Bearing bush and production method for a bearing bush

Abstract

A bearing bush and a method for producing a bearing bush are provided. The bearing bush includes a core element, an elastomer element, a cage element and a sleeve element. The cage element is at least partially embedded in the elastomer element. The elastomer element elastically connects the cage element and the core element to each other. The core element, the cage element and the elastomer element form a pre-assembly element. One of the sleeve element and the cage element includes a protrusion. The other of the sleeve element and the cage element includes a groove, which is engageable with the protrusion, in an assembled state of the bearing bush. The pre-assembly element is fixed in the sleeve element. The protrusion and the groove form a two-point contact in a cross-section.

Claims

1. A bearing bush, comprising: a core element; an elastomer element; a cage element; and a sleeve element, wherein the cage element is at least partially embedded in the elastomer element, the elastomer element elastically connects the cage element and the core element to each other, and the core element, the cage element and the elastomer element form a pre-assembly element; one of the sleeve element and the cage element comprises a protrusion, the other of the sleeve element and the cage element comprises a groove, which is engageable with the protrusion, in an assembled state of the bearing bush, the pre-assembly element is fixed in the sleeve element, and the protrusion and the groove form a two-point contact in a cross-section.

2. The bearing bush according to claim 1, wherein the protrusion substantially has a shape of a circular segment with a first radius, and the groove substantially has a shape of a circular segment with a second radius, wherein the first radius is greater than the second radius.

3. The bearing bush according to claim 2, wherein a ratio of the first radius to the second radius is in the range of more than about 1.0 to about 1.4.

4. The bearing bush according to claim 3, wherein a ratio of the first radius to the second radius is in the range of more than about 1.0 to about 1.1.

5. The bearing bush according to claim 1, wherein the two-point contact is formed between the sleeve element and the cage element, and the cage element is exposed in the region of the two-point contact.

6. The bearing bush according to claim 1, wherein at least one of the sleeve element and the cage element comprises a readily elastically deformable material.

7. The bearing bush according to claim 6, wherein the readily elastically deformable material is plastic or fiber-reinforced plastic.

8. The bearing bush according to claim 1, wherein the protrusion is provided at an axial end of the element comprising the protrusion, and/or the groove is provided at an axial end of the element comprising the groove.

9. The bearing bush according to claim 1, wherein the bearing bush is a hydraulic bearing bush, wherein the elastomer element comprises at least one chamber for a damping fluid, wherein when the elastomer element comprises a plurality of chambers, the plurality of chambers is connected by at least one channel, provided by the elastomer element, and the elastomer element comprises a sealing lip, which is provided radially between the sleeve element and the cage element.

10. The bearing bush according to claim 9, wherein the protrusion and the groove form a sealing function for the damping fluid.

11. A production method of a bearing bush, comprising: providing a core element; providing a cage element; elastically connecting the core element and the cage element by an elastomer element, wherein the core element, the cage element and the elastomer element form a pre-assembly element; providing a sleeve element, wherein one of the sleeve element and the cage element comprises a protrusion, and the other of the sleeve element and the cage element comprises a groove, which is engageable with the protrusion; and fixing the pre-assembly element in the sleeve element such that, in an assembled state of the bearing bush, the protrusion and the groove form a two-point contact in a cross-section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective exploded view of a bearing bush or hydraulic bearing bush.

(2) FIG. 2 is a sectional diagram of a bearing bush or hydraulic bearing bush from FIG. 1 in the assembled state.

(3) FIG. 3a is an enlargement of a region of a bearing bush or hydraulic bearing bush in an incompletely assembled state.

(4) FIG. 3b is an enlargement of a region of a bearing bush or hydraulic bearing bush according to FIG. 3a in the assembled state.

(5) FIG. 4 is a sectional diagram of a further bearing bush.

(6) FIG. 5a is a front view of a further bearing bush.

(7) FIG. 5b is a sectional diagram of a further bearing bush.

(8) FIG. 6 is an enlargement of a region of the sectional diagram according to FIG. 5b.

(9) FIG. 7a is a part of the sleeve element according to the enlargement from FIG. 6.

(10) FIG. 7b is a part of the cage element according to the enlargement from FIG. 6.

(11) FIG. 8 is a flow diagram for the production or assembly of a bearing bush.

(12) FIGS. 9a-9i are examples of shapes or geometries for protrusion and groove for forming a two-point contact.

