Structure of a driving unit for relatively rotating a plurality of structural units and robot having joints

Abstract

A joint structure is provided that suppresses deterioration or damage of a sealing member disposed inside the joint. The joint enables a first structural portion (9) and a second structural portion (10) to rotate relative to each other. The joint structure comprises: an oil seal (35) disposed in a gap portion (71); and a labyrinth member (41) disposed on the outer surfaces of the first structural portion (9) and the second structural portion (10). The labyrinth member (41) has a passage (69) communicating with the gap portion (71). The labyrinth member (41) is formed so as to be mountable to the outer surface of the first structural portion (9) and the outer surface of the second structural portion (10). Furthermore, the labyrinth member (41) is formed so as to be removable from the first structural portion (9) and the second structural portion (10).

Description

Technical Field

[0001] The present invention relates to a structure of a driving unit for relatively rotating a plurality of structural units and a robot including joints. Background Art

[0002] Conventional technology has known devices equipped with a drive unit for rotating one structural component relative to another. For example, a multi-jointed robot comprises structural components such as an arm and wrist connected by joints. The joints include a mechanism for rotating one structural component relative to another. By changing the orientation of one structural component relative to another, the robot's position and posture can be changed.

[0003] Devices equipped with a drive unit are used in a variety of environments. An electric motor and a reducer for driving the structural members are arranged inside the drive unit. In addition, wiring and electronic equipment are arranged inside the drive unit. In the drive unit, gaps are formed between the structural members so that one structural member can rotate relative to the other structural members. When foreign matter invades from the gap, the equipment or electrical components arranged inside the drive unit may malfunction. Therefore, the drive unit preferably has a structure that prevents foreign matter from invading the inside. In addition, when a fluid such as lubricating oil is arranged inside the drive unit, it is preferably provided with a structure that prevents the fluid from flowing out.

[0004] In the prior art, it is known to dispose O-rings or the like between mutually fixed components to prevent foreign matter from entering the interior of a device and to prevent fluid from leaking out of the device. It is also known to dispose oil seals around rotating components (e.g., Japanese Patent Application Laid-Open No. 11-254377, Japanese Patent Application Laid-Open No. 2003-172457, and Japanese Utility Model Registration No. 3112976).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 11-254377

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2003-172457

[0009] Patent Document 3: Japanese Utility Model Registration No. 3112976 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] Sealing components such as oil seals are exposed to the outside air in order to be arranged in the gap portion inside the drive unit. The sealing components come into contact with various foreign matter contained in the outside air. For example, in a robot that cleans metal plates, food, or containers, there is a case where the cleaning liquid intrudes into the gap portion and reaches the oil seal. In the case where the cleaning liquid contains chemical components for improving the cleaning ability, there is a case where the sealing component is degraded by the chemical components. Alternatively, even if the cleaning liquid does not directly contact the sealing component, there is a case where the mist of the cleaning liquid intrudes into the gap portion and contacts the sealing component.

[0012] Alternatively, foreign matter that reaches the sealing member may include not only liquids but also solids such as metal powder. For example, if metal powder passes through the gap and reaches the sealing member, it may become lodged between the sealing member and the member it contacts, potentially damaging the sealing member.

[0013] Foreign matter comes in a wide variety of types. No sealing member is made of a material that is resistant to all types of foreign matter. To adapt the device to various environments, the material of the sealing member must be selected based on the environment in which the device is used. Specifically, a sealing member made of a material suitable for foreign matter that may intrude into the drive unit is preferably selected.

[0014] However, there are cases where the type of foreign matter that reaches the sealing member changes. In this case, it is necessary to replace the sealing member with a material corresponding to the type of foreign matter. For example, if the type of cleaning fluid is changed during the cleaning process, it is necessary to replace the sealing member with a material that does not degrade with the cleaning fluid. Alternatively, it may be discovered after the device has been used that contact with the foreign matter will cause the sealing member to degrade. In this case, the sealing member also needs to be replaced.

[0015] The sealing member is disposed inside the driving unit. Therefore, if the sealing member deteriorates or is damaged, a large amount of work is required to replace the sealing member. In addition, the device needs to be stopped for a long time.

[0016] Solutions for solving problems

[0017] A technical solution disclosed herein is a structure of a driving portion that causes a first structural portion and a second structural portion opposite to the first structural portion to rotate relative to each other. The structure of the driving portion comprises: a sealing member, which is arranged in a gap portion serving as a space between the first structural portion and the second structural portion; and a passage constituting member, which is arranged on the outer surface of at least one of the first structural portion and the second structural portion. The sealing member is fixed to the first structural portion and is in contact with the second structural portion. The gap portion has an opening portion communicating with the outside of the driving portion. The passage constituting member has a shape that forms a passage communicating with the opening portion. The passage constituting member is formed so as to be mountable to at least one of the outer surface of the first structural portion and the outer surface of the second structural portion. Furthermore, the passage constituting member is formed so as to be removable from the first structural portion and the second structural portion.

