RU2725660C2 - Environmentally oriented energy-efficient gearbox for household appliances - Google Patents

Abstract

FIELD: planetary reduction gears.SUBSTANCE: planetary-type reduction gear, mainly for household appliances, consists of one or more stages, each of which includes a sun gear, satellite gears, a satellite gears carrier, a gear rim, mounted in a common cylindrical housing, on both sides closed by covers, said covers have holes, one—for the input shaft of the electric motor, the other—for power takeoff. Between the inner surface of the body and each toothed rim there is a resilient element allowing the toothed rim in the process of movement to move in radial direction.EFFECT: reduced noise during operation of reduction gear.7 cl, 14 dwg

Description

The claimed technical solution relates to household appliances, namely to mechanisms in the composition of devices with electric drive.

Known devices of electric drives for household appliances, containing a gearbox to reduce engine speed and increase the torque on the output shaft.

In the majority of such gearboxes are made with gear or worm gears, or with a belt drive, or a combination of them.

Known, for example, gearboxes for household appliances - CN20152108653U (02/13/2015) or CN201620014276U (01/05/2016).

The disadvantage of this type of gearboxes is the small contact area of the interacting gears (worm), and as a result, increased losses during operation. In addition, if the gears are made of metal, especially the gears of the first stages, the increased noise of the mechanism.

Known gearbox containing a belt drive - patent RU 2010066 (03/29/1991).

The disadvantage of this type of gearboxes is the low reliability (resource) of the belt drive.

A common drawback of these gearboxes is the open or semi-open execution of the mechanism, which leads to clogging of the grease, clogging of the mating working surfaces of the gears.

Known planetary gearbox for household appliances (electric drill, power unit of the food processor) CN201621417011U (12/22/2016), free from these shortcomings.

The document proposes to place the gear on noise and vibration-absorbing pillows.

The disadvantage of this gearbox is the lack of noise and vibration absorption during operation.

Known gearbox according to the application CN201610359787A (05/27/2016), in which the noise level in the planetary gearbox is reduced by placing the gearbox entirely in the soundproof casing.

The disadvantage of this device is the inconvenience of use in the field of household appliances.

This device is selected as a prototype.

The technical result of the proposed solution is to reduce noise during operation of the gearbox.

Another technical result is the reduction of vibrations, including as a result of stresses in the connection node of the gearbox with an external device - a nozzle or with another final actuator.

The aim of the proposed solution is to obtain an electric drive with low vibration and noise characteristics, which, along with the use of a low-noise electric motor, will make it possible to obtain low-noise and low-vibration household appliances.

An additional goal is to increase the adaptability (adaptability) of the output gear unit to the reception of the input shaft of the attachment nozzle.

An additional goal is to obtain an environmentally friendly (oriented) design, in the production of which regenerated materials would be used to the maximum, and during operation and disposal, damage to the environment would be minimized.

Known gearboxes do not allow to achieve the specified technical result.

Accepted Designations

1 - front housing cover.

2 - insert into the output device, protective.

3 - drove the 3rd step.

4 - satellites of the 3rd stage.

5 - gear ring of the 3rd stage.

6 - gear housing.

7 - drove the 2nd stage.

8 - satellites of the 2nd stage.

9 - gear ring of the 2nd stage.

10 - drove the 1st stage.

11 - satellites of the 1st stage.

12 - gear ring of the 1st stage.

13 - the back cover of the case.

14 - gear on the motor shaft.

15 - damping element.

DESCRIPTION OF GRAPHIC MATERIAL

In FIG. 1. shows a comparative table of the parameters of gearboxes of different designs.

In FIG. 2 shows the assembly diagram of the gearbox.

In FIG. 3 shows a gearbox in section.

In FIG. 4, 5 show the location of the damping elements inside the housing.

In FIG. 6a shows the implementation of the damping elements in the form of tides on the inner side of the plastic gear housing.

6b, the interaction of the damping elements of FIG. 6a with a ring gear.

In FIG. 7a, 7b show methods for reducing the hardness of the body material to increase damping properties in the area of interaction with the ring gear.

In FIG. 8a, 8b, 10 show possible variations of the shape of the tides and the location of the voids to obtain varying degrees of rigidity of the body material at the interface with the ring gear.

In FIG. 9 shows the implementation of the damping element in the form of a spring insert from another material or the same as the case.

In FIG. 11 shows an embodiment of a damping element in the form of an elastic insert of another material.

SHORT DESCRIPTION.

The claimed technical result is achieved through the use of a planetary gear, the satellite gears of at least the first stage of which are made of plastic to reduce noise during operation.

To reduce the noise level, all or part of the gears can be helical.

