Workpiece and speed reducer

Abstract

The invention discloses a workpiece and a speed reducer, and relates to the technical field of workpiece machining. The convex part and the concave part are arranged on the hole wall of the corresponding position of the center hole of the workpiece, when the clamp clamps the workpiece, the tensioning part is arranged in the center hole in a penetrating mode, the side wall of the tensioning part abuts against the convex part, and the effect of limiting the position of the workpiece can be achieved. Due to the fact that the protruding part is located in the first area of the center hole, under the partition of the through hole, pressure generated by the clamp is difficult to transmit to the outer wall face of the workpiece when the tensioning part abuts against the protruding part. And when the tensioning part and the concave part are arranged at intervals, the pressure generated by the clamp can be prevented from being transmitted to the workpiece through the concave part, so that the fluctuation uniformity of the outer wall surface when the cycloidal gear is clamped is ensured, and the machining precision of the workpiece is improved.

Description

Technical Field

[0001] This invention relates to the field of workpiece processing technology, and in particular to a workpiece and a speed reducer. Background Technology

[0002] When machining the external gear section of the cycloidal gear in an RV reducer, an internal expansion clamp is required to hold and position the cycloidal gear. For example, the clamp includes a tensioning part that engages with the center hole of the cycloidal gear. The tensioning part expands to clamp the cycloidal gear. The pressure generated by the clamp is usually transmitted to the outer wall surface of the cycloidal gear, causing a certain degree of elastic deformation. Since the cycloidal gear also has crankshaft holes and other irregularly shaped holes, the pressure generated by the clamp is difficult to transmit to the outer wall surface of the cycloidal gear through these holes, resulting in uneven deformation of the outer wall surface. After the external gear section of the cycloidal gear is machined and the clamp is released, the elastic deformation of the outer wall surface rebounds, increasing the radial runout and tooth pitch error of the cycloidal gear, thus affecting the stability of the RV reducer during operation. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a workpiece that can improve the situation of uneven deformation during the clamping process of a fixture, thereby improving machining accuracy.

[0004] The present invention also proposes a speed reducer having the above-mentioned workpiece.

[0005] According to a first aspect of the present invention, the workpiece has an outer peripheral wall as a bearing portion, the workpiece has a central hole and a plurality of through holes spaced apart around the central hole, and along the circumference of the central hole, the region where the maximum central angle of each through hole corresponds to the center of the central hole is located is a first region, the hole wall of the central hole is provided with a protrusion in the first region, and a concave portion is formed between two adjacent protrusions.

[0006] The workpiece according to the embodiments of the present invention has at least the following beneficial effects: By providing protrusions and recesses on the wall of the workpiece's central hole at corresponding positions, when the fixture clamps the workpiece to machine the bearing portion, the tensioning part passes through the central hole, and the side wall of the tensioning part abuts against the protrusion, thus restricting the workpiece's position. Since the protrusion is located in the first region of the central hole, the pressure generated by the fixture is difficult to transmit to the outer wall surface of the workpiece when the tensioning part and the protrusion abut against each other due to the through-hole's obstruction. Furthermore, when the tensioning part and the recess are spaced apart, the pressure generated by the fixture is prevented from being transmitted to the workpiece through the recess, thereby ensuring the uniformity of the outer wall surface undulation when the cycloidal wheel is clamped, and improving the workpiece's machining accuracy.

[0007] According to some embodiments of the present invention, the maximum depth of the recess along the radial direction of the central hole is H, satisfying H≥0.01mm.

[0008] According to some embodiments of the present invention, the workpiece is a cycloidal wheel, the through hole is an irregularly shaped hole through which the support column of the planetary carrier passes, and the bearing portion is configured as an annular external toothed portion.

[0009] According to some embodiments of the present invention, the cycloidal wheel is further provided with a plurality of crankshaft holes for the crankshaft to pass through. The crankshaft holes are located between at least partially adjacent irregular holes. Along the circumference of the central hole, the area where the maximum central angle of each crankshaft hole corresponds to the center of the central hole is located is a second region. A recess is provided in the second region along the circumference of the central hole, and both ends of the recess are located outside the second region.

[0010] According to some embodiments of the present invention, the minimum distance between the irregular hole and the central hole along the radial direction of the central hole is less than the minimum distance between the crankshaft hole and the central hole; and / or, on a projection plane perpendicular to the axis of the central hole, the opening area of ​​the crankshaft hole is less than the opening area of ​​the irregular hole.

[0011] According to some embodiments of the present invention, the workpiece is a cycloidal wheel, the bearing portion is configured as an annular external tooth portion, the through hole is a crankshaft hole for the crankshaft to pass through, an irregular hole is provided between adjacent crankshaft holes, and along the circumference of the central hole, the region where the maximum central angle corresponding to the center of the central hole is located between every two adjacent crankshaft holes is a third region, and at least a portion of the structure of one of the recesses is located within a corresponding third region.

[0012] According to some embodiments of the present invention, the minimum distance between the crankshaft hole and the central hole along the radial direction of the central hole is less than the minimum distance between the irregular hole and the central hole; and / or, on a projection plane perpendicular to the axis of the central hole, the opening area of ​​the irregular hole is less than the opening area of ​​the crankshaft hole.

[0013] According to some embodiments of the present invention, the workpiece is a cycloidal wheel, the bearing portion is configured as an annular external tooth portion, the through hole is a first mounting hole for the support column of the planetary carrier to pass through, three first mounting holes arranged sequentially along the circumference of the central hole constitute a hole group, the hole group is provided with two groups spaced apart, a crankshaft hole is provided between adjacent hole groups, along the circumference of the central hole, the area where the maximum central angle corresponding to the center of the central hole is located between adjacent hole groups is a fourth region, and at least a portion of the structure of one of the recesses is located in a corresponding fourth region.