[0018] Another technical solution disclosed herein is a robot comprising: a first structural member including a first shell; a second structural member including a second shell; and a joint portion that rotates the second structural member relative to the first structural member. The robot comprises a passage constituting member, which is arranged on the outer surface of the joint portion. The joint portion comprises: a reducer connected to the motor; and a sealing member that suppresses the outflow of lubricating oil inside the reducer. The shell of the joint portion is composed of at least one of the first shell and the second shell. A gap portion is formed inside the joint portion, and the gap portion has an opening portion that communicates with the outside of the joint portion. The sealing member is arranged in the gap portion, fixed to the first shell or a member fixed to the first shell, and in contact with the second shell or a member fixed to the second shell. The passage constituting member has a shape that forms a passage that communicates with the opening portion. The passage constituting member is formed so as to be mountable to the outer surface of the joint portion. Moreover, the passage constituting member is formed so as to be removable from the outer surface of the joint portion.

[0019] Effects of the Invention

[0020] According to the technical aspects of the present disclosure, it is possible to provide a structure of a driving unit and a robot that suppresses degradation or damage of a sealing member disposed inside the driving unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a side view of the robot device according to the embodiment.

[0022] Figure 2 This is a schematic partial cross-sectional view of a joint portion where a first labyrinth element is arranged according to the embodiment.

[0023] Figure 3 It is an enlarged schematic cross-sectional view of a portion where the first labyrinth member is arranged.

[0024] Figure 4 This is a perspective view of the first labyrinth component.

[0025] Figure 5 This is a perspective view of the first annular member of the first labyrinth member.

[0026] Figure 6 It is an enlarged perspective view of a portion where the divided members of the first annular member are in contact with each other.

[0027] Figure 7 This is a perspective view of the second annular member of the first labyrinth member.

[0028] Figure 8 It is an enlarged perspective view of a portion where the divided members of the second annular member are in contact with each other.

[0029] Figure 9 It is an enlarged schematic cross-sectional view of a joint portion of a comparative example.

[0030] Figure 10 This is a perspective view of the first annular member of the second labyrinth member according to the embodiment.

[0031] Figure 11 It is an enlarged perspective view of a portion where the divided members of the first annular member are in contact with each other.

[0032] Figure 12 This is a perspective view of the second annular member of the second labyrinth member.

[0033] Figure 13 It is an enlarged perspective view of a portion where the divided members of the second annular member are in contact with each other.

[0034] Figure 14 This is an enlarged schematic cross-sectional view of a joint with grease filled in the gap.

[0035] Figure 15 This is a schematic partial cross-sectional view of a joint portion in which a gas supply pipe is connected to the gap.

[0036] Figure 16 It is an enlarged schematic cross-sectional view of a portion where the first labyrinth member and the gas supply pipe are arranged.

[0037] Figure 17 It is an enlarged schematic cross-sectional view of a portion where the third labyrinth member is arranged in the embodiment.

[0038] Figure 18 It is an enlarged schematic cross-sectional view of a portion where the fourth labyrinth member is arranged in the embodiment.

[0039] Figure 19 This is a schematic partial cross-sectional view of a joint portion where the first labyrinth member is arranged on the outer peripheral surface of the speed reducer.

[0040] Figure 20 This is an enlarged schematic cross-sectional view of the portion where the first labyrinth member is fixed to the speed reducer. DETAILED DESCRIPTION

[0041] Reference Figures 1 to 20 , the structure of the driving unit and the robot of the embodiment will be described. In this embodiment, a robot is taken as an example of a device including a driving unit for description.

[0042] Figure 1 This is a schematic diagram of a robot device according to this embodiment. Robot device 3 includes a hand 2 serving as a working tool and a robot 1 that moves hand 2. Robot 1 according to this embodiment is a multi-jointed robot comprising multiple joints 18a, 18b, and 18c. Robot 1 includes multiple rotatable components. Each component is configured to rotate about drive axes J1 to J6.

[0043] The robot 1 includes a base portion 14 fixed to a setting surface and a rotating base 13 supported by the base portion 14. The rotating base 13 rotates around a drive axis J1 relative to the base portion 14. The robot 1 includes an upper arm 11 and a lower arm 12. The lower arm 12 is supported by the rotating base 13 so as to rotate around a drive axis J2 relative to the rotating base 13. The upper arm 11 is supported by the lower arm 12 so as to rotate around a drive axis J3 relative to the lower arm 12. Furthermore, the upper arm 11 rotates around a drive axis J4. The robot 1 includes a wrist 15 supported by the upper arm 11. The wrist 15 rotates around a drive axis J5. In addition, the wrist 15 includes a flange 16 that rotates around a drive axis J6. The hand 2 is fixed to the flange 16.

[0044] Thus, the robot 1 of this embodiment includes a base 14, a rotating base 13, a lower arm 12, an upper arm 11, and a wrist 15 as structural components. The robot of this embodiment has six drive axes, but is not limited to this configuration. A robot that utilizes any mechanism to change position and posture can be employed. Furthermore, the work tool of this embodiment is a hand for gripping a workpiece, but is not limited to this configuration. An operator can attach to the robot 1 any work tool that corresponds to the work being performed by the robot.

