JP4818535B2 - A transmission employing an eccentric oscillating internal meshing planetary gear structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission that employs an eccentric oscillation type intermeshing planetary gear structure used in industrial equipment, transportation equipment, and the like.
[0002]
[Prior art]
Conventionally, an eccentric body shaft having an eccentric body, an external tooth member rotatably attached to the eccentric body, an internal tooth member inscribed in mesh with the external tooth member, and at least one of the axial directions of the external tooth member And a carrier member connected to the outer tooth member via means for transmitting only the rotation component of the outer tooth member. A transmission is known.
[0003]
A conventional example of such a transmission is shown in FIG. Four eccentric bodies 104A, 104B and 104C having a phase difference of 120 ° are integrally formed on the eccentric body shaft 102 of the transmission 100 shown in FIG. External teeth members 106A, 106B, and 106C are attached to the eccentric bodies 104A, 104B, and 104C via bearings 105A, 105B, and 105C, respectively.
[0004]
The reason why the external teeth members are arranged in three rows is mainly to increase the transmission capacity, maintain the strength, and maintain the rotation balance.
[0005]
External teeth such as a trochoidal tooth profile and an arc tooth profile are provided on the outer periphery of the external tooth members 106A, 106B and 106C. An internal tooth member 108 is in mesh with the external teeth.
[0006]
The internal tooth member 108 is a pin-like member and is held by the first case member 110A so as to be easily rotated.
[0007]
A second case member 110B and a third case member 110C are connected in this order on the left side of the first case member 110A in the drawing. Further, the right side of the first case member 110A in the figure is closed by the fourth case member 110D.
[0008]
A plurality of inner roller holes 111A, 111B, and 111C are formed in the outer teeth members 106A, 106B, and 106C at appropriate intervals in the circumferential direction, and a plurality of inner rollers 112 and inner pins 114 are inserted therein.
[0009]
These inner pins 114 are connected to the carrier member 116. The carrier member 116 is disposed on one side of the outer teeth members 106A, 106B and 106C in the axial direction (the side opposite to the fourth case member 110D), and also serves as an inner ring of the carrier member bearing 118 which is a cross roller. The second case member 110B, which also serves as the outer ring of the carrier member bearing 118, and the third case member 110C are rotatably supported. A seal member 119 is provided in the gap between the carrier member 116 and the third case member 110C.
[0010]
The eccentric body shaft 102 is rotatably supported by the fourth case member 110D and the carrier member 116 via two eccentric body shaft bearings 120 and 122 disposed on both axial sides of the external tooth members 106A, 106B and 106C. ing.
[0011]
When the eccentric body shaft 102 makes one rotation, the eccentric bodies 104A, 104B, and 104C also make one rotation. The outer teeth members 106A, 106B, and 106C try to swing around the eccentric body shaft 102 by one rotation of the eccentric bodies 104A, 104B, and 104C, but the rotation of the outer teeth members 106A, 106B, and 106C is restricted by the inner teeth member 108. The outer tooth members 106A, 106B, and 106C revolve while rotating slightly while being inscribed in the inner tooth member 108.
[0012]
For example, when the number of teeth of the external tooth members 106A, 106B and 106C is N and the number of teeth of the internal tooth member 108 is N + 1, the difference in the number of teeth is 1. Therefore, every time the eccentric body shaft 102 rotates, the external tooth members 106 </ b> A, 106 </ b> B, and 106 </ b> C are shifted by one tooth with respect to the internal tooth member 108 integrated with the case member 110. That is, one rotation of the eccentric body shaft 102 is decelerated to -1 / N rotation of the external teeth members 106A, 106B, and 106C.
[0013]
The rotation of these external gear members 106A, 106B and 106C is such that the revolution component is absorbed by the gap between the inner roller holes 111A, 111B and 111C and the inner roller 112, and only the rotation component is absorbed by the carrier member 116 via the inner pin 114. Communicated.
[0014]
As a result, a speed reduction with a reduction ratio 1 / N or a speed change with an increase ratio N is realized between the eccentric body shaft 102 and the carrier member 116.
