Helical Gear Reducer

Worm gears are usually used when large velocity reductions are needed. The decrease ratio is determined by the number of starts of the worm and number of the teeth on the worm equipment. But worm gears have sliding contact which is tranquil but will produce heat and also have relatively low transmitting efficiency.
As for the materials for creation, in general, worm is constructed of hard metal as the worm gear is made from relatively soft metallic such as aluminum bronze. That is since the number of tooth on the worm equipment is relatively high in comparison to worm with its number of begins being generally 1 to 4, by reducing the worm equipment hardness, the friction on the worm the teeth is reduced. Another feature of worm manufacturing may be the need of specialized machine for gear trimming and tooth grinding of worms. The worm equipment, on the other hand, may be made with the hobbing machine used for spur gears. But due to the various tooth shape, it isn’t possible to cut a number of gears at once by stacking the gear blanks as can be done with spur gears.
The applications for worm gears include equipment boxes, angling pole reels, guitar string tuning pegs, and in which a delicate speed adjustment by utilizing a huge speed reduction is necessary. When you can rotate the worm equipment by worm, it is generally extremely hard to rotate worm by using the worm gear. This is called the personal locking feature. The self locking feature cannot continually be assured and a separate method is preferred for true positive reverse prevention.
Also there is duplex worm gear type. When using these, you’ll be able to adjust backlash, as when one’s teeth use necessitates backlash adjustment, without needing a alter in the guts distance. There are not too many producers who can produce this type of worm.
The worm gear is more commonly called worm wheel in China.
A worm equipment is a gear comprising a shaft with a spiral thread that engages with and drives a toothed wheel. Worm gears are an old style of gear, and a version of 1 of the six basic machines. Basically, a worm gear is certainly a screw butted against what looks like a standard spur gear with slightly angled and curved the teeth.
It adjustments the rotational motion by 90 degrees, and the plane of motion also changes because of the placement of the worm upon the worm wheel (or just “the wheel”). They are typically comprised of a metal worm and a brass wheel.
Worm Gear
Figure 1. Worm equipment. Most worms (however, not all) are at underneath.
How Worm Gears Work
An electric electric motor or engine applies rotational power via to the worm. The worm rotates against the wheel, and the screw encounter pushes on the teeth of the wheel. The wheel can be pushed against the load.
Worm Gear Uses
There are a few reasons why you might select a worm gear over a standard gear.
The first one may be the high reduction ratio. A worm equipment can have an enormous reduction ratio with little effort – all one should do is certainly add circumference to the wheel. Therefore you can utilize it to either greatly increase torque or greatly reduce speed. It’ll typically take multiple reductions of a conventional gearset to achieve the same reduction degree of a one worm gear – meaning users of worm gears have got fewer shifting parts and fewer areas for failure.
A second reason to use a worm gear may be the inability to reverse the direction of power. Because of the friction between the worm and the wheel, it is virtually difficult for a wheel with push used to it to begin the worm moving.
On a standard gear, the input and output can be switched independently once enough force is applied. This necessitates adding a backstop to a typical gearbox, further increasing the complication of the apparatus set.
Why Not to Use Worm Gears
There is one particularly glaring reason why you might not select a worm gear more than a standard gear: lubrication. The movement between the worm and the wheel gear faces is entirely sliding. There is absolutely no rolling element of the tooth get in touch with or interaction. This makes them fairly difficult to lubricate.
The lubricants required are often very high viscosity (ISO 320 and greater) and thus are tough to filter, and the lubricants required are typically specialized in what they do, requiring something to be on-site specifically for that type of equipment.
Worm Gear Lubrication
The primary problem with a worm gear is how it transfers power. It is a boon and a curse at the same time. The spiral motion allows huge amounts of reduction in a comparatively small amount of space for what is required if a typical helical equipment were used.
This spiral motion also causes an incredibly problematic condition to be the principal mode of power transfer. That is commonly known as sliding friction or sliding use.
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With a typical gear set the energy is transferred at the peak load stage on the tooth (known as the apex or pitchline), at least in a rolling wear condition. Sliding occurs on either side of the apex, but the velocity is relatively low.
With a worm gear, sliding motion is the only transfer of power. As the worm slides over the tooth of the wheel, it slowly rubs off the lubricant film, until there is absolutely no lubricant film still left, and for that reason, the worm rubs at the steel of the wheel in a boundary lubrication regime. When the worm surface area leaves the wheel surface, it accumulates more lubricant, and begins the process once more on the next revolution.
