JP3038027B2 - Trochoid tooth type inscribed planetary gear structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trochoid-type inscribed planetary gear structure particularly designed to reduce angular backlash.

[0002]

2. Description of the Related Art Conventionally, a first shaft, an eccentric body rotated by rotation of the first shaft, a trochoid-based external gear mounted on the eccentric body and capable of eccentric rotation, and the external gear A trochoid-type internal gear planetary gear structure, comprising: an internal gear internally meshed with the second gear; and a second shaft connected to the external gear via an internal pin for extracting only the rotation component of the external gear. Is widely known.

FIGS. 6 and 7 show a concrete conventional example of this structure.
Shown in

In this conventional example, the above-described structure is applied to a "reduction gear" by fixing the internal gear to the first shaft as an input shaft and the second shaft as an output shaft.

The input shaft 1 has a predetermined phase difference (18 in this example).
0 °), the eccentric bodies 3a and 3b are fitted. The eccentric bodies 3a and 3b are respectively connected to the input shaft 1 (center O ₁ ).
Is eccentric by the amount of eccentricity e (center O ₂ ). First and second external gears 5a, 5b are mounted on the eccentric bodies 3a, 3b in double rows via bearings 4a, 4b. The first and second external gears 5a and 5b are provided with a plurality of inner roller holes 6a and 6b, and the inner pin 7 and the inner roller 8 are loosely fitted.

The reason why the number of external gears is two (double row) is as follows.
This is mainly to increase transmission capacity, maintain strength, and maintain rotational balance.

The outer circumference of the first and second external gears 5a and 5b is provided with trochoid-type external teeth (arc teeth when a cycloid part which is a special solution of trochoid is used). These external teeth are in internal mesh with an internal gear 10 fixed to the casing 12. The internal gear of the internal gear 10 is
Specifically, the outer pin 11 is loosely fitted in the outer pin hole 13 and is held so as to be easily rotated.

An inner pin 7 penetrating the first and second external gears 5a and 5b is fixed or fitted to the output shaft 2.
Reference numeral 14 is a mounting bolt hole.

When the input shaft 1 makes one rotation, the eccentric bodies 3a, 3b
Rotates once. By one rotation of the eccentric bodies 3a and 3b,
Although the first and second external gears 5a and 5b try to oscillate around the input shaft 1, their rotation is restricted by the internal gear 10, so that the first and second external gears 5a and 5b 5b is
While only being inscribed in the internal gear 10, almost only swinging is performed.

Now, for example, the first and second external gears 5a, 5a
When the number of teeth of b is N and the number of teeth of the internal gear 10 is N + 1, the difference in the number of teeth is 1. Therefore, input shaft 1
The first and second external gears 5a and 5b are shifted (rotated) by one tooth with respect to the internal gear 10 fixed to the casing 12 for each rotation of. This means that one rotation of the input shaft 1 has been reduced to -1 / N rotation of the first and second external gears 5a and 5b.

The rotation of the first and second external gears 5a and 5b is absorbed by the gap between the inner roller holes 6a and 6b and the inner pin 7 (the inner roller 8), and only the rotation component is rotated. It is transmitted to the output shaft 2 via the pin 7.

As a result, a speed reduction of -1 / N is achieved.

The above-mentioned internal meshing planetary gear structure is currently applied to various reduction gears or speed-up gears. For example,
In the above structure, the speed reducer is configured such that the first shaft is the input shaft and the second shaft is the output shaft. However, the speed increaser is configured by changing the input and output shafts. You can also. Further, the output can be taken out from the internal gear by fixing the second shaft.

In general, in a gear transmission mechanism, there is play between the gears meshing with each other or the means for attaching to a shaft. For this reason, even if the driving side reverses when the rotation is changed from the normal rotation to the reverse rotation, the driven side does not appear to be reversed immediately.

In this specification, for the sake of convenience, such play or play that occurs when shifting from normal rotation to reverse rotation is referred to as "angle backlash". That is, the angle backlash indicates how much the input shaft is reversed and the output shaft is reversed accordingly. In other words, this angle backlash can also be defined as an amount (angle) by which one axis (input shaft or output shaft) can be moved while the other is stopped.

In the transmission mechanism employing the double-row internal meshing planetary gear structure as described above, play and play at the individual meshing portions interfere with each other. The rush is said to be relatively small.

However, even in such a double-row internal meshing planetary gear structure having a plurality of external gears, the transmission of force is originally performed by meshing the teeth. Although small when going from roll to reverse, angular backlash still occurs.

The existence of such an angle backlash is as follows.
When the transmission mechanism is used as a control device that involves forward and reverse rotation, it naturally causes a decrease in accuracy, and it is not preferable because impact tends to occur easily in view of the pure mechanical durability of the transmission device itself.