To reduce vibration caused by inaccuracies in the manufacture of parts, an elastic element is placed between the gear rims and the body, the deformation of which compensates for possible displacements of the gear rim in the radial direction.

The specified elastic element can be made in the body (in the composition) of the housing. This can be plastic tides, creating a softer area near the inner surface of the housing, directly adjacent to the ring gear.

To increase the adaptability (adaptability) of the output unit of the gearbox to the reception of the input shaft of the attachment nozzle, the receiving device (in particular, with an internal hexagonal hole) is connected to the carrier of the last gear stage with the possibility of some deviation from the axis in any radial direction, as well as with the possibility of deviation along the corner.

DETAILED DESCRIPTION

The claimed technical result is achieved thanks to several measures below. In the claimed planetary gearbox, satellite gears of at least the first stage of which are made of plastic to reduce noise during operation.

Perhaps made of plastic gears of the second stage. The gears of the subsequent stages have a low rotation speed, and are also more loaded, so it is more justified to make them out of metal.

To improve the supply of lubricant to the contact point, the metal gears can be made by powder sintering, which allows to obtain a loose, permeable to the lubricant structure without sacrificing strength.

To reduce the noise level, the gears of all or part of the steps can be helical.

To reduce vibration caused by inaccuracies in the manufacture of parts, an elastic element is placed between the gear rims and the body, the deformation of which compensates for possible displacements of the gear rim in the radial direction.

The specified elastic element can be made in the body (in the composition) of the housing.

It can be plastic tides, for example, triangular, rectangular or other shape.

It is possible to create a local, more elastic (soft) area near the inner surface of the housing, directly adjacent to the ring gear. The elastic (Soft) region can be realized by creating voids in the form of channels of different shapes and sizes of the cross section, bubbles (foaming), applying a plastic coating softer than the material of the body, etc.

To reduce the vibration caused by the misalignment of the output gear unit and the input shaft (shank) of the replaceable nozzle, as well as to increase the adaptability (adaptability) of the output gear unit to the reception of the input shaft (shank) of the attachment nozzle, the receiving device (in this particular case, with an internal hex hole ) is connected to the carrier of the last gear stage with the possibility of some deviation from the axis in any radial direction, as well as with the possibility of deviation in angle.

This will allow you to not apply additional forces to the input shaft of the replaceable nozzle (for example, a meat grinder) when connecting the nozzle with the gearbox. It will also reduce vibration and noise at the junction of the gearbox with the nozzle, and avoid premature failure of the gearbox parts in case of mismatch between the axes of the gearbox output device and the nozzle input shaft.

The fundamental embodiment of the design of the inventive device (planetary gear) is selected based on considerations of obtaining higher efficiency in production, disposal, and most importantly in operation.

Gearboxes of different circuit diagrams were analyzed, several variants of each. Data on key parameters taken into account are summarized in a table (Fig. 1).

In FIG. 1 the following notation is applied.

G - weight, importance, significance, indicator

E - degree of compliance with the requirements of the technical specifications for a particular product.

GxE - a general indicator for one position.

Then GxE indicators are summarized and get the final indicator for each technical solution.

From the presented table it can be seen that only the planetary gear does not give the maximum winning indicator in comparison with the belt-gear transmission for the selected evaluation indicators. However, if we additionally take into account environmental, hygienic, overall, and a number of other indicators, the total loss in bearings, the load on the contacting surfaces, the planetary gearbox is significantly superior to other types.

The gearbox is collected as follows (Fig. 2, 3).

If the damping element (s) are made as a separate part (s), then a damping element or a set of damping elements is inserted into the housing 6.

A protective cap 2 is pressed into the carrier of the 3rd stage 3. The satellite gears 4 and the ring gear 5 are installed.

The resulting assembly is inserted into the housing 6 and closed with a front cover 1.

Collect the 2nd stage. In the carrier of the 2nd stage 7, the satellite gears 8 and the ring gear 9 are installed. The resulting assembly is inserted into the housing 6, connecting with the 3rd stage.

Collect the 1st step. In the carrier of the first stage 10, satellite gears 11 and the ring gear 12 are installed. The resulting assembly is inserted into the housing 6, connecting with the second stage.

Lubricant is placed inside.

Close the back cover. Are fixed. Each of the covers with the housing is tightened with screws.

Noise reduction works as follows.

The pinion gear 14 on the shaft of the electric motor transmits rotation to the satellite gears 11 made of plastic.

The first gear stage operates at high speeds, so it creates the greatest noise and vibration. Plastic gears dampen noise to a large extent.

When the gears — the sun, satellite, and ring gear — are operating, vibrations may occur due to inaccurate manufacturing of mating parts — gears, shafts, bearings. Vibrations, interacting with each other, are added and subtracted. The total vibration is transmitted to the housing through a damping element or several damping elements. Damping elements dampen vibration and noise.