[0045] Figure 2 2 is a schematic partial cross-sectional view showing the structure of the first driving portion of this embodiment. Figure 2 It is a cross-sectional view of the joint portion 18 a serving as a driving portion that rotates the lower arm 12 relative to the rotary base 13 around the driving axis J2 .

[0046] In this embodiment, the rotating base 13 functions as the first structural member, and the lower arm 12 functions as the second structural member. The joint portion 18a includes a motor 21 for rotating the lower arm 12 and a reducer 31 connected to the motor 21. The rotating base 13 includes a first housing 13a, which contains the motor 21, the reducer 31, and the like. A cavity is formed within the housing 13a. The lower arm 12 includes a second housing 12a, which has a cavity formed therein. Electrical wires or signal lines are disposed within the cavity within the housing 12a.

[0047] The motor 21 is fixed to the housing 13a of the rotating base 13. The speed reducer 31 of this embodiment includes a fixed portion 31a fixed to the housing 13a of the rotating base 13, and a movable portion 31b fixed to the housing 12a of the lower arm 12. The fixed portion 31a does not rotate when the lower arm 12 rotates. On the other hand, the movable portion 31b rotates together with the lower arm 12.

[0048] The motor 21 has an output shaft 21a. The rotational force of the output shaft 21a is transmitted to the gear 31c of the movable portion 31b of the speed reducer 31 via the gears 22 and 23. The gear disposed inside the fixed portion 31a engages with the gear disposed inside the movable portion 31b, causing the movable portion 31b to rotate relative to the fixed portion 31a.

[0049] The movable portion 31b is formed into a cylindrical shape. The fixed portion 31a is formed into a cylindrical shape so as to surround the movable portion 31b. A cylindrical member 25 extends through the center of the movable portion 31b. The cylindrical member 25 is fixed to the housing 12a of the lower arm 12. Electrical wires and signal lines are inserted into the interior of the cylindrical member 25.

[0050] Joint 18a, acting as a driving unit, causes the first structure and the second structure, which opposes the first structure, to rotate relative to each other. The housing 13a of the rotating base 13 and the fixed portion 31a of the speed reducer 31 correspond to the first structure 9. Furthermore, the housing 12a of the lower arm 12 and the movable portion 31b of the speed reducer 31 correspond to the second structure 10, which rotates integrally. When the rotational force of the motor 21 is transmitted, the second structure 10, including the movable portion 31b, rotates relative to the first structure 9, including the fixed portion 31a. In other words, the lower arm 12 rotates relative to the rotating base 13.

[0051] Figure 3 : is an enlarged schematic cross-sectional view of a portion where the first labyrinth member and the sealing member are arranged in this embodiment. Figure 2 and Figure 3The housing of the joint portion 18a is composed of the housing 13a of the rotating base 13 and the housing 12a of the lower arm 12. A gap portion 71 is formed inside the joint portion 18a as a space between the first structural portion 9 and the second structural portion 10. In the structure of the first drive portion, the gap portion 71 is composed of a space surrounded by the housing 12a, the housing 13a, and the speed reducer 31. The gap portion 71 is connected to the outside of the joint portion 18a through an opening portion 71a formed by the first structural portion 9 and the second structural portion 10 facing each other.

[0052] In the structure of the first drive unit, the housing 13a of the rotating base 13 and the housing 12a of the lower arm 12 are formed to cover the outer peripheral surface of the speed reducer 31. In other words, the outer peripheral surface of the speed reducer 31 is disposed within the housings 13a and 12a, and is not exposed to the outside. This structure prevents the speed reducer 31 from coming into contact with foreign matter such as cleaning fluid or metal powder. This prevents the surface of the speed reducer 31 from being corroded by chemical components in the liquid or damaged by solid matter such as metal powder.

[0053] The joint portion 18a includes a sealing member 82 disposed between the housing 13a and the fixed portion 31a. In addition, the joint portion 18a includes a sealing member 81 disposed between the housing 12a and the movable portion 31b. The sealing members 81 and 82 can be composed of O-rings or the like. Furthermore, the joint portion 18a includes an oil seal 35 as a sealing member disposed in the gap portion 71. The oil seal 35 suppresses the lubricating oil disposed inside the speed reducer 31 from flowing out to the outside of the speed reducer 31. The oil seal 35 of the present embodiment is configured in a manner that suppresses the lubricating oil from flowing out from between the fixed portion 31a and the movable portion 31b of the speed reducer 31 to the outside of the speed reducer 31.

[0054] The oil seal 35 of this embodiment is formed into an annular shape so as to surround the movable portion 31b. The oil seal 35 includes a lip portion 35a formed from an elastic member such as rubber and a support member 35b that supports the lip portion 35a. The support member 35b is formed, for example, from metal. As indicated by arrow 91, the oil seal 35 includes a spring 35c that presses the lip portion 35a radially inward.

[0055] The oil seal 35 is fixed to the fixed portion 31a of the speed reducer 31 included in the first structural portion 9. The oil seal 35 contacts the movable portion 31b of the speed reducer 31 included in the second structural portion 10. Specifically, the oil seal 35 is fixed to the fixed portion 31a fixed to the first housing 13a and contacts the movable portion 31b fixed to the second housing 12a. When the movable portion 31b rotates relative to the fixed portion 31a, the oil seal 35 slides against the outer circumferential surface of the movable portion 31b. The lip portion 35a contacts the outer circumferential surface of the movable portion 31b, thereby preventing lubricating oil from leaking out from between the movable portion 31b and the fixed portion 31a.

