Lifting and rotating device and automatic weighing device

Abstract

The utility model discloses a kind of lifting rotary devices and automatic weighing devices, belong to analytical testing instrument technical field.Lifting rotary device includes fixed support, lifting device, rotary device and bearing frame.Lifting device includes lifting power mechanism, transmission mechanism, sliding sleeve and sliding limit sleeve lifted by transmission mechanism, rotary device includes rotary shaft and rotary power mechanism in the sleeve of sliding sleeve interior, rotary shaft can rotate relative to sliding sleeve and cannot be moved relative to axial direction, sliding sleeve lifts and drives rotary shaft to lift together;Bearing frame is fixed to the top of rotary shaft.The utility model bears guiding wear by sliding sleeve, thrust bearing carries gravity, reduce the stress and wear of rotary shaft, cooperate with sliding limit sleeve and slide rail to constitute double limit guide, lift steadily and reliably, effectively prolong the service life of rotary shaft.Automatic weighing device includes above-mentioned lifting rotary device, and automatic transfer of sample cup between sample holder and weighing instrument can be realized.

Description

Technical Field

[0001] This utility model relates to the field of analytical testing instrument technology, and more particularly to a lifting and rotating device, and an automatic weighing device including the lifting and rotating device. Specifically, this utility model relates to an automatic transfer technology for sample cups between a sample holder and a weighing instrument, and is particularly suitable for the transfer of sample cups in a drying method moisture analyzer. Background Technology

[0002] In the testing and analysis of solid materials such as coal, food, pharmaceuticals, and chemical products, automatic weighing of sample cups is a crucial step in the testing process. Especially in moisture content detection, the drying method (also known as the loss on drying method) is the most widely used and accurate classic measurement method. Its basic principle is to place the material to be tested in a sample cup, weigh the total mass of the sample cup and the material, then send the sample cup into a drying device for heating and drying to fully evaporate the moisture in the material. After drying, the mass of the sample cup and the material is weighed again, and the moisture content of the material is calculated by the difference in mass before and after drying.

[0003] With the increasing demand for testing and the continuous improvement of laboratory automation, automatic weighing devices and automatic drying weighing instruments have become important analytical equipment in fields such as coal quality analysis and food inspection. In these automatic weighing devices, the sample cups typically need to be transferred in an orderly manner between the sample rack (or weighing pan) and the weighing instrument to complete the weighing operation. In drying-based moisture analyzers, an automated testing process of "weighing-drying-re-weighing" is further required. Among these, the smoothness and reliability of the transfer operation of the sample cups between the sample rack and the weighing instrument are key factors affecting testing efficiency and the degree of automation.

[0004] Several automated devices for sample container transfer already exist in the prior art. For example, Chinese invention patent document CN112345775A discloses a reaction cup rotation and repositioning device, including a base, a lifting assembly, and a rotating assembly. The lifting assembly includes a lifting motor, a lead screw, and a lifting-rotating connecting plate, which drives the rotating assembly to reciprocate up and down. The rotating assembly includes a rotating motor and an eccentric mounting plate. The rotating motor drives the eccentric mounting plate to rotate around the motor shaft. A robotic arm mounting seat is eccentrically mounted on one side of the eccentric mounting plate. During rotation, the robotic arm and the reaction cup it holds move from one side to the other, realizing the transfer of the reaction cup between different positions. This device combines a lifting structure with a rotating structure, which can meet the requirement of the robotic arm to reposition the reaction cup to a designated position.

[0005] However, the aforementioned existing technologies and current conventional lifting and rotating devices still have the following shortcomings: First, in existing transfer devices, the rotating shaft typically only has a limiting structure at the end of the slider, lacking effective support and guiding restraint for the shaft itself. When the rotating shaft is subjected to eccentric torque and alternating loads from reciprocating lifting motion during long-term use, it is prone to bending deformation, leading to decreased transmission accuracy. In severe cases, this can even cause the device to jam or fail, directly affecting the equipment's service life and reliability. Even when support and guiding devices are provided for the rotating shaft, these devices are usually in direct contact with the shaft itself. During lifting, the rotating shaft directly contacts the guiding sliding structure, resulting in friction and wear. Because the rotating shaft bears both rotational and lifting motion simultaneously, its wear rate is relatively high. Once the rotating shaft wears out, it not only affects the guiding accuracy of the lifting motion but also reduces the coaxiality and stability of the rotational motion, resulting in high maintenance costs.

[0006] Secondly, in existing transfer devices, the weight of the rotating arm and the sample cup it carries acts directly on the rotating shaft. The rotating shaft not only has to bear the function of rotational drive, but also has to withstand axial gravity and radial off-center load for a long time. This stress state causes the rotating shaft to be under a large stress level for a long time, which accelerates the fatigue wear and deformation of the rotating shaft and further shortens the service life of the device.

