JP2011148077A - Joint part structure of industrial equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively and comparatively inexpensively prevent a liquid component of a grease or a lubricant from leaking to the outside while hardly causing a loss in a driving torque. <P>SOLUTION: In a circular recess 10a of a first frame 10, a speed reducer 12 containing the grease, and reducing the rotation of a servomotor 13 to transmit it to a rotation body 14 is provided, and an outer ring 15a of a bearing 15 is fixed. The rotation body 14 secured on a second frame 11 is connected to an inner ring 15b of the bearing 15 so as to be rotatably supported. The outer circumference of the circular recess 10a of the first frame 10 is integrally provided with a first cylindrical wall 16, and the inner circumferential surface of the first cylindrical wall 16 is provided with an annular first felt member 17 all over the circumference. The outer circumferential side, from the first cylindrical wall 16, of the outer surface of the second frame 11 is integrally provided with a second cylindrical wall 18, and an annular second felt member 19 is provided all over the circumference of the inner circumferential side of the second cylindrical wall 18. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an industrial device in which a first frame and a second frame that are arranged to face each other in the direction of the rotational axis are coupled so as to be relatively rotatable via a mechanism having grease or a lubricant. It is related with the joint part structure.

  As a structure of an articulated part in an industrial equipment, for example, a small assembly robot having a small portable weight, a first frame and a second frame are connected rotatably by a bearing and, for example, a motor provided in the first frame There is a type provided with a speed reducer that transmits the rotational force to the second frame. In this case, the reducer is lubricated with grease, but this grease may leak out from the joint. Therefore, in general, a rubber oil seal is provided in the vicinity of the bearing in order to prevent grease from leaking outside the joint (see, for example, Patent Documents 1 and 2).

  The rubber oil seal is composed of a metal ring and a rubber lip provided on the inner peripheral portion thereof. For example, the outer peripheral metal ring is fixed to the first frame side, and the inner peripheral lip is set to the second frame side. It comes in pressure contact with the sealing surface of the outer peripheral wall. Thereby, with the relative rotation of the second frame, the lip comes into contact with the sealing surface to perform sealing while sliding relatively. Note that an O-ring for improving the sealing performance is provided on the overlapping surface of the components, and grease is applied to the outer surface of the O-ring.

JP 2007-187234 A JP 2007-182756 A

  By the way, this type of robot may be used in a clean environment where it is desired to suppress the leakage of grease at the joint. In such a case, it is desired to further improve the effect of preventing the leakage of grease. Is done. In order to meet such a demand, a configuration in which a second rubber oil seal similar to the rubber oil seal is provided on the outer peripheral side of the bearing at the joint portion, that is, a rubber oil seal is provided twice. It is done.

  However, in the configuration in which the rubber oil seal is provided twice, the following problems occur. That is, the rubber oil seal has a structure in which the lip moves relative to the seal surface of the second frame while being elastically pressed, and the sliding resistance at that time increases, resulting in a torque loss. In addition, in order to obtain high sealing performance, it is necessary to increase the dimensional accuracy of the rubber oil seal itself and the parts of the assembly portion, and also to provide a high accuracy of the assembly, which increases the cost as a whole.

  In the case of a rubber oil seal, the joint portion is sealed at the seal portion. For example, the pressure at the inner portion of the seal rises due to the temperature rise of the joint portion, and the pressure difference with the outside (atmosphere) is increased. May occur. For this reason, it is considered that the pressure is released at a stretch in the rubber oil seal with the weakest seal strength, and the pressure is released all at once, and the grease blows out and scatters, contaminating the surroundings. There is a risk of it.

  The present invention has been made in view of the above circumstances, and the object thereof is to effectively prevent leakage of liquid components of grease or lubricant to the outside without causing loss of driving torque and being relatively inexpensive. An object of the present invention is to provide a joint structure for industrial equipment that can be prevented.

  In order to achieve the above-mentioned object, the joint part structure of an industrial device according to claim 1 of the present invention has a first frame and a second frame arranged opposite to each other in the rotational axis direction, and has grease or a lubricant. In the structure in which the first frame is connected so as to be relatively rotatable via a mechanism portion, the first frame is located on the outer peripheral side of the mechanism portion and has a cylindrical shape centered on the rotation axis. A first cylindrical wall is provided so as to protrude to the second frame side, and an inner peripheral side portion of the first cylindrical wall of the bottom surface of the first frame connected to the first cylindrical wall is provided with the mechanism portion. An annular first fibrous sucking member for absorbing the grease or the liquid component of the lubricant that leaks out from the outer surface of the second frame facing the first frame is provided over the entire circumference. The portion located on the outer peripheral side of the mechanism portion has the mechanism From leaking to absorb liquid component of the grease or lubricant, the second fibrous blotter annular member having characterized in that provided over the entire circumference.

  Here, the grease provided for lubrication of the mechanism part is composed of a base oil and an additive, and usually has a semi-solid shape with viscosity, but with temperature change and aging change. Then, the base oil and the additive are separated, and the base oil that is a liquid component flows out slightly.

