RV speed reducer applied to industrial robot

Abstract

This invention relates to the field of industrial robot reducer technology, specifically providing an RV reducer for industrial robots. The reducer includes a housing, within which an input shaft and a rotating frame are rotatably mounted. Three rotating shafts are circumferentially and uniformly connected to the rotating frame. These three rotating shafts are connected to the input shaft via planetary gears. Each of the three rotating shafts has a first channel and a second channel axially formed inside. The first and second channels are respectively located close to the axes of two eccentric wheels, thereby reducing the mass of the rotating shaft in the eccentric wheel axis region, minimizing the eccentric load generated during eccentric wheel rotation, and reducing the eccentric load force of the cycloidal wheel on the eccentric wheel. This avoids the increased clearance between the rotating groove and the eccentric wheel and component damage caused by eccentric load in traditional RV reducers, extends the service life of the rotating shaft, eccentric wheel, and cycloidal wheel, and simultaneously reduces the vibration amplitude during operation, ensuring the smoothness of the joint transmission of the industrial robot.

Description

Technical Field

[0001] This invention relates to the field of industrial robot reducer technology, and in particular to an RV reducer for use in industrial robots. Background Technology

[0002] RV reducers are the core transmission components of industrial robot joints. Their core advantages are high transmission accuracy, high rigidity, and large load-bearing capacity. They are widely used in robot joints, CNC machine tools, automated production lines, and other scenarios with extremely high requirements for precision and stability.

[0003] For example, Chinese patent CN110185748B discloses an integrated robot joint structure. This solution includes an output end body, a pin tooth housing of an RV reducer, a fixed end body, an integrated motor, an output disc frame of the RV reducer, an eccentric shaft, planetary gears, angular contact ball bearings, and cycloidal wheels. The integrated motor and the pin tooth housing of the RV reducer are combined into an integrated unit. The pin tooth housing of the RV reducer in the integrated unit is fixedly connected to the fixed end body. The output disc frame of the RV reducer is connected to the output end body. The eccentric shaft includes a cam, a concentric circle of the eccentric shaft, a tapered roller bearing, and a needle roller retainer. This solution uses the above structure to enable two cycloidal wheels to achieve staggered circumferential oscillation through different cams on the eccentric wheel, thereby driving the pin tooth housing of the RV reducer to rotate and achieve the second stage of reduction.

[0004] However, in the above scheme, the two cams on the eccentric shaft are eccentrically set and symmetrically, and the eccentric directions of the two cams are opposite. Therefore, when the cycloidal wheel is working, the cycloidal wheel will generate an eccentric load on the cam. After long-term operation, it is easy to cause the gap to increase or be damaged. Even when rotating, the existence of torque will cause the device to vibrate. Summary of the Invention

[0005] Therefore, it is necessary to address the problem of eccentric load between the internal eccentric shaft and cycloidal wheel of current RV reducers, which affects their service life, and to provide an RV reducer for industrial robots.

[0006] The above objectives are achieved through the following technical solutions:

[0007] An RV reducer for use in industrial robots, comprising:

[0008] The housing contains an input shaft and a rotating frame rotatably mounted inside. The rotating frame is circumferentially and rotatably connected to three rotating shafts. Each of the three rotating shafts has a planetary gear fixedly mounted on one end, and each planetary gear meshes with the input shaft. Two eccentric wheels are axially positioned at the middle of each of the three rotating shafts. The axes of the two eccentric wheels are symmetrical about the axes of the rotating shafts. Two cycloidal wheels are arranged vertically on the outer periphery of the two eccentric wheels. Multiple needle rollers are circumferentially and evenly distributed on the inner wall of the housing. The outer periphery of the two cycloidal wheels contacts the multiple needle rollers.

[0009] A balancing assembly capable of balancing the eccentric loads exerted on the rotating shaft by two eccentric wheels when the shaft rotates about its own axis.

[0010] Furthermore, the balancing assembly includes a first channel and a second channel, both of which extend axially along the rotation shaft and are located inside the rotation shaft, with the first channel and the second channel respectively close to the axes of the two eccentric wheels.

[0011] Furthermore, the end of the first channel away from the second channel passes through one end of the rotating shaft, and the end of the second channel away from the first channel passes through the other end of the rotating shaft. The first channel and the second channel are connected, and the housing is provided with a grease inlet and a grease outlet.

[0012] Furthermore, an adjustment component is provided at the position where the first channel and the second channel connect. The adjustment component can adjust the size of the opening between the first channel and the second channel, and the size of the opening is positively correlated with the rotation speed of the rotating shaft.

