An adjustable stroke mechanism for a random orbital machine including a housing having a wall enclosing a cavity, an adjuster ring surrounding the housing and having a first set of gear teeth along a first portion of an inner surface, and a second set of gear teeth along a second portion of the inner surface, a counterweight having gear teeth on an exterior surface disposed within the housing, and a bearing carriage having gear teeth disposed within the housing. At least one counterweight gear that meshes with the gear teeth of the counterweight and the first set of gear teeth of the adjuster ring, and at least one bearing carriage gear that meshes with the gear teeth of the bearing carriage and the second set of gear teeth of the adjuster ring, so that movement of the adjuster ring causes movement of both the counterweight and the bearing carriage.

A plurality of balls inserted in the gap space between an outer ring raceway surface and an inner ring raceway surface are arranged at equally spaced intervals in a circumferential direction. The procedure of this ball arranging method for a ball bearing includes a ball holding step of holding any ball in the gap space by a ball holding mechanism provided at a tip of a robot arm and a ball moving step of moving the ball held by the ball holding mechanism along a pitch circle, and these steps are repeatedly performed for the plurality of balls based on a control program. Accordingly, the plurality of balls are arranged at equally spaced intervals on the pitch circle.

Provided is a hub unit bearing wherein a cover can be firmly fitted with an outer ring member, and it is difficult for foreign matter to enter inside through a water drainage hole formed in the cover. The cover that covers the inside end section in the axial direction of the hub unit bearing includes a disk section, a small-diameter cylindrical section bent in the axial direction from the outer perimeter edge section of the disk section and a large-diameter cylindrical section. A cut and raised section that is cut and raised toward the inside in the radial direction is formed in the small-diameter cylindrical section, and a water drainage hole that passes through from inside to outside the cover is provided in the portion that is cut and separated from the small-diameter cylindrical section.

Provided is a hub unit bearing wherein a cover can be firmly fitted with an outer ring member, and it is difficult for foreign matter to enter inside through a water drainage hole formed in the cover. The cover that covers the inside end section in the axial direction of the hub unit bearing includes a disk section, a small-diameter cylindrical section bent in the axial direction from the outer perimeter edge section of the disk section and a large-diameter cylindrical section. A cut and raised section that is cut and raised toward the inside in the radial direction is formed in the small-diameter cylindrical section, and a water drainage hole that passes through from inside to outside the cover is provided in the portion that is cut and separated from the small-diameter cylindrical section.

A compact bearing unit (1) for a double disc coulter (2) with ball bearing (23) with an inner ring (3), outer ring (5) with flange facing and a protective cap (7) has a multi-stage sealing system. A first seal (11) is provided between the inner ring 3 and an internal ring race (17) of the outer ring (5). At least one additional seal (14) is arranged between the protective cap (7) and a ring race (13, 17) of the outer ring (5), whereby said seal does not make any additional installation space necessary in the axial direction of the bearing unit (1).

A compact bearing unit (1) for a double disc coulter (2) with ball bearing (23) with an inner ring (3), outer ring (5) with flange facing and a protective cap (7) has a multi-stage sealing system. A first seal (11) is provided between the inner ring 3 and an internal ring race (17) of the outer ring (5). At least one additional seal (14) is arranged between the protective cap (7) and a ring race (13, 17) of the outer ring (5), whereby said seal does not make any additional installation space necessary in the axial direction of the bearing unit (1).

The invention relates to a bearing arrangement for a drilling head, through which flushing liquid flows, of a deep drilling device, having multiple radially outer and radially inner bearing rings, wherein the radially outer bearing rings are arranged coaxially over the radially inner bearing rings, wherein, radially between the bearing rings, there are arranged balls which roll in raceways of the bearing rings, and wherein the raceways are delimited axially on both sides by shoulders with mutually opposite shoulder surfaces which run parallel to a bearing longitudinal axis. In order for a bearing arrangement of this type, which, as per the prior art, is adjoined in an axial direction by at least one plain bearing, to be designed to be of short axial extent and in order to simplify the construction, the internal diameter (Di) of the shoulder surfaces of the radially outer bearing rings and the external diameter (Da) of the shoulder surfaces of the radially inner bearing rings are dimensioned such that said shoulder surfaces perform the function of parallel radial plain bearings with a radial clearance (S).

The invention relates to a bearing arrangement for a drilling head, through which flushing liquid flows, of a deep drilling device, having multiple radially outer and radially inner bearing rings, wherein the radially outer bearing rings are arranged coaxially over the radially inner bearing rings, wherein, radially between the bearing rings, there are arranged balls which roll in raceways of the bearing rings, and wherein the raceways are delimited axially on both sides by shoulders with mutually opposite shoulder surfaces which run parallel to a bearing longitudinal axis. In order for a bearing arrangement of this type, which, as per the prior art, is adjoined in an axial direction by at least one plain bearing, to be designed to be of short axial extent and in order to simplify the construction, the internal diameter (Di) of the shoulder surfaces of the radially outer bearing rings and the external diameter (Da) of the shoulder surfaces of the radially inner bearing rings are dimensioned such that said shoulder surfaces perform the function of parallel radial plain bearings with a radial clearance (S).

A strain wave gear has a wave generator rotatably mounted in a radially flexible sleeve having external toothing, a first rigid hollow wheel with internal toothing meshing with the external toothing of the radially flexible sleeve, and a second rigid hollow wheel with internal toothing meshing with the external toothing of the radially flexible sleeve. The wave generator is mounted by exactly one radially flexible roller bearing so as to be rotatable relative to the radially flexible sleeve. The roller bearing has a first rolling-element row, having first rolling elements, and at least one second rolling-element row, having second rolling elements, that is axially offset from the first rolling-element row. The roller bearing has an external ring with which the first and second rolling elements are in direct contact, and/or an internal ring with which the first and second rolling elements are in direct contact.

A strain wave gear has a wave generator rotatably mounted in a radially flexible sleeve having external toothing, a first rigid hollow wheel with internal toothing meshing with the external toothing of the radially flexible sleeve, and a second rigid hollow wheel with internal toothing meshing with the external toothing of the radially flexible sleeve. The wave generator is mounted by exactly one radially flexible roller bearing so as to be rotatable relative to the radially flexible sleeve. The roller bearing has a first rolling-element row, having first rolling elements, and at least one second rolling-element row, having second rolling elements, that is axially offset from the first rolling-element row. The roller bearing has an external ring with which the first and second rolling elements are in direct contact, and/or an internal ring with which the first and second rolling elements are in direct contact.