Reducer and industrial robot

Abstract

Embodiments of the present disclosure relate to a speed reducer and an industrial robot. The speed reducer comprises: a housing; a low-speed output portion coupled to the housing; a high-speed input portion, which is coupled to the housing and comprises an input shaft, wherein an internal space surrounded by the housing, the low-speed output portion and the high-speed input portion is filled with a lubricant, and the input shaft comprises a channel connecting the internal space and the external environment; and a blocking film, which is configured to block the channel and is air-permeable but impermeable to lubricants. According to various embodiments of the present disclosure, during the operation of the speed reducer, due to the centrifugal force generated by the high-speed rotation of the input shaft, the lubricant adhering to the film will fly out of the film. In this way, the influence of the lubricant on the ventilation capacity of the membrane can be reduced, so that the internal pressure can be released in time.

Description

Technical Field

[0001] The disclosed embodiments generally relate to the field of speed reducers, and more particularly to speed reducers and industrial robots. Background Art

[0002] A speed reducer is a machine that reduces the speed of the driving power (torque) input to the input shaft and transmits the power to the target machine at the reduced speed. Speed ​​reducers are widely used to drive a variety of equipment or machines such as industrial robots, power tools, and automobiles.

[0003] A speed reducer generally includes a housing, a high-speed input portion, and a low-speed output portion. The high-speed input portion and the low-speed output portion are coupled to the housing and together with the housing form a closed internal space. A lubricant is provided in the internal space for the purpose of reducing friction and cooling. During the operation of the speed reducer, internal pressure may accumulate in the internal space due to various reasons, such as temperature increase, lubricant evaporation, and the pumping effect of the seal. The accumulation of internal pressure may cause the lubricant to leak from the speed reducer. For example, in the case where the speed reducer is used to drive the joints of an industrial robot, the leakage of the lubricant may reduce the lubrication performance of the speed reducer and contaminate the robot and the work object.

[0004] In order to prevent such internal pressure accumulation, for example, an air release hole may be provided on the reducer, and a membrane made of a special material such as polytetrafluoroethylene (PTFE) may be provided to block the air release hole. The membrane is permeable to air but impermeable to lubricant, thereby releasing the internal pressure of the reducer and keeping the lubricant in the internal space. However, if the lubricant reaches and adheres to the membrane, the ventilation capacity of the membrane may be adversely affected, thereby blocking the release path of the internal pressure.

[0005] For fixed orientation applications such as automotive transmissions, the vent valve can be placed on the topmost side of the reducer housing to minimize the impact of lubricant on the membrane. However, for equipment or machines that change orientation during operation, such as industrial robotic applications, it is difficult (sometimes impossible) to find such a fixed location for the vent valve. For example, the reducer of a 6-axis robot can rotate in any direction, so the lubricant in the reducer will definitely reach the membrane, resulting in a reduction in the membrane's ventilation capacity.

[0006] US Patent No. 8171822B2 discloses a material that is oil-repellent, breathable and oil-impermeable. However, since the properties of lubricants may vary, it is difficult to find a specific membrane material that is oil-repellent to various lubricants as a universal solution. In addition, in US Patent No. 8171822B2, if the membrane is impregnated with lubricant in a certain orientation, the pressure release hole will be blocked.

[0007] Therefore, a solution is needed to prevent lubricant leakage and internal pressure accumulation of the reducer. Summary of the invention

[0008] In view of the above-mentioned problems, exemplary embodiments of the present disclosure provide a speed reducer capable of preventing both leakage of lubricant and accumulation of internal pressure.

[0009] In a first aspect of the present disclosure, an exemplary embodiment of the present disclosure provides a speed reducer. The speed reducer comprises: a housing; a low-speed output portion coupled to the housing; a high-speed input portion coupled to the housing and comprising an input shaft, wherein an internal space surrounded by the housing, the low-speed output portion and the high-speed input portion is filled with a lubricant, and the input shaft comprises a channel connecting the internal space and an external environment; and a blocking film arranged on the input shaft, the blocking film being used to block the channel and being air-permeable but impermeable to the lubricant.

[0010] In some embodiments, the input shaft is a hollow shaft, and wherein the channel includes: a central through hole, which extends from one end of the input shaft to the other end along the axial direction of the input shaft and is fluidly connected to the external environment; and a first through hole, which extends from the outer wall to the inner wall of the input shaft and connects the internal space and the central through hole.

[0011] In some embodiments, the first through hole extends from an outer wall to an inner wall of the input shaft along a radial direction perpendicular to the axial direction of the input shaft.

