Abstract: A camshaft for automotive engines in particular having contra-rotating cams capable of rotating over a limited circumferential angle about the camshaft axis in which an inside shaft (2) and an outside shaft (1) are arranged concentrically one inside the other, the contra-rotating cams (3, 4) include first and second cams, of which the first cam (4) is fixedly connected to the inside shaft, and the second cam (3) is fixedly connected to the outside shaft (1), the outside shaft (1) and the inside shaft (2) are mounted with respect to one another, is to be manufacturable economically and with a high manufacturing precision.

Abstract: An apparatus and method are provided for performing multiple machining operations on a workpiece such as a crankshaft. Oil holes may be drilled in a crankshaft by a tool shifted along a curved path between successive, acute angle tool plunging locations. The tool's carrier is shifted parallel to the crankshaft axis and the tool carrier is rotated to the desired acute angle about a point on the crankshaft axis for each of successive oil hole drilling locations thereby reducing programming needed to drill the oil holes at the specified angles. Offset tolerance errors are reduced by a large factor as the tool is plunged from an outer initial position toward the crankshaft axis.

Abstract: The invention relates to a method of producing a composite shaft comprising a shaft body (1), at least one first component (2, 9) connected to the shaft body (1) in a rotationally fixed manner, and at least one second component (3, 8) rotatable relative to the shaft body (1), in which method the at least one first component (2, 9) and the at least one second component (3, 8) are pushed onto the shaft body and assembled in the intended sequence.

Abstract: In a camshaft adjuster for an internal combustion engine including a housing, with two side cover sections and a middle jacket section arranged between the side cover sections and a rotor disposed in the housing, the jacket section is formed by a cross-cut profile section drawn from a tube in the form of a semi-finished product.

Abstract: A camshaft and a method for manufacturing the camshaft as described. A gear wheel of the camshaft is mounted on a camshaft tube. A collar that is attached to the gear wheel and a locating bearing element that is mounted on the camshaft tube delimit a locating bearing seat of the camshaft.

Abstract: A cam lobe of a camshaft has a base circle portion and a lifting lobe portion. A camshaft journal of the camshaft has first and second bearing portions that bear reaction forces from the base circle portion and the lifting lobe portion, respectively. The first bearing portion has an axial width smaller than that of the second bearing portion with at least a portion of an axial end surface of the first bearing portion facing the cam lobe being disposed away from the cam lobe relative to an axial end surface of the second bearing portion. The base circle portion has an axial width smaller than that of the lifting lobe portion with at least a portion of an axial end surface of the base circle portion facing the camshaft journal being disposed away from the camshaft journal relative to an axial end surface of the lifting lobe portion.

Abstract: The present invention relates to a method of forming a cam shaft by assembling a preliminary shaft (10) having a predetermined outer diameter and a cam lobe (20) including a cam-lobe shaft hole (21) having a diameter larger than the outer diameter of the preliminary shaft (10).

Abstract: The present invention relates to an adjustable camshaft in which an inside shaft and an outside shaft, each being fixedly connected to cams, are mounted so they are rotatable in relation to one another. To produce the relative movement, a hydraulic adjusting mechanism is provided on one of the ends thereof; in the adjusting mechanism, first and second rotatable adjusting elements are each fixedly connected to one of the two shafts opposite one another. Adjacent to the adjusting mechanism, the outside shaft is fixedly connected to a first bearing ring supporting at least the outside shaft in a stationary first abutment.

Abstract: The present invention is a novel non-splined shaft for connecting cam units (cam sections) in a series to construct a camshaft having zero degree backlash for use within an engine. Such engines typically use a camshaft comprised of a plurality of separate camshaft units (cam sections) which are connected in a series by one or more cam connecting shafts. The entire series of camshaft units and cam connecting shafts may be, for example, 40 feet in length. Examples of natural gas engines in which the cam connecting shafts described herein may be used include, but are not limited to, the INGERSOLL-RAND KVR and KVT series of engines.

Abstract: The invention relates to a camshaft (50) comprising a shaft (13) onto which one or more annular cams (46?) are pushed and fixed in a positive and/or non-positive fit. To produce said camshaft in a particularly cost-effective, simple and flexible manner, the cams (46?) are produced from one or more strip sections by deformation, in particular by bending into an annular form and by the welding of the free ends.

