Evaluation of Power Loss of the Rubber V-Belt CVT

1998 ◽  
Author(s):  
T. F. Chen ◽  
C. K. Sung
Keyword(s):  
Power Loss ◽  
Wedge Angle ◽  
Operating Conditions ◽  
Total Power ◽  
Speed Ratio ◽  
Rotating Speed ◽  
Continuously Variable Transmissions ◽  
Torque Loss ◽  
Motion Characteristics ◽  
Loss Mechanisms

Abstract This paper proposes a systematic method for the evaluation of power loss of rubber V-belt continuously variable transmissions (CVT). By observing the interaction between belt and sheaves, the entire belt may be divided into four regions. They are free span, wedging-in, adhesion, and wedging-out regions. Therefore, each region possesses a distinct motion characteristic. Herein, power loss is categorized into speed and torque losses. Since speed loss contributes less than 4% of the total power loss in most operating conditions, only torque loss is considered. The mechanisms causing torque loss may be attributed to the hysteresis of belt bending, compression and shear, and friction due to radial motion of the belt. These loss mechanisms are studied on the basis of motion characteristics in each region. Parameters for loss mechanisms are then analyzed to identify their contributions to the system efficiency. These parameters include external load, rotating speed and wedge angle of the pulley, speed ratio, pre-tension, and thickness and tooth profile of the belt. In addition, an experimental study is performed for verification of the proposed analytical approach.

A Communication-Free Decentralized Power Control Approach for Power Loss Minimization in Islanded Microgrids Using Extremum Seeking

2017 ◽  
Author(s):  
Su-Yang Shieh ◽  
Tulga Ersal ◽  
Huei Peng
Keyword(s):  
Power Control ◽  
Power Loss ◽  
Operating Conditions ◽  
Extremum Seeking ◽  
Total Power ◽  
Loss Minimization ◽  
Plug And Play ◽  
Control Approach ◽  
Structure Information ◽  
Power Loss Minimization

This paper considers islanded microgrids and is motivated by the need for decentralized control strategies with minimal communication among grid components to support a robust and plug-and-play operation. We focus on the problem of power allocation among the distributed generation units (DGs) to maintain low distribution power loss in the grid and develop a communication-free distributed power control approach for power loss minimization based on the extremum-seeking (ES) method. In this approach, the DGs implement ES simultaneously and separately to minimize their current outputs by controlling the active power. The total power loss is thus reduced and no grid structure information or communication is needed in the optimization process. The existence of a Nash equilibrium in the resulting non-cooperative game is proved. Numerical simulations are conducted to demonstrate the performance of the proposed communication-free power control approach and show that it is suitable for maintaining low power loss under different operating conditions in a plug-and-play manner.

Development and Performance Measurement of Oil-Free Turbocharger Supported on Gas Foil Bearings

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Yong-Bok Lee ◽  
Dong-Jin Park ◽  
Tae Ho Kim ◽  
Kyuho Sim
Keyword(s):  
Power Loss ◽  
Time Delays ◽  
Operating Conditions ◽  
Total Power ◽  
Stable Operation ◽  
Compressor Wheel ◽  
Foil Bearings ◽  
Vehicle Engine ◽  
Turbine Inlet ◽  
Diesel Vehicle

