Helical Gear Reducer

Worm gears are usually used when large rate reductions are needed. The reduction ratio depends upon the number of begins of the worm and amount of the teeth on the worm gear. But worm gears have sliding contact which is quiet but will produce heat and also have relatively low transmission efficiency.
For the materials for creation, in general, worm is made of hard metal as the worm gear is produced out of relatively soft steel such as aluminum bronze. This is since the number of teeth on the worm gear is relatively high in comparison to worm with its number of begins being usually 1 to 4, by reducing the worm equipment hardness, the friction on the worm teeth is reduced. Another feature of worm manufacturing may be the need of specific machine for gear cutting and tooth grinding of worms. The worm equipment, on the other hand, may be made out of the hobbing machine used for spur gears. But because of the different tooth shape, it is not possible to cut many gears simultaneously by stacking the gear blanks as can be done with spur gears.
The applications for worm gears include gear boxes, angling pole reels, guitar string tuning pegs, and in which a delicate velocity adjustment by utilizing a big speed reduction is necessary. While you can rotate the worm gear by worm, it is generally not possible to rotate worm utilizing the worm gear. That is called the personal locking feature. The self locking feature cannot continually be assured and another method is preferred for accurate positive reverse prevention.
Also there is duplex worm gear type. When using these, you’ll be able to adapt backlash, as when the teeth use necessitates backlash adjustment, without needing a alter in the center distance. There aren’t too many manufacturers who can create this type of worm.
The worm equipment is more commonly called worm wheel in China.
A worm gear 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 edition of 1 of the six basic machines. Fundamentally, a worm gear is usually a screw butted against what looks like a typical spur gear with slightly angled and curved tooth.
It adjustments the rotational movement by 90 degrees, and the plane of motion also changes because of the placement of the worm on the worm wheel (or simply “the wheel”). They are usually comprised of a steel worm and a brass wheel.
Worm Gear
Figure 1. Worm gear. Most worms (however, not all) are at the bottom.
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 face pushes on the teeth of the wheel. The wheel is definitely pushed against the load.
Worm Gear Uses
There are some reasons why one would select a worm gear over a standard gear.
The first one may be the high reduction ratio. A worm gear can have a massive reduction ratio with small effort – all one should do can be add circumference to the wheel. Thus you can use it to either greatly increase torque or greatly reduce speed. It will typically consider multiple reductions of a typical gearset to attain the same reduction degree of a single worm gear – which means users of worm gears have fewer moving parts and fewer places for failure.
A second reason to use a worm gear may be the inability to reverse the direction of power. Due to the friction between the worm and the wheel, it is virtually impossible for a wheel with push applied to it to start the worm moving.
On a standard gear, the input and output could be turned independently once enough force is applied. This necessitates adding a backstop to a standard gearbox, further raising the complication of the gear set.
YOU WILL WANT TO to Use Worm Gears
There is one especially glaring reason why one would not select a worm gear over a typical gear: lubrication. The movement between your worm and the wheel gear faces is entirely sliding. There is no rolling component to the tooth contact or conversation. This makes them relatively difficult to lubricate.
The lubricants required are often high viscosity (ISO 320 and better) and thus are difficult to filter, and the lubricants required are typically specialized in what they perform, requiring something to be on-site particularly for that type of equipment.
Worm Gear Lubrication
The main problem with a worm gear is how it transfers power. It really is a boon and a curse simultaneously. The spiral motion allows large sums of reduction in a comparatively little bit of space for what’s required if a standard helical equipment were used.
This spiral motion also causes a remarkably problematic condition to be the principal mode of power transfer. That is commonly known as sliding friction or sliding wear.
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With a typical gear set the energy is transferred at the peak load point on the tooth (known as the apex or pitchline), at least in a rolling wear condition. Sliding happens on either part of the apex, however the velocity is relatively low.
With a worm gear, sliding motion may be the only transfer of power. As the worm slides across the tooth of the wheel, it slowly rubs off the lubricant film, until there is absolutely no lubricant film remaining, and as a result, the worm rubs at the steel of the wheel in a boundary lubrication regime. When the worm surface leaves the wheel surface, it accumulates more lubricant, and begins the process over again on another revolution.