Abstract: The invention relates to an internal combustion engine (1) comprising a housing (2) having at least one opening (4) into its inside, which is preferably the engine-oil feed inlet, and with a camshaft (5), mounted inside the housing for rotation about its geometric shaft. The camshaft (5) and the housing (2) have means cooperating with each other and with a device for locking a turnable shaft (6) with respect to the housing, insertable through this opening. In a second embodiment of the present invention, the device consists of a rod (6), the cooperating means in the housing consist in a bore (7) for receiving an end of the rod (6), and the cooperating means on the cam shaft consist of a notch (9) made in the surface of the shaft, which cooperates with the rod. In this way, when there is a need to adjust, repair and/or replace engine (1) components, the rod (6) is inserted through the opening (4) and locked in this bore (7) of the housing (2).

Abstract: A method for manufacturing cams for composite camshafts with the steps hot-forming a cam 11 such that a cam outside contour is produced and a cam bore 13 is punched and axially and radially calibrating the cam 11, wherein the calibration comprises the steps inserting the cam into an undivided mould 21 that defines the calibrated cam outside contour 12, inserting an arbor 23 into the cam bore 13 that defines the calibrated cam bore 13, and axially shortening the cam 11 between a lower die 22 that is situated between the mould 21 and the arbor 23 and on which the cam 11 lies with a first end face 14 and an upper die 25 that is guided between the mould 21 and the arbor 23 and acts upon the second end face 15 of the cam 11.

Abstract: A cam lobe 22 is formed as a single part, not formed together with a shaft body 21. The shaft body 21 penetrates through bearing holes 13F, 13M, and 13R, as well as a mounting hole 24 provided in the cam lobe 22, which is arranged in between the adjacent bearing holes 13F, 13M, and 13R. The bearing holes 13F, 13M, and 13R each in a perfect circular shape can be achieved, since there is no need to divide the bearing holes 13F, 13M, and 13R into two semi-circular arc shaped concave portions. Consequently, a camshaft 20 can be supported so as to rotate smoothly.

Abstract: A method of manufacturing a cam shaft that prevents cracks during the joining of a cam lobe to a shaft, and improves the degree of freedom of design of the cam lobe is provided. By a method of manufacturing a cam shaft that after an inner circumferential surface 13 of a cam lobe 1 is subjected to treatment for residual compressive stress addition treatment, the cam lob 1 is joined to a shaft, above problem is solved. It is preferred that the residual compressive stress on the inner circumferential surface 13 of the cam lobe 1 is not less than 100 MPa. In addition, an outer peripheral surface 14 of the cam lobe 1 can be also subjected to treatment for residual compressive stress addition treatment. As the treatment for residual compressive stress addition treatment, shot-peening treatment, induction hardening treatment, barrel polishing treatment, carburizing and quenching treatment or carbonitriding treatment is performed.

Abstract: A camshaft has contrarotating cams for automotive engines, in which an inside shaft and an outside shaft are arranged concentrically so they are contrarotating, at least one cam has at least one main cam element that can be placed radially on the outside shaft and is supported there so it can rotate. The main cam element is connected to the inside shaft in a manner that is rotationally locked via a fastener passing through a recess in the outside shaft. Further features include a fastener, a main cam element and a locking means. The fastening of the main cam element to the inside shaft is provided by widening the outside diameter of the fastener by the locking means with a resulting tightly seated connection between the fastener and the inside shaft, and the fastener and the locking means.

Abstract: A method of producing assembled camshafts from a tubular member and components slid on to same and having through-holes and outer functional faces, wherein the components are provided with through-holes which have been machined by non-chip-forming operations and on which an outer contour is preferably finish-machined; wherein the tubular member can be clamped in so as to be centred on a reference axis B; wherein the components are slid on and are centred via their outer contour on the reference axis of the clamping means of the tubular member; wherein, between the through-holes and the tubular member, a compensating and joining gap is provided and wherein; between the components and the tubular member with material being added, a material locking connection or a press fit connection is provided by expanding the tubular member.

Abstract: The invention relates to an internal combustion engine comprising a variable valve drive device provided with at least one camshaft having at least one cam arrangement. Said cam arrangement comprises a cam which can be displaced essentially radially in relation to the camshaft, and at least one, preferably two, base circle disks fixed to the camshaft.