[0015]
It is also possible to provide a transmission in which the carrier member is fixed to increase / decrease speed between the eccentric body shaft and the internal gear member. Further, the eccentric body shaft is fixed to increase / decrease speed between the carrier member and the internal gear member. It can also be set as a transmission.
[0016]
In addition, due to the swinging rotation of the external teeth members 106A, 106B, and 106C, a reaction force in the radial direction acts on the eccentric body shaft 102 via the eccentric bodies 104A, 104B, and 104C, but the two eccentric body shaft bearings 120 and Since it is stably supported by both sides by 122, it does not become a problem.
[0017]
[Problems to be solved by the invention]
However, the eccentric shaft bearings 120 and 122 include the fourth case member 110D, the first case member 110A, the second case member 110B, the third case member 110C, the carrier member bearing 118, and the carrier member 116. Therefore, there is a problem that it is difficult to manage the mounting error of the other eccentric body shaft bearing with respect to one eccentric body shaft bearing.
[0018]
That is, since many members are interposed between the two eccentric body shaft bearings, manufacturing errors of these interposed members are accumulated, and as a result, a relative mounting error between the two eccentric body shaft bearings tends to increase.
[0019]
If the relative mounting error between the two eccentric body shaft bearings is large, the center of rotation of the eccentric body shaft is displaced, and as a result, this misalignment adversely affects the rotational performance.
[0020]
In order to reduce such an attachment error, it was necessary to process a member interposed between the two eccentric body shaft bearings with high accuracy. For this reason, there existed a problem that the manufacturing cost of the whole transmission became high.
[0021]
On the other hand, there is an idea that the relative mounting error can be reduced by increasing the mounting span of the two eccentric body shaft bearings. However, when the mounting span of the two eccentric body shaft bearings is increased, a new problem that the transmission becomes larger in the axial direction is caused.
[0022]
The present invention has been made in view of the above-described problems, and is a low-cost and compact eccentric oscillating inscribed type that can reduce the mounting error and suppress the deviation of the center of rotation of the eccentric body shaft. It is an object of the present invention to provide a transmission that employs a meshing planetary gear structure.
[0023]
[Means for Solving the Problems]
The present invention includes an eccentric body shaft having an eccentric member, an outer teeth member kicked rotatably attached to the eccentric body, an internal gear member inscribed meshing with the outer teeth member, the axial direction of the outer tooth member A carrier member that is disposed on one side of the external member and opposite to the side to which the motor is connected, and is connected to the external tooth member through means for transmitting only the rotation component of the external tooth member. In the transmission employing the eccentric oscillating type intermeshing planetary gear structure, the one side of the external tooth member in the axial direction on the eccentric body shaft is the opposite side to the side to which the motor is connected. to thereby form a bearing mounting portion extending before Symbol two eccentric shaft bearing between the carrier member and the bearing mounting portion placed side by side in the axial direction, decentering the previous SL eccentric body shaft of the two it has to be supported in a cantilever state only by the body axis bearing More, it is to achieve the above object.
[0024]
In this way, the two eccentric shaft bearings can be attached to only one carrier member, and the relative mounting error between the two eccentric shaft bearings can be greatly reduced.
[0025]
For example, when processing the carrier member, if the carrier member is chucked to the machine tool and the mounting portions of the two eccentric body shaft bearings are processed continuously without releasing the chuck, these mounting portions Can be matched with high accuracy, and the mounting error of the two eccentric body shaft bearings can be greatly reduced at low cost.
[0026]
The idea according to the present invention is at first glance contradictory to the above-mentioned idea of reducing the relative mounting error by increasing the span of the two eccentric body shaft bearings. However, rather than taking a large span with many parts in between, it is more accurate to arrange between single parts (even if the span itself is short). It has been confirmed by the inventors' tests that the effect is remarkable when the eccentric body shaft has a hollow structure with a large diameter. The present invention has been made based on this finding.
[0027]
A carrier member bearing that supports the carrier member is installed in a space that is sandwiched between a pair of planes that are perpendicular to the axial direction, passing through the ends of the two eccentric shaft bearings on the axially separated side. Also good.
[0028]
Here, “installing a carrier member bearing in a space sandwiched between a pair of planes” is not only installing the entire carrier member bearing in a space sandwiched between a pair of planes, It also includes installing a part in a space between a pair of planes.
