JP2011080521A - Sealing structure of reducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent leak of lubricant and reduce the loss of power transmission of a reduction gear. <P>SOLUTION: The seal structure 131 of a reducer G1 includes an input shaft (rotary shaft) 100 of a decelerating mechanism 135 and a relatively rotating member 120 which relatively rotates to the input shaft 100, and the inside and outside of the reducer G1 are partitioned through a first seal member 107 incorporated between the input shaft 100 and the relatively rotating member 120. First and second seal members 107, 109 are disposed on both sides across the decelerating mechanism 135 of the input shaft 100, the sliding tensing force of the first seal member 107 is lower than that of the second seal member 109, and lubricant absorbing members 121, 123 are disposed on the outer side of the reducer G1 beyond the first seal member 107. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a seal structure for a reduction gear.

  Patent Document 1 includes a speed reduction mechanism 1 as shown in FIG. 6, an input shaft 2 of the speed reduction mechanism 1, and relative rotation members 3 and 4 that rotate relative to the input shaft 2. There is disclosed a seal structure 7 of a speed reducer 8 that partitions the inside and the outside of the speed reducer 8 through seal members 5 and 6 incorporated between an input shaft 2 and relative rotation members 3 and 4.

  A seal member 5 is disposed on the input side of the input shaft 2 of the speed reducer 8, and a seal member 6 is disposed on the output side. Grease is injected into the reducer 8. These sealing members 5 and 6 have a sliding force that can completely seal the inside and the outside of the speed reducer 8 by themselves, forming a sealed space inside the speed reducer 8 and sealing grease. It has stopped.

JP2008-190683 (FIG. 1)

  Since the seal members 5 and 6 in such a seal structure form a sealed space for enclosing the lubricant, the input shaft is tightened with a strong pressure, which causes a loss of power transmission of the speed reducer.

  However, if the seal members 5 and 6 are not provided, a sealed space for enclosing the lubricant cannot be formed, and the leakage of the lubricant is induced.

  In order to solve the above-described problems, an object of the present invention is to prevent lubricant leakage and reduce power transmission loss of the reduction gear.

  The present invention includes a rotation shaft of a speed reduction mechanism, and a relative rotation member that rotates relative to the rotation shaft, and the reduction gear of the speed reducer via a seal member that is incorporated between the rotation shaft and the relative rotation member. A seal structure of a speed reducer that partitions the inside and the outside, wherein first and second seal members are disposed on both sides of the rotating shaft across the speed reduction mechanism, and the sliding tension force of the first seal member However, it is weaker than the sliding force of the second seal member, and the lubricant absorbing member is arranged on the outer side of the speed reducer with respect to the first seal member. Solved the problem.

  In the present invention, the first and second seal members are incorporated between the rotation shaft and the relative rotation member. Since the sliding tightening force of the first seal member is lower than at least the sliding tightening force of the second seal member and the lubricant absorbing member is disposed on the outside of the speed reducer of the first seal member, the speed is reduced. The loss of power transmission of the machine can be reduced, and the lubricant absorbing member is a lubricant that tends to flow out from the first seal member to the outside of the speed reducer, which may be caused by insufficient sliding tightness of the first seal member. The agent can be recovered and the lubricant can be prevented from leaking from the speed reducer to the external space.

  In particular, when the rotary shaft is a high-speed shaft that has a low torque and rotates at a higher rotational speed than the output shaft, the power transmission loss due to the strength (degree) of the sliding tension force that fastens the high-speed shaft of the first seal member. Therefore, the loss of power transmission of the reduction gear can be further reduced by reducing the sliding force of the first seal member.

  The present invention also includes a rotating shaft of a speed reducing mechanism and a relative rotating member that rotates relative to the rotating shaft, and the speed is reduced via a seal member that is incorporated between the rotating shaft and the relative rotating member. A reduction gear seal structure for partitioning the inside and the outside of the machine, wherein the seal member can completely seal the inside and the outside of the speed reducer by itself with respect to the rotary shaft or relative rotation member. It can also be regarded as a configuration in which the lubricant absorbing member is not disposed on the outer side of the speed reducer with respect to the seal member and does not have a sliding tension force. Even with this configuration, the sliding force for tightening the rotation shaft of the seal member is reduced, and the lubricant absorbing member is arranged on the outside of the speed reducer of the seal member, thereby reducing the power transmission loss of the speed reducer. The lubricant absorbing member can collect the lubricant that is about to flow out from the seal member to the outside of the speed reducer, and can prevent the lubricant from leaking from the speed reducer to the external space.