[0056] The member where the sealing member is disposed is not limited to this embodiment. For example, the oil seal can be fixed to the first housing 13a. Furthermore, the oil seal can be disposed so as to contact the second housing 12a.

[0057] In the structure of the first drive unit of this embodiment, a first labyrinth member 41 serving as a passage-forming member is disposed on the outer surface of the joint portion 18a. The labyrinth member 41 can be attached to the outer surface of at least one of the first structural portion 9 and the second structural portion 10. The labyrinth member 41 has a shape that forms a passage 69 that communicates with the opening 71a of the gap 71.

[0058] The labyrinth member 41 is disposed on the outer circumferential surface of the joint portion 18a. The first labyrinth member 41 includes a first annular member 42 formed to surround the outer circumferential surface of the housing 13a. The first annular member 42 is fixed to the outer surface of the housing 13a included in the first structural portion 9. The first annular member 42 functions as a first opposing member fixed to the first structural portion 9.

[0059] The labyrinth member 41 also includes a second annular member 43 formed to surround the outer peripheral surface of the housing 12a. The second annular member 43 is fixed to the outer surface of the housing 12a included in the second structural portion 10. The second annular member 43 is arranged so as to face the first annular member 42. The second annular member 43 functions as a second opposing member fixed to the second structural portion 10.

[0060] The labyrinth member 41 includes a passage 69 that communicates with the gap 71. In the first labyrinth member 41, the passage 69 is formed by an area sandwiched between the first annular member 42 and the second annular member 43. The passage 69 has a passage cross-sectional area that is smaller than the passage cross-sectional area of ​​the opening 71a. In this embodiment, the width d2 of the passage 69 is formed to be smaller than the width d1 of the opening 71a in the cross-sectional shape. The passage 69 functions as a labyrinth passage with a smaller passage cross-sectional area. Alternatively, the passage 69 may be formed to have a passage cross-sectional area that is larger than the passage cross-sectional area of ​​the opening 71a.

[0061] Figure 4 2 is a perspective view of a first labyrinth member according to this embodiment. Figure 5 3D is a perspective view of the first annular member of the first labyrinth member. Figure 6 , an enlarged perspective view of a portion where a plurality of segmented members of the first annular member face each other is shown. Figures 4 to 6 The first annular member 42 is formed into an annular shape. The first annular member 42 includes a plurality of segmented members 42a whose side surfaces are formed into an arc shape. The first annular member 42 is formed by the plurality of segmented members 42a contacting each other.

[0062] The split member 42a has a step portion 42aa. A double-sided tape 44 is disposed on the inner peripheral surface of the split member 42a in a region avoiding the step portion 42aa. The first annular member 42 is fixed to the housing 13a by the double-sided tape 44.

[0063] Figure 7 3D is a perspective view of the second annular member of the first labyrinth member. Figure 8 , an enlarged perspective view of a portion where a plurality of split members of the second annular member face each other is shown. Figure 4 、 Figure 7 as well as Figure 8 The second annular member 43 is formed into a circular ring shape. The second annular member 43 includes a plurality of segmented members 43a whose side surfaces are formed into circular arc shapes. The second annular member 43 is formed by the plurality of segmented members 43a contacting each other. Double-sided tape 44 is disposed on the inner circumferential surface of the segmented members 43a. The second annular member 43 is fixed to the housing 12a using the double-sided tape 44.

[0064] The split components 42a and 43a of this embodiment are fixed to the outer peripheral surfaces of the first housing 13a and the second housing 12a using double-sided tape 44. Therefore, the labyrinth component 41 can be easily attached to or removed from the outer surface of the joint portion 18a. Furthermore, while the annular component of this embodiment is composed of two split components, this is not limited to this configuration. The annular component may also include three or more split components.

[0065] Reference Figures 3 to 5 The passage 69 of the labyrinth member 41 is formed by the region where the step portion 42aa of the first annular member 42 and the second annular member 43 face each other. The passage 69 is formed so as to communicate with the opening 71a of the gap 71.

[0066] The labyrinth member 41 is configured to be attachable to the outer surface of the joint portion 18a. In particular, the labyrinth member 41 is configured to be attachable to the joint portion 18a after the robot 1 begins use. Furthermore, the labyrinth member 41 is configured to be removable from the outer surface of the joint portion 18a. Specifically, the labyrinth member 41 is configured to be removable from the first structural portion 9 and the second structural portion 10.

[0067] Figure 9 shows an enlarged schematic cross-sectional view of the joint portion of a comparative example robot. The labyrinth components of this embodiment are not configured in the joint portion of the comparative example robot. As indicated by arrow 92, foreign matter such as cleaning fluid and metal powder present outside the robot can easily enter gap 71 through opening 71a. In other words, foreign matter can easily reach oil seal 35. As a result, oil seal 35 may deteriorate or be damaged.

