JP2006038019A - Reduction gear with air vent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reduction gear with an air vent capable of preventing a lubricant which is filled inside the casing of the reduction gear from leaking outside through an air vent, without raising the internal pressure of reduction gear beyond the tolerable pressure of a seal component. <P>SOLUTION: The reduction gear with an air vent comprises a casing 20 which is provided with a gear mechanism for reducing speed and transmitting the torque of an input part to an output part, and forms an internal volume part in which a lubricant is sealed up, and another spatial volume 10 which is provided to communicate with the internal volume. That another spatial volume is so arranged as to be positioned on the vertical upper V side of the upper surface of lubricant inside the internal volume with an air vent 12 provided to a part of that spatial volume. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a speed reducer with an air vent hole that prevents a lubricant or the like filled in a casing of the speed reducer from leaking from the air vent hole to the outside.

  As a conventional speed reducer with an air vent hole, for example, the following Patent Document 1 is a cylindrical body having a void portion communicating with an air vent hole on the inner side of an oil plug and having a void portion communicating with the void portion on the outer periphery. Disclosed is a speed reducer in which a blowout prevention body is inserted into a void portion. A gear is arranged inside the casing of the reduction gear, but in order to reduce the frictional resistance of the sliding portion, the casing is filled with a lubricant (grease or the like).

  In recent years, the operating speed has been increased to improve the productivity of manufacturing equipment, and the downtime has become shorter, so the speed of the reducer used in the manufacturing equipment has increased and the stop time has also become shorter. Yes. For this reason, the temperature rise inside the casing of the speed reducer increases, and as a result, the pressure inside the casing increases, and in some cases, the tolerance of the seal component disposed between the fixed part (casing) and the rotating part (shaft) is allowed. There is a risk that a phenomenon in which the pressure resistance is exceeded and the lubricant leaks from the inside of the casing to the outside may occur.

However, in such a conventional speed reducer with an air vent hole, a cylindrical portion having a void portion communicating with the air void hole on the outer periphery and having a void portion communicating with the void portion on the outer periphery. The body blowout prevention body is inserted into the void portion to prevent the lubricant from blowing out from the air vent hole, and only the air is blown out to reduce the pressure inside the casing. However, it is necessary to form an air vent at an upper position sufficiently away. When the lubricant of about 70 to 90% of the internal volume is filled like a reduction gear, there is a possibility that the lubricant is blown out with such an air vent structure.
JP 200121022 A

  In view of the above-described problems of the prior art, the present invention does not leak the lubricant filled in the casing of the speed reducer from the air vent hole to the outside without increasing the internal pressure of the speed reducer beyond the allowable pressure resistance of the seal component. An object of the present invention is to provide a reduction gear with an air vent hole.

  In order to achieve the above object, the speed reducer with an air vent according to the present invention is provided with a gear mechanism for decelerating and transmitting the torque of the input part to the output part and forms an internal volume part in which the lubricant is enclosed. And another space volume portion provided so as to communicate with the internal volume portion, and the other space volume portion is positioned above the upper surface of the lubricant in the internal volume portion in the vertical direction. It arrange | positions like this, The air vent hole is provided in a part of said another space volume part, It is characterized by the above-mentioned.

  According to this speed reducer with an air vent hole, since another space volume portion is interposed vertically between the internal volume portion in which the lubricant in the casing is sealed and the air vent hole, the air vent It is possible to prevent the lubricant in the internal volume portion from leaking out of the hole.

  In the speed reducer with the air vent hole, it is preferable that the volume of the another space volume part is 10% or more of the internal volume part. Thereby, even if the temperature inside the casing of a reduction gear rises and the internal pressure of a casing becomes high in connection with it, it can prevent reliably that a lubricant leaks from an air vent hole.

  In addition, since at least a part of the other space volume portion is made of a transparent member, the state of the lubricant in the other space volume portion can be easily observed, so it is possible to determine the replacement time of the lubricant, and to perform maintenance. Improves.

  In addition, since a filter is provided in the air vent hole, foreign matter can be prevented from entering the reducer from the air vent hole.

  Moreover, it is preferable that the pipe which connects the said internal volume part and said another space volume part is bend | folded in the rotating shaft direction within the said internal volume part. When the rotating member provided in the internal volume of the reducer rotates, the internal lubricant tries to move in the radial direction due to the centrifugal force, but moves in the radial direction by the pipe bent in the direction of the rotation axis. This makes it difficult for the lubricant to move to another space volume, and the air expanded by the temperature rise can be efficiently moved to another space volume.

