BALL JOINT

Description

[0001] The invention relates to a joint ball for a ball joint of a ball joint shaft, wherein the joint ball has an outer spherical surface and a first groove and a second groove for receiving a separate joint hub each, and both grooves are set at an angle α to each other and are arranged at least partially circumferentially around the joint ball.

[0002] Ball joints with joint balls for a ball joint shaft are already known. Such ball joint shafts are used in a similar way to cardan shafts to couple non-aligned pins to transmit torque. To ensure trouble-free operation of the ball joints, manual or automatic external drop lubrication or constant lubrication with grease is necessary. Constant lubrication is achieved by a protective cover, such as a bellows, which surrounds the ball joint and is filled with grease once during production. With drop lubrication, short lubrication intervals are necessary; at least once a day during continuous operation. According to DE 228 747 A, a brake linkage with a ball joint is described as a connection between a lever and an arm. This ball joint, designed as a universal joint, has a ball with two vertically intersecting annular grooves.US 1 443 930 A1 describes a system in which, in addition to the joint ball, guides are provided that form a groove for the joint fork. The guides are mounted circumferentially on the joint ball. According to DE 1 206 669 B and EP 2 592 295 A1, joint balls are known that have grooves, with recesses provided on the groove base as a reservoir for lubricant.

[0003] The invention is based on the object of designing and arranging a ball joint in such a way that wear and, at the same time, lubrication intervals are reduced.

[0004] The object is achieved according to the invention in that a channel system with several channels for lubricant is arranged in the joint ball and the channel system connects the ball surface with the groove.

[0005] This allows lubricant in the form of grease to be applied directly and precisely from the outside of the ball joint to the sliding surfaces of the ball joint, reducing wear due to direct lubrication in the groove. This is especially true for relubrication at certain lubrication intervals, as this eliminates the need to disassemble the ball joint shaft and bellows.

[0006] Accordingly, lubrication can be achieved through the channels with grease without the need for a bellows. The bellows is constantly deformed as the ball joint shaft rotates, which is why cracks appear in the bellows after a certain period of operation. Without a bellows, this type of wear does not occur, which indirectly affects the service life of the ball joint. Furthermore, without a bellows, the absolute rotational diameter of the bent ball joint shaft in an angled position is reduced because the external dimensions are smaller due to the missing bellows. Compared to drip lubrication, grease lubrication also offers a type of constant lubrication, with maintenance intervals reduced by a factor of between five and twenty compared to drip lubrication. Depending on the application, the grease lubrication according to the invention only needs to be carried out every 20 days instead of daily.Drop-type lubrication also has the disadvantage that, due to the oil used as a lubricant, external dirt is transported into the bearing along with the oil. The solution according to the invention has the advantage that the grease can be introduced into the center of the ball joint through the channels, and by supplying or pressing new grease into the bearing, the old grease in the bearing, along with wear particles and contaminants, is forced out of the ball joint.

[0007] It can also be advantageous if the groove has a groove base and a channel of the channel system, designed as a connecting channel, opens at the groove base. This ensures that the grease supplied via the channels is guided directly to the sliding surface between the groove and the joint hub.

[0008] For easy lubrication, it can be advantageous to provide a grease nipple on the ball surface and a channel of the channel system designed as a feed channel connecting the connecting channel to the grease nipple. The grease nipple and the feed channel enable centralized grease lubrication. Keeping the number of channels as small as possible ensures minimal weakening of the joint ball, as this allows as much material as possible to remain on the joint ball.

[0009] It can also be advantageous if all channels are arranged radially to the ball surface and connected to each other at the ball center. This simplifies the production of the joint ball because the channels can be drilled or milled perpendicular to the ball surface. The connecting channel thus connects two positions on the groove base that are opposite each other with respect to the joint ball.

[0010] For universal use, it can advantageously be provided that the groove extends 360° around the joint ball. This allows the joint ball to rotate freely through 360° relative to the joint hub.

[0011] With regard to the accessibility of the ball joint's lubrication nipple, it may be particularly important for the present invention if the connecting channels are arranged in one plane and the supply channel is arranged parallel to the plane or at an angle δ greater than zero. A position of the lubrication nipple oriented toward the intersection of the two grooves may be advantageous for relubrication in installation situations where the ball joint is difficult to access.

[0012] Likewise, with regard to the accessibility of the grease nipple of the joint ball, it may be advantageous if the feed channel is set at an angle β other than 45° relative to the connecting channel.

[0013] With regard to the relative courses of the grooves and channels, it is intended that the angle α has a value of 90° (degrees) or between 45° (degrees) and 89° (degrees) and / or the angle β has a value of 45° (degrees) or between 20° (degrees) and 44° (degrees) and / or the angle δ has a value between 5° (degrees) and 35° (degrees).

