This paper proposes the lubrication characteristics of the worn slipper in the slipper–swashplate pair. The mathematical analysis of lubrication characteristics of slipper with…
Abstract
Purpose
This paper proposes the lubrication characteristics of the worn slipper in the slipper–swashplate pair. The mathematical analysis of lubrication characteristics of slipper with the measured surface roughness distribution is introduced. Based on the results from the test rig, it carries out the result compassion in different operating conditions.
Design/methodology/approach
This paper introduces the measured surface roughness distribution of new and used slippers and generates the oil film thickness distribution with it. An average flow Reynolds equation of the pressure distribution is introduced too. The experimental results are carried out on a novel adjustable oil film thickness test rig.
Findings
The surface roughness of the worn slipper enlarges the reacting force and torque only if the oil film thickness is small. When the ratio of oil film thickness to the root mean square of surface roughness is much smaller than 3, the influence of it on torque is obvious.
Originality/value
Different surface roughness of worn slipper proposed in this paper has an influence on the lubrication characteristics. As the slipper is worn after a period of use, the changed lubrication characteristics should be considered in the slipper design.
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This paper aims to propose the slipper/swash plate pair loaded with a step motor-spring mechanism to reduce the energy consumption under different rotating rate conditions. The…
Abstract
Purpose
This paper aims to propose the slipper/swash plate pair loaded with a step motor-spring mechanism to reduce the energy consumption under different rotating rate conditions. The relationship between the operating conditions, oil film thickness and energy consumption is analyzed. The system dynamic model of the slipper/swash plate pair loaded with a step motor-spring mechanism is introduced. Based on the results of the experiment, the PI controller and step motor-spring mechanism are useful for reducing energy consumption.
Design/methodology/approach
This paper introduces the energy consumption of the slipper/swash plate pair. A system dynamic model of the slipper/swash plate pair loaded with a step motor-spring mechanism is introduced too. In the experiment, three step motor and S-type force sensor are used to control the oil film thickness.
Findings
PI controller and the step motor-spring mechanism are useful for controlling the oil film thickness and reducing the energy consumption under different rotating rate conditions. The accuracy of the oil film thickness control is acceptable and the response time is a bit long
Originality/value
PI controller and the step motor-spring mechanism are useful for controlling the oil film thickness and reducing the energy consumption under different rotating rate conditions. The accuracy of the oil film thickness control is acceptable and the response time is a bit long.
Details
Keywords
The purpose of this paper is to propose an adjustable oil film thickness test rig for detecting lubrication characteristics of the slipper. The mathematical analysis of…
Abstract
Purpose
The purpose of this paper is to propose an adjustable oil film thickness test rig for detecting lubrication characteristics of the slipper. The mathematical analysis of lubrication is introduced. Based on the results from the test rig, the results comparison from test rig and mathematical analysis is carried out.
Design/methodology/approach
This paper introduces a mechanism which can adjust the oil film thickness between the slipper and swash-plate. Feasibility is ensured, and the accuracy of test rig is guaranteed by the three-coordinate measuring machine. Three displacement sensors show the oil film thickness and its shape. The reacting force and torque resulting from oil film can be achieved by three S-type force sensors and a torque sensor, respectively.
Findings
The relative error of the reacting force is small. The relative error reduces and is acceptable when the deformation of retainer is taken into account. The thickness and tilt angle of oil film have less effect on the reacting force. However, they are significantly impact on torque.
Originality/value
The test rig proposed in this paper is able to adjust the oil film thickness, which is used to detecting the lubrication characteristics in pump design.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0166/
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This paper aims to carry out a thermal-hydraulic simulation model for pump and hydraulic system to predict the temperature increasing and pump performance. Based on the model, how…
Abstract
Purpose
This paper aims to carry out a thermal-hydraulic simulation model for pump and hydraulic system to predict the temperature increasing and pump performance. Based on the model, how to alleviate the temperature is introduced. Besides, the optimization of piston is carried out.
Design/methodology/approach
This paper analyzes the heat generation in lubricating interfaces of the pump with energy conversion theory. The heat transfer inside the pump is analyzed with the control volume method. The simulation model is constructed in AMESim because of its operating friendly nature. The experiment is carried out to prove the validity and accuracy of the simulation model.
Findings
Temperature has less effect on the mechanical loss of pump. However, it has a great impact on volumetric efficiency. To reduce the temperature on the piston surface, the size of the piston should be optimized.
Originality/value
This paper fulfills a novel thermal-hydraulic model to evaluate the temperature of the pump. Based on the model, the performance of the pump is determined and optimization is carried out.
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This paper aims to investigate the probability of unacceptable consequences from structural fire damage in a typical Scandinavian single-story steel frame building and discusses…
Abstract
Purpose
This paper aims to investigate the probability of unacceptable consequences from structural fire damage in a typical Scandinavian single-story steel frame building and discusses it in relation to life safety. This paper is a complement to the paper “Life safety in single-story steel frame buildings, Part I – deterministic design” by Sandström (2019) which considers the same design philosophy but with a probabilistic design approach.
Design/methodology/approach
The reliability of a single-story steel frame building is investigated by using crude Monte Carlo simulation by including consideration to the fire conditions.
Findings
The investigated building does not meet the safety levels as stipulated by EN 1990 for structural fire damage. However, by including consideration to the fire conditions in the compartment, it is shown that the life safety objective is not compromised by the structural fire damage, i.e. the structure remains intact as long as any individuals/firefighters can survive within the fire area compartment.
Originality/value
This paper presents practical application of a conceptual paper presenting a general approach to structural fire safety design and the life safety objective.
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Changlong Ye, Yunfei Zang, Suyang Yu and Chunying Jiang
The purpose of this paper is to demonstrate a multipurpose inspection robot that can both walk on the ground and climb on poles. The structure design, size optimization…
Abstract
Purpose
The purpose of this paper is to demonstrate a multipurpose inspection robot that can both walk on the ground and climb on poles. The structure design, size optimization, kinematics analysis, experiment and arithmetic of the robot are discussed in the paper.
Design/methodology/approach
The robot consists of three adjustable modules and a two-degree-of-freedom parallel mechanism in tandem, and the wheel-finger mechanism of each module can realize wheel-finger opening and closing for fast movement and obstacle crossing. This paper uses geometric analysis and simulation analysis to derive size optimization, and vector coordinate method to derive kinematics. Finally, the experiment is carried out by simulating the working environment of the robot.
Findings
The robot can realize ground walking and ground turning through the robot entity prototype experiment on the built working environment and efficiently realize 0°–90° pole climbing by the assemble design, optimization and machining. In addition, the robot can also smoothly complete the state transition process from 0° ground to 90° pole climbing. Furthermore, the robot shows good environmental self-adaptation and can complete daily inspection work.
Originality/value
The robot can pitch and yaw at a large angle and has six-legged characteristics. It is a multipurpose inspection robot that can walk on the ground and climb on poles. And through structure design, size optimization, kinematics analysis and simulation, the existing robots’ common shortcomings such as poor barrier-crossing ability and poor environmental adaptability are solved.