DESCRIPTION OF EMBODIMENTS

(13) FIG. 1 is a perspective exploded view of a bearing bush 10, which is in the form of a hydraulic bearing bush in the present case. The bearing bush 10 here comprises a stop 22, a core 20, an elastomer element 30, a cage element 40 and a sleeve element 50. An axial direction m here corresponds substantially to the axis of the bearing bush 10. A radial direction r is perpendicular to the axial direction m and corresponds to a substantially radial direction of the bearing bush 10.

(14) The elastomer element 30 is configured to connect the core element 20 and the cage element 40 elastically. The core element 20, the elastomer element 30 and the cage element 40 here form a pre-assembly element, which is pre-assembled or pre-manufactured in a step preceding the assembly of the bearing bush. The preassembly or pre-manufacturing step of the pre-assembly element that comprises the core element 20, the elastomer element 30 and the cage element 40 can comprise e.g. vulcanization.

(15) In a further step, the pre-assembly element comprising the core element 20, the elastomer element 30 and the cage element 40 is assembled in the sleeve element 50. The assembly step for assembling the pre-assembly element in the sleeve element 50 can comprise e.g. pressing in. The assembly of the pre-assembly element into the sleeve element here can be performed in the axial direction m.

(16) As also shown in FIG. 1, the elastomer element 30 can comprise at least one chamber or fluid chamber 32, which is configured to accommodate a damping fluid. In the case of a plurality of chambers or fluid chambers 32, these fluid chambers 32 can be in fluid communication with each other through one or more fluid channels. However, fluid channels are not shown in FIG. 1. With the aid of the at least one fluid chamber 32, which the elastomer element 30 comprises, the bearing bush 10 can act as a hydraulic bearing bush.

(17) The hydraulic bearing bush 10, compared with a non-hydraulic bearing bush, can exhibit a load-specific and thus advantageous damping in use or under load, but generally requires a seal. In FIG. 1, a sealing lip 36 is shown as a possible seal for the bearing bush 10. This sealing lip 36 can be configured in this case to be arranged radially between the cage element 40 and the sleeve element 50 in the assembled state of the bearing bush, thereby allowing the prevention of a possible leakage of a damping fluid between the cage element 40 or the pre-assembly element and the sleeve element 50.

(18) It is also possible for an additional, or even an only, sealing function between the cage element 40 and the sleeve element 50 to be provided by a two-point contact between the sleeve element 50 and the cage element 40 or between the sleeve element 50 and the pre-assembly element comprising the cage element 40. A secure sealing of a hydraulic bearing bush 10 can be ensured thereby. The two-point contact between the sleeve element 50 and the cage element 40 or between the sleeve element 50 and the pre-assembly element comprising the cage element 40 is described more precisely with the aid of the further figures.

(19) FIG. 2 is a sectional diagram of a bearing bush 10 according to FIG. 1, but in the assembled state. The sectional diagram according to FIG. 2 here is a cross-section along the axial direction m or along the axis of the bearing bush 10. Furthermore, the section plane of the sectional diagram according to FIG. 2 is rotated in a peripheral direction relative to a possible opening of the elastomer element 30, which is shown in FIG. 1 to illustrate a possible fluid chamber 32.

(20) As illustrated in FIG. 2, the cage element 40 is at least partially embedded in the elastomer element 30 such that the elastomer element 30 is arranged both radially inside the cage element 40 in part and radially outside the cage element 40 in part.

(21) Furthermore, FIG. 2 shows by way of example that a protrusion 60 can be arranged at an axial end of the sleeve element 50 and a groove 70 can be arranged at an axial end of the cage element 70. As already mentioned, in further embodiments by way of example the protrusion 60 can also be arranged on the cage element 40, at an axial end of the cage element 40, and the groove 70 can be arranged on the sleeve element 50, at an axial end of the sleeve element 50.

(22) Moreover, in further embodiments further protrusions 60 and further grooves 70 can be formed on the cage element 40 and the sleeve element 50. Preferably, the number of protrusions 60 corresponds to the number of grooves 70. Further preferably, the protrusions 60 are only arranged on one of the cage element 40 and the sleeve element 50, and accordingly the grooves 70 are preferably only arranged on the other of the cage element 40 and the sleeve element 50.