Abstract: A hollow step-profiled shaft such as a cam shaft that is high in accuracy and excellent in productivity and requires little post-machining is being formed. To this end, a hollow stepped shaft 8 having its axis and large diameter portions 9a-12b intermediate axially between its ends is formed by a forming process in which each large diameter portion of the shaft is compressed with forming dies 32a-32d from at least three different directions approximately simultaneously towards the axis to shape the large diameter portion with a profile such as to conform to contours 38a-38d of a cavity 38 formed in a region of tips of the forming dies 32a-32d.

Abstract: A dynamic camshaft apparatus includes, according to one embodiment, a moveable camshaft connected to an engine. The moveable camshaft has a first position when the engine is started and at low RPMs. Further, the moveable camshaft is conformed to move to different positions as the RPMs change.

Abstract: A camshaft for an internal combustion engine includes a cam lobe for actuating a valve. The cam lobe has an opening ramp profile that acts to loft the valve gear away from contact with the cam lobe to a maximum lift of the valve, with the valve gear returning to contact with a closing ramp of the cam lobe sufficiently in advance of a minimum cam lobe closing ramp height so as to dissipate enough closing energy of the valve to minimize valve bounce after the valve contacts a corresponding valve seat.

Abstract: A ductile repair cylinder liner for a diesel engine, the cylinder liner having an additional cooling groove with a parabolic varying cross-section machined into the outer surface of the cylinder liner immediately below the radially extending locating flange for the liner.

Abstract: The invention concerns a method whereby components are arranged in a mounting device, outside an internal high-pressure forming press, in accordance with their position and their function, such that they are linked to one another. The mounting device comprises an upper part and a lower part including cavities identical to the cavities of the internal high pressure tool. Once the components have been installed, the mounting device is introduced in the internal high-pressure press, then the upper part or the lower part of the mounting device is withdrawn, the part of the mounting device remaining in the internal high-pressure press being displaced against the upper tool or the lower tool. For the forming process, the components are maintained in a part of the tool by depression or by clamping, then the part of the mounting device is removed from the internal high-pressure press, thereby ensuring high precision positioning of components. Additionally, the production rate is substantially increased.

Abstract: A method of producing a built shaft in which at least one part, particularly a cam, is mounted on the shaft, particularly a camshaft, includes inserting the shaft into an opening of the part. Before mounting the part, the shaft is stretched by a stretching and tightening device such that an original diameter in the area of at least one fastening location is reduced to a stretched diameter. The part is slid onto the shaft and up to the fastening location. The stretching and tightening device is then loosened to enable the diameter of the shaft to enlarge once more towards its original diameter. The part is firmly fastened at the fastening location by an interference fit in both an axial and rotationally fixed manner.

Abstract: A Method for the linking of cam rings to hollow shafts. In a first process step, the cam rings are manufactured, so as to generate their function-related contour, from two individual rings of different material connected to each other in a force-and form-closing manner, with the material of the outer ring being hard and elastic and having a permissible residual expansion of at least 0.5%, and that of the inner ring being soft and plastically deformable. The cam rings together with the hollow shaft to be deformed are placed into an internal high pressure forming tool in a manner to suit the respective function. In a second process step through the application of an internal high pressure forming process and, due to the internal pressure exerted the cam rings are joined to the hollow shaft in a force-and form-closing manner.

Abstract: The invention relates to a device and method for production of a pre-formed shape on a workpiece having a blank piece shape, by means of grinding in several working steps, preferably on cams of a camshaft, comprising a grinding machine and a controller, for controlling the grinding machine. A measuring device is provided, for measuring the actual blank piece shape of the workpiece before grinding, directly or indirectly connected to the controller by means of a data transmission device such that the measured values, as determined by the measuring device, may be provided to the controller and set points for the control determine from said measured values by the controller.

Abstract: A camshaft assembly 16 is disclosed for an engine 10, along with a method of producing the camshaft 16. The camshaft includes a support shaft 22 that carries in the region of one end 26 a camshaft element. The camshaft element may comprise a rotation sensor target member 24 and the support shaft 22 is preferably a tubular shaft. The camshaft element 24 is captured onto the support shaft 22 by deforming a deformation zone 46 at the end of the support shaft 22 into a radially extending rivet head 28.

