A compact heavy-duty precision rotary mechanism

Abstract

The utility model discloses a compact heavy load precision rotary mechanism, including three section arms, four section arms, rotary driver and rotary arm part, rotary arm part includes flat shaft, waist hole cover, joint bearing and rotary arm, flat shaft is established on four section arms and the rotary axis of parallel four section arms, is equipped with two parallel locating surfaces on flat shaft, waist hole cover is set up waist hole and is covered on flat shaft, two locating surfaces and the two side walls of waist hole abut, and flat shaft and waist hole have the clearance along the direction of the common perpendicular line of flat shaft axis and four section arms rotary axis, and waist hole cover and four section arms have the clearance, the arm output end of rotary arm is established outside waist hole cover through joint bearing, and arm input end is connected with rotary driver, and rotary driver drives arm input end to rotate, and four section arms are driven to rotate through flat shaft, the utility model releases two translation and two rotation direction degrees of freedom, limits the translation and rotation degree of freedom related with rotary precision, avoids the phenomenon of holding back strength, ensures 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 three-section arm, a four-section arm, a rotary drive, and a rotary arm assembly; The four-section boom is rotatably connected to the three-section boom; The slewing arm assembly includes: a flat shaft, a waist-shaped sleeve, a spherical bearing, and a slewing arm; the flat shaft is fixed on the four-section arm and its axis is parallel to the rotation axis of the four-section arm, and the flat shaft has two mutually parallel positioning surfaces; the waist-shaped sleeve has a waist-shaped hole, and the waist-shaped sleeve is fitted onto the flat shaft, with the two positioning surfaces abutting against the two side walls of the waist-shaped hole, and a gap is left between the flat shaft and the waist-shaped hole along the common perpendicular direction of the flat shaft axis and the rotation axis of the four-section arm, and a gap is left between the waist-shaped sleeve and the four-section arm; the arm output end of the slewing arm is located on the outside of the waist-shaped sleeve through a spherical bearing, and the arm input end is connected to the rotary drive; The rotary actuator drives the input end of the arm to rotate, thereby driving the four-section arm to rotate relative to the three-section arm via the flat shaft.

[0005] Preferably, the four-section arm has a mounting cavity, and the flat shaft and the rotary arm are located in the mounting cavity.

[0006] Preferably, the four-section arm has two coaxial mounting holes, a bushing is fixed in the mounting hole, a shaft hole is opened in the center of the bushing, and the planes at both ends of the flat shaft parallel to its axis respectively abut against the plane of the shaft hole; the ends of the flat shaft are connected to a shaft cover by screws, and the shaft cover is pressed on the bushing.

[0007] Preferably, the outer periphery of the waist hole sleeve is provided with an outer boss and an outer retaining spring groove, the inner ring of the spherical bearing is sleeved on the waist hole sleeve and abuts against the outer boss, and the spherical retaining spring is inserted into the outer retaining spring groove to restrict the axial movement of the inner ring of the spherical bearing; The arm output end has a joint mounting hole, which contains an inner boss and an inner retaining spring groove. The outer ring of the joint bearing is located in the joint mounting hole and abuts against the inner boss. The hole is secured with a retaining spring into the inner retaining spring groove to restrict the axial movement of the outer ring of the joint bearing.

[0008] Preferably, the four-section boom and the three-section boom are rotatably connected by a slewing bearing.

[0009] Preferably, the four-section boom is provided with a four-section boom flange, and the three-section boom is provided with a three-section boom flange. The four-section boom flange and the three-section boom flange are respectively connected to the inner and outer rings of the slewing bearing.

[0010] Preferably, the three-section arm flange is also fixedly connected to a reducer base, which includes: a housing, an upper flange and a lower flange. The housing is annular and its lower end extends through the four-section arm flange into the four-section arm mounting cavity. The upper end of the housing is coaxially fixed to the three-section arm flange through the upper flange, and the lower end is connected to the rotary drive through the lower flange. The rotary drive passes through the housing.