[0014] According to some embodiments of the present invention, along the radial direction of the central hole, the minimum distance between the first mounting hole and the central hole is less than the minimum distance between the crankshaft hole and the central hole; and / or, on a projection plane perpendicular to the axis of the central hole, the opening area of ​​the crankshaft hole is less than the opening area of ​​the first mounting hole.

[0015] According to some embodiments of the present invention, the workpiece is a flange, the bearing portion is configured as an annular first outer raceway, the through hole is a first mating hole, and a plurality of first mating holes are evenly spaced along the circumference of the central hole; or, the workpiece is a planetary carrier, the bearing portion is configured as an annular second outer raceway, the through hole is a second mating hole for the crankshaft to pass through, and a plurality of second mating holes are evenly spaced along the circumference of the central hole.

[0016] According to some embodiments of the present invention, the central hole has a symmetrical structure on a projection plane perpendicular to the axis of the central hole.

[0017] According to a second aspect of the present invention, the workpiece has a central hole and a plurality of through holes spaced apart around the central hole. Along the circumference of the central hole, the region where the maximum central angle of the through holes corresponds to the center of the central hole is located is a fifth region. The outer wall surface of the workpiece is provided with a protrusion in the fifth region, and a concave portion is formed between two adjacent protrusions.

[0018] The workpiece according to the embodiments of the present invention has at least the following beneficial effects: By setting protrusions and recesses at corresponding positions on the outer wall of the workpiece, when the fixture clamps the workpiece, the tensioning part is fitted onto the outer wall of the workpiece, and the side wall of the tensioning part abuts against the protrusion, which can restrict the position of the workpiece. Since the protrusion is located in the fifth region of the central hole, the pressure generated by the fixture is difficult to be transmitted to the outer wall of the workpiece when the tensioning part and the protrusion abut against each other due to the obstruction of the through hole; and when the tensioning part and the recess are set alternately, the pressure generated by the fixture can be prevented from being transmitted to the workpiece through the recess, thereby ensuring the uniformity of the inner wall surface undulation when the workpiece is clamped, reducing the machining error of the workpiece, improving the machining accuracy of the workpiece, and thus extending the durability of the workpiece.

[0019] According to some embodiments of the present invention, the workpiece is a rigid wheel, the bearing portion is configured as an annular internal tooth portion, and the through hole is a second mounting hole for fasteners to pass through.

[0020] The speed reducer according to a third aspect of the present invention includes the workpiece described in the above embodiments.

[0021] The speed reducer according to embodiments of the present invention has at least the following beneficial effects: By employing the workpiece of the first aspect embodiment, and by providing a protrusion and a recess on the wall of the hole corresponding to the center hole of the workpiece, when the fixture clamps the workpiece to process the bearing portion, the tensioning part passes through the center hole, and the side wall of the tensioning part abuts against the protrusion, which can restrict the position of the workpiece. Since the protrusion is located in the first region of the center hole, it is difficult to transmit the pressure generated by the fixture to the outer wall surface of the workpiece when the tensioning part and the protrusion abut against each other due to the obstruction of the through hole; and when the tensioning part and the recess are spaced apart, the pressure generated by the fixture can be prevented from being transmitted to the workpiece through the recess, thereby ensuring the uniformity of the undulation of the outer wall surface when the cycloidal wheel is clamped, so as to improve the machining accuracy of the workpiece.

[0022] 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

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a cross-sectional view of an RV reducer according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a clamp holding a cycloidal wheel according to an embodiment of the present invention; Figure 3 This is an exploded view of a clamp and cycloidal wheel according to an embodiment of the present invention; Figure 4 This is a cross-sectional view of a clamp and cycloidal wheel according to an embodiment of the present invention; Figure 5 This is a top view of the cycloidal wheel according to the first embodiment of the present invention; Figure 6 This is a top view of the cycloidal wheel according to the second embodiment of the present invention; Figure 7 This is a top view of the cycloidal wheel according to the third embodiment of the present invention; Figure 8 This is a top view of a flange according to an embodiment of the present invention; Figure 9 This is a top view of the planetary carrier structure according to an embodiment of the present invention; Figure 10 This is a top view of a rigid wheel according to an embodiment of the present invention; Figure 11 This is a schematic diagram of the radial runout of the cycloidal wheel in one embodiment of the present invention when no protrusions and recesses are provided; Figure 12 This is a schematic diagram of radial runout when the cycloidal wheel of an embodiment of the present invention has a convex part and a concave part.

[0024] Figure label: Workpiece 100; Center hole 110; Protrusion 111; Recess 112; First end 1121; Second end 1122; Through hole 120; First region 130; Second region 140; Third region 150; Fourth region 160; Clamp 200; tensioning part 210; main body 211; liquid inlet channel 212; liquid storage tank 213; flexible ring 214; first positioning block 220; second positioning block 230; support part 240; clamping part 250; fastener 260; RV reducer 300; cycloidal wheel 310; irregular hole 311; crankshaft hole 312; first mounting hole 313; hole group 314; crankshaft 320; pin gear housing 330; planetary carrier 340; second mating hole 341; support column 342; flange 350; first mating hole 351; Rigid wheel 400; second mounting hole 410; fifth zone 420. Detailed Implementation

[0025] 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.

[0026] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying 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.

[0027] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0028] 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.

