive series, 7.5 kW @ 1 500 rpm, 48 N·m rated torque, 6-pole induction motor, 400 VAC, IP54, –25 °C…+70 °C
   Belt: 180 mm wide, 12 mm thick, polyamide cord, 85 N/mm tensile strength, 1 % elongation @ 3 000 N
   Sheave: 250 mm Ø, 5 × 12 mm grooves, phosphate + epoxy paint, dynamic balance G2.5
   Bearings: sealed SKF 6313-2RS1, grease life 40 000 h @ 75 °C
   Brake: twin-disk 110 VDC, 2 × 800 N static, manual release lever, micro-switch verified
   Frame: cast iron GG-25, torsion-proof foot pattern 420 × 200 mm, mass 185 kg
2. Safety first—lock-out & verify The machine remains on the 400 VAC rail and 110 VDC brake circuit. Lock the main disconnect, hang a lock-out tag and wait 5 min for the DC bus to fall below 5 V. Confirm zero energy with a CAT-III meter before touching any terminal.
3. Mechanical mounting—keep the belt vertical Use four M20 foundation bolts, grade 12.9, torque 300 N·m.
   Maintain 200 mm clearance around the belt guard; every 10 °C rise halves bearing grease life.
   NYE supplies a free lifting beam (NY-BEAM-DYJ705) and anti-vibration pads (NY-AVP-DYJ705) to reduce structure-borne noise 4 dB(A).
4. Belt alignment & tensioning a) String line from car to counter-weight sheave; lateral offset must be <0.3 mm.
   b) Place belt on sheave; ensure 2 mm clearance to side walls.
   c) Apply 3 kN tensioning force (use NY-HYDRA-DYJ705); frequency must be 85 Hz ±2 Hz for 1 800 mm centre distance.
   d) Every 0.5 mm under-tension reduces belt life 20 %.
5. Belt wear limits Cord exposure >1 mm across 10 % of width → replace belt.
   Edge fraying >3 mm → replace belt.
   Elongation >1.5 % → re-tension; >2 % → replace belt.
   NYE offers genuine Valin belt (NY-BELT-DYJ705-180) with pre-marked wear indicators.
6. Bearing life model Grease life: 40 000 h @ 75 °C, doubles every 10 °C drop.
   Translate to elevator duty: Light traffic (residence, 300 trips/day) – 109 k h/year → bearings ≈ 15 years; inspect every 3 years. Medium traffic (office, 600 trips/day) – 219 k h/year → bearings ≈ 8 years; inspect every 2 years. Heavy traffic (mall/metro, 1 200 trips/day) – 438 k h/year → bearings ≈ 5 years; inspect every 6 months.
7. Vibration & balance check Run elevator at 1.6 m/s; vibration <1.5 mm/s RMS on bearing housing (ISO 10816).
   If >3 mm/s, balance has shifted—replace machine immediately.
8. Magnet degradation check Induction motor: no permanent magnets; stator IR >500 MΩ @ 500 V.
   If IR <100 MΩ, stator is moisture-contaminated—replace machine.
9. Replacement cycle summary Light traffic – belt ≈ 12 years, bearings ≈ 15 years, full machine ≈ 18 years; inspect every 3 years. Medium traffic – belt ≈ 6 years, bearings ≈ 8 years, full machine ≈ 10 years; inspect every 2 years. Heavy traffic – belt ≈ 3 years, bearings ≈ 5 years, full machine ≈ 7 years; inspect every 6 months. Always replace encoder coupling and brake discs when bearings are changed—labour overlap saves 1 h.
10. Rapid swap (downtime < 4 h) a) Secure car on rail clamps, lock-out power.
    b) Release belt tensioner, remove belt.
    c) Sling old machine, remove foundation bolts, lower 185 kg to pallet.
    d) Offer new NYE DYJ705, align with existing shim.
    e) Install belt, apply 3 kN tension, run balance test.
    f) Full-load dynamic test: 125 % rated load, 1.6 m/s, vibration <1.2 mm/s RMS.
    g) Log serial number, cycle counter, belt tension; return old unit for core refund.
11. Recycling & sustainability Nanjing Zhuye pays USD 200 core credit per DYJ705. Steel frame is shot-blasted and reused for counter-weights, copper windings remelted 99.95 %, belt cords recycled for industrial yarn. One recycled machine saves 1.1 t CO₂—equal to the elevator’s standby consumption for 3 months.