  Furthermore, the present invention includes a rotation shaft of a speed reduction mechanism and a relative rotation member that rotates relative to the rotation shaft, and is configured between the rotation shaft and the relative rotation member, and the inside and outside of the speed reducer A narrower portion is formed between the rotary shaft and the relative rotating member, and the lubricant is disposed on the outer side of the reducer with respect to the narrower portion. It can also be regarded as a configuration in which the absorbing member is arranged. According to this configuration, at least the seal member on one side of the rotating shaft is eliminated, and a narrow portion is formed between the rotating shaft and the relative rotating member, and the narrower portion is located on the outer side of the speed reducer. Since the lubricant absorbing member is arranged, the power transmission loss can be further reduced as compared with the above-described seal structure, and the outflow of the lubricant is suppressed by the narrow portion, and lubrication is started from the narrow portion. Even if the agent flows out, the lubricant absorbing member can recover the lubricant and further improve the function of preventing the lubricant from leaking from the speed reducer to the external space.

  Note that the concept of the “seal member” of the present invention is not limited to the “seal member” provided only to prevent the lubricant from leaking, but also to other peripheral members, to the original function of the member itself. In addition, the concept of “a seal portion of a specific member” to which a function of preventing the lubricant from leaking is added.

  The present invention can prevent leakage of the lubricant and reduce power transmission loss of the reduction gear.

The longitudinal cross-sectional view of the reduction gear to which the seal structure concerning an example of embodiment of this invention was applied Enlarged view shown by arrow II in FIG. The longitudinal cross-sectional view of the reduction gear to which the seal structure concerning an example of 2nd Embodiment was applied The longitudinal cross-sectional view of the reduction gear to which the seal structure concerning an example of 3rd Embodiment was applied The longitudinal cross-sectional view of the other reduction gear to which the seal structure concerning an example of embodiment of this invention was applied A longitudinal sectional view of a reduction gear to which a conventional seal structure is applied

  Hereinafter, an example of an embodiment of the present invention will be described in detail based on the drawings.

  FIG. 1 is a cross-sectional view of a reduction gear G1 to which an example of an embodiment of the present invention is applied. FIG. 2 is an enlarged view indicated by an arrow II in FIG.

  First, the outline of the reduction gear G1 will be described.

  The speed reducer G1 has an input shaft (rotary shaft) 100 that rotates faster than a flange body (relative rotating member) 120 (or casing 122) that functions as an output shaft of the speed reducer G1, and is rotated relative to the input shaft 100. Flange body 120, two eccentric bodies 102 and 104 formed integrally with the input shaft 100, two external gears 110 and 112 respectively incorporated in the eccentric bodies 102 and 104, and The external gears 110 and 112 are each provided with an eccentric oscillating speed reduction mechanism 135 having (one) internal gear 114 which is internally meshed with each other at the same time.

  The input shaft 100 includes a hollow portion 101 along the axial direction at the center portion in the radial direction. A cylindrical member 103 that rotates relative to the input shaft 100 in a non-contact manner is disposed inside the hollow portion 101 in the radial direction.

  The cylindrical member 103 has an output side of the input shaft 100 that is widened toward the end, and is fastened to the flange body 120 by bolts 111 and 113 on the output side. The cylindrical member 103 has a hollow portion 105 along the axial direction in the central portion in the radial direction. The hollow portion 105 can be used through a cable or the like (not shown).

  The eccentric phases of the eccentric bodies 102 and 104 formed integrally with the input shaft 100 are shifted by 180 degrees in the circumferential direction. Two bearings 106 and 108 are arranged on the outer circumference of each eccentric body 102 and 104 side by side in the axial direction.

  The internal teeth of the internal gear 114 are constituted by cylindrical outer pins 114A. The number of teeth of the internal gear 114 is set to be “1” more than the number of teeth of the external gears 110 and 112.

  Inner pin holes 110A and 112A are formed in the external gears 110 and 112, respectively, and the inner pin 116 loosely fits and penetrates the inner pin holes 110A and 112A. The motor side cover 118 is fixed to the casing 122 on the axially opposite load side of the external gear 110, and the flange body 120 is provided on both the input shaft 100 and the casing 122 on the axial load side of the external gear 112. It is arranged so that it can rotate freely.