This paper present the development of an oil-free turbocharger (TC) supported on gas foil bearings (GFBs) and its performance evaluation in a test rig driven by a diesel vehicle engine (EG). The rotor-bearing system was designed via a rotordynamic analysis with dynamic force coefficients derived from the analysis of the GFBs. The developed oil-free TC was designed using a hollow rotor with a radial turbine at one end and a compressor wheel at the other end, a center housing with journal and thrust GFBs, and turbine and compressor casings. Preliminary tests driven by pressurized shop air at room temperature demonstrated relatively stable operation up to a TC speed of 90,000 rpm, accompanied by a dominant synchronous motion of ∼20 μm and small subsynchronous motions of less than 2 μm at the higher end of the speed range. Under realistic operating conditions with a diesel vehicle engine at a maximum TC speed of 136,000 rpm and a maximum EG speed of 3140 rpm, EG and TC speeds and gas flow properties were measured. The measured time responses of the TC speed and the turbine inlet pressure demonstrated time delays of ∼3.9 and ∼1.3 s from that of the EG speed during consecutive stepwise EG speed changes, implying the GFB friction and rotor inertia led to time delays of ∼2.6 s. The measured pressures and temperatures showed trends following second-order polynomials against EG speed. Regarding TC efficiency, 4.3 kW of mechanical power was supplied by the turbine and 3.3 kW was consumed by the compressor at the top speed of 136,000 rpm, and the power loss reached 22% of the turbine power. Furthermore, the estimated GFB power losses from the GFB analysis were approximately 25% of the total power loss at higher speeds, indicating the remainder of the power loss resulted from heat transfer from the exhaust gas to the surrounding solid structures. Incidentally, as the TC speed was increased from 45,000 to 136,000 rpm, the estimated turbine inlet power increased from 19 to 79 kW, the compressor exit power increased from 7 to 26 kW, and the TC output mass flow rate from the compressor increased from 21 to 74 g/s. The average TC compressor exit power was estimated at ∼34% of the turbine inlet power over this range.

Research on Fluid Flow Stability With Baffles of Different Size in a Hydrodynamic Coupling During Partially Liquid-Filled Operating Conditions

2017 ◽  
Author(s):  
Qingdong Yan ◽  
Yuanyuan An ◽  
Wei Wei
Keyword(s):  
Two Phase Flow ◽  
Flow Stability ◽  
Operating Conditions ◽  
Speed Ratio ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Area ◽  
Rotating Speed ◽  
Light Load ◽  
Hydrodynamic Coupling

The hydrodynamic coupling is a power transmission device dependent on the liquid medium momentum change with the advantage of slow shock, isolation of torsional vibration, start light load and overload protection, which is applied in engineering, mining, construction, lifting the transport machinery, et al[1]. The hydrodynamic coupling without inner ring usually works in partially liquid-filled operating conditions, when the flow state changes suddenly with the rotating speed ratio changing. This may lead to unstable gas-liquid two-phase flow in a hydrodynamic coupling in a certain ratio range. To improve the stability of two-phase flow, a baffle is set inside the circulatory circle of a hydrodynamic coupling. The baffle blocks part of the flow area between two wheels in the hydrodynamic coupling. The size of baffle plays an important role on the effect for improving the flow stability. To investigate the influence of the baffle to the internal flow stability, the two-phase flow (liquid-filling rate is 80%) in hydrodynamic couplings with baffles in different sizes and without baffles were studied by Computational Fluid Dynamics (CFD) numerical simulation with the rotating speed of pump at constant 2200 r/min and rotating speed of turbine changing from 0 to 2200r/min. The corresponding distributions of streamlines and characteristics curves were obtained. Through the analysis of turbine torque and efficiency, it is verified that the baffle could improve the flow stability, and the different distributions of streamline could explain the reason. In addition, optimal range of baffle size c = 30% ∼ 40% is obtained by analyzing the simulation results. This will provide a basis for the improvement of design in the hydrodynamic coupling.

Operating characteristics of the variable frequency speed-regulating system for a single pump in a closed system

2016 ◽  
Vol 38 (3) ◽  
pp. 309-317 ◽  
Author(s):  
Yiping Song ◽  
Jianing Zhao
Keyword(s):  
Closed System ◽  
Full Range ◽  
Operating Conditions ◽  
Total Power ◽  
Speed Ratio ◽  
Variable Frequency ◽  
Power Ratio ◽  
Water Pump ◽  
Operating Characteristics ◽  
Pump System

