A compact heavy-duty precision rotary mechanism

Abstract

The utility model discloses a compact heavy load precision rotary mechanism, including four section arm, clamp rotary cylinder, clamp rotary drive, speed reducer seat and half flat axle, the speed reducer seat is located in the clamp rotary cylinder, and the speed reducer seat is opened the waist -shaped hole of vertical intersection in the clamp rotary cylinder axis, and half flat axle includes rotating axle section and is equipped with two parallel locating surface flat axle section, and the clamp rotary cylinder is opened the axle hole of vertical intersection in the clamp rotary cylinder axis, and rotating axle section inserts the axle hole, and flat axle section inserts the waist -shaped hole, and locating surface and waist -shaped hole side wall abut, and flat axle section and waist -shaped hole have the gap along the axial direction of clamp rotary cylinder, and the speed reducer seat and clamp rotary cylinder have the gap along the axial direction of half flat axle, and clamp rotary drive drives the rotation of speed reducer seat to drive the rotation of clamp rotary cylinder relative to four section arm. The utility model releases two translation directions and two rotation directions freedom, and limits the translation and rotation freedom related with the rotation precision, avoids the phenomenon of holding back the strength, ensures the precision transmission and compact structure.

Description

Technical Field

[0001] This utility model relates to the field of mechanical equipment technology, and in particular to a compact heavy-duty precision rotary mechanism. Background Technology

[0002] Existing robotic arm active rotary joints typically have two structures: the first uses a servo motor for direct drive with a rigid connection, and the second uses an external servo motor and reducer driven by gears or synchronous belts. The first structure has a relatively low rotary drive torque, and the servo motor's output shaft is prone to radial loads, resulting in stiffness. The second structure, to achieve the same transmission accuracy and load capacity, requires extremely high machining precision for its components, and the servo motor and reducer occupy external dimensions, making it unsuitable for applications where multiple motion mechanisms are densely arranged in confined spaces. Therefore, a rotary mechanism that enables precise transmission, prevents stiffness, and has a compact structure is needed. Utility Model Content

[0003] This invention provides a compact, heavy-duty, precision rotary mechanism to solve the aforementioned technical problems.

[0004] To achieve the above objectives, the technical solution of this utility model is as follows: A compact heavy-duty precision rotary mechanism includes: a four-section arm, a clamp rotating cylinder, a clamp rotating drive, a reducer base, and a semi-flat shaft; The clamp rotating cylinder is rotatably connected to the four-section arm; The reducer base is located inside the clamp rotating cylinder, and the reducer base has an oblong hole whose axis is perpendicular to the axis of the clamp rotating cylinder; The semi-flat shaft includes a rotating shaft section and a flat shaft section. The flat shaft section has two parallel positioning surfaces. The jig rotating cylinder has a shaft hole with its axis perpendicular to the axis of the jig rotating cylinder. The rotating shaft section is inserted into the shaft hole, and the flat shaft section is inserted into the oblong hole. The two positioning surfaces abut against the two side walls of the oblong hole. There is a gap between the flat shaft section and the oblong hole along the axial direction of the jig rotating cylinder. There is also a gap between the reducer base and the jig rotating cylinder along the axial direction of the semi-flat shaft. The clamp rotary driver drives the reducer base to rotate, which in turn drives the clamp rotary cylinder to rotate relative to the four-section arm via the semi-flat shaft.

[0005] Preferably, the reducer base includes: a housing, a reducer base flange, and a waist-shaped sleeve; the reducer base flange is fixed to the housing and is used to connect the clamp rotary drive; the waist-shaped sleeve is fixed to the housing and has a vertically arranged waist-shaped hole to cooperate with the flat shaft section, and a gap is left between the end face of the waist-shaped sleeve and the clamp rotary cylinder.

[0006] Preferably, two waist-shaped sleeves are symmetrically arranged on the shell, and both waist-shaped sleeves are provided with waist-shaped holes and the two waist-shaped holes are coaxial.

