B6K Disc Valve Orbital Hydraulic Motor 195-985 Cc/Rev

B6K orbital hydraulic motor for low speed, high torque drives

The Olive Branch Hydraulics B6K hydraulic motor uses disc valve distribution and a geroler mechanism across eight nominal displacements from 195 to 985 cc/rev. The standard motor output shaft uses heavy tapered roller bearing support with a locking arrangement to set bearing clearance.

Select the small-flange or large-flange standard motor, 6KW wheel motor, or 6KS bearingless version from its own installation drawing. The three photographs illustrate a standard-family motor from different views; the ordered displacement, shaft, flange and port package must be agreed separately.

Configuration and installation choices

Small-flange choices differ even when they look similar: the ordering table gives F1 a 125 mm pilot with four 14 mm holes on a 160 mm bolt circle; F2 has a 127 mm pilot with four 14.5 mm holes on a 162 mm circle; F3 uses four 17 mm holes on a 162 mm circle with a 127 mm pilot.

The F4 large-flange drawing specifies a 160 mm pilot, four 18 mm holes and a 200 mm bolt circle. F5 wheel mounting uses a 139.7 mm pilot and 184.15 mm bolt circle with four 14.3 mm holes; F6 bearingless uses a 127 mm pilot and 162 mm bolt circle.

Shaft profiles and port connections

• A1 rectangular spline: 6D40 × 35 × 10, with M8 axial thread.
• A2 keyed shaft: 38.1 mm diameter, nominal 9.53 mm square key, with 3/8-16 UNC axial thread.
• A3 rectangular spline: 8D42 × 36 × 7; A4 is a 42 mm keyed shaft with A12 × 8 × 63 key.
• A5 and A6 are 40 mm keyed shafts with different key lengths and projections; compare the individual drawings.
• A8 is a 17-tooth 12/24 DP, 30° involute spline; A9 is a different 17-tooth module-2.5 spline.
• A13 and A14 wheel shafts use different 1:8 and 1:10 tapers; do not substitute them by appearance.
• A15 bearingless output is a 12-tooth, 8.5/17 DP spline with 30° pressure angle.

The catalogue contains 24 port packages rather than a universal connection. P1–P9 use the standard staggered or plate-face arrangements; P10–P24 use rectangular arrangements with different main threads, drains and mounting patterns.

Port thread labels containing UN/UNF designations must be verified against the approved thread and sealing specification. Do not infer main-port depth from plate mounting holes, or assume the rectangular and staggered faces share dimensions.

Ratings, disputed speed entry and hydraulic circuit

The summary lists 150 L/min continuous flow for all eight sizes. Continuous pressure is 170 bar for the 195 through 490 sizes and 120 bar for the 625, 800 and 985 sizes; continuous torque is displacement-specific and is not a combined maximum-speed operating point.

B6K-310 continuous speed is pending confirmation. Its summary entry of 698 rpm exceeds the listed 485 rpm intermittent speed and conflicts with the chart, so the specification table marks this cell for confirmation rather than presenting it as a verified usable rating.

Other performance-curve boundaries also differ from the summary. Use the summary for initial comparison, then confirm actual torque, rpm, flow and pressure together; intermittent duty must not exceed 6 seconds per minute and recommended system temperature must not exceed 82°C.

Facing the output shaft, the standard diagram gives clockwise rotation with A inlet / B outlet, and counterclockwise rotation with B inlet / A outlet. Confirm the R/L order code and physical port position before connecting the circuit.

The catalogue mentions 310 bar transient inlet and return peaks. These do not establish universal continuous return or seal pressure limits; permissible case pressure, external drain and series/parallel operation depend on the actual seal, speed and hydraulic circuit.

Equipment applications and drive selection

The catalogue identifies agricultural and forestry machinery, oil-industry equipment, machine tools, lifting, construction, drilling and engineering vehicles as application fields. These are selection contexts; no named equipment model fit is established.