[0012] In some embodiments, the first through hole includes a stepped portion, and the barrier film is disposed on the stepped portion.

[0013] In some embodiments, the reducer further includes a fixing device configured to fix the barrier film on the step portion of the first through hole.

[0014] In some embodiments, the input shaft is a solid shaft, and wherein the passage includes: a side hole extending from an end of the input shaft to a position between the two ends of the input shaft and connected to the external environment fluid; and a second through hole extending from an outer wall of the input shaft to the side hole and connecting the internal space and the side hole.

[0015] In some embodiments, the side hole extends in an axial direction of the input shaft.

[0016] In some embodiments, the second through hole extends from the outer wall of the input shaft to the side hole in a radial direction of the input shaft.

[0017] In some embodiments, the second through hole includes a stepped portion, and the barrier film is disposed on the stepped portion.

[0018] In some embodiments, the reducer further includes a fixing device configured to fix the barrier film on the step portion of the second through hole.

[0019] In some embodiments, the reducer is used to drive the joints of an industrial robot.

[0020] In a second aspect of the present disclosure, an example embodiment of the present disclosure provides an industrial robot including the speed reducer according to the first aspect of the present disclosure.

[0021] According to various embodiments of the present disclosure, a channel and a membrane for blocking the channel are arranged on the input shaft to release the internal pressure of the reducer and keep the lubricant in the internal space. With this arrangement, during the operation of the reducer, due to the centrifugal force generated by the high-speed rotation of the input shaft, the lubricant adhering to the membrane will fly out of the membrane. In this way, the influence of the lubricant on the ventilation capacity of the membrane can be reduced, so that the internal pressure can be released in time.

[0022] In addition, since the position and orientation of the film change over time, it is possible to prevent the film from being immersed in the lubricant. Therefore, the speed reducer is suitable for various devices or machines that change position and orientation during operation, such as industrial robots.

[0023] In addition, the material of the film does not need to be oil-repellent because the lubricant adhering to the film is removed mechanically rather than chemically. Therefore, it is easy to find a suitable material for the film. The disclosed embodiments provide a universal solution for various lubricants with different chemical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other purposes, features and advantages of the example embodiments disclosed herein will become more easily understood through the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, several example embodiments disclosed herein are shown in an exemplary and non-limiting manner, in which:

[0025] Figure 1 A perspective view showing a speed reducer according to one embodiment of the present disclosure;

[0026] Figure 2 yes Figure 1 A cross-sectional view of the reducer shown;

[0027] Figure 3 A perspective view showing a speed reducer according to another embodiment of the present disclosure; and

[0028] Figure 4 yes Figure 3 Cross-section of the reducer shown.

[0029] Throughout the drawings, the same or similar reference numbers are used to refer to the same or similar elements. DETAILED DESCRIPTION

[0030] The principles of the present disclosure will now be described with reference to several example embodiments shown in the accompanying drawings. Although example embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the purpose of describing these embodiments is only to enable those skilled in the art to better understand and further implement the present disclosure, and is not intended to limit the scope of the present disclosure in any way.

[0031] The terms "including" or "comprising" and their variations should be understood as open terms, meaning "including but not limited to". The term "or" should be interpreted as "and / or", unless the context clearly indicates otherwise. The term "based on" should be understood as "based at least in part on". The term "operable as" represents a function, action, movement or state that can be achieved by an operation caused by a user or an external mechanism. The terms "one embodiment" and "embodiment" should be understood as "at least one embodiment". The term "another embodiment" should be understood as "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other definitions (explicit and implicit) may be included below. Unless the context clearly indicates otherwise, the definitions of terms are consistent throughout the specification.

[0032] Unless otherwise specified or limited, the terms "mounted," "connected," "supported," and "coupled," and variations thereof, are used broadly and include both direct and indirect mountings, connections, supports, and couplings. Additionally, "connected" and "coupled" are not limited to physical or mechanical connections or couplings. In the following description, like reference numerals and numbers are used to describe the same, similar, or corresponding parts in the drawings. Other definitions (explicit and implicit) may be included below.

[0033] As described above, if the lubricant reaches and adheres to the membrane to release the internal pressure of the reducer, the ventilation capacity of the membrane may be adversely affected, thereby blocking the release path of the internal pressure. According to an embodiment of the present disclosure, in order to prevent lubricant leakage and internal pressure accumulation, a channel and a membrane for blocking the channel are provided on the input shaft of the reducer to release the internal pressure of the reducer and avoid the lubricant from adhering to the membrane. As will be described in detail in the following paragraphs, the above idea can be implemented in various ways.

