58results about How to "Large pitch" patented technology

The invention discloses a medical connecting device. The medical connecting device has a near end and a far end and comprises an insulating layer and a spiral tube, wherein the insulating layer coversthe outermost layer of the whole device; the spiral tube is of a conductive hollow tubular structure and has a spiral structure; and the spiral structure has a screw pitch gradually changing from thenear end to the far end. According to the medical connecting device, the functions of electric conduction, liquid passing, powder spraying, negative pressure suction, sealing, insulation, supportingand the like can be integrated.

The invention discloses an ultrafine grain rolling method of a large-size 45 steel bar, and relates to the field of machining, particularly to the ultrafine grain rolling method of the large-size 45 steel bar. The ultrafine grain rolling method comprises the following steps of design of rolling tools, specifically comprising design of rollers and design of guide plates: setting the rollers as double-curved surface circular table rollers, specifically, forming generatrices of the rollers through connecting two curves, and setting one surfaces of the guide plates as curved surfaces; constructionof a deformation zone: oppositely placing the curved surfaces of the two guide plates, placing the two rollers between the guide plates, and setting a region refined by the two guide plates and the two rollers as the deformation zone; and selection of rolling feeding manner: selecting reverse feeding rolling manner, and constructing an even-ovality deformation zone. According to the ultrafine grain rolling method of the large-size 45 steel bar provided by the invention, the double-curved surface circular table rollers and the curved surface guide plates are designed, the even-ovality deformation zone is constructed, and severe plastic deformation under the precondition of the Mannesmann effect of a central part can be remarkably inhibited.

The invention provides a trailer arm assembly belonging to the technical field of vehicle dragging devices and solving the problem of poor stability of the existing trailer arm. The trailer arm assembly is characterized by comprising a connecting arm, a supporting arm, a main ball head and an auxiliary ball head, wherein the supporting arm is connected with the connecting arm, and a mounting hole is formed in the supporting arm; the main ball head is provided with a cylindrical extension part inserted to the mounting hole; and the auxiliary ball head is provided with a mounting part which is inserted to the extension part and is in threaded connection with the extension part. The trailer arm assembly has the advantages of simple structure, connection firmness and good stability.

The invention discloses an ultra-fine grain rolling method of a large titanium alloy bar and relates to the field of machining, in particular to the ultra-fine grain rolling method of the large titanium alloy bar. The ultra-fine grain rolling method of the large titanium alloy bar comprises the following steps that rolling tools are designed, roller design and guide plate design are included, eachroller is designed into a double-curved face type circular truncated cone roller, and specifically, a bus of each roller is formed by connecting two curves, and one face of each guide plate is designed into a curved face; a deformation zone is configured, wherein the curved faces of the two guide plates are oppositely arranged, the two rollers are arranged between the guide plates, and a regiondefined by the two guide plates and the two rollers is the deformation zone; an equal ovality deformation zone is configured, wherein ovality in the deformation zone is kept unchangeable; and a rolling feeding manner is selected, wherein a backward advancing rolling manner is adopted. According to the ultra-fine grain rolling method of the large titanium alloy bar, by designing the double-curved face type circular truncated cone rollers and the curved face-shaped guide plates and configuring the equal ovality deformation zone, intensive plastic deformation can be generated on the promise of remarkably restraining a Mannesmann effect of the heart.

The invention relates to a reverse cone spiral roller ultra-fine grain rolling method of a large-size aluminum alloy bar, and relates to the field of mechanical processing. The method includes the following steps that a rolling tool is designed, wherein roll design and guide plate design are specifically included, and rollers are arranged to be double curved surface type circular-table-shaped spiral rollers; a deformation zone is constructed, wherein the curved surfaces of two guide plates are oppositely arranged, the two rollers are placed between the guide plates, and an area defined by thetwo guide plates and the two rollers is the deformation zone; an equal-ovality deformation zone is constructed, wherein the ovality in the deformation zone remains unchanged; and a rolling feeding mode is selected, wherein a reverse rolling mode is adopted. According to the reverse cone spiral roller ultra-fine grain rolling method of the large-size aluminum alloy bar, the double curved surface type circular-table-shaped spiral rollers and the curved surface guide plates are designed, the equal-ovality deformation zone is constructed, and acute plastic deformation is generated on the premise that the heart Mannesmann effect is significantly suppressed.