[0011] Preferably, the rotary drive includes a motor and a reducer. The reducer housing is provided with a reducer flange, which is fixedly connected to the lower flange. The output end of the reducer is fixedly connected to the input end of the arm, and the input end of the reducer is connected to the motor.

[0012] Preferably, the reducer flange is located above the lower flange, and a screw hole annular plate is provided above the reducer flange. The screw hole annular plate has threaded holes, and the screw passes through the lower flange and the reducer flange and is screwed into the threaded holes on the screw hole annular plate. A lower operating port is provided on the four-section arm, which is located below the four-section arm flange and exposes the lower flange.

[0013] Preferably, the slewing arm includes: an arm output end, an arm input end, and an arm inclined connecting section. The arm output end is parallel to the arm input end and is higher than the arm input end. The arm inclined connecting section connects the arm input end and the arm output end at an inclination. The arm input end is provided with an input arm flange, which is fixedly connected to the output end of the reducer.

[0014] Beneficial effects: The compact heavy-duty precision rotary mechanism disclosed in this application achieves the release of two translational degrees of freedom and corresponding two rotational degrees of freedom by setting up a rotary arm component, utilizing the cooperation between the flat shaft and the oblong hole, the cooperation between the spherical bearing and the oblong hole sleeve, and the gap between the oblong hole sleeve and the four-section arm. At the same time, it limits the translational and rotational degrees of freedom that are directly related to the rotational accuracy of the rotary arm, thereby effectively avoiding the phenomenon of stiffness, ensuring precision transmission, and the overall structure is compact. Attached Figure Description

[0015] 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.

[0016] 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 for Figure 2 A magnified view of part I; Figure 4 for Figure 2 Enlarged view of a section of section II; Figure 5 for Figure 2 Enlarged view of a section of section III; Figure 6 for Figure 3 Sectional view of KK; Figure 7 This is a schematic diagram of the degrees of freedom of a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 8 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 9 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 10 This is a schematic diagram of the four-section arm of a compact heavy-duty precision rotary mechanism disclosed in this utility model. Figure 3 ; Figure 11 This is a cross-sectional view of the four-section arm of a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 12 This is a structural schematic diagram of the rotary arm component of a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 13 This is a schematic diagram of the structure of the rotary arm of a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 14 This is a schematic diagram of the waist hole sleeve of a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 15This is a schematic diagram of the structure of a flat shaft for a compact heavy-duty precision rotary mechanism disclosed in this utility model; Figure 16 This is a schematic diagram of the three-section arm of a compact heavy-duty precision rotary mechanism disclosed in this utility model. Figure 1 ; Figure 17 This is a schematic diagram of the three-section arm of a compact heavy-duty precision rotary mechanism disclosed in this utility model. Figure 2 ; Figure 18 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 19 This is a structural schematic diagram of a compact heavy-duty precision rotary mechanism comprising a three-section arm, a rotary driver, and a reducer base assembly, as disclosed in this utility model. Figure 20 This is a front view of the three-section arm, rotary driver, and reducer base assembly of a compact heavy-duty precision rotary mechanism disclosed in this utility model. Figure 21 This is a cross-sectional view of a compact heavy-duty precision rotary mechanism comprising a three-section arm, a rotary driver, and a reducer base assembly, as disclosed in this utility model.

[0017] In the diagram: 3. Three-section arm; 4. Four-section arm; 441. Flat shaft; 4411. Positioning surface; 442. Waist hole sleeve; 4421. Waist-shaped hole; 4422. Outer boss; 4423. Outer circlip groove; 4424. Shaft circlip; 443. Spherical bearing; 444. Rotary arm; 4441. Arm output end; 4442. Arm input end; 4443. Arm inclined connecting section; 4444. Joint mounting hole; 4445. Inner boss; 4446. Inner circlip groove; 4447. Hole circlip; 44 48. Input arm flange; 445. Mounting hole; 446. Bushing; 447. Shaft cover; 448. Lower operating port; 45. Slewing bearing; 451. Four-section arm flange; 452. Three-section arm flange; 46. Gearbox base; 461. Housing; 462. Upper flange; 463. Lower flange; 471. Motor; 472. Gearbox; 4721. Gearbox flange; 473. Annular plate with bolt holes; 481. Front end of four-section arm; 482. Middle section of four-section arm; 483. Rear end of four-section arm. Detailed Implementation

[0018] 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.

