SHAFT SEAL WITH LIPS, GEARBOX WITH SHAFT SEAL AND METHOD FOR LUBRICING A SHAFT SEAL

Description

[0001] The invention relates a system comprising a shaft seal and a Arrangement for applying lubricant to a lip-enclosing shaft seal ring with a mandrel, a gearbox with shaft seal and a method for lubricating a shaft seal.

[0002] It is generally known that a shaft seal is used to seal an oil-filled interior area of ​​a gearbox.

[0003] From the DE 10 2009 050 215 A1 A non-grinding sealing ring is known.

[0004] From the WO 2009 / 103314 A1 A sealing arrangement is known.

[0005] From the EP 3 546 776 A1 A shaft seal is known.

[0006] From the JP 2015 124785 A A lubrication device for a shaft seal is known.

[0007] From the CN 106 989 178 A A shaft seal is known.

[0008] From the US 2015 / 086448 A1 A measuring device for liquids is known.

[0009] Out of the JP H05 293513 A The most obvious state of the art is an arrangement known for lubricant application, according to the preamble of claim 1.

[0010] Out of the JP S63 154207 A An arrangement for applying lubricant is known.

[0011] The invention is therefore based on the objective of a system comprising a shaft seal and a shaft seal with a lip for applying lubricant to further educate, with a view to improving environmental protection, in particular environmental safety against pollution.

[0012] According to the invention, the problem is solved by the system according to the provisions of claim 1, in the transmission according to the provisions of claim 10 and in the procedure according to the claim 11 solved by the specified characteristics.

[0013] The advantage of this method is that the targeted application of grease dots means that the smallest possible amount of grease is needed for lubrication. This also reduces the amount of grease that can leak into the environment, as only the smallest possible quantity of lubricant is used.

[0014] In an advantageous embodiment, the axial area covered by the first lip encompasses or at least overlaps the axial area covered by the first grease points, wherein the axial area covered by the second lip encompasses or at least overlaps the axial area covered by the second grease points. It is advantageous that grease is applied directly to each lip. This allows for the application of the smallest possible amount of grease. During operation, i.e., with the shaft inserted into the shaft seal, the grease points smear into one another, as each grease point is smeared in the circumferential direction or against the circumferential direction, particularly depending on the direction of rotation of the shaft.

[0015] According to the invention The first grease points are spaced axially, specifically in the axial direction, from the second grease points. An advantage of this is that the entire area does not need to be filled with grease, thus ensuring lubrication with a small amount of grease.

[0016] In a preferred embodiment, the amount of grease at each of the first grease points is greater than the amount of grease at each of the second grease points. It is advantageous that the sealing lip can be supplied with a larger amount of grease than the dust lip.

[0017] In an advantageous embodiment, the first grease spots are preferably spaced uniformly apart from each other in the circumferential direction, and / or the second grease spots are preferably spaced uniformly apart from each other in the circumferential direction. It is advantageous that an offset is permitted between the two rows formed by the grease spots, so that the distance between the first and second grease spots is as large as possible, thus preventing smearing in the axial direction.

[0018] In an advantageous embodiment, the number N of the first bold dots equals the number N of the second bold dots. An advantage of this is that an offset between the rows can be achieved. This is because, with unequal, especially coprime, numbers of bold dots, a uniform offset in the circumferential direction is not possible.

[0019] In an advantageous embodiment, the center of gravity of each first grease point is located at a first axial position, and the center of gravity of each second grease point is located at a second axial position, which is spaced apart from the first axial position. An advantage of this is that smearing of the first grease points by the second grease points can be prevented.

[0020] In an advantageous embodiment, the first lip is a sealing lip, and / or the second lip is a dust lip, dirt lip, or sealing lip. An advantage of this is that lubrication of the lips with a small amount of grease is possible.

[0021] In an advantageous embodiment, the arrangement of the first grease points, in particular the row formed by the first grease points, is offset circumferentially from the arrangement of the second grease points, in particular the row formed by the second grease points, in particular where the offset is 180° / N, where N is the number of first grease points. It is advantageous that the distance between the first and second grease points is chosen to be as large as possible, thus preventing smearing with the greatest possible probability. Therefore, the amount of lubricant applied to the respective lip is only available there.

[0022] Key features of the gearbox with shaft seal are that the gearbox has a housing part in which the shaft seal is accommodated, wherein a shaft projects through the shaft seal, wherein the first lip of the shaft seal seals towards the shaft, in particular wherein the first lip acts as a sealing lip, wherein oil is provided on the side of the first lip facing away from the room area, in particular wherein the first grease spots are applied to the side of the first lip facing the room area, in particular wherein the second lip of the shaft seal acts as a dust lip and / or dirt lip towards the shaft, wherein the second grease spots are applied to the side of the second lip facing the room area.

[0023] An advantage of this design is that the lip is lubricated with oil on one side and with grease on the other. The amount of grease used is minimal, thus ensuring maximum environmental safety even in the event of a leak.