[0034] The following will be combined Figures 1 to 4 The principle of the present disclosure is described in detail. Figure 1 and Figure 2 , Figure 1 A perspective view showing a reducer 100 according to an embodiment of the present disclosure, Figure 2 yes Figure 1 FIG. 1 is a cross-sectional view of the reducer 100. Figure 1 and Figure 2As shown, the speed reducer 100 generally includes a housing 2, a low-speed output part 3 and a high-speed input part 4. The high-speed input part 4 and the low-speed output part 3 are coupled to the housing 2 and together with the housing 2 form a closed internal space 5. A lubricant (not shown) is provided in the internal space 5 for the purpose of reducing friction. The high-speed input part 4 includes an input shaft 41 for receiving a driving power (torque) input from a driver such as a motor. The low-speed output part 3 can transmit power to a target machine at a reduced speed.

[0035] During the operation of the reducer 100, internal pressure may accumulate in the internal space 5 due to various reasons, such as temperature increase, lubricant evaporation, and the pumping effect of the seal. In order to release the internal pressure in the internal space 5 of the reducer 100, a channel 42 is provided in the input shaft 41. The channel 42 communicates the internal space 5 with the external environment. The reducer 100 further includes a barrier film 6, which is arranged on the input shaft 41 to block the channel 42. The barrier film 6 is permeable to air but impermeable to lubricant, thereby releasing the internal pressure of the reducer 100 and keeping the lubricant in the internal space 5.

[0036] Since the channel 42 and the blocking film 6 for blocking the channel 42 are arranged on the input shaft 41, when the input shaft 41 rotates, the blocking film 6 can rotate synchronously with the input shaft 41. The rotation of the blocking film 6 will subject the lubricant (if any) adhering to the blocking film 6 to centrifugal force. Under the action of the centrifugal force, during the high-speed rotation of the input shaft 41, the lubricant adhering to the blocking film 6 will fly out of the blocking film 6. In this way, the influence of the lubricant on the ventilation capacity of the blocking film 6 can be reduced, so that the internal pressure of the reducer 100 can be released in time.

[0037] In some embodiments, Figure 1 and Figure 2 As shown, the input shaft 41 is a hollow shaft. The hollow input shaft 41 includes a central through hole 421, which extends from one end of the input shaft 41 to the other end along the axial direction X of the input shaft 41. The central through hole 421 is in fluid communication with the external environment.

[0038] In one embodiment, the input shaft 41 further includes a first through hole 422 extending from the outer wall 411 to the inner wall 412 of the input shaft 41. The first through hole 422 communicates the inner space 5 with the central through hole 421. With this arrangement, the first through hole 422 can form a channel 42 together with the central through hole 421, so that the inner space 5 is in fluid communication with the external environment. The barrier film 6 can be arranged on the input shaft 41 to cover the first through hole 422.

[0039] In another embodiment, in addition to the first through hole 422, the input shaft 41 may further include one or more additional through holes connecting the internal space 5 and the central through hole 421. Similarly, the additional through holes are covered by corresponding barrier films. Providing additional through holes on the input shaft 41 can further improve the internal pressure release performance in the reducer 100.

[0040] In some embodiments, Figure 1 and Figure 2 As shown, the first through hole 422 extends from the outer wall 411 of the input shaft 41 to the inner wall 412 along the radial direction R of the input shaft 41 that is perpendicular to the axial direction X. In some embodiments, the first through hole 422 may extend from the outer wall 411 of the input shaft 41 to the inner wall 412 along a direction inclined relative to the radial direction R of the input shaft 41. In other embodiments, the first through hole 422 may be curved or even include a plurality of sub-portions that are connected to each other, as long as the sub-portions are connected to the inner space 5 and the central through hole 421.

[0041] In some embodiments, Figure 1 and Figure 2 As shown, the first through hole 422 includes a step portion 420. The barrier film 6 is arranged on the step portion 420. In one embodiment, the reducer 100 may further include a fixing device 7, which is suitable for fixing the barrier film 6 on the step portion 420 of the first through hole 422. For example, the fixing device 7 may be formed as an annular fixing device. The annular fixing device 7 may be interference-fitted with the first through hole 422. By pressing the annular fixing device 7 into the first through hole 422, the barrier film 6 can be reliably fixed on the step portion 420.

[0042] In some embodiments, the blocking film 6 may be adhered to the input shaft 41 by an adhesive to cover the first through hole 422. In other embodiments, the blocking film 6 may be fixed to the input shaft 41 in other ways. The scope of the present disclosure is not intended to be limited in this respect.