  The inner pin 116 is integrated with the flange body 120.

  Reference numerals 124 and 126 are ball bearings that rotatably support the input shaft 100 and restrict the movement of the bearings 106 and 108 in the axial direction. Reference numeral 115 denotes a cross roller bearing.

  The reduction gear G1 has the above-described configuration, and can be taken out from the flange body 120 side after greatly reducing the rotation of the input shaft 100. It is also possible to change the design so that the deceleration output is taken out from the flange body 120 or the casing 122.

  Here, the seal structure 131 centering on the first seal member 107 will be described.

  First and second seal members 107 and 109 are disposed at both ends of the input shaft 100 (on both sides of the speed reduction mechanism 135), and a third seal member 117 is disposed between the flange body 120 and the casing 122. In the speed reduction mechanism 135, grease as a lubricant is sealed. Of the first to third seal members 107, 109, 117, the first seal member 107 is related to the seal structure according to the embodiment of the present invention.

  The first seal member 107 is made of an elastic member such as resin, and is incorporated between the input shaft 100 and the flange body (relative rotating member) 120 on the outer side (output side) of the ball bearing 126 in the axial direction. The inside of the machine G1 is partitioned from the outside. The first seal member 107 includes a first member 107T assembled to the flange body 120 and a second member 107U assembled to the input shaft 100. The first seal member 107 is configured to be M-shaped in the axial cross section as a whole. ing. The first and second members 107T and 107U of the first seal member 107 are not in contact with each other and have a slight gap (narrow portion) 153 at the center. As a result, the pressure loss of the grease passing through the gap 153 is increased, making it difficult for the grease to pass.

  The first seal member 107 does not have a sliding force (a force for tightening the shaft while sliding) that can completely seal the inside and the outside of the speed reducer G1 by itself with respect to the input shaft 100. . Specifically, the first member 107T of the first seal member 107 in the seal structure 131 is assembled on the flange body 120 side and rotates together with the flange body 120. On the other hand, the second member 107U is assembled on the input shaft 100 side and rotates together with the input shaft 100. Further, the first and second members 107T and 107U of the seal structure 131 are not in contact with each other.

  For this reason, the “sliding pressing force X1 for sealing” by the first seal member 107 is zero.

  The seal structure 131 has a labyrinth structure 160 on the speed reduction mechanism 135 side of lubricant absorbing members 121 and 123 described later. More specifically, the lubricant absorbing members 121 and 123 are decelerated at the speed reduction mechanism 135 side (inside the speed reducer G1) and the first seal member 107 is decelerated at the counter speed reduction mechanism side (the first seal member 107 is the boundary). The input shaft 100 and the flange body 120 face each other with a slight gap on the side opposite to the side where the mechanism 135 exists (external side of the speed reducer G1), so that the grease hardly passes between the two. A labyrinth structure 160 is formed.

  In the seal structure 131, the two lubricant absorbing members 121 and 123 are provided on the anti-deceleration mechanism side of the first seal member 107 (external side of the speed reducer G1). More specifically, one lubricant absorbing member 123 is attached to the cylindrical member 103 so as to have a gap between the input shaft (rotating shaft) 100 and the other lubricant absorbing member 121 is the cylindrical member. The lubricant absorbing member 123 and the lubricant absorbing member 121 are disposed along the axial direction by being attached to the input shaft 100 so as to have a gap between them (a member that is integral with the relative rotating member) 103.

  The second seal member 109 is disposed outside the ball bearing 124 in the axial direction (input side) and between the input shaft 100 and the motor side cover 118. The second seal member 109 includes a spring (biasing member) 109 </ b> S that biases the lip portion 109 </ b> R that is a part of the second seal member 109 against the input shaft 100. That is, the second seal member 109 has a sliding force Y1 that can completely seal the inside and the outside of the speed reducer G1 by itself, and the present invention is not applied thereto.

  In other words, this means that the sliding tension force X1 of the first seal member 107 disposed on the output side (one end side) of the input shaft 100 is the first one disposed on the input side (the other end side). This also means that it is weaker than the sliding tension force Y1 of the two seal members 109 (X1 <Y1).