  According to the above configuration, a small part of the liquid component of the grease or the lubricant contained in the mechanism unit is transmitted on the surface of the first frame or the second frame by an action such as centrifugal force or gravity. Leak from the mechanical part to the outer periphery. Among them, the liquid component transmitted through the surface of the first frame is absorbed and captured by the annular first fibrous suction member provided on the inner peripheral side portion of the bottom surface connected to the first cylindrical wall. Further, the liquid component transmitted through the surface of the second frame is absorbed and captured by the annular second fibrous suction member provided on the outer surface of the second frame. In this case, the liquid component in the form of a film can be easily absorbed by the first fibrous suction member and the second fibrous suction member.

  Therefore, it is possible to effectively prevent the grease component or the liquid component of the lubricant in the mechanism portion from being reliably captured by the first fibrous suction member and the second fibrous suction member and leaking to the outside beyond that. The “fibrous blotting member” in the present invention refers to a member that can absorb liquid, and more specifically, there are felt, nonwoven fabric, paper, cotton, and the like made of a fiber material. Also included are porous members such as plastic sponges.

  By the way, according to the research by the present inventors, in the case of a small industrial robot having a small portable weight (for example, a portable weight of 20 kg or less) as an industrial device, a standard maintenance period (for example, five years) in one joint portion. The amount of liquid (base oil) that leaks to (1) is at most 1 to 2 ml, and can be sufficiently captured and absorbed by the fibrous suction member. In this way, for example, from the amount of leakage of liquid that is experimentally or theoretically determined, the volume of the fibrous suction member (dimensions such as thickness and width) sufficient to absorb the liquid that may leak during a standard maintenance period, for example. ) Is calculated in reverse, and an amount of fibrous suction member corresponding to that is provided.

  At this time, since the first fibrous suction member can be provided in a non-contact manner with respect to the member on the second frame side, sliding resistance does not occur. In addition, the second fibrous suction member can be provided in a non-contact manner with respect to the member on the first frame side, so that sliding resistance does not occur. Even if the second fibrous sucking member comes into contact (slide) with the tip of the first cylindrical wall at the beginning of use due to circumstances such as dimensional accuracy, the sliding portion of the second fibrous sucking member is Since it easily wears and forms a gap, it eventually becomes a non-contact state at an early stage. Therefore, unlike the case with sliding such as an oil seal, it is possible to suppress the loss of driving torque due to sliding resistance.

  The first fibrous sucking member and the second fibrous sucking member that are both annular are not expensive in material as compared with the oil seal, so that the member itself can be manufactured at a relatively low cost. The first fibrous sucking member and the second fibrous sucking member are respectively provided in an annular shape, that is, a flat plate shape, with respect to a flat plate portion such as a bottom surface of the first frame and an outer surface of the second frame. Therefore, as compared with the case where the fibrous suction member is attached to the curved surface, the mounting operation is facilitated. In this case, there is no possibility that a gap is formed over the entire circumference by using the fibrous suction member configured in an annular shape. As a result, the overall cost can be reduced. Furthermore, unlike the oil seal, there is no sealing between the inner peripheral side and the outer peripheral side of the joint part, so there is no pressure difference between the inside and outside of the joint part, and the leaked liquid is blown out and scattered. It is possible to prevent such troubles as to occur.

  In the present invention, the second frame has a cylindrical shape centered on the rotation axis, and a second cylindrical wall that protrudes toward the first frame with a gap on the outer peripheral side of the first cylindrical wall. And the annular second fibrous suction member can be provided over the entire circumference on the inner peripheral side portion of the second cylindrical wall of the bottom surface continuous with the second cylindrical wall. Invention).

  According to this, the liquid component leaking along the surface of the second frame is absorbed by the second fibrous sucking member provided on the inner peripheral side of the second cylindrical wall, and outside the second cylindrical wall. It is possible to prevent leakage. Positioning and attachment can be easily performed by causing the outer peripheral edge of the second fibrous suction member to be along the proximal end on the inner peripheral side of the second cylindrical wall. Further, since the first fibrous suction member and the second fibrous suction member are hidden by the first cylindrical wall and the second cylindrical wall and cannot be seen from the outside, the fibrous suction member that sucks a liquid such as oil. There is no such thing as seeing and getting worse.

  In addition, since there is no fibrous sucking member or the like between the inner peripheral surface of the second cylindrical wall and the outer peripheral surface of the first cylindrical wall, the second cylindrical wall is made the outer peripheral surface of the first cylindrical wall accordingly. It can be provided close, that is, with a small diameter. As a result, the size in the diameter direction of the entire joint portion can be saved without being increased in size.

  In the present invention, the first fibrous sucking member and the second fibrous sucking member can be provided so as to partially overlap each other when viewed in the rotational axis direction (invention of claim 3). According to this, the first fibrous sucking member and the second fibrous sucking member are arranged to face each other in the axial direction through a gap that extends and expands in the circumferential direction at the overlapping portion.

  At this time, even if the liquid leaking from the mechanism portion tries to exit to the outer peripheral side through the gap between the first fibrous suction member and the second fibrous suction member, the first fibrous suction member In addition, the surface of the second fibrous sucking member is somewhat fuzzy, and in industrial equipment such as robots, the joints themselves often move randomly in the vertical and horizontal directions. Therefore, the liquid that has entered the gap between the first fibrous sucking member and the second fibrous sucking member is easily applied to the fluffy fiber on the surface of either the first fibrous sucking member or the second fibrous sucking member. And is surely captured by one of the fibrous suction members by capillary action. As a result, it is possible to more effectively prevent the liquid from leaking out.