[0013] Furthermore, the adjustment component includes two rotating blocks, which are rotatably connected to the first channel near the second channel and the second channel near the first channel, respectively. An opening is formed between the two rotating blocks, and each rotating block has an inclined surface. The inclined surfaces of the two rotating blocks are always parallel to each other. Each rotating block is provided with an elastic element, which makes the two rotating blocks tend to return to their original position.

[0014] Furthermore, both the first channel near the second channel and the second channel near the first channel are threadedly connected to locking blocks. A rotating ring is rotatably disposed inside the rotating block, and the rotating ring engages with the locking blocks. The elastic element is located between the rotating block and the rotating ring.

[0015] Furthermore, one end of the elastic element is fixedly connected to the inner circumference of the rotating block, and the other end of the elastic element is fixedly connected to the rotating ring.

[0016] Furthermore, an oil seal is slidably disposed inside the housing, the oil seal being used to seal the side of the housing away from the input shaft, and a sealing end cap is axially slidably disposed on the end of the rotating frame away from the input shaft.

[0017] Furthermore, a plurality of first sealing screws are threadedly connected to the side of the housing away from the input shaft. The first sealing screws pass axially through the oil seal and are fitted with a first compression spring on their outer circumference. The first compression spring pushes against the oil seal.

[0018] Furthermore, a plurality of second sealing screws are threadedly connected to one end of the rotating frame away from the input shaft. The second sealing screws pass axially through the sealing end cover and are fitted with a second compression spring on their outer circumference. The second compression spring pushes against the sealing end cover.

[0019] The beneficial effects of this invention are:

[0020] This invention reduces the mass of the rotating shaft in the axial region of the eccentric wheel axis by opening a first channel and a second channel inside the rotating shaft. The first channel and the second channel are respectively close to the axes of the two eccentric wheels, thereby minimizing the eccentric load generated when the eccentric wheels rotate and reducing the eccentric load force of the cycloidal wheel on the eccentric wheel. This avoids the increased gap between the rotating groove and the eccentric wheel and component damage caused by eccentric load in traditional RV reducers, extends the service life of the rotating shaft, eccentric wheel and cycloidal wheel, and reduces the vibration amplitude during operation, ensuring the smoothness of the joint transmission of industrial robots.

[0021] This invention connects the first and second channels, allowing the grease inside the housing to pass through them. A grease inlet and outlet are provided on the housing, enabling the grease to circulate within the housing, the first channel, and the second channel. As the grease flows, it quickly dissipates heat from core components such as the rotating shaft, eccentric wheel, and bearings, solving the problem of poor heat dissipation in traditional enclosed structures. This prevents lubrication failure due to grease thinning at high temperatures and reduces the risk of shaft seizure.

[0022] This invention provides an adjustment component at the connection point of the first and second channels. The adjustment component can adaptively adjust the size of the opening at the connection point of the first and second channels according to the rotational speed of the rotating shaft. The higher the rotational speed (the greater the heat generation), the greater the deflection amplitude of the rotating block under centrifugal force, the larger the opening, the faster the flow rate of the lubricating grease, and the higher the heat dissipation efficiency. When the rotational speed decreases, the opening automatically shrinks to avoid energy waste caused by excessive flow of lubricating grease and ensure that the reducer can maintain a suitable temperature under different loads. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of an RV reducer applied to an industrial robot according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the RV reducer applied to an industrial robot according to an embodiment of the present invention from another angle;

[0025] Figure 3 for Figure 1 A left view of an RV reducer used in an industrial robot, provided in one embodiment;

[0026] Figure 4 for Figure 3 A cross-sectional view along AA of an RV reducer used in an industrial robot at a low rotational speed, provided in one embodiment;

[0027] Figure 5 for Figure 3 An isometric view along section AA of an RV reducer used in an industrial robot at a low rotational speed, provided in one embodiment;

[0028] Figure 6 for Figure 4 A partial enlarged view of the X part of an RV reducer used in an industrial robot, provided in one embodiment;

[0029] Figure 7 for Figure 3 A cross-sectional view along AA of an RV reducer used in an industrial robot at a high rotational speed, provided in one embodiment;

[0030] Figure 8 for Figure 3 An isometric view along section AA of an RV reducer used in an industrial robot, provided in one embodiment, when the rotational speed of the rotating shaft is high.