[0029]
By doing so, the carrier member can be made compact in the axial direction, and the entire transmission can be made compact in the axial direction.
[0030]
In addition, as described above, the eccentric body shaft has a hollow structure, and the inner diameter of the eccentric body shaft is set to be 0.2 times or more the pitch circle diameter of the internal teeth of the internal gear member. Even in this case, according to the present invention, the deviation of the axis can be minimized.
[0031]
There is a strong demand for an eccentric body shaft having a hollow structure with a large diameter in various applications. In the configuration of the present invention, since the eccentric shaft bearing is provided only on one side of the axial direction of the external gear member, supporting the eccentric body shaft you acting reaction force from the external gear member in cantilever fashion However, since the eccentric body shaft is supported by a large eccentric body shaft bearing that inevitably increases as the outer diameter of the eccentric body shaft increases, the inner diameter of the hollow hole is, for example, Even if it is large and cantilevered, sufficient support rigidity of the eccentric body shaft can be ensured.
[0032]
In particular, in the case of a type having a large inner diameter such that the inner diameter of the eccentric body shaft is 0.3 times or more of the pitch circle diameter of the inner teeth of the internal gear member, it is very difficult to suppress the axial deviation satisfactorily with the conventional structure. However, according to the present invention, accurate assembly can be realized (by a large eccentric shaft bearing).
[0033]
By ensuring a sufficient support rigidity of the eccentric body shaft, it is possible to further reduce the rotational deflection of the eccentric body shaft. That is, if the present invention is applied to a transmission having such a hollow structure eccentric shaft, the great effect of the present invention can be expected.
[0034]
In addition, a case member provided with the inner tooth member is provided, the case member is formed into a cylindrical shape, and the carrier member is disposed only on one side in the axial direction of the outer tooth member, and on the other side. A ring plate-like seal member that closes a gap between the case member and the eccentric body shaft may be provided.
[0035]
By making the case member into a cylindrical shape that can be easily processed, the processing cost of the case member can be reduced. Further, according to the present invention, since the eccentric body shaft bearing is installed only on one side of the external tooth member in the axial direction, a highly rigid case member for supporting the eccentric body shaft is provided on the other side. There is no need. For this reason, the ring plate-shaped seal member having a simple structure with low rigidity can be used to seal and seal the gap between the case member and the eccentric body shaft, thereby making the transmission a simpler structure. The cost of the transmission can be reduced.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings.
[0037]
FIG. 1 is a side sectional view showing the overall structure of a transmission that employs an eccentric oscillating type intermeshing planetary gear structure according to a first example of an embodiment of the present invention.
[0038]
In the following description, parts that are the same as or similar to the configuration of the conventional example shown in FIG. 4 are given the same reference numerals as those in FIG.
[0039]
The eccentric body shaft 12 is formed with a bearing mounting portion 14 extending on one side in the axial direction of the external tooth members 106A, 106B and 106C, and a carrier member 16 is disposed on the one side.
[0040]
Two eccentric body shaft bearings 18A and 18B are installed side by side in the axial direction between the carrier member 16 and the bearing mounting portion 14, and the carrier member 16 is eccentric only by the two eccentric body shaft bearings 18A and 18B. The body axis 12 is supported.
[0041]
The eccentric body shaft 12 has a hollow structure, and the inner diameter of the eccentric body shaft 12 is about 0.36 times (more than 0.2 times) the pitch circle diameter of the internal gear member 108.
[0042]
Further, the eccentric body shaft 12 projects in the axial direction opposite to the bearing mounting portion 14, and can be connected to an external machine such as a motor at the projecting end portion 12A.
[0043]
The eccentric body shaft bearings 18A and 18B are arranged side by side in the axial direction so as to be separated from the external tooth member 106A in this order. These eccentric body shaft bearings 18A and 18B are ball bearings, and a seal member 20 is provided between the outer ring and the inner ring of the eccentric body shaft bearing 18B.
[0044]
The carrier member bearing 118 for supporting the carrier member 16 is a cross roller, and is in a space sandwiched between a pair of planes perpendicular to the axial direction through the ends of the two eccentric shaft bearings 18A and 18B on the axially separated side. The carrier member 16 is installed between the second case member 110B and the third case member 110C.