  By the way, when the first fibrous sucking member and the second fibrous sucking member are arranged facing each other with a gap, it is desirable to make the gap as small as possible from the viewpoint of reducing the overall size. . However, as described above, the surfaces of the first fibrous sucking member and the second fibrous sucking member are somewhat fluffy, so if the gap between them is small, the first fibrous sucking member When the sucking member and the second fibrous sucking member are relatively rotated, the fluffy fibers on the surface are tangled and torn apart, and dust consisting of fiber waste may be generated (see FIG. 6). .

  Therefore, in the present invention, a portion where the first fibrous suction member and the second fibrous suction member face each other with a gap between the first fibrous suction member and the second fibrous suction member. A thin plate-like partition member for separating the two can be arranged (invention of claim 4). According to this, the fiber of the surface of the 1st fibrous suction member and the fiber of the surface of the 2nd fibrous suction member are separated by the partition member, and it can prevent it from contacting directly. As a result, the fibers can be prevented from being entangled as a result of relative rotation, and as a result, the generation of dust.

  At this time, it is desirable that the thin partition member has a smooth surface so that it can slide with a small frictional force even when fibers on the surface of the fibrous suction member come into contact with each other and slide. As this partition member, for example, a plastic thin plate such as PET or acrylic having a thickness dimension of about 0.1 to 0.5 mm can be used, or a thin metal plate can be adopted.

  The partition member may be formed in an annular shape so as to cover the entire facing portion of the first fibrous suction member and the second fibrous suction member. The inner or outer peripheral edge of the annular partition member may be fixed (fitted) to any one of the frames, and a certain amount of play is ensured after securing the retaining state. May be fitted. Furthermore, you may make it affix on either fibrous suction member with an adhesive agent. However, the partition member may be disposed in a state in which a gap through which the liquid component passes is secured so as not to interfere with the absorption of the liquid component of the grease or the lubricant by the first fibrous suction member and the second fibrous suction member. is important.

  Alternatively, in the present invention, one of the first fibrous suction member and the second fibrous suction member can have the same outer diameter and the other inner diameter (the invention of claim 5). ). According to this, material removal of the first fibrous suction member and the second fibrous suction member can be performed efficiently, and the cost of the fibrous suction member can be reduced accordingly. In addition, the outer peripheral end of one of the first fibrous sucking member and the second fibrous sucking member and the other inner peripheral end of the first fibrous sucking member can be disposed close to each other with a gap therebetween, so that the above-mentioned claim 3 Due to the same action as above, it can be expected that the liquid that has entered the gap is reliably captured by either the first fibrous suction member or the second fibrous suction member.

1 shows a first embodiment of the present invention, and is a longitudinal front view schematically showing a configuration of a joint portion connecting a lower arm and a first upper arm. FIG. Enlarged longitudinal sectional view of part A in FIG. The perspective view which shows the external appearance structure of a robot main body FIG. 1 equivalent view showing a second embodiment of the present invention. The expanded longitudinal cross-sectional view of the principal part of a joint part which shows the 3rd Example of this invention The figure for demonstrating a mode that dust generate | occur | produces when the 1st felt member and the 2nd felt member are facing each other with a gap.

(1) First Embodiment Hereinafter, a first embodiment in which the present invention is applied to a robot as an industrial device will be described with reference to FIGS. Here, a specific example is a small industrial robot having a load capacity of 20 kg or less (for example, 10 kg), for example, a 6-axis vertical articulated robot. FIG. 3 schematically shows the appearance of the robot body 1 (viewed from the front and slightly from the upper right). The robot body 1 is configured to include a six-axis arm on a base 2, and these arms are connected so as to be sequentially turnable through joint portions as follows.

  That is, a shoulder portion 3 is connected to the base 2 so as to be pivotable in a horizontal direction around a rotation axis J1 extending in the vertical direction, and a lower arm 4 extending upward in the figure is connected to the shoulder portion 3. These are coupled so as to be pivotable in the vertical direction about a rotation axis J2 extending in the horizontal direction. A first upper arm 5 is connected to the tip of the lower arm 4 so as to be pivotable in the vertical direction about a rotation axis J3 extending in the horizontal direction. The second upper arm 6 is coupled so as to be coaxially rotatable about the rotation axis J4. A wrist 7 is connected to the distal end of the second upper arm 6 so as to be pivotable in the vertical direction about a pivot axis J5, and a flange 8 is centered on the pivot axis J6 at the distal end of the wrist 7. To be coaxially rotatable. A tool such as a hand (not shown) is attached to the flange 8.

  FIG. 1 shows a joint portion 9 between the shoulder portion 3 and the lower arm 4 as a representative of the joint portion provided in the robot body 1, and the joint portion 9 is a joint portion structure according to the present embodiment. It has. In the joint portion 9, the first frame 10 constituting the outer shell of the shoulder portion 3 and the second frame 11 constituting the outer shell of the lower arm 4 extend in the direction of the rotation axis J2 extending in the left-right direction in the drawing. These are connected so as to be rotatable around a rotation axis J2 via a speed reducer 12 as a mechanism portion. The speed reducer 12 decelerates and transmits the rotation of the servo motor 13 provided in the shoulder 3 (first frame 10) to the second frame 11 (lower arm 4).

