JPS60136659A - Speed reduction unit - Google Patents

Abstract

PURPOSE:To obtain a speed reduction unit which carries out smooth meshing and has a uniform internal stress, by forming an internal contact ring in such a shape that it has a narrow width at its outer peripheral side but has a wide width at its inner peripheral side which makes into contact with planet rollers, and as well by providing an output power transmitting gear at the narrow outer peripheral side thereof. CONSTITUTION:Each of both internal contact rings 4, 5 has a convex cross- sectioned shape, that is, its has a wide inner peripheral section and a narrow outer peripheral section, and as well the narrow section is integrally projected from the widthwise center of the wide outer peripheral surface. An output power transmitting gear 6 is formed in the outer peripheral section of the internal contact ring 4, and a hub 7 is formed in the inner peripheral section of the internal contact ring 5. Further internal stress in the internal contact ring 4 will not be concentrated to a part thereof, and the tooth width of the gear itself is so narrow that the gear meshing thereof is stably made.

Description

[Detailed Description of the Invention] [Technical Field 1] The present invention relates to a rolling planetary reduction gear in which a planetary roller is disposed in a rotatable manner between an input shaft and an inscribed ring disposed coaxially with the input shaft. It is.

[Background technology] In a reducer using a rolling planetary mechanism, contact pressure (preload force) must be applied between the internal ring and the planetary roller, and between the planetary roller and the input shaft, depending on the output torque. This may not be the case, but since this preload is easily applied without requiring any additional members, it is generally done by attaching an internal ring to the input shaft and the planetary roller by burning it off. By the way, in such a device, in order to extract the output from the inner ring, as shown in FIG. It is configured to transmit power to the load-side member.

Here, in the past, since the width of the inner ring 4 was the same on both the inner and outer circumferential sides, there was a problem that stress was concentrated at the bottom of the tooth groove of the gear 6 due to the notch effect, causing a crack C. ), and since the inner peripheral surface of the inscribed ring 4 is in contact with the planetary rollers, the width should be increased (
As a result, the tooth width of the gear 6 also becomes thicker, resulting in a problem in that the gears do not mesh smoothly with each other because their contact surfaces become unstable.

[Object of the Invention] The present invention has been made in view of the above points, and its purpose is to reduce the width of the inner circumference of the inscribed ring in order to maintain contact between the inscribed ring and the planetary roller. A reducer that does not struggle with increasing size, allows the gear formed on the outer circumference of the inner ring to mesh smoothly with other gears, and does not cause cranking of the inner ring. is to provide.

[Disclosure of the Invention 1 The present invention provides a reduction gear in which a planetary roller is disposed between an input shaft and an inscribed ring disposed coaxially with the human-powered shaft, the planetary roller being inscribed in the inscribed ring and circumscribed in the input shaft. , the inner ring has a convex cross-section with a narrow outer circumferential side and a wider inner circumferential side where the planetary roller contacts, and a gear for output transmission is formed on the narrow outer circumferential side. , the tooth width of the gear on the outer circumference of the inscribed ring can be set to an appropriate width for meshing, regardless of the width of the inner circumference side where the planetary roller is inscribed in the inscribed ring, and the internal stress is made uniform. It was designed to make it possible to

The present invention will be described in detail below based on an embodiment in which differential outputs can be taken out.
2 is a human-powered shaft serving as a sun roller, 2 is a planetary carrier, 3 is a planetary roller, and 4 and 5 are both inscribed rings. Human power axis 1
The carrier 2 and both inscribed 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 bearing holes 21 of the carrier 2, and the input shaft 1 and the inscribed rings 4
and 5, a plurality of them are arranged around the input shaft 1 at equal intervals. Each planetary roller 3 has an annular groove formed on its outer peripheral surface, so that one end thereof has the planetary roller 32, the other end has a boss 34 having the same diameter and narrow width as the planetary roller 32, and a space between them. A planetary roller 33 is located at the bottom of the concave groove, and a planetary roller 32 is located on the human-powered shaft 1.
and the boss 34 contact, and the planetary roller 32 comes into contact with the inner circumferential surface of the inscribed ring 4, and the planetary roller 33 comes into contact with the inner circumferential surface of the inscribed ring 5. 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, are
A tapered surface 35 is formed over the entire circumference, and grooves 41 are formed as grease reservoirs between both ends of the planetary roller 33 in the axial direction and the tapered surface 35.

