激光熔覆摆针刮板式同步送粉器的设计

为解决细粉末输送问题,开发一种新型摆针刮板式送粉器,槽型凸轮的转动带动摆针摆动使粉末均匀地落在粉盘上,然后在载气作用下送到熔池。为了验证其性能,分别选用不同粒度、物性的粉末进行了三组送粉及激光熔敷对比试验,获得了理想的效果,并验证了其可以均匀稳定地输送细粉末。

构件运动尺寸的公差对横摆针机构运动轨迹的影响分析

本文运用偏差分组结合的原理及计算机辅助设计技术对GG2-1型曲折缝工业缝纫机中的横摆针机构进行了运动轨迹分析。采用横摆针机构实现Z型缝迹宽度在一定范围内可调是该机的主要特点,同时其装配质量明显地影响整机的产品精度。在不改变现有产品中零件加工精度的前提下,应用优化组合方法得到了组成机构的构件与机壳间的最佳组合,使产品的装配质量有较大的改善,并可为今后的改进设计提供理论指导。文中所采用的方法及计算软件也可应用于其他机构的研究。

摆针法测微型轴承摩擦力矩

介绍了一种用摆针法测量微型轴承摩擦力矩的新方法,分析了系统的测试原理以及计算摩擦力矩的算法。详细介绍了该测试系统的结构以及工作原理,该测量方法利用数字图像处理来解决测量微型轴承摩擦力矩的问题,具有结构简单、精度高等特点。

摆线针轮行星减速机构在木工机床进料系统上的应用

摆线针轮行星减速机构,是一种应用行星传动原理,采用摆线齿啮合,设计先进、结构合理的减速机构,该机构已广泛的应用于起重、运输、矿山、冶金、石油化工、纺织、印染、轻工、制药、食品机械等行业。 今天,我把摆线针轮行星减速机构应用于木工机床进料系统上。实践证明,其效果上优于其它减速机构。

Mesh stiffness calculation of cycloid-pin gear pair with tooth profile modification and eccentricity error

Cycloid speed reducers are widely used in many industrial areas due to the advantages of compact size, high reduction ratio and high stiffness. However, currently, there are not many analytical models for the mesh stiffness calculation, which is a crucial parameter for the high-fidelity gear dynamic model. This is partially due to the difficulty of backlash determination and the complexity of multi-tooth contact deformation during the meshing process. In this paper, a new method to calculate the mesh stiffness is proposed including the effects of tooth profile modification and eccentricity error. The time-varying mesh parameters and load distribution of cycloid-pin gear pair are determined based on the unloaded tooth contact analysis （TCA） and the nonlinear Hertzian contact theory, allowing accurate calculations of the contact stiffness of single tooth pair and the torsional stiffness of multi-tooth pairs. A detailed parametric study is presented to demonstrate the influences of tooth profile modification, applied torque and eccentricity error on the torsional mesh stiffness, loaded transmission error, Hertzian contact stiffness and load sharing factor. This model can be applied to further study the lost motion and dynamic characteristics of cycloid speed reducer and assist the optimization of its precision, vibration and noise levels.

Lubrication characteristics of cycloid pin wheel transmission of RV reducer

In order to analyze the lubricating characteristics at different meshing points in the cycloid pin wheel transmission process,the cycloid gear teeth were discretized,combined with the kinematic analysis of the cycloid pin gear transmission and the contact analysis of the gear teeth.The progressive mesh densification method(PMD)was used to numerically solve the film thickness.The influence of the design parameters and process parameters on the lubrication characteristics was analyzed.The elastohydrodynamic lubrication and mixed lubrication characteristics at different contact points were obtained.The optimal meshing area of the cycloid gear tooth was determined,and the film thickness ratio,contact load ratio,maximum contact pressure at different points,average film thickness and roughness after contact deformation were analyzed.The conclusion of this study provides effective guidance for the research on the modification of cycloid gear teeth.

OBSERVATION ON THE THERAPEUTIC EFFECT OF ACUPUNCTURE TREATMENT OF 123 CASES OF SCAPULOHUMERAL PERIARTHRITIS

Objective: To observe the therapeutic effect of Qinglong Bai Wei Zhen Fa (Green Dragon Shaking Tail Needling) in the treatment of scapulohumeral periarthritis. Methods: A total of 231 cases of scapulohumeral periarthritis patients were randomized into treatment group (n=123) and control group (n=108). In treatment and control groups, Jianyu (LI 15), Jianqian and Jianhou were used as the main acupoints and stimulated with Green Dragon Shaking Tail Needling and conventional needling separately. Additionally, in control group, Waiguan (TE 5) and Binao (LI 14) were supplemented. The treatment was given once daily, with 10 days being a therapeutic course, 2 courses altogether. Results: After the first course of treatment, in treatment and control groups, the cured, the markedly improved, the effective and ineffective cases were 49 and 12, 61 and 33, 11 and 40, 2 and 23, with the total effective rates being 98.4% and 78.7% respectively. There was a marked difference between two groups in the therapeutic effect (P<0.05). Following 2 courses of treatment, the cured, the markedly improved, the effective and ineffective cases were 66 and 21, 47 and 41, 10 and 39, 0 and 7, with the total effective rates being 100% and 93.5% separately. No significant difference between two groups in the total effective rates, but the cure rate of treatment group was strikingly higher than that of control group. Conclusion: Green Dragon Shaking Tail Needling is significantly superior to that of conventional needling in the treatment of scapulohumeral periarthritis.