  A circular recess 10a is provided at the front end of the first frame 10, that is, on the second frame 11 side, that is, on the right side in the drawing, and a circular through hole 10b is formed at the center of the bottom of the circular recess 10a. Is formed. A servo motor 13 is disposed in the first frame 10 so as to face right in the drawing, and its shaft 13a protrudes rightward, that is, into the circular recess 10a through the through hole 10b. At this time, the center of the shaft 13a (and the center of the circular recess 10a) coincides with the rotation axis J2.

  On the other hand, the surface of the base end portion of the second frame 11 facing the first frame 10 (the surface facing the left side in the figure) is a circular convex portion 11a that is slightly convex toward the first frame 10 side. Is provided. The outer diameter of the circular convex portion 11a is slightly smaller than the inner diameter of the circular concave portion 10a. A rotating body 14 having a cylindrical block shape (ring shape) is connected (fixed) to the tip surface of the circular convex portion 11a. At this time, the center of the rotating body 14 and the center of the circular convex portion 11a also coincide with the rotation axis J2.

  At this time, a bearing 15 made of a cross roller bearing is provided so as to be fitted to the inner peripheral surface portion of the circular recess 10 a of the first frame 10. An outer ring 15 a of the bearing 15 is fixed to the first frame 10, and an inner ring 15 b of the bearing 15 is fixedly connected to the rotating body 14. The second frame 11 is supported by the bearing 15 so as to be rotatable about the rotation axis J <b> 2 with respect to the first frame 10. Although not shown, the bearing 15 may be provided with an oil seal, for example, between the outer ring 15a and the inner ring 15b (the end facing the second frame 11).

  Although not shown in detail, the speed reducer 12 is composed of, for example, a harmonic drive (registered trademark). As is well known, the speed reducer 12 includes a wave generator comprising an elliptical cam and ball bearings on the outer periphery thereof, a cup-shaped flex spline (elastic gear) disposed on the outer periphery thereof, and a circular spline ( (Internal gear). At this time, the wave generator is fitted and connected to the distal end of the shaft 13 a of the servo motor 13, and the base end portion of the flexspline is fixed to the rotating body 14. The circular spline is fixed on the first frame 10 side.

  Thus, the driving force of the servo motor 13 is transmitted to the rotating body 14 and thus to the second frame 11 via the speed reducer 12. In this case, grease (or other lubricant) is accommodated in the speed reducer 12 and is lubricated. In addition, an O-ring for enhancing the sealing performance is provided on the overlapping surface of the other components, and grease is applied to the outer surface of the O-ring. This grease is composed of a base oil and an additive, and is usually semi-solid with viscosity. However, the base oil and the additive are separated due to changes in temperature and aging. However, the base oil component flows out.

  In the present embodiment, the following configuration is provided to prevent oil (base oil), which is a liquid component contained in the grease of the speed reducer 12, from leaking outside the joint portion 9. ing. That is, as shown in FIG. 2, the outer surface of the circular recess 10 a that is the outer peripheral side of the speed reducer 12 is formed on the surface of the first frame 10 facing the second frame 11 side (right side in the drawing). A first cylindrical wall 16 having a cylindrical shape centered on the rotation axis J2 is integrally provided so as to protrude from the end surface to the second frame 11 side (right side in the drawing). Yes.

  The bottom surface of the first frame 10 connected to the first cylindrical wall 16, that is, the end surface portion on the outer peripheral side of the circular recess 10 a, is located on the inner peripheral side portion of the first cylindrical wall 16 and the speed reducer 12 portion. A first felt member 17 serving as an annular first fibrous suction member for absorbing the base oil component of the grease leaking out from the grease is provided over the entire circumference. The first felt member 17 is an annular shape having a predetermined thickness dimension (for example, about 1 mm) and a radial width dimension (for example, about several mm) from a well-known felt material formed by compressing an aggregate of fiber materials. (Ring plate shape). The first felt member 17 is attached to the outer surface of the first frame 10 by, for example, adhesion so that the outer peripheral edge thereof is in contact with the inner peripheral surface of the first cylindrical wall 16.

  On the other hand, the surface of the second frame 11 facing the first frame 10 side (left side in the figure) has a cylindrical shape with the rotation axis J2 as the center, and the outer periphery of the first cylindrical wall 16 A second cylindrical wall 18 overlapping with a gap on the side is provided so as to protrude to the first frame 10 side. The outer surface of the second frame 11 facing the first frame 10 is located on the inner peripheral side of the second cylindrical wall 18 and on the outer peripheral side of the speed reducer 12, and the speed reducer 12 portion. A second felt member 19 as an annular second fibrous sucking member for absorbing the base oil component of the grease leaking out from the grease is provided over the entire circumference.

  The second felt member 19 is formed into an annular shape (ring plate shape) having a predetermined thickness dimension (for example, about 1 mm) and a radial width dimension (for example, about several mm) from the same material as the first felt member 17. It is comprised and it attaches to the outer surface of the 2nd frame 11 by adhesion | attachment, for example so that an outer peripheral part may contact | connect the proximal end inner peripheral surface of the 2nd cylindrical wall 18. FIG. At this time, as shown in FIG. 2, the inner diameter dimension of the second felt member 19 is configured to be slightly larger than the inner diameter dimension of the first felt member 17 and slightly smaller than the outer dimension. The outer dimension is slightly larger than the outer dimension of the first felt member 17. Therefore, as indicated by a symbol L in FIG. 2, the first felt member 17 and the second felt member 19 are provided at positions that partially overlap when viewed in the direction of the rotation axis J2.

