Mechanical Analysis Methods of Cantilever Gearbox Housing

doi:10.1007/s12204-021-2316-2

Abstract

Abstract: The mechanical state of cantilever gearbox housing is different from ordinary ones due to the long arm of force caused by cantilever structure. Conventional mechanical analysis methods either took cantilever gearbox housing as ordinary ones or cantilever beam. Few published papers have specially focused on mechanical analysis method for cantilever gearbox housing. This paper takes a longwall shearer cutting unit gearbox (SCUG) as an example and the mechanical analysis method is investigated according to the causes of fatigue for SCUG. Force analysis model is established for finding out regions of static fatigue caused by low-frequency loads, and local resonance analysis is used for finding out regions of vibration fatigue caused by high-frequency loads. Not only bending moment but also torque caused by gear meshing forces is taken into account in the force analysis model. Vibration response is obtained from cutting experiment, and dominant frequencies of local resonance are obtained by frequency domain analysis. Finite element model of SCUG is established, and natural frequencies and strain modes are analyzed for obtaining the main vibration modes corresponding to dominant frequencies. Hence, large stress regions caused by low and high frequency loads are obtained. Results show that the worst working condition is oblique cutting, and the stress of B-B in 600 mm cutting depth can reach 166 MPa. Obviously, 950 Hz, 1 250 Hz, and 1 400 Hz are dominant frequencies of SCUG (23rd, 25th and 27th natural frequencies). Generally, this paper proposes some principles for mechanical analysis method of cantilever gearbox housing.

Key words: cantilever gearbox housing, mechanical analysis method, static fatigue, vibration fatigue, dynamic characteristics, cutting experiment

摘要： 由于箱体结构的差异，长悬臂式齿轮箱的受力状态与普通齿轮箱不同。传统的力学分析方法将悬臂式齿轮箱体视作悬臂梁，或者是普通箱体，相关研究文献很少。本文以采煤机截割部齿轮箱（SCUG）为例，根据SCUG的疲劳原因，研究了其力学分析方法。建立了力分析模型，找出低频载荷引起的静态疲劳区域，并利用局部共振分析找出高频载荷引起的振动疲劳区域。在力分析模型中，不仅考虑了弯曲力矩，还考虑了齿轮啮合力引起的扭矩。通过切削试验获得了振动响应，通过频域分析获得了局部共振的主频。建立了SCUG的有限元模型，并对其固有频率和应变模态进行了分析，得到了与主频相对应的主要振动模态。因此，获得了由低频和高频载荷引起的大应力区域。结果表明，最恶劣的工作条件是斜切截割，在600 mm切削深度下B-B的应力可达166 MPa。很显然，950 Hz、1 250 Hz和1 400 Hz是SCUG的主要频率（第23、25和27个自然频率）。最后，本文提出了悬臂齿轮箱壳体力学分析方法的一些原则。

关键词: 悬臂式齿轮箱；力学分析方法；静态疲劳；振动疲劳；动力学特性；截割试验

CLC Number:

TD 421

WANG Jue∗ (王珏), LI Peng (李朋), SONG Shiyao (宋诗瑶). Mechanical Analysis Methods of Cantilever Gearbox Housing[J]. J Shanghai Jiaotong Univ Sci, 2023, 28(2): 233-242.

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