Cam Plate Research Articles

The Isolation and Characterization of a Novel Psychrotolerant Cellulolytic Bacterium, Microbacterium sp. QXD-8T.

Cellulolytic microorganisms play a crucial role in agricultural waste disposal. Strain QXD-8T was isolated from soil in northern China. Similarity analyses of the 16S rRNA gene, as well as the 120 conserved genes in the whole-genome sequence, indicate that it represents a novel species within the genus Microbacterium. The Microbacterium sp. QXD-8T was able to grow on the CAM plate with sodium carboxymethyl cellulose as a carbon source at 15 °C, forming a transparent hydrolysis circle after Congo red staining, even though the optimal temperature for the growth and cellulose degradation of strain QXD-8T was 28 °C. In the liquid medium, it effectively degraded cellulose and produced reducing sugars. Functional annotation revealed the presence of encoding genes for the GH5, GH6, and GH10 enzyme families with endoglucanase activity, as well as the GH1, GH3, GH39, and GH116 enzyme families with β-glucosidase activity. Additionally, two proteins in the GH6 family, one in the GH10, and two of nine proteins in the GH3 were predicted to contain a signal peptide and transmembrane region, suggesting their potential for extracellularly degrade cellulose. Based on the physiological features of the type strain QXD-8T, we propose the name Microbacterium psychrotolerans for this novel species. This study expands the diversity of psychrotolerant cellulolytic bacteria and provides a potential microbial resource for straw returning in high-latitude areas at low temperatures.

Numerical and experimental analyses of the performance of a vertical axis turbine with controllable-blades for ocean current energy

Phasing out high-carbon-emission fossil fuels and using renewable energy have become a global consensus for mitigating climate change. For the application of renewable energy, this study proposes a high-efficiency controllable-blade vertical axis turbine, which has six blades and a cam plate, for ocean current power generation. A novel design for the turbine using cam to control the opening and closing of blades to enhance the performance of vertical axis turbines. The design feature of the drag-type blade is to be active or open quickly in downstream. The effective area of the blade under thrust is increased to enhance the performance. On the other hand, the blade is designed to be inactive or close quickly in upstream and the drag of blade in upstream can be reduced. A commercial software, ANSYS FLUENT is used to simulate the performance of the vertical turbine. The streamline, velocity, and pressure around the turbines are then obtained. The power coefficients and torques are evaluated at various angular velocities and tip speed ratios and are validated by experimental results. The maximum power coefficient of the proposed turbine occurs at an angular velocity ratio of 4 with quick opening of blades and is higher than that of 3, 5, or 6 by 3.4 %, 2.7 %, or 7.4 %, respectively. In addition, performance comparisons among controllable-blade vertical axis turbine, fixed-blade vertical axis turbine, and Savonius turbine are made. The results show that the maximum power coefficient of the presented controllable-blade vertical axis turbine is 143 % and 103 % higher than that of the fixed-blade vertical axis turbine and Savonius turbine at V = 1 m/s, respectively.

Enhanced in vitro model of the CSF dynamics

BackgroundFluid dynamics of the craniospinal system are complex and still not completely understood. In vivo flow and pressure measurements of the cerebrospinal fluid (CSF) are limited. Whereas in silico modeling can be an adequate pathway for parameter studies, in vitro modeling of the craniospinal system is essential for testing and evaluation of therapeutic measures associated with innovative implants relating to, for example, normal pressure hydrocephalus and other fluid disorders. Previously-reported in vitro models focused on the investigation of only one hypothesis of the fluid dynamics rather than developing a modular set-up to allow changes in focus of the investigation. The aim of this study is to present an enhanced and validated in vitro model of the CSF system which enables the future embedding of implants, the validation of in silico models or phase-contrast magnetic resonance imaging (PC-MRI) measurements and a variety of sensitivity analyses regarding pathological behavior, such as reduced CSF compliances, higher resistances or altered blood dynamics.MethodsThe in vitro model consists of a ventricular system which is connected via the aqueduct to the cranial and spinal subarachnoid spaces. Two compliance chambers are integrated to cushion the arteriovenous blood flow generated by a cam plate unit enabling the modeling of patient specific flow dynamics. The CSF dynamics are monitored using three cranial pressure sensors and a spinal ultrasound flow meter. Measurements of the in vitro spinal flow were compared to cervical flow data recorded with PC-MRI from nine healthy young volunteers, and pressure measurements were compared to the literature values reported for intracranial pressure (ICP) to validate the newly developed in vitro model.ResultsThe maximum spinal CSF flow recorded in the in vitro simulation was 133.60 ml/min in the caudal direction and 68.01 ml/min in the cranial direction, whereas the PC-MRI flow data of the subjects showed 122.82 ml/min in the caudal and 77.86 ml/min in the cranial direction. In addition, the mean ICP (in vitro) was 12.68 mmHg and the pressure wave amplitude, 4.86 mmHg, which is in the physiological range.ConclusionsThe in vitro pressure values were in the physiological range. The amplitudes of the flow results were in good agreement with PC-MRI data of young and healthy volunteers. However, the maximum cranial flow in the in vitro model occurred earlier than in the PC-MRI data, which might be due to a lack of an in vitro dynamic compliance. Implementing dynamic compliances and related sensitivity analyses are major aspects of our ongoing research.

