The most important operating condition determining cone crusher performance is that material enters the crushing chamber evenly and centrally. This job is done by the feed plate at the very top of the head and the distributor in the feed area. While distributing falling material through 360°, the feed plate also protects the head nut and the top of the head from direct impact.
Although it looks like a small, inexpensive part, a worn feed plate can cause uneven liner wear, ring bounce, damage to the head nut and poor product quality. In this guide we cover the function of the feed plate and distributor, the importance of the feed arrangement, signs of wear, replacement steps and spare part selection. For general cone crusher operation, see our cone crusher guide.
Function of the Feed Plate and Distributor
- Distributes the material: Directs material falling in the centre evenly around the crushing chamber.
- Protects the head nut: Prevents impact and wear from reaching the head nut and the top surface of the head.
- Helps keep the chamber full: Correct distribution ensures that the whole chamber is used.
- Reduces segregation: Limits coarse and fine particles collecting on different sides of the chamber.
The Importance of Even Feeding
When more material falls on one side of the chamber:
- The mantle and concave on that side wear faster; liners are replaced before reaching their full life,
- The bowl is loaded unevenly and the risk of ring bounce increases,
- Product size and particle shape fluctuate,
- Motor power usage becomes unbalanced.
Therefore, in addition to the feed plate, the feed box, the discharge point of the feed conveyor and the deflector plates should be assessed together. The feed conveyor should be positioned to drop material exactly in the centre of the crusher.
Signs of Wear and Failure
- Thinning, holes or broken edges on the feed plate,
- Wear marks on the head nut and top of the head,
- One-sided wear on the liners,
- Irregular chamber filling and ring bounce,
- Loose feed plate fasteners.
Inspection and Maintenance
| Check | Interval | Method |
|---|---|---|
| Visual check of the feed plate | Weekly | From above, under LOTO |
| Fasteners | Weekly | Check for loosening and breakage |
| Feed point and deflectors | Weekly | Conveyor discharge point and wear |
| Liner wear profile | At liner change | Is there one-sided wear? |
Replacement Steps
- The crusher and feeder are stopped, LOTO is applied and the chamber is emptied.
- The feed box or top cover is removed if necessary for access to the plate.
- Feed plate fasteners are removed; the plate is lifted out with a lifting device.
- The head nut and top surface of the head are checked.
- The new plate is installed centred and the fasteners are tightened to the manufacturer’s torque.
- The feed point and deflectors are checked and corrected if necessary.
As a practical rule, the feed plate should be replaced every time the mantle is replaced. For details, see our mantle and concave replacement guide.
Common Mistakes
- Running with a holed plate: The head nut wears directly.
- Not checking the feed point: A new plate cannot solve an uneven feed problem either.
- Neglecting fasteners: A loose plate can fall into the chamber.
- Incompatible plate: Centring and seating problems.
Troubleshooting Table
| Symptom | Possible cause | Solution |
|---|---|---|
| Liners wearing on one side | Off-centre feeding, worn plate | Correct the feed point, replace the plate |
| Head nut worn | Plate holed or missing | Replace the plate immediately and check the nut |
| Ring bounce | Uneven distribution, segregation | Improve the distributor and feed arrangement |
| Plate wears quickly | High drop height, abrasive material | Reduce the drop height, review the material |
An Example from the Field
At one plant, the concave of a cone crusher was wearing much faster on one side and liner sets were being replaced at half their planned life. It was found that the feed conveyor approached the crusher at an angle and material was falling on the edge of the feed plate rather than on it. A deflector and distributor were added to the feed box and the feed plate was renewed. The wear profile was balanced, liner life increased considerably and ring bounce alarms decreased.
Spare Part Selection
- Material: Impact- and wear-resistant manganese or wear-resistant steel.
- Dimensions and fixing: Compatibility with the head nut and fixing points.
- Distributor and feed box parts: Should be selected according to the feed arrangement.
CSP Mühendislik supplies feed plates, distributors and feed box wear parts as part of its cone crusher spare parts range. We recommend assessing the condition of the head nut and mantle and concave in the same shutdown.
Pre-Purchase Checklist
- Have the crusher model and feed plate part number been identified?
- Has it been scheduled for the same shutdown as the mantle change?
- Have fasteners been added to the order?
- Has the condition of the feed box and deflectors been assessed?
Frequently Asked Questions
When should the feed plate be replaced?
At every mantle change, or when holes, marked thinning or breakage appear on the plate.
Can the crusher run without a feed plate?
No. The head nut and top of the head are left unprotected and distribution is disturbed.
Does every crusher have a distributor?
It depends on the design; in some crushers rotating or fixed distributors are part of the feed box.
How is the feed point corrected?
By adjusting the discharge point of the feed conveyor, the chute design and deflector plates so that material falls in the centre of the crusher.
Feed Box and Distributor Arrangements
The feed arrangement above a cone crusher determines how efficiently the crusher will work. Common arrangements are:
| Arrangement | Description | Advantage |
|---|---|---|
| Fixed feed box | The conveyor discharges directly into the box | Simple; sufficient if the feed point is set well |
| Box with distributor plates | Deflector plates inside the box | Reduces segregation and one-sided feeding |
| Rotating distributor | Spreads material around by rotating | Very even distribution |
| Level-controlled surge bin + feeder | Material stock above the crusher | Choke feeding and stable operation |
Setting the Feed Point
- If the feed conveyor approaches the crusher at a steep angle, material is thrown forward in the direction of belt travel and falls on the opposite side of the crusher; in this case an impact plate or deflector should be used in the feed box.
- If belt speed is high, the throw distance increases; the deflector position should be adjusted accordingly.
- To prevent coarse and fine particles separating, keep the material mixed on the belt and make it fall at a single point in the box.
Effect of Operating Conditions on Feed Plate Life
| Condition | Effect | Recommendation |
|---|---|---|
| High drop height | Increased impact wear | Create a material bed with a surge bin |
| Coarse feed | The plate is deformed by impact | Keep feed size suited to the crushing chamber |
| Abrasive material | The plate thins quickly | Inspect more often, use durable material |
| Feeding an empty crusher | The plate takes direct impact | Ensure choke feeding |
Maintenance Record Form
| Field | Record |
|---|---|
| Plate condition | Thickness, holes, breakage |
| Head nut condition | Any wear marks? |
| Liner wear profile | Even / one-sided |
| Feed point | Adjustments made |
OEM or Aftermarket?
The feed plate must match the head nut and the top surface of the head exactly. When choosing an aftermarket plate, fixing points, centring geometry, thickness and material should be documented. A plate that does not seat correctly does not fully protect the head nut and can loosen with vibration.
Stock Planning
- Keep one feed plate in stock for each mantle change.
- Fasteners and any protective caps should be stocked together with the plate.
- Make a separate stock plan for feed box wear liners.
More Questions
Does a surge bin extend feed plate life?
Yes. A surge bin with level control that creates a material bed above the crusher reduces direct impact of falling material on the plate and ensures choke feeding.
Does feed plate wear affect the CSS?
Not directly; but by disturbing distribution it causes uneven liner wear and product fluctuation.
Does the crusher have to be dismantled to replace the plate?
In most designs the plate can be reached by removing the feed box; during mantle changes the plate is removed anyway.
Spare Parts and Service for Feed Plates
CSP Mühendislik supplies cone crusher feed arrangement and wear parts as part of its cone crusher spare parts range, and supports feed point optimisation and liner changes with our service team. Send your crusher model on WhatsApp for a quick quote.
