RU2466315C1 - Planetary gear without carrier - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: planetary gear without carrier includes drive friction central wheel (1) with internal working surface, driven (2) and support (3) central gear wheels with inner teeth. Two main toothed satellite gears (4) are in internal engagement with driven and central support wheels. Two additional satellite gears (5), which have no teeth, are in friction interconnection with drive central wheel and main satellite gears equipped with the corresponding raceways. Driven central wheel (2) is provided with two rims located at some distance from each other in axial direction. Support and drive central wheels are located between them. Toothed rims of driven wheel are fixed on discs (6) with possibility of adjusting the angular position.

EFFECT: invention allows simplifying the design, improving manufacturability and enlarging layout capabilities of the device.

3 cl, 2 dwg

Description

The invention relates to mechanical engineering, namely to mechanical gears. It can be used in gearboxes of drives with large gear ratios, but not constantly operating at high loads.

Gearless planetary gears are known, for example: [US 5078665, F16H 1/32, 1992 or EP 1244880, F16H 1/28, 2002] containing three central gears and satellites interacting with them. One of the central wheels is driving, the other is driven, and the third is supporting. The driven and supporting wheels are made with internal teeth and are offset relative to each other along the main axis of the gearbox. The driving central wheel and the satellites are made with external teeth and have a width that is equal to the sum of the widths of the supporting and driven central wheels. The disadvantage of this transmission is that the drive central wheel is loaded with a skew moment applied from the side of the power wheels. This reduces the load capacity and transmission efficiency.

Driveless planetary gears are known, for example [US 3633441, F16H 1/28, 1970 and RU 2169867, F16H 1/46, 1999], similar to those described above, but having elongated central pinion gear and satellites. In such designs, the adverse effect of skew is reduced, although it does not completely disappear.

Such non-driven planetary gears are known that remove the problem of the mentioned distortion moment radically, for example [RU 1313076, F16H 1/46, 1995]. In this transmission, the supporting central wheel is made with two internal gear rims spaced at the edges of the gearbox. However, this eliminates the possibility of removing the torque from the output wheel in the axial direction, i.e., for example, using a coupling. Such a driveless planetary gear can only work in combination with another gear: chain, belt or gear, for example [SU 1460474, F16H 1/48, 1987], which carries out the movement in the radial direction, or serves to rotate the driven central wheel by an angle, significantly less than 360 degrees [US 3640150, F16H 1/32, 1970].

A known design of a non-separating rolling bearing [US 3937536, F16C 23/08, 1976]. This bearing contains an outer ring with an inner rolling surface, a pair of rings with an inner rolling surface located on the sides of the outer ring, rigidly connected with the shaft. Inside the rings are four rollers. Two of them (odd) interact with the outer ring, and the other two (even) interact with rings stationary relative to the shaft, and with odd rollers. This design cannot directly be used as a mechanical transmission.

The closest in design to the proposed non-drive planetary gear [SU 1744336, F16H 1/48, 1990] - a prototype containing three central wheels with internal teeth, gears meshing with them, as well as floating rings with a smooth outer working surface, interacting with the satellites. The supporting Central wheel is made with two crowns spaced relative to each other in the axial direction. The driven central wheel is located between them and therefore is intended only for the removal of movement in the radial direction. The driving central wheel interacts with the satellite rim located near one of its ends. Satellites crowns, designed to interact with each of the central wheels, have different numbers of teeth. It should be noted that to ensure the operability of such a design, the satellite rim interacting with the driving central wheel should have a significantly different (in this case, smaller) initial diameter than the rims interacting with the driven and supporting central wheels. Otherwise, the rotation of the satellite will take place under very unfavorable conditions for the transfer of forces.

The disadvantage of this design is the inability to remove the torque from the output wheel in the axial direction, i.e., for example, using a coupling. Such a transmission can only work in combination with another transmission, providing removal of movement in the radial direction, or serve to effect incomplete rotation of the driven central wheel.

The basis of the invention is the task of expanding the arsenal of means for reducing rotation speed, namely the creation of a new compact and technologically advanced driveless planetary gear.

Achievable technical result - simplification of the design, improving manufacturability and expanding the layout capabilities of the device.

The proposed non-drive planetary gear, like the prototype, contains a driving central wheel with an inner working surface, a driven and supporting central wheels with internal teeth, as well as two main satellites, which are in internal engagement with the driven and supporting central wheels. The novelty lies in the fact that the transmission contains two additional satellites without teeth, which are in frictional interaction with the driving central wheel and the main satellites, with each additional satellite interacting with two adjacent main satellites, the driven central wheel is made with two crowns spaced relative to each other each other in the axial direction, and the supporting and driving central wheels are located between them.

