초록 ▼

An electromagnet (1), particularly a proportional magnet for operating a hydraulic valve, said electromagnet (1) comprising at least one coil winding (3) carried by a hollow cylindrical coil spool (2) which is circumferentially surrounded by a hollow cylindrical magnet housing (4) and limited at eac

An electromagnet (1), particularly a proportional magnet for operating a hydraulic valve, said electromagnet (1) comprising at least one coil winding (3) carried by a hollow cylindrical coil spool (2) which is circumferentially surrounded by a hollow cylindrical magnet housing (4) and limited at each end by a pole shoe (5, 6), said electromagnet (1) further comprising an axially moveable cylindrical armature (8) which is arranged in a hollow cylinder of the coil spool (2) that is configured as an armature space (7), the armature (8) being mounted for low friction in rotary, longitudinally moveable axial guides, and electromagnetically produced axial movements of the armature (8) can be transmitted to a hydraulic valve piston via a push rod (10) which is connected to the armature (8) to form an axial extension thereof. According to the invention, the rotary, longitudinally moveable axial guides of the armature (8) comprise at least one bushing-less linear ball bearing having a number of circumferentially spaced balls while being configured at the same time as an anti-stick means of the armature. The outer peripheral surface (9) of the armature (8) and/or the outer peripheral surface (11) of the push rod (10) is configured as an inner running track for the balls, and the inner peripheral surface of one or more components which limit the armature space (7) of the coil spool (2) forms an outer running track for the balls.

대표청구항 ▼

[ What is claimed is:] [1.]1. An electromagnet for operating a hydraulic valve which hydraulic valve is installed within a hydraulic system of a device for varying valve timing in an internal combustion engine, said electromagnet comprising: at least one coil winding carried by a hollow cylindrical

[ What is claimed is:] [1.]1. An electromagnet for operating a hydraulic valve which hydraulic valve is installed within a hydraulic system of a device for varying valve timing in an internal combustion engine, said electromagnet comprising: at least one coil winding carried by a hollow cylindrical coil spool, which coil spool is circumferentially surrounded by a hollow cylindrical magnet housing and a pole shoe is mounted adjacent each end of the coil spool, said electromagnet further comprising an axially moveable cylindrical armature which is disposed in a hollow cylinder of the coil spool which hollow cylinder defines a reception for an armature, said armature being mounted in low friction rotary, longitudinally moveable axial guides, and electromagnetically produced axial movements of the armature are transmitted to a hydraulic valve piston against a force of a spring via a push rod which is connected to the armature to form an axial extension thereof, wherein the rotary, longitudinally moveable axial guides of the armature comprise at least one bushing-less linear ball cage having a number of circumferentially spaced balls, said cage also serving as an anti-stick means of the armature, an outer peripheral surface of the armature and/or an outer peripheral surface of the push rod defines an inner running track for the balls, and an inner peripheral surface of the pole shoes or an inner peripheral surface of a pressure pipe lining the reception of the armature define an outer running track for the balls.