[0019] A compact, heavy-duty precision rotary mechanism, combined with Figures 1-21 As shown, it includes: a three-section arm 3, a four-section arm 4, a rotary actuator, and a slewing arm assembly; The four-section arm 4 is rotatably connected to the three-section arm 3; The rotary arm assembly includes: a flat shaft 441, a waist-shaped sleeve 442, a joint bearing 443, and a rotary arm 444; the flat shaft 441 is fixed on the four-section arm 4 and its axis is parallel to the rotation axis of the four-section arm 4. The flat shaft 441 has two mutually parallel positioning surfaces 4411; the waist-shaped sleeve 442 has a waist-shaped hole 4421 and is fitted onto the flat shaft 441. The two positioning surfaces 4411 abut against the two side walls of the waist-shaped hole 4421. There is a gap between the flat shaft 441 and the waist-shaped hole 4421 along the common perpendicular direction of the axis of the flat shaft 441 and the rotation axis of the four-section arm 4. There is also a gap between the waist-shaped sleeve 442 and the four-section arm 4; the arm output end 4441 of the rotary arm 444 is located outside the waist-shaped sleeve 442 through the joint bearing 443, and the arm input end 4442 is connected to the rotary driver; The rotary driver drives the input end 4442 of the drive arm to rotate, thereby driving the four-section arm 4 to rotate relative to the three-section arm 3 through the flat shaft 441.

[0020] This application, by setting up a rotary arm component, utilizes the cooperation between the flat shaft 441 and the oblong hole 4421, the cooperation between the spherical bearing 443 and the oblong hole sleeve 442, and the gap between the oblong hole sleeve 442 and the four-section arm 4, to achieve the release of 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 of the rotary arm 444, thereby effectively avoiding the phenomenon of stiffness, ensuring precision transmission, and having a compact overall structure.

[0021] Specifically, such as Figure 2 , Figure 3 , Figure 6 and Figure 7As shown, a coordinate system is established to explain in detail the degree of freedom control of the rotary mechanism. The X-axis is defined as the radial direction of the rotary actuator, i.e., the direction perpendicular to the common perpendicular of the axis of the flat shaft 441 and the axis of rotation of the four-section arm 4; the Z-axis is defined as the axial direction of the rotary actuator, i.e., the axis of rotation of the four-section arm 4; the Y-axis is the radial direction of the 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.

[0022] The flat shaft 441 and the waist-shaped hole 4421 of the waist-shaped sleeve 442 have gaps △1 and △2 along the X-axis, and the waist-shaped sleeve 442 and the four-section arm 4 have gaps △3 and △4 along the Z-axis. If one of the four-section arm 4 or the three-section arm 3 is fixed, without active drive from the rotary actuator, the unfixed component is allowed to translate along the X-axis due to the gaps △1 and △2; the unfixed component is allowed to translate along the Z-axis due to the gaps △3 and △4; the unfixed component is allowed to rotate around the Y-axis (My) due to the gaps △1 and △2 and the action of the spherical bearing 443; and the unfixed component is allowed to rotate around the X-axis (Mx) due to the action of the spherical bearing 443. 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 as the direction with a smaller load, while Mz is for rotary joint movements requiring precise transmission.

[0023] In summary, this application, through the structure of the slewing arm component, selectively releases degrees of freedom, loosening constraints in the main overturning moment directions (Mx and My), the normal direction (X) of the slewing bearing 45 rotation axis, and the direction (Z) of the slewing bearing 45 rotation axis, while precisely constraining only the rotation direction (Mz) and the normal direction (Y) of the slewing bearing 45 rotation axis. This ensures transmission accuracy, avoids damage to the rotary drive due to stiffness, and reduces the difficulty of machining and assembling parts.