Further, both side edges of the inscribed ring 5 also have tapered surfaces 15 corresponding to the tapered surfaces 35.

Both the inscribed ring 4 and the inscribed ring 5 have a convex cross-sectional shape, that is, the inner circumferential side is wide and the outer circumferential side is narrow, and the narrow part is integrally formed from the center in the width direction of the outer circumferential surface of the wide part. In the inscribed ring 4, the narrow outer periphery is used as a gear 6 serving as an output transmission member, and in the inscribed ring 5, the narrow outer periphery is used as a huff 7. A thrust bearing 11 is 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 and a steel ball. Further, 19 is a grip ring attached to both ends of a portion of the human-powered shaft 1 where the planetary roller 3 is disposed, and 25 is a rolling bearing. career 2
connects the same-shaped two-piece member 2O to multiple seven-piece pins 22.
It is formed by positioning the knock pins 22 and connecting and fixing them with vents 23 or bolts.

Such a mechanism block is further housed in a pair of housings 8 and 9, as shown in FIG. 2, so that it can be put into practical use. Here, the housing 8 has a fixed steel ring 10 that holds one rolling bearing 25 and serves as a rotation guide surface that guides the rotation of the internal ring 4 via a thrust bearing 11.
holds the Ikekata rolling bearing 25 and has a fixing surface for the internal ring 5. The inner ring 5 is completely fixed by bolts 38 which are fixed to this fixing surface through notches 37 in the hub 7 formed on the outer periphery of the inner ring 5. Further, the housing 9 also serves as a housing for the motor M which is directly connected to the human power shaft 1.

In the figure, 50 is the rotor of motor N4, 51 is the stator, and 52
53 is a bolt for fixing the stator, and 53 is a bolt for fixing the rotor 50 to the input shaft 1.
Nut for fixing to, 54 is a spring washer, 55
It is a motor cover, and 56 indicates a spacer for fixing the thrust. The gear 6 of the internal ring 4 meshes with the gear on the load side through cutouts formed in the housings 8 and 9.

In this planetary reducer configured as described above, the inscribed rings 4 and 5 are attached to the input shaft 1 and the planetary roller 3 by burning out, so that each inscribed ring 4 and 5 is attached to the planetary roller 3. and input shaft 1 and planetary roller 3
A preload force is applied between the input shaft and both internal rings 4 and 5 to prevent slippage at each contact portion, and to transmit torque via lubricating oil. Since the inscribed ring 5 is fixed, the rotational input from the inscribed ring 1 can be taken out as a rotational output with a large reduction ratio, which is a differential output from the other inscribed ring 4.

