Harmonic reducer and industrial robot

Abstract

This invention discloses a harmonic reducer and an industrial robot, relating to the field of reducer technology. The harmonic reducer includes a flexible wheel, a rigid wheel, a wave generator, a support bearing, a seal, and an oil seal. A first gap exists between the inner ring of the support bearing and the diaphragm of the flexible wheel. A second gap exists between the outer side of the inner ring away from the diaphragm and the corresponding position of the inner side of the outer ring. The first and second gaps are located at opposite ends of the raceway. The seal seals the first gap, and the oil seal seals the second gap. The seal includes a first sealing portion and a second sealing portion connected together. The first sealing portion extends axially along the flexible wheel and abuts against the inner side of the outer ring of the support bearing. The second sealing portion extends radially along the flexible wheel and abuts against the end face of the inner ring facing the diaphragm, forming at least two levels of sealing. This invention significantly improves the sealing performance of the harmonic reducer through the combined action of the seal and the oil seal, effectively suppressing lubricant leakage.

Description

Technical Field

[0001] This invention relates to the field of speed reducer technology, and in particular to a harmonic speed reducer and an industrial robot. Background Technology

[0002] Harmonic reducers are widely used in robotics, electronics, aerospace, and automation industries due to their advantages such as compact structure, small size, light weight, high transmission ratio and load capacity, and high transmission accuracy. As the application market for harmonic reducers expands, for example in food processing equipment, the high hygiene requirements of food processing environments necessitate particularly stringent sealing requirements for harmonic reducers. Leakage is virtually unacceptable, and existing products in this field cannot meet these stringent sealing requirements. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a harmonic reducer that can significantly improve sealing performance.

[0004] The present invention also proposes an industrial robot having the above-mentioned harmonic reducer.

[0005] According to a first aspect of the present invention, a harmonic reducer includes: a flexible gear comprising a cylindrical portion, a diaphragm portion, and a flange portion, wherein an external tooth portion is provided on the outer side of one end of the cylindrical portion, the diaphragm portion is connected to the other end of the cylindrical portion and extends radially outward along the cylindrical portion, and the flange portion is connected to the end of the diaphragm portion away from the cylindrical portion; a rigid gear having an inner bore arranged around the outer side of the cylindrical portion, the bore wall of the inner bore having an internal tooth portion; a wave generator mounted on the inner side of the cylindrical portion, the wave generator being configured to partially mesh the external tooth portion with the internal tooth portion; and a support bearing configured to enable the flexible gear and the rigid gear to rotate relative to each other, the support bearing comprising an inner ring, an outer ring, and a ring formed between the inner ring and the outer ring. The raceway contains rolling elements, with the inner ring and the rigid wheel fixedly connected, and the outer ring and the flange fixedly connected. A first gap exists between the inner ring and the diaphragm, and a second gap exists between the outer side of the inner ring away from the diaphragm and the corresponding inner side of the outer ring. The first gap and the second gap are located at opposite ends of the raceway. A sealing element is used to seal the first gap. The sealing element includes a first sealing portion and a second sealing portion connected together. The first sealing portion extends axially along the flexible wheel and abuts against the inner side of the outer ring. The second sealing portion extends radially along the flexible wheel and is inserted into the first gap, abutting against the end face of the inner ring facing the diaphragm. An oil seal is used to seal the second gap.

[0006] The harmonic reducer according to embodiments of the present invention has at least the following beneficial effects: By setting an oil seal to seal the second gap on the outer side of the raceway of the support bearing, and setting a sealing element to seal the first gap on the side of the raceway near the diaphragm of the flexure, the sealing element includes a first sealing part and a second sealing part connected to each other. The first sealing part extends axially along the flexure and abuts against the inner side of the outer ring of the support bearing, and the second sealing part extends radially along the flexure and abuts against the end face of the inner ring facing the diaphragm, forming at least two levels of sealing. Under the combined action of the sealing element and the oil seal, the sealing performance of the harmonic reducer is greatly improved, effectively suppressing the leakage of lubricant.

[0007] According to some embodiments of the present invention, the flange includes a thickened region protruding inward from the inner side of the outer ring, and the second sealing portion further abuts against one end of the thickened region toward the inner ring.

[0008] According to some embodiments of the present invention, the seal further includes a third sealing portion connected to the second sealing portion, the third sealing portion extending axially along the flexible wheel and inserted into a third gap between the inner ring and the cylindrical portion, the third sealing portion abutting against the side of the inner ring facing the cylindrical portion.