Abstract: A valve timing control apparatus includes a driving side rotational member, a driven side rotational member formed with a plurality of recessed portions into which a supporting jig is insertable at a second side thereof in the axial direction, a fluid pressure chamber, a vane, a lock member, and a cover plate formed with a plurality of through holes, through which the supporting jig is insertable, at a position in which each of the plurality of through holes is overlapped with each of the plurality of recessed portions of the driven side rotational member in a condition where the relative rotational phase is restrained at the lock phase.

Abstract: A built multiple cam is disclosed which can be produced at low cost and which can be used in a flexible manner and which requires a small amount of construction space in an axial direction. The built multiple cam comprises the following components: a first partial cam provided with a bore, a cam contour A and a joint contour which is arranged in axial proximity thereto and provided with an outer surface; a second partial cam provided with a bore, a cam contour A and a joint contour which is arranged in axial proximity thereto and provided with an outer surface; a ring which is provided with a cam contour B which is different from cam contour A and an inner contour having an inner surface, wherein the inner surface of the ring can be displaced towards the outer surfaces of the partial cams; and connections which act between the ring and the partial cam ensure a fixed connection between such components. Also disclosed is a method used to produce a built camshaft comprising at least one built multiple cam.

Abstract: In a camshaft for an internal combustion engine having a cam disk support shaft, to which a plurality of cam disks and a drive wheel are attached, the outer radius of the cam disk support shaft varies continuously in those sections in which the cam disks are attached. The cam disks have bores whose inner radius varies continuously and the cam disk support shaft is alternately provided with elevations and depressions in those sections in which the cam disks are attached, the elevations and depressions forming a wedge-shaped curve profile about the circumference of the section of the cam disk support shaft The elevations continuously enlarge the outer radius of the cam disk support shaft, the bores of the cam disks being matched to the enlarged portion of the outer radius of the cam disk support shaft, so that by relative rotation of the cam support shaft and the cam disks and also the drive wheel the components are firmly joined and the camshaft is formed.

Abstract: A camshaft of an automotive engine includes two concentric contra-rotating shafts mounted one inside the other, namely an inside shaft and an outside shaft, at least one cam rotatably mounted on the outside shaft, fixedly connected to the inside shaft radially through the outside shaft via a fastening mechanism, a sleeve gripped by the fastening mechanism and inserted fixedly into aligned boreholes in the inside shaft and in the cam, a core that widens the material of the sleeve within its elasticity limits in the area of the inside shaft and is inserted into the sleeve after insertion of the sleeve into the shaft mechanism. To improve mountability, the core extends over the entire length of the sleeve and widens it beyond the area limited by the inside shaft without exceeding the upper limit of elasticity of the material of the sleeve in comparison with its uninstalled starting state.

Abstract: The invention relates to a system, comprising a camshaft with at least two bearing points, a two-part camshaft receptacle which has, in a lower part, at least two bearing saddles and, in an upper part, at least two bearing covers corresponding to the bearing saddles, the camshaft being mounted with its bearing points in the bearing saddles and bearing covers. Further, bearing half shells are provided, of which in each case two are arranged in pairs between a bearing point and the bearing saddle and bearing cover receiving this bearing point, so that, the bearing half shells are supported on the bearing saddle or bearing cover and in each case two bearing half shells, together with a bearing point form a radial plain bearing.

Abstract: An assembled camshaft (10) for engine includes: a cam lobe piece (12); and a hollow shaft member (11) having at least two shaft fixing surfaces (11A) formed by plasticity process on a portion of the hollow shaft member (11) corresponding to a position between cylinders of the engine.

Abstract: An internal combustion engine including an engine housing having a cam chamber and an aperture providing access to the cam chamber. The engine also includes an insert at least partially made from plastic received within the aperture, a crankshaft coupled to the engine housing for rotation about a crank axis, and a cam shaft defining a cam shaft axis and at least partially made from plastic that is rotatably driven by the crankshaft. The cam shaft includes first and second ends and at least one cam lobe positioned between the ends. The first end is rotatably supported by the engine housing and the second end is rotatably supported by the insert. The engine also includes a metal portion coupled to either the insert or the cam shaft. The metal portion defines a flange having a face in contact with an adjacent surface of the other of the insert and the cam shaft.

Abstract: An adjustable camshaft system for an automotive engine includes a camshaft having machined and fabricated axially-directed control passages combined with an oil-activated camshaft phaser. The fabricated oil control passages are formed within a portion of the camshaft having an outside diameter which is substantially equal to the outside diameter of other portions of the camshaft fitted within bearings carried within the engine's cylinder head.