Experimental investigation of a free piston expander-linear generator with different valve timings

In this paper, a new free piston expander-linear generator (FPE-LG) prototype for small-scale organic Rankine cycle (ORC) waste heat recovery system has been developed. Firstly, the in-cylinder pressure, motion characteristics and output performance of the FPE-LG with different valve timings are investigated. Then, the effect of external load resistance on motion characteristics and output performance with cam plate A is analyzed. Finally, the effect of external load resistance on the indicated efficiency with cam plate A is studied. The results show that the intake duration and exhaust duration have significant influence on the motion characteristics and output performance of FPE-LG. Compared with other cam plates, cam plate A (the intake exhaust duration is 60°, and the exhaust duration is 180°) can be considered as the best choice for FPE-LG. The external load resistance not only influences the motion characteristics but also effects the output performance. The displacement and velocity increase with increasing the external load resistance. The peak power output with cam plate A is up to 18.6 W. The indicated efficiency shows a downward tendency when the external load resistance increases, and the maximum indicated efficiency of 66.2% is achieved.

Hydrodynamic processes in the piston and cylinder unit of axial-piston hydraulic machines

The purpose of the research was to analyze the kinematics of the piston mechanism of an axial-piston hydraulic machine with an adjustable-angle cam plate. The kinematic analysis resulted in establishing various types of relative motion of the piston in the guide bushing, writing and solving Reynolds equation with respect to velocities. A sweep method was used to construct a pressure field in the working fluid layer between the piston and the guide bushing. Pressure fields are constructed for several cases of kinematics of the piston mechanism.

Backlash Evaluation of Hybrid UHMWPE-PEEK Bushes in a Small Robot Joint System

In our previous work, we designed a new joint system for humanoid sized robot. This system consists of a servomotor, a harmonic drive and a link unit. This link unit includes three components; polymer bushes, a metal cam plate and a metal camshaft. However elastic deformation of all-polymer bushes can cause a large backlash in the system. In the present work, a new bush was developed and its fatigue behavior was investigated.

Preliminary Development of a Free Piston Expander–Linear Generator for Small-Scale Organic Rankine Cycle (ORC) Waste Heat Recovery System

A novel free piston expander-linear generator (FPE-LG) integrated unit was proposed to recover waste heat efficiently from vehicle engine. This integrated unit can be used in a small-scale Organic Rankine Cycle (ORC) system and can directly convert the thermodynamic energy of working fluid into electric energy. The conceptual design of the free piston expander (FPE) was introduced and discussed. A cam plate and the corresponding valve train were used to control the inlet and outlet valve timing of the FPE. The working principle of the FPE-LG was proven to be feasible using an air test rig. The indicated efficiency of the FPE was obtained from the p–V indicator diagram. The dynamic characteristics of the in-cylinder flow field during the intake and exhaust processes of the FPE were analyzed based on Fluent software and 3D numerical simulation models using a computation fluid dynamics method. Results show that the indicated efficiency of the FPE can reach 66.2% and the maximal electric power output of the FPE-LG can reach 22.7 W when the working frequency is 3 Hz and intake pressure is 0.2 MPa. Two large-scale vortices are formed during the intake process because of the non-uniform distribution of velocity and pressure. The vortex flow will convert pressure energy and kinetic energy into thermodynamic energy for the working fluid, which weakens the power capacity of the working fluid.

Dual Side Water Pumping System using Scotch Yoke Mechanism

The aim of the paper is to design and develop a dual side water pumping system using scotch yoke mechanism. The reciprocating motion of the plunger is utilized for the pumping action. The plunger is reciprocated with the help of a cam plate. By this action the water is pumped with very high pressure and to various heads. This can be utilized for various applications like lubrication in machines and water pumping in agriculture field. The cam plate gets the drive from the motor for its rotation and converts that rotary motion to useful dual side reciprocating motion. The motor is powered with the aid of electric power. Thus the water is pumped from source to various heads.