[0009] According to some embodiments of the present invention, the seal is annular; the first sealing portion includes a first protrusion abutting against the inner side surface of the outer ring, the first protrusion being annular and the width of its cross-section gradually decreasing towards the abutting surface; and / or, the second sealing portion includes a second protrusion abutting against the end face of the inner ring facing one end of the diaphragm, the second protrusion being annular and the width of its cross-section gradually decreasing towards the abutting surface; and / or, the third sealing portion includes a third protrusion abutting against the side surface of the inner ring facing the cylindrical portion, the third protrusion being annular and the width of its cross-section gradually decreasing towards the abutting surface.

[0010] According to some embodiments of the present invention, the seal includes a retainer and a sealing body. The retainer includes a first inner ring and a second inner ring connected to each other. The sealing body wraps around at least a portion of the first inner ring and at least a portion of the second inner ring. The first inner ring abuts against the inner side of the outer ring through the sealing body, and the second inner ring abuts against the end face of the inner ring facing the diaphragm through the sealing body.

[0011] According to some embodiments of the present invention, the retainer further includes a third ring body connected to the second inner ring body, and the sealing body further wraps around at least a portion of the third ring body, the third ring body abutting against the side of the inner ring facing the cylindrical portion via the sealing body.

[0012] According to some embodiments of the present invention, the sealing body is wrapped around the outside of the retainer, and the material of the sealing body is an elastic sealing material.

[0013] According to some embodiments of the present invention, the inner ring includes a first annular body and a second annular body fixedly connected together. The first annular body is located at one end near the diaphragm, and the second annular body is located at one end near the rigid wheel and fixedly connected to the rigid wheel. The first annular body and the second annular body are fixedly connected by a first screw.

[0014] According to some embodiments of the present invention, the second sealing portion includes a second protrusion abutting against the end face of the inner ring facing one end of the diaphragm, the second protrusion and the first screw being arranged radially spaced along the flexible wheel.

[0015] According to some embodiments of the present invention, the seal further includes a third sealing portion connected to the second sealing portion, the third sealing portion including a third protrusion abutting against the side of the inner ring facing the cylindrical portion, the third protrusion abutting against the first annular body and / or the second annular body.

[0016] According to some embodiments of the present invention, the outer ring includes a second mounting portion and a protrusion connected to the inner side of the second mounting portion. The protrusion has a first outer raceway and a second outer raceway that are opposite to each other at both ends along the axial direction. The outer side of the inner ring has a groove that is opposite to the protrusion. The groove has a first inner raceway and a second inner raceway at both ends along the axial direction. The rolling element includes a first steel ball and a second steel ball. The first inner raceway and the first outer raceway are opposite to each other and form a first groove for accommodating the first steel ball. The second inner raceway and the second outer raceway are opposite to each other and form a second groove for accommodating the second steel ball.

[0017] An industrial robot according to a second aspect of the present invention includes the harmonic reducer described in the above embodiments.

[0018] The industrial robot according to embodiments of the present invention has at least the following beneficial effects: The harmonic reducer using the first aspect embodiment has a two-stage seal formed by providing an oil seal to seal the second gap on the outer side of the raceway of the support bearing, and a sealing element to seal the first gap on the side of the raceway near the diaphragm of the flexure. The sealing element includes a first sealing part and a second sealing part connected to each other. The first sealing part extends axially along the flexure and abuts against the inner side of the outer ring of the support bearing, and the second sealing part extends radially along the flexure and abuts against the end face of the inner ring facing the diaphragm. Under the combined action of the sealing element and the oil seal, the sealing performance of the harmonic reducer is greatly improved, effectively suppressing the leakage of lubricant.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of the structure of a harmonic reducer according to an embodiment of the present invention; Figure 2 for Figure 1 A partially enlarged view of the harmonic reducer shown; Figure 3 for Figure 2 A partial enlarged view of one embodiment of the central sealing element; Figure 4 for Figure 2 A partially enlarged view of another embodiment of the central sealing element; Figure 5 for Figure 2 A partially enlarged view of another embodiment of the central sealing element; Figure 6 This is a schematic diagram of the structure of a harmonic reducer according to another embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of a harmonic reducer according to another embodiment of the present invention; Figure 8 for Figure 7 A magnified view of a portion of the central sealing component; Figure 9 This is a partially enlarged view of the outer and inner rings according to an embodiment of the present invention.

[0021] Icon labels: Harmonic reducer 1000; Flexible wheel 100; cylindrical part 110; external toothed part 111; diaphragm part 120; flange part 130; thickened area 131; 200mm rigid wheel; 210mm inner diameter; 220mm internal gear; Wave generator 300; Cam 310; Flexible bearing 320; Support bearing 400; Inner ring 410; First clearance 411; Second clearance 412; Third clearance 413; First annular body 414; Second annular body 415; First inner raceway 416; Second inner raceway 417; First screw 418; Outer ring 420; Protrusion 421; First outer raceway 422; Second outer raceway 423; Fourth clearance 424; Rolling element 430; First steel ball 431; Second steel ball 432; Raceway 440; First groove 441; Second groove 442; Seal 500; First sealing part 510; First protrusion 511; Second sealing part 520; Second protrusion 521; Third sealing part 530; Third protrusion 531; Retainer 540; First inner ring 541; Second inner ring 542; Third inner ring 543; Sealing body 550; Oil seal 600. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to 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 a limitation of this invention.

