Crossed roller bearing and bearing type differential device with same

Abstract

The utility model relates to the technical field of differential gears, in particular to a crossed roller bearing and a bearing type differential gear with the crossed roller bearing. The outer ring of the crossed roller bearing and the shell are combined into a part to form a new shell, so that the number of parts is reduced, the rigidity of the device is improved, and the bearing capacity of the device is further improved. Annular grooves are formed in the end face of the rear cover and the end face of the corresponding middle disc, and first balls are arranged in the annular grooves. When the input shaft rotates, the middle disc begins to swing under the action of the annular groove and the first balls, the output flange generates a differential effect relative to the input shaft under the action of meshing of the output flange track groove and the second balls, and the output flange decelerates and outputs the rotating speed. By means of the structure, the middle disc is supported, eccentric rotation of the input shaft is converted into concentric rotation of the output flange, transmission of the device is stable, and transmission efficiency and precision are improved.

Description

Technical Field

[0001] This utility model relates to the field of differential gear technology, and more specifically to a crossed roller bearing and a bearing-type differential gear having thereon. Background Technology

[0002] Traditional cycloidal bearing-based differential gears have several design limitations that significantly restrict their performance and application range. Firstly, their internal structure comprises numerous parts, increasing manufacturing complexity and cost, and making assembly cumbersome and time-consuming. Furthermore, this complex structure often results in poor rigidity; combined with gaps between parts, wear, and variations in material properties, this leads to issues such as speed fluctuations, poor load-bearing capacity, and uneven output during operation. Clearly, this is not an ideal choice for applications requiring long-term operation or high reliability. Utility Model Content

[0003] This utility model provides a crossed roller bearing and a bearing-type differential device thereof, the purpose of which is to reduce the number of parts, improve the rigidity of the differential device, and thus improve its load-bearing capacity.

[0004] The above objectives are achieved through the following technical solutions:

[0005] A crossed roller bearing includes an output flange, a first V-shaped annular groove on the outer ring of the output flange, a housing fitted on the output flange, a second V-shaped annular groove on the inner ring of the housing, the second V-shaped annular groove and the first V-shaped annular groove forming a raceway, and crossed rollers evenly distributed in the raceway.

[0006] The crossed rollers are multiple cylindrical rollers evenly distributed in the raceway. Any two adjacent cylindrical rollers intersect at a 45° angle to form a cross, so that the output flange and the housing have rolling friction with each cylindrical roller.

[0007] A sealing ring is provided between the output flange and the housing, and the sealing ring is blocked on the left side of the crossed rollers.

[0008] A bearing-type differential device includes a crossed roller bearing and a rear cover. The left end of the rear cover has a plurality of first annular grooves evenly distributed around its circumference. A middle disk is provided on the left side of the rear cover. The right end of the middle disk has a plurality of second annular grooves evenly distributed around its circumference. A first ball is disposed in the first annular groove and is inserted into the second annular groove. The left end of the middle disk has a plurality of ball sockets evenly distributed around its circumference, and each ball socket contains a second ball.

[0009] The right end of the output flange is provided with a track groove, and all the second balls are engaged in the track groove. The number of second balls is at least one more than the number of teeth on the track groove. The right end of the housing is fixedly connected to the rear cover.

[0010] The number of first annular grooves is the same as the number of second annular grooves, and their positions correspond one-to-one, so that each first annular groove contains a first ball bearing, and all the first balls bearings are also respectively installed in the second annular grooves. The cross-sections of the first annular grooves and the second annular grooves are the same, which are two symmetrical arcs, and the diameter of the first ball bearing is the same as that of the arc.

[0011] The edge of the track groove is formed by two curves or two cycloids, and evenly distributed groove-shaped teeth are formed between the two curves or two cycloids. The second ball can roll in the track groove to achieve rolling friction between the second ball and the output flange.