(23) FIG. 3a is an enlargement of a region of a bearing bush 10 in a cross-section along the axial direction m or along the axis of the bearing bush, in the incompletely assembled state. In this case the pre-assembly element is or the elements comprised by the pre-assembly element are already arranged at least regionally in the sleeve element 50 by an assembly in the axial direction m according to FIG. 1. As illustrated in FIG. 3a, there is still a distance between protrusion 60 and groove 70 in the axial direction m, such that the bearing bush 10 is not yet in the completely assembled state.

(24) As further illustrated by FIG. 3a, the protrusion 60 and the groove 70 can be arranged at an axial end of the sleeve element 50 and of the cage element 40, such that only a small axial region between the sleeve element 50 and the cage element 40 has a mutual radial overlap. Thus, when the pre-assembly element is being assembled in the sleeve element 50, advantageously, only low assembly forces or press-in forces are necessary for an assembly into the assembled state, as shown in FIG. 3a. Furthermore, an elevated assembly force or elevated press-in force is only necessary for a small axial region between the sleeve element 50 and the cage element 40 owing to the fact that the sleeve element 50 and the cage element 40 overlap radially.

(25) FIG. 3b is an enlargement of a region of a bearing bush 10 according to FIG. 3a, likewise in a cross-section along the axial direction m or the axis of the bearing bush 10 in the assembled state. In the assembled state, as shown by FIG. 3b, the protrusion 60 is arranged at least in part in the groove 70.

(26) FIG. 4 is a sectional diagram of a further bearing bush 10. The sleeve element 50 here is shown as a contoured element having various attachment possibilities or attachment points for fixing the sleeve element 50 in or on a component provided for the purpose. Furthermore, FIG. 4 shows an exemplary embodiment, wherein the sleeve element 50 has a protrusion 60 and the cage element 40 has a groove.

(27) Furthermore, FIG. 4 shows that, in addition to a groove 70, a cage element 40 can have an axial stop portion, which can be in contact with a complementary stop portion of the sleeve element 50.

(28) FIG. 5a is a front view of a further bearing bush 10. Furthermore, a section line A-A is shown in FIG. 5a, which runs in the radial direction of the bearing bush 10, providing a sectional view as shown in FIG. 5b. The sectional view according to FIG. 5b thus spans a two-dimensional illustration along a radial direction r and along an axial direction m or along an axis of the bearing bush 10.

(29) FIG. 5b is a sectional diagram of a further bearing bush 10, as obtained e.g. with the aid of the section line A-A through the bearing bush 10 according to FIG. 5a. As can be seen in the sectional diagram in FIG. 5b, the bearing bush 10 shown by way of example is formed only with a protrusion 60 and a groove 70 for fixing the pre-assembly element or the cage element 40 comprised by the pre-assembly element in the sleeve element 50.

(30) Furthermore, FIG. 5b shows an enlarged region B, which comprises the protrusion 60 and the groove 70, for further explanation of protrusion 60 and groove 70 with the aid of FIGS. 6, 7a and 7b.

(31) FIG. 6 is an enlargement of a region of the sectional diagram according to FIG. 5b and as indicated by the letter B. As shown by FIG. 6 in a cross-section running along the axial direction m according to FIG. 1, by way of example the sleeve element 50 comprises the protrusion 60 and the cage element 40 comprises the groove 70. The protrusion 60 has a shape of a circular segment with a first radius R1 and the groove 70 has a shape of a circular segment with a second radius R2, the first radius R1 being greater than the second radius R2. According to FIG. 6 the protrusion 60 has a shape of a circular segment that represents less than half of a circle. Furthermore, according to FIG. 6, the groove 70 has a shape that represents less than half of a circle as a hollow space or hollow shape.

(32) Furthermore, FIG. 6 shows the assembled state of a bearing bush 10, wherein the protrusion 60 is arranged at least in part in the groove 70.

(33) As a result of the geometric shapes of the protrusion 60 and the groove 70, each substantially as a circular segment with the first radius R1 of the circular segment of the protrusion being greater than the second radius R2 of the circular segment of the groove, a two-point contact between protrusion 60 and groove 70 is obtained automatically or by itself as a function of the precise shapes or geometries of the protrusion 60 and the groove 70. By means of the two-point contact between protrusion 60 and groove 70, the cage element 40 or the pre-assembly element comprising the cage element 40 is fixed in the sleeve element 50. Furthermore, it is made clear by the two-point contact that forms between protrusion 60 and groove 70 that the vertices of the geometries or shapes of the protrusion 60 and the groove 70 do not touch.