[0024] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0025] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0026] To address the aforementioned technical problems, embodiments of the present invention provide a harmonic reducer. By using oil seals and sealing elements to seal both sides of the raceway of the supporting bearing, the leakage path of the lubricant is sealed. The sealing elements employ at least two levels of sealing, significantly improving the sealing performance of the harmonic reducer. The harmonic reducer of this invention will be described below with reference to the accompanying drawings.

[0027] Reference Figure 1 and Figure 2As shown, a harmonic reducer 1000 according to an embodiment of the present invention includes a flexible wheel 100, a rigid wheel 200, a wave generator 300, a support bearing 400, and an oil seal 600. The flexible wheel 100 is coaxially mounted inside the rigid wheel 200, and the wave generator 300 is coaxially mounted in the inner hole 210 of the flexible wheel 100. The flexible wheel 100 includes a cylindrical portion 110, a diaphragm portion 120, and a flange portion 130. The cylindrical portion 110 is located at the end of the flexible wheel 100 near the rigid wheel 200. The diaphragm portion 120 is connected to the end of the cylindrical portion 110 away from the rigid wheel 200 and extends outward from the cylindrical portion 110. The flange portion 130 is connected to the outer periphery of the diaphragm portion 120. The cylindrical portion 110 of the flexible wheel 100 is provided with a flexible external tooth portion 111, and the rigid wheel 200 is provided with a rigid internal tooth portion 220. The wave generator 300 is configured to partially mesh the external tooth portion 111 with the internal tooth portion 220.

[0028] Reference Figure 2 As shown, the support bearing 400 is sleeved on the outside of the cylindrical portion 110 and configured to allow the flexible gear 100 and the rigid gear 200 to rotate relative to each other. The support bearing 400 includes an inner ring 410, an outer ring 420, and a plurality of rolling elements 430. The outer ring 420 surrounds the outer side of the inner ring 410 and is spaced apart from the inner ring 410. A raceway 440 is formed between the outer ring 420 and the inner ring 410, and the plurality of rolling elements 430 are disposed within the raceway 440, which facilitates relative rotation between the outer ring 420 and the inner ring 410. The inner ring 410 is fixedly connected to the rigid gear 200, and the outer ring 420 is fixedly connected to the flange portion 130 of the flexible gear 100. The fixed connection can be achieved by fastener connection, welding, bonding, etc. The leakage path of the lubricant inside the harmonic reducer 1000 is shown in the figure. Figure 2 As shown, Figure 2 The dashed arrows indicate the leakage path of the lubricant. The lubricant sequentially passes through the inner hole 210 of the flexible wheel 100, the gap between the outer tooth section 111 and the inner tooth section 220, the gap between the inner ring 410 and the cylindrical section 110 of the support bearing 400, the gap between the inner ring 410 and the diaphragm 120 of the support bearing 400, the raceway 440 between the inner ring 410 and the outer ring 420 of the support bearing 400, and the gap between the outer circle of the inner ring 410 and the inner hole 210 of the outer ring 420 of the support bearing 400, finally seeping out of the harmonic reducer 1000. This results in insufficient lubrication of the harmonic reducer 1000, accelerated wear, and reduced service life.

[0029] To improve the sealing performance of the harmonic reducer 1000, refer to Figure 2 and Figure 3As shown, in an embodiment of the present invention, a first gap 411 is provided between the end of the inner ring 410 and the diaphragm 120, and a second gap 412 is provided between the outer side of the end of the inner ring 410 away from the diaphragm 120 and the corresponding position of the inner side of the outer ring 420. The first gap 411 and the second gap 412 are respectively located at both ends of the raceway 440 along the axial direction of the cylinder 110, and the inner ring 410 and the cylinder 110 are spaced apart. A third gap 413 is provided between the inner ring 410 and the cylinder 110, and the third gap 413 is provided around the cylinder 110. An oil seal 600 is provided in the second gap 412 and is used to seal the second gap 412. The oil seal 600 and the outer ring 420 are coaxially arranged, and the outer circle of the oil seal 600 and the inner hole 210 of the outer ring 420 are interference-fitted, and the inner hole 210 of the oil seal 600 and the outer wall of the inner ring 410 are in sealing contact. When the outer ring 420 and the inner ring 410 rotate relative to each other, the oil seal 600 also moves relative to the inner ring 410. However, the oil seal 600 can still maintain a seal with the outer wall of the inner ring 410, forming a radial contact seal, thereby preventing the lubricant in the raceway 440 from seeping out through the second gap 412 and ensuring continuous lubrication of the support bearing 400.