[0024] Key features of the method for lubricating a shaft seal are that, in particular, a mandrel is used, In a first process step, the shaft seal having lips is pushed onto a mandrel, the mandrel having first and second recesses, the first being axially spaced from the second, the first being uniformly spaced from each other in the circumferential direction, and the second being uniformly spaced from each other in the circumferential direction, grease is forced out through the first and second recesses in a second process step, so that first grease spots are applied on a first side of a first lip and second grease spots are applied on a second side of a second lip, the first side facing an annular space which is bounded by the shaft seal and an imaginary cylinder whose outer radius is equal to the inner radius of the shaft seal.in particular, in a third process step, the shaft seal is removed from the mandrel, in particular, wherein the shaft seal is then received in a housing part of a gearbox, in particular, wherein in a fourth process step, the shaft seal is placed on a shaft whose outer diameter, in the axial area covered by the lips, is equal to the outer diameter of the cylinder, or this shaft is passed through the shaft seal.

[0025] The advantage here is that lubricant can be applied in a very short time, and the amount of lubricant can be dosed very precisely.

[0026] Further advantages arise from the dependent claims. The invention is not limited to the combination of features of the claims. For those skilled in the art, further meaningful combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent, in particular from the problem statement and / or the problem arising from a comparison with the prior art.

[0027] The invention will now be explained in more detail with reference to schematic illustrations: In the Figure 1 Figure 1 shows a cross-section through a shaft seal according to the invention, which is used to seal a rotatably mounted shaft in a housing part of a gearbox. Figure 2 A top view of an arrangement for applying lubricant to the sectioned shaft seal ring with mandrel 20 inserted is shown. In the Figure 3The cross-section through the shaft seal after lubricant application is shown.

[0028] As shown in the figures, the shaft seal 3 has a metallic support ring 3 which is overmolded in a base ring 1 made of plastic.

[0029] Thus, the shaft seal 3 can be manufactured in a single operation in which the support ring 3 is overmolded with plastic. The support ring 3 is preferably designed with an L-shaped cross-section, wherein a first leg of the L is oriented axially and the second in a radial direction.

[0030] The base ring is designed as a body of revolution with a U-shaped cross-section.

[0031] The radially inner leg of the axially open U-shape forms an annular leg area 1 of the body of revolution, i.e., the base ring.

[0032] On this leg area 1, a sealing lip 4 is formed that projects radially inwards towards the shaft to be sealed.

[0033] A ring spring 2 arranged on the radial outer circumference of the leg area presses, in particular shrinks, the sealing lip 4 onto the shaft.

[0034] The axial area covered by the ring spring 2 includes or overlaps the axial area covered by the sealing lip 4.

[0035] A dust lip 5 is formed on the leg area 1, projecting radially inwards towards the shaft to be sealed, and is axially spaced from the sealing lip 4.

[0036] The interior of the gearbox is at least partially filled with oil. The shaft seal is housed in a casing component of the gearbox.

[0037] Thus, oil is present on the side of the sealing lip 4 facing the interior of the gearbox.

[0038] For further lubrication of the shaft seal, grease is introduced into the annular space between dust lip 5 and sealing lip 4.

[0039] According to the invention, second grease spots 32, spaced apart from each other in the circumferential direction, are applied to the side of the dust lip 5 facing the annular space area, and first grease spots 31, spaced apart from each other in the circumferential direction, are applied to the side of the sealing lip 4 facing the annular space area and spaced axially from the second grease spots 32.

[0040] Preferably, the first fat dots 31 are regularly spaced apart from each other in the circumferential direction. Likewise, the second fat dots 32 are regularly spaced apart from each other in the circumferential direction.

[0041] Preferably, the number of first fat points 31 equals the number of second fat points 32.

[0042] As in Figure 3As shown, a circumferential offset is preferably provided between the row of fat points formed by the first fat points 31 and the row formed by the second fat points 32.

[0043] The amount of fat contained in a first fat point 31 is greater than the amount of fat contained in a second fat point 32.

[0044] As in Figure 2 As shown, to apply the fixed points (31, 32), the shaft seal is pushed onto a mandrel 20 and grease is pressed through first recesses 21 of the mandrel to apply the first grease points 31 and through second recesses 22 of the mandrel to apply the second grease points 32.

[0045] The axial direction is aligned parallel to the direction of rotation of the shaft protruding through the shaft seal. Likewise, the circumferential direction and the radial direction are also relative to this shaft.

[0046] In further embodiments of the invention, the shaft seal ring has a second sealing lip axially spaced from the sealing lip, with a third row of grease spots applied in the area of ​​the second sealing lip. Preferably, a respective row of grease spots is applied to each side of a respective lip facing the annular space, in particular a dust lip, protective lip, or grease lip. Thus, if a lip is axially surrounded on both sides by a space not filled with oil, grease is applied to both sides.

[0047] In further embodiments of the invention, the first recesses 21 are extended further in the circumferential direction than in the axial direction. Thus, the first grease points 31 are also extended further in the circumferential direction than in the axial direction. This is particularly advantageous when the first grease points 31 are applied to a sealing lip, since somewhat larger quantities of grease, i.e., grease points 31, are required there.

