Steering Chain PR-19.05-31.8

Steering Chain PR-19.05-31.8

The PR-19.05-31.8 chain (GOST 13568-97) is a drive roller element of the front travel control system, which is standard equipment on modernized ZM-60U, ZM-90U, ZM-120U series grain loaders and their ZMB hopper modifications (including the classic ZM-60/60A models). In the general kinematic scheme of the frame, it performs the function of a flexible link between the control elements and the actuator, transmitting torque from the small driving sprocket shaft ZP 01.330 to the large driven steering sprocket ZP 01.402 of the front strut.

Structurally, this is a classic single-row drive roller chain with a pitch of 19.05 mm. Its main engineering task is to ensure synchronous and precise turning of the wheel base in response to the operator's steering wheel rotation. The reliability of this transmission depends directly on proper adjustment — thanks to the movable steering support ZP 01.011.3 featured on our new machines, chain tension is controlled by a standard turnbuckle tie rod. This allows for the prompt compensation of natural operational elongation of the links, prevents sagging or slipping off the teeth, and eliminates the "dead" free play (backlash) of the steering wheel when maneuvering a massive unit over threshing floor irregularities.

Technical Specifications of Steering Chain PR-19.05

• Marking: PR-19.05-31.8 (GOST 13568-97)
• Application: ZM-60U, ZM-90U, ZM-120U, ZMB-90U, ZMB-120U, ZM-60, ZM-60A
• Type: Drive roller single-row
• Chain pitch: 19.05 mm
• Quantity per unit: 1 pc.

The operational length of the steering chain is not a universal constant value and depends on the specific modification of the grain loader and the geometry of its frame. In practice, control systems are typically designed for 65, 70, or 75 links, where the difference between them is about 10–20 centimeters. Furthermore, on classic machines of previous production years, the actual center-to-center distance between sprockets is often altered as a result of welding work or modifications to the support struts. Because of this, the chain is usually measured and fitted by the operator directly on-site for the specific unit. To conveniently form the required length, detachable connecting links (master links S-PRL-19.05) are used for closing an even number of pitches, and special offset links (half-links P-PRL-19.05) are used for an odd number — this makes it possible to quickly add or remove chain sections right at the threshing floor to achieve the required size.

Regarding specific sizes: on classic grain loaders, the basic factory length is 65 links (L=1238.25 mm), whereas our standard chain is designed for 70 links (L=1333.5 mm), though extended versions with 75 links (L=1428.75 mm) are also quite common. In this listing, we sell our standard 70-link chain specifically, but upon your request, we can easily adapt it — we will add or remove extra links and include additional connecting or offset links in the package. Therefore, to avoid errors and save time on modifications, we recommend simply counting the number of links on your old chain before placing an order.

To maintain proper chain tension during operation on modernized machines, a movable steering support ZP 01.011.3 is used. Its design, in the form of a guide carriage, allows the steering column to be moved using a screw tie rod. It should be noted that the longitudinal travel of this support is calculated for a small distance and is intended exclusively for routine maintenance — compensating for the natural operational elongation of the metal links. Adjusting the support's position allows you to timely eliminate steering wheel free play (backlash) and prevent chain sagging, although the base number of links during initial installation must still be measured and selected precisely.

Adjacent Steering Drive Parts

Since the chain is a flexible transmission link, its durability and correct operation depend directly on the condition of adjacent steering assemblies. During maintenance of this system, attention should be paid to the following parts:

• Sprocket shaft (ZP 01.330)
• Steering sprocket (ZP 01.402)
• Steering support (ZP 01.011.3)
• Detachable links (S-PRL-19.05 and P-PRL-19.05)

In practice, when repairing classic grain loaders, one often has to deal with the consequences of previous "garage" interventions — re-welding steering support struts with angle deviations, replacing original sprockets with larger ones, or severe wear. All these farm-common modifications directly affect the actual center-to-center distance and transmission geometry. Installing a new chain on old sprockets with deformed or sharpened teeth will cause the link pitch to quickly break down, and the new metal will begin to stretch intensively. In addition, due to the altered geometry of the old frame, you may require a different number of links than specified in the factory standard, which is precisely where spare connecting or offset links will come in handy.

To avoid constant tightening, eliminate steering wheel free play (backlash), and restore correct control kinematics, we recommend replacing worn elements as a single kit. Ordering a new chain together with the driving sprocket shaft ZP 01.330 and the large driven sprocket ZP 01.402 ensures a perfect match between the tooth profile and the link rollers. This approach saves the operator time on repeated unit disassembly and guarantees precise, smooth, and reliable steering operation during intensive machine maneuvers on the threshing floor.

Buy Steering Chain PR-19.05 at Zavod Moroza

Correct kinematics and safe maneuvering of a heavy grain loader begin with a reliable chain drive free of parasitic play. At Zavod Moroza, you can purchase a high-quality PR-19.05-31.8 drive roller chain designed for high alternating loads of the steering assembly.

As a direct manufacturer of equipment, we understand perfectly well that every old frame has its own operational history, and distances between sprockets are often altered by makeshift repairs. Therefore, we offer a flexible approach: you can order our 70-link factory standard, or we can assemble a chain of a different length tailored to your individual parameters (65, 75, or any other number of links). Upon your request, we will certainly supplement the order with the necessary detachable master links (S-PRL) and offset half-links (P-PRL) so that the final fitting process on-site is as quick and convenient as possible.

Contact our sales department for component selection. We are well-versed in the steering mechanisms and other assemblies of grain loaders across different generations and recommend approaching repairs rationally. Order a new chain bundled with the steering sprockets and our modernized movable steering support — restore the correct transmission pitch and guarantee your machine an ideal obedience, effortless steering wheel rotation, and factory-level control precision for years to come!