[0024] Specifically, such as Figure 6 and 15As shown, the main body of the flat shaft 441 is a cylinder, with two parallel positioning surfaces 4411 milled onto it. The inner hole of the waist-shaped sleeve 442 is machined into a waist-shaped hole 4421 along the X-axis to mate with the flat shaft 441. The length of the waist-shaped hole 4421 is H, and the width is B. The length H of the waist-shaped hole 4421 is greater than the diameter of the flat shaft 441, and the width B of the waist-shaped hole 4421 is equal to the distance between the two positioning surfaces 4411, thus leaving gaps △1 and △2 on both sides of the flat shaft 441. Gaps △3 and △4 are left between the upper and lower end faces of the waist-shaped sleeve 442 and the four-section arm 4. The two positioning surfaces 4411 respectively abut against the flat wall surfaces on both sides of the waist-shaped hole 4421, thereby precisely limiting the degree of freedom Y. The arrangement of the waist-shaped sleeve 442, the waist-shaped hole 4421, and the flat shaft 441 facilitates precise machining, thereby ensuring precise constraints.

[0025] Preferably, the four-section arm 4 has a mounting cavity, in which the flat shaft 441 and the rotating arm 444 are located, making full use of the internal space of the four-section arm 4, resulting in a more compact structure and smaller overall dimensions.

[0026] Specifically, the four-section boom 4 includes: a front end 481, a middle section 482, and a rear end 483. The middle section 482 connects the front end 481 and the rear end 483. The entire four-section boom 4 adopts a hollow, weight-reducing structure formed by welding plates and stiffeners. A flat shaft 441 is installed at the front of the middle section 482, and a slewing arm 444 connects to the flat shaft 441, which passes through the rear end 483 and connects to the rotary actuator. Compared to directly driving the four-section boom 4 to rotate via the rotary actuator, this application not only balances overturning moment and rotational accuracy through the slewing arm component, but also increases the lever arm to increase torque through the slewing arm 444, which is beneficial for reducing the size of the rotary actuator and improving the load capacity of the four-section boom 4.

[0027] Preferably, the four-section arm 4 has two coaxial mounting holes 445, which are located on the upper and lower plates of the middle section 482 of the four-section arm, respectively. A bushing 446 is welded into each mounting hole 445, and the bushing 446 has a central shaft hole. The planes at both ends of the flat shaft 441, parallel to its axis, abut against the planes of the shaft hole. A shaft cap 447 is screwed to the end of the flat shaft 441, and the shaft cap 447 is pressed against the bushing 446. Since the fit length between the hole on the plate of the middle section 482 of the four-section arm and the flat shaft 441 is small, the bushing 446 is added to install the flat shaft 441. The planes at both ends of the flat shaft 441, parallel to its axis, abut against the shaft hole planes of the upper and lower bushings 446, thus limiting the rotation of the flat shaft 441. The shaft cap 447, pressed against the bushing 446, further limits the axial position of the flat shaft 441.

[0028] Specifically, reinforcing ribs are welded to the outer periphery of bushing 446 and the plate of the middle section 482 of the four-section arm to strengthen local areas. Through the cooperation of flat shaft 441 and two bushings 446, the upper and lower plates of the middle section 482 of the four-section arm are supported, thereby improving the rigidity of the four-section arm 4. The outer end of flat shaft 441 has a round hole that forms a stepped surface with the shaft hole. The end of flat shaft 441 has a threaded hole. The shaft cover 447 has a through hole corresponding to the threaded hole. Screws pass through the shaft cover 447 and are tightened at the end of flat shaft 441. The shaft cover 447 abuts against the stepped surface and the end face of flat shaft 441. The shaft cover 447 is recessed into flat shaft 441. The upper and lower shaft covers 447 limit the vertical position of flat shaft 441.

