# US 11,028,874 B2 · Ball joint > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,028,874 B2 - Document ID: US11028874B2 - Status: Granted - Kind: B2 - Application number: 16/077,836 - Filed: 2017-01-16 - Published: 2019-02-21 - Granted: 2021-06-08 - Earliest claimed: 2016-02-18 - Assignees: ZF Friedrichshafen AG; Honda Motor Co., Ltd. - Applicants: ZF Friedrichshafen AG; Honda Motor Co., Ltd. - Inventors: Bernd Grannemann; Lutz Pydde; Martin Rechtien; Jinghong Yu - Web page: https://patentgrep.com/patent/US11028874B2 ## CPC - F16C 11/0647: {Special features relating to adjustment for wear or play; Wear indicators} - F16C 2326/01: Parts of vehicles in general - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS ## Abstract A ball joint with variable friction resistance for a vehicle, the joint having a stud with a joint ball which is held in a housing so as to articulate relative thereto. The housing comprises movable and static housing parts that are movable relative to one another and engage on opposite sides of the ball. A transmission is moved by one housing part so as to exert a variable pressure on the ball. The transmission has axially aligned transmission elements, each of which has a helical ball track. The transmission elements axially rest against one another via balls that are guided between the ball tracks of the transmission elements. A first transmission element can move axially and contact the movable housing part. A second transmission element can rotate about the rotational axis which causes the first transmission element to move axially and exert an axial force on the movable housing part. ## Claims ### Claim 1 A ball joint with variable friction resistance, the ball joint comprising: a ball stud having a joint ball which is held in a joint housing in order to move relative thereto in an articulated manner, the joint housing comprising static and movable housing parts that can move relative to one another, and which engage on opposite sides of the ball join, a transmission by which at least the movable housing part is movable so as to exert a variable pressure on the joint ball, the transmission having first and second transmission elements on each of which a respective ball track, of helical shape relative to a rotational axis, is formed, the first and the second transmission elements resting against one another, in an axial direction which is coincident with the rotational axis, via at least one ball that is guided between the ball tracks of the first and the second transmission elements, and the first transmission element is mounted to move axially and can be brought into pressing contact with the movable housing part, the second transmission element being mounted so as to rotate about the rotational axis such that rotation of the second transmission element axially moves the first transmission element so as to exert an axial force on the movable housing part. ### Claim 2 (depends on 1) The ball joint according to claim 1, wherein the first and the second transmission elements are each at least partially in the form of a disk-shaped body and have an axial surface which is formed, in each case, as an all-round inclined plane, and the ball tracks being formed respectively in all-round inclined planes of the respective transmission elements. ### Claim 3 (depends on 1) The ball joint according to claim 1, wherein at least three balls are guided between the first and the second transmission elements. ### Claim 4 (depends on 1) The ball joint according to claim 1, wherein the second transmission element is rotatably driven from outside by an interlocking engagement means formed thereon. ### Claim 5 (depends on 1) The ball joint according to claim 1, wherein a ball cage is arranged between the first and the second transmission elements and serves to guide the at least one ball along the ball tracks. ### Claim 6 (depends on 5) The ball joint according to claim 5, wherein the ball cage is a substantially disk-shaped component. ### Claim 7 (depends on 5) The ball joint according to claim 5, wherein an axial surface of the ball cage has an external contour which substantially matches a respective opposite external contour of an adjacent one of the first and the second transmission elements. ### Claim 8 (depends on 5) The ball joint according to claim 5, wherein the ball cage has a number of holes which correspond to the number of balls and which at least partially hold the balls. ### Claim 9 (depends on 5) The ball joint according to claim 5, wherein the first and the second transmission elements, in an assembled condition, and also the ball cage are connected with one another by an interlock in such a manner that the interlock prevents a translational movement of the first and the second transmission elements and the ball cage in a plane perpendicular to the rotational axis, but are rotatable relative to one another about the rotational axis. ### Claim 10 (depends on 5) The ball joint according to claim 5, wherein a cylindrical section is formed, on the first transmission element, which extends through a cylindrical aperture in the ball cage and into a cylindrical recess in the second transmission element. ### Claim 11 (depends on 5) The ball joint according to claim 5, wherein a stop is formed, on the first and the second transmission elements, which corresponds with a respective stop formed on the ball cage in order to define an initial position of the transmission. ### Claim 12 (depends on 1) The ball joint according to claim 1, wherein an anti-rotation lock is associated with the first transmission element which, while ensuring axial mobility, prevents the first transmission element from rotating about the rotational axis. ### Claim 13 (depends on 1) The ball joint according to claim 1, wherein a spring unit is associated with the transmission by which the first and the second transmission elements are prestressed axially against one another. ### Claim 14 (depends on 1) The ball joint according to claim 1, wherein a device by which a set rotational angle of the second transmission element is assigned to an axial force exerted on the movable housing part and can be stored. ### Claim 15 (depends on 14) The ball joint according to claim 14, wherein the device is operable on a basis of a stored relationship, between the rotational angle and the axial force, in order to specify a rotational angle required for producing a desired axial force. ### Claim 16 A transmission for a ball joint, having a ball stud having a joint ball, which is held in a joint housing in order to move relative thereto in an articulated manner, the joint housing comprising static and movable housing parts that can move relative to one another, and which engage on opposite sides of the ball joint, at least one of the movable housing parts being movable by the transmission so as to exert a variable pressure on the joint ball, the transmission having first and second transmission elements, and a respective ball track of helical shape, relative to a rotational axis, being formed on each of the first and the second transmission elements, the first and the second transmission elements resting against one another in an axial direction which is coincident with the rotational axis via at least one ball that is guided between the ball tracks of the first and the second transmission elements, and the first transmission element being mounted to move axially and can be brought into pressing contact with the movable housing part, the second transmission element being mounted so as to rotate about the rotational axis, such that rotation of the second transmission element axially moves the first transmission element so as to exert an axial force on the movable housing part, and the first transmission element being mounted so that the first transmission element can move axially whereas the second transmission element being mounted so that the second transmission element can rotate about the rotational axis in such a manner that, by rotating the second transmission element, the first transmission element being axially displaced. ### Claim 17 A ball joint with variable friction resistance for a vehicle, the ball joint comprising: a ball stud having a joint ball, the joint ball being received within a joint housing which defines a central axis, the ball stud and the joint ball being rotatable and pivotable relative to the joint housing, the joint housing having a static housing part and a movable housing part, the joint ball being received between the static housing part and the movable housing part such that movement of the movable housing part, along the central axis toward the static housing part, increasing a pressure placed on the joint ball by the joint housing, and movement of the movable housing part along the central axis, away from the static housing part, reduces the pressure placed on the joint ball by the joint housing; a transmission having first and second transmission elements, each of the first and the second transmission elements having a surface formed as a helical plane, the first and second transmission elements being coaxially aligned along the central axis such that a surface of the first transmission part and a surface of the second transmission part face each other, and the surfaces of the first and the second transmission elements each have a respective ball track that is helical in shape relative to the central axis; at least three balls being located axially between the first and the second transmission elements, each of the at least three balls being received by the ball tracks of the first and the second transmission elements such that the first and the second transmission elements axially contact each other via the at least three balls; and the first transmission element being axially movable to contact the movable housing part and the second transmission element being rotatable about the central axis so that movement of the at least three balls, within the ball tracks of the first and the second transmission elements, due to rotation of the second transmission element biases the first transmission element, via the at least three balls, to exert an axial force on the movable housing part and increase the pressure on the joint ball.