  Note that the allowable pressure resistance of the seal part needs to be increased in order to prevent leakage from the seal part arranged between the casing and the output part or the input part. Since the leakage of the lubricant from the air vent hole can be prevented without increasing the pressure resistance, it is not necessary to increase the allowable pressure resistance of the seal component.

  According to the speed reducer with an air vent hole of the present invention, the lubricant filled in the casing of the speed reducer can be prevented from leaking outside from the air vent hole without increasing the internal pressure of the speed reducer to the allowable pressure resistance of the seal part. .

  Hereinafter, first and second embodiments for carrying out the present invention will be described with reference to the drawings.

  <First Embodiment>

  FIG. 1 is a top view of the inside of a speed reducer with an air vent hole according to the first embodiment as viewed from above. FIG. 2 is a front view of the speed reducer with an air vent hole of FIG. 1 as seen from the direction II of FIG.

  As shown in FIGS. 1 and 2, the speed reducer 1 with the air vent hole according to the first embodiment includes a speed reducer main body 2 having an eccentric oscillation type reduction gear mechanism, and a bolt or the like on the speed reducer main body 2. An intermediate flange 3 attached with a fixing member 3a and a motor flange 4 attached to the intermediate flange 3 with a fixing member 4a such as a bolt are provided. The motor 5 is fastened to the motor flange 4, and an input gear 6 integrated with a rotary shaft 6 a that is an input unit is fixed to the motor 5. An input side oil seal 7 is provided between the intermediate flange 3 and the input gear 6.

  The speed reducer main body 2 has a casing 20, an internal gear 25 composed of a plurality of pins (internal teeth), and external teeth having a different number of teeth from the internal gear 25 at a predetermined pitch corresponding to the internal gear 25, for example. An external gear 24 that meshes with the internal gear 25, a plurality of crankshafts 22 that support the external gear 24 so as to be able to revolve eccentrically with respect to the central axis of the internal gear 25 via bearings, The spur gear 23 that meshes with the input gear 6 at the shaft end portion of 22 and the casing 20 are rotatably coupled to the casing 20 via rolling bearings 29 and 30, and the output that supports both ends of the crankshaft 22 rotatably via the bearings. The shaft 21 and the output-side oil seal 27 disposed between the casing 20 and the output shaft 21 are provided.

  The casing 20 is fixed to another base or member, for example, with the mounting hole 20a, so that at least one of the plurality of crankshafts 22 is connected to the motor 5 via the spur gear 23 and the input gear 6 at the end of the shaft. The external gear 24 meshes with the internal gear 25 having, for example, one tooth number larger than the number of teeth of the external gear 24 while revolving. The external gear 24 rotates in accordance with the difference in the number of teeth (1) per revolution, whereby the output shaft 21 can rotate corresponding to the rotation of the external gear 24 and take out the deceleration output.

  In the speed reducer main body 2, one internal volume portion is formed by the casing 20, the intermediate flange 3, the output shaft 21, and the two input / output side oil seals 7 and 27, and the above reduction gear mechanism is configured. The liquid lubricant 8 is filled in, for example, about 70 to 90% of the space in the internal volume portion.

  The intermediate flange 3 is provided with a lubricant supply port 9 a, and a pipe 9 screwed and fixed to the supply port 9 a extends from the supply port 9 a and is connected to the cylindrical body portion 11. Another space volume portion 10 is formed in the cylindrical body portion 11, and the other space volume portion 10 communicates with the internal volume portion in the speed reducer main body 2 via the tube 9. The volume of the other space volume portion 10 is 10% or more of the internal volume portion in the speed reducer main body 2. A pipe 9b is screwed and fixed to a pipe 9 fixed to the inlet 9a. The pipe 9b is bent in the direction c of the rotating shaft 6a within the internal volume, and the tip of the pipe 9b is connected to the direction c. It is almost parallel.

  The cylindrical body portion 11 is formed in a cylindrical shape from a transparent member such as glass or acrylic resin, and an air vent hole 12 is formed in the top flat surface 11a of the cylindrical body portion 11. A filter 13 is fitted in the air vent hole 12. ing.

  As shown in FIG. 2, the pipe 9 connected to the supply port 9a extends slightly in the horizontal direction and then extends upward V in the vertical direction to connect to the bottom plane 11b of the cylindrical body portion 11. The cylindrical body portion 11 has its central axis. Are arranged so as to substantially coincide with the vertical direction. The vertical position (level) of the cylindrical part 11 is higher than the liquid level 8a indicated by the broken line in FIG. 2 of the lubricant whose bottom plane 11b is filled in the internal volume part in the speed reducer main body 2. It is decided so.

