KR102417576B1 - Wave gear and bearing element for a wave gear - Google Patents

Abstract

The invention relates to a wave gear for a robot gear, comprising at least one bearing element (1) having an inner ring (2) and an outer ring (3), in this case an inner ring (2) or an outer ring (3) ) is formed in a divided state, and in this case, two axially inclined needle cages 4a, 4b axially adjacent and guided therein by the needle roller 5 are spatially formed in the inner ring 2 ) and the outer ring (3). The invention also relates to a bearing element (1) for a wave gear, comprising an inner ring (2) and an outer ring (3), in which case the inner ring (2) or the outer ring (3) is divided In this case, two axially inclined needle cages 4a, 4b, which are axially adjacent and in which the needle roller 5 are guided, spatially form an inner ring 2 and an outer ring. (3) is arranged between them.

Description

WAVE GEAR AND BEARING ELEMENT FOR A WAVE GEAR

The present invention relates to a wave gear for a robot gear comprising at least one bearing element having an inner ring and an outer ring, wherein at least one bearing cage is spatially arranged between the inner ring and the outer ring, In the bearing cage, the rolling body is guided annularly. The invention also relates to a bearing element for a wave gear.

DE 10 134 191 A1 discloses a gear unit comprising a ring-shaped housing and a reduction mechanism housed therein. The gear unit also comprises a rolling bearing for rotationally mounting the output element of the reduction mechanism on the housing, wherein the rolling bearing comprises an outer ring fixed on the housing, an inner ring present on the output element and a plurality of rolling bodies to provide The outer circumferential face of the outer ring is provided with a male threaded section, while the inner circumferential face of the housing is provided with a female section matching the male threaded section, the outer running ring being screwed onto the housing.

It is an object of the present invention to improve wave gears and bearing elements for wave gears so as to achieve a high level of tilting stiffness and low friction torques, while at the same time simple assembly.

The said subject is solved by the subject of patent claim 1 and patent claim 10. Preferred embodiments can be presented from the dependent claims, the detailed description and the respective drawings.

A wave gear according to the invention for a robot gear comprises at least one bearing element having an inner ring and an outer ring, in this case the inner ring or the outer ring being formed in a divided state, and in this case axially Two axially inclined needle cages adjacent and in which the needle rollers are guided are spatially arranged between the inner ring and the outer ring. In other words, the bearing element has two axially adjacent rows of axially inclined needle bearings, in which case each row of axially inclined needle bearings is an axially inclined needle cage having an annularly guided needle roller therein. is done By means of a bearing element designed in this way, it is possible to transmit large forces in the radial and axial directions, in which case low friction torques and relatively high tilting stiffnesses can be reached. In particular, the assembly of the wave gear or bearing element is simplified.

The bearing element is preferably provided as an output bearing of the wave gear or is part of an output bearing. Preferably, the bearing element is designed as a two-row self-locking axially inclined needle bearing, in which case a plurality of needle rollers are mounted in an axially inclined needle cage between the outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring. They are arranged and rolled in a spatially spaced state by In other words, two rows of symmetrical inclined needle rows are arranged axially adjacent to each other inside the bearing element, in which case the two rows of axial inclined needle bearings can absorb large radial loads and axial loads from both sides . By means of the two rows of axial inclined needle bearings, a high level of rigidity of the bearing element is achieved.

The designation of a segmented inner ring or a segmented outer ring should be understood to mean that the inner ring is formed of a plurality of inner ring segments or that the outer ring is formed of a plurality of outer ring segments.

According to one embodiment, the inner ring consists of a first and a second inner ring segment, in which case two axially inclined needle cages are arranged in an O relative to one another. In particular, the inner ring segments are axially adjacent and arranged coaxially with each other. In this case, when assembling the bearing element, the axially inclined needle cage is first inserted into the one-piece outer ring, and then the inner ring segments, ie the inner ring halves, are assembled. These inner ring halves can be screwed together, for example.

