DI-SAN DS200 and DS201 Gearboxes for Disc Mowers

The DS200 and DS201 gearboxes are designed for rotary disc mower drives, but they establish entirely different speed ranges. The DS200 reduces rotational speed from 540 to 293 rpm, while the DS201 increases it from 1,080 to 2,225 rpm. This difference determines the position of each unit within the machine’s driveline and makes the two models non-interchangeable.

A disc mower operates with high-speed cutting components. Several horizontally arranged discs rotate inside or above the cutterbar, while the knives attached to them cut the crop. Power is transmitted through PTO shafts, right-angle drives and the internal cutterbar transmission. Every component in this system must operate at the specified speed and transmit torque in the correct direction.

How a Disc Mower Differs from a Mower-Shredder

DI-SAN classifies disc mowers as a separate machinery category. The DS200 and DS201 are intended for these machines. The previously reviewed DS205 and DS206 gearboxes are designed for rotary mower-shredders.

A disc mower uses a cutterbar with several rotating discs. A mower-shredder typically has one or more large rotors or blade carriers designed to cut and shred vegetation. Differences in working-unit design produce different requirements for rotational speed, power, torque and driveline configuration.

A rotary mower-shredder gearbox therefore cannot be selected as a replacement for a disc mower gearbox solely on the basis of power rating or housing appearance.

Specifications of the DI-SAN DS200 and DS201

Their shared application does not make these models similar in performance. The DS200 operates as a reduction gearbox with comparatively high output torque. The DS201 is a speed-increasing right-angle gearbox designed for higher power and a high output speed.

DI-SAN DS200: Speed Reduction and Increased Torque

The DS200 has a gear ratio of 1.84:1. With 540 rpm applied to the input shaft, the gearbox produces an output speed of 293 rpm. Output torque reaches 348 Nm.

The model is rated for an input power of 15 hp, or 11 kW. Its internal arrangement consists of three bevel gears. This configuration transfers power between the shafts according to the disc mower’s driveline layout while simultaneously reducing rotational speed.

The input connection uses the common agricultural size of 1⅜″ Z6. Matching splines confirm only that the shafts can be connected. The output shaft, direction of rotation, housing position and mounting geometry must also be checked before installation.

The DS200 requires 0.50 litres of oil and weighs 15 kg. Specifications, pricing and ordering terms are available on the DI-SAN DS200 gearbox page.

The output value of 293 rpm applies to the gearbox shaft itself. The mower-disc speed may differ if another gear, belt or other transmission stage is installed after the DS200.

DI-SAN DS201: Increasing Speed to 2,225 rpm

The DS201 operates as a speed-increasing gearbox. Its 1:2.06 gear ratio raises the speed from 1,080 rpm at the input to 2,225 rpm at the output.

Input power is rated at 45 hp, or 34 kW. This is more than three times the DS200 rating. Output torque is 140 Nm.

The lower torque value does not mean that the DS201 is designed for a less demanding drive. Power depends on both torque and angular velocity. The DS201 transmits substantially more power at a higher rotational speed, so its output torque is lower than that of the reduction-type DS200.

The gear arrangement consists of one pair of bevel gears. The transmission changes the direction of power flow and increases the speed. The input shaft has a 1⅜″ Z6 six-spline connection. Oil capacity is 1 litre, and the gearbox weighs 23 kg.

The input speed of 1,080 rpm requires particular attention. This speed must be supplied directly to the DS201 input shaft. Connecting the model to a 540 rpm drive will not produce the specified output speed of 2,225 rpm. The required 1,080 rpm must be established by the preceding transmission stage in the particular mower.

The value of 2,225 rpm also applies to the gearbox output shaft. It can only be treated as the exact mower-disc speed when no additional transmission stage is installed between the DS201 and the cutting unit.

Specifications, pricing and ordering terms are available on the DI-SAN DS201 gearbox page.

Why the DS200 and DS201 Cannot Be Interchanged

The DS200 and DS201 differ in their overall operating principles, not merely in individual specifications. The first gearbox reduces speed, while the second increases it. Their input speeds differ by a factor of two, and their output speeds differ by more than seven times.

Installing the DS201 in place of the DS200 would radically alter the operating speed of the driven mechanism. The reverse substitution would reduce the speed so substantially that the working unit could not operate in its designed mode. The transmitted torque and loads acting on subsequent driveline components would also change.

The models have different internal designs, housing dimensions and mounting geometry. The DS200 uses three bevel gears, while the DS201 contains one bevel-gear pair. Their weights differ by 8 kg, and the required oil capacities differ by a factor of two.

Searching for a replacement using only the general phrase “disc mower gearbox” cannot confirm compatibility. The model specified for the machine and its function within the driveline must be identified.

What to Check Before Ordering

Accurate gearbox selection requires the mower make and model, the designation of the original unit and its position within the driveline. If the identification marking is damaged, photographs of the housing, shafts and mounting points should be provided together with the principal dimensions.

The following parameters must be compared:

1. Gear ratio.
2. Input and output speeds.
3. Permissible power.
4. Output torque.
5. Direction of shaft rotation.
6. Relative positions of the input and output.
7. Type and dimensions of the spline connections.
8. Output-shaft design.
9. Distances between mounting holes.
10. Installation position of the housing.
11. Presence of subsequent transmission stages.
12. Operating arrangement of the PTO driveline.

Selecting a gearbox solely by its 1⅜″ Z6 input is particularly risky. The same spline connection is used on many agricultural transmissions and provides no information about speed, power or mounting compatibility.

Loads Acting on a Disc Mower Gearbox

The cutting discs operate at high rotational speed. When a knife strikes a stone, metal object or another solid obstacle, an impact load travels through the shaft and gears. The brief torque peak can considerably exceed the load produced during uniform grass cutting.

Additional vibration occurs when bent, damaged or unevenly weighted knives are installed. Imbalance affects the bearings and seals, loosens mountings, increases noise and accelerates gear-tooth wear.

Gearbox damage can also result from a cutterbar blocked by crop material, incorrect input speed, abrupt engagement under load, PTO shaft misalignment or operation with worn joints.

Operation should be stopped if knocking, continuous humming, pronounced vibration, shaft play, oil leakage or unusually rapid housing heating appears. Continuing to mow under these conditions increases the extent of the subsequent repair.

Lubrication and Maintenance

The DS200 and DS201 use SAE 90 or SAE 140 oil. Their nominal capacities are:

• DS200 - 0.50 litres;
• DS201 - 1.00 litre.

The oil level must be checked with the gearbox in its installed operating position. Insufficient lubricant impairs heat dissipation and the formation of an oil film between the gear teeth. Overfilling increases internal pressure and can cause leakage through the seals.

Before the season begins, inspect the housing for leakage, check shaft play and examine the splines, mounting connections and PTO driveline. The cutting discs and knives should be inspected at the same time because a defect in the working unit quickly affects the condition of the entire drive.

Engage the drive at a low engine speed and then bring it gradually to the required operating speed. This procedure reduces impact loads on the universal joints, shafts, gears and bearings.

DI-SAN Disc Mower Gearboxes from BAS

BAS supplies DI-SAN gearboxes for agricultural machinery and helps verify compatibility using technical specifications and connection dimensions. Accurate selection requires the mower model, the marking of the original gearbox and photographs of the installation points.

The DS200 and DS201 perform different functions within a disc mower driveline. The DS200 reduces the speed to 293 rpm and provides 348 Nm of torque, while the DS201 increases the speed to 2,225 rpm and is rated to transmit 34 kW. The correct choice depends on the driveline of the particular machine, shaft arrangement and precise correspondence with the mounting drawing.