Pin-bush Research Articles

Experimental study of pin surface precision on lubrication behavior of pin–bush pairs in industrial roller chains

PurposeThe purpose of this paper is to study the influence of surface precision on the lubrication state of the roller chain under adequate and rare oil supply conditions, respectively.Design/methodology/approachThe straightness error and roughness error of the pin generatrices were measured and the influence of surface precision on the lubrication behavior under steady state and reciprocating motion was studied through optical interference experiments.FindingsThe lubrication state is strongly influenced by the surface precision of the roller surface both under adequate oil supply and rare oil supply conditions.Originality/valueIn industrial applications, the machining errors of parts cannot be completely eliminated. Studying the influence of the surface precision on the lubrication behavior of pin–bush pairs can provide the experimental basis for the optimal design of the bush roller chains.

Design and fabrication of electromagnetic braking system for four wheeler


 
 
 These brakes designed by controlling for equipment, automobiles and movers are suitable for AC&DC power supplies up to 12 v to 220 v and are suitable for wide range of drum sizes 10 to 380 mm dia these brakes are suitable with a rated torque ranging from 100kg-cm for the smallest brake up to 2000 kg-cm for a 380mm dia at 50% coil rating, the coil remains in circuit for a maximum 5 min out of every 10min. Since these brakes are closed position, the release of brake shoes is affected by energizing the electromagnetic coil which over comes the spring force and shoes are moved clear of drum by lever system so that the drum is free to rotate without any friction. When the power given to the electromagnetic coil the coil gets energized and in turns the plunger pulls down. The plunger in turn operates the arm of the brake and the brake opens. When specied brake drum both pin bush type and flexible geared type can be supplied along with the brakes.
 
 

Design, analysis and verification of a knee joint oncological prosthesis finite element model

BackgroundThe aim of this paper was to design a finite element model for a hinged PROSPON oncological knee endoprosthesis and to verify the model by comparison with ankle flexion angle using knee-bending experimental data obtained previously. MethodVisible Human Project CT scans were used to create a general lower extremity bones model and to compose a 3D CAD knee joint model to which muscles and ligaments were added. Into the assembly the designed finite element PROSPON prosthesis model was integrated and an analysis focused on the PEEK-OPTIMA® hinge pin bushing stress state was carried out. To confirm the stress state analysis results, contact pressure was investigated. The analysis was performed in the knee-bending position within 15.4–69.4° hip joint flexion range. ResultsThe results showed that the maximum stress achieved during the analysis (46.6MPa) did not exceed the yield strength of the material (90MPa); the condition of plastic stability was therefore met. The stress state analysis results were confirmed by the distribution of contact pressure during knee-bending. ConclusionThe applicability of our designed finite element model for the real implant behaviour prediction was proven on the basis of good correlation of the analytical and experimental ankle flexion angle data.

A study of contact non-linearities in pin-loaded lugs: Separation, clearance and frictional slipping effects

Pin-loaded lugs with bush fitting are widely encountered in industrial applications to connect parts and transmit loads and motions. Due to their mechanical function, frictional contact inevitably takes place on the pin–bush and lug–pin interfaces, and can lead to non-linear behaviours occurrence under monotonic or periodic loading, such as bush–lug contact separation, pin–bush conforming contact effects in the presence of initial clearance, or bush–lug frictional slipping mechanisms. The aim of this paper is not to present new results of finite element simulations for lugs involving contact with friction but to provide a comprehensive study of those contact non-linearities through a dedicated analytical contact model.

The Determination of Using Limiting Clearance between Crank Pin and Bearing Bush in Volkswagen

Nowadays, the workers in automobile service enterprise use their experience to decide the using limiting clearance between crank pin and bearing bush. It is not enough to be scientific and accurate and it has caused waste on the manpower and financial resources. By using the theory of finite element and getting help from the large analysis software ANSYS, this paper calculated the limiting value of fit clearance between the crank pin and bearing bush scientifically which is in some engines belonged to the vehicle types of Volkswagen. Based on calculation, it has been found that the using limiting value of fit clearance between crank pin and bearing bush was generally small. The analysis and calculation in this paper has guiding significance to the development of automobile maintenance trade.

Experiments on the pressure distribution and frictional torque in articulating pin joints

In its simplest form, aircraft landing gear consists of large structural members connected by pin joints that allow articulation, and hydraulic actuators for deployment. The design of these pin joints is critical to successful operation. In this article, the authors explore two related aspects of pin joint design: first the contact pressure distribution within the joint and second the frictional torque required to rotate the joint. The former is important in stress analysis and the latter in defining the required actuation force. The joint consists of a pin located within four bushes that are fixed into the structural member. Grease is fed into the bearing cavity. A purpose-built test rig was designed and built to hydraulically load and articulate a specimen pin within its bushes. A novel ultrasonic method was used to measure the contact pressure between the pin and bushes when the joint is subjected to a constant radial load. The method is based on recording the proportion of an ultrasonic pulse that reflects from the pin—bush contact. When there is no contact the pulse is fully reflected and when contact takes place the pulse is partially reflected. The proportion of the pulse reflected depends on the conformity of the surfaces and hence the contact pressure. The pressure profiles measured in this way were found to be approximately cosinusoidal, extending over an arc of±60° regardless of the radial load. The rotational torque and angular displacement were also measured during joint articulation cycles for a range of applied lateral pin loads. The results showed that articulation torques ranging from 20 to 150 kN m were required to rotate the pin as the lateral load was increased from 5 to 40 kN. An estimate of the friction coefficient between pin and bush can be obtained directly from this lateral load and torque data. However, an improved measurement, which includes the effect of the radial component of the lateral loading force, was obtained by combining the pressure distribution data with the torque data. Friction coefficients in the range 0.08–0.11 were deduced in this way and were found to increase slightly with load. This indicates that the joint operates in boundary-lubricated regime and that grease entrainment is an important factor.

Wear of Thermochemically Produced Nitrogen Stainless Steel

Thermochemically produced stainless steels with varying nitrogen content were slid dry on high carbon martensitic steel counterfaces using a pin bush machine. The running-in wear was high but the steady state wear decreased with increased nitrogen contents of the steels. A work hardened layer formed on the pins, the degree of hardening increasing with the nitrogen content of the steels. The hard pins caused a considerable amount of wear of the bushes, possibly, by ploughing. The pins wore by transfer and oxidation and, by interfacial shear and, probably, brittle fracture of the work hardened layer at a heavy load.