[0007] To address the shortcomings of the existing technology, this application provides a lifting and rotating device and an automatic weighing device including the same. This lifting and rotating device can be widely used in various automatic weighing equipment requiring sample cup transfer, and is particularly suitable for the automated transfer of sample cups between the sample rack and the weighing instrument in a drying method moisture analyzer. Utility Model Content

[0008] (a) Technical problems to be solved This utility model provides a lifting and rotating device and an automatic weighing device including the same, aiming to solve at least one problem existing in the prior art. Specifically, the technical problems to be solved by this utility model include: First, in existing transfer devices, the rotating shaft is only provided with a limiting structure at the end of the slider. The shaft itself lacks effective support and guiding limit, and is prone to bending and deformation when subjected to eccentric torque and alternating load for a long time. Even if a shaft support structure is provided, the support and guiding device is in direct contact with the rotating shaft. The rotating shaft directly bears the guiding friction and wear during the lifting process. Since the rotating shaft bears the movement in both rotation and lifting directions at the same time, the wear rate is relatively fast. Once worn, it will affect the lifting and guiding accuracy and rotation coaxiality at the same time.

[0009] Second, in the existing transfer device, the weight of the rotating arm and the sample cup it carries directly acts on the rotating shaft. The rotating shaft not only has to bear the rotation drive function, but also has to bear the axial gravity and radial off-center load for a long time, which accelerates the fatigue wear and deformation of the rotating shaft.

[0010] (II) Technical Solution To solve the above-mentioned technical problems, this utility model provides a lifting and rotating device, including a fixed support, a lifting device, a rotating device, and a support frame.

[0011] The lifting device includes a lifting power mechanism, a lifting transmission mechanism connected to the lifting power mechanism, a sliding sleeve driven to move by the lifting transmission mechanism, and a sliding limiting sleeve for limiting the sliding direction of the sliding sleeve. The sliding limiting sleeve is fixedly connected to the fixed bracket, and the sliding sleeve is slidably disposed within the sliding limiting sleeve. Preferably, the sliding limiting sleeve is a linear bearing.

[0012] The rotating device includes a rotating shaft and a rotating power mechanism that is pulsatorically connected to the rotating shaft. The rotating shaft is sleeved inside the sliding sleeve, and the rotating shaft can rotate relative to the sliding sleeve but cannot move axially relative to the sliding sleeve. When the sliding sleeve rises or falls, it drives the rotating shaft to rise or fall together.

[0013] The support frame is fixedly connected to the top of the rotating shaft and is used to support the sample cup.

[0014] Furthermore, both ends of the rotating shaft are rotatably connected to the sliding sleeve via bearing one. The inner ring of bearing one is fixedly connected to the rotating shaft, and the outer ring of bearing one is fixedly connected to the sliding sleeve. A rotating shaft bracket is provided below the sliding sleeve, and the rotating shaft bracket is fixedly connected to the lower end of the sliding sleeve. The inner ring of bearing two is fixedly connected to the bottom end of the rotating shaft, and the outer ring of bearing two is fixedly installed on the rotating shaft bracket.

[0015] Furthermore, the rotary power mechanism is fixedly connected to the rotary shaft bracket, and the rotary power mechanism is a rotary power motor. The output end of the rotary power motor is connected to the rotary shaft via a belt drive.

[0016] Furthermore, the top of the sliding sleeve is connected to the support frame via a thrust bearing, which is used to bear the weight of the support frame and the items it carries. There is a gap between the thrust bearing and the rotating shaft so as not to affect the rotation of the rotating shaft.

[0017] Furthermore, the support frame is elongated, and a cup holder for placing the sample cup is provided at one end of the support frame away from the rotation axis. The edge of the cup holder is provided with a limiting protrusion, which is used to limit the horizontal position of the sample cup on the cup holder.

[0018] Furthermore, the lifting transmission mechanism includes a lead screw, a slider, and a slide rail. The lead screw is arranged vertically and is rotatably connected to the fixed bracket via a bearing. The lead screw is connected to the output end of the lifting power mechanism. The slider is threadedly connected to the lead screw and is fixedly connected to the sliding sleeve. The slide rail is arranged parallel to the lead screw, and the slider is slidably connected to the slide rail, which is fixed to the fixed bracket.

[0019] Furthermore, the slider is fixedly connected to a pull wire of a pull wire encoder, which is used to detect the lifting position of the slider; the rotating shaft is connected to a rotary encoder, which is used to detect the rotation angle of the rotating shaft.

[0020] Furthermore, the sliding sleeve includes a sliding sleeve body and sliding sleeve caps fixedly connected to both ends of the sliding sleeve body.

[0021] This utility model also provides an automatic weighing device, including a sample rack for carrying a sample cup, a weighing instrument for weighing the sample cup, and a lifting and rotating device as described in any of the above technical solutions. The lifting and rotating device is disposed between the sample rack and the weighing instrument, and is used to reciprocate the sample cup between the sample rack and the weighing instrument.

