Wave reducer: definition, description, types and principle of operation

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Wave gearbox, or, as it is also called, wave transmission, is based on transmitting rotational motion, which occurs due to the running wave deformation of one of the gears.

Wave transmissions

The emergence and further development of wave transmission was carried out back in 1959. The inventor, as well as the person who patented this technology, was the American engineer Masser.

The wave reducer consists of several main elements:

• Stationary wheel with internal teeth.
• A spinning wheel with external teeth.
• Carrier.

Among the advantages that can be distinguished from this method of transmitting motion are less weight and dimensions of the device, higher accuracy from a kinematic point of view, as well as less backlash. If necessary, this type of motion transmission can also be used in a sealed space without using sealing glands. This indicator is most important for such equipment as aviation, space, underwater. Besides,the wave reducer is also used in some machines used in the chemical industry.

The principle of operation of the gearbox

From a kinematic point of view, wave gears are a kind of planetary gears that have one flexible and gear wheel.

The principle of operation of the wave reducer is as follows. The fixed wheel of the device is mounted in the desired housing, and it is made in the form of a simple gear wheel with internal gearing. A flexible gear wheel is made in the form of a glass with a thin wall that is easily deformable. In the thicker part of the same wheel, that is, the left, teeth are cut, while the right part is made in the form of a shaft. The simplest element is the carrier, which consists of an oval cam and a bearing.

The movement itself is carried out due to the fact that the ring gear of the flexible wheel is deformed.

Reducer Designs

At present, science knows a wide variety of designs for a wave gearbox. Most often, the purpose of all these devices is to convert the input rotational motion into an output rotational or output translational. It is also worth noting that wave transmission can be considered as a kind of multi-threaded planetary mechanism. This is quite possible, since these mechanisms have a multi-zone, and if we take into account the gear mechanism, then also a multi-pair contact between the output link and the flexible wheel of the mechanism. CanIt should be noted that at the nominal load on the wave reducer, only 15 to 20% of all teeth of the device are engaged. It is for this reason that fine-module mechanisms are used in all wave transmissions, the number of teeth on which is in the range from 100 to 600. It can also be added that, depending on the number of zones or waves in the device, they are divided into single-wave, double-wave, etc.

Wave gear motor

Description of this type of wave transmission can be made on the basis of the motor reducer model MVz2-160-5, 5. This model has a double wave gear. The design of this gearbox consists of a flexible wheel, which is made in the form of a ring with thin walls and two gear rims. In addition, the design also includes a cam wave generator common to these parts, which has a flexible bearing.

Also, this model has several features regarding the design of the gearbox:

1. The size along the axis of the shaft is small.
2. The wave generator is of floating type, and the connection with the motor shaft is articulated.
3. Straight-sided splines are located at the end of the output shaft of this device.

This type of geared motor can be used as an individual drive module.

Technical parameters of geared motor

The technical parameters for the wave gear motor are a few basic criteria:

• The first parameter to matchthe gearbox is the torque on the output shaft. It should be - 250 N⋅m.
• The second parameter is the speed of the gearbox shaft. The indicator of this parameter should be - 5.5 min-1.
• The third parameter for this device is the gear ratio. The indicator of this parameter is 264.
• The efficiency of the wave gear motor must be 0.7.
• The parameters of the electric motor for this model are as follows: 0, 31 kW power, RPM 1450 min-1, the operating voltage for this mechanism is 220V or 380V.
• The total weight of the device is 20 kg.

These are the main parameters that apply to the wave gear motor.

Gear train

Not so long ago, engineers created a new type of gear train, which, in terms of its parameters and design, is similar to a planetary gear, but at the same time it has a fundamentally new transmission of rotation. These new inventions are wave gear reducers. In order to transmit rotational motion in these devices, a wave running deformation was achieved, which lends itself to one of the gear wheels of the gearbox. This invention has proved to be excellent in some kind of servo systems, as well as in automatic control systems with a high requirement for accuracy. These gearboxes received such a specific purpose due to their characteristics: low physical weight, as well as the small size of the entire device as a whole, which at the same time has a large gear ratio,characterized by a higher efficiency, that is, efficiency, small backlash, as well as low wear of gearbox parts. It was these parameters that became decisive in determining the purpose of work for wave gear reducers.

Winch with wave gear

Wave gearboxes can be of two types - gear and worm. The use of a winch in this device found itself only when using a worm-type gearbox. Also, in worm-type wave gearboxes using a winch, there are two ways to position the worm. The bottom setting when it is under the worm wheel, and the top setting when the worm is above the same wheel.

Also, the winch drive can be used for installation on a spacecraft. The winch drive for the spacecraft is a two-stage wave reducer. The purpose of this device on such ships is to transfer rotation to a completely sealed space. Since the gearbox is a two-stage, the first stage is planetary, and the second is a wave gear. It is also worth noting that it is possible to make the device self-braking. To do this, it is necessary to replace the planetary gear in the gearbox with a worm gear.

Reducer calculations

As with any other part, to create a gearbox, it is necessary to carry out certain calculations that will show whether the device is capable of performing its functions, and also from what materi althe device must be running, etc. The main criterion for calculating the wave reducer, its performance, is the strength of the flexible wheel. This parameter can be estimated using the fatigue resistance of the ring gear. The main overall dimension of the transmission is the inner diameter of the flexible wheel. It is determined by the approximate dependence of fatigue resistance, taking into account normal stresses.