JPS62246658A - Pulley type differential speed reducer - Google Patents

Abstract

PURPOSE:To simplify both appearance and attachment and to reduce cost by axially supporting both a fixed shaft and an output shaft on a rotary shaft of a pulley, axially supporting a planetary shaft at a specified distance from the axial center of the pulley and revolting and rotating in link motion with the pulley, and arranging rotation transmitting elements between respective shafts. CONSTITUTION:When input rotation is given to a pulley 1, a planetary shaft 22 revolves over the circumferences of a fixed shaft 11 and an output shaft 19 in link motion with the pulley to form a turnaround shaft planetary gear mechanism by means of engagements between a gear 14 and a planetary gear 26, and between a planetary gear 28 and a gear 20. Here, if the number of teeth of respective gears are all the same, the output shaft 19 does not rotate even if rotation is inputted to the pulley 1. Also, the smaller the difference in the numbers of the teeth, the greater a speed reduction rate obtained. Making the entire structure of a pulley type in this way, appearance is made of a simple shape, attachment to a structure is made easy, and further arms for supporting the planetary shaft are made unnecessary to reduce cost.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pulley-type differential speed reducer.

(Prior art) Conventionally, a planetary gear mechanism with folded shafts as shown in Fig. 2 is well known as a mechanism for obtaining a large reduction ratio between the input shaft and the output shaft. There is a differential reducer shown in Figure 3.

Incidentally, in FIGS. 2 and 3, parts having the same functions are given the same reference numerals.

In this speed reduction mechanism, a gear (101) is fixed, and a planetary shaft (107) revolves through an arm (105) due to the rotation of a coaxial input shaft (106).
The planetary gear (102) that engages with the planetary shaft (101) rotates, and in conjunction with this rotation and revolution, the planetary gear (103) provided at the other end of the planetary shaft (107) rotates at one end of the output shaft (108). It rotates and revolves around the circumference of a gear (104) provided in the. At this time, the gear (104) rotates due to engagement with the planetary gear (103).

Therefore, the reduction ratio of the output shaft changes depending on the difference in the number of teeth from the gear (101) to the gear (104).

Now, gears (101), (104), planetary gears (102)
・If the number of teeth of (103) is a, b, c, and d, and the angular velocities of input shaft (106) and output shaft (108) are w0w, then w={1-a・c/(b・d) There is a relationship of }・w0.

Now, a=99, b=100, c=101, d=100
Then, w={1-99×101/(100×100)}×w0
=(1/10000)×w0, and a large reduction ratio can be obtained.

(Problem to be solved by the invention) However, in the above-mentioned reduction gear, the arm (1
05) is required, the mechanism becomes complicated, and the cost increases. In addition, the input shaft (106) and the output shaft (108) are separated from each other in the front and back, which is inconvenient when assembling it into a machine.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned drawbacks and to provide a reduction gear that is extremely simple in appearance and easy to install.

(Means for Solving the Problems) In order to solve the above problems, the present invention is configured as follows.

A fixed shaft and an output shaft are rotatably supported on the rotating shaft of the pulley, and a planetary shaft that can revolve and rotate in conjunction with the pulley is supported at a predetermined distance from the center of the shaft. , rotation transmitting elements that engage with each other are provided between the fixed shaft and the output shaft.

(Function) With the above configuration, when a rotational input is given to the pulley, the planetary shaft revolves in conjunction with it, so as shown in Figs. 2 and 3.
The arm (105) shown in the figure is not necessary, and since the rotational input is directly applied to the pulley, the transmission efficiency is also good. Furthermore, since the external frame (109) as shown in FIG. 3 is replaced with the pulley itself, the appearance is extremely simple and the installation is simple, simply by fixing the fixed shaft.

(Example) First, a first example of the present invention will be described based on FIG.

FIG. 1 shows a first embodiment of the present invention.

Ribs (2) and (6) are welded to the inner circumference of pulley (1), and flanges (3) and (7) are attached to bolts (4) and (8).
) to be installed. Also, a flange (5) is welded to an appropriate position between flanges (3) and (7). Flange (3
), and a fixed shaft (11) is provided via the bush (10).