This study experimentally investigated the operating characteristics of the variable frequency speed-regulating system of a water pump in a closed system. The test data for the variable frequency water pump under various conditions were obtained by changing the water pump frequency and the opening setting of a regulator valve in the system. This study revealed that the total power ratio of the water pump system before and after the frequency adjustment did not exhibit cubic correlations with its rotational speed ratio as defined by the affinity law, especially in areas other than the high-efficiency area of pump operation. The equations that express the correlations between the frequency ratio and the total power ratio under the full range of operating conditions were obtained in this study by using the data fitting method. The test confirmed that the fitted characteristic equations had a higher precision and a wider scope of applicability than the existing equations when the water pump, motor, and variable frequency drive were considered as a whole. Practical application: The variable frequency speed-regulating system of a water pump was used in cooling, cooled and heating systems. However, the water pump power was calculated by the standard cube law, and its energy-saving potential was exaggerated. This study revealed a new energy model of a water pump system that can more accurately calculate the total power of the variable frequency water pump in practical engineering.

Power Transmission Losses in V-Belt Drives Part 1: Mismatched Belt and Pulley Groove Wedge Angle Effects

1987 ◽  
Vol 201 (1) ◽  
pp. 33-40 ◽  
Author(s):  
T H C Childs ◽  
D Cowbum
Keyword(s):  
Power Loss ◽  
Power Transmission ◽  
Wedge Angle ◽  
Theoretical Models ◽  
Transmission Losses ◽  
Belt Drives ◽  
Torque Loss

AV 10 raw-edged V-belts cut to wedge angles from 32° to 42° have been run in 36° grooves on pulleys of 51 mm pitch circle radius. It has been shown experimentally that belts with wedge angles from 37° to 38.5° fitted the grooves best and were the most efficient. The excess speed and torque loss parts of the power loss of other belts was due to the larger radial compliance of these belts which did not fit their pulley groove. Current theoretical models of radial compliance of misfitting belts are shown to be wrong. The results have been generalized and a theory of belt bending distortion developed to give detailed recommendations of the most efficient pulley groove angles in which to run belts cut to 40°, depending on pulley radius, belt construction and belt length.

A pilot web former designed to study retention-formation relationships

2010 ◽  
Vol 25 (2) ◽  
pp. 185-194
Author(s):  
Anna Svedberg ◽  
Tom Lindström
Keyword(s):  
Pilot Scale ◽  
Operating Conditions ◽  
Montmorillonite Clay ◽  
Speed Ratio ◽  
Good Reproducibility ◽  
Total Solids ◽  
Retention Aids ◽  
Solids Content ◽  
Relationship Of ◽  
The Relationship

Abstract A pilot-scale fourdrinier former has been developed for the purpose of investigating the relationship between retention and paper formation (features, retention aids, dosage points, etc.). The main objective of this publication was to present the R-F (Retention and formation)-machine and demonstrate some of its fields of applications. For a fine paper stock (90% hardwood and 10% softwood) with addition of 25% filler (based on total solids content), the relationship between retention and formation was investigated for a microparticulate retention aid (cationic polyacrylamide together with anionic montmorillonite clay). The retention-formation relationship of the retention aid system was investigated after choosing standardized machine operating conditions (e.g. the jet-to-wire speed ratio). As expected, the formation was impaired when the retention was increased. Since good reproducibility was attained, the R-F (Retention and formation)-machine was found to be a useful tool for studying the relationship between retention and paper formation.

Optimization for speed regulation strategy of compound coupled hydro-mechanical transmission

2020 ◽  
pp. 095440702098056
Author(s):  
Jin Yu ◽  
Pengfei Shen ◽  
Zhao Wang ◽  
Yurun Song ◽  
Xiaohan Dong
Keyword(s):  
Fuel Consumption ◽  
Dynamic Programming Algorithm ◽  
Operating Conditions ◽  
Programming Algorithm ◽  
Speed Ratio ◽  
Mechanical Transmission ◽  
Speed Regulation ◽  
Ratio Change ◽  
Low Efficiency ◽  
Wheel Loaders