[0045]
The opposite side of the first case member 110 </ b> A from the second case member 110 </ b> B in the axial direction is closed by the fourth case member 22. The fourth case member 22 has a ring plate shape having a small inner diameter with respect to the fourth case member 110D in FIG. A seal member 24 is provided between the fourth case member 22 and the eccentric body shaft 12.
[0046]
Next, the operation of the transmission 10 will be described.
[0047]
Since the eccentric body shaft bearings 18A and 18B are mounted between the eccentric body shaft 12 and the one carrier member 16, the relative mounting error between these two eccentric body shaft bearings can be easily reduced.
[0048]
For example, when the carrier member 16 is processed, the carrier member 16 is chucked by a machine tool, and after the mounting portion of one eccentric body shaft bearing is processed, the other eccentric body shaft is continuously released without releasing the chuck. If the mounting portion of the bearing is machined, the shaft centers of the mounting portions of the two eccentric body shaft bearings can be matched with high accuracy.
[0049]
As a result, the relative mounting error of the two eccentric body shaft bearings attached to the carrier member 16 can be suppressed to a small level, and the rotational deflection of the eccentric body shaft 12 can be suppressed. Further, the processing of the carrier member 16 is easy, and the carrier member 16 can be processed at low cost.
[0050]
When the eccentric body shaft 12 makes one rotation, the eccentric bodies 104A, 104B, and 104C also make one rotation, and the external teeth members 106A, 106B, and 106C are engaged with the internal teeth member 108 while being restrained from rotating by the internal teeth member 108. While rotating.
[0051]
Only the rotational components of the swinging rotation of the external tooth members 106A, 106B and 106C are transmitted to the carrier member 16 from the inner roller holes 111A, 111B and 111C through the inner roller 112 and the inner pin 114.
[0052]
As a result, the rotation of the eccentric body shaft 12 is reduced to 1 / N and transmitted to the carrier member 16.
[0053]
Reaction force from the external tooth members 106A, 106B, and 106C acts on the eccentric body shaft 12 via the eccentric bodies 104A, 104B, and 104C. The eccentric body shaft 12 is supported in a cantilever manner on the carrier member 16 via two eccentric body shaft bearings 18A and 18B. The eccentric body shaft 12 is about 0.36 of the pitch circle diameter of the internal gear member 108. Since the hollow structure has a double inner diameter, the eccentric body shaft 12 has a large outer diameter. For this reason, the eccentric body shaft 12 has a high bending rigidity, and furthermore, since the rated loads of the two eccentric body shaft bearings 18A and 18B are large, the support rigidity of the eccentric body shaft is sufficiently ensured even in a cantilever state. Yes.
[0054]
Further, since the eccentric body shaft 12 has a hollow structure, it is lightweight despite having a large outer diameter. Further, if wiring or piping for an external machine such as a motor connected to the transmission 10 is inserted into the hollow hole of the eccentric body shaft 12, the combination of the transmission 10 and the external machine can be made compact. can do.
[0055]
Further, since the carrier member bearing 118 is installed in a space sandwiched between a pair of planes that pass through the axially separated ends of the two eccentric body shaft bearings 18A and 18B and is perpendicular to the axial direction. The second case member 110B, the third case member 110C, the carrier member bearing 118, the carrier member 16, the eccentric body shaft bearings 18A and 18B, and the eccentric body shaft 12 have high assembling rigidity, and these combinations are arranged in the axial direction. It is compact.
[0056]
Further, the inner periphery of the fourth case member 22 is also compact in the axial direction.
[0057]
In other words, the transmission 10 is a low-cost transmission that is compact in the axial direction and that can suppress the rotational deflection of the eccentric body shaft 12 to be small.
[0058]
Next, a second example of the embodiment of the present invention will be described.
[0059]
FIG. 2 is a side sectional view showing the overall structure of the transmission 30 according to the second example of the present embodiment.
[0060]
Two eccentric bodies 34A and 34B are integrally formed on the outer periphery of the eccentric body shaft 32 with a phase difference of 180 °. Two eccentric members 38A and 38B are rotatably attached to these eccentric bodies 34A and 34B via bearings 36A and 36B. An internal tooth member 40 is in mesh with the external tooth members 38A and 38B.