[0043] Figure 3 A perspective view showing a reducer 100 according to another embodiment of the present disclosure is shown. Figure 4 yes Figure 3 The cross-sectional view of the reducer 100 is shown. Figure 1 and Figure 2 The reducer 100 shown is similar, Figure 3 and Figure 4 The illustrated speed reducer 100 also includes a housing 2, a low-speed output portion 3, and a high-speed input portion 4. The high-speed input portion 4 and the low-speed output portion 3 are coupled to the housing 2 and together with the housing 2 form a closed internal space 5. Lubricant is provided in the internal space 5 for the purpose of reducing friction.

[0044] During the operation of the reducer 100, internal pressure may accumulate in the internal space 5 due to various reasons. In order to release the internal pressure in the internal space 5 of the reducer 100, a channel 42 is provided in the input shaft 41. The channel 42 communicates the internal space 5 with the external environment. The reducer 100 further includes a barrier film 6, which is arranged on the input shaft 41 to block the channel 42. The barrier film 6 is permeable to air but impermeable to lubricant, thereby releasing the internal pressure of the reducer 100 and keeping the lubricant in the internal space 5.

[0045] In some embodiments, Figure 3 and Figure 4 As shown, the input shaft 41 is a solid shaft. The solid input shaft 41 includes a side hole 423, which extends from the end of the input shaft 41 to a position between the two ends of the input shaft 41. The side hole 423 is in fluid communication with the external environment. The solid input shaft 41 also includes a second through hole 424, which extends from the outer wall 411 of the input shaft 41 to the side hole 423. The second through hole 424 communicates with the internal space 5 and the side hole 423. With this arrangement, the second through hole 424 can form a channel 42 together with the side hole 423, so that the internal space 5 is in fluid communication with the external environment. The barrier film 6 can be arranged on the input shaft 41 to cover the second through hole 424.

[0046] In some embodiments, Figure 3 and Figure 4 As shown, the side hole 423 extends along the axial direction X of the input shaft 41. In some embodiments, the side hole 423 may extend along a direction inclined relative to the axial direction X of the input shaft 41. In other embodiments, the side hole 423 may be curved or even include a plurality of sub-portions that are connected to each other, as long as the sub-portions connect the second through hole 424 with the external environment.

[0047] In some embodiments, Figure 3 and Figure 4 As shown, the second through hole 424 extends from the outer wall 411 of the input shaft 41 to the side hole 423 along the radial direction R of the input shaft 41. In some embodiments, the second through hole 424 may extend from the outer wall 411 of the input shaft 41 to the side hole 423 along a direction inclined relative to the radial direction R of the input shaft 41. In other embodiments, the second through hole 424 may be curved or even include a plurality of sub-portions communicating with each other, as long as the sub-portions communicate with the internal space 5 and the side hole 423.

[0048] Similar to the first through hole 422, Figure 3 and Figure 4As shown, the second through hole 424 may include a step portion 420. The barrier film 6 is arranged on the step portion 420. In one embodiment, the reducer 100 may further include a fixing device 7, which is suitable for fixing the barrier film 6 on the step portion 420 of the second through hole 424. For example, the fixing device 7 may be formed as an annular fixing device. The annular fixing device 7 may be interference-fitted with the second through hole 424. By pressing the annular fixing device 7 into the second through hole 424, the barrier film 6 can be reliably fixed on the step portion 420.

[0049] In some embodiments, the blocking film 6 may be adhered to the input shaft 41 by an adhesive to cover the second through hole 424. In other embodiments, the blocking film 6 may be fixed to the input shaft 41 in other ways. The scope of the present disclosure is not intended to be limited in this respect.

[0050] The reducer 100 may be various types of reducers, such as a harmonic reducer, a gear reducer, etc. In addition, the reducer 100 may also be used in various devices or machines, such as industrial robots, power tools, automobiles, etc. For example, the reducer 100 may be used to drive the joints of an industrial robot.

[0051] According to various embodiments of the present disclosure, the channel 42 and the barrier film 6 are provided on the input shaft 41 to release the internal pressure of the reducer 100 and to keep the lubricant in the internal space 5. With this arrangement, during the operation of the reducer 100, due to the centrifugal force generated by the high-speed rotation of the input shaft 41, the lubricant adhering to the barrier film 6 will fly out of the barrier film 6. In this way, the influence of the lubricant on the ventilation capacity of the barrier film 6 can be reduced, so that the internal pressure can be released in time.

