This range of quarter turn worm gearboxes is intended for the operation of ball, butterfly, plug and any other ¼ turn valves. It is well suited for applications in power, waterworks and gas pipelines, HVAC, fire protection and most general industrial applications.
They are designed for manual, direct or second reduction operation or motorised operation in combination with electric actuators. In these gearboxes the input and output shafts form a 90° angle.
The function of these gearboxes is to transform a low torque at the input of the gearbox and to achieve a high torque at the output (high transmission ratios), in order to drive a mechanism with possible moderate shocks during its operation. They can only be used in those valves that require turning torque without thrust.
Self-locking. This mechanism is non-reversible, i.e., it is the worm gear that moves the worm wheel, while the wheel cannot move the worm.
Improvements
This new range was designed above all to enhance its quality, reliability and performance applying finite elements calculations through the design phase.
Lightweight design. Minimising non-structural mass.
Greater interchangeability between the different gearbox options, with handwheel, second reduction and motorised to improve and maintain a competitive delivery time.
High performance gears to increase torque not size.
This range is compact in size to facilitate installation as far as possible
To define a competitive relationship between output torque and total weight of the finished product. The challenge was to achieve a factor (>11).
Define an input torque, as low as possible, to facilitate the opening and closing operation. The force applied to the handwheel, for this operation, usually requires 35 kg.
Options
- Padlocking device
- Anti-corrosion coated shafts
- Various handwheel types and sizes
- Symmetrical, can be assembled with the worm shaft on one side or the other side
Technical details
- Housing and cover in cast iron (grey)
- Worm in carbon steel
- Stroke 0 – 90º (adjustable stops at ±5 degrees at each end)
- Insert valve stem options
- Valve coupling applicable standard is ISO 5211
The gearbox has been designed for an input speed of 12 rpm.
This type of gearbox is used exclusively on crossed shafts, between 45º and 97º, in our case 90º. The efficiency is reduced as the transmission ratio increases.
The average working temperature can be estimated in the range of -20ºC to +120ºC.
Weatherproof in accordance with standard IP67
To reduce radial friction on the worm shaft, sintered bronze bushes are used.
To reduce axial friction on the worm shaft, ball bearings are used.
The efficiency of this transmission stage is 35%.
The actuators are lubricated with permanent grease
They are coated acc. to UNE–EN ISO 12944-6 with a total thickness of 230µ that allow them stand under marine C5 atmosphere
They can be used in all installation positions. The technically most favourable and thus recommended installation position is when the worm shaft is horizontal and located at the bottom
Customer drive. As standard, the worm gearboxes are delivered with right-handed worm shafts rotational direction. In the special design, delivery with left-handed gear teeth is also possible.
Second reduction
This type of gearing, used between parallel shafts, has a transmission ratio of 1 : 4.
The efficiency of each transmission stage is 94%. Considering straight teeth.