Electrostatically Actuated Surface Micromachined Offset Planetary Gear Pump Design

2001 ◽  
Author(s):  
Mohammad I. Kilani ◽  
Paul C. Galambos ◽  
Yousef S. Haik ◽  
Ching-Jen Chen
Keyword(s):  
Roller Bearing ◽  
Planetary Gear ◽  
Gear Train ◽  
Gear Pump ◽  
Ring Gear ◽  
Surface Micromachining ◽  
Eccentric Rotation ◽  
Pump Design ◽  
Electrostatically Actuated ◽  
Mechanical Elements

Abstract An offset planetary pump fabricated in five-level polysilicon surface micromachining is introduced. The pump consists of a ring gear enclosing two planetary gears and an offset sun gear, which generates pumping due to its eccentric rotation. The pump is driven by an electrostatically actuated comb-drive microengine and mechanical power is transmitted to the ring gear through a micro gear train. The paper presents a derivation of pump capacity and the detailed design of its mechanical elements, demonstrating the implementation of relatively advanced mechanical functions in multi-level surface micromachining, including axial roller bearing support, fluidic seal and planetary gear transmission.

A PLANETARY GEAR TRAIN WITH RING-INVOLUTE TOOTH

2008 ◽  
Vol 32 (2) ◽  
pp. 251-266
Author(s):  
Shyue-Cheng Yang ◽  
Tsang-Lang Liang
Keyword(s):  
Planetary Gear ◽  
Conjugate Problem ◽  
Gear Ratio ◽  
Gear Train ◽  
Tooth Surface ◽  
The Sun ◽  
Ring Gear ◽  
Planetary Gear Train ◽  
Envelope Method ◽  
Planet Gear

This paper proposes a planetary gear train with ring-involute tooth profile. Inherent in a planetary gear train is the conjugate problem among the sun, the planet gears and the ring gear. The sun gear and the planet gear can be obtained by applying the envelope method to a one-parameter family of a conical tooth surface. The conical tooth rack cutter was presented in a previous paper [5]. The obtained planet gear then becomes the generating surface. The double envelope method can be used to obtain the envelope to the family of generating surfaces. Subsequently the profile of a ring gear of the planetary gear trains can be easily obtained, and using the generated planet gear and applying the gear theory, the ring gear is generated. To illustrate, the planetary gear train with a gear ratio of 24:10:7 is presented. Using rapid prototyping and manufacturing technology, a sun gear, four planet gears, and a ring gear are designed. The RP primitives provide an actual full-size physical model that can be analyzed and used for further development. Results from these mathematical models are applicable to the design of a planetary gear train.

Random vibration analysis of thin-walled elastic rings under multiple moving loads

2021 ◽  
pp. 095440622199640
Author(s):  
Jalal Taheri Kahnamouei ◽  
Jianming Yang
Keyword(s):  
Random Vibration ◽  
Planetary Gear ◽  
Gear Train ◽  
Design Parameters ◽  
Ring Gear ◽  
Moving Loads ◽  
Newmark Scheme ◽  
Mean And Variance ◽  
Thin Walled ◽  
Bolt Connection

This paper investigates the random vibration of a thin-walled ring subjected to multiple moving loads from the inside of the ring. A ring gear in a planetary gear train with three equally-spaced planets is taken as an example. The ring is discretized with the finite element method of curved beam elements. The supports of the ring gear are treated as three linear springs to mimic a general bolt connection. The stochastic Newmark algorithm is used to solve the equations and obtain the response's mean and variance. Monte Carlo simulations are also conducted to verify the results from the stochastic Newmark scheme. A parametric study is conducted to examine the effect of design parameters on the responses.

Dynamic Analysis of Hybrid Gear Trains With Flexible Ring Gear Rim

2017 ◽  
Author(s):  
Xiangyang Xu ◽  
Junbin Lai ◽  
Yanfang Liu
Keyword(s):  
Dynamic Behavior ◽  
Planetary Gear ◽  
Transmission Error ◽  
Helical Gear ◽  
Gear Train ◽  
Gear Pair ◽  
Ring Gear ◽  
Gear Trains ◽  
Helical Gear Pair ◽  
Flexible Ring

In this paper, the dynamic behavior of a hybrid gear train (HGT), consists of a single-stage helical planetary gear set and a helical gear pair, is analyzed. A ring gear rim is connected with an internal gear in a helical planetary gear set and an external gear in a helical gear pair. Power flows from the helical gear pair to the helical planetary gear set. Therefore, loads in the external gear would cause additional axial force and radial force, which would lead to unexpected moment and force. As a result, deflections of ring gear rim must be taken into consideration. Under this condition, a three-dimensional dynamic model of a HGT with flexible ring gear rim is developed, in which six degrees of freedom including three translational motions and three rotational motions are employed. Coupling effects of the bearing support stiffness, gear mesh stiffness and time-varying transmission error are taken into consideration. The model also takes flexible supporting shafts and planet carrier into consideration by using finite element method. Then, the equations of motion in matrix form are established and solved to predict the forced vibration response due to the transmission error excitations. Subsequently, effects of positions of the helical gear pair relative to the planetary gear set and the thickness of ring gear rim on dynamic behavior of the HGT are discussed. The results show that the proposed model is potential and can be used to guide the design of hybrid gear trains.