[0052] Furthermore, since the position and orientation of the barrier film 6 change over time, the barrier film 6 can be prevented from being immersed in the lubricant. Therefore, the speed reducer 100 is suitable for various devices or machines that change position and orientation during operation, such as an industrial robot.

[0053] In addition, the material of the barrier film 6 does not need to be oil-repellent, because the lubricant adhering to the barrier film 6 is removed mechanically rather than chemically. Therefore, it is easy to find a suitable material for the barrier film 6. In the disclosed embodiment, the barrier film 6 can be various known materials, such as polytetrafluoroethylene (PTFE), or other available materials developed in the future. In fact, the disclosed embodiment provides a universal solution for various lubricants with different chemical properties.

[0054] Although multiple inventive embodiments are described and illustrated herein, a person of ordinary skill in the art can easily foresee various other devices and / or structures for performing the functions described herein and / or obtaining the results and / or one or more advantages described herein, and each such variation and / or modification is considered to fall within the scope of the inventive embodiments described herein. More generally, it will be readily understood by those skilled in the art that all parameters, dimensions, materials, and configurations described herein are exemplary, and the actual parameters, dimensions, materials, and / or configurations depend on one or more specific applications to which the teachings of this invention are applied. Those skilled in the art will recognize, or be able to ascertain using only routine experimental methods, many equivalents of the specific inventive embodiments described herein. Therefore, it should be understood that the above embodiments are presented only in an exemplary manner, and that, within the scope of the appended claims and their equivalents, the inventive embodiments may be practiced in other ways than those specifically described and claimed herein. The inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, toolbox, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits and / or methods (if such features, systems, articles, materials, kits and / or methods are not mutually inconsistent) is included within the inventive scope of the present disclosure.

Claims

1. A reducer (100), comprising: Housing (2); A low-speed output portion (3) coupled to the housing (2); a high-speed input part (4), the high-speed input part (4) being coupled to the housing (2) and comprising an input shaft (41), wherein an internal space (5) surrounded by the housing (2), the low-speed output part (3) and the high-speed input part (4) is filled with lubricant, and the input shaft (41) comprises a channel (42) connecting the internal space (5) and the external environment; as well as A blocking film (6) is arranged on the input shaft (41) to block the passage (42) and is permeable to air but impermeable to lubricant.

2. The speed reducer (100) according to claim 1, wherein the input shaft (41) is a hollow shaft, and wherein the channel (42) comprises: a central through hole (421), the central through hole (421) extending from one end of the input shaft (41) to the other end along the axial direction (X) of the input shaft (41) and being in fluid communication with the external environment; and A first through hole (422), the first through hole (422) extends from the outer wall (411) to the inner wall (412) of the input shaft (41) and connects the internal space (5) and the central through hole (421).

3. The reducer (100) according to claim 2, wherein the first through hole (422) extends from the outer wall (411) of the input shaft (41) to the inner wall (412) along a radial direction (R) of the input shaft (41) perpendicular to the axial direction (X).

4. The reducer (100) according to claim 3, wherein the first through hole (422) includes a stepped portion (420), and the barrier film (6) is arranged on the stepped portion (420).

5. The reducer (100) according to claim 4, further comprising a fixing device (7), wherein the fixing device (7) is configured to fix the barrier film (6) on the step portion (420) of the first through hole (422).

6. The speed reducer (100) according to claim 1, wherein the input shaft (41) is a solid shaft, and wherein the channel (42) comprises: a side hole (423) extending from an end of the input shaft (41) to a position between the two ends of the input shaft (41) and in fluid communication with the external environment; and A second through hole (424), the second through hole (424) extends from the outer wall (411) of the input shaft (41) to the side hole (423) and communicates the internal space (5) with the side hole (423).

7. The speed reducer (100) according to claim 6, wherein the side hole (423) extends along the axial direction (X) of the input shaft (41).

8. The reducer (100) according to claim 6, wherein the second through hole (424) extends from the outer wall (411) of the input shaft (41) to the side hole (423) along the radial direction (R) of the input shaft (41).

9. The reducer (100) according to claim 8, wherein the second through hole (424) includes a stepped portion (420), and the blocking film (6) is arranged on the stepped portion (420).

10. The reducer (100) according to claim 9, further comprising a fixing device (7), wherein the fixing device (7) is configured to fix the barrier film (6) on the step portion (420) of the second through hole (424).

11. The reducer (100) according to claim 1, wherein the reducer (100) is used to drive a joint of an industrial robot.

12. An industrial robot comprising the reducer (100) according to any one of claims 1 to 11.

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