The rolling friction on a typical gear tooth requires little in the form of lubricant film to fill in the spaces and separate the two components. Because sliding happens on either side of the apparatus tooth apex, a slightly higher viscosity of lubricant than is usually strictly necessary 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, even though turning, it crushes against the strain that is imposed on the wheel. The only method to prevent the worm from touching the wheel is certainly to have a film thickness large enough to not have the whole tooth surface wiped off before that portion of the worm is out of the load zone.
This scenario requires a special sort of lubricant. Not just will it should be a comparatively high viscosity lubricant (and the higher the load or temperature, the higher the viscosity should be), it will need to have some way to greatly 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. While the load and size of gearing determines the mandatory lubricant, an ISO 460 or ISO 680 is rather common, and an ISO 1000 isn’t unheard of. If you have ever tried to filter this range of viscosity, you know it is problematic because it is most likely that non-e of the filters or pumps you have on-site would be the correct size or rating to function properly.
Therefore, you’ll likely have to get a particular pump and filter for this type of unit. A lubricant that viscous requires a gradual operating pump to prevent the lubricant from activating the filter bypass. It will also require a huge surface area filter to allow the lubricant to stream through.
Lubricant Types to Look For
One lubricant type commonly used in mixture with worm gears is mineral-based, compounded gear oils. There are no additives which can be placed into a lubricant that may make it overcome sliding wear indefinitely, however the natural or synthetic fatty additive mixture in compounded gear oils results in good lubricity, providing an extra measure of 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 some problems with this kind of lubricant in case you are using a worm gear with a yellow metal (brass) component. However, should you have relatively low operating temps or no yellow metallic present on the gear tooth areas, this lubricant is effective.
Polyalphaolefin (PAO) equipment lubricants work very well in worm equipment applications because they naturally have got great lubricity properties. With a PAO equipment oil, it is necessary to view the additive bundle, because these can have EP additives. A standard-duty antiwear (AW) fortified gear essential oil will typically end up being acceptable, but be sure the properties are compatible with most metals.
The writer recommends to closely watch the put on metals in oil analysis testing to ensure that the AW package isn’t so reactive as to trigger significant leaching from the brass. The effect should be far less than what will be noticed with EP also in a worst-case situation for AW reactivity, but it can show up in metals assessment. If you need a lubricant that may handle higher- or lower-than-typical temps, the right PAO-based product is likely available.
Polyalkylene glycols (PAG), a fourth kind of lubricant, are getting more prevalent. These lubricants have excellent lubricity properties, and do not support the waxes that cause low-temperature problems with many mineral lubricants, producing them an excellent low-temperature choice. Caution should be taken when using PAG oils because they are not compatible with mineral oils, and some seals and paints.
Metallurgy of Worm Gears
The most typical worm gears are made with a brass wheel and a steel worm. That is because the brass wheel is normally easier to replace than the worm itself. The wheel is made out of brass since it was created to be sacrificial.
When the two surfaces come into contact, the worm is marginally safe from wear because the wheel is softer, and therefore, most of the wear occurs on the wheel. Oil evaluation reports on this kind of unit more often than not show some degree of copper and low levels of iron – because of this of the sacrificial wheel.
This brass wheel throws another problem into the lubrication equation for worm gears. If a sulfur-phosphorous EP gear oil is put into the sump of a worm gear with a brass wheel, and the temperature is definitely high enough, the EP additive will activate. In normal metal gears, this activation generates a thin layer of oxidation on the surface that really helps to protect the gear tooth from shock loads and other extreme mechanical conditions.
On the brass surface however, the activation of the EP additive outcomes in significant corrosion from the sulfur. In a short amount of time, you can lose a substantial portion of the load surface area of the wheel and trigger major damage.
Other Materials
Some of the less common materials within worm gear sets include:
Steel worm and metal worm wheel – This application doesn’t have the EP complications of brass gearing, but there is no room for error built into a gearbox like this. Repairs on worm equipment sets with this combination of metal are usually more costly and additional time eating than with a brass/steel worm gear set. This is because the material transfer associated with failure makes both worm and the wheel unusable in the rebuild.