Three-dimensional atomic force microscopy based on tailored cantilever probe with flared tip

In order to meet the requirements of nondestructive testing of true 3D topography of micro-nano structures,a novel three-dimensional atomic force microscope(3D-AFM)based on flared tip is developed.A high-precision scanning platform is designed to achieve fast servo through moving probe and sample simultaneously,and several combined nanopositioning stages are used to guarantee linearity and orthogonality of displacement.To eliminate the signal deviation caused by AFM-head movement,a traceable optical lever system is designed for cantilever deformation detection.In addition,a method of tailoring the cantilever of commercial probe with flared tip is proposed to reduce the lateral force applied on the tip in measurement.The tailored probe is mounted on the 3D-AFM,and 3D imaging experiments are conducted on different samples by use of adaptive-angle scanning strategy.The results show the roob-mean-square value of the vertical displacement noise(RMS)of the prototype is less than 0.1 nm and the high/width measurement repeatability(peak-to-peak)is less than 2.5 nm.

Modified green dragon swaying its tail needling manipulation for treatment of knee osteoarthritis

Objective To compare the difference in the effect of modified green dragon swaying its tail needling manipulation and common needling manipulations on the overall rating of pain of patients with knee osteoarthritis, and to evaluate the advantages of modified green dragon swaying its tail needling manipulation for. Methods Ninety-five patients with knee osteoarthritis were divided into 2 groups according to the random number table method with 48 patients in the modified green dragon swaying its tail group（group special manipulation, SM group for short） and 47 patients in the common acupuncture group（group convention needling, CN group for short）, and different acupuncture manipulations were applied in the two groups. Internationally recognized Simplified Mc Gill Pain Questionnaire（SF-MPQ） scale used for description and measurement of pain was applied to evaluate the pain degree, including pain rating index（PRI）, visnal analogue scale（VAS）and present pain intensity（PPI）. The index of severity for osteoarthritis（ISOA） was adopted for evaluation of clinical efficacy. Results（1） In SM group, the scores of PRI, VAS and PPI were 6.63±4.67, 2.23±1.45 and 0.65±1.32, respectively, after treatment, and in CN group, the scores of PRI, VAS and PPI were 13.32±7.96, 4.34±1.79 and 2.28±1.21, respectively, the scores decreased in the two groups after treatment（all P〈0.05）, and the improvement in SM group was superior to that in CN group（all P〈0.01）.（2） The clinical cure rate in SM group was 52.08%, and the total effective rate was 97.92%, the clinical cure rate in CN group was 25.53%, and the total effective rate was 85.10%. The comparison of clinical cure rate in the two groups showed that P〈0.01. Conclusion The SM group is obviously superior to CN group in the improvement of overall rating of pain of patients. It is indicated that modified green dragon swaying its tail acupuncture therapy can effectively relieve the pain of patients with knee osteoarthritis, which was worthy of popularization and application with definite clinical efficacy

Effect of modified Qing Long Bai Wei needling on the levels of IL-1β, IL-6 and INF-α in synovial fluid of knee osteoarthritis patients

Objective:To compare the modified Qjng Long Bai Wei needling method and ordinary acupuncture method in the effects of improving the levels of interleukin (IL)-1β,IL-6 and tumor necrosis factor (TNF)-α in the treatment of knee osteoarthritis (KOA),and to determine the advantage of the modified Qing Long Bai Wei needling method for KOA.Methods:One hundred KOA patients were randomized into a treatment group and a control group by using the random number table,with 50 cases in each group.The treatment group was intervened by the modified Qing Long Bai Wei needling method,and the control group was given ordinary acupuncture.The two groups were observed before and after the treatment to determine the changes in the levels of IL-1β,IL-6 and TNF-α in synovial fluid,and the clinical efficacies were compared between the two groups.Results:The total effective rate and clinical recovery rate were 97.9％ and 52.1％ respectively in the treatment group,versus 85.1％ and 25.5％ in the control group,and the between-group differences were statistically significant (both P＜0.01).After the treatment,the levels of Ib1β,IL-6 and TNF-cα in synovial fluid changed significantly in both groups (all P＜0.01);there were significant differences in the levels of IL-1β,IL-6 and TNF-α in synovial fluid between the two groups (all P＜0.01).Conclusion:The modified Qjng Long Bai Wei needling is an effective method for KOA and it can significantly improve the levels of IL-1β,IL-6 and TNF-α in synovial fluid.