Stress Analysis for Globoidal Indexing Cam Mechanism with Steel Ball

This paper presents stress analysis for globoidal indexing cam mechanism with steel ball, and stress model of each component is established. Globoidal indexing cam mechanism with steel ball is made up of globoidal cam, indexing plate and steel ball. The mechanism can realize approximate rolling transmission. Stress is analyzed for globoidal cam, indexing plate and steel ball at dell and indexing period respectively. According to rotary transform tensor theory stress in different coordinate system is obtained to build static equilibrium equations for steel ball conveniently. Axial force, radial force and peripheral force for globoidal cam and indexing plate are reached.

Measurement of fatigue and wear of PEEK bush and A7075 cam plate in humanoid robot joints

Machine elements in humanoid robots for our life support require light weight, high accuracy and high output torque. In order to achieve low transmission error of the humanoid robot joints, wear of reinforced poly-ether-ether-ketone (PEEK) bushes against the 7075 aluminium alloy cam plates is investigated. Sliding fatigue wear tests of PEEK bushes in the humanoid robot leg joint were performed under various load torques. In the case of the bush under 127 Nm load torque at 5·7 mm s−1 sliding velosity, the backlash values were stable after the running process in fatigue wear test. PEEK film was formed by the friction between PEEK bush and 7075 cam plate under compression load. The oscillation angle of the output axis in the robot joint was stable after early stage because of the solid lublication caused by the film. This means the backlash value was stable and decreased due to the PEEK film between the bush and the cam plate.

Measurement of Backlash and Fatigue Wear of PEEK Bush in Robot Joint under Middle Load

In order to establish the application possibilities in transmission parts in humanoid robot joints, wear of reinforced poly-ether-ether-ketone (PEEK) polymer bushes in friction against 7075 aluminium alloy cam plates is investigated. Additionally the transmission error (backlash) in robot joint was measured. The PEEK bush wear requires close examination as well as the input axis-output axis transmission error. Fatigue wear tests were performed on bushes under middle load at 3000 rpm motor speeds, while the cam plate oscillated in the humanoid robot leg joint evaluation system under 1300 kgfcm (132 Nm) load torque. The robot joint using PEEK bush achieved stable small backlash due to good friction perforance.

Change in Backlash of Humanoid Robot Joints under High Load

In this work, wear of reinforced poly-ether-ether-ketone (PEEK) polymer bushes in friction against 7075 aluminium alloy cam plates or titanium crankshafts is investigated in order to establish the application possibilities in transmission parts in humanoid robot joints under high load torque. The PEEK bush wear requires close examination as well as the input axis-output axis transmission error (backlash). Sliding wear tests were performed on bushes under 4000 kgfcm (392 Nm) load torque, while the cam plate oscillated in the humanoid robot leg joint evaluation system. The robot joint using PEEK bush achieved quite small backlash after the fatigue wear test.

Kinematics Simulation and Experimental Study of CVT with Diclinic Cam Plate Synchronous Revolution and Internal Power Shunt

Established the precise model and completed the virtual assembly of CVT with diclinic cam plate synchronous revolution and internal power shunt application of Pro/E software basing on the transmission principle. Obtained the displacement, velocity and acceleration time-dependent curves of nine plungers centroid through the simulation of transmission operation, based on the simulation analysis gaining that the transmission does not exist in dynamic and static interference, and the structure design of CVT is reasonable. Completed the processing of CVT manufacturing, experiments are carried out to verify the simulation analysis of the transmission of real.

Dynamic Simulation and Design Improvement of CVT with Diclinic Cam Plate Synchronous Revolution and Internal Power Shunt

According to the dynamic unbalance problem of CVT with diclinic cam plate synchronous revolution and internal power shunt, using structural optimization method to make high-speed rotation counterweight balance after the bearing stress distribution to achieve the best. Put forward the improvement scheme through the analysis of dynamic simulation and theory analysis. The results show that, the improved plunger structure can reduce fluctuation amplitude of bearing support reverse force when the transmission in high speed.

