Danfoss Eaton Replacement BMS BM6 Orbital Motor | BMS160 BM6-315 BM6-800 Hydraulic Motor

The BMS (matching OEM OMS specifications) and BM6 (matching OEM OMV specifications) series heavy-duty disc-valve orbital hydraulic motors manufactured by Chengyuan Hydraulic are low-speed high-torque (LSHT) fluid rotary drive solutions fully engineered to match premium global industrial footprints. This professional product series serves as the primary technical vector for demanding mobile machinery tracking, geological drilling rotators, heavy mining conveyor drives, and marine winches. This comprehensive product portfolio natively covers critical heavy displacement strings, including the medium-heavy BMS-80, BMS-130, BMS-160, and the massive torque variants: BM6-250, BM6-315, BM6-400, BM6-625, BM6-800, and BM6-985. Featuring robust Geroler roller-star gear sets and an independent disc valve distribution platform, these motors thrive under massive structural side-loading and high case pressure spikes. Every singular orbital motor undergoes 100% simulated load testing for intermittent peak limits, breakaway torque stability under full resistance, and bi-directional seal retention prior to packaging to ensure original-matching specifications and deliver proven 100% original-place interchangeable compatibility.

Technical Specifications :

• Core Product Framework: BMS (OMS Type) & BM6 (OMV Type) Series Heavy-Duty Disc Valve Orbital Hydraulic Motors

• Model Designations Covered: BMS-80 / BMS-130 / BMS-160 / BM6-250 / BM6-315 / BM6-400 / BM6-625 / BM6-800 / BM6-985

• Geometric Volumetric Displacements:

  • BMS Series Cadence: 80.5 $cm^3/rev$ / 130.2 $cm^3/rev$ / 160.8 $cm^3/rev$

  • BM6 Series Cadence: 250.5 $cm^3/rev$ / 315.8 $cm^3/rev$ / 401.2 $cm^3/rev$ / 629.1 $cm^3/rev$ / 801.5 $cm^3/rev$ / 985.0 $cm^3/rev$

• Maximum Continuous Operating Pressure:

  • BMS Framework: Rated up to 21 MPa (210 bar / 3045 psi)

  • BM6 Framework: Rated up to 20 MPa (200 bar / 2900 psi, graded downwards down per volumetric displacement peaks; e.g., BM6-985 is bound to a 12 MPa continuous limit)

• Intermittent Peak Pressure Threshold: Ranges from 24 MPa up to 28 MPa (240 bar ~ 280 bar / 4060 psi)

• Maximum Continuous Output Torque:

  • BMS-160 Specification: Rated up to 480 N·m (4248 lb·in)

  • BM6-315 Specification: Rated up to 950 N·m (8408 lb·in)

  • BM6-800 Specification: Heavy peak rating up to 1880 N·m (16639 lb·in)

• Permissible Continuous Speed Envelope:

  • BMS Low-Displacement Limit: Up to 800 rpm

  • BM6 Large-Frame Speed Band: 150 rpm to 500 rpm (authorizing excellent low-speed smooth velocity modulation)

• Radial & Axial Dynamic Loading Limits: Main output drives across the BM6 frame integrate massive twin tapered bearings supporting direct external continuous side loads up to 25-30 kN

• Port Configurations & Mechanical Interfaces: Standard 4-hole SAE 4-Bolt square or wheel-mount templates; main process terminals configured in G 3/4 (BMS) or G 1 (BM6) threads accompanied by a distinct G 1/4 independent external case drain terminal.

Key Technical Advantages:

• Hydrostatically Balanced Independent Disc-Valve Distribution: The BMS and BM6 architectures depart from basic shaft-distribution routing, deploying an isolated, precision-ground end-face disc valve array instead. Driven by the localized differential fluid chambers, the disc valve undergoes continuous axial clearance hydrostatic compensation. This prevents internal bypass cross-leakage even when the outer iron housing experiences micro-deflections under severe thermal or torque stresses, holding volumetric efficiency above 92%.

• Super-Finished Profile-Corrected Geroler Star Curve Blueprints: The internal rolling-contact Geroler gear sets feature computer-optimized, profile-corrected non-conjugate curves. Precision-polished on high-tier multi-axis CNC micro-grinding centers, the mirror-finished contacting boundaries smooth out localized oil channel pressure transitions. This setup completely eliminates low-speed stick-slip crawling and breakaway torque drop-offs, guaranteeing smooth torque output at speeds below 10 rpm.

• Integrated Dual Heavy-Duty Tapered Roller Bearing Glands: The forward housing of the motor body integrates two pre-loaded, high-dynamic capacity tapered roller bearings. This structural configuration enables the heavy forged output shaft (configured in straight keyed, splined, or tapered formats) to absorb massive external radial vectors and heavy bi-directional thrust loads from direct sprockets, wheels, or crane drum linkages without requiring external bearing pedestals.

• Case-Hardened and Carburized High-Torque Cardan Shaft Links: The central cardan drive shaft, the structural lifeline transmitting torque from the orbiting star to the output nose, is formed from premium alloy steel. Subjected to deep-case carburizing thermal hardening and match-ground spline treatments, it exhibits exceptional torsional fatigue resistance. This reduces gear spline wear velocities by 40% under severe bi-directional duty cycles.

Application Areas:

• Heavy Drilling, Boring & Construction Infrastructure: Main rotational drives for rotary drilling rigs, thrust/rotation actuators for Trenchless Horizontal Directional Drilling (HDD) units, and heavy continuous crawler wheel undercarriages.

• Heavy Aggregate, Cement & Processing Material Conveyors: High-torque direct-drive drums for surface mining belt lines, massive stone apron feeders, scrap scraper networks, and ball-mill material charging locks.

• Marine Deck Machinery & Upper Crane Attachments: Heavy shipboard anchor mooring windlass winches, main hoist hoist drums for marine cranes, and industrial logging or scrap-handling hydraulic grapples.

Expert Maintenance Tips:

• Mandatory Unobstructed Routing of External Case Drain Pipeline: Because the heavy-duty BMS and BM6 units endure continuous resistive loads and rapid operational reversals, the internal casing cavity experiences aggressive交变 fluid pressure accumulation. You must connect the G 1/4 case drain port back to the reservoir via a dedicated, independent line—never merge this line directly with a high-pressure main T-return collector line. Keep case backpressures strictly below 2 MPa to prevent shaft seal lip blowout and severe external leakage.

• Pre-Lubrication Case Priming & Low-Speed Air Bleed Protocols: Large displacement profiles like the BM6-625/800 contain massive internal fluid columns. Never cycle a newly installed motor under heavy external loading while dry. You must pre-fill the motor housing with clean, system-matched hydraulic fluid through the case drain port prior to startup. During the initial startup cycle, operate the motor completely unloaded under 50 rpm for 5 to 10 minutes to purge air bubbles from the disc valve galleries and establish proper hydrodynamic lubrication films.

• Enforce Strict Fluid Cleanliness Regimes to Abate Spalling Failure: Because disc-valve heavy orbital motors rely on high-load line-contact rolling friction across the Geroler star profiles, they are highly vulnerable to hard suspended solids (such as wear fines or quartz dust). The filtration system must be armed with dynamic differential pressure signaling indicators and filters rated at $\beta_{10} \ge 100$ (ISO 4406 must be held at 19/16/13 or cleaner). Contaminated medium induces early pitting and micro-spalling on the roller tracks, triggering large internal bypass flow losses and thermal power loss.