[0022] (III) Beneficial Effects Compared with the prior art, this utility model has the following advantages: First, it significantly extends the service life of the rotating shaft. This invention, by fitting the rotating shaft inside the sliding sleeve, allows the sliding sleeve to drive the rotating shaft to rise and fall together. During the rising and falling process, the rotating shaft does not directly contact the sliding limit sleeve. The friction and wear during the sliding guidance process are borne by the sliding sleeve. The rotating shaft does not need to directly bear the guiding wear, effectively avoiding the decrease in accuracy and shortened life of the rotating shaft due to guiding friction.

[0023] Secondly, the load on the rotating shaft is significantly reduced. This invention connects the support frame to the top of the sliding sleeve via a thrust bearing, so that the weight of the support frame and the sample cup it carries is mainly borne by the sliding sleeve. This significantly reduces the axial force transmitted to the rotating shaft, allowing it to primarily perform the function of rotational drive. The stress state is greatly improved, further extending the service life of the rotating shaft.

[0024] Third, a dual-limiting and guiding system is formed, making the lifting and lowering movement more stable and reliable. This utility model sets a sliding limit sleeve on the outside of the rotating shaft, and a slide rail limit structure at the slider. Together, they form a dual-limiting and guiding system, which provides support and limit for the lifting and lowering movement of the sliding sleeve and the rotating shaft throughout the axial range, effectively preventing the rotating shaft from bending and deforming due to long-term eccentric load.

[0025] Fourth, the transmission accuracy is higher. This utility model uses a wire encoder and a rotary encoder, which can achieve precise positioning during lifting and rotation processes.

[0026] Fifth, the support is more stable. Compared with the rotating shaft, the outer diameter of the sliding sleeve of this utility model is larger, which makes the support of the bearing frame and the sample cup more stable and effectively improves the stability during the transfer of the sample cup. Attached Figure Description

[0027] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0028] Figure 1 This is a schematic diagram of the lifting and rotating device in the embodiment; Figure 2 This is a partial cross-sectional view of the lifting and rotating device in the embodiment; Figure 3 This is a schematic diagram of the encoder structure in the embodiment; Figure 4 This is a schematic diagram of the automatic weighing device in the embodiment; Figure 5 This is a schematic diagram of the structure of the support frame and sample holder in the embodiment; Figure 6 This is a schematic diagram illustrating the placement of the sample cup on the weighing instrument by the cup holder in this embodiment; The meanings of the labels in the figures are as follows: Fixed bracket and related components 1—Fixed bracket; Lifting device and related components 2—Lifting device; 21—Lifting power mechanism; 22—Lifting transmission mechanism; 22a—Lead screw; 22b—Bearing 3; 22c—Slide rail; 22d—Slider; 23—Sliding sleeve; 23a—Sliding sleeve body; 23b—Sliding sleeve cap; 24—Sliding limit sleeve; 25—Thrust bearing; Rotating device and related components 3—Rotating device; 31—Rotating shaft; 32—Rotating shaft bracket; 33—Rotating power mechanism; 34—Bearing 2; 35—Bearing 1; Support frame and related components 4—Support frame; 41—Cup holder; 42—Limiting protrusion; Detection element 5—Wire encoder; 6—Rotary encoder; Components of automatic weighing device 7—Sample rack; 8—Weighing instrument. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0030] In the description of this utility model, it should be understood that the terms "upper," "lower," "top," "bottom," "vertical," and "horizontal," 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 utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. The terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0031] It should be noted that the following embodiments are all specific elaborations of different aspects under the same technical concept of this utility model. The embodiments complement and support each other, rather than being parallel solutions that replace each other. Embodiment 1 describes the overall structure of the lifting and rotating device of this utility model, constituting the basic implementation of this utility model; Embodiment 2 further refines the assembly relationship between the sliding sleeve and the rotating shaft, providing an in-depth explanation of the core inventive point of this utility model; Embodiment 3 adds an implementation scheme for a position detection device to improve the automatic control accuracy of the device; Embodiment 4 applies the lifting and rotating device to an automatic weighing device, demonstrating the system-level implementation of this utility model; Embodiment 5 further describes the application of the automatic weighing device to an automatic drying weighing device; Embodiment 6 specifically describes the double-limiting guide structure to further highlight the improvement of this utility model in terms of guiding stability. Those skilled in the art should understand that the technical features in the above embodiments can be combined with each other without contradiction to form more implementation methods, all of which fall within the protection scope of this utility model.

[0032] Example 1: Overall Structure of the Lifting and Rotating Device like Figure 1 As shown, this utility model provides a lifting and rotating device, including a fixed bracket 1, a lifting device 2, a rotating device 3, and a support frame 4.