[0030] The harmonic reducer 1000 also includes a seal 500 for sealing the first gap 411. The seal 500 includes a first sealing portion 510, a second sealing portion 520, and a third sealing portion 530, which are sequentially connected. The first sealing portion 510 extends axially along the flexure 100 and abuts against the inner side of the outer ring 420. For example, the first sealing portion 510 and the inner hole 210 of the outer ring 420 are press-fitted together by an interference fit. The second sealing portion 520 extends radially along the flexure 100 and is inserted into the first gap 411. The second sealing portion 520 abuts against the end face of the inner ring 410 facing the diaphragm 120, and together with the first sealing portion 510, seals one axial end of the raceway 440. Meanwhile, in order to further improve the sealing performance, the third sealing part 530 extends along the axial direction of the flexible wheel 100 and is inserted into the third gap 413 between the inner ring 410 and the cylindrical part 110. The third sealing part 530 seals against the side of the inner ring 410 facing the cylindrical part 110.

[0031] It is understood that the second sealing part 520 in this embodiment of the invention constitutes the first-level seal, and the third sealing part 530 constitutes the second-level seal. By adopting a two-level sealing method and cooperating with the oil seal 600 to seal the second gap 412, the lubricant is difficult to leak from the raceway 440, and the lubricant in other positions of the harmonic reducer 1000 is also difficult to leak through the leakage path. Therefore, the sealing performance of the harmonic reducer 1000 is greatly improved, effectively suppressing the occurrence of lubricant leakage, so that the harmonic reducer 1000 can be applied to food-related equipment, effectively reducing the occurrence of food contamination caused by lubricant leakage.

[0032] In addition to employing a two-stage sealing method, seal 500 can also utilize a single-stage sealing method in equipment where sealing requirements are not particularly stringent. For example, refer to... Figure 7 and Figure 8 As shown, in another embodiment of the present invention, the structure of the harmonic reducer 1000 is similar to that of the harmonic reducer 1000 in the above embodiment, and will not be described again here. The main difference is that the sealing element 500 in this embodiment includes a first sealing part 510 and a second sealing part 520 connected to each other, but does not include a third sealing part 530. The first sealing part 510 extends axially along the flexible wheel 100 and abuts against the inner side of the outer ring 420, and the second sealing part 520 extends radially along the flexible wheel 100 and is inserted into the first gap 411. The second sealing part 520 abuts against the end face of the inner ring 410 facing the diaphragm 120. Therefore, the first sealing part 510 and the second sealing part 520 jointly seal the first gap 411, which can also improve the sealing effect of the harmonic reducer 1000 to a certain extent, reduce production costs, and meet the sealing requirements of related equipment. It should be noted that, for ease of explanation, the following embodiments will be described with the sealing element 500 also including a third sealing part 530 as an example.

[0033] Reference Figure 2 and Figure 3 As shown, in an embodiment of the present invention, the second sealing part 520 also seals against the diaphragm part 120 and / or the flange part 130, so that the sealing member 500 has a two-stage seal facing the inner ring 410, and also forms a two-stage seal on the side facing away from the inner ring 410, which further improves the sealing performance of the raceway 440, effectively preventing the lubricant in the raceway 440 from seeping into the first gap 411, and also effectively preventing the lubricant in the flexible wheel 100 from seeping out of the harmonic reducer 1000 through the first gap 411.

[0034] Continue to refer to Figure 2 and Figure 3As shown, in an embodiment of the present invention, the flange portion 130 includes a thickened region 131 that protrudes inwardly and radially from the inner side of the outer ring 420. The thickness of the thickened region 131 along the axial direction of the flexible wheel 100 is greater than the thickness of the diaphragm portion 120, and the second sealing portion 520 abuts against the side of the thickened region 131 facing the inner ring 410. It is understood that the diaphragm portion 120 has a certain degree of flexibility and can deform to a certain extent, while the thickness of the thickened region 131 of the flange portion 130 is greater than the thickness of the diaphragm portion 120. Therefore, the structure of the thickened region 131 is relatively stable. Under the abutment of the second sealing portion 520, the deformation of the thickened region 131 is very small or there is no deformation, thereby avoiding the situation where the flexible wheel 100 cannot provide sufficient support for the second sealing portion 520 during the deformation movement, resulting in lubricant leakage. Therefore, this embodiment has a reasonable structural design by providing a thickened area 131 in the flange portion 130 and having the second sealing portion 520 abut against the thickened area 131, which can effectively improve the sealing performance of the harmonic reducer 1000 and reduce lubricant leakage.