The radial reaction arising in gearing of the satellites with the power wheels is sufficient to provide the necessary pressure in the friction contacts of the mechanism. The use of friction rollers instead of gears can reduce the complexity of manufacturing a number of parts and somewhat reduce friction losses. Additional (friction) satellites do not increase the radial dimensions of the transmission, as they are located between the main (gear) satellites.

In the proposed design, it becomes possible to locate the driven shaft in the center, “inside” the transmission and take the moment off it directly, for example, using a coupling. Moreover, a rational design is in which the gears of the driven wheel are made on disks connected to the driven shaft by means of a spline connection.

To ensure the symmetry of the parts and the forces applied to the links of the mechanism, the transmission is equipped with a floating ring, supported by additional satellites, which has the same dimensions as the driving central wheel, but is located on the other side of the supporting central wheel.

An example of the implementation of the proposed transmission is illustrated by drawings, in which Fig. 1 shows the design of a planetless gearless transmission, and Fig. 2 is an axial section thereof.

The transmission comprises a driving central wheel 1 with a “smooth” inner working surface, a driven 2 and a supporting 3 central wheels with internal teeth, as well as two main satellites 4, which are in internal engagement with the driven 2 and supporting 3 central wheels. Two additional satellites 5, have no teeth, are in frictional interaction with the driving central wheel 1 and the main satellites 4. Moreover, each additional satellite 5 interacts with two adjacent main satellites 4, the driven central wheel 2 is made with two crowns spaced relative to each other in axial direction, and the supporting 3 and driving 1 of the Central wheels are located between them. The gear crowns of the driven wheel 2 are fixed with the possibility of adjusting the angular position on the disks 6 by bolts 10. The disks 6 are connected to the driven shaft 7 by means of a splined connection 8. The transmission is equipped with a floating ring 9, which has the same dimensions as the drive central wheel 1. It serves to ensure the symmetry of parts and forces applied to the links of the mechanism,

The transfer works as follows. The driving central wheel 1 rotates additional satellites 5 due to the friction forces, which, also due to the frictional forces, transmit the rotation to the satellites 4. The satellites 4 run around the stationary supporting central gear wheel 3 and, due to the difference in the numbers of teeth of the wheels 2 and 3, rotate the driven central wheel 2. From the crowns of this wheel through the disks 6 and spline connections 8, the rotation is transmitted to the driven shaft 7.

The gear ratio of the mechanism is calculated by the following formula: i ³ ₁₂ = [1+ (Z ₃ / Z ₄ ) (d ₄ / d ₁ )] / (1-Z ₃ / Z ₂ ),

where: Z ₂ and Z ₃ - the number of teeth of the driven 2 and supporting 3 of the Central wheels;

d ₁ and d ₄ - the diameters of the friction working surfaces of the driving Central wheel 1 and satellite 4.

Figure 1 and 2 shows an example of a driveless transmission having parameters:

Z ₂ = 102, Z ₃ = 100, Z ₄ = 40, d ₁ = 105 mm, d ₄ = 38 mm

additional gears Z ₅ = 16. Its gear ratio:

i ³ ₁₂ = [1+ (100/40) (38/105)] / (1-100 / 102) = 97.2

The proposed non-drive planetary gear is simple in design and manufacture, has a large gear ratio in one stage, is well assembled in coaxial gearboxes. It can find application in drives that do not work continuously under heavy loads, for example, instead of wave or worm gears.

Claims (3)

1. A gearless planetary gear comprising a driving central wheel with an inner working surface, a driven and supporting central wheels with internal teeth, two main satellites, which are in internal engagement with a driven and supporting central wheels, characterized in that it contains two additional satellites, not having teeth in frictional interaction with the driving Central wheel and the main satellites, and each additional satellite interacts with two adjacent main by satellites, the driven central wheel is made with two axles spaced apart from each other in the axial direction, and the supporting and driving central wheels are located between them. 2. The transmission according to claim 1, characterized in that the gears of the driven wheel are made on disks that are connected to the driven shaft by means of a spline connection. 3. The transmission according to claim 1, characterized in that it is equipped with a floating ring resting on additional satellites, which has the same dimensions as the driving Central wheel, but is located on the other side of the supporting Central wheel.

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