(34) As illustrated by FIG. 6, the radii R1 and R2 of the circular segments of the protrusion 60 and the groove 70 can each vary at will, with the two-point contact always forming or forming automatically by itself provided that the radius R1 is greater than the radius R2. This gives rise to the possibility of selecting the manufacturing tolerances for the manufacture or production of the cage element 40 and the sleeve element 50 such that they are sufficiently large, whereby the manufacture or production of the cage element 40 and the sleeve element 50 can be simplified and carried out cost-effectively. At the same time, an axial play between the cage element 40 and the sleeve element 50 is prevented by the fact that a two-point contact is formed between protrusion 60 and groove 70, as shown in FIG. 6.

(35) Furthermore in FIG. 6, a radial projection 76 on which the groove 70 is arranged, a radial extension 72 of the groove 70 and a radial extension 62 of the protrusion 60 are also illustrated. As shown in FIG. 6 by way of example, the element comprising groove 70 can be configured with a radial projection 76, in which case the groove 70 is formed inside the region comprising the radial projection 76 opposite the element comprising the further groove 70. In FIG. 6, where by way of example the groove 70 is arranged on the cage element 40, the radial projection 76 extends towards the sleeve element 50.

(36) The radial extension 62 of the protrusion 60 is obtained starting from the region comprising protrusion 60 of the element comprising protrusion 60 in the radial direction r towards the vertex of the protrusion 60 or the part of the protrusion 60 mostly projecting in the radial direction r towards the element comprising groove 70.

(37) The radial extension 72 of the groove 70 is obtained starting from the region comprising groove 70 of the element comprising groove 70 in the radial direction r towards the vertex of the groove 70 or the part of the groove 70 mostly projecting in the radial direction r away from the element comprising protrusion 60.

(38) The radial projection 76, which is preferably greater than the radial extension 62 of the protrusion 60, makes it possible when assembling the pre-assembly element or the cage element 40 comprised by the pre-assembly element that the protrusion 60 is radially pressed only in a partial region of a width or a partial region of an axial extension of the radial projection 76. Thus the assembly or pressing in of the pre-assembly element or the cage element 40 comprised by the pre-assembly element into the sleeve element 50 is facilitated and possible damage to the protrusion 60, the element comprising the protrusion 60 or the element comprising the groove 70 when pressing the pre-assembly element into the sleeve element 50 is reduced or even avoided.

(39) The dimensions of the bearing bush 10 as well as the dimensions of the sleeve element 50 and the cage element 40, like the dimensions of the protrusion 60 and the groove 70, are not limited and can be freely selected according to the desired application or embodiment.

(40) Exemplary embodiments, such as for application in the automotive sector, can have e.g. a radial extension 62 of the protrusion 60 ranging from about 0.2 mm to about 1.0 mm, preferably ranging from about 0.4 mm to about 0.8 mm and preferably of about 0.6 mm, and a radial extension 72 of the groove 70 ranging from about 0.2 mm to about 1.0 mm, preferably ranging from about 0.4 mm to about 0.8 mm and preferably of about 0.6 mm, while an exemplary first radius R1 of a circular segment of the protrusion 60 is, by way of example, in the range of about 0.8 mm to about 1.8 mm, preferably in the range of about 1.0 mm to about 1.6 mm and preferably about 1.3 mm, and an exemplary second radius R2 of a circular segment of the groove 70 is, by way of example, in the range of about 0.75 mm to about 1.75 mm, preferably in the range of about 0.95 mm to about 1.55 mm and preferably about 1.25 mm.

(41) Furthermore, to ensure the two-point contact in exemplary embodiments, the ratio of the radius R1 of a circular segment of the protrusion 60 to the radius R2 of a circular segment of the groove 70 is in the range of more than about 1.0 to about 1.4, preferably in the range of more than about 1.0 to about 1.2 and preferably more than about 1.0 to about 1.1.

(42) By means of a radius ratio or ratio of the first radius R1 of a circular segment of the protrusion 60 to the second radius R2 of a circular segment of the groove 70 close to 1.0 or just over 1.0, an advantageous and adequate penetration depth of the protrusion 60 can be ensured for arrangement in the groove 70. An adequate penetration depth of the protrusion 60 in the groove 70 in turn allows a force transfer between the element comprising the protrusion and the element comprising the groove, even in the case of a deflection of one of the elements under load or in use.