[0031] Figure 9 for Figure 7 A partially enlarged view of the Y portion of an RV reducer used in an industrial robot, provided in one embodiment;

[0032] Figure 10 An exploded view of an RV reducer applied to an industrial robot according to an embodiment of the present invention;

[0033] Figure 11 A schematic diagram of the rotating shaft structure of an RV reducer applied to an industrial robot according to an embodiment of the present invention;

[0034] Figure 12 for Figure 11 A left view of the rotating shaft of an RV reducer used in an industrial robot, provided in one embodiment;

[0035] Figure 13 for Figure 12 A cross-sectional view along BB of the rotating shaft of an RV reducer used in an industrial robot, provided in one embodiment;

[0036] Figure 14 for Figure 12 An isometric view of the rotating shaft of an RV reducer used in an industrial robot, cut along BB, provided in one embodiment;

[0037] Figure 15 An exploded view of the rotating shaft of an RV reducer used in an industrial robot, according to an embodiment of the present invention;

[0038] Figure 16 An exploded view of the rotating block of an RV reducer applied to an industrial robot, according to an embodiment of the present invention.

[0039] in:

[0040] 100. Housing; 110. Input shaft; 111. Gear; 120. Rotating frame; 130. First rotating disk; 140. Connecting groove; 150. Bearing; 160. Second rotating disk; 170. Circular hole; 180. Rotating hole; 190. Connecting column;

[0041] 200. Rotating shaft; 210. First channel; 220. Second channel; 230. Rotating block; 231. Inclined surface; 232. Rotating ring; 233. Locking block; 240. Elastic element; 250. Planetary gear; 260. Eccentric wheel; 270. Cycloidal wheel; 271. Rotating groove; 280. Needle roller;

[0042] 300. Grease inlet; 310. Grease outlet;

[0043] 400, Oil seal; 410, First sealing screw; 420, First compression spring; 430, Sealing end cap; 440, Second sealing screw; 450, Second compression spring. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0045] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0047] The following reference Figures 1-16 This invention describes an RV reducer for use in industrial robots.

[0048] An RV reducer for industrial robots includes a housing 100. An input shaft 110 and a rotating frame 120 are rotatably disposed inside the housing 100. The input shaft 110 passes through the center of the rotating frame 120. Three rotating shafts 200 are circumferentially and uniformly rotatably connected to the rotating frame 120. The axes of the three rotating shafts 200 are parallel to each other and parallel to the axis of the rotating frame 120. One end of each of the three rotating shafts 200 is coaxially and fixedly mounted with a planetary gear 250. Each planetary gear 250 meshes with the input shaft 110. Specifically, a gear 111 is coaxially and fixedly mounted on one end of the input shaft 110 located inside the housing 100. 1. Engages with three planetary gears 250. The input shaft 110 is driven by a power source (not shown in the figure). The input shaft 110 drives the three planetary gears 250 to rotate synchronously. The three planetary gears 250 synchronously drive three rotating shafts 200 to rotate around their own axes. Two eccentric wheels 260 are axially positioned at the middle of each of the three rotating shafts 200. The two eccentric wheels 260 are vertically distributed and eccentrically positioned on the rotating shaft 200. The axes of the two eccentric wheels 260 are symmetrical about the axis of the rotating shaft 200. Cycloidal wheels 270 are arranged on the outer periphery of the two eccentric wheels 260. There are two cycloidal wheels 270, vertically distributed, as shown in the figure. Figure 4 , Figure 5 and Figure 10 As shown, the two cycloidal wheels 270 are eccentrically arranged, and each of the two cycloidal wheels 270 has three circumferentially oriented rotating grooves 271. A total of six eccentric wheels 260 are located on the outer periphery of the three rotating shafts 200, which are respectively located in the six rotating grooves 271 on the two cycloidal wheels 270. At the same time, multiple needle rollers 280 are evenly distributed circumferentially on the inner wall of the housing 100. The multiple needle rollers 280 contact the outer periphery of the cycloidal wheels 270. The outer periphery of the two cycloidal wheels 270 is provided with multiple arc-shaped protrusions, and the number of arc-shaped protrusions is one less than the number of needle rollers 280 inside the housing 100. The two eccentric wheels 260 on the outer periphery of the three rotating shafts 200 drive the two cycloidal wheels 270 to rotate eccentrically, thereby driving the rotating frame 120 to rotate around its own axis.

[0049] Understandably, the power source drives the input shaft 110 to rotate. The input shaft 110 undergoes a first-stage reduction through three planetary gears 250. Subsequently, the three planetary gears 250 drive three rotating shafts 200 to rotate. The three rotating shafts 200 drive two eccentric wheels 260. The two eccentric wheels 260 cause two cycloidal wheels 270 to rotate eccentrically, which in turn drives the rotating frame 120 to rotate. At this point, a second-stage reduction occurs, and the ratio of this second-stage reduction is much greater than the ratio of the first-stage reduction. The rotating frame 120 outputs the reduced power, thereby achieving the deceleration effect.

