JP3034630B2 - 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 And a second shaft connected to the external gear through means for extracting only the rotation component of the external gear. Widely known.

FIGS. 3 and 4 show a concrete conventional example of this structure.
Shown in

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

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 ). Two external gears 5a, 5b are mounted on each eccentric body 3a, 3b in a double row via bearings 4a, 4b. The external gears 5a and 5b have inner roller holes 6a and 6b, respectively.
Are provided, 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.

External teeth 9 having a trochoid-type tooth shape (arc tooth shape when a cycloid part which is a special solution of trochoid is used) are provided on the outer periphery of the external gears 5a and 5b. The external teeth 9 are internally meshed with an internal gear 10 fixed to a casing 12. Specifically, the internal teeth of the internal gear 10 have a structure in which the outer pin 11 is loosely fitted in the outer pin hole 13 and held so as to be easily rotated.

The inner pin 7 penetrating the external gears 5a and 5b is fixed or fitted to the output shaft 2.

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,
The external gears 5a and 5b are oscillating about the input shaft 1. However, since the rotation of the external gears 5a and 5b is restricted by the internal gear 10, the external gears 5a and 5b Mostly only swinging is performed while touching.

For example, if the number of teeth of the external gears 5a and 5b 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, each time the input shaft 1 makes one rotation, the external gears 5a and 5b
It is shifted (rotated) by one tooth with respect to 0.
This means that one rotation of the input shaft 1 is -1 / of the external gears 5a, 5b.
It means that the rotation has been reduced to N rotations.

The rotation of the external gears 5a and 5b is absorbed by the gap between the inner roller holes 6a and 6b and the inner pin 7 (inner roller 8), and only the rotation component is reduced.
To the output shaft 2.

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 first shaft is used as the input shaft, the second shaft is used as the output shaft, and the internal gear is fixed.
The first shaft is an input shaft, the internal gear is an output shaft, and the second shaft is
The reduction gear can also be configured by fixing the shaft. Further, by changing the input and output shafts in these structures, a “speed increasing device” can be configured.

FIG. 5 shows an example in which the above structure is a unit type (Japanese Patent Laid-Open No. 62-2043).

In this structure, the output shaft 2 is attached to a counterpart engine through a bolt hole 14, but the internal meshing planetary gear structure itself is the same as that shown in FIGS. Therefore, members having the same functions as those in FIGS. 3 and 4 are denoted by the same reference numerals. The internal meshing planetary gear structure is also used in such types of speed reducers and speed-increasing gears.

In general, there is play in the gear transmission mechanism between the gears meshing with each other or the means for attaching to the 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 crash can be defined as an amount (angle) that allows one shaft (input shaft or output shaft) to be moved while the other is stopped. It does not indicate how much space there is.

In the transmission mechanism employing the double-row internal meshing planetary gear structure as described above, the play and play at the individual meshing portions interfere with each other, so that such an angle back 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.

Conventionally, in order to reduce the angle backlash, a method of increasing the processing accuracy of a part or selecting a combination of parts to be employed has been adopted.

In Japanese Unexamined Patent Publication (Kokai) No. 59-106744, etc., the eccentric body is divided corresponding to the external gear, and mounting means for mounting each eccentric body to a shaft is rotatable with respect to the shaft. There is disclosed a method of removing angular backlash in the normal rotation direction by one eccentric body while removing the same, and removing angular backlash in the reverse rotation direction by the other eccentric body.

[0023]

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.

In the method disclosed in Japanese Patent Application Laid-Open No. S59-106744, a plurality of external gears are provided to form a double row, so that the transmission capacity can be increased, the strength can be maintained, and the balance can be maintained. However, when rotating forward, power is transmitted only by the external gear that substantially eliminates backlash in the forward direction, and when reversely rotated, only by the external gear that eliminates angle backlash in the reverse direction. Since power transmission is performed, a new problem has arisen that the advantage of the double row as described above must be abandoned.

The present invention has been made in view of such a conventional problem, and has a simple structure capable of eliminating angle backlash and providing a plurality of external gears. It is an object of the present invention to provide an internally meshing planetary gear structure which does not lose its advantages.

[0027]

According to a first aspect of the present invention, there is provided a first shaft, an eccentric body rotated by the rotation of the first shaft, and an external gear mounted on the eccentric body and capable of eccentric rotation. A trochoid-type toothed inscribed body comprising: an internal gear internally meshed with the external gear; and a second shaft connected to the external gear via means for extracting only the rotation component of the external gear. In the planetary gear structure, the internal teeth of the internal gear are formed with an external pin hole and the external pin.
And an external pin that fits loosely into the internal gear hole.
A toothed element among the body the outer pin holes and outer pins unrealized sectional is a wedge-shaped, is divided radially into a base body located on the outer peripheral side, and, said outer pins, the internal teeth Every body,
The above object has been achieved by moving and pressing the base body and the external gear in a direction parallel to the axial direction of the internal gear to assemble them.