Abstract: A camshaft is formed at a generally middle portion with an enlarged cylindrical portion. An annular vane member is mounted on the enlarged cylindrical portion and secured thereto by means of a nut. An annular housing or sprocket is arranged to receive therein the annular vane member in a manner to permit a rotation of the vane member relative to the annular housing. Each of a circular opening of the vane member and a circular opening of the annular housing is so sized as to permit cam lobes of the camshaft to pass therethrough.

Abstract: A device for adjusting a camshaft of an internal combustion engine of a motor vehicle has a stator and a rotor fixedly connected to a camshaft and rotatable relative to the stator. A drive wheel is fixedly connected to the stator and is centered by the camshaft. The stator has a peripheral area provided with a centering element interacting with a counter element provided on the drive wheel for aligning the drive wheel in a rotational direction relative to the stator.

Abstract: Disclosed is a camshaft, especially for an internal combustion engine of a motor vehicle, comprising at least one cam that is provided with cam segments (2, 3), which can be displaced relative to each other. The aim of invention is to create a compact camshaft structure while obtaining or ensuring good and stable guidance between the cam segments (2, 3) that can be displaced relative to each other. Said aim is achieved by placing the ends of the U-legs of the second cam segment (3), which has the shape of a horseshoe and is movable while the other cam segment (2) is connected in a fixed manner to the camshaft, entirely within the outer contour of the basic camshaft material located between the U-legs in the radially deployed position of the second cam segment (3), said U-legs resulting from the horseshoe shape of said cam segment (3) and extending in a free manner at the ends thereof.

Abstract: A camshaft for automotive engines in particular, comprising at least one first cam (5?) and at least one cam segment (6) which is rotatable to a limited extent with respect to the first cam (5?) and exercises the full or partial function of a second cam (4), with which an inner shaft (3) and an outer shaft (2) are arranged concentrically one inside the other and also rotatably with respect to one another, the first cam (5?) and the cam element (6) surround the outer shaft (2) on the periphery at least in part, the first cam (5?) is fixedly connected to the outer shaft (2), and the respective cam segment (6) is connected to the inner shaft (3) in a rotationally fixed manner, the cam segment (6) is provided with an inside circumferential surface extending over only a section of the circle running concentrically in a circular cylindrical pattern with respect to the inner shaft (3) and the outer shaft (2), the inside circumferential surface of the cam segment (6) is supported on a guide area (2?) formed by the

Abstract: An adjustable cam shaft includes an elongated shaft which may include multiple shaft sections rotatably coupled to one another. Intake and exhaust cam lobes are carried by the one or more shafts and are selectively rotatable relative to one another and selectively locked in place relative to one another in order to adjust a displacement angle between the cam lobes to alter intake and exhaust timing and other engine characteristics without the need to replace the cam shaft.

Abstract: The invention relates to a camshaft comprising a tubular shaft (1) and cams (2) which are radially disposed thereon. Said cams (2) respectively engage with the shaft in a perfect fit (1) and the free surface (1.1) of the shaft forms the base circle of the cams (2), whereby the cams (2) are respectively engaged in pocket-like recesses of the shaft (1).

Abstract: The invention relates to a method for producing cams (1) for a camshaft. The cams are produced by bending together the ends of long profile strips (4) or by bending and putting together several pieces of profile strips in a circumferential direction. Cams produced in such a way are preferably welded onto the shaft. The invention also relates to suitable welding methods such as resistance welding, laser-beam or electron-beam welding and corresponding devices.

Abstract: The invention relates to a method for assembling a camshaft by using a shaft (10) and a plurality of cams (21–26) comprising respectively an opening for the shaft. According to the invention, the cams are disposed in a tight manner in a storage element (40), in such a way that they are orientated towards each other in a predefined rotative position, the openings thereof for the shaft being orientated in a coaxial manner. The shaft is then introduced into the cam packet and arranged consecutively with respect to each individual cam by displacement in the longitudinal direction thereof. The cams are secured one after the other on the shaft. The required rotation of the cams can be obtained in a simple manner by longitudinal displacement of the shaft and also by optionally rotating the shaft at a certain angle.

