Keywords: biochemical analysis, sample adding system, linear motion, linear stepper motor,
introduction
Biochemical analyzer is one of the important instruments commonly used in clinical diagnosis. With the advancement of medical science, biochemical analyzers are manually operated to enter the mechanization and automation stages. The automatic biochemical analyzer has the advantages of high precision, good repeatability, complete functions, and many test items, as well as rapid, simple, trace, etc., and has been widely used in laboratory and clinical inspection. At present, in the domestic market of automatic biochemical analyzers, although domestic brands are catching up, they are still dominated by foreign products. The main reason is that domestic brands still have a certain gap between reliability and automation. The linear stepper motor is a patented technology product that is applied to the automatic biochemical analyzer sample adding system and it is different from the traditional transmission method. It can achieve accurate sample loading and automatic loading while ensuring high system lifetime and high reliability. .
Application of Linear Stepper Motor in Automatic Biochemistry Analyzer
The automatic biochemical analyzer is an instrument for automatic operation of clinical biochemical analysis such as sampling, adding reagents, interference elimination, mixing, heat preservation reaction, detection, data processing, result display and output, and cleaning and other experimental operation steps.
The automatic sampling and sampling functions of the automatic biochemical analyzer are realized through its sample adding system. The mechanical actuators in the sample loading system generally include a cantilever mechanism and a drive mechanism. The current domestic drive mechanism generally uses rotary stepping motors and transmission mechanisms such as: timing belts, racks, ball screws, and the like; the transmission mechanism is connected with a cantilever mechanism so as to realize an automatic sampling and sampling function. The disadvantage of the ball screw is its large size and high cost. It requires high adjustment of the mechanism, and the ball screw generally has a large pitch, resulting in low resolution of the mechanism. The disadvantage of other transmission methods is that the accuracy is not high, and then the noise is relatively large, the most critical is that the life can not be guaranteed, thus affecting the overall quality and grade of the product, and is in a disadvantageous position in competition with similar foreign products.
Fig. 1 The structure of traditional transmission is complex and the overall cost is high
The linear stepper motor realizes accurate sample loading and automatic loading of the automatic biochemical analyzer while compensating for the above defects with its high accuracy and high reliability.
The following figure shows the typical application of a linear stepper motor in a sampler arm of a biochemical analyzer
Figure 2 linear stepper motor structure is simple, easy overall design
Since the linear stepping realizes the conversion from the rotary motion to the linear motion within the motor, the cantilever mechanism is directly connected with the motor, so that the mechanism is as compact and concise as possible, and the mechanical mechanism of the intermediate transmission link is not required to make it more accurate. Higher efficiency and longer life.
More concise: The structural characteristics of the linear stepper motor make it easy to use. In fact, the reason why linear stepping motors have such successful applications in the field of automatic biochemical analysis is that their simplicity, accuracy, and sensitivity and high reliability perfectly match the performance requirements of linear motion control for automatic biochemical analyzers.
More high precision: The linear stepper motor adopts Acme screw drive, and the screw is rolled at a time. The transmission accuracy can be made 0.0005mm/mm, and the highest resolution can reach 0.0015mm. In addition, in order to achieve higher accuracy, anti-backlash nut can be equipped, which can eliminate backlash and achieve higher transmission accuracy.
Higher efficiency: Compared with the transmission mechanism commonly used in automatic biochemical analyzers such as rack and pinion drive or synchronous belt drive, linear stepper motors undoubtedly have higher transmission efficiency. The first is that its Acme screw has a 29-degree profile angle efficiency compared to a normal V-thread, and because it is designed for transmission, surface finish, pitch accuracy, and tolerances are not comparable to V-threads.
Figure 3 Comparison of Acme and V-threads
Higher life: Due to the patented structural design as a linear stepper motor (Patent No. China ZL200330102644.4, US 6.932,319), as well as specialized linear drive manufacturing process to ensure the high life of the overall mechanism, in addition to its self-lubricating nut material and High-quality screw processing technology also provides high life guarantee. In fact, the motor can reach a life of at least 5 million cycles under normal load conditions.
Linear stepper motor technology
The stepping motor is generated by the magnetic rotor core interacting with the pulsed electromagnetic field generated by the stator, and the linear stepping motor converts the rotational motion into a linear motion within the motor. The linear stepper motor, or linear stepper motor, first appeared in the United States Patent No. 3,402,308 of 1968 and was issued to William Henschke. Since then, linear stepper motors have been widely used to manufacture, Precision calibration, precision fluid measurement, accurate position shifting, and many other high-precision requirements.
The basic principle of the linear stepping motor is to use a screw and nut meshing, take some way to prevent the relative rotation of the screw nut, so that the screw moves axially. In general, there are currently two ways to achieve this transformation. The first is to have a rotor with internal threads in the motor, with the internal thread of the rotor meshing with the screw for linear motion, and the second with the screw as The output shaft of the motor is externally engaged with the screw through an external drive nut to achieve linear motion. The result of this is that the design is greatly simplified, making it possible to use linear stepper motors for precise linear motion directly without installing external mechanical linkages in many applications.
Figure 4 A typical fixed-axis linear stepper motor schematic
Compared with the screw, the nut of the drive screw is even more important. The linear stepper motor uses a bronze injection molded internal thread rotor. This patented product integrates physical stability and lubrication performance, while having a low coefficient of friction. There is also a very good thermal expansion performance. The excellent performance of both ensures the long life of the linear stepper motor. The following figure shows the life curve of the motor based on the bronze material.
Figure 5 motor life curve
The successful application of linear stepper motor in China
At present, there are not many manufacturers specializing in the production of linear stepper motors in China. Yamashiro Motors is the agent responsible for quality assurance of Yamashiro Linear Motors. Since its establishment, the company has always been committed to optimizing the linear motion solutions of customers and improving the performance of customers' products. Especially in the field of biochemical analysis, Yamashiro Motors is praised by its customers for its outstanding cost performance, good after-sales service and strong technical support. At the same time, Haydn customization products are completely customized for biochemical analyzers, which provides design engineers with more room for design and provides customers with good preconditions for improving the overall performance of their products. The concise, maintenance-free, and long-life features of Haydn's motors enable them to be quickly accepted in the field of biochemical analysis because of their lower overall cost. The excellent performance has made them widely recognized and praised in applications. Haydn has always been praised for its praise. After-sales service makes it continue to forge ahead in the market.
Shanshe Motors has taken root in the Chinese market for more than three years and has quickly occupied the market share of related application fields with absolute advantages. It has established good cooperative relations with many well-known manufacturers at home and abroad, such as Shenzhen Mike and Nanjing Huanuohua. In addition, Shanshe Motor has established long-term cooperation with famous universities and research institutes in China, and has made its own contributions to the promotion of domestic industry progress.
Chaff Cutter,Chaff Cutter Machine,Mini Chaff Cutter,Hand Chaff Cutter
Hunan Furui Mechanical and Electrical Equipment Manufacturing Co., Ltd. , https://www.thresher.nl