JPS6118065B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a rolling planetary type reduction gear in which a planetary roller is rotatably disposed between an input shaft and an inscribed ring disposed coaxially with the input shaft; In particular, the present invention relates to a reduction gear that is capable of producing a differential output by using a plurality of planetary rollers having mutually different diameters.

[Background Art] In the case of a reduction gear using a rolling planetary mechanism, especially one using differential output, planetary rollers with different diameters and internal rings with different inner diameters are used. Skewing and thrust movements of the planetary rollers occur as unavoidable phenomena. In order to obtain smooth operation, it is essential to take measures against these movements in the skewing and thrust directions. For this reason, Mikiakiaki
In the device disclosed in Japanese Patent No. 53-136480, a configuration is used in which the position of the planetary roller in the thrust direction is determined by disposing thrust ball bearings between both axial end surfaces of the planetary roller and a carrier that supports the planetary roller. It is being However, with this configuration, the thrust ball bearing inevitably takes up a large amount of space, making it large in size, and the structure of the carrier is complicated because it must hold the thrust ball bearing. The problem was that the size of the image became large.

[Object of the Invention] The present invention has been made in view of the above points, and its object is to provide a reduction gear that is simple and compact in structure and has less torque loss.

[Disclosure of the Invention] Accordingly, the present invention provides an input shaft, a plurality of inscribed rings disposed coaxially with the input shaft and at least one of which is connected to an output transmission means, and a combination of the input shaft and the inscribed rings. a plurality of planetary rollers having different diameters, each supported by a carrier and inscribed in the inscribed ring and at least one circumscribed in the input shaft; and the output transmission of the inscribed rings arranged in the axial direction. A thrust bearing member that contacts both axial sides of an inscribed ring connected to the means is formed, and planetary rollers having different diameters and arranged in the axial direction are formed as an integrated body, and one inscribed ring and this It is characterized by providing an engaging part in the thrust direction between the planetary roller inscribed in the input shaft, and positioning in the thrust direction is performed by the inscribed ring that is greatly reduced in speed when viewed from the input shaft. Therefore, the torque loss is small, the thrust bearing member can be easily held, and since no force in the thrust direction is applied to the carrier, the structure is simple.

The present invention will be described in detail below based on the illustrated embodiment. In the figure, 1 is an input shaft serving as a sun roller, 2 is a planetary carrier, 3 is a planetary roller, and 4 and 5 are both inscribed rings. The input shaft 1, the carrier 2, and both internal rings 4 and 5 are arranged coaxially, and the shaft portions 31 at both ends of the planetary roller 3 are rotatably supported in the shaft hole 21 of the carrier 2, and the planetary roller 3 is connected to the input shaft 1 and the internal ring. Contact rings 4 and 5
A plurality of them are arranged at equal intervals around the axis of the input shaft 1. Each planetary roller 3 has an annular groove formed on its outer peripheral surface, so that both ends of the planetary roller 32 and boss 34 have the same diameter, and the space between these is the bottom of the groove. 33, a planetary roller 32 and a boss 34 are in contact with the input shaft 1, a planetary roller 32 is in contact with the inner circumferential surface of the inscribed ring 4, and a planet is in contact with the inner circumferential surface of the inscribed ring 5. Roller 32 makes contact. That is, the inner diameter of the inner ring 5 is smaller than that of the inner ring 4, and the outer diameter of the planetary roller 33 is smaller than that of the planetary roller 32. The shoulders of the planetary roller 32 and the boss 34, which are the opening edges of the concave grooves in the planetary roller 3, form a tapered surface 35 over the entire circumference, and both side edges of the inscribed ring 5 also correspond to this tapered surface 35. Tapered surface 1
It has become 5.

Output connecting rings 6 and 7 whose outer peripheral surfaces are shaped like gears are disposed on the outer peripheries of the inner rings 4 and 5, respectively. Both of these output connection rings 6 and 7 rotate integrally with the inscribed rings 4 and 5, respectively, and their integration is achieved by forming counterbores 17 on the outer peripheral surfaces of the inscribed rings 4 and 5, respectively. This is done by providing a counterbore 18 on the inner peripheral surface of each of the output connection rings 6 and 7, placing a steel ball 16 there, and caulking the periphery of the counterbore 18 or fixing the steel ball 16 with adhesive. ing. A washer 11 is a thrust bearing member disposed between the inner rings 4 and 5 arranged in the axial direction, and is made of a synthetic resin molded product with a small coefficient of friction. Further, 19 is a grip ring attached to both ends of the input shaft 1 where the planetary roller 3 is disposed, and 20 is a rolling bearing. The carrier 2 is formed by positioning two halves of the same shape with a positioning pin 22 and caulking them with a caulking pin 23.