  The third seal member 117 is attached to prevent grease for lubricating the cross roller bearing 115 from leaking to the outside. The third seal member 117 is also a seal member having a biasing member 117S, and has a sliding contact force Y2 that can completely seal the inside and the outside of the reduction gear G1 by itself. Therefore, the present invention is not applied to the third seal member 117.

Next, the operation of the seal structure 131 will be described.
When the grease that lubricates the speed reduction mechanism 135 in the speed reducer G1 is about to leak out from the clearance of the ball bearing 126 to the outside of the speed reducer G1, the seal structure 131 in the present embodiment operates as follows. To do.

  The leaked grease is first blocked by the first seal member 107 incorporated between the input shaft (rotating shaft) 100 and the flange body (relative rotating member) 120. That is, the first seal member 107 has only a very small gap (narrow portion) 153 between the first member 107T and the second member 107U. For this reason, the flow of grease is largely restricted by the presence of the first member 107T and the second member 107U (although the first seal member 107 alone does not provide a complete sealing function).

  The slight amount of grease that has passed through the gap 153 between the first member 107T and the second member 107U reaches the labyrinth structure 160 formed on the speed reduction mechanism 135 side (inside the speed reducer G1) of the lubricant absorbing members 121 and 123. . An input shaft (rotating shaft) 100 that is a member on one side forming the labyrinth structure 160 rotates at a very high speed. The flange member (relative rotating member) 120 and the cylindrical member (member integrated with the relative rotating member) 103, which are the other members forming the labyrinth structure 160, are greatly decelerated by the eccentric rocking type reduction mechanism 135. It is rotating very slowly at a high output rotation speed. Therefore, the relative rotational speed of the members (input shaft 100, flange body 120) facing each other to form the labyrinth structure 160 is very high. As a result, the grease almost loses its leakage pressure by the labyrinth structure 160 before reaching the lubricant absorbing members 121 and 123.

  Then, a very small amount of grease that has passed through the labyrinth structure 160 is completely adsorbed and captured by the lubricant absorbing members 121 and 123. That is, one lubricant absorbing member 123 is attached to the cylindrical member 103 so as to have a gap with the input shaft 100, and the other lubricant absorbing member 121 has a gap between the cylindrical member 103. As illustrated, the lubricant absorbing member 123 and the lubricant absorbing member 121 are attached to the input shaft 100 and disposed along the axial direction.

  According to this configuration, for example, when the speed reducer G1 is installed with the upper side in FIG. 1 set as the “upper side” when the speed reducer G1 is actually installed, the cylindrical member 103 side is disposed above the hollow portion 105. Grease accumulates, and grease accumulates on the input shaft 100 side below the hollow portion 105. For this reason, the grease on the upper side of the hollow portion 105 is absorbed by the lubrication absorbing member 123 (arranged on the cylindrical member 103 side), and the grease on the lower side of the reduction gear G1 is lubricated (arranged on the input shaft 100 side). It is absorbed by the agent absorbing member 121.

  Moreover, in the present embodiment, the cylindrical member 103 and the input shaft 100 have a large relative rotational speed. Therefore, it is possible to extremely effectively prevent the grease from leaking out of the reduction gear G1 beyond the lubricant absorbing members 121 and 123 (alternately disposed on the cylindrical member 103 and the input shaft 100). As a result, the seal structure 131 can ensure a sufficiently high sealing performance.

  Further, since the lubricant absorbing members 121 and 123 can be replaced simply by removing the cylindrical member 103 via the bolt 111, maintenance is also easy.

  On the other hand, since the input shaft 100 rotates at a high speed with a low torque, even if a slight sliding force is exerted on the power transmission efficiency, the first seal member 107 in the seal structure 131 is the first member. 107T is assembled on the flange body 120 side, and the second member 107U is assembled on the input shaft 100 side. For this reason, the first member 107T rotates together with the flange body 120, and the second member 107U rotates together with the input shaft 100. Moreover, both members 107T and 107U are not in contact with each other. Therefore, the “sliding pressing force X1 for sealing” by the first sealing member 107 is zero.

  In the labyrinth structure 160, the input shaft 100 and the flange body 120 or the input shaft 100 and the cylindrical member 103 are not in contact with each other. Furthermore, the lubricant absorbing members 121 and 123 are not in contact with each other because they have a gap, and do not slide. Further, there are gaps between the lubricant absorbing member 121 and the cylindrical member 103 and between the lubricant absorbing member 123 and the input shaft 100, and they do not slide. In short, in the seal structure 131, there is no sliding part that prevents the rotation of the rotating member (that causes power loss).