The rolling friction on an average gear tooth requires small in the form of lubricant film to fill in the spaces and separate both components. Because sliding takes place on either aspect of the apparatus tooth apex, a slightly higher viscosity of lubricant than is definitely strictly needed for rolling wear is required to overcome that load. The sliding happens at a relatively low velocity.
The worm on a worm set gear turns, and while turning, it crushes against the load that’s imposed on the wheel. The only way to prevent the worm from touching the wheel is usually to possess a film thickness large enough to not have the whole tooth surface wiped off before that portion of the worm has gone out of the load zone.
This scenario requires a special sort of lubricant. Not only will it will have to be a comparatively high viscosity lubricant (and the bigger the load or temperature, the higher the viscosity must be), it will need to have some way to help get over the sliding condition present.
Read The Right Method to Lubricate Worm Gears to find out more on this topic.
Viscosity is the major element in preventing the worm from touching the wheel in a worm gear set. As the load and size of gearing determines the required lubricant, an ISO 460 or ISO 680 is fairly common, and an ISO 1000 is not unheard of. If you have ever really tried to filter this range of viscosity, you know it is problematic since it is most likely that non-e of the filters or pumps you have got on-site will be the appropriate size or ranking to function properly.
Therefore, you’ll likely have to get a specific pump and filter for this type of unit. A lubricant that viscous takes a gradual operating pump to prevent the lubricant from activating the filter bypass. It will require a huge surface area filter to allow the lubricant to stream through.
Lubricant Types to consider
One lubricant type commonly used in mixture with worm gears is mineral-based, compounded equipment oils. There are no additives which can be placed into a lubricant that can make it conquer sliding wear indefinitely, however the natural or synthetic fatty additive combination in compounded gear oils results in great lubricity, providing a supplementary way of measuring protection from metal-to-metal get in touch with.
Another lubricant type commonly used with worm gears is mineral-based, industrial extreme pressure (EP) gear oils. There are several problems with this kind of lubricant in case you are using a worm gear with a yellow metallic (brass) component. However, when you have fairly low operating temperature ranges or no yellow metallic present on the apparatus tooth surfaces, this lubricant works well.
Polyalphaolefin (PAO) equipment lubricants work very well in worm gear applications because they naturally have got good lubricity properties. With a PAO equipment oil, it is necessary to view the additive package, because these can possess EP additives. A standard-duty antiwear (AW) fortified gear essential oil will typically become acceptable, but be sure the properties are appropriate for most metals.
The author recommends to closely view the wear metals in oil analysis testing to make sure that the AW package isn’t so reactive concerning trigger significant leaching from the brass. The effect should be far less than what would be noticed with EP actually in a worst-case scenario for AW reactivity, but it can arrive in metals examining. If you need a lubricant that can handle higher- or lower-than-typical temperature ranges, the right PAO-based product is probable available.
Polyalkylene glycols (PAG), a fourth kind of lubricant, are getting more prevalent. These lubricants have exceptional lubricity properties, , nor contain the waxes that trigger low-temperature issues with many mineral lubricants, producing them a great low-temperature choice. Caution should be taken when working with PAG oils because they are not appropriate for mineral oils, and some seals and paints.
Metallurgy of Worm Gears
The most common worm gears are created with a brass wheel and a steel worm. That is because the brass wheel is normally easier to replace compared to the worm itself. The wheel is manufactured out of brass because it was created to be sacrificial.
When the two surfaces enter into contact, the worm is marginally secure from wear because the wheel is softer, and therefore, the majority of the wear occurs on the wheel. Oil analysis reports on this type of unit almost always show some degree of copper and low degrees of iron – as a result of the sacrificial wheel.
This brass wheel throws another problem in to the lubrication equation for worm gears. If a sulfur-phosphorous EP gear essential oil is placed into the sump of a worm gear with a brass wheel, and the temperature is certainly high enough, the EP additive will activate. In normal steel gears, this activation produces a thin coating of oxidation on the surface that really helps to protect the apparatus tooth from shock loads and various other extreme mechanical conditions.
On the brass surface however, the activation of the EP additive results in significant corrosion from the sulfur. In a brief amount of time, you can reduce a significant portion of the strain surface of the wheel and cause major damage.
Other Materials
A few of the less common materials within worm gear models include:
Steel worm and steel worm wheel – This application does not have the EP complications of brass gearing, but there is no room for mistake included in a gearbox such as this. Repairs on worm gear sets with this mixture of metal are usually more costly and more time consuming than with a brass/steel worm gear set. This is since the material transfer associated with failure makes both the worm and the wheel unusable in the rebuild.