Hitherto, in order to reduce the angle backlash, a method has been adopted in which the processing accuracy of a component is increased or a component to be employed is selected and combined.

In Japanese Unexamined Patent Publication (Kokai) No. 59-106744, the eccentric body is divided in the axial direction corresponding to the two external gears, and mounting means for mounting each eccentric body to the shaft is provided on the shaft. The two eccentrics are displaced in the circumferential direction to assemble while forming a phase difference.One eccentric body eliminates the angle backlash in the normal rotation direction, and the other eccentric body rotates in the reverse rotation direction. A method for eliminating the angular backlash of U.S. Pat.

[0021]

However, the above-mentioned method of increasing the precision of the component has a disadvantage that the manufacturing cost is naturally increased.

Further, the method based on the selective combination of the parts to be assembled has a problem that the workability is extremely deteriorated because parts having a reduced gap are originally combined to reduce the angle backlash.

The method disclosed in Japanese Patent Application Laid-Open No. S59-106744 has a problem that it is difficult to adjust the angle backlash from the second shaft side (the second shaft is often used as an output shaft). Was. Also, utilizing the fact that each eccentric body is rotatable with respect to the axis, the eccentric body is mounted while giving a phase difference so that the external gear does not have angular backlash in the normal rotation direction and the reverse rotation direction. Therefore, the workability is extremely poor, and the "assembly phase difference" is loosened when the assembly is completed, which often results in a state where angular backlash can occur.

The present invention has been made in view of such a conventional problem, and the angle backlash can be easily adjusted from the side of the second shaft (output shaft). The object has been achieved by providing a trochoid-type inscribed planetary gear structure that can be easily performed.

[0025]

SUMMARY OF THE INVENTION The present invention provides a first shaft, an eccentric body rotated by rotation of the first shaft, an external gear mounted on the eccentric body and capable of eccentric rotation, and A trochoid-type tooth profile comprising: an internal gear internally meshed with the external gear; and a second shaft connected to the external gear via a plurality of internal pins for extracting only the rotation component of the external gear. In the tangential planetary gear structure, the second shaft is divided into two parts in the axial direction, and every other inner pin is connected to the second shaft located on the side of the external gear, and the remaining inner pin position A through-hole having a diameter slightly larger than the diameter of the inner pin is formed, and the remaining inner pins are connected to the second shaft located on the opposite side to the external gear through the through-hole. Pin Combined 2
The two second shafts are shifted in the circumferential direction to form an assembling phase difference.
The above problem is solved by connecting the two second axes.

Further, according to the present invention, a hole is formed in the second shaft located on the side of the external gear in the axial direction thereof, and the hole is formed in the second shaft located on the opposite side to the external gear. The screw hole is formed by slightly shifting the phase in the circumferential direction with respect to the portion, and a set screw having a conical tip is screwed into the hole from the side of the screw hole. This problem has been solved by reducing the circumferential phase shift between the hole and the hole, and forming the circumferential phase difference between the two second axes.

[0027]

In the present invention, the second shaft, which is often used as an output shaft, is divided into two in the axial direction, and every other inner pin is connected to the second shaft located on the side of the external gear. Moreover,
A through hole having a diameter slightly larger than the diameter of the inner pin is formed at a position corresponding to the remaining inner pin, and the remaining inner pin is coupled to the second shaft located on the opposite side to the external gear using the through hole. Like that.

As a result, the two second shafts can be assembled in the circumferential direction for every other inner pin to form a phase difference, so that there is no play in both the forward and reverse directions. State. Then, the two second axes are connected to each other without any play. As a result, operation without angle backlash in both the forward rotation direction and the reverse rotation direction can be performed.

In the second aspect of the present invention, the operation of connecting the two second shafts while the assembly phase difference is formed, that is, while maintaining a state in which there is no backlash in the normal rotation direction and the reverse rotation direction. But,
In view of the fact that it is quite difficult in practice, this is made easy to realize.

That is, a hole is formed in the second shaft located on the side of the external gear, and a screw hole is formed in the second shaft located on the opposite side to the external gear by slightly shifting the phase in the circumferential direction from the hole. To form
When a set screw having a conical tip is screwed in from the side of the screw hole, the phase shift between the screw hole and the hole is eliminated, and as a result, a phase difference is formed between the two second shafts. And maintain this state. Therefore, if the two second shafts are connected to each other in this state, the assembly phase difference formed at the time of the connection will not be loosened, and the set having no play in the normal rotation direction or the reverse rotation direction is surely formed. Can be attached.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIGS. 1 and 2, this embodiment uses a first axis as an input axis, a second axis as an output axis,
The present invention is applied to a "reduction gear" by fixing an internal gear to a casing.