[0050] It should be noted that in the prior art, the RV reducer must rely on the two eccentric wheels 260 on the rotating shaft 200 to eccentrically drive the two cycloidal wheels 270 in order to achieve the function of speed reduction. However, the two eccentric wheels 260 on the rotating shaft 200 will give the rotating shaft 200 an eccentric load when the rotating shaft 200 rotates. In addition, the eccentric rotation of the cycloidal wheels 270 will cause the cycloidal wheels 270 to generate an eccentric load on the two eccentric wheels 260. After long-term operation, it is easy to cause the gap between the rotating groove 271 on the cycloidal wheel 270 and the eccentric wheel 260 to increase or damage the eccentric wheel 260. In fact, the existence of torque during rotation may cause the device to vibrate.

[0051] Based on this, the present invention provides a balancing component on the rotating shaft 200. The balancing component can balance the eccentric load of the two eccentric wheels 260 when the rotating shaft 200 rotates around its own axis, thereby reducing the eccentric load of the two eccentric wheels 260 on the rotating shaft 200, minimizing the increase in the distance between the rotating groove 271 on the cycloidal wheel 270 and the eccentric wheel 260, avoiding damage to the eccentric wheel 260, and significantly increasing the service life of the rotating shaft 200, the eccentric wheel 260, and the cycloidal wheel 270.

[0052] In this embodiment of the invention, the balancing component is a first channel 210 and a second channel 220, such as... Figure 13 and Figure 14 As shown, the first channel 210 and the second channel 220 both extend along the axial direction of the rotating shaft 200 and are located inside the rotating shaft 200. The first channel 210 and the second channel 220 are respectively close to the axes of the two eccentric wheels 260. The arrangement of the first channel 210 and the second channel 220 reduces the mass of the rotating shaft 200 near the axis of the eccentric wheel 260, thereby reducing the eccentric load generated when the eccentric wheel 260 rotates, reducing the influence of the eccentric load on the rotating shaft 200, making the rotating shaft 200 as balanced as possible, avoiding abnormal increase in the gap between the rotating groove 271 and the eccentric wheel 260, reducing component damage, extending the service life of the rotating shaft 200, the eccentric wheel 260 and the cycloidal wheel 270, and reducing the vibration amplitude during device operation.

[0053] It should be noted that the balancing component in this embodiment is not limited to the structure described above, and can also be other structures. For example, the balancing component can also be a balance block (not shown in the figure). The balance block can be set inside the eccentric wheel 260, so that the weight of the part of the eccentric wheel 260 that is off the axis of the rotating shaft 200 is increased, thereby reducing the eccentric load generated when the eccentric wheel 260 rotates, reducing the eccentric load force of the eccentric wheel 260 on the rotating shaft 200, and making the rotating shaft 200 subject to a balanced force as much as possible.

[0054] In a further embodiment, since the RV reducer used in industrial robots needs to start and stop frequently and withstand alternating loads (such as the continuous swing of welding robots and the heavy lifting of handling robots), the grease inside it will generate heat due to friction while lubricating parts and reducing wear. In the closed structure, the grease cannot dissipate heat naturally through air convection, and the heat will continue to accumulate. If the heat dissipation is not timely, when the internal temperature of the reducer exceeds 60°C, the grease will gradually become thinner (the viscosity will decrease), and the lubrication effect will be greatly weakened. This will lead to an accelerated wear rate between the cycloidal wheel 270 and the needle teeth, and in severe cases, it will cause a shaft seizure failure (cam crankshaft jamming), directly interrupting the robot's operation.

[0055] Therefore, this embodiment utilizes the first channel 210 and the second channel 220 for heat dissipation, making the first channel 210 and the second channel 220 connected. The end of the first channel 210 away from the second channel 220 passes through the lower end of the rotating shaft 200, and the end of the second channel 220 away from the first channel 210 passes through the upper end of the rotating shaft 200, so that the grease can flow in the first channel 210 and the second channel 220. Furthermore, a grease outlet 310 and a grease inlet 300 are provided on the housing 100, so that the grease can flow in the housing 100 to carry away heat and reduce the accumulation of heat inside the housing 100.