Brass worm and brass worm wheel – This program is most likely found in moderate to light load situations because the brass can only just hold up to a lower amount of load. Lubricant selection on this metal combination is flexible because of the lighter load, but one must still consider the additive restrictions regarding EP due to the yellow metal.
Plastic on metal, upon plastic, and other similar combinations – That is typically within relatively light load applications, such as robotics and auto components. The lubricant selection depends on the plastic used, because many plastic types react to the hydrocarbons in regular lubricant, and thus will require silicon-based or other nonreactive lubricants.
Although a worm gear will always have a few complications compared to a typical gear set, it can easily be a highly effective and reliable device. With a little focus on set up and lubricant selection, worm gears can offer reliable service as well as any other kind of gear set.
A worm drive is one particular worm gear set system in which a worm meshes with a worm equipment. Even it is basic, there are two essential elements: worm and worm equipment. (Also, they are known as the worm and worm wheel) The worm and worm wheel is essential motion control component providing large rate reductions. It can reduce the rotational rate or boost the torque output. The worm drive motion advantage is that they can transfer movement in right angle. It also has an interesting house: the worm or worm shaft can simply turn the gear, but the gear can not convert the worm. This worm drive self-locking feature let the worm gear includes a brake function in conveyor systems or lifting systems.
An Intro to Worm Gearbox
The most important applications of worm gears is used in worm gear box. A worm gearbox is named a worm reduction gearbox, worm gear reducer or a worm drive gearbox. It includes worm gears, shafts, bearings, and box frames.
The worm equipment, shafts, bearings load are supported by the box shell. So, the gearbox housing must have sufficient hardness. Or else, it will result in lower transmitting quality. As the worm gearbox includes a durable, tranny ratio, small size, self-locking ability, and simple structure, it is often used across a wide selection of industries: Rotary table or turntable, material dosing systems, auto feed machinery, stacking machine, belt conveyors, farm choosing lorries and more automation market.
How to Select High Efficient Worm Gearbox?
The worm gear manufacturing process is also not at all hard. However, there exists a low transmission performance problem if you don’t know the how to choose the worm gearbox. 3 basic indicate choose high worm equipment efficiency that you ought to know:
1) Helix angle. The worm gear drive efficiency mostly rely on the helix position of the worm. Usually, multiple thread worms and gears is certainly more efficient than one thread worms. Proper thread worms can increase efficiency.
2) Lubrication. To select a brand lubricating essential oil can be an essential factor to boost worm gearbox performance. As the correct lubrication can reduce worm gear action friction and temperature.
3) Material selection and Gear Manufacturing Technology. For worm shaft, the material should be hardened metal. The worm gear materials ought to be aluminium bronze. By reducing the worm equipment hardness, the friction on the worm teeth is reduced. In worm manufacturing, to use the specific machine for gear slicing and tooth grinding of worms can also increase worm gearbox efficiency.
From a huge transmission gearbox capacity to a straight small worm gearbox load, you can choose one from an array of worm reducer that precisely suits your application requirements.
Worm Gear Container Assembly:
1) You can complete the installation in six various ways.
2) The installation should be solid and reliable.
3) Make sure to verify the connection between the electric motor and the worm gear reducer.
4) You must make use of flexible cables and wiring for a manual installation.
By using the innovative science and drive technology, we’ve developed several unique “square container” designed from high-quality aluminium die casting with a lovely appearance. The modular worm gearbox design series: worm drive gearbox, parallel shaft gearbox, bevel helical gearbox, spiral bevel gearbox, coaxial gearbox, correct angle gearbox. An NMRV series gearbox is a standard worm gearbox with a bronze worm gear and a worm. Our Helical gearbox product line consists of four universal series (R/S/K/F) and a step-less quickness variation UDL series. Their structure and function are similar to an NMRV worm gearbox.
Worm gears are constructed of a worm and a equipment (sometimes known as a worm wheel), with non-parallel, non-intersecting shafts oriented 90 degrees to one another. The worm is certainly analogous to a screw with a V-type thread, and the gear is definitely analogous to a spur gear. The worm is normally the generating component, with the worm’s thread advancing one’s teeth of the gear.
Such as a ball screw, the worm in a worm gear might have an individual start or multiple starts – and therefore there are multiple threads, or helicies, on the worm. For a single-start worm, each complete turn (360 degrees) of the worm increases the equipment by one tooth. Therefore a gear with 24 teeth provides a gear reduced amount of 24:1. For a multi-begin worm, the gear reduction equals the amount of teeth on the gear, divided by the number of begins on the worm. (That is different from almost every other types of gears, where in fact the gear reduction is certainly a function of the diameters of the two components.)