In this embodiment, an input shaft (first shaft) 101
An eccentric body 103a rotated by the rotation of the input shaft;
103b and two rows of external gears (number of teeth N) attached to the eccentric bodies 103a and 103b and capable of eccentric rotation.
105a, 105b and the external gears 105a, 105b
The internal gear (number of teeth N + 1) 110 fixed to the casing 112 while being internally meshed with the external gear 105
a, 105b, eight inner pins 107X1 to 107X4 for taking out only the rotation components of the external gears 105a, 105b,
An output shaft (second shaft) 102 is connected through 107Y1 to 107Y4.

The output shaft 102 is divided into two in the axial direction and
02X, 102Y, and the inner pins 107X1 to
107X4 (every other) is connected.

In the output shaft 102X, through holes 102x1 to 102x4 having a diameter D2 slightly larger than the inner pin diameter D1 are formed at positions corresponding to the remaining inner pins 107Y1 to 107Y4.

On the other hand, the remaining inner pin 1 is attached to the output shaft 102Y located on the opposite side to the external gears 105a and 105b.
07Y1 to 107Y4 are inserted into the through holes 102x1 to 102x4.
Through. In this embodiment, the output shaft 102Y is further provided with through holes 102y1 to 102y4 corresponding to the inner pins 107X1 to 107X4.
107X4 are extended and loosely fitted.

This speed reducer is first temporarily assembled as in the conventional case. At this time, a temporary tightening bolt 125 is used. At this time, the processing of the fixing knock pin holes of the output shafts 102X and 102Y and the driving of the knock pin 122 are not performed. Here, the angle backlash is measured, and when it is necessary to further reduce the angle backlash, the temporary tightening bolt 125 is slightly loosened. And every other pin 107X
The two output shafts 102X and 102Y connected to 1 to 107X4 and 107Y1 to 107Y4 are displaced in the circumferential direction to form an assembling phase difference. Make it smaller.

When the two output shafts 102X and 102Y are displaced in the circumferential direction to form an assembly phase difference, a notch 124 is formed in the output shafts 102X and 102Y so that the work can be easily performed. I have.

In this state, after confirming the value of the angle backlash again, a trial operation is performed, the temporary tightening bolt 125 is further tightened, and the two output shafts 102X and 102Y are connected to each other by the knock pin 122.

Next, the operation of this embodiment will be described.

When the input shaft 101 rotates in the forward direction, the eccentric bodies 103a and 103b revolve (oscillate) in the forward direction.
As a result, the external gears 105a and 105b revolve (oscillate) in the normal rotation direction.

However, this external gear 105a, 1
05b is the internal gear 11 fixed to the casing 112.
Since the gear is meshed with 0, the meshing with the internal gear shifts by one tooth (difference in the number of teeth) by one revolution, and the shaft rotates by that amount. Conventionally, the revolving component is absorbed by the inner roller holes 106a and 106b and all the inner pins 107, and only the rotation component is transmitted to the output shaft 102. In this embodiment, the power is transmitted in the forward direction. Is performed, the rotation component is converted to the output shaft 102X (and 102Y) only by the inner pins 107X1 to 107X4 whose clearance in the normal rotation direction is made zero by the assembly phase difference.
Is transmitted to

On the other hand, in the case of power transmission in the reverse direction, the power transmission from the input shaft 101 to the external gears 105a and 105b is the same as in the conventional case, but the inner pin from which the clearance in the reverse direction is reduced to zero. The rotation components of the external gears 105a and 105b are transmitted to the output shaft 102Y (and 102X) by 107Y1 to 107Y4.

According to this embodiment, although the number of inner pins contributing to the transmission of power is reduced to half of that of the prior art, it is possible to rotate without any angular backlash in both the forward rotation direction and the reverse rotation direction. it can. Also, in order to prevent the occurrence of angle backlash, since the "gap" of each member is not eliminated by increasing the processing accuracy, the assembly operation itself can be easily performed almost in the same manner as before, or,
Since the predetermined gap itself remains even after assembly, machining errors and the like can be absorbed by this gap,
Lubricating oil and the like can be stored in this gap.

Next, a second embodiment of the present invention will be described with reference to FIGS.

In this embodiment, two output shafts 202X,
When the output shafts 202X and 202Y are coupled while forming an assembly phase difference by displacing 02Y in the circumferential direction, this work is devised so that this operation can be performed more easily and reliably.

That is, in the above embodiment, the output shaft 102X,
Temporarily tightening bolt 125 to shift 102Y in the circumferential direction
Is appropriately loosened to form an assembly phase difference, and the assembly phase difference is maintained by the operator by temporarily tightening the temporary fastening bolt 125 or the like.
It is necessary to fix X and 102Y to each other with knock pins 122. Therefore, in some cases, rattling may occur again during the trial operation or when the assembling phase difference formed at the time of knock pin driving is loosened and the assembling is completed.