[0007] Preferably, the clamp rotary drive includes a motor and a reducer. The output end of the reducer is fixedly connected to the four-section arm. The housing is fixedly connected to the reducer base through the reducer base flange. The input end of the reducer is connected to the motor. The housing is annular, and the motor and reducer pass through the housing.

[0008] Preferably, the clamp rotating cylinder and the four-section arm are rotatably connected via a slewing bearing.

[0009] Preferably, the clamp rotating cylinder includes a cylinder body and a mounting ear, the mounting ear is inserted into the cylinder wall and fixed on the cylinder body, and a shaft hole is formed on the mounting ear.

[0010] Preferably, the clamp rotating cylinder further includes a clamp rotating cylinder flange, which is fixed on the cylinder body and connected to the slewing bearing.

[0011] Preferably, the four-section boom is provided with a front outer flange and a front inner flange. The front inner flange is located inside the front outer flange. The front inner flange is fixedly connected to the output end of the reducer, and the front outer flange is connected to the slewing bearing.

[0012] Beneficial effects: This application discloses a compact heavy-duty precision rotary mechanism that, by setting a reducer base and a semi-flat shaft, utilizes the fit between the flat shaft section and the oblong hole, as well as the reserved gap between the reducer base and the clamping rotating cylinder, to release the two translational degrees of freedom and the corresponding two rotational degrees of freedom, while limiting the translational and rotational degrees of freedom that are directly related to the rotational accuracy, thereby effectively avoiding the phenomenon of stiffness, ensuring precision transmission, and having a compact overall structure. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 2 This is a cross-sectional view of a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 3 This is a schematic diagram of the degrees of freedom of a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 4 This is a schematic diagram of the four-section arm of a compact heavy-duty precision rotary mechanism disclosed in this utility model. Figure 1 ; Figure 5 This is a schematic diagram of the four-section arm of a compact heavy-duty precision rotary mechanism disclosed in this utility model. Figure 2 ; Figure 6 This is a schematic diagram of the structure of the clamping rotating cylinder of a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 7 This is a schematic diagram of the structure of a reducer base for a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 8 This is a schematic diagram of the structure of a semi-flat shaft of a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 9 for Figure 2 A cross-sectional view of KK.

[0015] In the diagram: 4. Four-section arm; 41. Reducer base; 411. Waist-shaped hole; 412. Housing; 413. Reducer base flange; 414. Waist-shaped hole sleeve; 42. Semi-flat shaft; 421. Rotating shaft section; 422. Flat shaft section; 423. Positioning surface; 431. Front outer flange; 432. Front inner flange; 51. Fixture rotating cylinder; 511. Shaft hole; 512. Cylinder body; 513. Mounting ear; 514. Fixture rotating cylinder flange; 521. Motor; 522. Reducer; 53. Slewing bearing. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] A compact, heavy-duty precision rotary mechanism, combined with Figures 1-9 As shown, it includes: a four-section arm 4, a clamp rotating cylinder 51, a clamp rotating drive, a reducer base 41, and a semi-flat shaft 42; The clamp rotating cylinder 51 is rotatably connected to the four-section arm 4; The reducer base 41 is located inside the clamp rotating cylinder 51, and the reducer base 41 has an oblong hole 411 whose axis is perpendicular to the axis of the clamp rotating cylinder 51. The semi-flat shaft 42 includes a rotating shaft section 421 and a flat shaft section 422. The flat shaft section 422 is provided with two parallel positioning surfaces 423. The clamping rotating cylinder 51 is provided with a shaft hole 511 whose axis is perpendicular to the axis of the clamping rotating cylinder 51. The rotating shaft section 421 is inserted into the shaft hole 511, and the flat shaft section 422 is inserted into the oblong hole 411. The two positioning surfaces 423 abut against the two side walls of the oblong hole 411. The flat shaft section 422 and the oblong hole 411 are separated by a gap along the axial direction of the clamping rotating cylinder 51. The reducer base 41 and the clamping rotating cylinder 51 are separated by a gap along the axial direction of the semi-flat shaft 42. The clamp rotary driver drives the reducer base 41 to rotate, thereby driving the clamp rotary cylinder 51 to rotate relative to the four-section arm 4 via the semi-flat shaft 42.