The worm in a worm gear assembly can have one start (thread) or multiple starts.
Picture credit: Kohara Gear Sector Company, Ltd.
The meshing of the worm and the apparatus is an assortment of sliding and rolling actions, but sliding contact dominates at high reduction ratios. This sliding action causes friction and warmth, which limits the effectiveness of worm gears to 30 to 50 percent. In order to minimize friction (and therefore, heat), the worm and equipment are constructed with dissimilar metals – for example, the worm could be produced of hardened metal and the gear manufactured from bronze or aluminum.
Although the sliding contact reduces efficiency, it provides very quiet operation. (The use of dissimilar metals for the worm and gear also contributes to quiet procedure.) This makes worm gears ideal for use where sound should be minimized, such as in elevators. In addition, the utilization of a softer material for the gear implies that it can absorb shock loads, like those skilled in heavy equipment or crushing machines.
The primary advantage of worm gears is their capability to provide high reduction ratios and correspondingly high torque multiplication. They may also be used as speed reducers in low- to medium-speed applications. And, because their reduction ratio is founded on the amount of gear teeth by itself, they are more compact than other styles of gears. Like fine-pitch business lead screws, worm gears are typically self-locking, which makes them ideal for hoisting and lifting applications.
A worm equipment reducer is one type of reduction gear box which includes a worm pinion input, an output worm gear, and includes a right angle output orientation. This type of reduction gear box is generally used to take a rated motor speed and produce a low speed result with higher torque worth based on the reduction ratio. They often times can resolve space-saving problems because the worm equipment reducer is one of the sleekest decrease gearboxes available because of the small diameter of its output gear.
worm gear reducerWorm gear reducers are also a popular type of rate reducer because they offer the greatest speed decrease in the smallest package. With a higher ratio of speed decrease and high torque result multiplier, it’s unsurprising that lots of power transmission systems utilize a worm gear reducer. Some of the most typical applications for worm gears are available in tuning instruments, medical examining equipment, elevators, security gates, and conveyor belts.
Torque Transmission provides two sizes of worm equipment reducer, the SW-1 and the SW-5 and both can be found in a range of ratios. The SW-1 ratios include 3.5:1 to 60:1 and the SW-5 ratios include 5:1 to 100:1. Both these options are produced with tough compression-molded glass-fill polyester housings for a durable, long lasting, light weight speed reducer that is also compact, non-corrosive, and nonmetallic.
Features
Our worm gear reducers offer an option of a solid or hollow output shaft and show an adjustable mounting position. Both the SW-1 and the SW-5, however, can withstand shock loading better than other reduction gearbox styles, making them ideal for demanding applications.
Rugged compression-molded glass-fill up polyester housing
Light-weight and compact
Non corrosive
Non metallic
Range of ratios
SW-1, 3.5:1 to 60:1
SW-5, 5:1 to 100:1
Grease Lubrication
Solid or Hollow output shaft
Adjustable mounting position
Overview
Technical Info
Low friction coefficient on the gearing for high efficiency.
Powered by long-lasting worm gears.
Minimal speed fluctuation with low noise and low vibration.
Lightweight and compact relative to its high load capacity.
Compact design
Compact design is one of the key terms of the typical gearboxes of the BJ-Series. Further optimisation can be achieved by using adapted gearboxes or special gearboxes.
Low noise
Our worm gearboxes and actuators are really quiet. This is due to the very smooth working of the worm equipment combined with the utilization of cast iron and high precision on component manufacturing and assembly. In connection with our precision gearboxes, we take extra care of any sound which can be interpreted as a murmur from the gear. So the general noise level of our gearbox can be reduced to a complete minimum.
Angle gearboxes
On the worm gearbox the input shaft and output shaft are perpendicular to each other. This often proves to become a decisive advantage producing the incorporation of the gearbox significantly simpler and smaller sized.The worm gearbox is an angle gear. This is an edge for incorporation into constructions.
Solid bearings in solid housing
The output shaft of the BJ worm gearbox is quite firmly embedded in the gear house and is ideal for immediate suspension for wheels, movable arms and other areas rather than having to create a separate suspension.
Self locking
For larger equipment ratios, BJ-Gear’s worm gearboxes will provide a self-locking impact, which in many circumstances can be utilized as brake or as extra protection. Also spindle gearboxes with a trapezoidal spindle are self-locking, making them well suited for an array of solutions.