[0029] Preferably, the outer periphery of the waist hole sleeve 442 is provided with an outer boss 4422 and an outer retaining spring groove 4423, the inner ring of the spherical bearing 443 is sleeved on the waist hole sleeve 442 and abuts against the outer boss 4422, and the spherical retaining spring 4424 is inserted into the outer retaining spring groove 4423 to restrict the axial movement of the inner ring of the spherical bearing 443. The arm output end 4441 has a joint mounting hole 4444. The joint mounting hole 4444 has an inner boss 4445 and an inner retaining spring groove 4446. The outer ring of the joint bearing 443 is located in the joint mounting hole 4444 and abuts against the inner boss 4445. The retaining spring 4447 is inserted into the inner retaining spring groove 4446 to restrict the axial movement of the outer ring of the joint bearing 443.

[0030] Specifically, the outer boss 4422 is located above the inner boss 4445. The upper end of the inner ring of the spherical plain bearing 443 abuts against the outer boss 4422, and the shaft retainer 4424 abuts against the lower end of the inner ring of the spherical plain bearing 443. The lower end of the outer ring of the spherical plain bearing 443 abuts against the inner boss 4445, and the hole retainer 4447 abuts against the upper end of the outer ring of the spherical plain bearing 443. The vertical position of the inner ring of the spherical plain bearing 443 is defined by the outer boss 4422, the outer retainer groove 4423, and the shaft retainer 4424, and the vertical position of the outer ring of the spherical plain bearing 443 is defined by the inner boss 4445, the inner retainer groove 4446, and the hole retainer 4447, thereby achieving precise installation of the spherical plain bearing 443.

[0031] Preferably, the four-section arm 4 and the three-section arm 3 are rotatably connected by a slewing bearing 45 to form a rotating joint.

[0032] Preferably, the four-section arm 4 has a four-section arm flange 451 on its rear end 483, and the three-section arm 3 has a three-section arm flange 452. The four-section arm flange 451 and the three-section arm flange 452 are respectively connected to the inner and outer rings of the slewing bearing 45. This achieves a rotatable connection between the four-section arm 4 and the three-section arm 3, ensuring smooth rotation and slewing accuracy of the four-section arm 4 relative to the three-section arm 3.

[0033] Preferably, the three-section boom flange 452 is also fixedly connected to a reducer base 46. The reducer base 46 includes a housing 461, an upper flange 462, and a lower flange 463. The housing 461 is annular, and its lower end extends through the four-section boom flange 451 into the mounting cavity of the four-section boom 4. The upper end of the housing 461 is coaxially fixed to the three-section boom flange 452 via the upper flange 462, and the lower end is connected to the rotary drive via the lower flange 463. The rotary drive passes through the housing 461. By setting the reducer base 46 and utilizing the middle position of the housing 461, the rotary drive can be recessed into the four-section boom 4, making full use of the internal space of the four-section boom 4 and the three-section boom 3. This helps to reduce the height of the four-section boom 4 and the three-section boom 3, making it suitable for working spaces with limited height.

[0034] Specifically, the planes of the upper flange 462 and the lower flange 463 are parallel to each other, and their stops are coaxial. Both the upper flange 462 and the three-section boom flange 452 are connected to the inner ring of the slewing bearing 45. The upper flange 462 is located between the three-section boom flange 452 and the inner ring of the slewing bearing 45, and the housing 461 passes through the inner ring of the slewing bearing 45.

[0035] Specifically, the housing 461, upper flange 462, and lower flange 463 are integral castings or welded parts. To obtain stable dimensional accuracy, the reducer base 46 can be integrally cast or welded and then subjected to stress-relief annealing.

[0036] Preferably, the rotary drive includes a motor 471 and a reducer 472. The housing of the reducer 472 is provided with a reducer flange 4721. The reducer flange 4721 is fixedly connected to the lower flange 463. The output end of the reducer 472 is fixedly connected to the arm input end 4442. The input end of the reducer 472 is connected to the motor 471.