To explain this point based on FIG. 5, the input shaft 1
The diameter of the i-star roller 32 is D2, the diameter of the planetary roller 33 is D3, the inner diameter of the inscribed ring 4 is D5, the inner diameter of the inscribed ring 5 is D5, and it passes through the center O of the input shaft 1. With a certain line X as an absolute axis, a certain planetary roller 3 or its center O3 is positioned on this absolute axis X, and the planetary roller 32
One point A on the outer periphery of is in contact with the input shaft 1, and by rotation of the input shaft 1 at an angle θ1, the planetary roller 3 moves to the position shown by the imaginary line in the figure, that is, the center O3 moves to the position 031 in the figure. At the same time, 103○Ow1' when the point A moves to point A' is the revolution angle θ of the planetary roller 3, 1003
'A' is the rotation angle θ2 of the planetary roller 3, and the inscribed rings 4 and 5 are in contact with the planetary roller 3 at an angle θ4. If it rotates by θ5, and if each contact is considered to be a rolling transmission without slipping, then 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. Because (θ+ e) I) +/ 2 = 02D2/ 2(θ1
-θ)D1=θ2D2, . θ=θ1−θ2D2/D, (i) On the other hand, the planetary rollers 32, 33 and the inscribed ring 4. ．． 5, the inscribed rings 4 and 5 rotate in the same direction as the revolution of the planetary roller 3 by being dragged by the revolution angle e of the planetary roller 32.33, and the rotation angle θ2 of the planetary roller 32.33 It is considered that each inscribed ring 4.5 is sent and rotated in the opposite direction by the corresponding amount, and therefore θ, D4/2=-θD, /2+θ2D2/2θsDs/
2-1 θD, /2+θ2D3/2;, o, -10+62
D2/D+ (ii), °, θ, knee θ + θ2D =
/ D 5 (i i i ) From formula (11), (iii)
Subtracting the formula, θ4-θ, = θ2(D2/D4-D, /D,), °, θ
2-(θ, -〇,)/(D2/D4-D, /D9) (
iV) Substituting equation (i) into equation (ii), θ4=-(θ1-θ2D2/DI)+02D2/D4=
-〇, +(D2/D, +D2/D4) θ2 to this (iv
), we get 05 because the inscribed ring 5 is fixed here.
20, therefore, the above equation (v) is: By the way, these rotation angles θ1, θ4, and θ5 all represent the rotation angle per unit time, that is, the angular velocity, if the rotation of the input shaft 1 is constant. Therefore, the above equation (vi) expresses the speed ratio of the internal ring 4 to the input shaft 1. As is clear from the above equation, the rotation caused by the internal ring 4 is caused by the rotation caused by the planetary roller 32. 33 each diameter D2.
l), and each inner diameter of the inscribed rings 4 and 5, D5
This is differential rotation caused by the difference in speed, and the reduction ratio is extremely large.

Now, the gear 6 that meshes with the gear on the load side is 1. This is an internal ring 4 which is wide on the inner circumference side and narrow on the outer circumference side.
Since the gear 6 is provided in the narrow part of the outer peripheral part of the inner ring 4, the inner ring 4 has a wider width than the narrow part of the outer peripheral part where the gear 6 is provided. As shown in FIG. 6, a curved surface R can be provided at a part of the corner such as the boundary between the parts and the bottom of the gear 6, as shown in FIG. This makes it possible to homogenize the stress without concentrating it on one part. In addition, although the width of the inner circumferential surface that contacts the planetary roller 3 is wide, the tooth width of the gear 6 itself is narrow, so the meshing between this gear 6 and the gear on the load side is to ensure stable contact. This allows for smooth power transmission. Similarly, in the inner ring 5 in which the hub 7 is provided on the outer circumferential side and the hub 7 is fixed to the housing 9, the internal stress is not concentrated in one part.

[Effect of the invention 1 As described above, in the present invention, the planetary roller is inscribed on the inner peripheral surface, and the outer peripheral part where the gear of the inscribed ring is formed with the gear for output transmission is formed in the outer peripheral part. Since it is narrower than the circumference, it is possible to homogenize the internal stress in the inner ring by eliminating the notch effect, and prevent the occurrence of cranks. The meshing between the t-tooth gear and the gear of the load 1111j can also be made smooth.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a part of the internal ring in the conventional example, Fig. 2 is a longitudinal cross-sectional view of an embodiment of the present invention, Fig. 3 is a right side view of the same with the howsong removed, Fig. 4 is a cutaway perspective view of the same as above with the housing removed; FIG. 5 is an explanatory diagram of the same as above; FIG. 6 is a perspective view of a part of the internal ring as above; , 4 and 5 are internal rings, and 6 is a gear. Agent Patent Attorney Ishi 1) Chief Figure 7 Figure 3 Sufu Figure 4

Claims (1)

[Claims] (1) A speed reducer in which a planetary roller is arranged between an input shaft and an inscribed ring disposed coaxially with the input shaft, and the planetary roller is inscribed in the inscribed ring and circumscribed on the input shaft, and the inscribed ring is on the outer periphery. A speed reducer characterized in that it has a convex cross-section with a narrow side and a wide inner circumferential side where the planetary rollers contact, and a gear for output transmission is formed on the narrow outer circumferential side.