Abstract: The invention relates to a winding piece (1), in particular in the shape of a hairpin, which is provided to be inserted into the grooves (7) of an electrical machine, comprising two limbs (2) and a curved transition region (3), which connects the two limbs (2) to each other. According to the invention, the limbs (2) each have a first portion (4) having a profile, which is adjusted to the cross-section of the groove (7), and an end portion (5), which has a round profile, wherein the winding piece (1) is formed as a hollow conductor, which has a penetrating channel (9), through which a coolant can be led.

Abstract: A connecting piece for connecting a hollow electric conductor and a coolant line includes a fluid-tight housing (1) having a hollow inner space; a hollow conductor opening (2) in the housing (1); a coolant line opening (3) in the housing (1); and an electrically insulating separating element (4). The inner space hydraulically connects the hollow conductor opening (2) and the coolant line opening (3). The housing (1) includes a coolant line-side housing part (5) and a hollow conductor-side housing part (6). The separating element (4) is arranged between the coolant line-side housing part (5) and the hollow conductor-side housing part (6), and has a coolant channel (7). The separating element (4) is formed as a ball.

Abstract: An electrical hollow conductor (1) in the shape of a tubular body (2) having a hollow interior (3) for continuously winding an electromagnetic coil, wherein the body (2) comprises an electrically conductive material, has an outside diameter and an inside diameter, wherein a ratio of the outside diameter to the inside diameter is in a range of 1.25:1 to 4:1, and is coated with an electrically insulating layer (4) on an outer casing surface of the body (2) and wherein the interior (3) is configured so that it hydraulically or pneumatically connects a first open end of the body (2) and a second open end of the body (2).

Abstract: This invention relates to an electrical hollow conductor (1) in the shape of a tubular body (2) having a hollow interior (3) for continuously winding an electromagnetic coil, wherein the body (2) comprises an electrically conductive material, has an outside diameter and an inside diameter, and is coated with an electrically insulating layer (4) on an outer casing surface of the body (2) and wherein the interior (3) is configured so that it hydraulically or pneumatically connects a first open end of the body (2) and a second open end of the body (2). In order to specify an electrical hollow conductor (1) that can be used for small and mid-sized electromagnetic machines, this invention proposes that a ratio of the outside diameter to the inside diameter is in a range of 1.25:1 to 4:1. This invention further relates to a use of the electrical hollow conductor (1), a connecting piece for the electrical hollow conductor (1), and an electromagnetic machine that has the electrical hollow conductor (1).