[0012] It also includes the aforementioned differential transmission disc assembly, and a hollow input shaft. From right to left, the outer circumferential surface of the input shaft has a first central profile surface, an eccentric profile surface, and a second central profile surface. The axis of the eccentric profile surface is parallel to and at a distance from the central rotation axis of the input shaft. This distance is denoted as _____. The rear cover, intermediate plate, and output flange are rotatably connected to the first central profile surface, the eccentric profile surface, and the second central profile surface, respectively. A base is fixed to the right end of the rear cover. The center distance between the two symmetrical arcs on the cross-section of the second annular groove is denoted as... 2, 2.

[0013] The rear cover, intermediate plate, and output flange are each rotatably connected to the first central profile surface, the eccentric profile surface, and the second central profile surface via a bearing.

[0014] The right end of the input shaft has evenly distributed open slots around its circumference, and a bushing is fixedly connected to the input shaft. The bushing has two free ends.

[0015] A first sealing ring mounting groove is formed between the input shaft and the rear cover. The first sealing ring mounting groove is located on the right side of the first bearing. The first sealing ring is installed in the first sealing ring mounting groove. A second sealing ring mounting groove is formed between the output flange and the housing. The second sealing ring mounting groove is located on the left side of the crossed rollers. The second sealing ring is installed in the second sealing ring mounting groove.

[0016] The beneficial effects of this utility model of a crossed roller bearing and a bearing-type differential device thereof are as follows:

[0017] One of the core components of the bearing-type differential gear unit is the crossed roller bearing. The outer ring of the crossed roller bearing is integrated with the housing to form a new housing, reducing the number of parts, increasing the rigidity of the device, and thus improving its load-bearing capacity. Both the rear cover and the end face of the corresponding intermediate disc have annular grooves, within which the first rolling balls are installed. When the input shaft rotates, the intermediate disc begins to oscillate under the action of the annular grooves and the first rolling balls. Furthermore, under the action of the output flange track groove and the engagement of the second rolling ball, the output flange generates a differential speed effect relative to the input shaft, thus reducing the output speed. This structure not only supports the intermediate disc but also converts the eccentric rotation of the input shaft into the concentric rotation of the output flange, making the transmission stable and improving transmission efficiency and accuracy. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of a bearing-type differential device;

[0019] Figure 2 This is a cross-sectional view of the input shaft;

[0020] Figure 3 and 4 This is a schematic diagram of the back cover structure;

[0021] Figure 5 and 6 This is a schematic diagram of the intermediate disk structure;

[0022] Figures 7 to 9 This is a schematic diagram of the output flange structure;

[0023] Figure 10 and 11 This is a schematic diagram of the shell structure;

[0024] Figure 12 This is a cross-sectional view of the shell;

[0025] Figure 13 and 14 This is a schematic diagram of the base structure;

[0026] Figure 15 This is a schematic diagram of the bushing structure;

[0027] Figure 16 This is a schematic diagram of an arc;

[0028] Figure 17 for Figure 1 Enlarged view of point A in the middle;

[0029] Figure 18 This is a schematic diagram showing the fit between the bearing cage and the bearing rollers.

[0030] In the diagram: 1-1, Input shaft; 1-2, First central profile surface; 1-3, Eccentric profile surface; 1-4, Second central profile surface; 1-5, Opening slot; 2-1, Rear cover; 2-2, Rear cover flange; 2-3, First annular groove; 3-1, Intermediate disc; 3-2, Second annular groove; 3-3, Ball socket; 4-1, Output flange; 4-2, Track groove; 4-3, First V-shaped annular groove; 4-4, Output flange partition surface; 5-1, Housing; 5-2, Second V-shaped annular groove; 6-1, Base; 6-2, Process hole; 7-1, Bushing; 7-2, Mounting hole; 7-3, Bolt hole; 8-1, Bearing cage; 8-2, Bearing roller. Detailed Implementation