[0048] Alternatively or additionally, the second recesses 22 are extended further in the circumferential direction than in the axial direction. Thus, the second grease points 32 are also extended further in the circumferential direction than in the axial direction. Reference symbol list

[0049] 1 Leg area of ​​the base ring, in particular diaphragm 2 Ring spring 3 Support ring 4 Sealing lip 5 Dust lip 20 Mandrel 21 First recesses 22 Second recesses 31 First grease points 32 Second grease points

Claims

1. A system, having a shaft sealing ring and an arrangement for applying lubricant to the lipped shaft sealing ring with a mandrel (20), wherein an annular spatial region is formed axially, in particular in the axial direction, between a first lip and a second lip, in particular wherein the axial direction is oriented parallel to the direction of the ring axis of the shaft sealing ring, wherein the spatial region is limited by the shaft sealing ring and a notional cylinder having the internal diameter of the shaft sealing ring as an external diameter, characterised in that the mandrel (20) has first and second cutouts (21, 22), with the first ones being axially spaced apart from the second cutouts (22), with first grease dots (31) pressed out of the first cutouts (21) being applied on that side of the first lip which faces the spatial region, and with second grease dots (32) pressed out of the second cutouts (22) being applied on that side of the second lip which faces the spatial region, with the first grease dots (31) being spaced apart axially, i.e. in the axial direction, from the second grease dots (32).

2. A system according to claim 1, characterised in that the axial region covered by the first lip encompasses or at least overlaps with the axial region covered by the first grease dots (31, 32), with the axial region covered by the second lip encompassing or at least overlapping with the axial region covered by the second grease dots (32).

3. A system according to one of the preceding claims, characterised in that the respective amount of grease of the first grease dots (31) is greater than the respective amount of grease of the second grease dots (32).

4. A system according to one of the preceding claims, characterised in that the first grease dots (31) are preferably uniformly spaced apart from each other in the peripheral direction, and / or in that the second grease dots (32) are preferably uniformly spaced apart from each other in the peripheral direction.

5. A system according to one of the preceding claims, characterised in that the number N of the first grease dots (31) is equal to the number N of the second grease dots (32).

6. A system according to one of the preceding claims, characterised in that the respective centre of mass of the respective first grease dot is arranged at a first axial position and in that the respective centre of mass of the respective second grease dot is arranged at a second axial position which is spaced apart from the first axial position.

7. A system according to one of the preceding claims, characterised in that the first lip is a sealing lip (4), and / or in that the second lip is a dust lip (5), dirt lip or sealing lip (4).

8. A system according to one of the preceding claims, characterised in that the arrangement of the first grease dots (31), in particular therefore the row formed by the first grease dots (31), has an offset in the peripheral direction to the arrangement of the second grease dots (32), in particular therefore the row formed by the second grease dots (32), in particular with the offset being 180° / N, where N is the number of the first grease dots (31).

9. A system according to one of the preceding claims, characterised in that the first and / or second grease dots (31, 32) extend more in the peripheral direction than in the axial direction.

10. A gear unit with a system according to one of the preceding claims, characterised in that the gear unit has a housing part in which the shaft sealing ring is received, with a shaft protruding through the shaft sealing ring, with the first lip of the shaft sealing ring sealing off towards the shaft, in particular with the first lip acting as a sealing lip (4), with oil being provided on that side of the first lip which faces away from the spatial region, in particular with the first grease dots (31) being applied on that side of the first lip which faces the spatial region, in particular with the second lip of the shaft sealing ring towards the shaft as a dust lip (5) and / or dirt lip, with the second grease dots (32) being applied on that side of the second lip which faces the spatial region.

11. A method for lubricating a shaft sealing ring by means of a mandrel (20), characterised in that in a first method step the lipped shaft sealing ring is pushed onto the mandrel (20), with the mandrel (20) having first and second cutouts (21, 22), with the first ones being axially spaced apart from the second cutouts (22), with the first cutouts (21) being in particular uniformly spaced apart from each other in the peripheral direction, and with the second cutouts (22) being in particular uniformly spaced apart from each other in the peripheral direction, in a second method step grease is pressed out through the first and second cutouts (21, 22), so that first grease dots (31) are applied on a first side of a first lip and second grease dots (32) are applied on a second side of a second lip, with the first side facing an annular spatial region which is limited by the shaft sealing ring and a notional cylinder, the external radius of which is equal to the internal radius of the shaft sealing ring.

12. A method according to one of the preceding claims, characterised in that in a third method step the shaft sealing ring is removed from the mandrel (20), in particular with thereafter the shaft sealing ring being received in a housing part of a gear unit.

13. A method according to one of the preceding claims, characterised in that in a fourth method step the shaft sealing ring is mounted on a shaft, the external diameter of which, in the axial region covered by the lips, is equal to the external diameter of the cylinder, or this shaft is inserted through the shaft sealing ring.

14. A method according to one of the preceding claims, characterised in that the first and / or second cutouts (21, 22) are extended further in the peripheral direction than in the axial direction, in particular such that the first and / or second grease dots (31, 32) are extended further in the peripheral direction than in the axial direction.