[0061]
A plurality of inner roller holes 44A and 44B are formed in the outer teeth members 38A and 38B at appropriate intervals in the circumferential direction, and the inner roller 46 and the inner pin 48 are inserted therein.
[0062]
The inner pin 48 protrudes on both sides in the axial direction of the outer teeth members 38A and 38B, and is fixed or fitted to the first carrier member 50 and the second carrier member 52 on each side.
[0063]
One end of the eccentric shaft 32 protrudes in the axial direction from the second carrier member 52 and can be connected to an external machine such as a motor. The other end of the eccentric body shaft 32 extends to one side in the axial direction of the external tooth members 38A and 38B, thereby forming a bearing mounting portion 54.
[0064]
Between the bearing mounting portion 54 and the first carrier member 50, two eccentric body shaft bearings 56A and 56B are installed side by side in the axial direction. The first carrier member 50 supports the eccentric body shaft 32 only by these two eccentric body shaft bearings 56A and 56B.
[0065]
A cylindrical second case member 58 is disposed on the radially outer side of the first carrier member 50. The second case member 58 is fastened integrally with the first case member 42 by a bolt 60.
[0066]
Between the second case member 58 and the first carrier member 50, two carrier member bearings 62A and 62B which are tapered roller bearings are installed side by side in the axial direction. The carrier member bearings 62A and 62B are disposed in a space sandwiched between a pair of planes that pass through the axially separated ends of the two eccentric body shaft bearings 56A and 56B and are perpendicular to the axial direction.
[0067]
An end plate 64 is attached to the end of the first carrier member 50, and the end plate 64 restricts the axial movement of the eccentric body shaft bearing 56B and the carrier member bearing 62B.
[0068]
A seal member 66 is provided between the end plate 64 and the second case member 58.
[0069]
A seal member 68 is provided between the second carrier member 52 and the first case member 42, and a seal member 70 is provided between the second carrier member 52 and the eccentric body shaft 32. .
[0070]
Next, the operation of the transmission 30 will be described.
[0071]
As in the transmission 10 according to the first example of the above-described embodiment, the transmission 30 has two carrier member bearings 56a and 56b attached to one carrier member 50, and the eccentric body shaft 32 is prevented from rotating. It is a low-cost, compact transmission (especially in the axial direction) that can be kept small.
[0072]
Further, since the transmission 30 includes the first and second carrier members 50 and 52, the carrier member and the external machine can be connected on either side in the axial direction. Further, since the first carrier member 50 is supported by two carrier member bearings 62A and 62B, which are a pair of tapered roller bearings, a large radial load or thrust load is applied to the carrier member by an external machine connected to the carrier member. Even when it acts, the carrier member can be stably supported.
[0073]
Next, a third example of the embodiment of the invention will be described.
[0074]
FIG. 3 is a side sectional view showing the overall structure of the transmission 70 according to the third example of the present embodiment.
[0075]
The transmission 70 is characterized in that a seal member 72 is provided instead of the fourth case member 22 with respect to the transmission 10 according to the first example of the embodiment. Since the other points are the same as those of the transmission 10, the same reference numerals as those in FIG.
[0076]
A ring-shaped protrusion 74A is formed at the end of the first case member 74 on the side away from the carrier member 16. Sealing member 72 is a ring-shaped body, projecting disposed between the raised portion 74A and the outer peripheral portion of the eccentric body shaft 12, closing the gap between the eccentric body shaft 12 and the first case member 74, and, It is sealed.
[0077]
The seal member 72 has a structure in which a general oil seal is extended radially outward.
[0078]
As described above, the gap between the first case member 74 and the eccentric body shaft 12 is formed without interposing another member such as an end face cover between the first case member 74 and the eccentric body shaft 12. Since the single seal member 72 is closed, the transmission 70 has a small number of parts, a simple structure, and a low cost.
[0079]
Although the rigidity of the seal member 72 is generally lower than when the end surface cover and the seal member close the space between the case member and the eccentric body shaft, the rotational deflection of the eccentric body shaft 12 is suppressed to a small level. The sealing member 72 can sufficiently maintain the airtightness between the first case member 74 and the eccentric body shaft 12.