  The first felt member 17 and the second felt member 19 can be attached by various methods such as bonding using a double-sided tape, fixing using screws, metal fittings, etc. in addition to bonding using an adhesive. In short, it is sufficient if it can be fixed so as not to move. Moreover, in the said structure, as shown in FIG. 2, the 1st felt member 17 and the 2nd felt member 19 are provided in non-contact with each other or the other side cylindrical walls 18 and 16 grade | etc.,. Of course, the first cylindrical wall 16 and the second cylindrical wall 18 are provided in a non-contact state with each other or with respect to the frames 11 and 10 on the other side.

  Next, the operation of the above configuration will be described. The grease provided to lubricate the speed reducer 12 described above is composed of a base oil and an additive, and usually has a semi-solid shape with viscosity. However, along with changes in temperature and aging, Then, the base oil and the additive are separated, and the base oil that is a liquid component flows out slightly. In the joint portion 9 of the robot body 1 having the above-described configuration, a small part of the liquid component (base oil) of the grease included in the speed reducer 12 (mechanism portion) causes, for example, centrifugal force when the robot body 1 is driven or Due to the action of gravity or the like, for example, through the bearing 15 portion (between the outer ring 15a and the inner ring 15b) or the like, it tries to leak to the outer peripheral side through the surface of the first frame 10 or the second frame 11.

  At this time, the base oil component that is about to leak along the surface of the first frame 10 is absorbed and captured by the annular first felt member 17 provided on the inner peripheral side of the first cylindrical wall 16. . In addition, the base oil component that is about to leak along the surface of the second frame 11 is absorbed and captured by the annular second felt member 19 provided on the inner peripheral side of the second cylindrical wall 18. . In this case, the film-like base oil component can be easily absorbed by the first felt member 17 and the second felt member 19.

  Here, both the first felt member 17 and the second felt member 19 can absorb a sufficient amount of base oil even if the thickness is small by sufficiently taking the dimension in the radial direction (width dimension). At this time, even when the second frame 11 repeats high-speed rotation, the centrifugal force at that time acts in the radial direction of the second felt member 19 and acts as a force in the compression direction on the surface of the second felt member 19. Therefore, the base oil once absorbed by the second felt member 19 does not ooze out easily. Similarly, even when the first frame 10 repeats high-speed rotation, the centrifugal force at that time acts in the radial direction of the first felt member 10 and acts as a force in the compression direction on the surface of the first felt member 17. Therefore, the base oil once absorbed by the first felt member 17 does not ooze out easily.

  Therefore, the base oil component of the grease that leaks from the speed reducer 12 and the like is surely captured by the first felt member 17 and the second felt member 19 and leaks outside beyond the first cylindrical wall 16 and the second cylindrical wall 18. Can be effectively prevented.

  By the way, according to the research by the present inventors, in the case of a small industrial robot having a portable weight of 20 kg or less as industrial equipment, for example, the base of grease that leaks in a standard maintenance period (for example, 5 years) in one joint. The amount of oil is at most 1 to 2 ml and can be sufficiently captured and absorbed by the felt member. Thus, for example, from the amount of liquid leakage that is experimentally or theoretically determined, the volume of the felt member (dimensions such as thickness and width) sufficient to absorb the liquid that may leak during a standard maintenance period, for example. The first felt member 17 and the second felt member 19 may be provided in an amount corresponding to the reverse calculation.

  At this time, the first felt member 17 and the second felt member 19 can be provided between each other or in a non-contact manner with respect to the opposite cylindrical walls 18, 16, etc., so that sliding resistance is generated. Absent. For reasons such as dimensional accuracy, even if the second felt member 19 contacts (slides) the tip of the first cylindrical wall 16 at the beginning of use, the sliding portion is easily worn. Since there is a gap, it eventually becomes a non-contact state at an early stage. Therefore, unlike the case with sliding such as an oil seal, it is possible to suppress the loss of driving torque due to sliding resistance.

  Since the first felt member 17 and the second felt member 19 are not expensive materials as compared with the oil seal, the members themselves can be manufactured at a relatively low cost. In addition, the first felt member 17 and the second felt member 19 are respectively provided in an annular shape, that is, a flat plate shape, with respect to a flat plate portion such as a bottom surface of the first frame 10 and an outer surface of the second frame 11. Therefore, as compared with the case where the felt member is attached to the curved surface, the mounting operation is facilitated. The first felt member 17 and the second felt member 19 can be easily positioned at the time of mounting by placing the outer peripheral edges along the inner peripheral surfaces of the first cylindrical wall 16 and the second cylindrical wall 18, respectively. Can do. In this case, by using the felt members 17 and 19 configured in an annular shape, there is no possibility that a gap is generated over the entire circumference. As a result, the overall cost can be reduced.

  Furthermore, unlike the oil seal, there is no sealing between the inner peripheral side and the outer peripheral side of the joint part 9, so that there is no pressure difference between the inside and the outside of the joint part 9, and the leaked base oil It is possible to prevent problems such as blowout and scattering. Further, since the first felt member 17 and the second felt member 19 are hidden by the first cylindrical wall 16 and the second cylindrical wall 18 and cannot be seen from the outside, the felt members 17 and 19 that have sucked a liquid such as oil. There is no such thing as seeing and getting worse.