[0033] The fixed bracket 1 serves as the mounting base for the lifting and rotating device of this utility model, used to fix and support the various components of the lifting device 2 and the rotating device 3. The fixed bracket 1 can be made of metal materials (such as aluminum alloy or stainless steel) and has sufficient structural strength and rigidity to ensure the stability and reliability of the device during long-term operation.

[0034] like Figure 1 and Figure 2 As shown, the lifting device 2 includes a lifting power mechanism 21, a lifting transmission mechanism 22, a sliding sleeve 23, and a sliding limit sleeve 24. The lifting power mechanism 21 is fixedly mounted on the fixed bracket 1. In this embodiment, the lifting power mechanism 21 is a lifting power motor, preferably a servo motor, to facilitate precise control of the lifting stroke and speed. The output end of the lifting power motor is connected to the lifting transmission mechanism 22.

[0035] like Figure 2 As shown, the lifting transmission mechanism 22 includes a lead screw 22a, a slider 22d, and a slide rail 22c. The lead screw 22a is arranged vertically and is rotatably connected to the fixed bracket 1 via a bearing 22b. The lower end of the lead screw 22a is connected to the output end of the lifting power motor. The lead screw 22a rotates around its own axis under the drive of the lifting power motor. The slider 22d has an internal thread that mates with the lead screw 22a, and the slider 22d is threadedly fitted onto the lead screw 22a. The slide rail 22c is arranged parallel to the lead screw 22a and is fixed to the fixed bracket 1. The slider 22d is slidably connected to the slide rail 22c. When the lead screw 22a rotates, it drives the slider 22d to move up and down along the axial direction (i.e., the vertical direction) of the lead screw 22a. The slide rail 22c guides and limits the up and down movement of the slider 22d, ensuring the linearity and smoothness of the up and down movement.

[0036] The sliding sleeve 23 is fixedly connected to the slider 22d and rises and falls together with the slider 22d. The sliding sleeve 23 has a hollow cylindrical structure and is arranged vertically. In this embodiment, as shown... Figure 4 As shown, the sliding sleeve 23 includes a sliding sleeve body 23a and sliding sleeve caps 23b fixedly connected to both ends of the sliding sleeve body 23a. The sliding sleeve body 23a has a cylindrical structure with a through hole along the axial direction inside to accommodate the rotating shaft 31. The sliding sleeve caps 23b are fixedly connected to the upper and lower ends of the sliding sleeve body 23a.

[0037] The sliding limit sleeve 24 is fixedly connected to the fixed bracket 1, and the sliding sleeve 23 is slidably disposed within the sliding limit sleeve 24. In this embodiment, the sliding limit sleeve 24 is a linear bearing. The inner wall of the linear bearing is provided with several rows of balls or rollers. When the sliding sleeve 23 slides axially within the linear bearing, the balls or rollers roll between the outer wall of the sliding sleeve 23 and the inner wall of the linear bearing, converting sliding friction into rolling friction. This greatly reduces the frictional resistance of the lifting and lowering movement of the sliding sleeve 23, while improving the guiding accuracy and stability of the lifting and lowering movement. The outer diameter of the sliding sleeve 23 is adapted to the inner diameter of the linear bearing, allowing the sliding sleeve 23 to slide freely axially within the linear bearing without radial displacement.

[0038] like Figure 1 and Figure 2 As shown, the rotating device 3 includes a rotating shaft 31 and a rotating power mechanism 33. The rotating shaft 31 is arranged vertically and is fitted inside the sliding sleeve 23. Specifically, the rotating shaft 31 passes through a through hole inside the sliding sleeve body 23a, and its two ends extend from the two ends of the sliding sleeve 23. The rotating shaft 31 can rotate relative to the sliding sleeve 23, but cannot move axially relative to the sliding sleeve 23. To achieve the above function, the two ends of the rotating shaft 31 are rotatably connected to the sliding sleeve 23 through bearings 35. The inner ring of the bearing 35 is fixedly connected to the outer wall of the rotating shaft 31, and the outer ring of the bearing 35 is fixedly connected to the inner wall of the sliding sleeve 23 (specifically, the inner wall of the sliding sleeve cap 23b). In this embodiment, the bearing 35 is preferably an angular contact ball bearing capable of simultaneously withstanding axial and radial forces. Angular contact ball bearings have good radial and axial load-bearing capacity, ensuring smooth rotation of the rotating shaft 31 within the sliding sleeve 23 while limiting the axial displacement of the rotating shaft 31 relative to the sliding sleeve 23, thus maintaining a fixed axial connection between the rotating shaft 31 and the sliding sleeve 23. When the sliding sleeve 23 rises and falls with the slider 22d, it drives the rotating shaft 31 to rise and fall together.