  Therefore, according to the present seal structure 131, it is possible to minimize power loss caused by sealing while ensuring sufficiently high sealing performance, and maintenance is easy.

  Next, another embodiment will be described.

  In the following description of the embodiments, members having the same or similar functions are denoted by the same reference numerals in the last two digits as those in the previous embodiment, and redundant descriptions are omitted.

  FIG. 3 shows a schematic cross-sectional view of the reduction gear G2 in which the seal structure 231 is incorporated.

  Hereinafter, a second embodiment shown in FIG. 3 will be described.

  The first seal member 207 in this embodiment has the same basic structure as the second seal member 209 (109), but a spring (biasing member) for biasing the lip portion 207R to the input shaft 200 ( The lip portion 209R of the second seal member 209 does not have a spring 209S that biases the input shaft 200. For this reason, also in this embodiment, the sliding force X2 of the first seal member 207 is weaker than the sliding force Y2 of the second seal member 209 (X2 <Y2).

  Since the first seal member 207 does not have a spring, the first seal member 207 does not have a sliding force that can completely seal the inside and the outside of the reduction gear G2 by itself with respect to the input shaft 200. More specifically, when the inner diameter of the first seal member 207 is d, the first seal member 207 is (sliding pressing force of the first seal member 207: X2) / (inner diameter of the first seal member 207 : The value of d) is less than 0.2 N / mm. However, since the first seal member 207 contacts and slides part of the first seal member 207 to the input shaft 200 and the flange body 220, the sliding tension force X2 (which was zero) in the previous embodiment. It is larger than the sliding force X1 of the first seal member 107 (X2> X1).

  Lubricant absorbing members 221 and 223 are disposed on the anti-deceleration mechanism side of the first seal member 207 (external side of the speed reducer G2). Specifically, as in the above embodiment, one lubricant absorbing member 223 is attached to the cylindrical member 203 so as to have a gap between the input shaft 200 and the other lubricant absorbing member 221 is a cylinder. The lubricant absorbing member 223 and the lubricant absorbing member 221 are disposed along the axial direction by being attached to the input shaft 200 so as to have a gap between the cylindrical member 203 and the like member 203.

  In this embodiment, since the sealing function of the first sealing member 207 is further enhanced, the sealing function of the entire sealing structure 231 is higher than the sealing function of the sealing structure 131 in the above-described embodiment, and the grease is less likely to leak. It has become.

  Also in this embodiment, the input shaft 200 and the flange body 220 form a narrow portion 253, and the input shaft 200 (the tip portion in the axial direction) and the cylindrical member 203 (a portion that expands radially). A narrow portion 255 is formed. These narrow portions 253 and 255 constitute a labyrinth structure 260 that makes it difficult for grease to flow out from the inside of the reduction gear G2 to the external space.

  As a result, the leakage of the lubricant from the inside of the reduction gear G2 to the external space can be further prevented as compared with the previous embodiment, and the power transmission loss of the reduction gear G2 can be reduced as compared with the prior art.

  In the seal structure 331 in the third embodiment shown in FIG. 4, unlike the above-described embodiment, the seal structure 331 does not have an independent first seal member, and the bearing 326 itself that supports the input shaft 300 is a seal bearing. . That is, the seal member in the present embodiment is a seal piece (not shown) disposed in the seal bearing 326.

  Also in the present embodiment, the seal piece (first seal member) of the seal bearing 326 is alone with respect to the input shaft 300 (the inner ring 326A of the bearing 326 integrated with the input shaft 300). It does not have a sliding force that can completely seal In other words, the sliding contact force X3 of the seal piece (first seal member) of the seal bearing 326 is weaker than the sliding contact force Y3 of the second seal member 309 (X3 <Y3).

  Further, lubricant absorbing members 321 and 323 are arranged on the side of the seal bearing 326 opposite to the speed reduction mechanism. Specifically, as in the above embodiment, one lubricant absorbing member 323 is attached to the tubular member 303 so as to have a gap between the input shaft 300 and the other lubricant absorbing member 321 is It is attached to the input shaft 300 so as to have a gap between the cylindrical member 303 and the lubricant absorbing member 323 and the lubricant absorbing member 321 are disposed along the axial direction.