According to another embodiment, the outer ring consists of a first and a second outer ring segment, in which case two axially inclined needle cages are arranged in an X-array with respect to each other. In particular, the outer ring segments are axially adjacent and arranged coaxially with each other. In this case, when assembling the bearing element, the axially inclined needle cage is first inserted into the one-piece inner ring, and then the outer ring segments, ie the outer ring halves, are assembled. These outer ring halves can be held in place by screwing, similar to an O-shaped arrangement.

In particular, if the bearing element is formed of a one-piece inner ring and a divided outer ring, the bearing element must be protected from unwanted release of lubricants due to centrifugal forces generated during operation.

For this purpose, an O-ring is arranged between the first and second outer ring segments. The O-ring is at least partially received, for example, in an annular groove on the first and/or second outer ring segment, in order to achieve a sealing effect.

Alternatively or supplementally, a liquid seal is arranged between the first outer ring segment and the second outer ring segment. The liquid seal may serve the same effect as the O-ring, or may further support or improve the sealing effect.

Furthermore, alternatively or supplementally, caulking contours are formed on the first and/or second outer ring segments, which caulking contours respectively have corresponding caulking contours formed on the opposite first or second outer ring segments. tangent to the contour. The caulking contour extends substantially axially or parallel to the axis of rotation of the bearing element and prevents radial oil drain between the outer ring segments. If a caulking contour is formed on the first outer ring segment, this caulking contour is tangent to a corresponding contour formed on the second outer ring segment. Conversely, if a caulking contour is formed on the second outer ring segment, this caulking contour is tangent to a corresponding contour formed on the first outer ring segment.

The caulking contour is designed to deform elastically and/or plastically, in particular in order to realize a sufficient sealing effect at the contact surface between the caulking contour and the corresponding contour during the screwing of the two outer ring segments or during assembly . For this purpose, the caulking profile has a contact tip formed at an acute angle, which, for example, is elastically and/or plastically deformed during assembly. In other words, the caulking contour is preferably formed softer than the corresponding contour. In this way, the caulked contour has a material with less resistance to elastic and/or plastic deformation than the corresponding contour.

Alternatively, the corresponding contour is formed softer than the caulking contour. In this case, the mating contour is elastically and/or plastically deformed in order to realize a sufficient sealing effect at the contact surface between the caulking contour and the mating contour during screwing of the two outer ring segments or during assembly. For this purpose, for example, the contact tip of the caulking contour is inserted through the surface of the corresponding contour, which is elastically and/or plastically deformed during assembly. Additionally, the mating contour may already be equipped with notches or grooves for accommodating and guiding the caulking contour. In this case, the contact surfaces between the mating contour and the caulking contour are designed to correspond to each other.

Alternatively, it is also conceivable that the caulking contour and the corresponding contour are also designed to be smooth, so that the corresponding sealing surface for sealing is produced by elastic and/or plastic deformation of the caulking contour and the corresponding contour as a result. have.

According to an alternative or complementary embodiment, a lubricant mixture consisting of at least a lubricant and a polymer is spatially arranged between the inner ring and the outer ring. The lubricant mixture makes it possible that additional parts or substances for achieving the sealing effect can be dispensed with. The lubricant mixture is preferably arranged in the region of the axially inclined needle cage, in the region of the roller pass of the needle roller and/or in the region of the sealing surface if caulking contours and corresponding contours are provided. Lubricant mixtures in particular perform a dual function. On the one hand, the lubrication during the pivoting operation of the wave gear is improved, and on the other hand, radial discharge of the lubricant is effectively prevented. Lubricant mixtures are also referred to as lubricant compounds, which generally consist of a porous polymer and a lubricant. Alternatively, instead of such lubricant mixtures, fatty lubricants, oil lubricants or solid lubricants may be used.

A bearing element according to the invention for a wave gear comprises an inner ring and an outer ring, in which case the inner ring or the outer ring is formed in a divided state, and in this case axially adjacent and needle rollers are Two axially inclined needle cages guided therein are spatially arranged between the inner ring and the outer ring.