[0068] Reference Figure 3In contrast, in the structure of the first drive unit of this embodiment, the first labyrinth member 41 is disposed in the opening 71a of the gap 71. The gap 71 is connected to the passage 69. Therefore, foreign matter can be prevented from entering the passage 69 as indicated by arrow 92. Foreign matter such as cleaning fluid and metal powder present outside the joint 18a can be effectively prevented from entering the gap 71 and reaching the oil seal 35. As a result, damage or degradation of the oil seal 35 can be suppressed.

[0069] In the drive unit structure of this embodiment, since foreign matter is prevented from reaching the oil seal 35, the oil seal 35 does not need to be made of a material that is resistant to foreign matter intruding into the drive unit. In other words, an oil seal made of a general-purpose material can be used instead of a costly one. For example, if the cleaning fluid contains chemicals that corrode the oil seal, the oil seal material can be selected without considering chemical resistance.

[0070] Furthermore, the labyrinth component 41 in this embodiment is designed to be attachable to and detachable from the joint portion 18a. In particular, it can be attached to the joint portion 18a after the robot 1 begins use. For example, the labyrinth component can be installed after the robot begins use if it is discovered that the oil seal is deteriorating due to foreign matter. Furthermore, the labyrinth component can be installed if the robot's operating environment changes. For example, the labyrinth component can be installed if the cleaning fluid is changed from one that does not contain chemicals that degrade the oil seal to one that does.

[0071] Furthermore, the labyrinth component can be removed when no longer needed. For example, it can be removed when no longer requiring cleaning fluid. Alternatively, the labyrinth component can be replaced based on changes in the robot's operating environment. For example, a labyrinth component made of a different material can be replaced with a different type of cleaning fluid. This allows the labyrinth component to be installed or replaced before the sealing member degrades or becomes damaged.

[0072] In this embodiment, the passage 69 of the labyrinth member 41 is formed to extend in a direction intersecting the direction in which the gap 71 extends at the opening 71a. In this embodiment, the passage 69 is formed to extend perpendicularly to the direction in which the portion of the gap 71 communicating with the outside extends. By forming the passage 69 of the labyrinth member 41 so as not to be parallel to the portion at the outlet of the gap 71, it is possible to effectively prevent foreign matter from entering the gap 71 through the passage 69.

[0073] The first labyrinth component 41 is fixed to the outer peripheral surface of the structural member of the robot 1 using double-sided tape 44, but the present invention is not limited to this embodiment. The labyrinth component may be fixed to the structural member using fastening members such as bolts.

[0074] Figure 102 is a perspective view of the first annular member of the second labyrinth member according to the present embodiment. Figure 11 , an enlarged perspective view of a portion of the second labyrinth member where the split members of the first annular member are fixed to each other is shown. Figure 10 and Figure 11 The second labyrinth member includes a first annular member and a second annular member. The first annular member 46 of the second labyrinth member includes a plurality of segmented members 46a. The segmented members 46a have stepped portions 46aa. Furthermore, bent portions 46ab are formed at the ends of the segmented members 46a. The two bent portions 46ab are secured to each other using bolts 48 and nuts 49.

[0075] Figure 12 2 is a perspective view of the second annular member of the second labyrinth member according to the present embodiment. Figure 13 , an enlarged perspective view of a portion where the split members of the second annular member are fixed to each other in the second labyrinth member is shown. Figure 12 and Figure 13 The second annular member 47 includes a plurality of segmented members 47a. The segmented members 47a each include an engaging portion 47aa. The two engaging portions 47aa are fixed to each other by a bolt 48 and a nut 49.

[0076] In the second labyrinth component, after the split components are arranged so as to sandwich the housing of the joint, they are then secured to each other using fastening components. The first annular component 46 and the second annular component 47 can be secured to the outer peripheral surface of the structural component of the robot 1. By tightening the bolts 48, the individual annular components 46 and 47 of the second labyrinth component can be easily secured. Furthermore, by loosening the bolts 48, the individual annular components 46 and 47 of the second labyrinth component can be easily removed. The rest of the structure, function, and effects of the second labyrinth component are the same as those of the first labyrinth component.

[0077] The labyrinth component can be formed of any material. For example, the labyrinth component can be formed of resin or metal. When the labyrinth component is formed of resin, the labyrinth component can be formed by injection molding of the resin.

[0078] Furthermore, the annular member included in the labyrinth structure may also be formed of a deformable strip-shaped member. For example, a deformable metal or rubber member may be secured to the outer circumference of the first shell 13a and the outer circumference of the second shell 12a using double-sided tape. Alternatively, a fastening member may be used to secure the strip-shaped member to at least one of the first structural portion 9 and the second structural portion 10.

[0079] Figure 14FIG2 shows an enlarged schematic cross-sectional view of the structure of the second drive unit of this embodiment. In the structure of the second drive unit, gap 71 is filled with grease 75. Grease 75 is arranged in gap 71 to seal the passage for foreign matter to enter. This structure prevents foreign matter from reaching oil seal 35, and more reliably suppresses deterioration or damage to oil seal 35.