Further, the second invention provides a first shaft, an eccentric body rotated by the rotation of the first shaft, a plurality of external gears mounted on the eccentric body and capable of eccentric rotation, and External gear
To the inner contact mesh with internal gear, the external gear to the second shaft and the double row trochoid-based tooth profile inscribed type having a linked via means for extracting only rotational component of the external gear In the planetary gear structure, the internal teeth of the internal gear are formed with an external pin hole and the external pin.
And an external pin that fits loosely into the internal gear hole.
The body is radially divided into an internal tooth body including the external pin hole and the external pin , and a base body located on the outer peripheral side thereof, and the internal tooth body among them is made to correspond to the plurality of external gears. Further, the internal gear is divided in the axial direction to form a plurality of divided internal teeth having a wedge-shaped cross section. The above problem is also solved by moving and pressing in the direction parallel to the axial direction and assembling, and aligning the circumferential phase of each divided internal tooth body via the outer pin. is there.

[0029]

According to the first aspect of the present invention, the internal teeth of the internal gear are externally pinched.
And an outer pin that fits loosely into the outer pin hole.
Thus, the entire internal gear is radially divided into an internal tooth body including the external pin hole and the external pin and having a wedge-shaped cross section and a base body located on the outer peripheral side thereof. So
Then, the outer pin is assembled together with the wedge-shaped internal tooth body while moving and pressing between the base body and the external gear in a direction parallel to the axial direction of the internal gear.

As a result, the interval between the base body of the internal gear and the external gear is expanded by the wedge-shaped internal gear. Since the base body of the internal gear is stronger than the internal gear, the pitch circle of the internal gear portion of the internal gear is reduced as a result, and the outer pin moves toward the external gear (radially inward).
Translate in parallel . Here, the "internal teeth" of the internal gear
Since the `` pin '' does not bend but only translate,
The meshing with the gear does not decrease at all.

The distance between the internal gear and the external gear can be changed by adjusting the pressing force of the internal gear. Since the amount of angular backlash depends on this interval, pressing the internal tooth body until it contacts the external gear allows the angular backlash to be reduced to almost zero.

On the other hand, the second invention is intended to be applied mainly to a double-row internal gear type planetary gear structure having a plurality of external gears.

That is, according to the second aspect of the present invention, first, the internal gear is divided into an internal gear body including the internal gear portion and a base body located on the outer periphery thereof. At this time, the internal tooth body among them is further divided in the axial direction corresponding to the plurality of external gears, and as a result of the division, a plurality of divided internal tooth bodies having a wedge-shaped cross section are formed.

As a result, by moving and pressing each of the wedge-shaped divided internal teeth between the external gear and the base of the internal gear in a direction parallel to the axial direction of the internal gear,
The pitch circle of the internal tooth portion of the divided internal tooth body can be reduced.

In this case, when the external pins constituting the internal teeth of the internal gear are also divided in the axial direction corresponding to the external gear, the phase difference in the circumferential direction of each divided internal tooth body (external teeth) When there are two gears, there is no means for suppressing the shift of 180 ° when the number of gears is three, and 120 ° for three gears).
As a result, it may be difficult to maintain an accurate phase difference.

Therefore, in the second aspect of the present invention, the division of the outer pin is stopped, and the phase difference in the circumferential direction of each internal tooth body can always be accurately maintained by one outer pin. It is like that. In this case,
The "outer pin", which is the "inner tooth" of the internal gear, translates
And does not bend, so the meshing with the external gear
Does not drop at all.

As a result, it is possible to obtain an inscribed planetary gear structure free of angle backlash and always maintaining an accurate phase difference.

Further, since the transmission of the power is performed by the cooperation of the respective external gears in both the forward rotation and the reverse rotation, the advantage of the double-row type described above can be enjoyed as it is.

In both the first and second aspects of the present invention, the gap between the members is not reduced to zero by increasing the processing accuracy, so that the cost does not increase much and the assembly is relatively easy.

In addition, it is possible to form a state in which the internal gear and the external gear just come into contact with each other after absorbing manufacturing variations by adjusting the pressing force.

[0041]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
FIG. 2 is a diagram in which a configuration of a main part in FIG. 1 is clarified.

[0043] Conventionally, an internal gear, which has been integrated, the outer pin
The inner tooth body 110X including the inner tooth portion made of the pin 111 and a base body 110Y located on the outer peripheral side thereof are radially divided.

The internal tooth body 110X includes two external gears 1
05a and 105b, and are further divided in the axial direction.
Two divided internal teeth 110Xa and 110Xb are formed.

Each divided internal tooth body 110Xa, 110
Xb has a wedge-shaped cross section, and its short sides are arranged in directions facing each other.

Reference numeral 114 denotes a bolt for fixing the base 110Y of the internal gear 110 to the casing 112. By tightening the bolts 114, the divided internal gear bodies 110Xa and 110X
An axial pressing force is applied to each of Xb.

FIG. 2 shows a state in which the bottle 114 has not been tightened yet.

As is apparent from the figure, when the tightening is not performed, each of the divided internal teeth 110Xa and 110Xb protrudes by δ with respect to the axial length L of the base 110Y.

