DI-SAN DS322 and DS323 Gearboxes for Corn Headers

A corn header driveline combines mechanisms with different speed and torque requirements. Some units require a comparatively high rotational speed, while others need substantial driving force at lower rpm. These operating conditions are created by bevel gearboxes with specific gear ratios and shaft configurations.

The DI-SAN DS322 and DS323 are designed for corn header drivelines. Both models can transmit up to 45 kW, but they perform different functions: the DS322 increases rotational speed, while the DS323 reduces speed and increases torque.

How a Corn Header Driveline Works

The working mechanisms of a corn header must operate synchronously. Row dividers guide the stalks into the rows, gathering chains move the plants, snapping rolls separate the ears, and the auger collects the crop and feeds it towards the combine feeder house. Headers equipped with chopping systems add another heavily loaded mechanism to the driveline.

Power is transmitted between these units through a system of shafts, chain drives and gearboxes. Bevel gears change the direction of power flow and transmit rotation between intersecting shafts. The ratio of each gearbox is selected according to the speed required at a particular point in the driveline.

The DS322 and DS323 have multi-shaft arrangements with three bevel gears. This configuration allows rotation to be transmitted in several directions and makes the gearboxes suitable for distributed corn header drivelines.

DI-SAN DS322 and DS323 Comparison

The same permissible power rating does not make these models interchangeable. Their different ratios produce opposite operating characteristics and substantially affect the speed, load and kinematics of the driven mechanism.

DI-SAN DS322: Increasing Rotational Speed

The DS322 operates with a 1:1.60 gear ratio. At an input speed of 750 rpm, its output shafts reach 1,200 rpm. The output torque is 345 Nm.

This operating mode is used in driveline sections that require a higher rotational speed. The bevel gear arrangement changes the direction of power flow while increasing the speed by a factor of 1.6.

The DS322 is rated for an input power of up to 45 kW. A 1⅜-inch Z6 six-spline shaft connects the gearbox to the driveline. Its design provides several directions of power transmission, while shaft dimension L can be selected for a particular machine configuration.

The DI-SAN DS322 gearbox can be ordered and purchased from the BAS website. Before ordering, the gear ratio, shaft configuration and mounting dimensions should be checked against the corn header specifications.

DI-SAN DS323: Reducing Speed and Increasing Torque

The DS323 is a speed-reducing gearbox. At an input speed of 1,200 rpm, its 2.07:1 ratio produces an output speed of 579 rpm. At the same time, the output torque increases to 715 Nm.

This combination of speed and torque is suitable for heavily loaded mechanisms that require substantial driving force at a moderate rotational speed. The DS323 provides more than twice the torque of the DS322, although both models have the same input power rating.

The gearbox uses a 50 × 45 spline connection manufactured to DIN 5482. As with the DS322, shaft dimension L can be produced according to the requirements of a specific driveline.

The DI-SAN DS323 gearbox is also available to order and purchase from the BAS website. Accurate selection requires consideration of the header model, gearbox position in the driveline, direction of rotation and connecting dimensions.

Kinematic Relationship Between the DS322 and DS323

The gearbox characteristics are kinematically aligned: the DS322 output speed is 1,200 rpm, which is also the nominal DS323 input speed. This allows the models to be used at speed-matched points within a distributed driveline.

Their actual positions depend on the design of the corn header. The DS322 and DS323 should not automatically be assumed to operate directly in sequence. Intermediate shafts, chain drives, safety clutches and other transmission components may be installed between them.

The calculated output power of the two models is also similar. The DS322 combination of 345 Nm and 1,200 rpm, as well as the DS323 combination of 715 Nm and 579 rpm, corresponds to approximately 43.3 kW at the output. The small difference from the rated input power of 45 kW is associated with gear-mesh losses and the rounding of published specifications.

Why the DS322 and DS323 Cannot Be Interchanged

Installing a gearbox with the wrong ratio changes the operating conditions of the entire connected mechanism. If the speed-increasing DS322 is installed in place of the speed-reducing DS323, the resulting output speed will be significantly higher than required. This can accelerate wear of chains, bearings, shafts and working components.

The reverse substitution also disrupts the driveline kinematics. The mechanism will receive insufficient speed, while the load distribution between header components will change. Possible consequences include unstable stalk feeding, accumulation of crop material and transmission overload.

The two models also differ in spline design and mounting geometry. Even when gearbox housings appear similar, selection must be based on the complete set of technical parameters.

Gearbox Input Speed and PTO Speed

The values of 750 and 1,200 rpm refer to the input shafts of the gearboxes themselves. They should not be equated directly with the power take-off speed of a tractor or combine.

Before reaching the gearbox, rotation may pass through an intermediate transmission that has already changed the speed. Selection must therefore be based on the rotational speed at the actual DS322 or DS323 installation point. Relying only on standard PTO speeds of 540 or 1,000 rpm can result in an incorrect choice.

The specified values of 1,200 and 579 rpm are also gearbox output-shaft speeds. The actual rotational speed of the gathering chains, rolls, auger or another working mechanism depends on any subsequent transmission stages.

What to Check Before Ordering

When replacing a gearbox, compare:

1. the marking of the removed unit;
2. the gearbox application and position in the driveline;
3. the gear ratio;
4. the required input and output speeds;
5. the direction of shaft rotation;
6. the permissible power and torque;
7. the number and arrangement of shafts;
8. the spline types and dimensions;
9. the shaft lengths;
10. the mounting dimensions and bolt-hole positions.

If the original gearbox marking is damaged, accurate selection will require photographs of the housing, shafts, mounting points and installation location. Dimensions should be measured from cleaned mating surfaces because dirt and deformation can distort the results.

Loads and Causes of Premature Wear

A corn header driveline operates under variable loads. Crop flow changes constantly, while dense stalks or foreign objects can cause short-term torque spikes.

Common causes of gearbox damage include blocked working mechanisms, incorrect rotational speed, misaligned connecting shafts, worn splines and operation with insufficient oil. Loose mountings create additional vibration, accelerating bearing wear and interfering with seal performance.

The safety clutch must operate before the load reaches a level that could damage the transmission. Replacing this clutch with a rigid connection transfers impact loads directly to the gears, shafts and bearings.

Noise, increased housing temperature, excessive play or oil traces require the driveline to be stopped and inspected. Continued operation under these conditions can damage the gear teeth and connected header components.

Lubrication and Maintenance

The DS322 and DS323 use SAE 90 or SAE 140 transmission oil. Each model has an oil capacity of 1.50 litres.

Before the harvesting season, check the oil level, housing integrity, seals and shaft play. Spline connections, gearbox mounting and intermediate-shaft alignment also require careful inspection.

Service intervals are determined by the maintenance schedule of the particular corn header and its operating conditions. After prolonged storage, the gearbox should be inspected before start-up, and the first minutes of operation should be completed without a sudden increase in load. This makes it possible to detect unusual noise, vibration or oil leakage promptly.

Selecting a Gearbox for a Corn Header

The DI-SAN DS322 and DS323 are intended for different driveline sections. The DS322 increases speed from 750 to 1,200 rpm and provides 345 Nm of torque. The DS323 reduces speed from 1,200 to 579 rpm and delivers an output torque of 715 Nm.

The correct choice depends on the header’s kinematic arrangement, required gear ratio, shaft configuration and mounting geometry. Both gearboxes can be ordered and purchased from the BAS website. To verify compatibility, provide the corn header model, the designation of the original gearbox, photographs of the installation position and the principal connecting dimensions.