[0080]
In the first to third examples of the embodiment, the eccentric body shaft has a hollow structure having a hollow hole of 0.2 times or more the pitch circle diameter of the inner teeth of the inner tooth member. In order to mount an eccentric shaft bearing with a sufficient load rating and to reduce the weight, it is preferable to use a hollow structure eccentric shaft having a hollow hole of 0.3 times or more the pitch circle diameter of the internal gear member. .
[0081]
On the other hand, when the radial load caused by the reaction force from the external tooth member acting on the eccentric body shaft and the reaction force by the external machine is small, the eccentricity has a hollow hole smaller than 0.2 times the pitch circle diameter of the internal tooth member. It may be a body axis.
[0082]
Further, it may be a solid structure eccentric shaft.
[0083]
Further, in the first to third examples of the above-described embodiment, the entire carrier member bearing is sandwiched between a pair of planes that pass through the ends of the two eccentric body shaft bearings on the axially separated side and are perpendicular to the axial direction. However, the present invention is not limited to this, and a part of the carrier member bearing may be installed in a space sandwiched between a pair of planes.
[0084]
Further, when the size of the transmission in the axial direction is not particularly problematic, a carrier member bearing may be installed outside the space sandwiched between the pair of planes.
[0085]
【Effect of the invention】
As described above, according to the present invention, it is possible to achieve an excellent effect that the eccentric body shaft can be rotated with high accuracy by reducing the deflection of the eccentric body shaft easily and at low cost. It is.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing an overall structure of a transmission according to a first example of an embodiment of the present invention. FIG. 2 is a side view showing an entire structure of a transmission according to a second example of an embodiment of the invention. FIG. 3 is a side sectional view showing an overall structure of a transmission according to a third example of an embodiment of the present invention. FIG. 4 is a side sectional view showing an entire structure of a conventional transmission.
10, 30, 70, 100 ... transmissions 12, 32, 102 ... eccentric shafts 14, 54 ... bearing mounting portions 16, 50, 52, 116 ... carrier members 18A, 18B, 56A, 56B, 120, 122
... Eccentric body shaft bearings 22, 110A, 110B, 110C, 110D ... Case members 34A, 34B, 104A, 104B, 104C ... Eccentric bodies 38A, 38B, 106A, 106B, 106C ... External teeth members 62A, 62B, 118 ... Carrier members Bearing 72 ... Seal member

Claims (4)

An eccentric body shaft having an eccentric body, an external tooth member rotatably attached to the eccentric body, an internal tooth member inscribed in mesh with the external tooth member, and one axial side of the external tooth member And a carrier member that is disposed on the opposite side to the side to which the motor is connected and is connected to the external tooth member via means for transmitting only the rotation component of the external tooth member. In a transmission that employs an intermeshing planetary gear structure,
The eccentric body shaft is formed with a bearing mounting portion extending on the one side of the external tooth member in the axial direction and opposite to the side to which the motor is connected , and the carrier member and the bearing two eccentric shaft bearing between the mounting portion and placed side by side in the axial direction, a pre-Symbol eccentric body shafts, characterized in that as supported by a cantilever state by only the two eccentric shaft bearing A transmission that employs an eccentric oscillating internal meshing planetary gear structure. In claim 1,
A carrier member bearing for supporting the carrier member;
An eccentric oscillating type intermeshing planetary gear characterized by being installed in a space sandwiched between a pair of planes perpendicular to the axial direction and passing through end portions on the axially separated sides of the two eccentric body shaft bearings A transmission that employs a structure. In claim 1 or 2,
The eccentric body shaft has a hollow structure, and the inner diameter of the eccentric body shaft is 0.2 times or more the pitch circle diameter of the inner teeth of the internal gear member. A transmission that employs a gear structure. In any of claims 1, 2 or 3,
A case member provided with the inner tooth member is provided, the case member is formed into a cylindrical shape, and the carrier member is disposed only on the one side in the axial direction of the outer tooth member, and on the other side. A transmission employing an eccentric oscillating internal meshing planetary gear structure characterized by comprising a ring plate-like seal member that closes a gap between the case member and the eccentric body shaft.

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