  Further, also in this embodiment, the input shaft 300 and the flange body 320 form a narrow portion 353, and the input shaft 300 (a tip portion in the axial direction) and the cylindrical member 303 (a portion that expands radially). The narrow portion 355 is formed. These narrow portions 353 and 355 constitute a labyrinth structure 360 that makes it difficult for grease to flow out from the inside of the reduction gear G3 to the external space.

  As a result, the leakage of the lubricant from the inside of the reduction gear G3 to the external space can be prevented, and the power transmission loss of the reduction gear G3 can be reduced.

  Moreover, since it is not necessary to provide a space for arranging the seal member exclusively, the reduction gear G3 can be made compact by that amount, and the cutting process for securing the space (in the flange body 320) can be achieved. Therefore, the strength of the flange body 320 can be increased and the processing cost of the flange body 320 can be reduced.

  The speed reducers G1 to G3 using the above embodiment are not necessarily limited to the speed reducer to which the above embodiment is applied, and may be used for other speed reducers.

  The speed reducer G4 in the embodiment shown in FIG. 5 includes a so-called sorting type inscribed mesh planetary gear type speed reducing mechanism 435.

  A pinion 437 is formed at the tip of a motor shaft 436 of a motor (not shown). The pinion 437 is meshed with an input gear 439 fixed to the input shaft 441.

  In the middle of the input shaft 441 in the axial direction, an input shaft gear 443 is formed integrally with the input shaft 441. The input shaft gear 443 meshes with the sorting gear 445. The sorting gear 445 is supported by an intermediate shaft (rotary shaft in the present embodiment) 400 via rollers 465. The distribution gear 445 meshes with an eccentric body shaft gear 449 formed on three eccentric body shafts 447 (only one is shown). Eccentric bodies 402 and 404 are formed integrally with the eccentric body shaft 447 on both sides in the axial direction of the eccentric body shaft gear 449.

  Two external gears 410 and 412 are incorporated in the two eccentric bodies 402 and 404, respectively. The external gears 410 and 412 are in mesh with the (one) internal gear 414. The number of teeth of the internal gear 414 is set by “1” more than the number of teeth of the external gears 410 and 412.

  The input shaft 441 is rotatably supported with respect to the flange body 420 and the output side flange body 451 via bearings 461 and 463, and the eccentric body shaft 447 is supported via bearings 467 and 469. The intermediate shaft 400 is press-fitted and fixed to the output side flange body 451.

  The rotation of the motor shaft 436 of the motor (not shown) is transmitted to the input gear 439 via the pinion 437. As the input shaft gear 443 rotates, the input shaft 441 to which the input shaft gear 443 is fixed rotates. As the input shaft gear 443 formed on the input shaft 441 rotates, the sorting gear 445 meshed with the input shaft gear 443 also rotates relative to the intermediate shaft 400 via the rollers 465. Since the sorting gear 445 meshes with the eccentric body shaft gear 449, the eccentric body shaft 447 on which the eccentric body shaft gear 449 is formed rotates. When the eccentric bodies 402 and 404 formed on the eccentric body shafts 447 are eccentrically rotated, the external gears 410 and 412 fitted to the eccentric bodies 402 and 404 are oscillated and rotated. Since the external gears 410 and 412 mesh with the internal gear 414 having a slight difference in the number of teeth, the external gears 410 and 412 rotate only slightly while rotating slightly. At this time, since the shaft center of the eccentric body shaft 447 is not oscillated, a slight rotation component of the external gears 410 and 412 is revolved around the input shaft 441 of the eccentric body shaft 447 as an output side flange body 451. Is transmitted to. At this time, the intermediate shaft 400 press-fitted and fixed to the output side flange body 451 also rotates at the same rotational speed as the output side flange body 451.

  The seal structure 431 of the speed reducer G4 according to the present embodiment is configured between the intermediate shaft 400 and the casing 422 and the like, and partitions the inside and the outside of the speed reducer G4. The seal structure 431 has only a narrow portion 454 between the intermediate shaft 400 and the casing 422 on one end side of the intermediate shaft 400, and no seal member is particularly disposed.