[0056] It should be noted that, to facilitate the rotatable connection of the three rotating shafts 200 to the rotating frame 120, the rotating frame 120 is provided with three connecting slots 140. Bearings 150 are installed within the three connecting slots 140. The inner circumference of the bearings 150 is coaxial with and fixedly connected to the rotating shafts 200, thus rotatably connecting the three rotating shafts 200 to the rotating frame 120. Since the input shaft 110 drives the rotating shafts 200 to rotate around their own axis via three planetary gears 250, and the rotating shafts 200 then drive two cycloidal wheels 270 to rotate via two eccentric wheels 260 on their outer circumference to achieve speed reduction, the outer circumference of the two eccentric wheels 260 and the cycloidal wheels 270... The rolling contact between the components and the rotation of the bearing 150 generate a large amount of heat. The rotating shaft 200 has a first channel 210 and a second channel 220 inside, which can dissipate the heat. Compared with the traditional RV reducer, which is enclosed and can only dissipate heat through grease, the grease in this embodiment can also flow in the first channel 210 and the second channel 220. This not only increases the space for the grease but also allows it to flow continuously, thus giving it a better heat dissipation effect and improving the overall heat dissipation efficiency of the RV reducer.

[0057] It should also be noted that the grease inlet 300 on the housing 100 is close to the axis of the rotating shaft 200. When the rotating frame 120 rotates, the axis of each rotating shaft 200 is brought close to the grease inlet, so that when the grease enters from the grease inlet 300, it can enter the first channel 210 and the second channel 220 inside the rotating shaft 200. The grease inside the first channel 210 and the second channel 220 enters the housing 100 under the lubricating pushing action of the grease inlet 300 and is finally discharged from the grease outlet 310.

[0058] To ensure continuous input and output of grease, a grease circulation system (not shown in the figure) is provided on the outside of the housing 100 in this embodiment. The grease circulation system circulates grease into the housing 100 and discharges it from the grease outlet 310. The discharged grease can be cooled by the grease circulation system and then re-enter the housing 100 from the grease inlet 300, thereby improving the heat dissipation capacity of the grease.

[0059] In a further embodiment, an adjustment component is provided at the position where the first channel 210 and the second channel 220 of the present invention connect. The adjustment component can adjust the size of the opening between the first channel 210 and the second channel 220, thereby adjusting the flow rate of the lubricating grease inside the first channel 210 and the second channel 220, that is, adjusting the heat dissipation rate. In this embodiment, the opening size is positively correlated with the rotation speed of the rotating shaft 200. If the rotation speed of the input shaft 110 is greater, the rotation speed of the rotating shaft 200 connected to it will also be greater, indicating that more heat is generated inside the housing 100. At this time, the opening of the first channel 210 and the second channel 220 will increase, thereby increasing the flow rate of the lubricating grease and thus increasing the heat dissipation. If the rotation speed of the rotating shaft 200 decreases, it means that less heat is generated inside the housing 100. At this time, the opening of the first channel 210 and the second channel 220 will be appropriately reduced, thereby appropriately reducing the flow rate of the lubricating grease and appropriately reducing the heat dissipation.

[0060] Specifically, the adjustment component in this embodiment includes two rotating blocks 230. The two rotating blocks 230 are rotatably connected to the first channel 210 near the second channel 220 and the second channel 220 near the first channel 210, respectively. Each rotating block 230 has an inclined surface 231, which are always parallel to each other. The inclined surfaces 231 guide grease from the second channel 220 into the first channel 210, preventing grease from accumulating at the connection point while flowing within the first and second channels 210. The inclined surfaces 231 of the two rotating blocks 230 are parallel to each other, such as... Figure 4 and Figure 6As shown, when the power source does not drive the input shaft 110 to rotate, the inclined surfaces 231 of the two rotating blocks 230 are always parallel to each other. At this time, the opening between the two rotating blocks 230 is small, meaning that less grease can pass through between the two rotating blocks 230. When the power source starts, it drives the three rotating shafts 200 to rotate around their own axes through the input shaft 110 and the three planetary gears 250. Because the rotating blocks 230 have inclined surfaces 231, the mass distribution of the rotating blocks 230 is not uniform. For example... Figure 6 The mass of the rotating block 230 on the left side is greater than that on the right side, and the side with the greatest mass is not at the position furthest from the axis of the rotating shaft 200 and the sidewall of the first channel 210. Therefore, when the rotating shaft 200 rotates around its own axis, the rotating block 230 is subjected to centrifugal force, causing its side with the greatest mass to tend to deflect towards the position furthest from the axis of the rotating shaft 200 and the sidewall of the first channel 210. If the centrifugal force is greater than the force that causes the rotating block 230 to deflect, the rotating block 230 will deflect. To ensure that the deflection distance of the rotating block 230 can be determined according to... The rotation speed of the rotating shaft 200 adapts to change adaptively. In this embodiment, an elastic element 240, which is a compression spring, is provided at the connection between the rotating block 230 and the first channel 210. The elastic element 240 enables the rotating block 230 to have a reaction force that causes it to deflect in the opposite direction when subjected to centrifugal force. In other words, the elastic element 240 enables the rotating block 230 to have the ability to return to its original position. The greater the centrifugal force, the greater the reaction force generated by the elastic element 240, and the greater the deflection distance of the rotating block 230. As the centrifugal force gradually decreases, the deflection distance of the rotating block 230 also gradually decreases. Similarly, the rotating block 230 on the right side is also like this, which will not be described in detail here.

