JPS6078155A - Reduction gear - Google Patents

Abstract

PURPOSE:To obtain a large reduction gear ratio without increasing the dimension of a reduction gear by forming grooves and a slit onto an input rotary shaft, supporting body, and an output rotary shaft so as to form each different angle and supporting a rolling body at the position where the above-described three members cross. CONSTITUTION:Grooves 3 and 13 and a slit 9 are formed onto an input rotary shaft 1, supporting body 11, and an output rotary shaft 8 so as to form each different angle, and a rolling body 14 is supported at the position where the above-described three members cross. Therefore, the reduction gear ratio can be set to an arbitray value according to the angle formed between the groove 3 of the input rotary 1 and the revolution center axis and the angle formed between the groove 13 of the supporting body 12 and the revolution center axis, and therefore, an exceedingly large reduction gear ratio can be obtained without increasing the dimension of the whole mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a reduction gear that can obtain a large reduction ratio while reducing the overall size.

[Technical background of the invention and its problems]

For example, many devices that use a motor as a power source transmit the rotation of the motor to a load via a reduction gear. Various reduction gears for such uses have been proposed in the past, but the most commonly used is a combination of small gears and large gears. T? It is a gear-type reducer in which a small gear is rotated by an input rotating shaft, and the rotation of a large gear meshed with the small gear is transmitted to the output rotating shaft.

However, gear type reducers have the following problems. That is, now, assuming that the number of teeth of the small gear is ''\21, the number of teeth of the large gear is Z21, the pitch circle diameter of the small gear is Dl, and the pitch circle diameter of the large gear is D2, the reduction ratio UU of this reducer is, and Therefore, in order to increase the reduction ratio u, it is necessary to reduce the pitch circle diameter Dt' of the small gear or increase the pitch circle diameter Dzw of the large gear.However, if the minimum number of teeth of the gear There is a limit, so in order to set a large reduction ratio U, it is necessary to increase the pitch diameter of the large gear, and as a result, the size of the entire reduction gear can be avoided. In addition, in a gear type reducer, power is transmitted through one or two teeth of the small gear and large gear that are in contact with each other. In order to transmit a large amount of power, it is necessary to set each tooth gear to a size that can withstand the transmission of that force. Therefore, from this point of view as well, if you try to set a large reduction ratio u7, you will not be able to avoid the overall problem. There was a problem that there was no.

[Object of the Invention] The present invention has been made in view of the above problems, and its purpose is to provide a reduction gear that can obtain a large reduction ratio without increasing the overall size. be.

[Summary of the invention]

The present invention is an input rotation shaft and this input rotation shaft! A cylindrical output rotating shaft that is rotatably supported internally and provided at the same time as the input, and a rolling element that transmits power between the two rotating shafts? A spiral groove extending in the axial direction is formed on the outer periphery of the input rotation shaft. A spiral groove is formed on the inner periphery of the support body at a predetermined angle with respect to the groove formed on the input rotation shaft, and a spiral groove is formed on the output rotation shaft at a predetermined angle with respect to the groove formed on the input rotation shaft. A slit is provided at an angle that intersects both grooves. A spherical rolling element is supported between these grooves and the slit in a freely movable manner, and the rolling element guided to one end of the slit is guided to the other end of the slit. An inox channel is formed on the support.

〔Effect of the invention〕

According to the present invention, the groove formed in the input rotation shaft, the groove formed in the support, and the slit provided in the output rotation shaft do not have different angles t, and the positions where these three intersect The rolling elements are supported by the Here, when the input rotation shaft starts a rotational movement 7 with respect to the support, the position where the input rotation shaft and the grooves formed in the support intersect moves in the axial direction and the circumferential direction. Along with this, the rolling elements supported at this intersecting position also move. If the angle between the moving direction of the rolling element and the longitudinal direction of the slit is not zero, the slit responds to the movement of the rolling element, and the output rotating shaft starts rotating Z. When the rolling element reaches its movable limit position, the rolling element enters the bypass path from one end of the bypass path, and crosses another rolling element from the other end of the bypass path. Since the rolling elements are always pushed out in the groove, the rotation of the output rotating shaft is performed continuously.In this case, the rotation speed of the output rotating shaft is equal to the moving direction of the rolling elements. and the slit, and this angle can be arbitrarily set by the angle formed by both the grooves formed in the input rotation shaft and the support body, and the angle of the slit. In the speed reducer configured as shown in FIG.

[Embodiments of the invention]

Hereinafter, details of the present invention will be explained based on illustrated embodiments.

1 and 2, reference numeral 1 in the figure indicates an input rotation shaft connected to a rotational drive source such as a motor (not shown) via a connecting shaft 2. A spiral groove 3 in the thread direction is formed. A cylindrical output rotation shaft 8 is rotatably supported on the input rotation shaft 1 via bearings 6 and 7 fixed to the handle parts 4 and 5. The output rotating shaft 8 has, for example, four slits 9 extending in the axial direction and equally spaced in the circumferential direction. These are the input rotating shaft 1 and the output rotating shaft 8.
is rotatably supported inside a cylindrical support body 120 via bearings 10 and 11, which are provided to sandwich the output rotation shaft between bearings 6 and 7. On the inner periphery of the support body 12, for example, there is a 1. A spiral groove 13 is formed in a so-called left-handed thread direction. A spherical rolling element 14 is provided at each intersection of the groove 3 formed in the input rotation shaft 1, the slit 9 provided in the output rotation shaft 8, and the groove 13 formed in the support body 12. However, the input rotating shaft 1. It is held in a state where it can freely roll with respect to the output rotation shaft 8 and the support body 12.