[0018] This application achieves the release of two translational degrees of freedom and corresponding two rotational degrees of freedom by setting up a reducer base 41 and a semi-flat shaft 42, utilizing the cooperation between the flat shaft section 422 and the oblong hole 411, and the reserved gap between the reducer base 41 and the clamp rotating cylinder 51. At the same time, it limits the translational and rotational degrees of freedom that are directly related to the rotational accuracy, thereby effectively avoiding the phenomenon of stiffness, ensuring precision transmission, and the overall structure is compact.

[0019] Specifically, such as Figure 1 , Figure 2 and Figure 5 As shown, a coordinate system is established to explain in detail the degree of freedom control of the rotary mechanism. The radial direction of the clamp rotary actuator, i.e., the axial direction of the shaft hole 511, is taken as the X-axis; the axial direction of the clamp rotary actuator is taken as the Z-axis; the Y-axis is the radial direction of the clamp rotary actuator and is perpendicular to both the X-axis and Z-axis; the rotation around the X-axis is Mx, the rotation around the Y-axis is My, and the rotation around the Z-axis is Mz.

[0020] The reducer base 41 and the clamp rotating cylinder 51 have clearances △1 and △2 along the axial direction of the semi-flat shaft 42, and the flat shaft section 422 and the oblong hole 411 have clearances △3 and △4 along the axial direction of the clamp rotating cylinder 51. If one of the four-section arm 4 or the clamp rotating cylinder 51 is fixed, without active drive from the clamp rotating drive, the unfixed component is allowed to translate along the X-axis due to the clearances △1 and △2; the unfixed component is allowed to translate along the Z-axis and rotate around the Y-axis (My) due to the clearances △3 and △4; and the unfixed component is allowed to rotate around the X-axis (Mx) due to the fit between the rotating shaft section 421 and the shaft hole 511. Since the four degrees of freedom X, Z, Mx, and My are not constrained, the dimensional accuracy requirements in these directions are low, and no stiffness is caused. The remaining two degrees of freedom, Y and Mz, can be used: the Y-axis direction can be set for a smaller load, while Mz is for rotary joint movements requiring precise transmission.

[0021] In summary, this application, through the connection between the reducer base 41 and the semi-flat shaft 42, selectively releases degrees of freedom. It loosens constraints in the main overturning moment directions (Mx and My), the normal direction (X) of the slewing bearing 53's rotation axis, and the direction (Z) of the slewing bearing 53's rotation axis, while precisely constraining only the rotation direction (Mz) and the normal direction (Y) of the slewing bearing 53's rotation axis. This ensures transmission accuracy, avoids damage to the jig rotary drive, and reduces the difficulty of machining and assembling parts.

[0022] Preferably, the reducer base 41 includes: a housing 412, a reducer base flange 413, and a waist-shaped sleeve 414; the reducer base flange 413 is fixed to the housing 412 and is used to connect the jig rotary drive, so that the reducer base 41 and the jig rotary drive rotate coaxially; the waist-shaped sleeve 414 is fixed to the housing 412 and has a vertically arranged waist-shaped hole 411 to cooperate with the flat shaft section 422. The size of the waist-shaped hole 411 along the Z-axis is larger than the size of the flat shaft section 422, so that gaps △3 and △4 can be left on the upper and lower sides of the flat shaft section 422; a gap is left between the end face of the waist-shaped sleeve 414 and the jig rotary cylinder 51. The two positioning surfaces 423 of the flat shaft section 422 respectively abut against the flat wall surfaces on both sides of the waist-shaped hole 411, thereby precisely limiting the degree of freedom Y. The arrangement of the waist-shaped sleeve 414, the waist-shaped hole 411, and the flat shaft section 422 is conducive to precise machining, thereby ensuring precise constraints.