  In addition, the internal volume part in the speed reducer main body 2 is filled with about 90% of the lubricant at the maximum. The level becomes the liquid level 8a indicated by the broken line in FIG. Even in this case, there is no problem because it is lower than the bottom plane 11b.

  As described above, according to the speed reducer 1 with the air vent hole shown in FIGS. 1 and 2, the air vent hole 12 is separately provided between the internal volume portion formed from the casing 20, the intermediate flange 3, and the like and filled with the lubricant. Since the space volume portion 10 of the internal volume portion is interposed so as to be positioned on the V side above the highest liquid level 8a of the internal volume portion, the lubricant 8 in the internal volume portion is prevented from leaking from the air vent hole 12 to the outside. it can. In this case, when the volume of the separate space volume portion 10 is 10% or more of the internal volume portion, the temperature inside the speed reducer body 2 rises, and the internal pressure of the speed reducer body 2 increases accordingly. In addition, the lubricant can be reliably prevented from leaking from the air vent hole 12.

  That is, if the speed reducer 1 with the air vent hole is continuously operated, the internal temperature rises, and when the air in the internal volume portion expands, the lubricant moves to another space volume portion 10 through the tube 9, so that the internal pressure is reduced. The rise is suppressed and the lubricant does not leak out as it blows out from the air vent hole 12. In the case of a conventional speed reducer that does not have a separate space volume, the temperature inside the casing rises due to heat generation during operation, and the air and lubricant expand (usually, the expansion of air is dominant). The higher the temperature, the higher the internal pressure and the more likely the problem of blowing out the lubricant. For example, when the lubricant is filled in a space of about 70 to 90% of the internal volume, the conventional air venting is performed. In the structure, when the air is blown out, the lubricant is also blown out together. However, in the first embodiment, the lubricant is received by another space volume 10 and the increase in the internal pressure is suppressed. Therefore, no lubricant is blown out. For this reason, it is also possible to rotate at high speed.

  Further, the cylindrical body portion 11 forming another space volume portion 10 is made of a transparent member, and the state of the lubricant moved into the other space volume portion 10 during operation can be easily observed. The replacement time can be determined, and maintenance is improved. Further, since the filter 13 is provided in the air vent hole 12, it is possible to prevent foreign matter from entering the inside of the speed reducer main body 2 through the pipe 9 from the air vent hole 12.

  Also, the internal lubricant tends to move in the radial direction due to the centrifugal force of the rotating shaft 6a rotating during the operation of the speed reducer, but the pipe 9b connected to the tube 9 is bent in the direction c of the rotating shaft 6a. The lubricant that moves in the radial direction is unlikely to move to another space volume 10, and the air expanded by the temperature rise can be efficiently moved to another space volume 10.

  In the first embodiment, since the lubricant can be prevented from leaking from the air vent hole 12 as described above, it is necessary to particularly increase the allowable pressure resistance of the input side oil seal 7 and the output side oil seal 27. Absent.

  <Second Embodiment>

  The cylindrical body part 11 forming another space volume part 10 in FIGS. 1 and 2 may be disposed at another position as long as the bottom plane 11b is higher than the highest liquid level 8a. That is, in the speed reducer with an air vent hole according to the second embodiment, as shown in FIG. 3, the lubricant inlet 9a is provided near the top of the intermediate flange 3 in the vertical direction, and the pipe 9c extends upward from the inlet 9a. And is connected to the bottom flat surface 11 b of the cylindrical body 11.

  According to the speed reducer with the air vent hole in FIG. 3, the bottom plane 11b of the cylindrical body 11 is always higher than the maximum liquid level 8a in the space volume in the speed reducer body than in the case of FIG. For this reason, the lubricant does not exist in the supply port 9a and the pipe 9c, and the amount of the lubricant that comes out from the inside of the speed reducer main body to another space volume 10 becomes smaller than that in the case of FIG. This is because the expansion of air is larger than the expansion of the lubricant, and the amount of air expanded from the air layer (or in the vicinity of the air layer) in the space volume in the reducer body is another space volume 10. This is because the amount of lubricant pushed out when the air expands is small.

  Next, the present invention will be described more specifically with reference to examples. For the speed reducer with the air vent hole similar to FIG. 3, the temperature and internal pressure of the casing rising due to heat generation during operation were measured, and the state of the lubricant visible in another space volume was observed.