Wear and Transmission Error between PEEK Bush and 7075 Aluminium Alloy Cam Plate Components in Robot Joints

In this work, wear of reinforced poly-ether-ether-ketone (PEEK containing PTFE, graphite and carbon fibres) polymer bushes in friction against 7075 aluminium alloy cam plates is investigated in order to establish the application possibilities in transmission parts in humanoid robot joints. The PEEK bush surface conditions as well as the input axis-output axis transmission error (backlash) require close examination. Sliding wear tests were performed on bushes under 900 kgfcm loaded torque, while the cam plate oscillated. Based on the wear observation, it was found that PEEK wear fragments in the interface between PEEK bush and aluminium alloy cam plate formed a PEEK film.

Influence of Wear and Backlash on Machined PEEK Polymer Bushes and 7075 Aluminium Alloy Cam Plates Used in Robot Joints

Due to constant exposure to high torque and loads toughness, compressive durability and light weight of joint parts are crucial factors for biped walking humanoid robot parts. When polymer transmission parts are used for the manufacture of humanoid robot joint, wear becomes an important factor in terms of transmission error (backlash) between the input and output axes, ex. between the motor and the robot’s leg joint. In such joint system, a polymer bushes is directly connected to a cam plate, playing an important role in the robot's movement ability. In this work, the influence of wear of reinforced poly-ether-ether-ketone (PEEK) polymer bushes in friction against 7075 aluminium alloy cam plates is investigated in order to establish the application possibilities in transmission parts in humanoid robot’s joint. The PEEK bush surface conditions as well as the input axis-output axis backlash require close examination, so that efficient systems can be built. Sliding wear tests were performed on bushes under 0-50kgfcm loaded torque while the cam plate oscillated. Based on the wear observation, it was found that in a high load range the backlash increased along with number of cycles due to PEEK bush wear. The bush surface roughness also increased during testing. Roughness of PEEK bush surface and the loaded torque for output axis were significantly related to backlash of output axis in robot joint.

Implementation of a 3 times zoom lens barrel system for a 5M camera module using a mobile phone

In this study, we developed a small 3 times zoom lens barrel for a 5M camera module to load a mobile phone set. Its dimensions are 16mm × 9mm × 28mm and is constructed with 8 sheets of lenses, two step motors, some gears, a cam plate and so on.

Theoretical and experimental studies on the steady-state performance of low-speed high-torque hydrostatic drives. Part 1: Modelling

In this article the steady-state models of an open-circuit and a closed-circuit hydrostatic transmission (HST) drive have been developed to study their performances. A low-speed high-torque multi-stroke cam plate type radial piston motor is considered for both HST drives. Bondgraph simulation technique has been used to model the drives. The multi-bondgraph representation of the HST drives is presented; it takes into account the compression and expansion phases, which occur sequentially in the hydraulic motor. A reduced bondgraph model of the drives has been proposed, where various losses are lumped into suitable resistive elements. The relationships of the loss coefficients with other state variables, obtained from the reduced model, are identified through experimental investigation. The loss coefficients are found to have a non-linear relationship with the load torque and the supply flowrate. Using the characteristics of these loss coefficients, the steady-state performances of the hydrostatic drives are studied in Part 2 of this article (pg. 2675 of this issue).

Possibilities of diagnosing cavitation in hydraulic systems

Conditions of arising cavitation and experimental investigations of this phenomenon by means of a special vacuum vessel are described. A simulation model of the piston–cylinder unit of a pump with an inclinable cylinder block was used to visualize cavitation in the pump. The results of tests aimed at showing a correlation between the onset of cavitation and an audible diagnostic signal are presented. The suction space of the tested axial-flow multipiston positive-displacement pump with an inclinable cam plate was selected as the most likely place for cavitation to occur. An audible diagnostic signal indicating the onset of cavitation was also detected in the case of a multipiston pump with an inclinable cylinder block. An example of the configuration of an acoustic probe kit for use under industrial conditions is presented.

A PARAMETRIC STUDY OF PLANAR CAM-ROLLER SPEED REDUCERS

Speed-o-Cam, a family of speed-reduction mechanisms based on cams and pure-rolling contact, is currently under development at McGill University’s Centre for Intelligent Machines. It is intended to replace gears and harmonic drives in applications where backlash, friction, and flexibility cannot be tolerated. We focus on the pressure angle and the machinability of internal and external planar Speedo-Cam layouts. In particular, this paper regards the pressure angle and the machinability as design constraints, while focusing on the Speed-o-Cam parameter optimization. A total of three design parameters, is investigated, so as to find the relationships between these parameters and the pressure angle, and the machinability of the cam plate. Optimum parameter values are thus obtained.