Brass worm and brass worm wheel – This app is most likely within moderate to light load situations because the brass can only keep up to a lesser amount of load. Lubricant selection upon this metal combination is flexible due to the lighter load, but one must still consider the additive limitations regarding EP because of the yellow metal.
Plastic on metal, upon plastic, and other comparable combinations – That is typically within relatively light load applications, such as robotics and automotive components. The lubricant selection depends on the plastic used, because many plastic varieties react to the hydrocarbons in regular lubricant, and thus will demand silicon-based or other non-reactive lubricants.
Although a worm gear will always have a couple of complications compared to a standard gear set, it can easily be a highly effective and reliable piece of equipment. With a little attention to set up and lubricant selection, worm gears can provide reliable service and also any other kind of gear set.
A worm drive is one particular worm gear set mechanism when a worm meshes with a worm gear. Even it is simple, there are two essential elements: worm and worm gear. (Also, they are called the worm and worm wheel) The worm and worm wheel is essential motion control component providing large rate reductions. It can decrease the rotational rate or boost the torque output. The worm drive movement advantage is they can transfer motion in right angle. In addition, it has an interesting real estate: the worm or worm shaft can certainly turn the gear, but the gear can not switch the worm. This worm drive self-locking feature let the worm gear includes a brake function in conveyor systems or lifting systems.
An Introduction to Worm Gearbox
The most important applications of worm gears is utilized in worm gear box. A worm gearbox is named a worm decrease gearbox, worm equipment reducer or a worm drive gearbox. It contains worm gears, shafts, bearings, and box frames.
The worm gear, shafts, bearings load are supported by the box shell. So, the gearbox housing will need to have sufficient hardness. Or else, it’ll 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 an array of industries: Rotary desk or turntable, materials dosing systems, car feed machinery, stacking machine, belt conveyors, farm choosing lorries and more automation industry.
How to Select High Efficient Worm Gearbox?
The worm gear manufacturing process is also relatively simple. However, there exists a low transmission performance problem if you don’t understand the how to choose the worm gearbox. 3 basic point to choose high worm equipment efficiency that you need to know:
1) Helix position. The worm gear drive efficiency mostly depend on the helix position of the worm. Usually, multiple thread worms and gears is usually more efficient than one thread worms. Proper thread worms can increase efficiency.
2) Lubrication. To select a brand lubricating oil can be an essential factor to improve worm gearbox effectiveness. As the correct lubrication can decrease worm gear action friction and high temperature.
3) Material selection and Gear Production Technology. For worm shaft, the material should be hardened steel. The worm gear material should be aluminium bronze. By reducing the worm equipment hardness, the friction on the worm the teeth is reduced. In worm manufacturing, to use the specialized machine for gear reducing and tooth grinding of worms can also increase worm gearbox efficiency.
From a big transmission gearbox capacity to an even small worm gearbox load, you can choose one from a wide variety of worm reducer that precisely suits your application requirements.
Worm Gear Package Assembly:
1) You may complete the set up in six various ways.
2) The installation should be solid and reliable.
3) Ensure that you verify the connection between your electric motor and the worm gear reducer.
4) You must make use of flexible cables and wiring for a manual set up.
With the help of the innovative science and drive technology, we’ve developed several unique “square container” designed from high-quality aluminium die casting with a beautiful appearance. The modular worm gearbox style series: worm drive gearbox, parallel shaft gearbox, bevel helical gearbox, spiral bevel gearbox, coaxial gearbox, right angle gearbox. An NMRV series gearbox is usually a standard worm gearbox with a bronze worm equipment and a worm. Our Helical gearbox product line comprises of four universal series (R/S/K/F) and a step-less swiftness variation UDL series. Their structure and function are similar to an NMRV worm gearbox.
Worm gears are made of a worm and a equipment (sometimes known as a worm wheel), with nonparallel, non-intersecting shafts oriented 90 degrees to each other. The worm can be 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 the teeth of the gear.