1. Send the original full model/OEM number, nameplate photographs and machine make/model.
2. Measure pilot, hole diameter and bolt circle, flange thickness and installation envelope.
3. Identify the shaft keyway or spline, axial thread, projection and coupling.
4. Confirm main ports, drain, sealing faces, port orientation and any mounted valves.
5. State continuous torque/rpm, starting load, pump flow, pressure, temperature, back pressure and duty cycle.
6. Specify standard, wheel, bearingless or brake arrangement, load support, quantity and destination.

Parking-brake version

The separate 6KB drawing describes parking-brake service and explicitly excludes dynamic braking. Do not apply the standard motor table as a brake holding-load specification; release pressure, permitted holding torque and working pressure/flow must be confirmed for the selected brake assembly and circuit.

The brake drawing also uses a 395 size label where the standard summary uses 390, so verify the intended configuration from the complete drawing and order code. A hydraulic motor alone should not be treated as an independently verified load-holding system.

Model names and original-number enquiries

Common identification formats include B6K195 / B6K 195 / B6K-195; B6K245 / B6K 245 / B6K-245; B6K310 / B6K 310 / B6K-310; B6K390 / B6K 390 / B6K-390; B6K490 / B6K 490 / B6K-490; B6K625 / B6K 625 / B6K-625; B6K800 / B6K 800 / B6K-800; B6K985 / B6K 985 / B6K-985. The catalogue ordering family uses 6K, 6KW and 6KS; the brake arrangement is separately labelled 6KB/B6KB.

Buyers may compare BM6, BMK6, OMT, BMT or Char-Lynn 6000 families during a replacement search. These comparison names do not establish a direct interchange; the complete shaft, flange, ports, seals, drain, load and ratings must match the application.

Danfoss PowerSource identifies original part 612-1021-1 as a Char-Lynn 6K Series motor with a 195 [11.9] size description. This is an original-number enquiry reference, not a confirmed B6K replacement or an Olive Branch order code.

International terms include motor hidráulico orbital B6K, moteur hydraulique orbital B6K and гидромотор B6K. Include the full original number and dimensions when asking for a match.

Frequently asked questions

Is B6K a disc valve or shaft-distribution motor?

B6K uses disc distribution with a geroler mechanism. The standard catalogue motor has heavy tapered roller bearing support; 6KS is a separate bearingless arrangement.

What is the continuous speed of B6K-310?

It requires confirmation. The summary prints 698 rpm continuous and 485 rpm intermittent, which conflicts with the duty hierarchy and chart. Do not select an operating speed from that disputed entry.

Can maximum torque and speed be used together?

No. The table lists individual limits, not one combined duty point. Provide required torque, rpm, pump flow, pressure, temperature and duty cycle for a checked selection.

How long is intermittent operation allowed?

Up to 6 seconds per minute. Use the displacement-specific continuous ratings for sustained duty, subject to the actual configuration and thermal conditions.

Does every B6K include a brake?

No. 6KB is a separate parking-brake arrangement. The catalogue prohibits dynamic braking; release pressure, holding torque, circuit and installation dimensions require separate confirmation.

Which way does the standard motor rotate?

Viewed facing the output shaft, A inlet and B outlet give clockwise rotation; reversing flow gives counterclockwise rotation. Confirm the ordered R/L code and physical port positions on the drawing.

Does a 6K, BM6 or OMT family name establish interchangeability?

No. Compare the original full number, displacement, shaft, pilot, bolt pattern, ports, seals, case drain, rotation, ratings and load support. Similar family names or nominal sizes are insufficient.

What information is needed for an EXW Hebei quote?

Send the complete model or original part number, drawing or photographs with measurements, operating point, quantity and destination. Sample availability, MOQ, lead time, packaging and any marking requirements are confirmed for the actual order.

Request B6K selection and an EXW Hebei quotation

Send Olive Branch Hydraulics the original motor number or configuration drawing, required working point, quantity and destination. Include sample, marking, packaging or documentation requirements so the quotation can state the agreed configuration, terms and lead time.

For a different disc-valve range, compare the B4K orbital hydraulic motor or B2K disc valve motor using each family’s own specifications and drawings.