[0080] exist Figure 14 In the example shown, the entire gap 71 is filled with grease 75. Furthermore, the entire passage 69 formed within the labyrinth member 41 is also filled with grease 75, but this is not limiting. Grease 75 only needs to be filled in at least a portion of the gap 71 so as to block the passage from the opening 71a to the oil seal 35.

[0081] Grease 75 is preferably water-resistant, meaning it is difficult for liquids such as cleaning fluid to flow. Alternatively, grease 75 is preferably resistant to corrosion by foreign matter. However, if the type of cleaning fluid is changed, grease 75 may be washed away. Even in this case, grease 75 that is water-resistant to cleaning fluid can be easily filled into gap 71. Grease 75 can be filled or its type changed before oil seal 35 deteriorates or is damaged. The remaining structure, functions, and effects are similar to those of the first drive unit and are not repeated here.

[0082] Figure 15 2 is a schematic cross-sectional view showing the structure of the third driving portion of this embodiment. Figure 16 An enlarged schematic cross-sectional view of a portion where an oil seal and a labyrinth member are disposed is shown in FIG. Figure 15 and Figure 16 In the structure of the third driving portion, a gas supply pipe 51 is provided that communicates with the gap 71. The gas supply pipe 51 penetrates the housing 12a and is formed so as to supply air as gas into the gap 71.

[0083] A check valve 52 is connected to the gas supply pipe 51. The check valve 52 of this embodiment includes a closing plate 52a biased by a spring 52b. The closing plate 52a opens when the pressure inside the housing 12a of the lower arm 12 exceeds the pressure in the gap 71.

[0084] The robot 1 of this embodiment includes an air supply device for supplying air into the interiors of the housings 12a and 13a. Pressurized air is supplied to the interiors of the housings 12a and 13a to protect the equipment within the housings 12a and 13a. When the robot 1 is driven, the air pressure inside the housings 12a and 13a becomes higher than atmospheric pressure. The closing plate 52a of the check valve 52 opens, forming an air flow path.

[0085] As indicated by arrow 93, air flows from the interior of housing 12a toward gap 71. Within gap 71, as indicated by arrow 94, air flows toward labyrinth 41. Then, as indicated by arrow 95, air is released from passage 69 toward the exterior of labyrinth 41. By supplying air to gap 71 in this manner, air is released from passage 69. This effectively prevents foreign matter from entering passage 69, and more reliably prevents foreign matter from reaching oil seal 35.

[0086] The device for supplying air to the gap portion can adopt any structure. For example, the pipe connected to the pump can be connected to the gas supply pipe. The other structures, functions and effects are the same as those of the first drive unit, so they are not repeated here.

[0087] Figure 17 , an enlarged schematic cross-sectional view of the structure of the fourth drive unit of this embodiment is shown. In the structure of the fourth drive unit, a third labyrinth member 54 is disposed on the outer peripheral surface of the joint portion 18a. The third labyrinth member 54 includes a first annular member 55 fixed to the housing 13a and a second annular member 56 fixed to the housing 12a. Driven by the joint portion 18a, the first annular member 55 and the second annular member 56 slide relative to each other. The first annular member 55 functions as a first sliding member fixed to the first structural portion 9. The second annular member 56 functions as a second sliding member fixed to the second structural portion 10.

[0088] In this embodiment, the first annular member 55 and the second annular member 56 are formed of a material that wears away when sliding against each other. In this embodiment, the annular members 55 and 56 are formed of polytetrafluoroethylene (PTFE) which is a fluororesin.

[0089] Figure 17 , the state before the joint portion 18a of the robot 1 starts to be used is shown. The contact surface 55a of the annular member 55 and the contact surface 56a of the annular member 56 are in contact with each other. When the joint portion 18a is driven, the second structural portion 10 rotates relative to the first structural portion 9. Therefore, the annular member 56 fixed to the housing 12a rotates relative to the annular member 55 fixed to the housing 13a. The contact surface 56a slides relative to the contact surface 55a, and as a result, the annular member 55 and the annular member 56 wear. As a result, a gap as shown in FIG. 5 is formed between the annular member 55 and the annular member 56. Figure 3 A passage with a small cross-sectional area such as the passage 69. In this way, the labyrinth member can also be formed by a member that is worn by using the driving portion.

[0090] exist Figure 17In the example shown, a member that wears by sliding is arranged on the surface of each housing 12a, 13a, but the present invention is not limited to this embodiment. A member that wears by sliding can be arranged in a portion forming a passage of the labyrinth member. For example, referring to Figure 3 In the first labyrinth member 41 of the present embodiment, a member that wears due to sliding may be arranged on the opposing surfaces of the first annular member 42 and the second annular member 43 .

[0091] In addition, Figure 17 In the illustrated example, both annular members 55 and 56 are formed from materials that wear due to sliding, but this is not limiting. Alternatively, either the first or second sliding member may be formed from a material that wears due to sliding. The remaining structure, functions, and effects are similar to those of the first drive unit, and therefore will not be repeated here.