[0031] A bearing-type differential device includes a hollow input shaft 1-1. From right to left, the outer circumference of the input shaft 1-1 is provided with a first central profile surface 1-2, an eccentric profile surface 1-3, and a second central profile surface 1-4. The rotation axis of the inner ring of the input shaft 1-1 is the central rotation axis. The axes of the first central profile surface 1-2 and the second central profile surface 1-4 coincide with the central rotation axis. The axis of the eccentric profile surface 1-3 is parallel to the central rotation axis of the input shaft 1-1 and there is a certain distance between them. This distance is the eccentricity of the input shaft 1-1 or the eccentric profile surface 1-3. The inner ring of the first bearing is mounted on the first central contour surface 1-2. An output shaft first shoulder is integrally formed on the outer ring wall of the input shaft 1-1, which restricts the left-side degree of freedom of the first bearing. A rear cover 2-1 is mounted on the outer ring of the first bearing, allowing the rear cover 2-1 to be rotatably connected to the input shaft 1-1. A rear cover flange 2-2 is integrally formed on the inner wall of the rear cover 2-1, abutting against the right end of the first bearing. Multiple first annular grooves 2-3 are evenly distributed around the left circumference of the rear cover 2-1. The inner ring of the second bearing is mounted on the eccentric contour surface 1-3. A second shoulder and a third shoulder are integrally formed on the outer ring wall of the input shaft 1-1, respectively restricting the left and right-side degrees of freedom of the second bearing. An intermediate disk 3-1 is mounted on the outer ring of the second bearing, allowing the intermediate disk 3-1 to be rotatably connected to the input shaft 1-1. The right end circumference of the intermediate disk 3-1 is evenly distributed with second annular grooves 3-2. The cross-sections of the first annular grooves 2-3 and the second annular grooves 3-2 are the same, consisting of two symmetrical arcs, for example... Figure 16The center distance E2 between the two symmetrical arcs is the eccentricity of the eccentric profile surface 1-3. The number of first annular grooves 2-3 and the number of second annular grooves 3-2 are the same and their positions correspond one-to-one, so that each first annular groove 2-3 contains a first ball, and all the first balls are also respectively installed in the second annular grooves 3-2. The left end circumference of the intermediate disk 3-1 is evenly distributed with multiple ball sockets 3-3, each ball socket 3-3 contains a second ball. The inner ring of the third bearing is installed on the second eccentric profile surface 1-4, and the outer ring of the third bearing is equipped with an output flange 4-1. The right end of the output flange 4-1 is provided with a track groove 4-2, and all the second balls mesh in the track groove 4-2. The number of second balls is at least one more than the number of teeth on the track groove 4-2. A fourth shoulder is integrally formed on the outer peripheral wall of the input shaft 1-1, which restricts the right-side degree of freedom of the third bearing. An output flange partition surface 4-4 is integrally formed on the inner wall of the output flange 4-1, and an output flange shoulder is integrally formed on the inner wall of the output flange 4-1, restricting the left-side degree of freedom of the third bearing. The output flange shoulder is located to the right of the output flange partition surface 4-4. A first V-shaped annular groove 4-3 is formed on the outer wall of the output flange 4-1, and crossed rollers are evenly distributed within the first V-shaped annular groove 4-3, i.e., multiple rollers are circumferentially evenly distributed within the first V-shaped annular groove 4-3 in a cross-shaped arrangement at a 45° angle. The crossed roller bearing includes the aforementioned housing 5-1, output flange 4-1, and crossed rollers.

[0032] The left end of the rear cover 2-1 is bolted to the housing 5-1, which is fitted onto the intermediate plate 3-1 and the output flange 4-1. A second V-shaped annular groove 5-2 is formed on the inner wall of the housing 5-1, which, together with the first V-shaped annular groove 4-3, forms a complete raceway. Crossed rollers are located in the raceway. The right end of the housing 5-1 is bolted to the rear cover 2-1, which is bolted to the base 6-1. The right side of the input shaft 1-1 and the rear cover 2-1 are located inside the base 6-1. The inner ring of the left end of the base 6-1 mates with the outer ring of the right end of the rear cover 2-1. The base 6-1 restricts the right-side freedom of the rear cover 2-1, and the housing 5-1 restricts the left-side freedom of the output flange 4-1.

[0033] In more detail, the right end of the base 6-1 has evenly distributed threaded holes and countersunk holes, so that the motor is fixed to the threaded holes of the base 6-1 by bolts, and the countersunk holes of the base 6-1 are fixed to the rear cover 2-1 by bolts.