[0014] To reduce lubrication intervals, it is advantageous to provide a recess in the groove base that runs at least partially parallel to the groove base around the joint ball and into which the connecting channel opens. This recess serves as a lubricant reservoir, which is automatically filled when new grease is added before the grease penetrates the remaining groove. Since the recess extends circumferentially along the groove base, better distribution of the lubricant along the groove is achieved by pressing the lubricant in.

[0015] To better orient the lubricant supply, the recess is offset circumferentially around the groove base relative to an opening of the connecting channel. For each joint hub, this offset is in opposite directions because the two joint hubs are positioned opposite each other with respect to the joint ball.

[0016] For better support, it may be advantageous if the groove base has two flat, parallel surfaces opposite the joint ball, designed for insertion into the joint hub. This allows the use of a joint hub whose forks enclose the joint ball at an angle of more than 180°.

[0017] As an alternative to the centrally located channels, a connecting channel of the channel system can be provided, opening onto a groove flank. Depending on the direction of rotation, the greatest friction occurs between a groove flank and the joint hub, making this geometry advantageous for supplying lubricant directly to the groove flank.

[0018] Further advantages and details of the invention are explained in the claims and the description and illustrated in the figures. They show: Figure 1 shows a top view of a ball joint with a joint ball and two joint hubs; Figure 2 shows a perspective view of the joint ball; Figure 3 shows a top view of the joint ball parallel to a groove according to Figure 1 without joint hubs; Figure 4 a sectional view AA of the joint ball according to Figure 3 ; Figure 5 a plan view of the joint ball parallel to two grooves; Figure 6 a sectional view BB of the joint ball according to Figure 5 ; Figure 7 a sectional view CC of the joint ball according to Figure 5 and Figure 8 a sectional view of the joint ball according to Figure 7 with a joint hub.

[0019] In Figure 1 A ball joint shaft 2 with a central ball joint 1 and two shafts 2.1 connected to the ball joint 1 are shown. The ball joint 1 consists of a joint ball 3 and two joint hubs 8, 9 engaging on the right and left into the joint ball 3. The joint hubs 8, 9 are formed at the ends with corresponding forks 8.1, 9.1, which are inserted into the grooves, which in Figure 8 is shown in more detail.

[0020] Figure 2shows a joint ball 3 according to the invention with its outer spherical surface 3.1. In the joint ball 3, a first groove 4 is provided, which completely surrounds the joint ball 3, and a second groove 5, which also completely surrounds the joint ball 3. The second groove 5 runs at right angles to the first groove 4. The respective groove 4, 5 forms parallel groove flanks 4a / b, 5a / b on both sides of the groove 4, 5, which are arranged at right angles to the spherical surface 3.1. As shown in the sectional view AA in Figure 4As shown more precisely, several channels 6a-6c are introduced into the joint ball 3. Each of the two connecting channels 6a, 6b runs diametrically in the radial direction through the joint ball 3 and through the center of the ball from one side of the ball to the other. The groove 4, 5 is thus connected to the groove base 4.1, 5.1 via the respective connecting channel 6a, 6b, since the connecting channel 6a, 6b opens at the groove base. The two connecting channels 6a, 6b run in a plane E at an angle α of 90° (degrees) to one another. Furthermore, a feed channel 6c is provided, which also runs at right angles to the spherical surface 3.1 in the radial direction up to the center of the ball. The feed channel 6c is thus connected to the two connecting channels 6a, 6b. On the input side, a grease nipple 10 is provided on the feed channel 6c, via which a pasty lubricant such as lubricating grease can be introduced into the two grooves via the feed channel 6c and the connecting channels 6a, 6b.The feed channel 6c is positioned at an angle β of 45° (degrees) to the connecting channels 6a, 6b. In the embodiment according to . Figure 4 The feed channel 6c lies in the plane E, which is spanned by the two connecting channels 6a, 6b. For this relative position, reference is made to the respective center axis of the channels 6a-6c.

[0021] In the embodiment according to Figure 3 , which shows the section AA, the feed channel 6c is set at an angle δ of approximately 40° (degrees) relative to the plane E. This allows advantageous accessibility to the lubrication nipple 10 in the installation situation of the ball joint shaft 2.

[0022] In the Figures 2 to 8In addition, recesses 7 can be seen at the groove base, which serve as a reservoir for lubricant. The recess 7 extends from the connecting channel 6a, 6b in both circumferential directions along the groove base and is thus supplied with lubricant via the connecting channel 6a, 6b. This distributes the lubricant circumferentially around the joint ball 3 at the groove base in both circumferential directions. Figure 5 shows a view of the two grooves 4, 5 crossing in one of two opposite crossing points K. In the groove 4, the two recesses 7 are arranged offset relative to an opening M of the connecting channel 6a, 6b in the direction of a surface 11a, which is also shown in Figure 6 In the groove 5, the offset is provided in the other direction towards the surface 11b, which is Figure 7 The respective recess 7 in the two grooves 4, 5 is as shown in Figure 8shown in more detail, arranged offset relative to the mouth M of the connecting channel 6a, 6b in a circumferential direction U shown by an arrow.