  FIG. 4A is a diagram showing a time change of the casing temperature that rises due to heat generation during operation of the speed reducer with an air vent of this embodiment, and FIG. 4B is a diagram showing a time change of the internal pressure.

The operating conditions of the speed reducer with an air vent hole of this example were as follows as shown in FIG.
・ 0 to 2.5 hours: operation at 60% of the actual operating conditions ・ 2.5 to 4.5 hours: operation at the actual operating conditions of 80% ・ 4.5 to 7 hours: at the actual operating conditions Stop after 7 hours of operation

  When the speed reducer with the air vent hole of the present embodiment is started at a casing temperature of 20 ° C. with no lubricant in another space volume and continued to operate under the above-mentioned conditions, the casing temperature gradually increases. However, up to 4.5 hours, the internal pressure does not increase from a certain value because of the air vent hole, but it does not completely escape and maintains a substantially constant value. After 4.5 hours, air escaped and the internal pressure decreased. During this operation, the lubricant entered another space volume, but it was about half the volume. The lubricant was not blown out or leaked from the air vent hole in another space volume. When the operation was stopped, the temperature gradually decreased, and the lubricant almost returned to the speed reducer main body from another space volume.

  As described above, the first and second embodiments and examples for carrying out the present invention have been described. However, the present invention is not limited to these and is within the scope of the technical idea of the present invention. Various modifications are possible. For example, in FIG. 2, the air vent hole 12 may be provided on the circumferential side surface 11 c (FIG. 2) of the cylindrical body portion 11 as long as it is vertically above the bottom plane 11 b.

  Moreover, although the speed reducer with an air vent hole of FIGS. 1-3 is used with the attitude | position as shown in figure with respect to the perpendicular direction, this invention is not limited to this, Another attitude | position (with respect to the speed reducer) In such a case, the cylindrical body portion 11 may be arranged so that the bottom plane 11b is at a level higher than the maximum liquid level 8a according to the posture. . The speed reducer according to the present invention is useful for applications in which the rotational axis direction of the speed reducer, such as a traveling shaft portion of a traveling robot, a turning shaft portion of an articulated robot, and a table axial movement device of a machine tool, is unchanged. For example, the present invention can be applied to relatively high-speed rotation in which the input rotation speed from the motor to the reduction gear is about 2500 rpm and the output rotation speed of the reduction gear is about 500 ppm.

It is the top view which looked at the inside of the reduction gear with an air vent hole by 1st Embodiment from upper direction. It is the front view seen from the direction II of FIG. 1 by notching a part of the speed reducer with the air vent hole of FIG. It is the same front view as FIG. 2 which shows the reduction gear with an air vent hole by 2nd Embodiment. FIG. 4A is a diagram showing a time change of the casing temperature that rises due to heat generation during operation of the speed reducer with the air vent hole of the embodiment, and FIG. 4B is a diagram showing a time change of the internal pressure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reduction gear with air vent 2 Reduction gear main body 3 Intermediate flange 5 Motor 6 Input gear 7 Input side oil seal 8 Lubricant 8a Liquid level, highest liquid level 9, 9c Pipe 9a Supply port 10 Another space volume 11 Cylinder Body 11a Top plane 11b Bottom plane 11c Circumferential side surface 12 Air vent hole 13 Filter 20 Casing 21 Output shaft 22 Crank shaft 23 Spur gear 24 External gear 25 Internal gear 27 Output oil seal V Vertically upward

Claims (5)

A casing that is provided with a gear mechanism for decelerating and transmitting the torque of the input part to the output part and forms an internal volume part in which a lubricant is enclosed;
Another spatial volume provided to communicate with the internal volume, and
The another space volume part is disposed so as to be positioned vertically above the upper surface of the lubricant in the internal volume part, and an air vent hole is provided in a part of the other space volume part. Reducer with air vent hole.   2. The speed reducer with an air vent hole according to claim 1, wherein the volume of the another space volume part is 10% or more of the internal volume part.   3. The speed reducer with an air vent hole according to claim 1, wherein at least a part of the another space volume portion is made of a transparent member.   The speed reducer with an air vent hole according to claim 1, 2 or 3, wherein a filter is provided in the air vent hole. 5. The deceleration with an air vent hole according to claim 1, wherein a pipe that connects the internal volume portion and the another space volume portion is bent in a rotation axis direction within the internal volume portion. Machine.

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