  The narrow portion 454, and the gap 455 between the intermediate shaft 400 (the tip portion in the axial direction) and the cylindrical member 403 (the portion spreading radially) are closer to the speed reduction mechanism 435 side (the speed reducer G4) than the lubricant absorbing members 421 and 423. The labyrinth structure 460 is configured on the inner side). This makes it difficult for the grease to reach the lubricant absorbents 421 and 423.

  However, since the narrow portion 454 and the gap 455 naturally do not have a sliding force that can completely seal the inside and the outside of the speed reducer G4 by themselves, the anti-reduction mechanism of the narrow portion 454 is not provided. Lubricant absorbing members 421 and 423 are disposed on the side (the outside of the speed reducer G4).

  As described above, in the present invention, it is not always necessary to arrange the seal member, and only the narrow portion may be formed. Of course, you may have both a sealing member and a narrow part like previous embodiment. Further, when there is a seal member, the narrow portion is not necessarily required. In any case, only the narrow portion of the seal member (and / or) does not have a function of completely sealing the inside and outside of the reduction gear, and the transmission loss of the reduction gear is reduced accordingly. Then, in combination with the presence of the lubricant absorbing member, the lubricant is completely prevented from leaking from the inside of the reduction gear to the external space.

  In the present invention, the structure of the speed reducer is not limited to the structure of the speed reducer described above, and can be incorporated in a speed reducer having another structure. The speed reducer may not have a hollow portion and may not have a labyrinth structure.

  Further, according to the present invention, for example, the motor shaft and the rotating shaft have a first pulley and a second pulley, respectively, and a timing belt is stretched around these first and second pulleys, and the first pulley The present invention can be applied to a reduction gear including a friction transmission type first-stage speed reducer that transmits rotational power from the first pulley to a second pulley and a gear transmission type rear-stage speed reducer. In this type of reducer, for example, in order to prevent the grease enclosed in the latter reducer from leaking to the former reducer side (different types of grease), the inside of the latter reducer When the present invention is applied to a seal structure of a speed reducer that partitions the motor from the outside, a seal member is disposed between the rotation shaft and the relative rotation member of the subsequent speed reducer, and the seal member is connected to the rotation shaft or the relative rotation member. The rotating member does not have a sliding tension force that can completely seal the inside and the outside of the subsequent reduction gear by itself, and the outer side of the subsequent reduction device from the sealing member ( That is, the lubricant absorbing member may be arranged on the speed reducer side in the previous stage.

  In addition, the seal structure according to the present invention may be applied to the front reduction gear (in order to prevent the grease of the front reduction gear from leaking to the rear reduction gear). In this case, a seal member that does not have a sliding force that can completely seal the inside and the outside of the front reducer by itself with respect to the rotating shaft or the relative rotating member of the front reducer. The lubricant absorbing member may be disposed between the rotation shaft of the reduction gear and the relative rotation member, and at the outside of the front reduction gear (that is, the rear reduction gear).

  In other words, if it is desired to prevent the leakage of the lubricant in the subsequent reduction gear, a lubricant absorbing member is arranged on the outer side of the downstream reduction device with respect to the arranged seal member, and the leakage of the lubricant in the previous reduction gear is prevented. If you want to prevent, place a lubricant absorbing member on the outside of the front reducer, and if you want to prevent lubricant leakage from both sides of the front and rear reducers, both sides of the front and rear A lubricant absorbing member may be disposed.

  Thus, the “seal structure that partitions the inside and outside of the speed reducer” does not necessarily mean only the “seal structure that partitions the entire inside of the device from the complete external space”, but a specific inside of the device. The present invention can also be applied as a seal structure that partitions the inside and the outside of the individual reducer. As such an example, in addition to the seal between the plurality of individual reduction gears described above, for example, a seal between the individual reduction gear and the motor case, a seal between the individual reduction gear and the brake box, and the like can be considered. .

  In addition, the rotating shaft in this invention does not necessarily need to be a high-speed shaft whose rotational speed is faster than the output shaft of the speed reduction mechanism.

  The lubricant absorbing member does not necessarily have to be arranged between the rotation shaft of the speed reducer and the relative rotating member, and it is not always necessary to have a plurality of lubricant absorbing members. The rotating shaft and the relative rotating member or the integral member of the relative rotating member may not be alternately arranged along the axial direction.

  In the above embodiment, grease is used as the lubricant, but not only grease but also oil may be used.

  As the first seal member, even if it has an urging member, it has a sealing function to the extent that it does not have a sliding force that can be completely sealed, or is stationary (no overload) The seal function may be weakened so that it does not leak during operation.