One end of the shaft is prevented from rotating and is fixed to the structure (12) with a nut (13), and a gear (14) is fixed to the other end via a key (15). A boss (
17) and then connect the output shaft (1) via the bush (18).
9). The output shaft (19) is also rotatably supported by a ball bearing (16) provided at the center of the flange (5), and a gear (
20) is fixed, and gears, V-pulleys, sprockets, etc. are attached to the other end. Bush (24) fitted into boss (23) welded to appropriate position of flange (3)
A planetary shaft (22) is rotatably supported by a bush (25) provided on the flange (5) facing the bush. The shaft includes a planetary gear (26) that engages with the gear (14) via a key (27), and a key (29).
) is provided which engages the gear (20) via a planetary gear (28). Furthermore, a balance weight (40) is provided at a position substantially facing the planetary shaft (22) via a boss (41) so as to be bonded to the flange (5), thereby maintaining dynamic balance when the planetary shaft (22) revolves. Try to take it.

With the above configuration, when input rotation is applied to the pulley (1), the planetary shaft (22) rotates in conjunction with the pulley on the circumference of the fixed shaft (11) and the output shaft (19), and the gear ( 14) and the planetary gear (26), the engagement between the planetary gear (26) and the planetary gear (26)
8) forms a so-called folded shaft planetary gear mechanism.

Now, if the numbers of teeth of gears (14), (26), (28), and (20) are respectively Z14, Z26, Z28, and Z20, and the angular velocities of pulley (1) and output shaft (19) are w1 and w19, then , the following formula holds.

w19={1-Z28・Z14/(Z26・Z20)}
w1 Now, if the number of teeth of each gear is all the same, w19=0 from the above equation, and even if a rotational input is given to the pulley (1), the output shaft (19) will not rotate.

Also, if Z14=Z26, the above equation becomes w19=(1-Z28/Z20)・w1={(Z20-
Z28)/Z20}·w1, and it can be seen that the smaller the difference in the number of teeth, the larger the reduction ratio can be obtained.

Next, a second embodiment of the present invention will be described based on FIG. 4.

In the second embodiment, the rotation input to the pulley is decelerated in two stages and transmitted to the output shaft.

There are two flanges (5) inside the cylindrical pulley (51).
4) and (55), and a first output shaft (60) rotatable via a ball bearing is provided at the center thereof. Gears (66) and (67) are fixed to both ends of the shaft. Furthermore, a removable flange (53) is attached to the end of the pulley (51).
) and a rotatably fixed shaft (58) in its center.
will be established. One end of the shaft is fixed to another structure, and the other end is fixed to a gear (63). Furthermore, two flanges (53)
, (54), a rotatable planetary shaft (59) is provided at an appropriate position. Fixed to the shaft are planetary gears (64) and (65) that engage with the gears (63) and (66), respectively.

Next, a flange (56) is welded inside the pulley (52) and connected to one end of the pulley (51). That is, it has a detachable function that integrates the pulleys (51) and (52). Furthermore, a removable flange (57) is provided inside the pulley (52), and a second output shaft (6) is rotatably mounted together with the flange (56) via a ball bearing in the center.
2). Further, similarly to the planetary shaft (59), a rotatable planetary shaft (61) is provided at an appropriate position between the flanges (55) and (56), and a planetary gear (61) that engages with the gears (67) and (70) is provided. 68) and (69) are fixed. Furthermore, a balance weight (71) is provided substantially opposite the planetary shafts (59) and (61).

If configured as above, pulleys (51), (52)
When a rotational input is given to the gear (6), similarly to the first embodiment, the gear (6
3) to (66), the first output shaft (60) rotates at a reduced speed due to the folded shaft planetary gear mechanism. Furthermore, the gear (
67) to (70), the first output shaft (60) is further decelerated and rotational power is transmitted to the second output shaft (62).

Now, change the number of teeth of gears (63) to (70) to Z63 to
Z70, the angular velocity of pulleys (51) and (52) is w51
, the angular velocities of the first output shaft (60) and the second output shaft (62) are w60 and w62, then the following equation holds true.

w60={1-Z63・Z65/(Z64・Z66)}
w51w62={1-Z67・Z69/(Z68・Z6
8)} w60 Here, if the number of teeth of each gear is all the same, then from the above formula, w60 = w62 = 0, and the first output shaft (
60), the second output shaft (62) does not rotate.