A bypass hole 15 is provided in the support body 12 at a position where the groove 3 and the groove 13 intersect, and especially at a portion where the axial position is the same as both ends of the slit 9, and which communicates these image portions. is the provision. The bypass hole 15 is filled with the rolling element 14, and as the input rotating shaft 1 and the output rotating shaft 8 move relative to the support 12, the rolling element 14 moves from the groove 3 to the groove 13 to the bypass hole. It is configured so that it can cycle through 15 times.

The operation of the reducer configured in this way will be explained in the third section below.
This will be explained with reference to the figures. That is, in FIG. 3, each groove 3, 1
3 and the slit 9, in which MI is the center line of the groove 3 formed in the input rotation shaft 1, and S is the center of the groove 13 formed in the support 12. line,
MO indicates the center line of the slit 9 of the output rotation shaft 8, respectively. In this state, the rolling element 14 is located at the intersection P of MI, S and MO.

Now, the input rotation shaft 1 moves by X with respect to the support 12,
If the center line of groove 3 changes from MI to MI', the intersection of groove 3 and groove 13 also changes from P.

Changes to. As a result, the rolling elements 14 also change from P to Q.
As a result, the slit 9 of the output rotation shaft 8 also moves to M.
Move by X from O to MO'.

In this case, the reduction ratio is set to be less than or equal to all.

In other words, the angle between the vertical direction in FIG. 3, that is, the direction orthogonal to the center lines MO, MO' of the slits 9, and the center lines MI, MI' of the grooves 3 is θ1. Same as above groove 13
Let θ2 be the angle formed with the center line S, and the distance between 29!
Then, the following formula holds true.

7-sin (π-θ, -θ2) -X ・sinθl
・・・・・・・・・・・・t(1) x=IbecosO,・・・・・・・・・(2) When formula (1) is rearranged for X, it becomes. Since it is the ratio between the reduction ratio uUX and X, it becomes.

Therefore, for example, θ, −45°, θ2=89.42
If it is set to 7°, the reduction ratio U will be 101.

When the output rotating shaft 8 rotates at this higher reduction ratio, the rolling element 14 eventually reaches the end of the slit 9. At this time,
As shown in FIGS. 1 and 2, the support body 12 is provided with a bypass hole 15, so the rolling element 14 enters into the bypass hole 15 from one end side. Bypass hole 1
5 is packed with rolling elements 14, so that another rolling element 14 is pushed out from the other end of the bypass hole 15 and inserted into the slit 9. By repeating the above, the blade rotating shaft 8 rotates continuously, and decelerated rotation in response to the rotation of the sword is realized.

In this way, according to this embodiment, the previous θ8. θ2° That is, the reduction ratio uY can be arbitrarily set depending on the angle formed by the groove 3 of the input rotation shaft 1 with respect to the rotation center axis and the angle formed by the groove 13 of the support body 12 with respect to the rotation center axis, so that the overall An extremely large reduction ratio can be obtained without increasing the size of the motor. In this case, since the grooves 3 and 13 are spiral grooves that advance in different directions, the frictional resistance between the rolling elements 14, the input rotating shaft 8, and the support body 12 is also small. .

Note that the present invention is not limited to the above embodiments.

For example, the relative angles between the grooves of the input rotating shaft, the grooves of the support, and the slits of the output rotating shaft, the positions and numbers of the slits and bypasses, etc. can be set completely arbitrarily. In short, the present invention can be implemented with various modifications without departing from the gist thereof.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway exploded perspective view of a reducer according to an embodiment of the present invention, Fig. 2 is a sectional view of the reducer, and Fig. 3 is for explaining the operation and reduction ratio Z of the reducer. This is a diagram. 1... Input rotating shaft, 2... Connection shaft, 3.13...
Groove, 6.7, 10.11... Bearing, 8... Output rotating shaft, 9... Slit, 12... Support, 14
...Rolling element, 15...Bypass hole. Applicant's agent Patent attorney Takehiko Suzue Figure 3

Claims (2)

[Claims] (1) An input rotating shaft ■ having a spiral groove extending in the axial direction formed on the outer circumference, is rotatably supported inside the input rotating shaft 2 and restricts movement of the input rotating shaft in the axial direction;
A cylindrical support body having a spiral groove formed at a predetermined angle with respect to the groove formed in the input rotation shaft on the inner periphery, and a rotatably provided between the input rotation shaft and the support body. and a cylindrical output rotation shaft provided with a slit at an angle that intersects both grooves formed in the input rotation shaft and the support body;
a plurality of spherical rolling elements rotatably supported at positions where the grooves formed on the input rotation shaft, the grooves formed on the output rotation shaft, and the slits intersect; and the slits provided on the support body. A speed reducer, characterized in that it is completely equipped with a bypass path that leads the rolling elements guided to one end of the slit to the other end of the slit. (2) The groove formed in the input rotation shaft and the groove formed in the support body are spiral grooves extending in mutually different directions in the axial direction. Reducer described in section.