Such as a ball screw, the worm in a worm gear might have an individual start or multiple starts – meaning that there are multiple threads, or helicies, on the worm. For a single-start worm, each full switch (360 degrees) of the worm advances the gear by one tooth. Therefore a gear with 24 teeth will provide a gear reduced amount of 24:1. For a multi-start worm, the gear reduction equals the number of teeth on the gear, divided by the amount of starts on the worm. (That is different from almost every other types of gears, where the gear reduction is usually a function of the diameters of both 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 gear is a mixture of sliding and rolling actions, but sliding contact dominates at high reduction ratios. This sliding action causes friction and heat, which limits the efficiency of worm gears to 30 to 50 percent. To be able to minimize friction (and for that reason, high temperature), the worm and equipment are made of dissimilar metals – for instance, the worm may be made of hardened steel and the gear manufactured from bronze or aluminum.
Although the sliding contact reduces efficiency, it provides extremely quiet operation. (The utilization of dissimilar metals for the worm and gear also contributes to quiet procedure.) This makes worm gears suitable for use where noise should be minimized, such as in elevators. Furthermore, the usage of a softer material for the gear means that it could absorb shock loads, like those experienced in large equipment or crushing devices.
The primary benefit of worm gears is their capability to provide high reduction ratios and correspondingly high torque multiplication. They can also be utilized as speed reducers in low- to moderate-velocity applications. And, because their reduction ratio is based on the number of gear teeth only, they are smaller sized than other types of gears. Like fine-pitch business lead screws, worm gears are usually self-locking, making them ideal for hoisting and lifting applications.
A worm gear reducer is one type of reduction gear container which contains a worm pinion insight, an output worm gear, and features a right angle result orientation. This kind of reduction gear box is normally used to take a rated motor quickness and create a low speed output with higher torque worth based on the decrease ratio. They often times can resolve space-saving problems because the worm gear reducer is one of the sleekest decrease gearboxes available due to the small diameter of its output gear.
worm gear reducerWorm equipment reducers are also a favorite type of rate reducer because they provide the greatest speed reduction in the smallest package. With a higher ratio of speed reduction and high torque output multiplier, it’s unsurprising that lots of power transmission systems make use of a worm gear reducer. Some of the most typical applications for worm gears are available in tuning instruments, medical screening equipment, elevators, protection gates, and conveyor belts.
Torque Transmission offers two sizes of worm gear 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 of these options are produced with rugged compression-molded glass-fill up up polyester housings for a durable, long lasting, light weight speed reducer that’s also compact, non-corrosive, and nonmetallic.
Features
Our worm equipment reducers offer an option of a good or hollow result shaft and feature an adjustable mounting placement. Both the SW-1 and the SW-5, nevertheless, can endure 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-enduring worm gears.
Minimal speed fluctuation with low noise and low vibration.
Lightweight and compact in accordance with its high load capacity.
Compact design
Compact design is among the key phrases of the standard gearboxes of the BJ-Series. Further optimisation can be achieved by using adapted gearboxes or unique gearboxes.
Low noise
Our worm gearboxes and actuators are really quiet. This is because of the very smooth working of the worm equipment combined with the use of cast iron and high precision on component manufacturing and assembly. Regarding the our precision gearboxes, we take extra care of any sound that can be interpreted as a murmur from the apparatus. Therefore the general noise degree of our gearbox can be reduced to an absolute minimum.
Angle gearboxes
On the worm gearbox the input shaft and output shaft are perpendicular to each other. This often proves to be a decisive advantage producing the incorporation of the gearbox significantly simpler and more compact.The worm gearbox can be an angle gear. This is an advantage for incorporation into constructions.
Solid bearings in solid housing
The output shaft of the BJ worm gearbox is quite firmly embedded in the apparatus house and is perfect for direct suspension for wheels, movable arms and other areas rather than having to build a separate suspension.
Self locking
For larger equipment ratios, BJ-Gear’s worm gearboxes will provide a self-locking impact, which in many situations can be utilized as brake or as extra security. Also spindle gearboxes with a trapezoidal spindle are self-locking, making them perfect for an array of solutions.

We provide Helical Gear Reducer; call us to discover out much more.