[0023] Specifically, the main body of the semi-flat shaft 42 is a cylinder, with two parallel positioning surfaces 423 milled at one end to form a flat shaft section 422 and a rotating shaft section 421. The housing 412, the reducer base flange 413, and the waist hole sleeve 414 are integral castings or welded parts. To obtain stable dimensional accuracy, the reducer base 41 can be integrally cast or welded and then subjected to stress-relief annealing.

[0024] Preferably, two oblong sleeves 414 are symmetrically arranged on the housing 412. Each oblong sleeve 414 has an oblong hole 411, and the two oblong holes 411 are coaxial, ensuring that they are perpendicular and orthogonal to the axis of the reducer base flange 413, thereby ensuring the positional accuracy after connection with the clamp rotary drive. At the same time, the two oblong sleeves 414, together with the two semi-flat shafts 42, can form symmetrical force-bearing points, which is beneficial for torque transmission and improving structural rigidity.

[0025] Preferably, the clamp rotary drive includes a motor 521 and a reducer 522. The output end of the reducer 522 is fixedly connected to the four-section arm 4. The housing is fixedly connected to the reducer base 41 through the reducer base flange 413. The input end of the reducer 522 is connected to the motor 521. The housing 412 is annular, and the motor 521 and the reducer 522 pass through the housing 412.

[0026] Specifically, the reducer 522 is a high-precision planetary reducer, and the motor 521 is a servo motor. The servo motor has a brake and a rotary encoder inside. The output end of the reducer 522 is positioned and connected to the four-section arm 4 by a flange and a stop. The housing of the reducer 522 is also positioned and connected to the reducer base 41 by a flange and a stop. The servo motor drives the high-precision planetary reducer, thereby causing the reducer base 41 to drive the clamp rotating cylinder 51 to rotate relative to the four-section arm 4.

[0027] Preferably, the clamping rotating cylinder 51 and the four-section arm 4 are rotatably connected via a slewing bearing 53 to form a rotating joint. The reducer 522 is coaxially mounted inside the gearless slewing bearing 53, making full use of the internal space of the clamping rotating cylinder 51 to arrange the reducer 522, reducer base 41, and motor 521. Furthermore, the reducer 522 passes through the inner ring of the reducer base 41, allowing it to be matched with a high-ratio, heavy-duty, high-precision planetary reducer, resulting in a more compact structure and smaller overall dimensions. Therefore, the rotating mechanism of this application achieves both high-precision transmission and weight reduction; it is suitable for equipment with multiple motion mechanisms densely arranged in confined spaces, especially multi-degree-of-freedom robotic arms.

[0028] Preferably, the clamp rotating cylinder 51 includes a cylinder body 512 and a mounting ear 513. The mounting ear 513 passes through the cylinder wall of the cylinder body 512 and is fixed on the cylinder body 512. A shaft hole 511 is formed on the mounting ear 513. This can reduce the volume of the clamp rotating cylinder 51 while ensuring the rigidity of the connection position with the semi-flat shaft 42.

[0029] Preferably, the clamp rotating cylinder 51 further includes a clamp rotating cylinder flange 514, which is fixed on the cylinder body 512 and is connected to the outer ring flange of the slewing bearing 53.