[0037] Specifically, the reducer 472 is a high-precision planetary reducer, and the motor 471 is a servo motor, which has an internal brake and rotary encoder. The servo motor drives the high-precision planetary reducer, thereby causing the reducer base 46 to rotate the rotary arm 444, which in turn drives the four-section arm 4 to rotate relative to the three-section arm 3. This application makes full use of the inner space of the slewing bearing 45 and the reducer base 46, which can match a high-ratio, heavy-duty, high-precision planetary reducer, making the rotary structure more compact and smaller in size. Therefore, the rotary mechanism of this application can achieve both high-precision transmission and weight reduction; it can be applied to equipment with multiple motion mechanisms densely arranged in a confined space, especially multi-degree-of-freedom robotic arms.

[0038] Specifically, the three-section arm 3 is also a hollow weight-reducing structure, and the input end of the reducer 472 adopts a right-angle form, so that the motor 471 can be horizontally installed inside the three-section arm 3.

[0039] Preferably, the reducer flange 4721 is located above the lower flange 463. A threaded annular plate 473 with threaded holes is provided above the reducer flange 4721. Screws pass through the lower flange 463 and the reducer flange 4721 and are screwed into the threaded holes on the annular plate 473. A lower operating port 448 is provided on the four-section arm 4, located below the four-section arm flange 451, exposing the lower flange 463. To fully utilize the internal space of the reducer base 46, the distance between the reducer base 46 and the reducer 472 is very small and the position is very deep, making it difficult to install the lower flange 463 and the reducer flange 4721. This application addresses this by inserting screws through the lower operating port 448, passing them through the lower flange 463 and the reducer flange 4721, and screwing them into the threaded holes on the annular plate 473. This allows the reducer 472 to be positioned and fixed by the clamping action of the annular plate 473 and the lower flange 463.

[0040] Preferably, the rotary arm 444 includes: an arm output end 4441, an arm input end 4442, and an arm inclined connecting section 4443. The arm output end 4441 is parallel to the arm input end 4442 and is higher than the arm input end 4442. The arm inclined connecting section 4443 obliquely connects the arm input end 4442 and the arm output end 4441. The arm input end 4442 is provided with an input arm flange 4448, which is fixedly connected to the output end of the reducer 472. The mechanism design of the rotary arm 444 in this application can ensure connection with the output end of the reducer 472 at a lower position and transmit the driving force to the middle position of the flat shaft 441, which is beneficial for arranging the joint bearing 443, the waist hole sleeve 442, and the bushing 446, thereby reducing the height of the four-section arm 4.

[0041] 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: Three-section boom (3), four-section boom (4), rotary drive and slewing arm assembly; The four-section arm (4) is rotatably connected to the three-section arm (3); The rotary arm component includes: a flat shaft (441), a waist-shaped sleeve (442), a joint bearing (443), and a rotary arm (444); the flat shaft (441) is fixed on the four-section arm (4) and its axis is parallel to the rotation axis of the four-section arm (4); the flat shaft (441) is provided with two mutually parallel positioning surfaces (4411); the waist-shaped sleeve (442) is provided with a waist-shaped hole (4421), and the waist-shaped sleeve (442) is fitted on the flat shaft (441), with the two positioning surfaces... The face (4411) abuts against the two side walls of the waist-shaped hole (4421). The flat shaft (441) and the waist-shaped hole (4421) have a gap along the common perpendicular direction of the axis of the flat shaft (441) and the rotation axis of the four-section arm (4). The waist hole sleeve (442) and the four-section arm (4) have a gap. The arm output end (4441) of the rotating arm (444) is located on the outside of the waist hole sleeve (442) through the joint bearing (443), and the arm input end (4442) is connected to the rotary driver. The rotary driver drives the input end (4442) of the drive arm to rotate, thereby driving the four-section arm (4) to rotate relative to the three-section arm (3) through the flat shaft (441).

2. The compact heavy-duty precision rotary mechanism according to claim 1, characterized in that, The four-section arm (4) has an installation cavity, and the flat shaft (441) and the rotary arm (444) are located in the installation cavity.