[0039] like Figure 2 As shown, a rotating shaft bracket 32 ​​is provided below the sliding sleeve 23. The rotating shaft bracket 32 ​​is fixedly connected to the lower end of the sliding sleeve 23. In this embodiment, the rotating shaft bracket 32 ​​is a plate-shaped structure, horizontally arranged, with one end fixedly connected to the lower outer wall of the sliding sleeve 23, and the other end extending outward in a horizontal direction. The outer ring of the second bearing 34 is fixedly installed on the rotating shaft bracket 32, and the inner ring of the second bearing 34 is fixedly connected to the bottom end of the rotating shaft 31. The second bearing 34 is used to provide radial support for the lower end of the rotating shaft 31, reducing the shaking of the rotating shaft 31 during rotation and lifting, and further improving the motion stability of the rotating shaft 31.

[0040] The rotary power mechanism 33 is fixedly connected to the rotary shaft bracket 32. In this embodiment, the rotary power mechanism 33 is a rotary power motor, preferably a servo motor. The output end of the rotary power motor is connected to the rotary shaft 31 via a belt drive. Specifically, a driven pulley is fixedly connected to the lower end of the rotary shaft 31, and a driving pulley is fixedly connected to the output shaft of the rotary power motor. The driving pulley and the driven pulley are connected by a transmission belt. When the rotary power motor rotates, it transmits power to the rotary shaft 31 through the driving pulley, the transmission belt, and the driven pulley, driving the rotary shaft 31 to rotate around its own axis. The belt drive method has advantages such as smooth transmission, low noise, and overload protection, which helps to improve the service life and operational reliability of the device.

[0041] The support frame 4 is fixedly connected to the top of the rotating shaft 31. In this embodiment, the support frame 4 is a long strip-shaped plate structure, with one end fixedly connected to the top of the rotating shaft 31 and the other end extending outward in a horizontal direction. The support frame 4 rises, falls, and rotates together with the rotating shaft 31.

[0042] like Figure 5 As shown, a cup holder 41 is provided at the end of the support frame 4 away from the rotation axis 31 (i.e., the free end), which is used to place the sample cup. The shape of the cup holder 41 is adapted to the bottom shape of the sample cup, and is generally a circular structure, so that the sample cup can be placed on the cup holder 41. The edge of the cup holder 41 is provided with limiting protrusions 42, which are used to limit the horizontal position of the sample cup on the cup holder 41 and prevent the sample cup from slipping off the cup holder 41 due to inertia or vibration during the transfer process. In this embodiment, the limiting protrusions 42 are multiple arc-shaped protrusions spaced apart along the edge of the cup holder 41. The arc-shaped protrusions together form a receiving space adapted to the outer diameter of the bottom of the sample cup, which can both limit the horizontal position of the sample cup and facilitate the picking and placing of the sample cup.

[0043] Example 2: Assembly relationship between the sliding sleeve and the rotating shaft Example 2, based on Example 1, further refines the assembly relationship between the sliding sleeve and the rotating shaft, providing an in-depth explanation of the core inventive points of this utility model; for example... Figure 2 The diagram shown is a cross-sectional view of the assembly relationship between the sliding sleeve 23 and the rotating shaft 31 in the lifting and rotating device of this utility model.

[0044] The sliding sleeve 23 includes a sliding sleeve body 23a and a sliding sleeve cap 23b. The sliding sleeve body 23a has a cylindrical structure with a through hole running through it along the axial direction. There are two sliding sleeve caps 23b, which are fixedly connected to the upper and lower ends of the sliding sleeve body 23a, respectively. The sliding sleeve cap 23b is annular, and its inner diameter is larger than the outer diameter of the rotating shaft 31.

[0045] The rotating shaft 31 passes through a through hole inside the sliding sleeve body 23a, with both ends of the rotating shaft 31 extending from the upper and lower sliding sleeve caps 23b, respectively. After the upper end of the rotating shaft 31 extends from the upper end of the sliding sleeve 23, it is fixedly connected to the support frame 4. After the lower end of the rotating shaft 31 extends from the lower end of the sliding sleeve 23, it is fixedly connected to the inner ring of the bearing 34.

[0046] The upper end of the rotating shaft 31 is rotatably connected to the upper sliding sleeve cap 23b via bearing 35, and the lower end of the rotating shaft 31 is rotatably connected to the lower sliding sleeve cap 23b via bearing 35. Bearing 35 is an angular contact ball bearing, with its inner ring fixedly connected to the outer wall of the rotating shaft 31 via an interference fit, and its outer ring fixedly connected to the inner wall of the sliding sleeve cap 23b via an interference fit. The two bearings 35 are respectively located at both ends of the rotating shaft 31, which allows the rotating shaft 31 to rotate freely within the sliding sleeve 23, and fixes the rotating shaft 31 axially to the sliding sleeve 23, preventing the rotating shaft 31 from moving axially relative to the sliding sleeve 23. When the sliding sleeve 23 is raised and lowered by the lifting transmission mechanism 22, the two bearings 35 drive the rotating shaft 31 to rise and fall synchronously.