[0029] Reference Figure 1As shown, the workpiece 100 in one embodiment of the present invention can be a cycloidal wheel 310, flange 350, and planetary carrier 340 used in an RV reducer 300; or it can be a cycloidal wheel 310 used in a cycloidal reducer. The outer peripheral wall of the workpiece 100 is a bearing portion, and the bearing portion can only be machined after the workpiece 100 is clamped by the fixture 200. For example, when the workpiece 100 is a cycloidal wheel 310, the outer tooth portion of the cycloidal wheel 310 is machined; when the workpiece 100 is a flange 350, planetary carrier 340, or pin tooth housing 330, the first outer raceway of the flange 350, the second outer raceway of the planetary carrier 340, or the inner raceway of the pin tooth housing 330 is machined. Therefore, depending on the type of workpiece 100, the bearing portion can be an annular outer tooth portion, an annular outer raceway, an annular inner raceway, an annular inner tooth portion, etc.

[0030] Workpiece 100 needs to be clamped by fixture 200 during processing, as shown in the reference. Figure 2 and Figure 3 As shown, the clamp 200 includes a tensioning part 210, a first positioning block 220, a second positioning block 230, a support part 240, a clamping part 250, and a fastener 260. The tensioning part 210 is connected to the upper end of the support part 240, and the clamping part 250 is connected to the upper end of the tensioning part 210 and can be limited by the fastener 260. A clamping space for clamping the workpiece 100 is formed between the clamping part 250 and the support part 240. The first positioning block 220 and the second positioning block 230 are disposed on the upper end face of the support part 240. The workpiece 100 has a central hole 110 and a plurality of through holes 120, which are spaced apart around the axis of the central hole 110. Unless otherwise specified, for ease of explanation, the workpiece 100 is described as a cycloidal wheel 310 in the following embodiments, and the bearing part is configured as an annular external toothed part. When clamping the cycloidal wheel 310, the tensioning part 210 passes through the central hole 110 of the workpiece 100, the support part 240 supports the workpiece 100, and the clamping part 250 abuts against the upper end face of the workpiece 100 to limit the axial displacement of the workpiece 100. The first positioning block 220 and the second positioning block 230 are positioned and engaged with the through hole 120 to determine the relative position of the cycloidal wheel 310 and the fixture. The outer diameter of the tensioning part 210 can expand to abut against the wall of the central hole 110 to limit the radial displacement of the workpiece 100.

[0031] Reference Figure 4As shown, the principle behind the expansion and deformation of the tensioning part 210 is as follows: The tensioning part 210 includes a main body 211 and a flexible ring 214. The main body 211 has an inlet channel 212, and a reservoir 213 surrounds the outer wall of the main body 211. The flexible ring 214 is fixedly connected to the outer wall of the main body 211 and closes the opening of the reservoir 213. A reservoir space communicating with the inlet channel 212 is formed between the flexible ring 214 and the reservoir 213. For example, the reservoir space can store hydraulic oil. It is understood that a pressure screw or piston can be installed in the inlet channel 212. Taking the pressure screw as an example, pushing the pressure screw reduces the volume of the inlet channel 212, allowing hydraulic oil to flow into the reservoir 213. Because the flexible ring 214 can undergo elastic deformation, it expands under the pressure of the hydraulic oil, thereby increasing its outer diameter and engaging with the wall of the central hole 110 to limit the radial position of the cycloidal wheel 310.

[0032] When the tensioning part 210 is tensioned, it transmits pressure to the outer wall surface of the cycloidal wheel 310, causing it to bulge. Because the cycloidal wheel 310 has multiple through holes 120 around its central hole 110, these through holes act as barriers, making it difficult for the pressure from the clamp 200 to be effectively transmitted to the outer wall surface of the cycloidal wheel 310. This results in uneven deformation of the outer wall surface of the cycloidal wheel 310. After machining the external teeth and releasing the clamp 200, the outer wall surface of the cycloidal wheel 310 springs back, causing uneven deformation of the machined external teeth, increasing radial runout and tooth pitch error.

[0033] To improve the situation of uneven deformation during clamping by fixture 200, refer to Figure 5 As shown, in an embodiment of the present invention, along the circumference of the central hole 110, the region where the maximum central angle of the through hole 120 corresponds to the center of the central hole 110 is located is the first region 130, for example... Figure 5 The area enclosed between the two dotted lines with an angle of α is the first region 130. The wall of the central hole 110 has a protrusion 111 within the first region 130; that is, the through hole 120 is provided with a protrusion 111 corresponding to the wall of the central hole 110, and a recess 112 is formed between two adjacent protrusions 111. When the clamp 200 clamps the cycloidal wheel 310, the tensioning part 210 passes through the central hole 110, and the side wall of the tensioning part 210 abuts against the protrusion 111, while the side wall of the tensioning part 210 and the recess 112 are spaced apart. It should be noted that the protrusion 111 within the first region 130 can be completely located within the first region 130, or both ends of the protrusion 111 along the circumferential direction can coincide with the edge of the first region 130, or one end of the protrusion 111 along the circumferential direction can coincide with the edge of the first region 130, while the other end of the protrusion 111 is located within the first region 130. It should also be noted that, for ease of illustration, the positional relationship between the protrusion 111 and the recess 112 is not shown. Figure 5 The depth of the concave portion 112 has been increased to some extent for ease of understanding. The accompanying drawings are merely illustrative and do not represent a fixed proportional relationship in the actual product. The concave portions 112 and convex portions 111 in other drawings are similar and will not be described further.

[0034] Understandably, by adopting the above solution, since the protrusion 111 is located in the first region 130 of the central hole 110, under the obstruction of the through hole 120, it is difficult for the tensioning part 210 and the protrusion 111 to transmit the pressure generated by the clamp 200 to the outer wall surface of the cycloidal wheel 310 when they abut against each other. Moreover, when the tensioning part 210 and the recess 112 are spaced apart, the pressure generated by the clamp 200 can be prevented from being transmitted to the cycloidal wheel 310 through the recess 112, thereby ensuring the uniformity of the undulation of the outer wall surface of the cycloidal wheel 310 when it is clamped, reducing the radial runout and pitch error of the outer teeth of the cycloidal wheel 310, thereby improving the machining accuracy of the cycloidal wheel 310, extending the durability of the cycloidal wheel 310 and improving the stability of the torsional rigidity of the RV reducer.