[0030] Preferably, the four-section arm 4 is provided with a front outer flange 431 and a front inner flange 432. The front inner flange 432 is located inside the front outer flange 431 and is fixedly connected to the output end of the reducer 522. The front outer flange 431 is connected to the inner ring flange of the slewing bearing 53, thereby realizing the rotational connection between the clamping rotating cylinder 51 and the four-section arm 4. In this embodiment, the front outer flange 431 and the front inner flange 432 are integrally machined to ensure coaxiality.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A compact, heavy-duty, precision rotary mechanism, characterized in that, include: Four-section arm (4), clamp rotating cylinder (51), clamp rotating drive, reducer base (41) and half flat shaft (42). The clamp rotating cylinder (51) is rotatably connected to the four-section arm (4); The reducer base (41) is located inside the clamp rotating cylinder (51), and the reducer base (41) has an oblong hole (411) whose axis is perpendicular to the axis of the clamp rotating cylinder (51). The semi-flat shaft (42) includes a rotating shaft section (421) and a flat shaft section (422). The flat shaft section (422) has two parallel positioning surfaces (423). The clamping rotating cylinder (51) has a shaft hole (511) whose axis is perpendicular to the axis of the clamping rotating cylinder (51). The rotating shaft section (421) is inserted into the shaft hole (511), and the flat shaft section (422) is inserted into the waist-shaped hole (411). The two positioning surfaces (423) abut against the two side walls of the waist-shaped hole (411). The flat shaft section (422) and the waist-shaped hole (411) have a gap along the axial direction of the clamping rotating cylinder (51). The reducer base (41) and the clamping rotating cylinder (51) have a gap along the axial direction of the semi-flat shaft (42). The clamp rotary driver drives the reducer base (41) to rotate, thereby driving the clamp rotary cylinder (51) to rotate relative to the four-section arm (4) via the semi-flat shaft (42).

2. The compact heavy-duty precision rotary mechanism according to claim 1, characterized in that, The reducer base (41) includes: a housing (412), a reducer base flange (413), and a waist hole sleeve (414); the reducer base flange (413) is fixed on the housing (412) and is used to connect the clamp rotary drive; the waist hole sleeve (414) is fixed on the housing (412) and has a vertically arranged waist-shaped hole (411) to cooperate with the flat shaft section (422), and a gap is left between the end face of the waist hole sleeve (414) and the clamp rotating cylinder (51).

3. The compact heavy-duty precision rotary mechanism according to claim 2, characterized in that, Two waist-shaped sleeves (414) are symmetrically arranged on the housing (412). Both waist-shaped sleeves (414) have waist-shaped holes (411) and the two waist-shaped holes (411) are coaxial.

4. A compact, heavy-duty precision rotary mechanism according to claim 3, characterized in that, The clamp rotary drive includes a motor (521) and a reducer (522). The output end of the reducer (522) is fixedly connected to the four-section arm (4). The housing is fixedly connected to the reducer base (41) through the reducer base flange (413). The input end of the reducer (522) is connected to the motor (521). The housing (412) is annular, and the motor (521) and the reducer (522) pass through the housing (412).

5. A compact, heavy-duty precision rotary mechanism according to claim 4, characterized in that, The clamp rotating cylinder (51) and the four-section arm (4) are rotatably connected by a slewing bearing (53).

6. A compact heavy-duty precision rotary mechanism according to any one of claims 1-5, characterized in that, The clamp rotating cylinder (51) includes a cylinder body (512) and a mounting ear (513). The mounting ear (513) passes through the cylinder wall of the cylinder body (512) and is fixed on the cylinder body (512). A shaft hole (511) is opened on the mounting ear (513).

7. A compact heavy-duty precision rotary mechanism according to claim 6, characterized in that, The clamp rotating cylinder (51) also includes a clamp rotating cylinder flange (514), which is fixed on the cylinder body (512) and connected to the slewing bearing (53).

8. A compact, heavy-duty precision rotary mechanism according to claim 5, characterized in that, The four-section arm (4) is provided with a front outer flange (431) and a front inner flange (432). The front inner flange (432) is located inside the front outer flange (431). The front inner flange (432) is fixedly connected to the output end of the reducer (522). The front outer flange (431) is connected to the slewing bearing (53).

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