  Moreover, the 1st, 2nd seal member is arrange | positioned on both sides which pinched | interposed the deceleration mechanism of the rotating shaft, and the sliding elastic force of the 1st seal member arrange | positioned at the one side of the rotating shaft can seal completely. Regardless of whether or not it has sliding force, it is weaker than the sliding force of the second seal member arranged on the other side, and is outside the speed reducer than the first seal member. Alternatively, the lubricant absorbing member may be arranged.

  In the above-described embodiment, the lubricant absorbing member is disposed only on the first seal member side (the outer side of the speed reducer than the first seal member), but the second seal (in addition to the first seal member side). It is good also as a structure by which the lubricant absorption member is arrange | positioned also at the member side at the exterior side of the reduction gear.

  In addition, among the components and elements described in the embodiment, even if not specifically described, the dimensions, materials, shapes, and other relative arrangements of the components are not particularly specified, unless otherwise specified. The scope of the present invention is not intended to be limited to that.

DESCRIPTION OF SYMBOLS 100 ... Input shaft 107 ... 1st seal member 120 ... Flange body (relative rotation member)
121, 123 ... Lubricant absorbing member 131 ... Seal structure 135 ... Reduction mechanism G1 ... Reduction gear X ... Sliding tension force

Claims (10)

A rotation shaft of the speed reduction mechanism, and a relative rotation member that rotates relative to the rotation shaft, and the inside and outside of the speed reducer via a seal member that is incorporated between the rotation shaft and the relative rotation member A reduction gear seal structure for partitioning,
First and second seal members are arranged on both sides of the rotating shaft with the speed reduction mechanism interposed therebetween,
The sliding force of the first seal member is weaker than the sliding force of the second seal member, and
A lubricant absorbing member is disposed on the outside of the speed reducer with respect to the first seal member. A seal structure for a speed reducer. A rotation shaft of the speed reduction mechanism, and a relative rotation member that rotates relative to the rotation shaft, and the inside and outside of the speed reducer via a seal member that is incorporated between the rotation shaft and the relative rotation member A reduction gear seal structure for partitioning,
The seal member does not have a sliding force that can completely seal the inside and the outside of the speed reducer by itself with respect to the rotating shaft or the relative rotating member, and
A seal structure for a speed reducer, wherein a lubricant absorbing member is disposed outside the speed reducer with respect to the seal member. In claim 1 or 2,
The speed reducer, wherein the seal member or the first seal member does not have a biasing member that biases a part of the seal member or the first seal member against the rotating shaft or the relative rotating member. Seal structure. In any one of Claims 1-3,
The value of (the sliding tension force) / (the inner diameter of the seal member or the first seal member) of the seal member or the first seal member is less than 0.2 N / mm. Seal structure. In any one of Claims 1-4,
The bearing structure that supports the rotating shaft is a seal bearing, and the seal member or the first seal member is a seal piece disposed in the seal bearing. A reduction shaft that includes a rotation shaft of a reduction mechanism and a relative rotation member that rotates relative to the rotation shaft, and is configured between the rotation shaft and the relative rotation member, and partitions the inside and the outside of the reduction device. A seal structure,
A narrow portion is formed between the rotating shaft and the relative rotating member, and
A seal structure for a speed reducer, wherein a lubricant absorbing member is disposed outside the speed reducer with respect to the narrow portion. In any one of Claims 1-6,
The rotary shaft is a high-speed shaft whose rotational speed is higher than that of the output shaft of the speed reduction mechanism. In any one of Claims 1-7,
The speed reducer has a labyrinth structure on the inner side of the speed reducer than the lubricant absorbing member. In any one of Claims 1-8,
The rotating shaft includes a hollow portion along the axial direction at a radially central portion,
A cylindrical member is disposed on the radially inner side of the hollow portion in a non-contact manner with the rotating shaft, and the lubricant absorbing member is disposed between the cylindrical member and the rotating shaft. Reducer seal structure. In any one of Claims 1-9,
The speed reducer includes two or more lubricant absorbing members,
Among these, one lubricant absorbing member has a gap between the rotating shaft and the other lubricant absorbing member has a gap between the relative rotating member or a member integral with the relative rotating member. A reduction gear seal structure, characterized by being arranged along the axial direction.

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