Such a mechanism block is further housed in a pair of housings 8 and 9, as shown in FIG. 1, so that it can be put into practical use. Here, the housing 8 holds one rolling bearing 20 and has a washer 10 fixed thereon, which serves as a rotation guide surface for guiding the rotation of the internal ring 4.
The housing 9 holds the other rolling bearing 20 and has a washer 12 fixed thereon which serves as a rotation guide surface for guiding the rotation of the internal ring 5. These washers 10 and 12 are both formed as synthetic resin molded products with a small coefficient of friction, and are in sliding contact with the axial end surfaces of the inscribed rings 4 and 5, respectively, so that they are inserted in the thrust direction of the inscribed rings 4 and 5. receive. Note that both housings 8 and 9 are completely fixed in the thrust direction by screws or the like.

In this planetary reducer configured as described above, the inscribed rings 4 and 5 are attached by shrink fitting, so that each inscribed ring 4 and 5 connects to the planetary roller 3, the input shaft 1, and the planetary roller 3. A pressure contact force is applied between the two internal rings 4 and 5 to prevent slippage at each contact portion, and torque can be transmitted via lubricating oil. By fixing one of the inscribed rings 4 or 5 so that it cannot rotate, a rotational output with a large reduction ratio, which is a differential output, is extracted from the other inscribed ring 5 or 4. It is something that can be done. To explain this point based on FIG. 4, the diameter of the input shaft 1 is D ₁ , the diameter of the planetary roller 32 is D ₂ , the diameter of the planetary roller 33 is D ₃ , and the inner diameter of the inscribed ring 4 is
D ₄ , the inner diameter of the inscribed ring 5 is D ₅ , and a certain planetary roller 3 positions its center O 3 on this absolute tree X with a certain line X passing through the center O of the input shaft 1 as the absolute axis, and the planetary roller ₃ One point A on the outer periphery of the roller 32 is in contact with the input shaft 1, and as the input shaft 1 rotates through an angle θ ₁ , the planetary roller 3 moves to the position shown by the imaginary line in the figure, that is, O ₃ ' in the figure. When the center O ₃ moves to the position and the point A moves to the point A', ∠O ₃ OO ₃ ' is the revolution angle Θ of the planetary roller 3, ∠
OO ₃ 'A' is the rotation angle θ ₂ of the planetary roller 3, and if the inscribed rings 4 and 5 rotate by angles θ ₄ and θ ₅ , respectively, from the absolute axis X by contact with the planetary roller 3, then each If the contact is considered to be rolling transmission without slipping, the rolling contact distance between the input shaft 1 and the planetary roller 32 is equal to the rolling contact distance between the planetary roller 32 and the input shaft 1 (θ ₁ - Θ)D ₁ /2 = θ ₂ D ₂ /2 (θ ₁ - Θ) D ₁ = θ ₂ D ₂ ∴Θ = θ ₁ - θ ₂ D ₂ /D ₁ (i) On the other hand, the planetary rollers 32 and 33 and the inscribed ring 4,
5, the inscribed rings 4 and 5 are dragged by the revolution angle Θ of the planetary rollers 32 and 33 and rotate in the same direction as the revolution of the planetary roller 3, and the rotation angle of the planetary rollers 32 and 33 is θ ₂ . It is considered that each inscribed ring 4, 5 is sent and rotated in the opposite direction by the corresponding amount, and therefore, θ ₄ D ₄ /2 = −ΘD ₄ /2 + θ ₂ D ₂ /2 θ ₅ D ₅ /2=-ΘD ₅ /2+θ ₂ D ₃ /2 ∴θ ₄ =-Θ+θ ₂ D ₂ /D ₄ (ii) ∴θ ₅ =-Θ+θ ₂ D ₃ /D ₅ (iii) (ii) to (iii) Subtracting the formula, θ ₄ - θ ₅ = θ ₂ (D ₂ /D ₄ -D ₃ /D ₅ ) ∴θ ₂ = (θ ₄ - θ ₅ ) / (D ₂ /D ₄ -D ₃ /D ₅ ) (iv) Substituting equation (i) into equation (ii), θ ₄ =−(θ ₁ −θ ₂ D ₂ /D ₁ )+θ ₂ D ₂ /D ₄ =−θ ₁ +(D ₂ /D ₁ +D ₂ /D ₄ ) θ ₂ Substituting equation (iv) into this, θ ₄ = -θ ₁ + (D ₂ /D ₁ +D ₂ /D ₄ ) (θ ₄ -θ
₅ )/ _D2 / _D4 - _D3 / _D5 (v) Here, when the inscribed ring 4 is fixed so as not to rotate, _θ4 =0, so 0= _-θ1- ( _D2 /D ₁ +D ₂ /D ₄ )θ ₅ /D ₂ /
D ₄ −D ₃ /D ₅ ∴θ ₅ =−D ₂ /D ₄ −D ₃ /D ₅ /D ₂ /D ₁ +D ₂
/D ₄ θ ₁ (vi) Conversely, when the inscribed ring 5 is fixed so as not to rotate, θ ₅ =0, so the above equation (v) is θ ₄ =-θ ₁ +D ₂ /D ₁ +D ₂ /D ₄ /D ₂ /D ₄ −
D ₃ /D ₅ θ ₄ θ ₁ = (D ₂ /D ₁ +D ₂ /D ₄ /D ₂ /D ₄ −D ₃ /
D ₅ −1) θ ₄ =D ₂ /D ₁ +D ₃ /D ₅ /D ₂ /D ₄ −D ₃ /D ₅
θ ₄ ∴θ ₄ =D ₂ /D ₄ −D ₃ /D ₅ /D ₂ /D ₁ +D ₃ /
D ₅ θ ₁ (vii) By the way, if the rotation of the input shaft 1 is constant, these rotation angles θ ₁ , θ ₄ , and θ ₅ all indicate the rotation angle per unit time, that is, the angular velocity. Therefore, both equations (vi) and (vii) above are
This represents the speed ratio of the internal rings 5 and 4 relative to the speed ratio. As is clear from both equations, the rotation appearing in the inscribed ring 4 or 5 depends on the difference between the diameters D ₂ and D ₃ of the planetary rollers 32 and 33, and the inner diameter D of the inscribed rings 4 and 5. This is differential rotation caused by the difference between _D4 and _D5 , and the reduction ratio is extremely large. Further, depending on which of the inscribed rings 4 and 5 output is taken out, two outputs having different large reduction ratios can be selectively taken out.

