DRP BEARINGS AND TRANSMISSION LTD.

Suppliers of bearings, belts,bearings, seals, gearboxes, castors, sprockets, chain, pulleys,loctite, couplings, keysteel,Oilite, du bushes, nipples, taper rollers, gearboxes. needle bearings.
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Castor information.

Mountings.

Top plate – commonest fixing with four bolt holes to spread the load over the swivel head.

Single bolt hole – Limited to loads of up to 320kg having a fastener through the centre of the swivel head. Can be fitted with either threaded stems or round/square expanding sockets to fit in tubes.

Loadings

 The effect of uneven floors due to cracking, joints or gullies must be allowed for when assessing the required load rating of the castor. The degree of such defects will determine the extra shock loads acting on the castors.

Castor configurations. – These will also effect load calculations as, when moving, one or more castors may float on uneven floors removing its share from the loading. An allowance for this must be made, and so the castor load capabilities are listed below, along with the uses and characteristics of each configuration. Click on the drawing number

Drawing 1. Two swivels and two fixed- when pushed with the two fixed castors leading, this offers the best load control with good steering on straight runs and cambers. Suitable for most loads.  Castor capacity at least 33% of total gross load.

Drawing 2. Four swivels – for maximum manoeuvrability. Difficult to control on straight runs, cambers and uneven surfaces, particularly with heavy loads- to overcome this fit directional locks. Castor capacity at least 33% of total gross load.

Drawing 3. One swivel and two fixed- For easy manoeuvrability. Suitable only for small trolleys with light loads.  Stability can be a problem so loads must be distributed evenly. Castor capacity at least 40% of total gross load.

Drawing 4. Three swivel- for maximum manoeuvrability. Can be difficult to control on straight runs, cambers and uneven surfaces. Suitable only for small trolleys with light loads, Castor capacity at least 40% of total gross load.

Drawing 5. Four swivel and two fixed, centrally pivoting-Usually used on long trolleys to optimise control and manoeuvrability. The two central fixed castors are usually one size larger, or the same size as the swivels and fitted with 25mm packing under the top plate.  Castor capacity for the fixed castors at least 50% of the total gross load. Swivel castors loads will vary.

Drawing 6. Two swivel and two fixed, centrally pivoting. Similar to drawing 5 above but less stable if the load is not evenly distributed. The two central fixed castors are usually one size larger, or the same size as the swivels and fitted with 25mm packing under the top plate.  Castor capacity for the fixed castors at least 50% of the total gross load. Swivel castor loads will vary.

Wheels

Castor wheels are designed to be supported on both side and intended for use on units with manual propulsion of up to 4mph. The extra stresses of powered towing should only be considered with specialist advice. Wheels are categorised into two groups – hard tread and soft tread.

Hard tread wheels. –  the easiest to push as they have least tractive resistance. The main disadvantage is that is that they are noisy and can wear floors excessively. The main types are as follows…

Cast iron and steel – combine shock resistance  with long life and economy. Temp range -40c to +300c

Nylon – has high load capacity, is light and clean and causes little floor damage. Temp range -40c to +80c

Polypropylene – Has good load capacity but not the abrasion or fracture resistance of nylon. Operational temp range is -20c to +80c.

Phenolic  - very hard, abrasion and fracture resistant but liable to wear and chipping. High operational temp range up to +300c.

Soft tread wheels. – are resilient generally resulting in less noise, marking and floor wear.Tractive resistance is however much higher. New development grade of polyurethane and rubber have increased load capacities while reducing tractive resistance…

Solid rubber – the basic wheel, although new thermoplastic grades are harder wearing and low cost. Temp range -20c to +60c

Elastic rubber – has a high load capacity and wear resistance with a smooth soft-cushioned ride. Temp range -20c to +60c

Polyurethane – has a very high load capacity with abrasion, tear and chemical resistance coupled with a soft ride.

Pneumatic – Has excellent shock absorption working well on rough, uneven surface like grass or gravel. Temp range -20c to +250c

High temperature – Wheels now available with rubber tyres suitable for use in the temperature range -30c to+250c

Nylon wheels.


Nylon wheeled castor with galvanised brackets. Available in sizes below from stock (dependant on sales): Other sizes and variations available on request.

50mm,

63mm 90x27 bolt centre mounting 85kg load per wheel.

75mm

80mm with 80x60 bolt centre mounting. 150kg load per wheel.

100mm with 80x60 270kg or 105x80 270kg or 80x60 150kg bolt centre mounting.

125mm with 80x60 300kg or 105x80 300kg or 80x60 200kg bolt centre mounting

150mm with 105x80 350kg bolt centre mounting.

Figures in red indicate wheel load rating.

Other sizes and variations available on request.

Nylon with Red polyurethane tyre

Nylon inner with red polyurethane outer tyre stainless steel (304) brackets.  Available in sizes below from stock in either swivel, fixed or swivel and braked.

In red or Maroon tyre.

Other sizes and variations available on request.

80mm with 80x60 bolt centre mounting load 150kg

100mm with 80x60 bolt centre mounting load 150kg

125mm with 80x60 bolt centre mounting load 200kg

150mm with 80x60 bolt centre mounting load 250kg

150mm with 105x80 bolt centre mounting load 340kg

Figures in red indicate wheel load rating.

Grey or black rubber

Polypropylene inner on grey or black  rubber tyre with galvanised brackets.  Available in sizes below from stock in either swivel, fixed or swivel and braked

Other sizes and variations available on request.

50mm with hole centres 43x43mm  Load 40kg grey

75mm with hole centres 48x48mm load 70kg grey

80mm with hole centres 80x60mm load 50kg grey

100mm with hole centres 80X60MM Load 70kg grey

125mm with hole centres 80x60mm load 90kg grey

160mm with hole centres 105x80/75mm load 140kg black

200mm with hole centres 105x80/75mm load 205kg black

Figures in red indicate max wheel load.

Bolt hole castors

Nylon inner with red polyurethane outer tyre. Stainless steel (304) or galvanised with bolt hole fixing . Available in sizes below from stock in either swivel, fixed or swivel and braked

Other sizes and variations available on request.

80mm with 12mm bolt hole fixing.  Galvanised or Stainless steel.

100mm with 12mm bolt hole fixing.  Galvanised or Stainless steel.

125mm with 12mm bolt hole fixing.  Galvanised.


Nylon wheeled castor bolt hole design in galvanised or stainless steel. Available in sizes below from stock in either swivel or swivel and braked  

Other sizes and variations available on request.

80mm with 12mm bolt hole fixing.  Galvanised or Stainless steel.

100mm with 12mm bolt hole fixing.  Galvanised or Stainless steel.

125mm with 12mm bolt hole fixing.  Galvanised.


Polypropylene inner on grey rubber tyre, galvanised with bolt hole fixings.  Available in sizes below from stock in either swivel, fixed or swivel and braked.

Other sizes and variations available on request.

50mm with 10mm bolt hole.

80mm with 12mm bolt hole.

100mm with 12mm bolt hole.

125mm with 12mm bolt hole.