[0023] The Figure 8 The joint hub 9, shown in section, encloses the joint ball 3 by more than 180° (degrees). For this purpose, two forks 9.1 are provided, the ends of which have a distance Ag that is smaller than the diameter of the joint ball 3 at the groove base. So that the fork 9.1 can be placed onto the joint ball 3, two opposing surfaces 11a / b are provided in the respective groove 4, 5 at the intersection points K of the two grooves. The distance Ak between the two parallel surfaces 11a / b is a few hundredths of a millimeter smaller than the distance Ag between the forks 9.1. This allows the joint ball 3 to be inserted into the joint hub 9. The same design is provided for the joint hub 8 and the fork 8.1 (not shown).

Claims

1. A joint ball (3) for a ball joint (1) of a ball-jointed shaft (2), wherein the joint ball (3) has an outer ball surface (3.1), as well as a first groove (4) and a second groove (5) for respectively inserting a separate joint hub (8, 9), and wherein both grooves (4, 5) are angled relative to one another by an angle α and realized so as to at least partially extend around the joint ball (3), characterized in that a channel system (6) for lubricant with multiple channels (6a-6c) is provided in the joint ball (3), and in that the channel system (6) connects the ball surface (3.1) to the groove (4, 5).

2. The joint ball (3) according to claim 1, characterized in that the groove (4, 5) has a groove base (4.1, 5.1), and in that a channel of the channel system (6), which is realized in the form of a connecting channel (6a, 6b), opens out into the groove base (4.1, 5.1).

3. The joint ball (3) according to one of claims 1 or 2, characterized in that a lubricating nipple (10) is provided on the ball surface (3.1), and in that a channel of the channel system (6), which is realized in the form of a feed channel (6c), connects the connecting channel (6a, 6b) to the lubricating nipple (10).

4. The joint ball (3) according to one of the preceding claims, characterized in that all channels (6a-6c) are arranged in the radial direction to the ball surface (3.1) and connected to one another in the center of the ball.

5. The joint ball (3) according to one of the preceding claims, characterized in that the groove (4, 5) extends around the joint ball (3) over an angle of 360° (degrees).

6. The joint ball (3) according to one of claims 2 to 5, characterized in that the connecting channels (6a, 6b) are arranged in a plane (E), and in that the feed channel (6c) is arranged parallel to the plane (E) or angled relative to said plane by an angle δ.

7. The joint ball (3) according to one of claims 3 to 6, characterized in that the feed channel (6c) is angled relative to the connecting channel (6a, 6b) by an angle β.

8. The joint ball (3) according to one of the preceding claims, characterized in that the angle α has a value of 90° (degrees) or between 45° (degrees) and 89° (degrees) and / or the angle β has a value of 45° (degrees) or between 20° (degrees) and 44° (degrees) and / or the angle δ has a value between 5° (degrees) and 35° (degrees).

9. The joint ball (3) according to one of claims 2 to 8, characterized in that a depression (7) is provided in the groove base (4.1, 5.1), wherein said depression extends around the joint ball (3) at least partially parallel to the groove base (4.1, 5.1) and the connecting channel (6a, 6b) opens out into the depression.

10. The joint ball (3) according to claim 9, characterized in that the depression (7) is arranged offset in relation to a mouth (M) of the connecting channel (6a, 6b) on the groove base (4.1, 5.1) in the circumferential direction (U) around the groove base (4.1, 5.1).

11. The joint ball (3) according to one of claims 2 to 10, characterized in that the groove base (4.1, 5.1) has two planar surfaces (11a, 11b), which lie opposite of one another with respect to the joint ball (3) and are arranged parallel to one another, wherein said planar surfaces are provided for the insertion into the joint hub (8, 9) .

12. A ball joint (1) and / or a ball-jointed shaft (2) with at least one joint ball (3) according to one of the preceding claims.

13. Use of a joint ball (3) according to one of claims 1 to 11 for lubricating a ball joint (1) of a ball-jointed shaft (2).

14. A system consisting of a joint ball (3) according to one of claims 1 to 11 or a ball joint (1) or a ball-jointed shaft (2) according to claim 12 and a drive unit for an assembly.

15. A method for lubricating a ball joint (1) of a ball-jointed shaft (2) with a joint ball (3), characterized in that channels (6a-6c) are provided in the joint ball (3) in the radial direction toward the center of the joint ball (3), and in that lubricant is conveyed through the joint ball (3) from the ball surface (3.1) into the grooves (4, 5) of the joint ball (3) via the channels (6a-6c), wherein a joint hub (8, 9) can be arranged in the grooves of the joint ball.