On the other hand, the input shaft 1, the planetary roller 32, and the boss 34
The contact with is actually a cylindrical contact with unevenness, and since it receives pressure contact from the inscribed rings 4 and 5, this reducer also Since output torque is extracted, skewing is inevitable. Naturally, this skewing works to move the planetary roller 3 in the direction of the arrow in FIG. 1 even if torque is output from either of the internal rings 4 and 5 or even if the rotation of the input shaft 1 is reversed. Here, the washer 10 serving as a rotation guide surface in the housing 8, that is, as a thrust bearing member, sets the position of the inscribed ring 5 through the inscribed ring 4 and the washer 11, and the tapered surface 15 of the inscribed ring 5 The planetary roller 3 is prevented from moving in the direction of the arrow through the tapered surface 35 of the opening edge of the concave groove of the planetary roller 3. Reverse movement of the input shaft 1 caused by this reaction force is prevented by the rolling bearing 20 and the grip ring 19.

Washers 10, 11 and 12 are attached to the axial surface of the rotating inscribed ring 4 or 5.
Torque loss due to friction caused by sliding contact is caused by the fact that the friction coefficient of washers 10, 11, and 12 is small, and the rotation of inscribed rings 4 and 5 is greatly reduced when viewed from input shaft 1. Therefore, when considering the input shaft 1, it is very small. Further, as is clear from the above points, the carrier 2 is not subjected to thrust force at all, and furthermore, since the internal ring 5 and the concave groove of the planetary roller 3 have tapered surfaces 35 and 15, respectively, this In order to prevent the occurrence of differential sliding in the parts and jamming, the friction loss between the internal ring 5 and the planetary rollers 3 is small, and the rotation of the planetary rollers 3 is smooth. Moreover, since torque is transmitted by rolling transmission as a friction or traction drive, the power transmission efficiency is extremely good.

Note that the torque output from the inscribed ring 4 or 5 is transmitted to another mechanism from the output connection ring 6 or 7 attached to the outer circumferential surface of these rings. Alternatively, if the output is taken out only from the inscribed ring 5, the other inscribed ring 5 or 4 may be fixed in advance, and the output connection ring 7 or 6 may be omitted. Further, similar effects can be obtained by using a ball bearing as the thrust bearing member.

[Effects of the Invention] As described above, in the present invention, the thrust position of the planetary roller is determined by the thrust bearing member in contact with the inner ring via the inner ring, and the thrust bearing member is held by the carrier. In addition, since no force in the thrust direction is applied to the carrier, the structure of the carrier can be simple, and therefore it can be constructed compactly, and it can also be made compact. It also becomes easier to improve the division accuracy of the rollers. Also, since the internal ring is greatly decelerated when viewed from the input shaft, the torque loss between the internal ring and the thrust bearing member is extremely small considering the input, and does not pose a problem. Moreover, there are no noise problems.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of one embodiment of the present invention, Fig. 2 is a right side view of the same as above with the housing removed, and Fig.
The figure is a cutaway perspective view of the same as above with the housing removed, and FIG. 11 and 12 indicate washers as thrust bearing members.

Claims (1)

[Claims] 1. An input shaft, a plurality of inscribed rings disposed coaxially with the input shaft and at least one of which is connected to an output transmission means, and a carrier between the input shaft and the inscribed rings. a plurality of planetary rollers having mutually different diameters, each of which is supported and inscribed in each inscribed ring, and at least one of which is circumscribed to the input shaft; and one of the inscribed rings arranged in the axial direction is connected to the output transmission means. A thrust bearing member is in contact with both axial surfaces of an inscribed ring, and planetary rollers having different diameters and arranged in the axial direction are formed as an integral body.One inscribed ring and the planetary roller inscribed therein are A speed reducer characterized in that a thrust direction engaging portion is provided between the gears. 2. The thrust bearing member is held at the outer periphery of a pair of bottomed cylindrical housings that are centered around the input shaft via rolling bearings. Decelerator.