[0092] Figure 18 FIG shows an enlarged schematic cross-sectional view of the structure of the fifth drive unit of this embodiment. In the structure of the fifth drive unit, the structure of the labyrinth member is different from that of the first drive unit. Figure 3 In the structure of the first driving portion, the first labyrinth member 41 is composed of a plurality of opposing members facing each other. Figure 18 In the structure of the fifth drive unit, a fourth labyrinth member 58, consisting of a single component, is fixed to the housing 13a. The labyrinth member 58 is formed into an annular shape so as to cover the opening 71a. The labyrinth member 58 is formed so as to face the outer peripheral surface of the housing 12a. The area sandwiched between the surface of the labyrinth member 58 and the surface of the housing 12a forms a passage 69.

[0093] In this way, the labyrinth component can also be formed by one component. Figure 18 In the example shown, the labyrinth member 58 is fixed to the first structure 9, but the present invention is not limited to this and may be fixed to the second structure 10. The other structures, functions, and effects are the same as those of the first drive unit and will not be described again here.

[0094] Figure 19 A schematic partial cross-sectional view showing the structure of the sixth driving unit of this embodiment is shown in FIG. Figure 20 FIG shows an enlarged schematic cross-sectional view of a portion of the structure of the sixth drive unit where a labyrinth member is disposed. Figure 19 and Figure 20 In the structure of the sixth drive unit, the outer peripheral surface of the speed reducer 31 is exposed without being covered by the housing. The gap 71 is formed by the area surrounded by the speed reducer 31 and the housing 12a. Part of the labyrinth is fixed to the outer peripheral surface of the speed reducer 31.

[0095] In the example here, the first annular member 42 of the first labyrinth member 41 is arranged on the outer peripheral surface of the speed reducer 31. The first annular member 42 is fixed to the outer peripheral surface of the fixing portion 31a. The second annular member 43 is fixed to the housing 12a. In this way, it is also possible that at least a portion of the labyrinth member 41 is fixed to the surface of the speed reducer 31. The passage 69 of the labyrinth member 41 is composed of an area sandwiched by the first annular member 42 and the second annular member 43, which is the same as the structure of the first drive unit. The other structures, functions, and effects are the same as those of the structure of the first drive unit, and therefore will not be repeated here.

[0096] In the above-described drive unit structure, the joint 18a that rotates the lower arm 12 relative to the rotating base 13 is described as an example, but the present invention is not limited to this embodiment and can be applied to any joint structure of a robot.

[0097] In this embodiment, a robot is used as an example of a device equipped with a drive unit, but the present invention is not limited to this embodiment. Any device equipped with a drive unit that causes a first structural unit and a second structural unit opposing the first structural unit to rotate relative to each other can be used. In particular, the drive unit structure of this embodiment is suitable for devices where foreign matter may enter the gap between the first and second structural units. For example, the drive unit structure of this embodiment can be applied to the drive unit of a machine tool or the drive unit of a conveyor device.

[0098] The above embodiments can be combined as appropriate. In the above drawings, the same or equivalent parts are marked with the same reference numerals. In addition, the above embodiments are illustrative and are not intended to limit the invention. In addition, the embodiments include changes to the embodiments shown in the claims.

[0099] Description of Reference Numerals

[0100] 1. Robot; 9. First structural unit; 10. Second structural unit; 12. Lower arm; 12a. Housing; 13. Rotating base; 13a. Housing; 18a, 18b, 18c. Joint; 19. Upper member; 20. Lower member; 21. Motor; 31. Speed ​​reducer; 31a. Fixed unit; 31b. Movable unit; 35. Oil seal; 37. Sealing member; 41. Labyrinth member; 42, 43, 46, 47. 7. Annular member; 42a, 43a, 46a, 47a, dividing member; 44, double-sided tape; 48, bolt; 49, nut; 51, gas supply pipe; 54, labyrinth member; 55, 56, annular member; 55a, 56a, contact surface; 58, labyrinth member; 59, labyrinth member; 60, 61, linear member; 69, passage; 71, 72, gap portion; 71a, opening portion; 75, grease.

Claims

1. A structure of a driving portion, wherein the driving portion causes a first structure portion and a second structure portion facing the first structure portion to rotate relative to each other, wherein: The structure of the drive unit has: a sealing member disposed in a gap portion serving as a space between the first structural portion and the second structural portion; and a passage constituting member disposed on outer surfaces of the first structural portion and the second structural portion, The sealing member is fixed to the first structural portion and is in contact with the second structural portion. The gap portion has an opening portion communicating with the outside of the driving portion, The passage forming member has a shape forming a passage communicating with the opening. The passage constituting member is formed so as to be attachable to the outer surface of the first structural portion and the outer surface of the second structural portion, and is formed so as to be detachable from the first structural portion and the second structural portion in such a manner that the structure of the driving portion can be operated with the passage constituting member removed. The passage constituting member includes: a first opposing member fixed to the first structural portion; and a second opposing member fixed to the second structural portion and arranged to face the first opposing member. The passage is formed by a region sandwiched between the first opposing member and the second opposing member. The first relative member is formed so as to be able to be installed on the outer surface of the first structural part and to be removed in a manner that allows the structure of the driving part to operate after the first relative member is removed. The second relative member is formed so as to be able to be installed on the outer surface of the second structural part and to be removed in a manner that allows the structure of the driving part to operate after the second relative member is removed.