Therefore, in order to prevent such a problem, in this embodiment, the output shaft 20 located on the external gear side is used.
A hole 230 is formed in the 2X in the axial direction (FIGS. 4 and 5). The hole 230 may be penetrated. Also, the output shaft 202Y located on the side opposite to the external gear
A screw hole 232 is formed by shifting the phase in the circumferential direction from the hole 230 by δ.

A set screw 234 having a conical tip can be screwed into the screw hole 232. That is, when the set screw 234 having a conical tip from the side of the screw hole 132 is screwed into the hole 230, the deviation δ between the screw hole 232 and the hole 230 is reduced (eliminated). As a result, an assembled phase difference is formed between the output shafts 202X and 202Y. The formed assembly phase difference can be adjusted by the screwing amount of the set screw 234.

That is, this screwing brings the inner pins 207X1 to 207X4 connected to the output shaft X into contact with each other in the normal rotation direction without any gap, and the inner pins 207Y1 to 207Y4 connected to the output shaft Y rotate in the reverse direction. The contact can be made without any gap in the direction. Then, in this state, the temporary tightening bolts 225 are further tightened, the value of the angle backlash is checked, and a slight test operation is performed. Processing is performed, and the angular backlash is maintained by driving the knock pin 222.

During this time, the assembly phase difference between the output shafts 202X and 202Y is reliably maintained by the set screw 234, so that the assembly phase difference is not loosened during the assembly or test operation. It is possible to obtain a structure that can reduce the angle backlash extremely simply and surely.

Since the other structure is the same as that of the previous embodiment, the same parts in the drawings are given the same reference numerals in the last two digits, and duplicate explanations are omitted.

[0053]

As described above, according to the present invention, the angle backlash can be drastically reduced while the dimensional accuracy of related parts is the same as that of the related art, and there is a slight variation between products. Even if there is, the angle backlash can be kept almost zero after absorbing this variation,
Furthermore, since the value of the backlash can be adjusted from the output shaft side in the temporarily assembled state, the effect that the efficiency of assembling is greatly improved can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a reduction gear to which a trochoid-type inscribed planetary gear structure according to an embodiment of the present invention is applied (FIG. 2I-);
It is sectional drawing (along line I).

FIG. 2 is a side view of the speed reducer as viewed from the direction of arrow II.

FIG. 3 is a side view corresponding to FIG. 2 showing a second embodiment of the present invention.

FIG. 4 is an enlarged sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a sectional view taken along line VV in FIG. 4;

FIG. 6 is a cross-sectional view showing an example of a speed reducer to which a conventional trochoid toothed inscribed planetary gear structure is applied.

FIG. 7 is a sectional view taken along line VII-VII of FIG. 6;

[Explanation of symbols]

1, 101, 201: input shaft, 2, 102X, 102Y, 202X, 202Y: output shaft, 3a, 3b, 103a, 103b, 203a, 203b
... Eccentric body, 5a, 5b, 105a, 105b, 205a, 205b
... External gears, 6a, 6b, 106a, 106b, 206a, 206b
... inner roller holes, 7, 107X1 to 107X4, 107Y1 to 107Y4
, 207X1 to 207X4, 207Y1 to 207Y4
... inner pin, 8, 108, 208 ... inner roller, 10, 110, 210 ... internal gear, 11, 111, 211 ... outer pin, 230 ... hole, 232 ... screw hole, 234 ... set screw.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16H 1/28-1/48 F16H 55/18

Claims (2)

(57) [Claims] A first shaft, an eccentric body rotated by rotation of the first shaft, an external gear mounted on the eccentric body and capable of eccentric rotation, and internally meshed with the external gear; A trochoid-type inscribed planetary gear structure comprising: an internal gear; and a second shaft connected to the external gear via a plurality of internal pins for taking out only the rotation component of the external gear. Second
The shaft is divided into two parts in the axial direction, and the second
The second shaft is connected to every other inner pin on the shaft, a through hole having a diameter slightly larger than the diameter of the inner pin is formed at a position corresponding to the remaining inner pin, and a second shaft located on the opposite side to the external gear. To
The remaining inner pins are connected through the through hole, and the two second shafts connected to the other inner pins are shifted in the circumferential direction to form an assembly phase difference in every other direction. A trochoid-type inscribed planetary gear structure, wherein the two second shafts are connected to each other without any backlash. 2. The device according to claim 1, wherein a hole is formed in the second shaft located on the side of the external gear, in the axial direction thereof, and the second shaft located on the side opposite to the external gear is provided with a hole. The screw hole is formed by slightly shifting the phase in the circumferential direction from the hole portion, and a set screw having a conical tip is screwed into the hole portion from the side of the screw hole, thereby forming the screw hole. A trochoid-type inscribed planetary gear structure, characterized in that the circumferential phase shift between a hole and a hole portion is reduced, and the circumferential phase difference is formed between two second shafts.