Provided is a bearing lubrication structure for a rotation unit having a bearing that is of a grease lubrication type in which the bearing is provided at both sides thereof with a seal structure, wherein the grease lubrication performance is improved. The bearing is provided on both sides thereof with fixed-side seal portions, and rotating side seal portions that are opposed thereto, respectively. The fixed-side seal portion is provided with a shield. The distance from the inner periphery of the shield to the axis of the rotary shaft varies depending on the location of a point on the inner periphery. The shield, which is one of the two shields, and the shield, which is the other one, are arranged so as not to have plane symmetry.

A plain bearing arrangement for a shaft loaded with a circumferential radial force, having a bearing ring arranged in a rotationally fixed manner in a housing component and having a first running surface formed on the inner circumference, and a second running surface formed on the outer circumference of the shaft or on the outer circumference of a sleeve arranged on the shaft, the second running surface being mounted in a sliding manner on the first running surface, wherein a device for axially feeding a lubricant to an end side of the shaft is provided, and at least one axially extending, radially open groove that is axially open in a direction of the end side of the shaft is formed in the second running surface.

A slewing bearing for vertical structural support, including a first bearing ring, a second bearing ring and at least one row of rolling elements arranged between the first and second bearing rings. The first or second bearing ring is provided with a gear for receiving the drive of an input torque, and the gear is provided axially thereunder with a lubricant collecting member for keeping the lubricant. A rotary support device is provided for supporting in a vertical structure. The device provides a first member that supports substantially in a vertical direction, a second member that is substantially supported by the first member in the vertical direction, and the slewing bearing acting as a rotary support between the first and second members. The first member is fixedly connected to the first bearing ring and the second member is fixedly connected to the second bearing ring.

Disclosed is a sealed bearing arrangement that provides at least a bearing with an outer ring and an inner ring, which are rotatable to each other and form a rolling chamber between each other, in which a set of rolling elements. A lubricant is encompassed in the rolling chamber and the rolling chamber is sealed off from an environment by at least one sealing element. The inner ring, the outer ring and/or the sealing element includes at least one opening for providing a fluid passage through the sealing element. The bearing is arranged in a housing that is adapted to seal off the bearing from an outside environment. A lubricant is encompassed inside the housing. The housing including the at least one opening for providing a fluid passage from the inside of the housing to the outside. The opening is fluid tightly connected to an oxygen removing element and/or to a gas tank, which provides an oxygen poor to free fluid flow to the rolling chamber.

To provide a grease composition that is capable of effectively preventing an early-flaking caused by hydrogen embrittlement, and a grease-sealed bearing in which the grease composition is sealed. A grease composition 7 contains a base oil, a thickener, and an additive. The additive contains sodium molybdate, and zinc alkyldithiophosphate having a 1-30 C primary alkyl group. The grease composition contains 0.1-5 mass % of the sodium molybdate relative to the whole of the grease composition. The grease composition contains 0.1-5 mass % of the zinc alkyldithiophosphate relative to the whole of the grease composition.

A rolling bearing having an outer ring, an inner ring, and at least one row of rolling elements disposed between two raceways of the outer and inner rings. Furthermore, the raceway of the outer ring and/or the raceway of the inner ring at least partially provide a coating based on chromium nitride, the rolling elements at least partially include a coating based on carbon.

A rolling bearing capable of achieving reduction in torque is provided. The rolling bearing includes an inner ring and an outer ring disposed coaxially with each other, a rolling element disposed between the inner ring and the outer ring, a seal member configured to cover an area between the inner ring and the outer ring from an outside in an axial direction, and filled grease disposed between the rolling element and the seal member. The filled grease includes a first ring-like part which extends to form a circumferential shape centering on a common axis of the inner ring and the outer ring, and which has contact with one of the inner ring and the outer ring, and a second ring-like part which extends to form a circumferential shape centering on the common axis, which is connected to the first ring-like part at an outer side in the axial direction, and which has contact with the seal member.

A rotary actuator where a thrust bearing ring is positioned at an inside of a tube assembly accommodating oil, thereby reducing abrasion and damage caused by rolling friction and improving rotary power of an axle load by increasing hydraulic pressure of a piston. The rotary actuator includes the tube assembly, a piston, an axle load assembly, and a thrust bearing ring. The tube assembly is provided with a tube spiral portion where a spiral is formed at an inner circumference surface, and is formed of a first passage where oil flows into and out and a second passage spaced apart from the first passage by a fixed distance.

Provided is a rolling bearing that can both ensure durability and reduce rotational resistance. The rolling bearing includes a seal member that is mounted on an outer ring and that covers a space between an inner ring and the outer ring from an outer side in an axial direction, and grease disposed between a rolling element and the seal member. The seal member includes an annular pedestal portion in contact with the outer ring from an outer side in the axial direction, an extending portion that extends outward in the axial direction from an inner peripheral edge of the pedestal portion, and a flat surface portion that extends along a radial direction from an end edge of the extending portion on an outer side in the axial direction toward the inner ring. The grease includes an outer ring contact portion in contact with an inner peripheral surface of the outer ring, and a seal member contact portion in contact with the flat surface portion on an outer side in the axial direction and an inner ring side with respect to the outer ring contact portion. An area of the seal member contact portion is larger than a contact area between the grease and the extending portion as well as the pedestal portion of the seal member.

A bearing system includes a bearing housing configured to house a bearing and enclosing a free volume for receiving a lubricant, a bearing, a pump configured to pump lubricant into the free volume, a shaft in an opening in the housing rotatably supported by the bearing, an exclusion seal between the shaft opening and the shaft that is repeatably and non-destructively shiftable from a sealing state in which it substantially prevents lubricant from leaving the free volume and a release state in which it allows lubricant to escape between the exclusion seal and the shaft. The exclusion seal is caused to shift by increasing and decreasing a pressure in the bearing housing, and the system includes a controller configured to repeatedly shift the exclusion seal by raising and lowering the pressure in the free volume to continuously maintain a lubricating film between the exclusion seal and the shaft.