A multi-body dynamic study of vibration of a planetary gear train with the planetary bearing fault

2019 ◽  
Vol 233 (3) ◽  
pp. 677-695 ◽  
Author(s):  
Jing Liu ◽  
Linfeng Wang ◽  
Jinlei Ma ◽  
Wennian Yu ◽  
Yimin Shao
Keyword(s):  
Dynamic Model ◽  
Dynamic Modelling ◽  
Planetary Gear ◽  
Elastic Support ◽  
Gear Train ◽  
Radial Clearance ◽  
Ring Gear ◽  
Planetary Gear Train ◽  
Multi Body ◽  
Body Dynamic

Local faults including pits and spalls in any planet bearing can greatly affect the vibration of the planetary gear train, as well as the elastic support of the ring gear. However, the dynamic modelling methods in previous work can only formulate the local fault and the elastic support of the ring gear independently. To address this issue, a multi-body dynamic model for a planetary gear train with a local fault in the planet bearing and an elastic ring gear foundation are introduced to analyze the effect of local fault on the vibration. The local fault in the planet bearing is modelled as a rectangular one. Both the planet bearings including the radial clearance and ring gear with an elastic foundation are considered in the multi-body dynamic model. The contact stiffnesses and damping coefficients of gears and bearings are calculated by the methods reported in the literature. A Coulomb friction model is adopted to model the frictions between mating components of the system. In order to validate the proposed multi-body dynamic model, its simulation results are directly compared with those from theoretical methods as well as the experimental methods reported in the literature. Moreover, parameter studies are conducted to discuss the effects of local faults in the planet-bearing races, the sun gear speed, and the carrier moment on the vibration of the planetary gear train. The analyzing results of this study can provide some guidance for detection approaches of local faults in the planet bearings of planetary gear trains through vibration analysis.

Coupling effects of manufacturing error and flexible ring gear rim on dynamic features of planetary gear

2021 ◽  
pp. 095440622098336
Author(s):  
Zheng Cao ◽  
Meng Rao
Keyword(s):  
Planetary Gear ◽  
Gear Train ◽  
Influence Coefficient ◽  
Ring Gear ◽  
Dynamic Features ◽  
Coupling Effects ◽  
Manufacturing Error ◽  
Manufacturing Errors ◽  
Potential Energy Method ◽  
Flexible Ring

Manufacturing errors widely exist in and deteriorate the dynamic property of planetary gear train (PGT). To solve this problem, the ring gear is often designed with a thin rim to compensate for the effects of manufacturing errors via the elastic deflections of the rim. Existing dynamic models of the PGT only consider the effects of either the elasticity of the rim of the ring gear or the manufacturing errors. The coupling effects of manufacturing errors and the flexible ring gear are ignored. To understand the dynamic behaviors of the PGT better, a dynamic model of the PGT coupled with typical manufacturing error and flexible ring gear is developed in this study. The tooth contact analysis of the ring-planet mesh, which is calculated based on the potential energy method and uniformly curved Timoshenko beam theory, is studied using the influence coefficient method. A numerical algorithm is proposed to solve the integrated dynamic equations of the PGT. Calculated results show that the dynamic features of the PGT are complex, and the load sharing characteristic is improved when the flexible ring gear is incorporated.

Dynamic Response of Planetary Trains to Mesh Parametric Excitations

1996 ◽  
Vol 118 (1) ◽  
pp. 7-14 ◽  
Author(s):  
P. Velex ◽  
L. Flamand
Keyword(s):  
Ritz Method ◽  
Three Dimensional ◽  
Planetary Gear ◽  
Spur Gear ◽  
Gear Train ◽  
Ring Gear ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Critical Speeds ◽  
The Difference

An extended three-dimensional model is used for calculating dynamic tooth loads on a planetary gear set. Time dependent mesh stiffnesses are determined and an original Ritz method aimed at solving large parametrically excited differential systems is proposed. Results from the Ritz method compare favorably with those given by direct integrations for highly reduced computation times. The difference between local critical speeds (for one individual mesh) and global critical speeds (for sun or ring gear-planet meshes) on a sequential spur gear train is pointed out. Finally, it is shown that, for linear behaviors, mesh stiffnesses are largely controlling dynamic tooth loads while the influence of a floating sun or ring gear is less important.

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