  By the way, since there is no felt member or the like between the inner peripheral surface of the second cylindrical wall 18 and the outer peripheral surface of the first cylindrical wall 16, the second cylindrical wall 18 is connected to the outer periphery of the first cylindrical wall 16 correspondingly. It can be provided close to the surface, that is, with a relatively small diameter. As a result, it is possible to reduce the size in the diameter direction of the joint portion 9 as a whole without increasing so much.

  In the present embodiment, in particular, the first felt member 17 and the second felt member 19 are provided so as to partially overlap when viewed in the direction of the rotation axis J2. In the overlapping portion indicated by L, they are opposed to each other in the axial direction through a gap extending in the circumferential direction.

  At this time, even if the base oil leaked from the speed reducer 12 or the like tries to come out to the outer peripheral side through the gap between the first felt member 17 and the second felt member 19, the first felt The surfaces of the member 17 and the second felt member 19 are somewhat fluffy on the surface, and in the robot body 1, the joint part 9 itself often moves randomly in the vertical and horizontal directions. Accordingly, the base oil that has entered the gap between the first felt member 17 and the second felt member 19 easily touches the fuzzy fibers on the surface of either the first felt member 17 or the second felt member 19, Capillary action ensures that one of the felt members 17 and 19 is captured. As a result, it is possible to more effectively prevent the base oil from leaking out.

  As described above, according to the structure of the joint portion 9 of the present embodiment, the annular first felt member 17 is provided on the inner peripheral side of the first cylindrical wall 16 of the first frame 10 and the second frame 11 is provided. In addition, since the annular second felt member 19 is provided on the inner peripheral side of the second cylindrical wall 18, it is less likely to cause a loss of driving torque and is included in the speed reducer 12 while being relatively inexpensive. It is possible to effectively prevent the grease liquid component from leaking to the outside.

(2) Second Embodiment FIG. 4 shows a second embodiment of the present invention. The shoulder 3 (first frame 10) and the lower arm 4 (second frame 11) of the robot body 1 are shown. The structure of the joint part 31 which connects so that it can rotate relatively is shown. The second embodiment differs from the first embodiment in the configuration for preventing the base oil contained in the grease of the speed reducer 12 from leaking to the outside of the joint portion 31. Accordingly, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and only differences from the first embodiment will be described below.

  That is, a first cylindrical wall 32 having a cylindrical shape centered on the rotation axis J2 is located on the outer peripheral side portion of the circular recess 10a, which is the outer peripheral side of the speed reducer 12 of the first frame 10. , And are integrally provided so as to protrude from the end face to the second frame 11 side (right side in the figure). On the inner peripheral side of the first cylindrical wall 32, there is a first felt member 33 that is an annular first fibrous suction member for absorbing the base oil component of the grease leaking out from the speed reducer 12 portion. Are provided by bonding. The first felt member 33 has the same dimensions as the first felt member 17 in the first embodiment.

  On the other hand, of the outer surface of the second frame 11 facing the first frame 10, the outer peripheral portion of the circular convex portion 11a has a gap on the inner peripheral side of the first cylindrical wall 32, and A second felt member 34 as an annular second fibrous suction member for absorbing the base oil component of the grease leaking from the speed reducer 12 is provided over the entire circumference. The second felt member 34 is made of a material equivalent to the first felt member 33 into an annular shape (ring plate shape) having a predetermined thickness dimension (for example, about 1 mm) and a radial width dimension (for example, about several mm). Here, the outer diameter of the second felt member 34 is equal to the inner diameter of the first felt member 33. The second felt member 34 is attached to the outer surface of the second frame 11 by, for example, adhesion so that the inner peripheral edge thereof is in contact with the outer peripheral surface of the base end side of the circular convex portion 11a.

  Also in the structure of the joint portion 31 having the above-described configuration, the base oil component that is about to leak along the surface of the first frame 10 is also an annular first provided on the inner peripheral side of the first cylindrical wall 32. It is absorbed and captured by the felt member 33. In addition, the base oil component that is about to leak along the surface of the second frame 11 is absorbed and captured by the annular second felt member 34 provided on the outer peripheral side of the circular convex portion 11a. In this case, the film-like base oil component can be easily absorbed by the first felt member 33 and the second felt member 34.

  Also in this case, as in the first embodiment, the base oil that has entered the gap between the first felt member 33 and the second felt member 34 is the first felt member 33 or the second felt member 34. It is easy to touch the fluffy fibers on one of the surfaces of the two, and it is surely captured by one of the felt members 33 and 34 by capillary action. Therefore, the first felt member 33 and the second felt member 34 can reliably capture the base oil component of the grease that leaks from the speed reducer 12 and the like, and effectively prevent the grease from leaking outside. .

  At this time, the first felt member 33 and the second felt member 34 can be provided between each other or in a non-contact manner with respect to the counterpart member or the like, so that sliding resistance does not occur. For example, the first felt member 33 and the second felt member 34 are easily worn at the sliding part even if they are contacted (sliding) at the beginning of use due to dimensional accuracy and the like. After all, it will be in a non-contact state early. Therefore, unlike the case with sliding such as an oil seal, it is possible to suppress the loss of driving torque due to sliding resistance. Further, since the inner periphery side and the outer periphery side of the joint portion 31 are not sealed unlike an oil seal, there is no pressure difference between the inside and the outside of the joint portion 31, and the leaked base oil It is possible to prevent problems such as blowout and scattering.