[0061] It should be noted that as the rotational speed of the rotating shaft 200 gradually increases, the side with the largest mass on the two rotating blocks 230 gradually moves towards the position furthest from the axis of the rotating shaft 200 and the sidewall of the first channel 210 or the second channel 220. When the side with the largest mass on the two rotating blocks 230 deflects to the position furthest from the axis of the rotating shaft 200 and the sidewall of the first channel 210 or the second channel 220, the two rotating blocks 230 stop deflecting. At this point, the distance between the inclined surfaces 231 on the two rotating blocks 230 is the greatest, meaning the opening between the two rotating blocks 230 is the largest. As the rotational speed of the rotating shaft 200 gradually decreases, the two rotating blocks 230 gradually reset under the action of the elastic element 240, that is, they gradually move towards the position furthest from the axis of the rotating shaft 200 and the sidewall of the first channel 210 or the second channel 220. The two rotating blocks 230 gradually reset, and the distance between the inclined surfaces 231 on the two rotating blocks 230 gradually decreases, thereby reducing the size of the opening between the two rotating blocks 230.

[0062] In a further embodiment, to connect the two rotating blocks 230 to the first channel 210 and the second channel 220, in this embodiment, both the first channel 210 near the second channel 220 and the second channel 220 near the first channel 210 are threaded with locking blocks 233, such as... Figure 9 and Figure 16 As shown, the locking block 233 has a groove, and the rotating block 230 has a rotating ring 232 that is coaxially and rotatably mounted on its inner circumference. The rotating ring 232 has a protrusion on its inner circumference. The groove on the locking block 233 matches the protrusion on the rotating ring 232, allowing them to engage. In this embodiment, the elastic element 240 is located between the outer circumference of the rotating ring 232 and the inner circumference of the rotating block 230. One end of the elastic element 240 is fixedly connected to the inner circumference of the rotating block 230, and the other end is fixedly connected to the outer circumference of the rotating ring 232, thus giving the rotating block 230 a tendency to reset.

[0063] It should be noted that in the prior art, the RV reducer housing 100 is provided with multiple sealing oil rings, and the positions of these sealing oil rings are fixed, ensuring that the cavity inside the housing 100 that holds the grease remains constant. However, the grease will expand slightly in a high-temperature environment. Although the expansion rate is very low, the operator will still leave a small space for the grease to expand when filling the housing 100 with grease. This reduces the amount of grease inside the housing 100, which slightly affects the lubrication and heat dissipation effects of the grease. Therefore, in this invention, the housing 100 is located away from the input shaft 110. An oil seal 400 capable of elastic sliding and sealing is provided on one side of the housing 100. The oil seal 400 is annular. In this embodiment, the oil seal 400 is axially slidably disposed on the side of the housing 100 away from the input shaft 110. This allows the space inside the housing 100 for filling grease to be slightly increased, thereby accommodating the expansion of the grease. Compared with the prior art where the housing 100 is filled with grease, the present invention does not need to deliberately reserve space for the expansion of the grease, thus allowing for the filling of slightly more grease, thereby improving the lubrication and heat dissipation effect of the grease inside the housing 100.

[0064] In a further embodiment, the present invention provides an axially sliding sealing end cap 430 on the rotating frame 120 away from the input shaft 110. The space between the sealing end cap 430 and the interior of the rotating frame 120 also contains grease. This space is connected to the interior of the housing 100. Therefore, by axially sliding the sealing end cap 430 on the end of the rotating frame 120 away from the input shaft 110, and by elastically sliding it, the volume of the space between the sealing end cap 430 and the rotating frame 120 can be appropriately increased, which further increases the amount of grease filling and thus further improves the lubrication and heat dissipation effect of the grease.