Here, when the bolt 114 is tightened,
Through the pressing surface 112a of the casing 112, the divided internal teeth 110Xa, 110Xb are separated from the external gears 105a, 105b.
And the base body 110Y are moved and pressed in a direction parallel to the axial direction of the internal gear. As a result, the divided internal teeth 110
Internal teeth of Xa, 110Xb (specifically, outer pin 111)
Pitch circle is reduced to the side of the external gears 105a and 105b.
Since they move in parallel and eventually come into contact with each other,
Stop the tightening.

As a result, there is no gap between the external gears 105a and 105b and the external pin 111 which is the internal gear of the internal gear, so that the angle backlash can be reduced to zero or almost zero. become.

Here, the outer pin 111 is not divided in the axial direction and is a single pin as in the prior art. Thus, the outer pin 111 is assembled while reducing the pitch circle of the divided internal tooth bodies 110Xa and 110Xb. Even if it does, the phase difference in the circumferential direction can always be maintained at a predetermined value (180 ° in this example), and the outer pin 111 itself is parallel.
Since it is moving and does not bend, it is possible to maintain a good rotational balance, and to reduce the external gear 1
05a and 105b .

Further, since the external pin 111 and the external gears 105a and 105b are brought into contact with each other by tightening the bolts 114, it is not required that the processing error itself of each member is so high, so that the manufacturing cost is reduced. Can be suppressed.

In addition, since the degree of contact at one end in the axial direction of the external gear 105a is loose due to the configuration, even if the dimensions of the members are not uniform due to the manufacturing process, the degree of contact is reduced. The presence of the lubricating side makes it possible to appropriately absorb this, and it is also possible to store a lubricating oil film on the warmed side.

As a result, as compared with a method of completely eliminating the gap between the external gear and the external pin by increasing the processing accuracy, it is possible to reduce the processing cost, reduce the transmission loss, and improve the durability. Become.

Further, since power is transmitted through the two external gears 105a and 105b in both the forward and reverse directions, the advantage of using two external gears, namely, an increase in transmission capacity,
Advantages such as maintaining strength and maintaining balance can be enjoyed without being reduced.

Since the construction and basic operation of the other parts are completely the same as those of the prior art, the same parts are denoted by the same reference numerals in the figures, and the repeated description is omitted.

In the above embodiment, the outer pins 11
Although no so-called outer roller is provided around 1, the present invention is obviously applicable to an internally meshing planetary gear structure using an outer roller.

[0058]

As described above, according to the present invention, while maintaining the basic advantages of the inscribed planetary gear structure,
An excellent effect that the angle backlash can be efficiently reduced with a low cost and simple configuration is obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a speed reducer to which a double-row trochoid-type inscribed planetary gear structure according to an embodiment of the present invention is applied.

FIG. 2 is a partial cross-sectional view showing a main part of FIG. 1 in an enlarged manner and its configuration clarified.

FIG. 3 is a sectional view showing a speed reducer to which a conventional double-row trochoid-type toothed inscribed planetary gear structure is applied.

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

FIG. 5 is a cross-sectional view showing an example in which a conventional double-row trochoid-type inscribed planetary gear structure is applied to another speed reducer.

[Explanation of symbols]

 1, 101: input shaft, 2, 102: output shaft, 3a, 3b, 103a, 103b: output shaft, 5a, 5b, 105a, 105b: external gear, 7, 107: inner pin, 8, 108a, 108b ... Internal roller, 10, 110: internal gear, 11, 111: external pin, 110X: internal tooth, 110Xa, 110Xb: divided internal tooth, 110Y: base.

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-type planetary gear structure comprising: an internal gear; and a second shaft connected to the external gear via means for extracting only a rotation component of the external gear. The inner teeth are loosely fitted in the outer pin hole and the outer pin hole
Together constitute at the outer pins, divides the entire internal gear and toothed element among the outer pin holes and outer pins unrealized section is a wedge shape, in the radial direction in the base body positioned on the outer peripheral side thereof, And moving the external pin together with the internal gear in a direction parallel to the axial direction of the internal gear between the base body and the external gear.
A trochoid-type inscribed planetary gear structure, which is assembled by pressing. 2. A first shaft, an eccentric body which is rotated by the rotation of the first shaft, and a plurality of external gears which are possible eccentric rotation mounted on the eccentric body, an inner contact to the external gear A double-row trochoid-type inscribed-type planetary gear structure comprising: an internal gear that meshes with a second shaft connected to the external gear via means for extracting only the rotation component of the external gear. In the above, the internal teeth of the internal gear are loosely fitted into the external pin hole and the external pin hole.
An internal gear including the external pin and the entire internal gear including the external pin hole and the external pin ;
The inner tooth body is divided in the radial direction into the base body located on the outer peripheral side thereof, and the inner tooth body is further divided in the axial direction in correspondence with the plurality of external gears. Forming a tooth body, moving and pressing each of the wedge-shaped divided internal tooth bodies in a direction parallel to the axial direction of the internal gear between the base body and the external gear, and assembling; A double-row trochoid-type inscribed planetary gear structure, wherein the phases of the divided internal teeth in the circumferential direction are aligned via the outer pins.