[0035] Reference Figure 2 and Figure 3 As shown, in the embodiments of the present invention, the sealing element 500 is annular and surrounds the cylindrical portion 110, forming a reliable seal between the contact surfaces. The design is simple, low-cost, and relatively easy to manufacture. The first sealing portion 510 includes a first protrusion 511, which abuts against the inner side of the outer ring 420. The first protrusion 511 is annular and surrounds the cylindrical portion 110, and the cross-sectional width of the first protrusion 511 gradually decreases towards the contact surface. It is understood that the gradual decrease in the cross-sectional width of the first protrusion 511 towards the contact surface makes the structure of the first protrusion 511 towards the contact surface more prone to deformation, which facilitates a tighter fit between the first protrusion 511 and the contact surface, thereby increasing the contact area, effectively improving the pressure distribution uniformity of the sealing contact surface, and avoiding leakage problems caused by insufficient contact area. Meanwhile, since there is relative rotation between the outer ring 420 and the inner ring 410, there is also relative rotation between the outer ring 420 and the seal 500. This is achieved through contact between the first protrusion 511 and the abutment surface, similar to line contact. Compared to surface contact, line contact effectively reduces the friction between the outer ring 420 and the seal 500 during relative rotation, thereby reducing the starting torque of the harmonic reducer 1000.

[0036] Continue to refer to Figure 3As shown, in embodiments of the present invention, multiple first protrusions 511 may be provided, and the multiple first protrusions 511 are spaced apart along the axial direction of the flexible wheel 100. For example, two first protrusions 511 are provided, and both first protrusions 511 protrude toward the inner side of the outer ring 420, which can further improve the sealing performance between the inner side of the outer ring 420 and the first sealing part 510, thereby reducing lubricant leakage and improving the sealing performance of the harmonic reducer 1000.

[0037] Reference Figure 2 and Figure 3 As shown in the embodiment of the present invention, the second sealing portion 520 includes a plurality of second protrusions 521, which are annular and surround the cylindrical portion 110. A portion of the second protrusions 521 abut against the end face of the inner ring 410 facing the diaphragm 120, and another portion of the second protrusions 521 abut against the flange portion 130. The cross-sectional width of the second protrusions 521 gradually decreases towards the abutting surface. It is understood that the gradual decrease in cross-sectional width of the second protrusions 521 towards the abutting surface makes the structure of the second protrusions 521 facing the abutting surface more prone to deformation, which facilitates a tighter fit between the second protrusions 521 and the abutting surface, thereby increasing the contact area, effectively improving the pressure distribution uniformity of the sealing abutting surface, and avoiding leakage problems caused by insufficient contact area. Simultaneously, since there is relative rotation between the outer ring 420 and the inner ring 410, there is also relative rotation between the outer ring 420 and the sealing element 500. The contact method between the second protrusions 521 and the abutting surface is similar to line contact. Compared to surface contact, this effectively reduces the friction between the outer ring 420 and the first sealing part 510 during relative rotation, thereby reducing the starting torque of the harmonic reducer 1000.

[0038] Continue to refer to Figure 3 As shown, in an embodiment of the present invention, multiple second protrusions 521 abutting against the inner ring 410 are provided, and the multiple second protrusions 521 are arranged radially spaced along the flexible wheel 100. By providing multiple second protrusions 521 abutting against the inner ring 410, the sealing performance between the second sealing portion 520 and the inner ring 410 can be further improved, and lubricant leakage can be reduced. Multiple second protrusions 521 abutting against the flange portion 130 are also provided, and the multiple second protrusions 521 are similarly arranged radially spaced along the flexible wheel 100. By providing multiple second protrusions 521 abutting against the flange portion 130, the sealing performance between the second sealing portion 520 and the flange portion 130 can be further improved, and lubricant leakage can also be reduced, thereby improving the sealing performance of the harmonic reducer 1000.

[0039] Reference Figure 2 and Figure 3As shown, in an embodiment of the present invention, the third sealing portion 530 includes a third protrusion 531, which abuts against the inner side surface of the inner ring 410. The third protrusion 531 is annular and surrounds the cylindrical portion 110. The cross-sectional width of the third protrusion 531 gradually decreases towards the abutting surface. It is understood that the gradual decrease in the cross-sectional width of the third protrusion 531 towards the abutting surface makes the structure of the third protrusion 531 more prone to deformation, which facilitates a tighter fit between the third protrusion 531 and the abutting surface, thereby increasing the contact area, effectively improving the pressure distribution uniformity of the sealing abutting surface, and avoiding leakage problems caused by insufficient contact area. In an embodiment of the present invention, multiple third protrusions 531 may be provided, and the multiple third protrusions 531 are spaced apart along the axial direction of the flexible wheel 100. For example, there are two third protrusions 531, both of which protrude toward the inner side of the inner ring 410, which can further improve the sealing between the inner side of the inner ring 410 and the third sealing part 530, thereby reducing lubricant leakage and improving the sealing performance of the harmonic reducer 1000.