[0065] Specifically, in this embodiment, a plurality of first sealing screws 410 are threadedly connected to the side of the housing 100 away from the input shaft 110. The plurality of first sealing screws 410 axially pass through the oil seal 400 and connect the oil seal 400 to the housing 100. A first compression spring 420 is sleeved on the outer periphery of the plurality of first sealing screws 410. One end of the first compression spring 420 is fixedly connected to the outer periphery of the first sealing screw 410, and the other end of the first compression spring 420 abuts against the oil seal 400. The first compression spring 420 pushes the oil seal 400 to connect to the housing 100. When the grease inside the housing 100 expands, it can push the oil seal 400 to move axially, thereby compressing the first compression spring 420, so that the oil seal 400 is elastically sliding and sealingly connected to the housing 100.

[0066] More specifically, in this embodiment, a plurality of second sealing screws 440 are threadedly connected to one end of the rotating frame 120 away from the input shaft 110. The plurality of second sealing screws 440 axially pass through the sealing end cover 430 and axially slide the sealing end cover 430 onto the rotating frame 120. A second compression spring 450 is sleeved on the outer periphery of the plurality of second sealing screws 440. One end of the second compression spring 450 is fixedly connected to the outer periphery of the second sealing screw 440, and the other end of the second compression spring 450 abuts against the sealing end cover 430, thereby making the sealing end cover 430 elastically slide onto the rotating frame 120.

[0067] It should be noted that, as Figure 10 As shown, the rotating frame 120 in this embodiment includes a first rotating disk 130 and a second rotating disk 160. Three connecting posts 190 are provided between the first rotating disk 130 and the second rotating disk 160, and the three connecting posts 190 fix the first rotating disk 130 and the second rotating disk 160 together. Three connecting slots 140 on the rotating frame 120 are opened on the first rotating disk 130, and three circular holes 170 corresponding to the three connecting slots 140 on the first rotating disk 130 are opened on the second rotating disk 160. Bearings 150 are also provided in the circular holes 170. One end of the three rotating shafts 200 passes through the three circular holes 170 on the second rotating disk 160 and is coaxial with and fixedly connected to the bearings 150. The planetary gears 250 are coaxially and fixedly connected to the end of the shafts passing through the circular holes 170. Meanwhile, a rotating hole 180 is provided at the center of both the second rotating disk 160 and the first rotating disk 130. The input shaft 110 passes through the two rotating holes 180 and is coaxially and fixedly mounted on one end of the rotating hole 180 on the second rotating disk 160. The gear 111 meshes with the three planetary gears 250.

[0068] It should also be noted that, such as Figure 2 and Figure 10As shown, the sealing end cap 430 in this embodiment is triangular, with rounded corners. Specifically, the sealing end cap 430 is axially slidably disposed at the bottom of the second rotating disk 160. The bottom of the second rotating disk 160 has a groove with the same shape as the sealing end cap 430, and the outer periphery of the sealing end cap 430 is slidably and sealingly connected to this groove. The power output position of this invention is specifically on the second rotating disk 160, and the bottom of the second rotating disk 160 can be connected to a designated position via a connecting flange (not shown in the figure). The sealing end cap 430 in this embodiment is provided with the aforementioned grease outlet 310, through which the grease inside the housing 100 can be discharged.

[0069] The specific working process of an RV reducer applied to an industrial robot provided by the present invention will be described in conjunction with the above embodiments:

[0070] Fill with grease:

[0071] During assembly, the operator fills the housing 100 with grease and then connects the grease circulation system (not shown in the figure) to the grease inlet 300 and the grease outlet 310. When the power source (not shown in the figure) is started to drive the input shaft 110 to rotate, the grease circulation system starts synchronously, thereby continuously inputting grease into the housing 100 and discharging it from the housing 100. The grease can circulate through the first channel 210 and the second channel 220 on the rotating shaft 200.