3. The compact heavy-duty precision rotary mechanism according to claim 2, characterized in that, The four-section arm (4) has two coaxial mounting holes (445), and a bushing (446) is fixed inside the mounting hole (445). The bushing (446) has a shaft hole in the center. The two ends of the flat shaft (441) are parallel to the plane of its axis and respectively abut against the plane of the shaft hole. The end of the flat shaft (441) is connected to a shaft cover (447) by screws, and the shaft cover (447) is pressed on the bushing (446).

4. A compact heavy-duty precision rotary mechanism according to any one of claims 1-3, characterized in that, The outer periphery of the waist hole sleeve (442) is provided with an outer boss (4422) and an outer retaining spring groove (4423). The inner ring of the spherical bearing (443) is sleeved on the waist hole sleeve (442) and abuts against the outer boss (4422). The spherical retaining spring (4424) is inserted into the outer retaining spring groove (4423) to restrict the axial movement of the inner ring of the spherical bearing (443). The arm output end (4441) is provided with a joint mounting hole (4444). The joint mounting hole (4444) is provided with an inner boss (4445) and an inner retaining spring groove (4446). The outer ring of the joint bearing (443) is located in the joint mounting hole (4444) and abuts against the inner boss (4445). The retaining spring (4447) is inserted into the inner retaining spring groove (4446) to restrict the axial movement of the outer ring of the joint bearing (443).

5. A compact, heavy-duty precision rotary mechanism according to claim 2, characterized in that, The four-section arm (4) and the three-section arm (3) are rotatably connected by a slewing bearing (45).

6. A compact, heavy-duty precision rotary mechanism according to claim 5, characterized in that, The four-section arm (4) is provided with a four-section arm flange (451), and the three-section arm (3) is provided with a three-section arm flange (452). The four-section arm flange (451) and the three-section arm flange (452) are respectively connected to the inner and outer rings of the slewing bearing (45).

7. A compact heavy-duty precision rotary mechanism according to claim 6, characterized in that, The three-section arm flange (452) is also fixedly connected to a reducer base (46). The reducer base (46) includes a housing (461), an upper flange (462), and a lower flange (463). The housing (461) is annular and its lower end extends through the four-section arm flange (451) into the mounting cavity of the four-section arm (4). The upper end of the housing (461) is coaxially fixed with the three-section arm flange (452) through the upper flange (462), and the lower end is connected to the rotary drive through the lower flange (463). The rotary drive passes through the housing (461).

8. A compact heavy-duty precision rotary mechanism according to claim 7, characterized in that, The rotary drive includes a motor (471) and a reducer (472). The housing of the reducer (472) is provided with a reducer flange (4721). The reducer flange (4721) is fixedly connected to the lower flange (463). The output end of the reducer (472) is fixedly connected to the arm input end (4442). The input end of the reducer (472) is connected to the motor (471).

9. A compact heavy-duty precision rotary mechanism according to claim 8, characterized in that, The reducer flange (4721) is located above the lower flange (463). A screw hole annular plate (473) is provided above the reducer flange (4721). The screw hole annular plate (473) has a threaded hole. After the screw passes through the lower flange (463) and the reducer flange (4721), it is screwed into the threaded hole on the screw hole annular plate (473). A lower operating port (448) is provided on the four-section arm (4). The lower operating port (448) is located below the four-section arm flange (451) and exposes the lower flange (463).

10. A compact, heavy-duty precision rotary mechanism according to claim 8, characterized in that, The rotary arm (444) includes an arm output end (4441), an arm input end (4442), and an arm inclined connecting section (4443). The arm output end (4441) is parallel to the arm input end (4442) and the arm output end (4441) is higher than the arm input end (4442). The arm inclined connecting section (4443) connects the arm input end (4442) and the arm output end (4441) at an inclination. The arm input end (4442) is provided with an input arm flange (4448), and the input arm flange (4448) is fixedly connected to the output end of the reducer (472).

Images