[0040] Reference Figure 3 , Figure 4 and Figure 5 As shown, in embodiments of the present invention, the cross-sections of the first protrusion 511, the second protrusion 521, and the third protrusion 531 can be semi-circular, triangular, or trapezoidal; alternatively, the cross-section of the first protrusion 511 can be semi-circular, the cross-section of the second protrusion 521 can be triangular, and the cross-section of the third protrusion 531 can be trapezoidal. The appropriate solution is selected based on the actual situation. It is understood that when the cross-section of a protrusion (the protrusion refers to any one of the first protrusion 511, the second protrusion 521, and the third protrusion 531) is semi-circular, the semi-circular cross-section design has good elastic deformation capability, which can adapt to the compression changes of the seal 500 to a certain extent without affecting the sealing performance. When the cross-section of a protrusion is triangular, triangular protrusions are generally used in applications requiring high strength and high durability. For example, in some special sealing groove designs, protrusions with an equilateral right-angled triangle cross-section can provide a larger compression amount and a good sealing effect. When the cross-section of a protrusion is trapezoidal, the trapezoidal cross-section design can reduce the slippage of the seal 500 and improve sealing reliability.

[0041] Reference Figure 3As shown, in an embodiment of the present invention, the seal 500 includes a retainer 540 and a sealing body 550. The retainer 540 is made of a metal material, such as steel, so the retainer 540 is not easily deformed and has good structural stability. The retainer 540 includes a first inner ring 541, a second inner ring 542, and a third inner ring 543, which are connected sequentially. The first inner ring 541 extends axially along the flexible wheel 100, while the second inner ring 542 extends radially along the flexible wheel 100. The third inner ring 543 extends axially along the flexible wheel 100 and is spaced apart from the first inner ring 541 radially from the first inner ring 541. The sealing body 550 encloses at least a portion of the structure of the first inner ring 541, at least a portion of the structure of the second inner ring 542, and at least a portion of the structure of the third inner ring 543. The first inner ring 541 abuts against the inner side of the outer ring 420 via a sealing body 550; the second inner ring 542 abuts against the end face of the inner ring 410 facing the diaphragm 120 in a sealing manner; and the third inner ring 543 abuts against the inner side of the inner ring 410 via a sealing body 550. The first inner ring 541 and the corresponding sealing body 550 enclosing the first inner ring 541 are configured as a first sealing portion 510; the second inner ring 542 and the corresponding sealing body 550 enclosing the second inner ring 542 are configured as a second sealing portion 520; and the third inner ring 543 and the corresponding sealing body 550 enclosing the third inner ring 543 are configured as a third sealing portion 530.

[0042] Understandably, the flexible seal 550, when used alone, is prone to losing its resilience due to plastic deformation. The metal retainer 540, acting as a "skeleton," limits the deformation range of the seal 550, ensuring it maintains its designed shape and preventing excessive deformation under high pressure, vibration, or prolonged compression. Simultaneously, the retainer 540 evenly distributes external loads (such as bolt preload and fluid pressure) across the entire seal 550, preventing stress concentration that could lead to tearing or wear. The metal retainer 540 also ensures the geometric stability of the seal 500 (such as inner diameter, outer diameter, and concentricity), facilitating precise assembly.

[0043] Reference Figure 3 As shown, in an embodiment of the present invention, the sealing body 550 is wrapped around the outside of the retainer 540. For example, the sealing body 550 is integrally formed on the outside of the retainer 540, and the material of the sealing body 550 is an elastic material. For example, the material of the sealing body 550 can be rubber, silicone, elastic plastic, etc. For example, the sealing body 550 can be made of NBR nitrile rubber or FKM fluororubber, thereby ensuring that the sealing body 550 has good sealing performance.

[0044] Reference Figure 6As shown, in an embodiment of the present invention, the inner ring 410 includes a first annular body 414 and a second annular body 415. The first annular body 414 and the second annular body 415 are fixedly connected by a first screw 418. The second protrusion 521 and the first screw 418 are arranged radially spaced along the flexible wheel 100, thereby avoiding contact between the second protrusion 521 and the first screw 418, which would cause a gap between the second protrusion 521 and the end face of the outer ring 420. The first annular body 414 is located at one end near the diaphragm 120, and the second annular body 415 is located at one end near the rigid wheel 200 and is fixedly connected to the rigid wheel 200 by a second screw. The first annular body 414 is provided with one of a positioning groove and a positioning protrusion for positioning engagement, and the second annular body 415 is provided with the other of a positioning groove and a positioning protrusion. The positioning protrusion and the positioning groove are positioned and engaged, thereby facilitating the installation of the first annular body 414 and the second annular body 415. The inner ring 410 employs a first annular body 414 and a second annular body 415 to facilitate the installation of the rolling element 430. Before installing the rolling element 430, the first annular body 414 and the second annular body 415 remain separate. After the rolling element 430 is installed into the raceway 440, the first annular body 414 is connected to the second annular body 415, thereby preventing the rolling element 430 from detaching from the raceway 440. Therefore, the inner ring 410 has a reasonable structural design, which facilitates the assembly of the rolling element 430 and improves assembly efficiency.