(43) Furthermore, as a result of a low radial extension 62 compared to the first radius R1 of a circular segment of the protrusion 60, only a low deformation of the elements to be assembled together occurs during assembly or when the pre-assembly element or the cage element 40 comprised by the pre-assembly element is pressed into the sleeve element 50. The fact that the deformation of the elements to be assembled together, i.e., the cage element 40 and the sleeve element 50, is only low furthermore reduces the probability of damage during assembly of the elements to be assembled together, i.e., the cage element 40 and the sleeve element 50.

(44) FIG. 7a shows a part of the sleeve element 50 according to the enlargement region B from FIG. 6, while FIG. 7b shows a part of the cage element 40 according to the enlargement region B from FIG. 6. FIGS. 7a and 7b serve to illustrate the radial projection 76, the radial extension 62 of the protrusion 60 and the radial extension 72 of the groove 70. By way of example, and according to FIG. 6, the sleeve element 50 is configured to comprise the protrusion 60, with a circular segment of radius R1, and the cage element 40 is configured to comprise the groove 70, with a circular segment of radius R2.

(45) In further exemplary embodiments, the sleeve element 50 is configured to comprise the groove 70, with a circular segment of radius R2, and the cage element 40 is configured to comprise the protrusion 60, with a circular segment of radius R1. Furthermore, in further exemplary embodiments, the sleeve element 50 can comprise a radial projection 72, which facilitates assembly and requires lower assembly forces as well as causing less damage during assembly if groove 70 and/or protrusion 60 are not arranged at an axial end of the particular element comprising the groove 70 or protrusion 60.

(46) FIG. 8 is a flow diagram for the production or assembly of a bearing bush 10, comprising the following steps:

(47) Starting with S10: Providing a core element 20.

(48) S20: Providing a cage element 40.

(49) S30: Elastically connecting the core element 20 and the cage element 40 by an elastomer element 30 to form a pre-assembly element. For example, the step S30 can be achieved by vulcanization.

(50) S40: Providing a sleeve element 50.

(51) S50: Fixing the pre-assembly element in the sleeve element 50 to form a two-point contact between a protrusion 60 and a groove 70 in a cross-section along the axis of the bearing bush or the axial direction m, the protrusion 60 being provided by one of the sleeve element 50 and the cage element 40, and the groove 70 being provided by the other of the sleeve element 50 and the cage element 40.

(52) In other words, one of the sleeve element 50 and the cage element 40 comprises a groove 70 and the other of the sleeve element 50 and the cage element 40 comprises a protrusion 60. In preferred embodiments, the protrusion 60 is configured as a circular segment having a radius R1 which is greater than a radius R2 of a circular segment comprised by the groove 70 or comprised as a hollow shape by the groove 70.

(53) FIGS. 9a to 9i are examples of shapes for protrusion 60 and groove 70 for forming a two-point contact. Besides the illustrated shapes shown, further geometric shapes are possible for each of protrusion 60 and groove 70 and are combinable with each other, which can serve to form a two-point contact between protrusion and groove.

(54) The figures show the following:

(55) FIG. 9a: a protrusion 60 in the shape of a circular segment with a radius R1 that is greater than a radius R2, which describes the shape of a circular segment of a groove 70;

(56) FIG. 9b: a protrusion 60 in the shape of a double circular segment and a groove 70 in the shape of a single circular segment;

(57) FIG. 9c: a protrusion 60 in the shape of a polygon, such as a pentagon, and a groove 70 in the shape of a circular segment;

(58) FIG. 9d: a protrusion 60 in the shape of a rectangle and a groove 70 in the shape of a circular segment;

(59) FIG. 9e: a protrusion 60 in the shape of a triangle and a groove 70 in the shape of a circular segment;

(60) FIG. 9f: a protrusion 60 in the shape of a trapezium and a groove 70 in the shape of a circular segment;

(61) FIG. 9g: a protrusion 60 in the shape of a triangle and a groove 70 in the shape of a triangle, wherein both triangles are configured as equilateral triangles and preferably the base of the triangle of the protrusion is larger than the base of the triangle of the groove;

(62) FIG. 9h: a protrusion 60 in the shape of a circular segment and a groove 70 in the shape of a triangle; and

(63) FIG. 9i: a protrusion 60 in the shape of a trapezium and a groove 70 in the shape of a triangle.