[0035] For specific effects, please refer to... Figure 11 and Figure 12 As shown, Figure 11 This refers to the radial runout of the cycloidal wheel 310 when the protrusion 111 and the recess 112 are not provided. Figure 12 A schematic diagram of radial runout when the cycloidal wheel 310 has a protrusion 111 and a recess 112. Figure 11 and Figure 12 The horizontal axis represents different positions of the outer wall of the cycloidal wheel 310 along its circumference, and the vertical axis represents the magnitude of the radial runout. Radial runout is defined as the fluctuation in distance between the center of a measuring ball of a certain diameter and the center of the cycloidal wheel 310 when the ball contacts the tooth surface of each tooth groove on the outer tooth section of the cycloidal wheel 310. A positive radial runout indicates that the outer tooth at that point is far from the center of the cycloidal wheel 310. A negative radial runout indicates that the outer tooth at that point is close to the center of the cycloidal wheel 310.

[0036] Therefore from Figure 11 As can be seen, without the protrusion 111 and the recess 112, the radial runout of the cycloidal wheel 310 is more pronounced and exhibits periodic variations. This is because the obstruction of the through hole 120 prevents the pressure generated by the clamp 200 from being transmitted to the outer wall of the cycloidal wheel 310. Therefore, the more pronounced radial runout is related to the positional distribution of the through hole 120. From... Figure 12 As can be seen from the diagram, when the protrusion 111 and the concave portion 112 are provided, the radial runout of the cycloidal wheel 310 is significantly reduced, and the runout value is small, indicating that providing the protrusion 111 and the concave portion 112 can effectively improve the machining accuracy of the external teeth of the cycloidal wheel 310.

[0037] It should be noted that when the center hole 110 does not need to mate with other parts, or when the protrusion 111 and concave portion 112 do not affect the stability of the mating, the final machined cycloidal wheel 310 can retain the features of the protrusion 111 and concave portion 112. When the concave portion 112 and protrusion 111 affect the mating effect of the cycloidal wheel 310 with other parts, after the external teeth of the cycloidal wheel 310 are machined, the protrusion 111 can be removed by turning, so that the hole wall of the center hole 110 is constructed as a complete arc surface. The appropriate machining method should be selected according to the actual situation.

[0038] Reference Figure 5 As shown, in an embodiment of the present invention, the maximum depth of the recess 112 along the radial direction of the central hole 110 is H, satisfying: H ≥ 0.01 mm. For example, the value of H can be 0.01 mm, 0.02 mm, 0.04 mm, 0.05 mm, 0.1 mm, etc. H can be the difference between the radius of the arc surface of the protrusion 111 and the radius of the arc surface of the recess 112. It should be noted that the wall of the central hole 110 is provided with multiple recesses 112, and the maximum depth of different recesses 112 can be the same or different. When H is less than 0.01 mm, that is, the depth of the recess 112 is shallow, the tensioning part 210 will expand and deform to a certain extent, which may cause the tensioning part 210 and the wall surface of the recess 112 to abut, thereby transmitting pressure to the cycloidal wheel 310, causing uneven deformation of the outer wall surface of the cycloidal wheel 310, resulting in a reduction in the machining accuracy of the outer teeth of the cycloidal wheel 310. Therefore, by setting H to be greater than or equal to 0.01 mm, the tensioning part 210 and the recess 112 can be prevented from abutting each other, ensuring that the tensioning part 210 and the recess 112 are spaced apart, so as to ensure the uniformity of the undulation of the outer wall surface when the cycloidal wheel 310 is clamped and improve the machining accuracy of the cycloidal wheel 310.

[0039] Continue to refer to Figure 5As shown, in the first embodiment of the present invention, the through hole 120 is a shaped hole 311, which is used for the support column 342 of the planetary carrier 340 to pass through. It is understood that since the RV reducer 300 generally has two cycloidal wheels 310, which oscillate back and forth under the drive of the crankshaft 320, a single cycloidal wheel 310 would cause the RV reducer 300 to run unevenly. Therefore, two cycloidal wheels 310 are required, with a phase difference of 180 degrees between them. This helps to counteract the radial runout during the movement of the cycloidal wheels 310, thereby significantly improving the stability of the RV reducer 300. To ensure that the two cycloidal wheels 310 have a specific phase difference, multiple irregular holes 311 are provided on the cycloidal wheels 310. The multiple irregular holes 311 cooperate with the support column 342 of the planet carrier 340. After one cycloidal wheel 310 rotates 180 degrees relative to the other cycloidal wheel 310 and then cooperates with the support part 240, it can be ensured that the two cycloidal wheels 310 maintain a phase difference of 180 degrees.

[0040] Continue to refer to Figure 5 As shown, in an embodiment of the present invention, the cycloidal wheel 310 is further provided with a crankshaft hole 312, which is used to cooperate with the crankshaft 320. When the crankshaft 320 rotates, it can drive the cycloidal wheel 310 to oscillate. The crankshaft hole 312 is provided between at least some of the adjacent irregular holes 311. For example, a crankshaft hole 312 may be provided between every two adjacent irregular holes 311; or a crankshaft hole 312 may be provided between every other irregular hole 311 and the next adjacent irregular hole 311. Along the circumference of the central hole 110, the region where the maximum central angle of each crankshaft hole 312 corresponds to the center of the central hole 110 is the second region 140. Along the circumference of the central hole 110, a recess 112 passes through the second region 140, and the two ends of the recess 112 are respectively located outside the second region. For example... Figure 5 As shown, the two ends of the recess 112 along the circumferential direction are a first end 1121 and a second end 1122, which are located outside the second region 140.

