The diaphragm bellows includes a plurality of diaphragms (1) with outer edges (3) and inner edges (2), wherein diaphragms (1) that follow one another in the direction of the central longitudinal axis (5) of the diaphragm bellows are welded together alternately in the region of their inner edges (2) and in the region of their outer edges (3). A sliding-guidance device of the diaphragm bellows has at least two ring parts (10, 11). The at least two ring parts (10, 11) each extend through at most 180 in the circumferential direction about the longitudinal axis (5) of the diaphragm bellows and each have a guide portion (12) and a holding portion (13) protruding from the guide portion (12) in the direction of the longitudinal axis (5), the holding portion (13) projecting into an intermediate space (6) located between two adjacent diaphragms (1). The guide portion (12) extends radially outside the two adjacent diaphragms (1) between which the holding portion (13) projects, and has a guide face (16), directed away from the longitudinal axis (5) of the diaphragm bellows, for sliding guidance on the inner surface (15) of a tube (14) surrounding the diaphragm bellows at least along a part of its longitudinal extent.

The diaphragm bellows includes a plurality of diaphragms (1) with outer edges (3) and inner edges (2), wherein diaphragms (1) that follow one another in the direction of the central longitudinal axis (5) of the diaphragm bellows are welded together alternately in the region of their inner edges (2) and in the region of their outer edges (3). A sliding-guidance device of the diaphragm bellows has at least two ring parts (10, 11). The at least two ring parts (10, 11) each extend through at most 180 in the circumferential direction about the longitudinal axis (5) of the diaphragm bellows and each have a guide portion (12) and a holding portion (13) protruding from the guide portion (12) in the direction of the longitudinal axis (5), the holding portion (13) projecting into an intermediate space (6) located between two adjacent diaphragms (1). The guide portion (12) extends radially outside the two adjacent diaphragms (1) between which the holding portion (13) projects, and has a guide face (16), directed away from the longitudinal axis (5) of the diaphragm bellows, for sliding guidance on the inner surface (15) of a tube (14) surrounding the diaphragm bellows at least along a part of its longitudinal extent.

A reciprocating pump includes a housing, a rod, and a bellows. The housing surrounds a bellows chamber and a displacement chamber. A portion of the rod extends through the opening in the endcap and into the bellows chamber of the housing. A cross-section of the rod includes a lobed shape. The bellows is connected to the housing and to the rod such that the bellows surrounds a portion of the rod.

A boot of the present invention is a boot that is formed into a cylindrical shape that is extendable and contractible in an axis direction and can be mounted to a mounting portion O1 of a mounting target object O by injecting fluid inside the boot by a fluid injecting unit FI, wherein the boot 1 comprises an annular mounted portion 11 that is provided on one end 1a side in the axis X direction and is to be mounted to the mounting portion O1, an abutting portion 12 that is provided on an other end 1b side in the axis X direction and onto which a tip FIa of the fluid injecting unit FI can abut toward the one end la side in the axis X direction along the axis X direction, and an extendable/contractible portion EC that extends along the axis X direction between the mounted portion 11 and the abutting portion 12, and wherein the abutting portion 12 extends along a radial direction on the other end 1b side of the boot 1 in the axis X direction of the boot 1, is formed into an annular shape along a direction around the axis of the boot 1, and is provided, on an inner side in the radial direction of the abutting portion 12, with an opening 12a that allows fluid communication between the inside and the outside of the boot 1. With such a structure, it is possible to provide a boot that can be easily mounted to the mounting portion of the mounting target object.