Heavy duty vehicles, especially special vehicles, including wheel loaders and sprinklers, generally work with drastic changes in load. With the usage of a conventional hydraulic mechanical transmission, they face with these problems such as low efficiency, high fuel consumption and so forth. Some scholars focus on the research to solve these issues. However, few of them take into optimal strategies the fluctuation of speed ratio change, which can also cause a lot of problems. In this study, a novel speed regulation is proposed which cannot only solve problems above but also overcome impact caused by speed ratio change. Initially, based on the former research of the Compound Coupled Hydro-mechanical Transmission (CCHMT), the basic characteristics of CCHMT are analyzed. Besides, to solve these problems, dynamic programming algorithm is utilized to formulate basic speed regulation strategy under specific operating condition. In order to reduce the problem caused by speed ratio change, a new optimization is applied. The results indicate that the proposed DP optimal speed regulation strategy has better performance on reducing fuel consumption by up to 1.16% and 6.66% in driving cycle JN1015 and in ECE R15 working condition individually, as well as smoothing the fluctuation of speed ratio by up to 12.65% and 19.01% in those two driving cycles respectively. The processes determining the speed regulation strategy can provide a new method to formulate the control strategies of CCHMT under different operating conditions particularlly under real-world conditions.

Performance Analysis of a Variable Speed-Ratio Metal V-Belt Drive

1988 ◽  
Vol 110 (4) ◽  
pp. 472-481 ◽  
Author(s):  
D. C. Sun
Keyword(s):  
Operating Conditions ◽  
Computational Scheme ◽  
Optimum Operating ◽  
Speed Ratio ◽  
Belt Drive ◽  
Variable Speed ◽  
Change Effect ◽  
Multiple Band ◽  
Ratio Change ◽  
Metal Block

A model of the metal V-belt drive (MBD), considering its detailed multiple-band and metal-block structure, and the ratio-change effect during its operation, is constructed and analyzed. A computational scheme is devised that adapts the analysis to the computation of the MBD’s performance for any specified drive-schedule. General performance characteristics of the MBD and an example illustrating its response to a given drive-schedule are presented. The use of the analysis and the computational scheme in the design of the MBD and in finding the optimum operating conditions is discussed.

scholarly journals High-frequency power loss mechanisms in ultra-thin amorphous ribbons

2021 ◽  
Vol 519 ◽  
pp. 167469
Author(s):  
Ansar Masood ◽  
H.A. Baghbaderani ◽  
K.L. Alvarez ◽  
J.M. Blanco ◽  
Z. Pavlovic ◽  
...  
Keyword(s):  
High Frequency ◽  
Power Loss ◽  
High Frequency Power ◽  
Amorphous Ribbons ◽  
Frequency Power ◽  
Loss Mechanisms

Design of Multi-Recess Hydrostatic Journal Bearings for Minimum Total Power Loss

1974 ◽  
Vol 96 (1) ◽  
pp. 226-232 ◽  
Author(s):  
C. Cusano ◽  
T. F. Conry
Keyword(s):  
Rotational Speed ◽  
Power Loss ◽  
Load Capacity ◽  
Maximum Load ◽  
Journal Bearings ◽  
Design Criterion ◽  
Total Power ◽  
Eccentricity Ratio ◽  
Constant Ratio ◽  
Design Charts

The design problem is formulated for multi-recess hydrostatic journal bearings with a design criterion of minimum total power loss. The design is subject to the constraints of constant ratio of the recess area to the total bearing area and maximum load capacity for a given recess geometry. The L/D ratio, eccentricity ratio, ratio of recess area to total bearing area, and shaft rotational speed are considered as parameters. The analysis is based on the bearing model of Raimondi and Boyd [1]. This model is generally valid for low-to-moderate speeds and a ratio of recess area-to-total bearing area of approximately 0.5 or greater. Design charts are presented for bearings having a ratio of recess area-to-total bearing area of 0.6 and employing capillary and orifice restrictors, these being the most common types of compensating elements. A design example is given to illustrate the use of the design charts.

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