The jaw crusher is one of the most admired and sought-after pieces of equipment from the supplier Sandreck. To maintain stable output, low downtime, and long service life, equipment operators and maintenance teams must understand professional jaw crusher parts.
A jaw crusher consists of:
| Jaw Plates | Cheek Plates | Eccentric Shaft | Toggle Plate |
| Flywheel | Pitman Assembly | Jaw Crusher Bearings | Setting Adjustment |
| Retraction Spring and Screw Rod | Rear End Frame |
1. Jaw Plates (Crusher Liners)
As the most wear-prone and critical crushing parts, jaw plates are the direct working surfaces that compress material. Consisting of a fixed jaw plate mounted on the frame and a movable jaw plate attached to the pitman, they form the crushing chamber that squeezes hard rocks, ores, and construction aggregates. Made of high-manganese or alloy steel with impact resistance, these parts withstand extreme friction and impact forces during operation. Regular wear inspections are necessary. A reversible jaw plate design can double service life and reduce replacement frequency, effectively cutting operating costs.
2. Cheek Plates (Side Liners)
Cheek plates are installed on both side walls of the crushing chamber and serve as protective jaw crusher wear parts. Manufactured from high-strength manganese steel alloys, they resist severe side friction and impact. For heavy-duty crushing of hard stone, thickened cheek plates are recommended to improve equipment durability and prevent side-wall damage.
3. Eccentric Shaft
The eccentric shaft is the core power-transmission component of the jaw crusher, driving the pitman and movable jaw to create elliptical reciprocating motion for continuous crushing. It adopts high-precision forging steel to withstand huge torque and bending pressure. Supporting the eccentric shaft, heavy-duty roller bearings ensure flexible operation and reduce mechanical friction.
4. Jaw Crusher Bearings
Typically, four bearings support the eccentric shaft: two on each side of the jaw frame and two at each end of the pitman. These bearings are typically roller-in-style and usually have labyrinth seals, and some are lubricated with an oil bath system.
5. Toggle Plate
The toggle plate is both a transmission part and a safety protection component of jaw crushers. It transmits thrust to the movable jaw to complete the crushing movement and automatically breaks when non-crushable materials enter the chamber, protecting the eccentric shaft and other core components from severe damage. The toggle seat supports the toggle plate and stabilizes force transmission.
6. Flywheel
The flywheel stores rotational kinetic energy. During the jaw’s open stroke, the flywheel accumulates energy. During the crushing stroke, it releases energy to smash hard stone. Balanced flywheel weight reduces vibration and stabilizes running status.
7. Pitman Assembly
The pitman is the moving body of the jaw crusher’s crushing mechanism. Driven by the eccentric shaft, it drives the movable jaw to reciprocate and complete material compression, crushing, and discharging. Made of high-strength cast steel, the integral pitman structure effectively resists deformation under high impact force, ensuring a stable crushing stroke and production capacity.
8. Retraction Spring and Screw Rod
The retraction spring and screw rod pull the pitman assembly back after each crushing stroke. Together with the toggle plate, they complete the full movement cycle: squeeze stone, then open cavity for finished material discharge. Loose springs can cause abnormal pitman shaking.
9. Setting Adjustment
Setting Adjustment changes the gap between jaw plates. By adjusting this mechanism, plant managers control final product particle size. When jaw plates wear thin, operators also rely on setting adjustment to compensate for wear and keep the qualified output size.
10. Rear End Frame
It is the heavy‑duty main support structure. All crushing impact load passes to this frame. It requires high casting strength to avoid deformation under long-term heavy‑load work.
For overseas quarry buyers, understanding what a jaw crusher consists of helps you communicate clearly with suppliers when purchasing replacement jaw crusher parts. Sandreck is a Chinese jaw crusher manufacturer. We independently produce jaw crushers and spare parts, offering dual guarantees for production and after‑sales service. If you need replacement jaw crusher spare parts, please contact us.