[0041] It should be noted that the distance between the crankshaft bore 312 and the center bore 110, as well as the opening area of ​​the crankshaft bore 312, both affect the force transmission. The greater the distance between the crankshaft bore 312 and the center bore 110, the greater the impact on the protrusion of the outer wall of the cycloidal wheel 310 when the wall of the center bore 110 abuts against the clamp. Conversely, the smaller the opening area of ​​the crankshaft bore 312, the greater the impact on the protrusion of the outer wall of the cycloidal wheel 310 when the wall of the center bore 110 abuts against the clamp. The same principle applies to other bores, and the reasons will not be elaborated further.

[0042] In embodiments of the present invention, the minimum distance between the irregular hole 311 and the central hole 110 along the radial direction of the central hole 110 is less than the minimum distance between the crankshaft hole 312 and the central hole 110; on the projection plane perpendicular to the axis of the central hole 110, the opening area of ​​the irregular hole 311 is less than the opening area of ​​the crankshaft hole 312. Therefore, since the distance between the crankshaft hole 312 and the central hole 110 in this embodiment is relatively large, if the tensioning part 210 and the hole wall of the central hole 110 corresponding to the crankshaft hole 312 abut against each other, it is easy for the pressure of the clamp 200 to be transmitted to the outer wall surface of the cycloidal wheel 310. Therefore, the hole wall of the central hole 110 corresponding to the crankshaft hole 312 is also set as a recess 112 to ensure the uniformity of the undulation of the outer wall surface when the cycloidal wheel 310 is clamped.

[0043] It should be noted that, depending on the size of the crankshaft hole 312 and its distance from the center hole 110, the hole wall of the center hole 110 corresponding to the crankshaft hole 312 can also be set as a recess 112. The specific design of the structure of the center hole 110 is based on whether it will cause a large degree of uneven deformation of the outer wall of the cycloidal wheel 310.

[0044] Continue to refer to Figure 5 As shown, in this embodiment of the invention, there are six irregularly shaped holes 311, arranged in pairs, for a total of three groups of irregularly shaped holes 311. These three groups are evenly spaced along the circumference of the central hole 110. Three crankshaft holes 312 are provided, with one crankshaft hole 312 between each group of irregularly shaped holes 311, and these crankshaft holes 312 are also evenly spaced along the circumference of the central hole 110. It is understood that by adopting the above scheme, the uniformity of the distribution of the protrusions 111 and concave portions 112 can be ensured. For example, on a projection plane perpendicular to the axis of the central hole 110, the central hole 110 has a symmetrical structure. Therefore, when the tensioning part 210 clamps the cycloidal wheel 310, it reduces the uneven force distribution on the cycloidal wheel 310. It should be noted that the irregular hole 311 and the crankshaft hole 312 can also be in other quantities. For example, the number of irregular holes 311 can be two, three, four, or five, and the number of crankshaft holes 312 can be two, four, or five, etc. The appropriate solution should be selected according to the actual situation.

[0045] Reference Figure 6As shown, in the second embodiment of the present invention, the structure of the cycloidal wheel 310 in this embodiment is similar to that of the cycloidal wheel 310 in the above embodiment. The difference is that the through hole 120 of the cycloidal wheel 310 in this embodiment is a crankshaft hole 312 for the crankshaft 320 to pass through. A shaped hole 311 is provided between adjacent crankshaft holes 312, and the crankshaft hole 312 is closer to the central hole 110 than the shaped hole 311. For example, there are three crankshaft holes 312 and three shaped holes 311, and the three crankshaft holes 312 and three shaped holes 311 are arranged alternately and evenly along the circumference of the central hole 110. Of course, the number of crankshaft holes 312 and shaped holes 311 can also be two, four, etc., depending on the actual situation. Along the circumference of the central hole 110, the region where the maximum central angle between two adjacent crankshaft holes 312 corresponds to the center of the central hole 110 is the third region 150, such as... Figure 6 The area enclosed by the two dashed lines is the third region 150, and at least a portion of the structure of one of the recesses 112 is located within the corresponding third region 150. The definition of the first region 130 is similar to that in the above embodiment, and will not be repeated here. It should be noted that the fact that at least a portion of the structure of one of the recesses 112 is located within the corresponding third region 150 can mean that the recess 112 is completely located within the third region 150, or that a portion of the structure of the recess 112 is located within the third region 150, while both ends of the recess 112 protrude out of the third region 150; or that one end of the recess 112 is located within the third region 150, and the other end protrudes out of the third region 150.

[0046] Understandably, since the crankshaft bore 312 is closer to the center bore 110 than the irregular bore 311, when the tensioning part 210 abuts against the wall of the center bore 110 corresponding to the irregular bore 311, the pressure of the tensioning part 210 is easily transmitted to the outer wall surface around the irregular bore 311. Furthermore, the crankshaft bore 312 has a larger diameter; therefore, a protrusion 111 is provided at the wall of the crankshaft bore 312 corresponding to the center bore 110, and a recess 112 is provided at other locations. With the separation provided by the crankshaft bore 312 and the recess 112, it is difficult for the tensioning part 210 and the protrusion 111 to transmit the pressure generated by the fixture 200 to the outer wall surface of the cycloidal wheel 310 when they abut. This reduces the radial runout and pitch error of the outer teeth of the cycloidal wheel 310, thereby improving the machining accuracy of the cycloidal wheel 310, extending its durability, and improving the stability of the torsional rigidity of the RV reducer.