Further measures for improving the invention are explained in more detail below, together with a description of three preferred embodiments of the invention with reference to the four drawings, in which the same or similar parts are provided with the same reference numerals has been in the drawing section,
1 shows a simplified schematic cross-sectional view of a bearing element according to the invention for a wave gear according to a first embodiment,
2 shows a simplified schematic cross-sectional view of a bearing element according to the invention according to a second embodiment,
3 shows a simplified schematic detailed sectional view of a bearing element according to the invention according to FIG. 2 , and
4 shows a highly simplified schematic detailed cross-sectional view for illustrating two outer ring segments adjacent to each other of a bearing element according to the invention according to a third embodiment;

1 to 3 , the bearing element 1 according to the invention for a wave gear, not shown in these figures, comprises an inner ring 2 and an outer ring 3 , in this case axially Two axially inclined needle cages 4a , 4b adjacent and guided therein by the needle roller 5 are spatially arranged between the inner ring 2 and the outer ring 3 . In other words, the bearing element 1 is in this case designed as two rows of axial inclined needle bearings, in the present case two rows of rolling bodies 12a, 12b arranged axially offset with respect to each other. ), in which case the needle rollers 5 of the first rolling body row 12a are arranged symmetrically to the needle rollers 5 of the second rolling body row 12b. The bearing element 1 also has a sealing element 10 for axial sealing of the bearing element 1 .

According to the first embodiment according to FIG. 1 , the outer ring 3 is designed in partial shape, in which case the inner ring 2 is divided, ie the first and second inner ring segments 2a, 2b. ) is formed. In this case, in order to simplify the assembly of the bearing element 1 and to increase the tilting rigidity of the bearing element 1 , the two axially inclined needle cages 4a , 4b are arranged in an O relative to each other. are arranged. For this purpose, the axially inclined needle cage 4a, 4b is first inserted into the one-piece outer ring, and subsequently the two inner ring segments 2a, 2b are assembled and, for example, screwed into one another . Preferably, in this configuration of the bearing element 1 , the lubricant cannot drain out radially due to the action of centrifugal force.

2 to 4 , the inner ring 2 is formed in a partial shape, and the outer ring 3 is formed in a divided state, that is to say, the first and second outer ring segments 3a and 3b. is formed with In this case, in order to simplify assembly, the two axially inclined needle cages 4a, 4b are arranged in an X-shaped arrangement with respect to each other.

According to a second exemplary embodiment according to FIGS. 2 and 3 , an O-ring 6 is arranged between the first outer ring segment 3a and the second outer ring segment 3b . The two outer ring segments 3a, 3b each have one axial guide section 11a, 11b, which guide sections are arranged overlapping each other in the radial direction. In this embodiment, the axial guide section 11a of the first outer ring segment 3a radially surrounds the axial guide section 11b of the second outer ring segment 3b. An O-ring is arranged radially between the two guide sections 11b and is received in the present case on the guide section 11a of the first outer ring segment 3 . Alternatively or complementary, providing a liquid seal, not shown in these figures, between the first outer ring segment 3a and the second outer ring segment 3b, in order to supplement or improve the sealing effect. can think of Also, instead of the O-ring 6, a press fit between the two guide sections 11a, 11b of the outer ring segments 3a, 3b or between the two outer ring segments 3a, 3b ( It is also conceivable to provide a press fit.

In the present case, a lubricant mixture 7 consisting of at least a lubricant and a porous polymer is spatially arranged between the inner ring 2 and the outer ring 3 . Lubricant mixtures, also referred to as lubricant compounds, may be used in conjunction with other seals, such as eg O-rings, or may be used separately without additional seals, thereby reducing manufacturing and maintenance costs. Bearing elements 1 lubricated with a lubricant mixture have the same load rating compared to bearings lubricated with standard grease and operate substantially without maintenance. The lubricant mixture forms an additional barrier against contamination of the rolling contact between the rolling body and the roller pass. In addition, the lubricant mixture is better bonded in the bearing element 1 , thereby reducing the risk that the lubricant can be drained.

