The subject of this invention is a ball joint, especially in vehicle suspension components, including but not limited to suspension arm, stabilizer link or steering rod end.

Ball joints are well-known and widely used in the automotive industry. Ball joints get worn as a result of vehicle use and the resulting loose elements cause suspension knocking and reduced driving comfort. In extreme situations, a worn ball joint may cause, for example, detachment of the steering knuckle together with the wheel from the suspension arm.

From the US patent No. 3005647, a ball joint for use in independently suspended wheels of motor vehicle suspension systems, in which the ball joint works with two annular bearing rings, where the upper bearing ring made of metal alloys is pressed to the ball joint stud by means of a resilient ring, is known.

From the US patent No. 5655848, a ball joint for use in motor vehicle suspension systems using the lower bearing seat and an assembly, in which a rubber pressure ring is located between the upper cap and the pressure plate that provides an upper bearing seat, is known.

Description of the US patent No. 6010271 reveals the method of assembling a ball joint using two bearings, where the first one is made of polymeric material and pressed against the stud by means of a coil spring and the other one is made of metal. From the US patent No. 9010783, a ball joint, where a single bearing cup made of a thermoplastic material and permanently connected with the suspension arm body works with a ball stud, is known.

A ball joint, particularly a ball joint for use in motor vehicle suspension system elements, according to this invention, includes a plastic bearing cup and a metal ball stud, seated in the socket of the metal body of the joint of a motor vehicle suspension component. A resilient lock ring adheres to the bottom of the bearing cup surface separated with a metal washer, where the ring is pressed by a plug closing the joint socket.

It is preferred that the shape-defining part of the bearing cup is provided with notches along its longitudinal axis, allowing the bearing ring to move in the socket of the joint body as a result of the expansion of the resilient lock ring adhering to the metal washer placed in the ribbing of the bottom of the bearing cup.

The bearing of the ball joint is made of polyamide and it is connected in a dismountable way with the joint socket. Characteristic for the invention is the lack of permanent connection of the bearing with the joint socket of the element body in a motor vehicle suspension component. Circular notches of the body and the bearing cup allow increasing the tilt of the ball stud in both turns.

In order to ensure adequate lubrication during operation of the ball joint, the bottom surface of the bearing cup is provided with an opening and the plug includes a spherical indentation, where the free space between the spherical indentation and the opening of the bearing cup with the stud is filled with grease. An advantage of the invention is the fact that play between the stud and the bearing cup generated during intensive use of the ball joint is compensated with expansion of the pressed lock ring.

It is also advantageous that the design of the ball joint is simplified by using a specially shaped, single bearing cup and elimination of the metal pressure spring. One component of a motor vehicle suspension system (e.g. stabilizer link) can be provided with more ball joints and joint sockets.

The object of the invention has been presented on an exemplary drawing of a suspension arm, on which: fig. 1 is a top view of the suspension arm;

fig. 2 is a side view of the suspension;

fig. 3 presents a cross-section of a suspension arm joint in 2: 1 scale along line A- A fig- 2;

fig. 4 presents the first isometric projection of the polyamide spherical bearing cup of the joint with a visible split into sections; fig. 5 presents the second isometric projection of the polyamide spherical bearing cup of the joint with highlighted bearing cup bottom;

fig. 6 presents the second isometric projection of the polyamide spherical bearing of the joint with highlighted spherical shaped portion of the bearing cup;

fig. 7 presents a general assembly drawing of the ball joint (suspension arm body not seen) with an expanded lock ring, before press-fitting of the cap;

fig. 8 presents a general assembly drawing of the ball joint (suspension arm body not shown) with an engaged lock ring after press-fitting of the plug; fig. 9 presents the body of the suspension arm with a visible socket of the joint and spherical notches;

fig. 10 presents the body of the suspension arm with the bearing in the socket of the joint and visible spherical notches;

fig. 11 presents the body of the suspension arm with the ball joint and visible spherical notches.

In one embodiment of the invention, the suspension arm consists of a metal body (1) with one socket of the joint (2) and a ball joint consisting of a spherical bearing cup of the joint (3) made of a slippery plastic material - polyamide and a steel ball stud (4). The bearing cup consists of a spherical shaping portion (3 a), a cylindrical bushing portion (3b) and a profiled bottom (3 c). The profiled bottom (3 c) of the bearing cup (3) is provided with ribbing (3d) and an opening (3e). The bearing cup (3) is not permanently fixed to the body (1) of the suspension arm and thanks to the notches (3f) in the spherical portion (3 a) the bearing cup (3) can move in the socket of the joint (2). The resilient lock ring in the form of a rubber O- ring (5) is separated from the bearing (3) with a metal washer (6) placed on the ribbing (3d) of the profiled bottom (3c) of the bearing (3) and pressed with the metal plug (7). The plug (7) in the assembly process is locked on a press (press-fit) thanks to which the ball joint cannot be disassembled. In order to increase the tilt of the ball joint (4) in both turns, the body (1) and the spherical portion (3 a) of the bearing (3) are provided with spherical notches (8). At the same time, in order to ensure adequate lubrication during operation of the ball joint, the profiled bottom (3c) of the bearing ring (3) is provided with an opening (3e) and the plug (7) is provided with a spherical indentation (7a), where the free space (9) between the spherical indentation (7a) and the opening (3e) of the bearing cup (3) with the stud (4) is filled with solid grease. After pressing, the engaged resilient spring ring (5) as a result of internal pressing forces of the system is pressed against the bearing (3) all the time, eliminating ball joint play. As a result of intensive use of the suspension arm, when the polyamide bearing ring (3) is worn and generates play between the bearing and the ball stud (4), the resilient lock ring (5) presses in the ball joint socket (2) the spherical bearing cup (3) against the ball stud (4), eliminating the play.

Protection of the ball joint against adverse external conditions is provided with a rubber dust cover (10) connected with the body (1) by means of a pressure spring (11) and connected with the ball stud (4) by means of a pressure ring (12).

An advantage of the ball joint according to this solution is particularly ensuring that thanks to the use of a lock ring and the specific design of the bearing, automatic compensation of play generated in the joint as it wears down. In addition, the ball joint according to the invention is characterized by a simple design, which improves its durability and reduces the manufacturing and operating costs. What is more, the ball joint with a simple design shows reduced weight compared to solutions known earlier.