Abstract: Hollow shafts, and particularly camshafts, are produced using an internal high-pressure forming (IHF) process. Cams and/or machine elements are mounted at intervals onto the outer surface of the hollow shaft, depending on the use of the latter, by a non-positive and/or positive fit, in a position appropriate to their function when the hollow shaft is placed in the forming tool. An element with approximately the same external diameter as the internal diameter of the hollow shaft is placed in at least one of the hollow shaft, and the hollow shaft together with the cams and/or machine elements that have been pushed onto the same and the inserted element are placed in an IHF tool. Once the IHF tool is closed, the medium is caused to act under the required high-pressure in the hollow shaft. At the same time as the medium is acting internally, at least one ram is pressed axially against at least one front face of the hollow shaft.

Abstract: Camshaft configurations are increasingly more closely assembled in motor vehicle engines such that access to the cylinder head bolts is obstructed. Indentations 2 along built-up camshafts, which comprise a camshaft tube 1 with slid-on camshaft structural components, such as the cams 3, permit through corresponding rotation free access to the cylinder head bolts even after they are in the installed state. In order to be able to employ for the camshaft structure tubular camshafts 1, according to the invention a pressing tool 10 with bottom dies 12, 13 is provided such that during the pressing operation of the indentations, the camshaft tube 1 advantageously is not deformed beyond the original outer diameter d and the camshaft 1 can be assembled advantageously form-fittingly through subsequent sliding-on of the cams 3.

Abstract: A transport and assembly device for assembling a shaft seal, particularly one with a seal lip directed radially toward the inside, into a camshaft arrangement for an internal combustion engine is designed to simplify the assembly of the shaft seal. The device includes a first intake area for the shaft seal, a second intake area for a signal generator wheel, and an installation area for installation onto the camshaft arrangement during assembly.

Abstract: In an arrangement and method for mounting a camshaft onto a cylinder head of an internal combustion engine by camshaft bearings disposed on the cylinder head of the engine camshaft bearing by support seats which are formed integrally with the cylinder head and bearing caps which are formed integrally with a cylinder head cover mounted onto the cylinder head, at least one of the bearings is an assembly bearing with a separate assembly bearing cap that has a bearing opening of a diameter greater than that of the camshaft so that the camshaft when placed onto the bearing seats is not fully moved into the bearing seat openings but is fully engaged with the bearing seats only when the cylinder head cover is mounted onto the cylinder head whereby the camshaft in the assembly bearing is moved out of contact with the assembly bearing cap.

Abstract: A camshaft has a cylindrical shaft (1) and a hollow, cylindrical cam (2). The hollow, cylindrical cam (2) is pushed onto the cylindrical shaft (1) and securely fixed to the cylindrical shaft (1) in terms of rotation and displacement. The hollow, cylindrical cam (2) is provided with a foot strip (2.2, 2.3) that borders the cylindrical shaft (1) on one side and is welded to the cylindrical shaft (1) along, and through, the foot strip (2.2, 2.3).

Abstract: An improved cam and follower arrangement suitable for actuating, for example, poppet valves of an internal combustion engine and method and apparatus for forming the cam surface. This permits the use of skewed valve axes without using multiple rocker arms for each valve. The shapes are chosen and formed to provide better contact area and permits the cams to be ground with conventional grinding methods and for multi-cylinder engines.

Abstract: The invention relates to a finished camshaft (10) with several cams (1), fixed to a shaft (9), by means of at least one welded joint (11) each, whereby the shaft is made from a first low-carbon steel and the cams comprise a hardened or hardenable rocker running surface (2) made from a high-carbon steel (3) and are made from at least two different materials with a second low-carbon steel, which may be efficiently welded to the steel of the shaft, provided in at least one of the regions (4) affected by the welding.

Abstract: A method for producing an assembled shaft, especially an assembled camshaft, whereby parts, especially cams, are placed on a shaft in predetermined axial and peripheral positions and joined by compression pressure in a friction-tight manner. The cams in the thrust direction have a lubrication groove which surrounds the inner bore thereof and which is essentially wedge-shaped with a linear or curved slope, running in the direction of the wall of the bore. When the cam is slid on the shaft into the predetermined axial position, a lubricant is introduced into the groove. This lubricant is pulled continuously groove into the inner bore of the cam during the push-on process to significantly reduce friction between the inner bore and the shaft.