  The first felt member 33 and the second felt member 34 are both provided in an annular shape, that is, a flat plate shape, with respect to a flat plate portion such as the bottom surface of the first frame 10 and the outer surface of the second frame 11. As a result, the attachment work becomes easier as compared with the case of attaching the felt member to the curved surface. Further, in the present embodiment, by making the inner diameter dimension of the first felt member 33 and the outer diameter dimension of the second felt member 34 equal, for example, from the plate-like felt, the first felt member 33 and The material of the second felt member 34 can be efficiently taken, and accordingly, the cost of the member itself can be reduced. Accordingly, the overall cost can be reduced.

  As a result, also in the structure of the joint portion 31 of the second embodiment, the loss of drive torque is less likely to occur, and the base oil component of grease is effectively leaked to the outside while being relatively inexpensive. Can be prevented. Moreover, in the present embodiment, in particular, the material of the first felt member 33 and the second felt member 34 can be efficiently taken, and the cost can be reduced accordingly. Further, since the second cylindrical wall 18 in the first embodiment is omitted, the configuration is simplified, and the merit that the entire joint portion 31 can be reduced in the diameter direction can be obtained.

(3) Third Example and Other Examples Next, a third example of the present invention will be described with reference to FIGS. FIG. 5 shows a main configuration of the joint portion 41 according to the present embodiment, in which the first frame 10 and the second frame 11 of the robot main body 1 are connected so as to be relatively rotatable. The third embodiment differs from the first embodiment in that there is a gap between the first felt member 17 provided on the first frame 10 and the second felt member 19 provided on the second frame 11. A thin plate-like partition member 42 for separating the first felt member 17 and the second felt member 19 is provided in the facing portion. Accordingly, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and only differences from the first embodiment will be described below.

  In this embodiment, the partition member 42 is formed in a ring shape from a hard film (thin plate) made of plastic such as PET or acrylic having a thickness dimension of about 0.1 mm. In this case, it is desirable that the partition member 42 has a smooth surface and is relatively light, and a plastic thin plate can be employed, and can be manufactured by press working or the like. The partition member 42 has an outer diameter that is equivalent to the outer diameter of the second felt member 19 (the inner diameter of the second cylindrical wall 18), an inner diameter that is slightly smaller than the inner diameter of the second felt member 19, and The inner peripheral edge portion is formed to be slightly curved toward the second frame 11 side (second felt member 19 side).

  The partition member 42 is located on the surface side of the second felt member 19 (the side facing the first felt member 17), and the outer peripheral edge thereof is fitted so as to be in pressure contact with the inner peripheral surface of the second cylindrical wall 18. . Thus, the partition member 42 covers the entire surface side of the second felt member 19 on the second frame 11 side, that is, the entire portion facing the first felt member 17 so as to cover the second felt member 19. And the surface of the first felt member 16 are separated from each other. At this time, the inner peripheral edge of the partition member 42 is slightly curved toward the second frame 11, thereby preventing the edge of the partition member 42 from contacting the first felt member 17 or the second felt member 19. , Preventing fiber waste from coming out.

  Here, as shown in FIG. 6, when the first felt member 17 and the second felt member 19 are arranged facing each other with a gap, the gap is considered from the viewpoint of reducing the size of the entire joint. Is desirably as small as possible (see FIG. 6A). However, since the surfaces of the first felt member 17 and the second felt member 19 are somewhat fuzzy, if the gap between them is small, the second felt member 17 is less than the first felt member 17. When 19 is rotated, fluffy fibers on the surface are entangled (see FIG. 6B), and the fibers in the entangled part are torn off from the felt members 17 and 19, and dust D consisting of fiber waste is generated. (See FIG. 6C).

  On the other hand, in the present embodiment, the fibers on the surface of the first felt member 17 and the fibers on the surface of the second felt member 19 are separated by the partition member 42 and can be prevented from contacting directly. Therefore, the gap between the first felt member 17 and the second felt member 19 can be reduced, and the fibers can be entangled with each other and the generation of dust D can be prevented.

  At this time, in the case where the first felt member 17 and the second felt member 19 are arranged to face each other, the fuzz portions on the surface must not be in contact with each other. According to the experiment of the present inventor, when the thickness of the felt member is 1 mm, the fluff is about 0.5 mm, and when the thickness of the felt member is 2 mm, the fluff is about 0.8 mm. ing. When the partition member 42 is sandwiched, when the partition member 42 is made of a synthetic resin film, the thickness can be realized at a level of several tens of μm to 100 μm. Thereby, the clearance gap between the 1st felt member 17 and the 2nd felt member 19 can be made small enough.

  As a result, also in the structure of the joint portion 41 of the third embodiment, as in the first embodiment, it is difficult to cause a loss of driving torque and is relatively inexpensive, but the base oil of grease Leakage of components to the outside can be effectively prevented. In addition to that, the gap between the first felt member 17 and the second felt member 19 is reduced while suppressing the generation of dust D due to the fibers on the surfaces of the first and second felt members 17 and 19. As a result, the entire joint 41 can be reduced in size in the axial direction.