According to a third embodiment according to FIG. 4 , a caulking profile 8 formed as a contact tip is formed on the second guide section 11b of the second outer ring segment 3b, the caulking profile being opposite Abuts the corresponding contour 9 formed on the first outer ring segment 3a. Alternatively, the caulking contour 8 can also be formed on the first guide section 11a of the first outer ring segment 3a, in which case the corresponding contour 9 is formed on the second outer ring segment 3b is formed correspondingly to the phase. In this case, the corresponding contour 9 is formed softer than the caulking contour 8 . This formation means that when assembling the bearing element 1 , the caulking contour 8 is inserted axially through the corresponding contour 9 and plastically deformed again in order to achieve the desired sealing effect. Alternatively, the caulking contour 8 can be formed softer than the corresponding contour 9 , so that the caulking contour 8 is plastically deformed relative to the corresponding contour 9 . Alternatively, the corresponding contour 9 may also be formed complementary to the caulking contour 8 . In other words, the corresponding contour 9 and the caulking contour can have corresponding contact surfaces which can be formed in a substantially flat or curved shape. For example, the corresponding contour 9 may have a convex curvature and the caulking contour 8 may have a corresponding concave curvature.

1: Bearing element
2: inner ring
2a, 2b: inner ring segment
3: outer ring
3a, 3b: outer ring segment
4a, 4b: Axial inclined needle cage
5: Needle roller
6: O-ring
7: lubricant mixture
8: Caulking configuration
9: Corresponding configuration
10: sealing element
11a, 11b: Guide section
12a, 12b: rolling body rows

Claims (10)

A wave gear for a robot gear comprising one or more bearing elements (1) having an inner ring (2) and an outer ring (3), the inner ring (2) or the outer ring (3) being formed in a divided state, Two axially inclined needle cages 4a, 4b axially adjacent and guided in the needle roller 5 are spatially arranged between the inner ring 2 and the outer ring 3,
The inner ring 2 consists of first and second inner ring segments 2a, 2b, the two axially inclined needle cages 4a, 4b being arranged in an O-array with respect to each other,
The outer ring (3) consists of first and second outer ring segments (3a, 3b), characterized in that the two axially inclined needle cages (4a, 4b) are arranged in an X-array with respect to each other wave gear for robot gear. delete delete According to claim 1,
Wave gear, characterized in that an O-ring (6) is arranged between the first outer ring segment (3a) and the second outer ring segment (3b). 5. The method of claim 1 or 4,
Wave gear, characterized in that a liquid seal is arranged between the first outer ring segment (3a) and the second outer ring segment (3b). 5. The method of claim 1 or 4,
A caulking profile 8 is formed on at least one of the first outer ring segment 3a and the second outer ring segment 3b, the caulking profile being respectively opposite the first or second outer ring segment 3a , 3b), characterized in that it is tangent to the corresponding contour (9) formed on it. 7. The method of claim 6,
Wave gear, characterized in that the caulking contour (8) is formed smoother than the corresponding contour (9). 7. The method of claim 6,
Wave gear, characterized in that the corresponding contour (9) is formed smoother than the caulking contour (8). 5. The method of claim 1 or 4,
Wave gear, characterized in that a lubricant mixture (7) consisting of at least a lubricant and a polymer is spatially arranged between the inner ring (2) and the outer ring (3). A bearing element (1) for a wave gear comprising an inner ring (2) and an outer ring (3), wherein the inner ring (2) or the outer ring (3) is formed in a divided state, adjacent in the axial direction and needle Two axially inclined needle cages 4a, 4b, in which the roller 5 is guided, are spatially arranged between the inner ring 2 and the outer ring 3,
The inner ring 2 consists of first and second inner ring segments 2a, 2b, the two axially inclined needle cages 4a, 4b being arranged in an O-array with respect to each other,
The outer ring (3) consists of first and second outer ring segments (3a, 3b), characterized in that the two axially inclined needle cages (4a, 4b) are arranged in an X-array with respect to each other which, bearing elements for wave gears (1).

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