[0047] In this embodiment, the outer diameter of the sliding sleeve 23 is larger than the outer diameter of the rotating shaft 31. The outer wall of the sliding sleeve 23 slides in contact with the inner wall of the sliding limit sleeve 24 (linear bearing), bearing all the friction and wear during the lifting and guiding process. The rotating shaft 31 does not need to directly contact any guiding structure, thereby avoiding wear caused by guiding friction on the rotating shaft 31 and effectively extending the service life of the rotating shaft 31.

[0048] like Figure 2 and Figure 4 As shown, the top of the sliding sleeve 23 (i.e., the upper end face of the upper sliding sleeve cap 23b) is connected to the support frame 4 via a thrust bearing 25. The thrust bearing 25 is disposed between the top of the sliding sleeve 23 and the lower surface of the support frame 4. The lower ring of the thrust bearing 25 is fixedly connected to the top of the sliding sleeve 23, and the upper ring of the thrust bearing 25 is fixedly connected to the lower surface of the support frame 4. The thrust bearing 25 is used to bear the gravitational load of the support frame 4 and the sample cup it carries. When the support frame 4 and the sample cup on it are subjected to gravity, the gravity is transmitted to the sliding sleeve 23 through the thrust bearing 25, and then from the sliding sleeve 23 to the slider 22d and the fixed bracket 1, without directly acting on the rotating shaft 31. There is a gap between the thrust bearing 25 and the rotating shaft 31, that is, there is a small gap between the inner ring of the thrust bearing 25 and the outer wall of the rotating shaft 31, and the two do not contact each other. Therefore, the gravitational load borne by the thrust bearing 25 is not transmitted to the rotating shaft 31 and does not affect the rotation of the rotating shaft 31.

[0049] Through the above structural design, the rotating shaft 31 mainly undertakes the function of rotation drive, without having to bear axial gravity and radial off-center load for a long time. The stress state is greatly improved, thereby significantly extending the service life of the rotating shaft 31.

[0050] Example 3: Position Detection Device like Figure 3 As shown, the lifting and rotating device of this utility model is also equipped with a position detection device, which is used to detect the lifting position of the sliding sleeve 23 and the rotation angle of the rotating shaft 31 in real time.

[0051] The slider 22d is fixedly connected to the pull wire of the pull wire encoder 5. The housing of the pull wire encoder 5 is fixedly mounted on the fixed bracket 1, and the end of the pull wire of the pull wire encoder 5 is fixedly connected to the slider 22d. When the slider 22d rises or falls, it drives the pull wire of the pull wire encoder 5 to extend or retract. The pull wire encoder 5 detects the rising or falling position of the slider 22d in real time according to the extension length of the pull wire and feeds the position signal back to the control unit, thereby realizing precise control of the rising or falling position.

[0052] A rotary encoder 6 is connected to the rotating shaft 31. In this embodiment, the housing of the rotary encoder 6 is fixedly mounted on the rotating shaft bracket 32, and its rotating shaft is fixedly connected to the lower end of the rotating shaft 31. When the rotating shaft 31 rotates, it drives the rotating shaft of the rotary encoder 6 to rotate synchronously. The rotary encoder 6 detects the rotation angle of the rotating shaft 31 in real time according to the rotation angle of the rotating shaft and feeds the angle signal back to the control unit, thereby realizing precise control of the rotation angle.

[0053] By setting up a wire encoder 5 and a rotary encoder 6, the lifting and rotating device of this invention can realize closed-loop control of the lifting position and rotation angle, ensuring the accuracy and repeatability of the transfer of the sample cup between the sample holder 7 and the weighing instrument 8.

[0054] Example 4: Automatic Weighing Device like Figures 4-6 As shown, this utility model also provides an automatic weighing device, including a sample rack 7, a weighing instrument 8, and the lifting and rotating device described in any of the above embodiments.

[0055] The sample holder 7 is used to support the sample cups. In this embodiment, the sample holder 7 has a disc-shaped structure with multiple cup holes evenly spaced along the circumference for placing the sample cups. The sample holder 7 can be driven to rotate by a servo motor to switch between different sample cups.

[0056] The weighing instrument 8 is used to weigh the sample cup. In this embodiment, the weighing instrument 8 is an electronic balance with high precision and high resolution, capable of accurately weighing the sample cup and its contents.

[0057] A lifting and rotating device is located between the sample holder 7 and the weighing instrument 8, used to reciprocate the sample cup between the sample holder 7 and the weighing instrument 8. Specifically, the lifting and rotating device is located on one side of the sample holder 7, and the cup seat 41 of the support frame 4 can rotate and switch between above the sample holder 7 and above the weighing instrument 8 under the drive of the rotating shaft 31.

[0058] The working process of the lifting and rotating device in this embodiment will be described in detail below with reference to the accompanying drawings.