[0045] Reference Figure 2 As shown, in an embodiment of the present invention, the third protrusion 531 of the third sealing portion 530 abuts against the second annular body 415. Therefore, the gap between the first annular body 414 and the second annular body 415 is located between the third protrusion 531 and the second protrusion 521, thereby preventing lubricant from leaking through the gap between the first annular body 414 and the second annular body 415, and thus improving the sealing performance of the raceway 440. Or refer to Figure 6 As shown, the third protrusion 531 of the third sealing portion 530 abuts against the first annular body 414, thus shortening the overall length of the third sealing portion 530. This ensures sealing performance while reducing processing difficulty and manufacturing costs. Alternatively, multiple third protrusions 531 may be provided, with some abutting against the first annular body 414 and others abutting against the second annular body 415. The sealing position of the third protrusion 531 is selected according to the actual situation.

[0046] Reference Figure 9As shown, in an embodiment of the present invention, the outer ring 420 includes a second mounting portion and a protrusion 421 connected to the inner side of the second mounting portion. The protrusion 421 has a first outer raceway 422 and a second outer raceway 423 respectively disposed opposite to each other at both ends along the axial direction. The outer side of the inner ring 410 has a groove disposed opposite to the protrusion 421. The groove has a first inner raceway 416 and a second inner raceway 417 respectively disposed at both ends along the axial direction. For example, the first inner raceway 416 is disposed in the first annular body 414, and the second inner raceway is disposed in the second annular body 415. The rolling element 430 includes a first steel ball 431 and a second steel ball 432; the first inner raceway 416 and the first outer raceway 422 are disposed opposite to each other and form a first groove 441 for accommodating the first steel ball 431; the second inner raceway 417 and the second outer raceway 423 are disposed opposite to each other and form a second groove 442 for accommodating the second steel ball 432; and the first groove 441 and the second groove 442 constitute a raceway 440. By adopting the above solution, the support bearing 400 can simultaneously withstand loads in multiple directions, including axial, radial, and overturning moments, thereby improving its rigidity and load-bearing capacity. Furthermore, the arrangement of the double-row rolling elements 430 not only optimizes load distribution but also enhances the rotational accuracy and stability of the support bearing 400, effectively reducing friction, extending service life, and meeting the demands of high-speed operation.

[0047] Continue to refer to Figure 9 As shown, in an embodiment of the present invention, a fourth gap 424 is provided between the protrusion 421 and the bottom wall of the groove. The first groove 441 is connected to the second groove 442 through the fourth gap 424, which facilitates the flow of lubricating oil between the first groove 441 and the second groove 442, thereby providing better lubrication for the rolling element 430, delaying the friction and wear between the raceway 440 and the rolling element 430, and improving the service life of the support bearing 400.

[0048] An embodiment of the present invention provides an industrial robot, including the harmonic reducer 1000 described in the above embodiments. The industrial robot can be a handling robot, welding robot, assembly robot, processing robot, painting robot, cleanroom robot, collaborative robot, etc. The industrial robot of this embodiment adopts the harmonic reducer 1000 of the above embodiment. The harmonic reducer 1000 is provided with an oil seal 600 to seal the second gap 412 on the outer side of the raceway 440 of the support bearing 400, and a sealing member 500 to seal the first gap 411 on the side of the raceway 440 near the diaphragm 120 of the flexure 100. The sealing member 500 includes a first sealing part 510 and a second sealing part 520 connected to each other. The first sealing part 510 extends axially along the flexure 100 and abuts against the inner side of the outer ring 420 of the support bearing 400. The second sealing part 520 extends radially along the flexure 100 and abuts against the end face of the inner ring 410 facing the diaphragm 120, forming a two-stage seal. Under the combined action of the sealing member 500 and the oil seal 600, the sealing performance of the harmonic reducer 1000 is greatly improved, effectively suppressing the leakage of lubricant.