[0047] Reference Figure 7As shown, in the third embodiment of the present invention, the structure of the cycloidal wheel 310 in this embodiment is similar to that of the cycloidal wheel 310 in the above embodiments. The difference is that the through hole 120 of the cycloidal wheel 310 in this embodiment is a first mounting hole 313 for the support column 342 of the planetary carrier 340 to pass through. The first mounting hole 313 is a circular hole. Three first mounting holes 313 arranged sequentially along the circumference of the central hole 110 constitute a hole group 314. The hole group 314 is provided with two groups at intervals. A crankshaft hole 312 is provided between the two ends of adjacent hole groups 314, that is, there are two crankshaft holes 312. The first mounting holes 313 are closer to the central hole 110 than the crankshaft holes 312. Along the circumference of the central hole 110, the region where the maximum central angle of the center of the central hole 110 is located between adjacent hole groups 314 is the fourth region 160, such as... Figure 7 The area enclosed by the two dashed lines is the fourth region 160. At least a portion of the structure of one of the recesses 112 is located within a corresponding fourth region 160. It should be noted that the recess 112 within the fourth region 160 can be completely located within the fourth region 160; it can also be partially located within the fourth region 160, with both ends of the recess 112 protruding out of the fourth region 160; or it can be that one end of the recess 112 is located within the fourth region 160, and the other end of the recess 112 protrudes out of the fourth region 160.

[0048] Understandably, since the first mounting hole 313 is closer to the center hole 110 than the crankshaft hole 312, when the tensioning part 210 abuts against the wall of the center hole 110 corresponding to the crankshaft hole 312, the pressure of the tensioning part 210 is easily transmitted to the outer wall surface around the crankshaft hole 312. Furthermore, the diameter of the first mounting hole 313 is relatively large. Therefore, a protrusion 111 is provided at the wall of the center hole 110 corresponding to the first mounting hole 313, and a recess 112 is provided at other locations. Simply put, recesses 112 are provided on the walls of the corresponding center holes 110 between adjacent first mounting holes 313. With the separation between the first mounting hole 313 and the recess 112, when the tensioning part 210 and the protrusion 111 abut, it is difficult to transmit the pressure generated by the clamp 200 to the outer wall surface of the cycloidal wheel 310. This can reduce the radial runout and pitch error of the outer teeth of the cycloidal wheel 310, thereby improving the machining accuracy of the cycloidal wheel 310, extending the durability of the cycloidal wheel 310 and improving the stability of the torsional rigidity of the RV reducer.

[0049] Reference Figure 8As shown, in this embodiment of the invention, the workpiece 100 is a flange 350, and the bearing portion is configured as an annular first outer raceway. The through hole 120 is a first mating hole 351, and multiple first mating holes 351 are evenly spaced along the circumference of the central hole 110. For example, there may be three first mating holes 351, evenly spaced along the circumference of the central hole 110. Of course, the number of first mating holes 351 can also be other, such as two or four, depending on the actual situation. The first mating holes 351 are used to mate with the crankshaft 320 of the RV reducer 300. One end of the crankshaft 320 is fitted with a bearing, which is embedded in the first mating hole 351, ensuring that the crankshaft 320 can rotate smoothly. Because the first mating holes 351 are evenly spaced, it is beneficial to evenly arrange the protrusions 111 and concave portions 112. Therefore, when the tensioning portion 210 clamps the flange 350, it can reduce uneven force on the flange 350, thereby improving the machining accuracy of the first outer raceway.

[0050] It should be noted that when the center hole 110 of the flange 350 needs to mate with other parts, the center hole 110 of the flange 350 can be machined to remove the protrusion 111, so that the center hole 110 of the flange 350 is constructed as a complete arc surface. When the protrusion 111 and the recess 112 do not affect the mating effect of the flange 350 with other parts, the protrusion 111 and the recess 112 can also be retained.

[0051] Reference Figure 9 As shown, in this embodiment of the invention, the workpiece 100 is a planetary carrier 340, and the supporting part is configured as an annular second outer raceway. The through hole 120 is a second mating hole 341, and a plurality of second mating holes 341 are evenly spaced along the circumference of the central hole 110. For example, there are three second mating holes 341, which are evenly spaced along the circumference of the central hole 110. Of course, the number of second mating holes 341 can also be other, such as two, four, etc., and the appropriate number is selected according to the actual situation. The second mating holes 341 are used to mate with the crankshaft 320 of the RV reducer 300. For example, the crankshaft 320 passes through the second mating holes 341 to ensure that the crankshaft 320 can rotate smoothly. Since the second mating holes 341 are evenly spaced, it is beneficial to evenly arrange the protrusions 111 and the recesses 112. Therefore, when the tensioning part 210 clamps the planetary carrier 340, it can reduce the uneven force on the planetary carrier 340, thereby improving the machining accuracy of the second outer raceway.

[0052] It should be noted that when the center hole 110 of the planetary carrier 340 needs to mate with other parts, the center hole 110 of the planetary carrier 340 can be machined to remove the protrusion 111, so that the center hole 110 of the planetary carrier 340 is constructed as a complete arc surface. When the protrusion 111 and the recess 112 do not affect the mating effect of the planetary carrier 340 with other parts, the protrusion 111 and the recess 112 can also be retained.

[0053] Reference Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown in the embodiment of the present invention, the central hole 110 has a symmetrical structure on the projection plane perpendicular to the axis of the central hole 110. It should be noted that the protrusion 111 and the recess 112 belong to the structure of the central hole 110. It can be understood that the protrusion 111 is the main stress-bearing part of the workpiece 100. In order to ensure the uniformity of the stress on the workpiece 100, the central hole 110 is designed as a symmetrical structure. By reasonably designing the position of the protrusion 111, for example, multiple protrusions 111 are evenly spaced along the circumference of the central hole 110, or every two or three protrusions 111 are grouped together, and each group of protrusions 111 is evenly spaced, it can be ensured that the workpiece 100 is subjected to uniform stress when the fixture 200 clamps the workpiece 100, thereby improving the machining accuracy of the workpiece 100.