2. The structure of the driving portion according to claim 1, wherein: The first opposing member includes a first sliding member, The second opposing member includes a second sliding member, At least one of the first sliding member and the second sliding member is formed of a material that wears away when the first sliding member and the second sliding member slide against each other. Before the drive unit starts to be used, the first sliding member and the second sliding member are in contact with each other. When the drive unit starts to be used, at least one of the first sliding member and the second sliding member is worn to form the passage.

3. The structure of the driving portion according to claim 1 or 2, wherein: The drive unit is constructed with grease, which is water-resistant. The grease is filled in the gap.

4. The structure of the driving portion according to claim 1 or 2, wherein: The driving portion has a gas supply pipe that is connected to the gap portion and supplies gas into the gap portion. The gas supplied from the gas supply pipe is released to the outside of the passage constituent member through the gap and the passage.

5. The structure of the driving portion according to claim 1 or 2, wherein: The passage is formed to extend in a direction intersecting with a direction in which the gap extends at the opening.

6. The structure of the driving portion according to claim 1 or 2, wherein: The first opposing member is fixed to the first structural portion by a fastening member or a double-sided tape. The second opposing member is fixed to the second structural portion by a fastening member or a double-sided tape.

7. A robot, wherein: The robot has: a first structural member comprising a first shell; a second structural member comprising a second shell; a joint portion that rotates the second structural member relative to the first structural member; as well as a passage constituting member disposed on the outer surface of the joint portion, The joint portion includes: a speed reducer connected to the motor; and a sealing member for suppressing outflow of lubricating oil inside the speed reducer. The shell of the joint portion is composed of the first shell and the second shell. A gap portion is formed inside the joint portion, and the gap portion has an opening portion communicating with the outside of the joint portion. The sealing member is disposed in the gap, fixed to the first housing or a member fixed to the first housing, and in contact with the second housing or a member fixed to the second housing. The passage forming member has a shape forming a passage communicating with the opening. The passage forming member is formed so as to be attachable to the outer surface of the joint portion and is formed so as to be detachable from the outer surface of the joint portion in a manner such that the robot can operate with the passage forming member removed. The first housing and the second housing are formed so as to cover the outer peripheral surface of the speed reducer. The passage constituting member includes: a first annular member fixed to the outer peripheral surface of the first housing; and a second annular member fixed to the second housing. The passage is formed by a region sandwiched between the first annular member and the second annular member. The first annular member is formed so as to be installable on the outer peripheral surface of the first shell and to be removeable in a manner that allows the robot to operate with the first annular member removed. The second annular member is formed so as to be installable on the outer peripheral surface of the second shell and to be removeable in a manner that allows the robot to operate with the second annular member removed.

8. A robot, wherein: The robot has: a first structural member comprising a first shell; a second structural member comprising a second shell; a joint portion that rotates the second structural member relative to the first structural member; as well as a passage constituting member disposed on the outer surface of the joint portion, The joint portion includes: a speed reducer connected to the motor; and a sealing member for suppressing outflow of lubricating oil inside the speed reducer. The shell of the joint portion is composed of the first shell and the second shell. A gap portion is formed inside the joint portion, and the gap portion has an opening portion communicating with the outside of the joint portion. The sealing member is disposed in the gap, fixed to the first housing or a member fixed to the first housing, and in contact with the second housing or a member fixed to the second housing. The passage forming member has a shape forming a passage communicating with the opening. The passage forming member is formed so as to be attachable to the outer surface of the joint portion and is formed so as to be detachable from the outer surface of the joint portion in a manner such that the robot can operate with the passage forming member removed. The reducer is formed with its outer peripheral surface exposed, The passage constituting member includes: a first annular member fixed to the outer peripheral surface of the speed reducer; and a second annular member fixed to the second housing. The passage is formed by a region sandwiched between the first annular member and the second annular member. The first annular member is formed so as to be installable on the outer peripheral surface of the reducer and to be removeable in a manner that allows the robot to operate with the first annular member removed. The second annular member is formed so as to be installable on the outer peripheral surface of the second shell and to be removeable in a manner that allows the robot to operate with the second annular member removed.

9. The robot according to claim 7 or 8, wherein: The first annular member and the second annular member are formed into an annular shape. Each annular member includes a plurality of divided members whose side surfaces are formed into arc shapes, and the plurality of divided members are fixed to each other by fastening members.

10. The robot according to claim 7 or 8, wherein: The first annular member and the second annular member are formed into an annular shape. Each annular member includes a plurality of segmented members having arc-shaped side surfaces, and the segmented members are fixed to the outer peripheral surface of the first housing, the outer peripheral surface of the second housing, or the outer peripheral surface of the speed reducer using double-sided tape.

11. The robot according to claim 7 or 8, wherein: The first annular member and the second annular member are formed into an annular shape. Each annular member is configured as a deformable belt-shaped member fixed to the outer peripheral surface of the first housing, the outer peripheral surface of the second housing, or the outer peripheral surface of the speed reducer.

Images