Wednesday 20th Nov, 2019

Reducing conveyor impact zone problems with impact beds

Thomas Greaves, General Manager of DYNA Engineering, discusses conveyor impact beds: what they are, how they work and why they can increase productivity and reduce maintenance costs.

Thomas Greaves, General Manager of DYNA Engineering, discusses conveyor impact beds: what they are, how they work and why they can increase productivity and reduce maintenance costs.

In a standard conveyor arrangement, a top conveyor feeds material onto a conveyor below by dropping it onto an impact zone.

Often, impact rollers and frames are installed at this point to absorb the impact forces created by the falling material, which can help protect the bottom conveyor belt from damage.

Impact idler rollers and frames are built to handle small, crushed and granular material to improve the longevity of the roller bearings and mechanical joints.

However, if the forces become greater, impact idlers typically suffer premature bearing failure or excessive loading of the connection between the roller shaft and frame. This results in a bearing stress failure on the bottom of the shaft and mating surface of the frame slot.

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In addition, extreme wear and tear can occur if the crushing process doesn’t reduce oversized material from entering the chute, limit the amount of fugitive material, such as bucket teeth and pins, or has a significant fall height.

Because impact rollers and frames are often fitted in areas that will often get damaged or wear quickly, they can potentially break under constant and heavy impact. In such situations, impact beds should be considered as a replacement as they have a higher impact rating than impact rollers and a longer service life.

What exactly is a conveyor impact bed?

An impact bed is a piece of equipment used on conveyor systems to help the belt and structure absorb impact damage caused by large rocks and fugitive material.

Designed to absorb high-impact forces, an impact bed also helps eliminate spillage and scattering of material, increasing productivity and lowering clean-up costs.

Typically located under a conveyor belt at the base of a chute, conveyor impact beds use shock absorbent bars and a strong support frame to reduce shock transfer and are often fitted in place of impact rollers to eliminate damage to impact-roller bearings and other moving parts.

How do they compare to impact rollers?

If a conveyor system is wearing through impact idlers too quickly, or they are just outright breaking, an impact bed might be the answer. Impact beds are a cost-effective way to minimise replacement of damaged impact idler rollers and frames. They can be designed to fit almost any position. Ideally, they should be considered during the design of your conveyor system.

When compared to impact beds, impact rollers have more limitations on impact rating and service life, as impact idler frames cannot be produced to absorb the same amount of energy as impact beds.

In high-impact zones, impact beds will usually last much longer. Another added advantage is the minimal gap between the impact bars which helps to prevent conveyor belt deflection and denting.

Types of impact beds

A standard impact bed is suitable for most applications. Heavy-duty impact beds are constructed from heavy gauge material to withstand the impact from oversized, large and heavy products. This design incorporates a fully welded, heavy-gauge steel plate frame, large diameter pins and highly absorbent impact bars.

Hybrid impact beds incorporate impact rollers in the design. This allows the use of impact rollers, but adds additional support from the side bars. The design offers a greater level of control along the edge of the belt, which assists in maintaining the seal between the skirting rubber and the conveyor belt. It also helps reduce belt sag and movement associated with load shifts.

Custom impact beds can also be designed and manufactured to suit any application.

DYNA Engineering Impact Beds: Modular
Pin-Lock System

One of the unique features of DYNA-TRAC impact beds is a modular pin-lock system, engineered to make replacing worn bars easy. Pins can be unclipped and removed to replace worn impact bars while the sides of the impact bed can be lowered to a horizontal position.

Lowering the sides of the impact bed allows it to slide out from under the belt. The pins can be removed without tools and the bars can be replaced without removing the bed from the conveyor or raising the belt.

Key DYNA-TRAC advantages of impact beds

  Unique construction methods result in a stronger, easily serviceable support frame

  Superior ultra-high-molecular-weight polyethylene-topped impact bars minimise belt wear

  Individually designed to match the adjacent idlers, improving skirt sealing

  Available in three standard heights: 51 millimetres, 76 millimetres and 100 millimetres and can be up to 1500 millimetres long

  Can be serviced from either side of the conveyor 

  All sections are fully welded and galvanised.