Repair and restoration of shafts, couplings, splined and keyed joints

The article provides an overview of the methods of restoration and repair of various parts of the equipment: shafts, couplings, splined and keyed joints. Recommendations on the choice of methods, equipment and tools are given. In case of wear, the keyway is repaired by welding the face with subsequent milling. At the same time, the keyway size set by the standard is maintained. Such repairs are also possible: the keyway is expanded and deepened, completely eliminating the traces of wear, after which a stepped key is made to it. However, with such repairs, a high-quality connection is not provided and, therefore, it is used in exceptional cases (during inspections and ongoing repairs). When repairing keyed joints, the worn keyed joints are not repaired, but new ones are made, fitting them to achieve a firm contact with the side surfaces of the grooves of the connected parts. The exception is the taper keys: they are driven into the keyway with a hammer blow so that they are jammed in height. The taper key should also be hammered in such a way that, when loosened, it can be deposited. Between the head of the key and the end of the part, there must be a distance equal to the height of the key. The connection with the help of splines is used for fixing gears, gear wheels, and bushings on the shafts. It has a number of advantages over other types of connection. The component parts of this joint are more easily centered. This significantly reduces mechanical deformations at the bushing boundary. During operation, under the influence of various loads, the spline joint loses its properties. In this case, the splines or grooves in which they are placed are restored. Splines of small rollers are usually not repaired; the parts with worn splines are mostly replaced with new ones. Such work is carried out in specialized workshops. In some cases, the repair and restoration of such products is carried out in a small workshop, but equipped with the necessary machines.

Development of technique for determining of stamping hammer blow efficiency

The multiple-stage process of large-sized turbine blade blanks on steam-air die-forging hammer is considered. Mathematical modelling of the stamping process of large-sized turbine blade on falling parts 25 t mass stamping hammer is carried out. Measurements of the number of hammer blows and the under-stamping of blade blanks at each stage of the technological process are performed. Method for determining of the hammer blow efficiency is developed. Diagram of the force—displacement of falling parts 25 t mass hammer is constructed. The dependence of the blow efficiency of falling parts 25 t mass hammer is obtained, with can be used in mathematical modelling of the stamping processes of large-sized forgings on this hammer.

Between Life, the Curve and the Hammer Blow: Family, Poverty and Abandonment in the Time of COVID-19 in Lima, Peru

The COVID-19 pandemic brought anxiety, contagion and death to Peru, which registered 288,477 cases after the first 100 days of the outbreak, leading to a state of emergency. The quarantine measures and mobility restrictions characterized as the “hammer blow” produced significant impacts on the most vulnerable and poor populations across the country. While the Peruvian government implemented a subsidy that augmented social welfare programs, unfortunately many poor families and independent workers were left out. The resulting impact of COVID-19 and the quarantine measures has exacerbated existing inequalities in Peruvian society, particularly along the lines of gender and class. This article uses extensive survey and other data from the city of Lima to analyze the social experience of the pandemic from the perspective of the family, the impact of the pandemic on the domestic economy and household management, and finally the dilemmas of care and routines within families.

Indebtedness and redemption

This chapter initiates the series of central studies which address issues related to some four centuries of poetry and money. It considers the metaphorical use of monetary and financial ideas in seventeenth-century secular and sacred poetry with a coda about an eighteenth-century elegy, focusing its discussion upon Christ’s driving the moneychangers from the Temple. Financial metaphors are identified and interpreted in Jonson’s ‘On My First Son’, in various of Shakespeare’s Sonnets, in Donne’s ‘Love’s Usury’, and poems from Herbert’s The Temple. Taking a hint from Donne’s comment on how the last line of a poem ‘mints’ the verse like a hammer blow, it compares and contrasts the forms of ending that these poems achieve. The chapter concludes with a discussion of the role played by allusion to Parable of the Talents in ‘On the Death of Dr Robert Levet’.

Small bowel perforation following blunt abdominal trauma caused by an accidental hammer blow: A case report

Introduction. Trauma is among the leading causes of death. Undetected and untreated adequately and on time, traumatic small bowel injuries can be lethal. Case Report. We present a case of a small bowel perforation after a blunt abdominal injury, caused by an accidental self-inflicted hammer blow to the abdomen. The initial abdominal and chest x-rays and abdominal ultrasound did not indicate an injury to the abdominal organs. Due to the impaired clinical picture and the fact that the patient was hemodynamically stable, multi-detector computed tomography of the abdomen and small pelvis was performed, showing intraperitoneal free fluid and pneumoperitoneum, not seen by other imaging methods. A decision for surgical treatment was made. The intraoperative finding confirmed a small bowel perforation. Conclusion. Due to the possible false-negative imaging findings, clinical follow-up of patients with abdominal trauma is mandatory when making the decision for surgical treatment.