[0034] Preferably, the bushing 7-1 has two free ends. The bushing 7-1 is fitted onto the outer ring of the right side of the input shaft 1-1. The output shaft of the motor is rotatably connected to the inner ring of the input shaft 1-1. There is a mounting hole 7-2 at one free end of the bushing 7-1. The tail of the bolt passes through the mounting hole 7-2 first, and the head of the bolt abuts against the structure of the bushing 7-1 at the mounting hole 7-2. There is a threaded hole at the other free end of the bushing 7-1. The tail of the bolt is screwed into the threaded hole, thereby reducing the inner diameter of the bushing 7-1. The right end of the input shaft 1-1 has evenly distributed open slots 1-5, which allows the bushing 7-1 to clamp onto the input shaft 1-1, reducing the inner diameter of the right side of the input shaft 1-1 and clamping the motor shaft onto the inner ring of the input shaft 1-1. This facilitates the transmission of the motor shaft's rotational speed to the input shaft and also makes installation easier. A key structure can also be formed on the motor shaft, so that the key structure is placed in the opening slot 1-5, so that when the inner diameter of the input shaft 1-1 is reduced, it can still be clamped on the key, which is beneficial for transmission.

[0035] The base 6-1 has a radially extending process hole 6-2, which allows tools to be inserted into the process hole 6-2 to tighten the bolts passing through the mounting hole 7-2. The bushing 7-1 has a bolt hole 7-3. The bolt is screwed into the bolt hole 7-3 by threading it into the bushing 7-1, so that the tail of the bolt rests on the opening groove 1-5, preventing the bushing (7-1) from rotating relative to the opening groove 1-5.

[0036] To improve sealing, a first sealing ring mounting groove is formed between the input shaft 1-1 and the rear cover 2-1. This groove is located to the right of the first bearing and contains the first sealing ring. A second sealing ring mounting groove is formed between the output flange 4-1 and the housing 5-1. This groove is located to the left of the crossed rollers and contains the second sealing ring. This structure also reduces the number of sealing rings used.

[0037] Regarding the bearings, conventional bearings can be used, with the two parts respectively fixed to the inner or outer ring of the bearing to achieve a so-called rotational connection. To reduce the size of the reducer, an annular bearing cage 8-1 can also be used. The bearing cage 8-1 has evenly distributed bearing mounting slots around its circumference, and each bearing mounting slot houses a bearing roller 8-2. The bearing roller 8-2 is parallel to the axis of the bearing cage 8-1, allowing the two parts to directly experience rolling friction with the bearing roller 8-2. For example, the bearing cage 8-1 rests on the outer ring of the second and third shoulders, and the bearing roller 8-2's axial freedom is restricted by the second and third shoulders. The input shaft 1-1 experiences rolling friction with the side of the bearing roller 8-2 closest to the axis, and the bearing roller 8-2 experiences rolling friction with the side of the bearing roller 8-2 closest to the intermediate disc 3-1.

[0038] During operation, the motor spindle drives the input shaft 1-1 to rotate. The eccentric profile surface 1-3 of the input shaft 1-1, through the second bearing, causes the intermediate disk 3-1 to oscillate eccentrically relative to the axis of rotation of the central portion. Due to the engagement of the second ball bearing in the ball socket 3-3 with the track groove 4-2, and the rotation of the first ball bearing in the second annular groove 3-2, the intermediate disk 3-1 oscillates relative to the axis of rotation of the eccentric portion. The oscillation of the intermediate disk 3-1 is transmitted to the output flange 4-1 via the second ball bearing, causing the output flange 4-1 to rotate at a reduced speed around the central axis of rotation, thus outputting the rotational speed. The first ball bearing in the first annular groove 2-3 also provides support for the intermediate disk 3-1, ensuring the smooth operation of the entire reducer.

Claims

1. A crossed roller bearing, characterized in that, It includes an output flange (4-1), a first V-shaped annular groove (4-3) is provided on the outer ring of the output flange (4-1), a housing (5-1) is fitted on the output flange (4-1), a second V-shaped annular groove (5-2) is provided on the inner ring of the housing (5-1), the second V-shaped annular groove (5-2) and the first V-shaped annular groove (4-3) form a raceway, and cross rollers are evenly distributed in the raceway. A track groove (4-2) is provided on the right end of the output flange (4-1).