[0072] Adaptive adjustment of opening size:

[0073] Since two rotating blocks 230 are positioned close to each other in the first channel 210 and the second channel 220, the distance between the inclined surfaces 231 of the two rotating blocks 230 determines the size of the opening between the first channel 210 and the second channel 220. As the rotation speed of the input shaft 110 increases, the speed at which the gear 111 inside the housing 100 drives the three planetary gears 250 to rotate increases, and the speed at which the three planetary gears 250 drive the three rotating shafts 200 to rotate increases. Consequently, the rotation speeds of the two oscillating wheels and the rotating frame 120 also increase. Because the rotation speeds of the transmission components inside the housing 100 all increase, the heat generated inside the housing 100 also increases synchronously. At this time, the centrifugal force exerted on the two rotating blocks 230 in the first channel 210 and the second channel 220 by the rotation of the rotating shaft 200 increases. The two rotating blocks 230 gradually deflect towards the position furthest from the axis of the rotating shaft 200 and the sidewall of the first channel 210 or the second channel 220, overcoming the force of the elastic element 240. This causes the distance between the inclined surfaces 231 of the two rotating blocks 230 to gradually increase, thereby increasing the opening between the first channel 210 and the second channel 220 to allow more grease to pass through, thus increasing the flow rate of grease inside the first channel 210 and the second channel 220 and improving the heat dissipation capacity of the grease. Similarly, if the rotation speed of the input shaft 110 is relatively small, the rotation speed of the transmission components inside the housing 100 is also relatively slow, so the overall heat generation inside the housing 100 is not very large. At this time, the two rotating blocks 230 of the first channel 210 and the second channel 220 will gradually deflect to the position furthest from the axis of the rotating shaft 200 and the side wall of the first channel 210 or the second channel 220 under the action of the elastic element 240. That is, the distance between the inclined surfaces 231 of the two rotating blocks 230 decreases, thereby reducing the opening between the first channel 210 and the second channel 220 and appropriately reducing the flow rate of grease inside the first channel 210 and the second channel 220.

[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. An RV reducer for use in industrial robots, characterized in that, include: The housing contains an input shaft and a rotating frame rotatably mounted inside. The rotating frame is circumferentially and rotatably connected to three rotating shafts. Each of the three rotating shafts has a planetary gear fixedly mounted on one end, and each planetary gear meshes with the input shaft. Two eccentric wheels are axially positioned at the middle of each of the three rotating shafts. The axes of the two eccentric wheels are symmetrical about the axes of the rotating shafts. Two cycloidal wheels are arranged vertically on the outer periphery of the two eccentric wheels. Multiple needle rollers are circumferentially and evenly distributed on the inner wall of the housing. The outer periphery of the two cycloidal wheels contacts the multiple needle rollers. A balancing assembly capable of balancing the eccentric loads exerted on the rotating shaft by two eccentric wheels when the shaft rotates about its own axis; The balancing assembly includes a first channel and a second channel, both of which extend axially along the rotation shaft and are located inside the rotation shaft. The first channel and the second channel are respectively close to the axes of the two eccentric wheels. The end of the first channel away from the second channel passes through one end of the rotating shaft, and the end of the second channel away from the first channel passes through the other end of the rotating shaft. The first channel and the second channel are connected. The housing is provided with a grease inlet and a grease outlet. An adjustment component is provided at the position where the first channel and the second channel connect. The adjustment component can adjust the size of the opening between the first channel and the second channel. The size of the opening is positively correlated with the rotation speed of the rotating shaft. The adjustment assembly includes two rotating blocks, which are rotatably connected to the first channel near the second channel and the second channel near the first channel, respectively. An opening is formed between the two rotating blocks. Both rotating blocks have inclined surfaces, which are always parallel to each other. Each of the two rotating blocks is provided with an elastic element, which makes the two rotating blocks tend to return to their original position.

2. The RV reducer for industrial robots according to claim 1, characterized in that, Both the first channel near the second channel and the second channel near the first channel are threadedly connected to a locking block. A rotating ring is rotatably disposed inside the rotating block, and the rotating ring is engaged with the locking block. The elastic element is located between the rotating block and the rotating ring.

3. The RV reducer for industrial robots according to claim 2, characterized in that, One end of the elastic element is fixedly connected to the inner circumference of the rotating block, and the other end of the elastic element is fixedly connected to the rotating ring.

4. The RV reducer for industrial robots according to claim 1, characterized in that, An oil seal is slidably disposed inside the housing, and the oil seal is used to seal the side of the housing away from the input shaft. A sealing end cap is axially slidably sealed on the end of the rotating frame away from the input shaft.

5. The RV reducer for industrial robots according to claim 4, characterized in that, Multiple first sealing screws are threaded onto the side of the housing away from the input shaft. The first sealing screws pass axially through the oil seal and are fitted with first compression springs on their outer circumference. The first compression springs push against the oil seal.

6. The RV reducer for industrial robots according to claim 4, characterized in that, Multiple second sealing screws are threaded onto one end of the rotating frame away from the input shaft. The second sealing screws pass axially through the sealing end cover and are fitted with second compression springs on their outer circumference. The second compression springs push against the sealing end cover.

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