In production lines, European‑style jaw crushers typically serve as the primary crusher, and their throughput directly impacts the overall output of the entire line. However, improper operation can lead to a decline in crushing capacity. This issue stems from multiple factors. Today, we’ll examine the causes of sub‑standard throughput in European‑style jaw crushers and explore strategies for boosting productivity.

Reasons for the decline in output of European‑style jaw crushers:

1. Material hardness does not meet specifications.

If the hardness or toughness of the material to be crushed exceeds the range specified in the operating manual, you may replace it with a suitable crusher or add an additional crusher when the required specifications are not met.

2. The motor wiring is connected in reverse.

If the motor wiring is reversed, the main unit will run in reverse (with the moving jaw rotating clockwise), or if the motor’s delta connection has been mistakenly wired as a star connection, adjust the motor wiring accordingly.

3. The discharge opening is smaller than specified.

The output of the European‑style jaw crusher has not met the factory‑specified standards, possibly because the discharge opening is smaller than the prescribed limit. In this case, the discharge opening should be adjusted to the nominal setting specified in the manual, and a crusher designed for fine crushing should be added.

4. Jaw plate displacement

It may be due to jaw plate misalignment, causing the tooth tops to come into direct contact. In this case, immediately check the tooth pitch dimensions; if they do not meet specifications, replace the jaw plate and adjust the relative position of the fixed and moving jaw plates. After ensuring proper alignment between the tooth tops and roots, secure the assembly with clamping bolts to prevent further displacement.

5. Low on-site voltage

If the voltage at the worksite is too low, resulting in the jaw crusher’s output falling short of its factory‑rated capacity, the site voltage should be increased to meet the heavy‑load requirements of the main unit.

6. Relative rotation of the bearing outer ring

When the moving jaw and bearings wear excessively, resulting in excessive clearance, the outer race of the bearing may rotate relative to the housing; in such cases, the bearings or the moving jaw should be replaced.

Methods for increasing the production capacity of jaw crushers:

1. Strictly control the feed size to prevent cavity blockages and clogging.

The design dimension of the feed opening for European‑style jaw crushers follows this formula: Feed opening size = (1.1–1.25) × maximum particle size of the raw material.

Many production personnel do not fully understand this and consistently use the measured feed opening size as the maximum feed size. As a result, oversized particles in the raw material readily become lodged, causing blockages in the crushing chamber. Although such blockages do not occur frequently, each time they do, the equipment remains out of service for an extended period. Therefore, stringent control of raw‑material particle size is one of the most critical prerequisites for ensuring the reliable operation of European‑style jaw crushers.

2. Strictly control the feed rate to prevent blockages caused by overfeeding.

Many enterprises experience severe production disruptions due to insufficient initial feed rates, prompting technical upgrades to their material bins. However, these upgraded bins, lacking devices to regulate feed volume, often give rise to an opposite problem: excessive feeding.

Because the European‑style jaw crusher operates on a semi‑cyclical principle, excessive feed can prevent the material from being crushed in time, and the crushed product may not be discharged promptly, leading to blockages. Consequently, both insufficient feeding and overfeeding will adversely affect the crusher’s production capacity.

3. Use a rhythmic feeding system to control the material supply and ensure the proper operation of the European‑style jaw crusher.

Currently, in the crushing sections of mineral processing plants, end‑feed chutes are commonly used, with two-thirds of the feeding equipment—or even the entire unit—protruding outside the bin. Because the feed inlet is located far from the discharge point, the feeder effectively functions as a vibrating chute, resulting in poor feeding rates and severe wear. The optimal feed location for a feeder is within the upper one-third of the equipment; however, vertical feeding must be strictly avoided to prevent excessive pressure that could impair the equipment’s vibration performance or compromise conveying efficiency.

In particular, when using a dump truck for direct unloading, the drawbacks of vertical feeding become even more pronounced. Therefore, the key to ensuring smooth material discharge without compaction—and aligning the feed rate with both the feeder and the processing capacity of the European‑style jaw crusher—is to properly adjust the angle of the discharge hopper, thereby providing a reliable foundation for consistent feeding.

4. Adjust the feeder angle to fully leverage its screening function and achieve pre-screening.

Vibrating feeders are typically equipped with grates, which provide some screening capability. However, in practical applications, factors such as amplitude and the feed angle often cause oversized material to become lodged between the grate bars, severely compromising the equipment’s intended performance. In response, many companies seal these grates with steel plates, effectively converting the feeder into a plate‑type ore distributor.

In fact, when properly adjusted, the vibrating feeder’s grizzly bars deliver remarkably high efficiency. By fine-tuning the amplitude and the feeder’s angle, you can fully maximize its screening performance—this is the most effective way to boost overall throughput.

5. Properly adjust the discharge opening and jaw angle of the European‑style jaw crusher to maximize the equipment’s processing capacity.

The size of the discharge opening in a European‑style jaw crusher determines the machine’s processing capacity. As European‑style jaw crushers are typically used as primary crushing equipment, the discharge opening should be set according to the optimal feed particle size for the secondary crushing stage; it must not be arbitrarily enlarged or reduced.

The adjustment of the nip angle (the angle between the moving jaw plate and the fixed jaw plate) must be carried out with particular precision, typically within the range of 17° to 26°, with the exact value determined by actual operating conditions.

In addition, the horizontal stroke of the moving jaw, the nip angle of the discharge gap, the rotational speed, and the moisture content of the feed material are also factors that affect the capacity of a jaw crusher. You can increase the crusher’s throughput by adjusting these parameters.