[0059] In the initial state, the support frame 4 of the lifting and rotating device is located in the middle position between the sample holder 7 and the weighing instrument 8, and the sliding sleeve 23 is located in the middle position or the lower limit position of its lifting stroke.

[0060] When it is necessary to transfer the sample cup from the sample holder 7 to the weighing instrument 8, the control unit first controls the rotary motor to start. The rotary motor drives the rotary shaft 31 to rotate via belt drive. The rotary shaft 31 drives the support frame 4 to rotate, causing the cup holder 41 at the free end of the support frame 4 to rotate directly below the sample holder 7. During this process, the rotary encoder 6 detects the rotation angle of the rotary shaft 31 in real time. When the rotary shaft 31 rotates to the preset angle, the control unit controls the rotary motor to stop rotating.

[0061] Then, the control unit starts the lifting motor, which drives the lead screw 22a to rotate. The lead screw 22a drives the slider 22d to slide upward along the slide rail 22c. The slider 22d drives the sliding sleeve 23 to slide upward along the sliding limit sleeve 24 (linear bearing). The sliding sleeve 23 drives the rotating shaft 31 to rise synchronously through the bearing 35. The rotating shaft 31 drives the support frame 4 to rise synchronously. During the rise of the support frame 4, the cup holder 41 lifts the sample cup placed on the sample holder 7 from below until the sample cup is completely detached from the sample holder 7. The sample holder 7 is provided with a notch for the cup holder 41 to pass through vertically. During this process, the wire encoder 5 detects the lifting position of the slider 22d in real time. When the slider 22d rises to the preset height, the control unit controls the lifting motor to stop rotating.

[0062] Next, the control unit restarts the rotary motor, which drives the rotating shaft 31 to rotate. The rotating shaft 31 then rotates the support frame 4, which carries the sample cup from directly above the sample holder 7 to directly above the weighing instrument 8. During this process, the rotary encoder 6 monitors the rotation angle of the rotating shaft 31 in real time. When the rotating shaft 31 reaches the preset angle, the control unit stops the rotary motor.

[0063] Finally, the control unit controls the lifting motor to start in reverse, driving the lead screw 22a to rotate in the opposite direction. The lead screw 22a drives the slider 22d to slide downwards along the slide rail 22c. The slider 22d drives the sliding sleeve 23 to slide downwards along the sliding limit sleeve 24. The sliding sleeve 23 drives the rotating shaft 31 to descend synchronously through the bearing 35. The rotating shaft 31 drives the support frame 4 to descend synchronously. During the descent of the support frame 4, the cup holder 41 places the sample cup on the weighing platform of the weighing instrument 8. The cup holder 41 continues to descend until it detaches from the sample cup. During this process, the wire encoder 5 monitors the lifting position of the slider 22d in real time. When the slider 22d descends to the preset height, the control unit controls the lifting motor to stop rotating.

[0064] This completes the transfer process of the sample cup from the sample holder 7 to the weighing instrument 8. When it is necessary to transfer the sample cup back from the weighing instrument 8 to the sample holder 7, simply repeat the above steps in reverse order.

[0065] By repeatedly executing the above transfer process, the lifting and rotating device of this invention can realize the continuous reciprocating transfer of the sample cup between the sample holder 7 and the weighing instrument 8, thus meeting the requirements of the automated operation of the automatic weighing device.

[0066] Example 5: Automatic Drying and Weighing Device In this embodiment, the automatic drying and weighing device includes the automatic weighing device and drying device (not shown in the figure) from Embodiment 4. The drying device is used to heat and dry the sample in the sample cup. The drying device can be set above or below the sample holder 7, or at other suitable locations on the automatic weighing device. In the moisture determination by drying method, the sample cup is first weighed on the weighing instrument 8 to obtain an initial mass, then transferred to the sample holder 7 by the lifting and rotating device, and then sent to the drying device by the sample holder 7 for drying. After drying, it is transferred back to the weighing instrument 8 by the lifting and rotating device for weighing. The moisture content of the material is calculated by the mass difference before and after drying.

[0067] Example 6: Dual-limiting guide structure In this utility model, the sliding limiting sleeve 24 is fixedly connected to the fixed bracket 1, and its inner wall slides in cooperation with the outer wall of the sliding sleeve 23 to guide and limit the lifting and lowering movement of the sliding sleeve 23 throughout the process, preventing the sliding sleeve 23 from radially shifting or shaking during the lifting and lowering process. This is the first level of limiting and guiding.

[0068] Meanwhile, the slider 22d is slidably connected to the slide rail 22c, which is fixed on the fixed bracket 1 to guide and limit the lifting and lowering movement of the slider 22d. This is the second level of limiting and guiding.

[0069] Through the aforementioned dual limiting and guiding system, the lifting and lowering movements of the sliding sleeve 23 and the rotating shaft 31 are supported and limited throughout the axial range, effectively preventing the rotating shaft 31 from bending and deforming due to long-term bearing of eccentric torque and alternating load, and significantly improving the smoothness and reliability of the lifting and lowering movements.