In the described embodiment of the gearbox, the location of the damping elements inside the housing is shown in FIG. 4, 5. In this case, the damping elements in the form of protrusions are molded on the inside of the plastic case.

To obtain the necessary level of damping necessary for the implementation of the gearbox of the claimed design - with partially metal and partially plastic elements, the claimed purpose - household, the required noise level, weight and dimensions, other factors, a study was conducted to evaluate the properties, labor costs, manufacturability, cost and a number of other factors for various versions of the damping elements on which the gear crowns of the steps are based.

As a result, it turned out that the embodiment corresponding to FIG. 6 is simpler than others in execution, however, it has less stable damping characteristics, and is difficult to assemble. For each variant of the specific damping characteristics (force x movement), it is necessary to choose the geometric parameters and the repetition rate of the protrusions, based on the characteristics of the housing material.

Methods for local reduction of the hardness of the body material were also considered to increase the damping properties in the area of interaction with the ring gear (Fig. 7).

These methods showed more stable characteristics of the dependence of stiffness on the number and size of voids in the material. However, the implementation of this design in production is significantly more complicated.

We studied various options for the shape of the tides and their frequency around the circumference, the location of voids of different sizes in the tides to obtain different degrees of rigidity of the material of the body at the interface with the gear ring (Fig. 8, 10). As a result, it turned out that by changing the shape and size, as well as the frequency of the protrusions on the inner side of the housing, the necessary degree of stiffness / damping can be obtained more predictably. Designs showed acceptable performance for ease of assembly. A difficult factor was the fulfillment of voids in the protrusions (tides).

In FIG. 9 shows the implementation of the damping element in the form of a spring insert from another material or the same as the case. This solution is most simple in production. The selection of stiffness is performed by selecting the number of insert waves, thickness, taking into account the hardness and spring properties of the material of the insert. Ease of assembly is satisfactory.

In FIG. 11 shows an embodiment of a damping element in the form of an elastic insert of another material. In this embodiment, the damping properties are entirely dependent on the material used. Ease of assembly is satisfactory.

The output device of the gearbox is made with the ability to work normally in the presence of some deviation from the alignment of the connected shafts, as well as with some angular deviation.

This can be implemented in any known manner, for example in the form of a coupling or a hinge, or a combination thereof.

In the particular case, and this is proposed as the preferred embodiment, this function is realized by performing a guaranteed radial clearance in the range of 0.1 to 0.5 mm in the coupling of the output of the reducer 2 and the nozzle inlet. This value exceeds the manufacturing accuracy of the mating devices, therefore, it compensates for misalignment. At the same time, such a gap will allow sufficient freedom of angular movement.

The gearbox is industrially applicable, since all parts are as unified as possible, and can be manufactured on industrial equipment in large-scale and mass production.

Claims (10)

1. A planetary gear type, mainly for household appliances, consisting of one or more steps, each of which includes a sun gear, satellite gears, a satellite gear carrier, a gear ring mounted in a common cylindrical body, closed on both sides by covers, these covers have holes, one for the input shaft of the electric motor, the other for power take-off, characterized in that between the inner surface of the housing and each gear ring there is an elastic element that allows the ring gear to move in the radial direction during operation. 2. The planetary gear type according to claim 1, characterized in that the elastic element is made in the form of a spring insert between the housing and the ring gear. 3. The planetary gear type, mainly for household appliances, consisting of one or more steps, each of which includes a sun gear, satellite gears, a satellite gear carrier, a gear ring mounted in a common cylindrical body, covered on both sides by covers, these covers have holes, one for the input shaft of the electric motor, the other for power take-off, characterized in that each ring gear on the periphery is supported by an elastic element that allows the ring gear to move in the radial direction during operation. 4. The planetary gear type according to claim 3, characterized in that the elastic element is molded on the inside of the housing from the same or another material in the form of a set of elastic elements. 5. A gearbox for household appliances according to claim 1 or 3, characterized in that the satellite gears of at least the first stage are made of plastic. 6. The planetary gear type according to any one of paragraphs. 1 to 5, characterized in that it further comprises an adapter for connecting the carrier of the last stage with the shaft of the attached device (attached nozzle). 7. A planetary gear type, mainly for household appliances, consisting of one or more steps, each of which includes a sun gear, satellite gears, a satellite gear carrier, a gear ring mounted in a common cylindrical body, covered with lids on both sides, these covers have holes, one for the input shaft of the engine, the other for power take-off, the last stage equipped with an adapter for connecting external devices, characterized in that the adapter is mounted on the carrier of the last stage with the possibility of radial movement and deviation in angle.

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