[0049] The industrial robot of this invention adopts all the technical solutions of the harmonic reducer 1000 of the above embodiments, and therefore has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0050] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A harmonic reducer, characterized in that, include: The flexible wheel includes a cylindrical portion, a diaphragm portion, and a flange portion. One end of the cylindrical portion has an external toothed portion on its outer side. The diaphragm portion is connected to the other end of the cylindrical portion and extends radially outward along the cylindrical portion. The flange portion is connected to the end of the diaphragm portion away from the cylindrical portion. The rigid wheel has an inner hole arranged around the outer side of the cylindrical part, and the wall of the inner hole has an internal toothed part; A wave generator is installed on the inner side of the cylindrical portion, and the wave generator is configured to partially engage the outer tooth portion with the inner tooth portion; A support bearing is configured to enable the flexible wheel and the rigid wheel to rotate relative to each other. The support bearing includes an inner ring, an outer ring, and rolling elements installed in a raceway formed between the inner ring and the outer ring. The inner ring is fixedly connected to the rigid wheel, and the outer ring is fixedly connected to the flange. A first gap exists between the inner ring and the diaphragm. A second gap exists between the outer side of the inner ring away from the diaphragm and the corresponding position of the inner side of the outer ring. The first gap and the second gap are located at the two ends of the raceway, respectively. A sealing element for sealing the first gap, the sealing element comprising a first sealing portion and a second sealing portion connected together, the first sealing portion extending axially along the flexible wheel and abutting against the inner side of the outer ring, the second sealing portion extending radially along the flexible wheel and inserted into the first gap, the second sealing portion abutting against the end face of the inner ring facing the diaphragm. An oil seal is used to seal the second gap.

2. The harmonic reducer according to claim 1, characterized in that: The flange includes a thickened region that protrudes inward from the inner side of the outer ring, and the second sealing portion also abuts against one end of the thickened region facing the inner ring.

3. The harmonic reducer according to claim 1 or 2, characterized in that: The seal further includes a third sealing portion connected to the second sealing portion. The third sealing portion extends axially along the flexible wheel and is inserted into a third gap between the inner ring and the cylindrical portion. The third sealing portion abuts against the side of the inner ring facing the cylindrical portion.

4. The harmonic reducer according to claim 3, characterized in that: The sealing element is annular; The first sealing portion includes a first protrusion abutting against the inner side surface of the outer ring, the first protrusion being annular and having a cross-sectional width that gradually decreases towards the abutting surface; and / or, The second sealing portion includes a second protrusion abutting against the end face of the inner ring facing the diaphragm, the second protrusion being annular and the width of its cross-section gradually decreasing towards the abutting surface; and / or, The third sealing portion includes a third protrusion that abuts against the side of the inner ring facing the cylindrical portion. The third protrusion is annular and the width of its cross-section gradually decreases in the direction of the abutment surface.

5. The harmonic reducer according to claim 1, characterized in that: The seal includes a retainer and a sealing body. The retainer includes a first inner ring and a second inner ring connected to each other. The sealing body wraps around at least a portion of the first inner ring and at least a portion of the second inner ring. The first inner ring abuts against the inner side of the outer ring through the sealing body, and the second inner ring abuts against the end face of the inner ring facing the diaphragm through the sealing body.

6. The harmonic reducer according to claim 5, characterized in that: The retainer further includes a third ring body connected to the second inner ring body, and the seal body also wraps around at least a portion of the third ring body, the third ring body abutting against the side of the inner ring facing the cylindrical portion via the seal body.

7. The harmonic reducer according to claim 5, characterized in that: The sealing body is wrapped around the outside of the retainer, and the material of the sealing body is an elastic sealing material.

8. The harmonic reducer according to claim 1, characterized in that: The inner ring includes a first annular body and a second annular body that are fixedly connected. The first annular body is located at one end near the diaphragm, and the second annular body is located at one end near the rigid wheel and is fixedly connected to the rigid wheel. The first annular body and the second annular body are fixedly connected by a first screw.

9. The harmonic reducer according to claim 8, characterized in that: The second sealing portion includes a second protrusion abutting against the end face of the inner ring facing the diaphragm, and the second protrusion and the first screw are arranged radially spaced along the flexible wheel.

10. The harmonic reducer according to claim 8, characterized in that: The seal further includes a third sealing portion connected to the second sealing portion. The third sealing portion includes a third protrusion abutting against the side of the inner ring facing the cylindrical portion. The third protrusion abuts against the first annular body and / or the second annular body.

11. The harmonic reducer according to claim 1, characterized in that: The outer ring includes a second mounting portion and a protrusion connected to the inner side of the second mounting portion. The protrusion has a first outer raceway and a second outer raceway that are opposite to each other at both ends along the axial direction. The outer side of the inner ring is provided with a groove that is opposite to the protrusion, and the two ends of the groove along the axial direction are respectively provided with a first inner raceway and a second inner raceway. The rolling element includes a first steel ball and a second steel ball; The first inner raceway and the first outer raceway are arranged opposite to each other and form a first groove for receiving the first steel ball, and the second inner raceway and the second outer raceway are arranged opposite to each other and form a second groove for receiving the second steel ball.

12. An industrial robot, characterized in that: Includes the harmonic reducer as described in any one of claims 1 to 11.

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