2. The crossed roller bearing according to claim 1, characterized in that, The crossed rollers are multiple cylindrical rollers evenly distributed in the raceway. Any two adjacent cylindrical rollers intersect at a 45° angle to form a cross, so that the output flange (4-1) and the housing (5-1) have rolling friction with each cylindrical roller.

3. The crossed roller bearing according to claim 1, characterized in that, A sealing ring is provided between the output flange (4-1) and the housing (5-1), and the sealing ring is blocked on the left side of the cross rollers.

4. A bearing-type differential device, characterized in that, Includes a back cover (2-1), with multiple first annular grooves (2-3) evenly distributed around the left circumference of the back cover (2-1), a middle disk (3-1) on the left side of the back cover (2-1), and a second annular groove (3-2) evenly distributed around the right circumference of the middle disk (3-1). A first ball is disposed in the first annular groove (2-3) and is inserted into the second annular groove (3-2). The middle disk (3-1) has multiple ball sockets (3-3) evenly distributed around the left circumference of the middle disk (3-1), and each ball socket (3-3) contains a second ball. It also includes the cross roller bearing as described in claim 1, wherein all the second balls are engaged in the track groove (4-2), the number of second balls is at least one more than the number of teeth on the track groove (4-2), and the right end of the housing (5-1) is fixedly connected to the rear cover (2-1). The number of first annular grooves (2-3) is the same as the number of second annular grooves (3-2), and their positions correspond one-to-one, so that each first annular groove (2-3) contains a first ball bearing, and all the first balls bearings are also respectively installed in the second annular grooves (3-2). The cross-sections of the first annular grooves (2-3) and the second annular grooves (3-2) are the same, which are two symmetrical arcs, and the diameter of the first ball bearing is the same as that of the arc.

5. The bearing-type differential device according to claim 4, characterized in that, The edge of the track groove (4-2) is formed by two curves or two cycloids, and evenly distributed groove-shaped teeth are formed between the two curves or two cycloids. The second ball can roll in the track groove (4-2) to achieve rolling friction between the second ball and the output flange (4-1).

6. The bearing-type differential device according to claim 5, characterized in that, It also includes a hollow input shaft (1-1). From right to left, the outer circumferential surface of the input shaft (1-1) is provided with a first central profile surface (1-2), an eccentric profile surface (1-3), and a second central profile surface (1-4). The axis of the eccentric profile surface (1-3) is parallel to and at a distance from the central rotation axis of the input shaft (1-1). This distance is denoted as _____. The rear cover (2-1), intermediate plate (3-1), and output flange (4-1) are rotatably connected to the first central profile surface (1-2), the eccentric profile surface (1-3), and the second central profile surface (1-4), respectively. A base (6-1) is fixed to the right end of the rear cover (2-1). The center distance between the two symmetrical arcs on the cross-section of the second annular groove (3-2) is denoted as... 2, 2.

7. The bearing-type differential device according to claim 6, characterized in that, The rear cover (2-1), the intermediate plate (3-1), and the output flange (4-1) are each rotatably connected to the first central profile surface (1-2), the eccentric profile surface (1-3), and the second central profile surface (1-4) via a bearing.

8. The bearing-type differential device according to claim 6, characterized in that, The right end of the input shaft (1-1) has evenly distributed open slots (1-5), and a bushing (7-1) is fixedly connected to the input shaft (1-1). The bushing (7-1) has two free ends.

9. The bearing-type differential device according to claim 6, characterized in that, A first sealing ring mounting groove is formed between the input shaft (1-1) and the rear cover (2-1). The first sealing ring mounting groove is located on the right side of the first bearing. The first sealing ring is installed in the first sealing ring mounting groove. A second sealing ring mounting groove is formed between the output flange (4-1) and the housing (5-1). The second sealing ring mounting groove is located on the left side of the crossed rollers. The second sealing ring is installed in the second sealing ring mounting groove.

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