Also, Z63=Z64, Z67=Z68, Z65=Z69
, Z66=Z70, then from the above formula, w62=(1-Z65/Z66)2・w51=((Z6
6-Z65)/Z66)2w51, and as in the first embodiment, the smaller the difference in the number of teeth, the greater the reduction ratio can be obtained.

Now, although the configurations of the first and second embodiments have been described above, they may be implemented as follows.

First, although the pulley, flange, etc. are of welded structure, casting may be used without limitation. Further, the rotation input to the pulley may be performed by inputting another rotation output directly to the pulley.

At this time, the outer peripheral surface of the pulley may be made uneven, or a rubber material may be wrapped around the pulley to prevent slippage. Further, rotation input may be applied by providing a rotation transmission element such as a V-pulley, gear, or sprocket on the circumference of the pulley or on the flange. Further, although gears are used to configure the folded shaft gear mechanism, the invention is not limited to this.
(including pulleys, toothed belt pulleys, etc.), sprockets driven by roller chain transmission, etc. may also be used. Further, although push and ball bearings are used as bearings for each shaft, sliding bearings and rolling bearings may be used as desired depending on the stress applied to the shaft, etc. In addition, in the flange that supports the fixed shaft, output shaft, or planetary shaft,
Although they are provided as shown in Figures 1 and 4, they are not limited to this, and any number of flanges, ribs, etc. can be placed at any location depending on the ease of assembly, the direction of each stress, the number of output shafts, planetary shafts, etc. All you have to do is install it and support it.

Although the planetary shaft is provided on the flange portion and revolves around the main shaft in the same direction and at the same angular speed as the pulley, it may also be provided with a rib inside the pulley.

Furthermore, even if an internal gear is fixed to the inner periphery of the pulley, a planetary gear is provided to sandwich it between the fixed shaft gear, and the planetary shaft is fixed inside, if the pulley rotates as described above, the planetary shaft will also be linked. It revolves around the earth. At this time, that is, when the internal gear is provided on the inner periphery of the pulley, the angular velocity of the planetary shaft is 1/2 of the angular velocity of the pulley.

At this time as well, it is sufficient to support the planetary shaft so that it can rotate.

In the second embodiment, the speed is reduced in two stages, but in three stages and four stages.
It is also possible to slow down in stages.

In other words, the number of output shafts and planetary shafts is equal to the number of reduction stages. It is not limited as it increases or decreases depending on the number.

The balance weight is provided opposite the planetary shaft, but it may be provided at any position as long as it does not interfere with the smooth rotation of the pulley, or may be omitted if unnecessary.

The fixed shaft has a rectangular cross section at the attachment part, and is tightened with a nut to prevent it from being pulled out, but there is no limitation as long as it has a non-rotatable structure.

(Effects of the Invention) As described above, by forming the entire device into a pulley type, the appearance becomes simple, it is easy to attach to a structure, and the applications are expanded.

Furthermore, an arm to support the planetary shaft is no longer required, which not only reduces costs, but also supports the flanges of the pulley to position the planetary shaft in a stress-effective position.Moreover, it can be easily assembled, and more than one can be arranged. However, it can be supported with an extremely simple structure.

As described above, the present invention can provide a reduction gear with extremely high practical value.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention. FIG. 2 is an explanatory diagram showing the main parts of a known folded-shaft planetary gear mechanism. FIG. 3 is a sectional view showing a conventional differential reduction gear. FIG. 4 is a sectional view showing a second embodiment of the present invention. (1) is a pulley, (3), (5), (7) are flanges, (11) is a fixed shaft, (19) is an output shaft, (22) is a planetary shaft, (14) and (20) are gears , (26)・(28)
is a planetary gear, and (40) is a balance weight. (51) is a pulley, (52) is a pulley, (53) ~
(57) is a flange, (58) is a fixed shaft, (59)
61) is the planetary shaft, (60) is the first output shaft, (62) is the second output shaft, (63), (66), (67), (70) are gears, (64), (65), (68) and (69) are planetary gears, and (71) is a balance weight.

Claims (1)

[Claims] (1) A fixed shaft and an output shaft are rotatably supported on the rotating shaft of the pulley, and a planetary shaft is supported at a predetermined distance from the center of the shaft so that it can revolve and rotate in conjunction with the pulley. and,
A pulley type differential speed reducer, characterized in that a rotation transmission element that engages with each other is provided between a fixed shaft and an output shaft.