[0054] For some workpieces 100 that require machining of their inner wall surfaces, such as machining the internal teeth of a rigid wheel 400, or machining the internal teeth or internal raceways of a pin tooth housing 330, a fixture 200 is needed to hold the outer wall surface of the workpiece 100. The workpiece 100 has a central hole 110 and multiple through holes 120 surrounding the central hole 110. When the fixture 200 holds the workpiece 100, it transmits pressure to the wall of the central hole 110, causing a certain degree of elastic deformation. Due to the blocking effect of the through holes 120, the pressure generated by the fixture 200 is difficult to transmit to the wall of the central hole 110 corresponding to the through holes 120, resulting in uneven elastic deformation of the wall of the central hole 110. After the internal teeth are machined into the wall of the central hole 110 and the fixture 200 is removed, the wall of the central hole 110 will spring back to a certain extent, leading to an increase in radial runout and pitch error of the internal teeth.

[0055] To improve the machining accuracy of workpiece 100, refer to Figure 1 and Figure 10As shown, in another embodiment of the present invention, the workpiece 100 can be a pin gear housing 330 used in an RV reducer 300, or a rigid wheel 400 used in a harmonic reducer. In an embodiment of the present invention, the workpiece 100 is configured to be clamped by an annular tensioning part 210 of a clamp 200, which is not shown in the schematic diagram. The workpiece 100 has a central hole 110 and a plurality of through holes 120 spaced around the central hole 110. Along the circumference of the central hole 110, the region where the maximum central angle of the through hole 120 corresponds to the center of the central hole 110 is located is a fifth region 420. The outer wall surface of the workpiece 100 is provided with a protrusion 111 in the fifth region 420, and a recess 112 is formed between two adjacent protrusions 111. When the fixture 200 clamps the workpiece 100, the tensioning part 210 is sleeved on the outer wall surface of the workpiece 100, and the inner wall of the tensioning part 210 abuts against the protrusion 111, while the inner wall of the tensioning part 210 and the recess 112 are spaced apart. It should be noted that the inner wall of the annular tensioning part 210 can expand to clamp the outer wall surface of the workpiece 100, thereby facilitating the machining of the hole wall of the center hole 110 of the workpiece 100.

[0056] Understandably, by adopting the above solution, since the protrusion 111 is located in the fifth region 420 of the central hole 110, under the obstruction of the through hole 120, it is difficult for the tensioning part 210 and the protrusion 111 to transmit the pressure generated by the fixture 200 to the outer wall surface of the workpiece 100 when they abut against each other; and when the tensioning part 210 and the recess 112 are spaced apart, the pressure generated by the fixture 200 can be prevented from being transmitted to the workpiece 100 through the recess 112, thereby ensuring the uniformity of the inner wall surface undulation when the workpiece 100 is clamped, reducing the machining error of the workpiece 100, improving the machining accuracy of the workpiece 100, and thus extending the durability of the workpiece 100.

[0057] Reference Figure 10As shown in the embodiment of the present invention, the workpiece 100 is a rigid wheel 400, and the through hole 120 is a second mounting hole 410. The second mounting hole 410 is used for fasteners such as screws and bolts to pass through, thereby mounting the rigid wheel 400 on a robot or other equipment; or the second mounting hole 410 is used for positioning with a structure such as a pin, thereby positioning the rigid wheel 400. The rigid wheel 400 belongs to a harmonic reducer, which also includes a flexible wheel and a wave generator. The wave generator is embedded in the flexible wheel, and the outer teeth of the flexible wheel mesh with the inner teeth of the rigid wheel 400. The rotation of the wave generator drives the flexible wheel and the rigid wheel 400 to move relative to each other. Therefore, the rigid wheel 400 needs to be machined with inner teeth. During machining, the outer wall surface of the rigid wheel 400 needs to be clamped by a fixture 200 for machining. Since the rigid wheel 400 has multiple second mounting holes 410, when the fixture 200 clamps the rigid wheel 400, uneven elastic deformation may occur at the center hole 110 of the rigid wheel 400. Therefore, by providing a protrusion 111 at the corresponding position of the first mounting hole 313 and a recess 112 between adjacent protrusions 111, the uniformity of the inner wall surface undulation when the workpiece 100 is clamped can be improved, the machining accuracy of the rigid wheel 400 can be improved, and the smoothness of the harmonic reducer operation can be enhanced. It should be noted that when the outer wall of the rigid wheel 400 needs to mate with other parts, the outer wall of the rigid wheel 400 can be machined to remove the protrusion 111, so that the outer wall surface of the rigid wheel 400 is constructed as a complete arc surface. When the protrusion 111 and the recess 112 do not affect the mating effect of the rigid wheel 400 with other parts, the protrusion 111 and the recess 112 can also be retained.

[0058] Continue to refer to Figure 10 As shown, in the embodiment of the present invention, a plurality of second mounting holes 410 are evenly spaced along the circumference of the rigid wheel 400. Therefore, the protrusions 111 are also evenly spaced on the outer wall of the rigid wheel 400, which can improve the uniformity of the force on the rigid wheel 400 when the clamp 200 clamps the rigid wheel 400, so as to avoid the rigid wheel 400 as a whole from deforming and causing an increase in processing error.

[0059] In embodiments of the present invention, the workpiece 100 may also be a needle-tooth shell 330, and the through hole 120 is a third mounting hole, with multiple third mounting holes evenly spaced along the circumference of the needle-tooth shell 330. The effect is similar to that when the workpiece 100 is a rigid wheel 400, and will not be described in detail here.

