A combined cam shaft assembling method comprises the following steps: A, grinding the outer diameter of a steel pipe (2) to specified precision, and machining an inner hole of a cam sheet (1) and a signal disc to specified precision; B, pre-installing the cam sheet (1) and the signal disc onto the steel pipe (2) according to a specified sequence, distance and angle; C, utilizing a tension part (3) to penetrate through the steel pipe (2), ensuring the steel pipe (2) to be expanded, so as to fix the cam sheet (1) and the signal disc onto the steel pipe (2) and reach a specified torque. The method is carried out through a combined cam shaft assembling device. By adopting the tension part (3) to expand the steel pipe (2), the steel pipe (2) and the cam sheet (1) can be rapidly combined, the cam sheet (1) and the signal disc can be clamped onto the steel pipe (2) in a more reliable manner, and the strength of the entire cam shaft is relatively high.

The present invention provides a camshaft capable of suppressing an increase in the number of parts and the number of places to be processed, preventing scratching on a sliding surface that is a part of an outer peripheral surface of an outer shaft and on which an inner cam is rotated, and preventing occurrence of deformation in the entire camshaft after final assembly. A camshaft includes an inner cam that is attached from a radial direction of an outer shaft and that is fixed to an inner shaft with a pin inserted into the inner cam from the radial direction of the outer shaft in a cam surface of the inner cam.

A support tube for a camshaft may include at least one setting region for setting at least one component and a free region adjoining the setting region. The support tube may further include a tube wall that has a varying thickness. In the setting region, the tube wall may exhibit a wall thickness that is greater than the wall thickness of the tube wall in the free region. Furthermore, a method for producing such a support tube may involve forming a profiled strip material with varying wall thickness into the support tube. In some cases the tube wall of the support tube may be hydroformed.

A method for jointing elements, each having a cutout, on a shaft by a device for producing a control shaft, comprises disposing the elements vertically above one another, aligned, and fixed. The method also comprises pushing the shaft in vertically from above though the cutouts of the elements by a traversable guide carriage of the device and displacing by a pneumatic piston of the device the traversable guide carriage and the shaft attached thereto until a maximum first press-in force is reached. The method further comprises displacing by at least two spindles of an electric spindle drive of the device the traversable guide carriage and the shaft when the maximum first press-in force is exceeded.

A segment adapted to be mounted on a shaft to form a camshaft, wherein the segment comprises a through hole adapted to receive the shaft, and wherein the shape of the hole in the segment is adapted to the cross section of the shaft in such a way that when mounted, the segment has a strain causing it to exert a radial load on the shaft in at least two contact points, wherein an inner surface of the hole has at least one deviation to create at least three contact points between the segment and the shaft, and wherein the at least three contact points are non-uniformly distributed about the circumference of the hole. Advantages include that the camshaft can be made lightweight, with less difficulties and at a lower cost as well as with increased precision in angular positioning of the segment on the shaft.

A camshaft-manufacturing method includes: a split die group preparation step; a processing preparation step of preparing a cam including a through-hole, a cam body which is smaller than each of the cam accommodation portions, and ribs which are provided on both sides in a thickness direction of the cam body and configured to be fitted into the rib accommodation portions, and a hollow shaft, accommodating the cam body in the cam accommodation portion and fitting the ribs in the rib accommodation portion, and inserting the hollow shaft into the through-hole of the cam; and a processing step of performing hydroform processing, and fixing the cam to the hollow shaft by expanding the hollow shaft.

A method for obtaining a camshaft for an internal-combustion engine having a structure made of a single piece includes obtaining the camshaft by starting from a metal tubular element. The cams are obtained by expanding the tubular element within a die using high-pressure fluid. The tubular element can have an enlarged thickness in portions that are to form the cams. Forming with high-pressure fluid can be obtained using gas or liquid (for example, water or oil) at high pressure, at room temperature or at a higher temperature. The piece obtained is subjected to thermal treatment and to a grinding operation.

The present invention provides a camshaft capable of suppressing an increase in the number of parts and the number of places to be processed, preventing scratching on a sliding surface that is a part of an outer peripheral surface of an outer shaft and on which an inner cam is rotated, and preventing occurrence of deformation in the entire camshaft after final assembly. A camshaft includes an inner cam that is attached from a radial direction of an outer shaft and that is fixed to an inner shaft with a pin inserted into the inner cam from the radial direction of the outer shaft in a cam surface of the inner cam.

A method and a device may be used to assemble an adjustable camshaft that includes a shaft segment with an inner shaft that extends concentrically through a through-hole of an outer shaft. The method may involve prepositioning the inner shaft by at least partially introducing the inner shaft eccentrically into the through-hole of the outer shaft. The method may further involve introducing a positioning element in an introduction direction through a first outer shaft hole formed in a peripheral wall of the outer shaft, through an inner shaft hole that extends orthogonally to a longitudinal axis of the inner shaft, and through a second outer shaft hole formed in a peripheral wall of the outer shaft such that the positioning element projects out of the second outer shaft hole. Further, the inner shaft may be finally positioned, wherein the positioning element is moved counter to the introduction direction such that the inner shaft is orientated concentrically inside the through-hole of the outer shaft.

A method for assembling a module for a motor vehicle engine in which the components, such as e.g. cams, sensor wheels etc., which are to be attached to the support shaft, are positioned, prior to insertion of the support shaft, merely at those axial positions that do not correspond to the axial positions occupied by these components on the fully constructed camshaft.