[0070] In addition, the outer diameter of the sliding sleeve 23 is larger than the outer diameter of the rotating shaft 31. The sliding fit area between the sliding limit sleeve 24 and the sliding sleeve 23 is large and the contact stiffness is high, which makes the support of the bearing frame 4 and the sample cup more stable and further improves the stability and positioning accuracy during the sample cup transfer process.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A lifting and rotating device, characterized in that, include: Fixed bracket (1); The lifting device (2) includes a lifting power mechanism (21), a lifting transmission mechanism (22) connected to the lifting power mechanism (21), a sliding sleeve (23) driven to lift by the lifting transmission mechanism (22), and a sliding limit sleeve (24) for limiting the sliding direction of the sliding sleeve (23). The sliding limit sleeve (24) is fixedly connected to the fixed bracket (1), and the sliding sleeve (23) is slidably disposed in the sliding limit sleeve (24). The rotating device (3) includes a rotating shaft (31) and a rotating power mechanism (33) that is drivenly connected to the rotating shaft (31). The rotating shaft (31) is sleeved inside the sliding sleeve (23). The rotating shaft (31) can rotate relative to the sliding sleeve (23) but cannot move axially relative to the sliding sleeve (23). When the sliding sleeve (23) rises and falls, it drives the rotating shaft (31) to rise and fall together. The support frame (4) is fixedly connected to the top of the rotating shaft (31).

2. The lifting and rotating device according to claim 1, characterized in that, The two ends of the rotating shaft (31) are rotatably connected to the sliding sleeve (23) through bearing one (35). The inner ring of the bearing one (35) is fixedly connected to the rotating shaft (31), and the outer ring of the bearing one (35) is fixedly connected to the sliding sleeve (23). A rotating shaft bracket (32) is provided below the sliding sleeve (23), and the rotating shaft bracket (32) is fixedly connected to the lower end of the sliding sleeve (23); the bottom end of the rotating shaft (31) is fixedly connected to the inner ring of the bearing second (34), and the outer ring of the bearing second (34) is fixedly installed on the rotating shaft bracket (32).

3. The lifting and rotating device according to claim 2, characterized in that, The rotary power mechanism (33) is fixedly connected to the rotary shaft bracket (32). The rotary power mechanism (33) is a rotary power motor. The output end of the rotary power motor is connected to the rotary shaft (31) via belt drive. The lifting power mechanism (21) is a lifting power motor.

4. The lifting and rotating device according to claim 1, characterized in that, The top of the sliding sleeve (23) is connected to the support frame (4) via a thrust bearing (25). The thrust bearing (25) is used to bear the weight of the support frame (4) and the items it carries. There is a gap between the thrust bearing (25) and the rotating shaft (31) so as not to affect the rotation of the rotating shaft (31).

5. The lifting and rotating device according to claim 1, characterized in that, The support frame (4) is long and narrow. One end of the support frame (4) away from the rotation axis (31) is provided with a cup holder (41) for placing the sample cup. The edge of the cup holder (41) is provided with a limiting protrusion (42). The limiting protrusion (42) is used to limit the horizontal position of the sample cup on the cup holder (41).

6. The lifting and rotating device according to claim 1, characterized in that, The lifting transmission mechanism (22) includes: A lead screw (22a) is arranged in a vertical direction. The lead screw (22a) is rotatably connected to the fixed bracket (1) through a bearing three (22b). The lead screw (22a) is connected to the output end of the lifting power mechanism (21). The slider (22d) is threadedly connected to the lead screw (22a), and the slider (22d) is fixedly connected to the sliding sleeve (23). The slide rail (22c) is arranged parallel to the lead screw (22a), the slider (22d) is slidably connected to the slide rail (22c), and the slide rail (22c) is fixed to the fixed bracket (1). The sliding limit sleeve (24) is a linear bearing.

7. The lifting and rotating device according to claim 6, characterized in that, The slider (22d) is fixedly connected to the pull wire of the pull wire encoder (5), which is used to detect the lifting position of the slider (22d); The rotating shaft (31) is connected to a rotary encoder (6), which is used to detect the rotation angle of the rotating shaft (31).

8. The lifting and rotating device according to claim 1, characterized in that, The sliding sleeve (23) includes a sliding sleeve body (23a) and sliding sleeve caps (23b) fixedly connected to both ends of the sliding sleeve body (23a).

9. An automatic weighing device, characterized in that, include: The sample holder (7) is used to support the sample cup; Weighing instrument (8) is used to weigh the sample cup; And the lifting and rotating device according to any one of claims 1 to 8; The lifting and rotating device is located between the sample holder (7) and the weighing instrument (8) and is used to transfer the sample cup back and forth between the sample holder (7) and the weighing instrument (8).

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