  In the third embodiment described above, the partition member 42 is made of a plastic thin plate, but it is also possible to employ a thin plate made of metal (having a certain degree of plate ductility). In addition, the annular partition member may be fixed (fitted) to either one of the inner peripheral edge or the outer peripheral edge with respect to either one of the frames 10 and 11, or in a retaining state. It may be fitted with a little play after ensuring.

  For example, an annular partition member may be attached to the first frame 10 side by extending the first cylindrical wall 16 a little further and fitting it to the inner peripheral surface thereof. An annular partition member can be fitted to the outer peripheral surface of the circular convex portion 11. Or you may make it stick on the surface of one of the felt members 17 and 19 with an adhesive agent. However, the partition member has secured a gap through which the liquid component passes on the inner peripheral side or the outer peripheral side so as not to disturb the absorption of the liquid component of the grease or lubricant by the first felt member 17 and the second felt member 19. It is important to place in.

  Further, in each of the above-described embodiments, the felt member is employed as the fibrous sucking member. However, as the fibrous sucking member, any member that can absorb liquid and can be molded into a predetermined shape is used. Besides, it is also possible to employ non-woven fabric, paper, cotton, etc., and further employ a porous member such as a plastic sponge.

  In the first embodiment, the first felt member 17 and the second felt member 19 that are both annular are configured so as to partially overlap when viewed in the direction of the rotation axis J2. You may comprise so that a radial dimension and the internal diameter dimension of a 2nd felt member may be made equivalent. Similarly, in the second embodiment, the inner diameter dimension of the first felt member 33 and the outer diameter dimension of the second felt member 34 are made equal, but the first felt member and the second felt member May be configured to partially overlap when viewed in the direction of the rotation axis J2.

  Further, in each of the above-described embodiments, the joint portions 9, 31, 41 that connect the shoulder portion 3 and the lower arm 4 so as to be relatively rotatable in the robot body 1 are given as specific examples. Of course, the present invention can be applied to other joints of the robot body 1. In this case, the joint part structure of the present invention can be provided on all or part of the plurality of joint parts. In each of the above embodiments, the first frame 10 is the fixed side (the side having the servo motor 13), and the second frame 11 is the rotating side (the side relatively rotated by the servo motor 13). Any relationship may be used as long as it is relatively rotationally coupled with the second frame.

  In each of the above embodiments, the mechanical unit includes the speed reducer 12 made of a harmonic drive and the bearing 15 made of a cross roller bearing. As specific configurations of the speed reducer 12 and the bearing 15, Various modifications are possible, and a mechanism having another rotation transmission mechanism or a mechanism having only a bearing may be used. The mechanism portion is not limited to grease but may have another lubricant, and according to the present invention, it is possible to prevent leakage of liquid components. Furthermore, the present invention is not limited to small industrial robots, but can be applied to general industrial equipment such as large industrial robots and production apparatuses that perform dedicated operations. Therefore, it can be implemented with appropriate modifications.

  In the drawings, 1 is a robot body (industrial equipment), 9, 31, 41 are joint parts, 10 is a first frame, 11 is a second frame, 12 is a speed reducer (mechanism part), 15 is a bearing, 16, 32 Is a first cylindrical wall, 17 and 33 are first felt members (first fibrous suction members), 18 is a second cylindrical wall, 19 and 34 are second felt members (second fibrous suction members), and 42 is a partition. The member is shown.

Claims (5)

A joint part structure of an industrial device in which a first frame and a second frame that are arranged to face each other in the direction of the rotational axis are connected so as to be relatively rotatable via a mechanism having grease or a lubricant. In
The first frame is provided with a first cylindrical wall that is located on the outer peripheral side of the mechanism portion and has a cylindrical shape centered on the rotation axis so as to protrude toward the second frame,
Of the bottom surface of the first frame that is continuous with the first cylindrical wall, an inner peripheral side portion of the first cylindrical wall absorbs the grease or the liquid component of the lubricant that leaks from the mechanism portion. The first fibrous suction member is provided over the entire circumference,
Of the outer surface facing the first frame side of the second frame, a portion located on the outer peripheral side of the mechanism portion is a circle for absorbing the liquid component of the grease or lubricant leaking from the mechanism portion. A joint structure for industrial equipment, characterized in that an annular second fibrous suction member is provided over the entire circumference. The second frame has a cylindrical shape centered on the rotational axis, and a second cylindrical wall that overlaps with an outer peripheral side of the first cylindrical wall with a gap is provided so as to protrude to the first frame side. And
2. The annular second fibrous suction member is provided on the inner peripheral side portion of the second cylindrical wall of the bottom surface continuous with the second cylindrical wall over the entire circumference. The joint structure of the described industrial equipment.   The joint of an industrial equipment according to claim 1 or 2, wherein the first fibrous suction member and the second fibrous suction member are provided so as to partially overlap each other when viewed in the rotational axis direction. Part structure.   A thin plate shape for separating the first fibrous suction member and the second fibrous suction member at a portion where the first fibrous suction member and the second fibrous suction member face each other with a gap. The joint part structure of the industrial equipment according to claim 3, wherein a partition member is arranged.   The industrial apparatus according to claim 1 or 2, wherein one of the first fibrous suction member and the second fibrous suction member has an outer diameter dimension equal to an inner diameter dimension of the other. The joint structure.

Images