[0060] A speed reducer according to one embodiment of the present invention includes the workpiece 100 of the above embodiments. Depending on the type of part being processed, the speed reducer can be an RV speed reducer 300, a harmonic speed reducer, or a cycloidal speed reducer. The speed reducer of this embodiment uses the workpiece 100 of the above embodiments. By providing a protrusion 111 and a recess 112 on the wall of the central hole 110 of the workpiece 100 at a corresponding position, when the clamp 200 clamps the workpiece 100, a tensioning part 210 passes through the central hole 110, and the side wall of the tensioning part 210 abuts against the protrusion 111, thereby restricting the position of the workpiece 100. Since the protrusion 111 is located in the first region 130 of the central hole 110, the tensioning part 210 and the protrusion 111 are separated by the through hole 120, making it difficult to transmit the pressure generated by the clamp 200 to the outer wall surface of the workpiece 100 when they abut. Furthermore, when the tensioning part 210 and the recess 112 are spaced apart, the pressure generated by the clamp 200 can also be prevented from being transmitted to the workpiece 100 through the recess 112, thereby ensuring the uniformity of the undulation of the outer wall surface when the cycloidal wheel 310 is clamped, so as to improve the machining accuracy of the workpiece 100.

[0061] Since the reducer adopts all the technical solutions of the workpiece 100 in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments, which will not be repeated here.

[0062] 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 workpiece, characterized in that, The outer peripheral wall of the workpiece is a bearing part. The workpiece has a central hole and a plurality of through holes spaced apart around the central hole. Along the circumference of the central hole, the area where the maximum central angle of each through hole corresponds to the center of the central hole is located is a first region. The hole wall of the central hole is provided with a protrusion in the first region, and a concave part is formed between two adjacent protrusions.

2. The workpiece according to claim 1, characterized in that: Along the radial direction of the central hole, the maximum depth of the recess is H, which satisfies H≥0.01mm.

3. The workpiece according to claim 1, characterized in that: The workpiece is a cycloidal wheel, the through hole is an irregularly shaped hole through which the support column of the planetary carrier passes, and the bearing part is configured as an annular external toothed part.

4. The workpiece according to claim 3, characterized in that: The cycloidal wheel is also provided with a plurality of crankshaft holes for the crankshaft to pass through. The crankshaft holes are located between at least some of the adjacent irregular holes. Along the circumference of the central hole, the area where the maximum central angle of each crankshaft hole corresponds to the center of the central hole is located is a second area. A recess is passed through the second area along the circumference of the central hole, and both ends of the recess are located outside the second area.

5. The workpiece according to claim 4, characterized in that: Along the radial direction of the central hole, the minimum distance between the irregular hole and the central hole is less than the minimum distance between the crankshaft hole and the central hole; and / or, On the projection plane perpendicular to the axis of the central hole, the opening area of ​​the crankshaft hole is smaller than the opening area of ​​the irregular hole.

6. The workpiece according to claim 1, characterized in that: The workpiece is a cycloidal wheel, the bearing part is configured as an annular external toothed part, the through hole is a crankshaft hole for the crankshaft to pass through, and an irregular hole is provided between adjacent crankshaft holes. Along the circumference of the central hole, the area where the maximum central angle of the center of the central hole is located between each two adjacent crankshaft holes is a third region, and at least a part of the structure of one of the recesses is located in a corresponding third region.

7. The workpiece according to claim 6, characterized in that: Along the radial direction of the central hole, the minimum distance between the crankshaft hole and the central hole is less than the minimum distance between the irregular hole and the central hole; and / or, On the projection plane perpendicular to the axis of the central hole, the opening area of ​​the irregular hole is smaller than the opening area of ​​the crankshaft hole.

8. The workpiece according to claim 1, characterized in that: The workpiece is a cycloidal wheel, the bearing part is configured as an annular external toothed part, the through hole is a first mounting hole for the support column of the planetary carrier to pass through, three first mounting holes arranged sequentially along the circumference of the central hole constitute a hole group, the hole group is provided with two groups spaced apart, a crankshaft hole is provided between adjacent hole groups, along the circumference of the central hole, the area where the maximum central angle of the center of the central hole is located between adjacent hole groups is a fourth region, and at least a part of the structure of one of the recesses is located in a corresponding fourth region.

9. The workpiece according to claim 8, characterized in that: Along the radial direction of the central hole, the minimum distance between the first mounting hole and the central hole is less than the minimum distance between the crankshaft hole and the central hole; and / or, On the projection plane perpendicular to the axis of the central hole, the opening area of ​​the crankshaft hole is smaller than the opening area of ​​the first mounting hole.

10. The workpiece according to claim 1, characterized in that: The workpiece is a flange, the bearing portion is configured as an annular first outer raceway, the through hole is a first mating hole, and a plurality of first mating holes are evenly spaced along the circumference of the central hole; or... The workpiece is a planetary carrier, the bearing portion is configured as an annular second outer raceway, the through hole is a second mating hole for the crankshaft to pass through, and a plurality of second mating holes are evenly spaced along the circumference of the central hole.

11. The workpiece according to any one of claims 1 to 10, characterized in that: On a projection plane perpendicular to the axis of the central hole, the central hole has a symmetrical structure.

12. A workpiece, characterized in that, The workpiece has a central hole and a plurality of through holes spaced apart around the central hole. The wall of the central hole is a bearing portion. Along the circumference of the central hole, the region where the largest central angle of the through holes corresponds to the center of the central hole is located is a fifth region. The outer wall surface of the workpiece is provided with a protrusion in the fifth region, and a concave portion is formed between two adjacent protrusions.

13. The workpiece according to claim 12, characterized in that: The workpiece is a rigid wheel, the bearing portion is configured as an annular internal tooth portion, and the through hole is a second mounting hole for fasteners to pass through.

14. A speed reducer, characterized in that: Includes the workpiece as described in any one of claims 1 to 13.

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