Rotation driving device capable of preventing oil seal from falling off

Abstract

The utility model relates to a rotary driving device for preventing an oil seal from falling off, which comprises a base, a gear, a top plate and a threaded end cover, rotating shaft lip-shaped sealing rings are arranged between the base and the threaded end cover, between the base and the gear and between the gear and the top plate, and the base and the top plate are respectively provided with oil seal mounting holes corresponding to the rotating shaft lip-shaped sealing rings. And a groove is outwards formed in the oil seal mounting hole or a boss is inwards formed in the oil seal mounting hole in the radial direction. Due to the fact that the groove is outwards formed in the oil seal installation hole in the radial direction or the boss is inwards formed in the oil seal installation hole in the radial direction, after the oil seal is installed, the oil seal is elastically deformed through pressure self-tightening of working media, the groove is filled with the oil seal in the radial direction or the oil seal is embedded into the inner side of the boss, the oil seal is prevented from being dislocated and falling off, and meanwhile the oil seal and the oil seal installation hole are combined more tightly. And the sealing performance is better.

Description

Technical Field

[0001] The utility model relates to the technical field of rotary drive devices, in particular to a rotary drive device capable of preventing an oil seal from falling off. Background Art

[0002] A slewing drive is a widely used device that uses a slewing bearing as its transmission component. The slewing bearing consists of an inner ring, an outer ring, and balls positioned between the inner and outer rings. In a slewing drive, one ring (either the inner or outer ring) is mounted within a fixed base, while the other ring is connected to a worm, driven by the worm and delivering the worm's driving force. Compared to traditional reduction gears, slewing drives offer a higher reduction ratio, higher load capacity, easier installation and maintenance, and space-saving installation.

[0003] During the manufacturing of rotary drive units, multiple oil seals (rotating shaft lip seals) are typically installed to seal components such as the worm and slewing bearing within the base. While this seals the base cavity against water, the worm and gears within are heavily greased. After the rotary drive reduction gear has operated for a period of time, a pressure differential between the base cavity and the outside world can easily cause the rotating shaft lip seal to misalign and fall out, compromising the unit's sealing performance. While there are commercially available methods to prevent oil seals from falling out by adding retaining rings or outer covers, these are complex structures, require extensive processing, involve complex assembly processes, and are costly. Furthermore, the oil seals have room to move, which can reduce sealing performance and result in poor sealing effectiveness. Utility Model Content

[0004] The purpose of the utility model is to overcome the above-mentioned shortcomings and provide a rotary drive device that prevents the oil seal from falling off, eliminating the need for a retaining ring or an outer cover, simplifying the structure and reducing the cost. By arranging a groove radially outward or a boss radially inward in the oil seal mounting hole, when the oil seal is installed, the pressure of the working medium self-tightens the oil seal to cause elastic deformation, and the oil seal radially fills the groove or embeds into the inner side of the boss, thereby preventing the oil seal from being dislocated and falling off, and making the oil seal more tightly combined with the oil seal mounting hole, thereby improving the sealing performance.

[0005] The purpose of this utility model is achieved in this way:

[0006] A rotary drive device for preventing an oil seal from falling off comprises a base, a gear, a top plate and a threaded end cover. A rotating shaft lip seal ring is provided between the base and the threaded end cover, between the base and the gear, and between the gear and the top plate. The base and the top plate are respectively provided with oil seal mounting holes corresponding to the rotating shaft lip seal rings. A groove is provided radially outward or a boss is provided radially inward in the oil seal mounting hole.

[0007] Preferably, the groove is annular, the groove is connected to the oil seal mounting hole, the inner groove wall of the groove is an arc-shaped guide surface, and the outer groove wall is a vertical anti-slip surface.

[0008] Preferably, the distance between the bottom of the groove and the wall of the oil seal mounting hole is L1, and L1 is 0.3-0.6 mm.

[0009] Preferably, the boss is annular, and the cross section of the boss is a right triangle. The outer side of the boss is provided with a guiding oblique edge facing inward, and the inner side is provided with a vertical right-angled edge.

[0010] Preferably, the distance between the top of the boss and the wall of the oil seal mounting hole is L2, and L2 is 0.3-0.6 mm.

[0011] The beneficial effects of the utility model are:

[0012] By providing a groove radially outward or a boss radially inward in the oil seal mounting hole, when the oil seal is installed, the pressure of the working medium self-tightens the oil seal to elastically deform, and the oil seal radially fills the groove or embeds into the inner side of the boss, thereby preventing the oil seal from being dislocated and falling off, and making the oil seal and the oil seal mounting hole more tightly connected, thereby improving the sealing performance;

[0013] After testing, it was found that after the oil seal mounting hole was provided with a groove or boss, the rotary drive device could well fix the rotating shaft lip seal ring under a pressure of 0-0.6MPa, prevent the oil seal rotating shaft lip seal ring from falling off and maintain the original sealing effect. It is widely used in industries such as engineering machinery, construction machinery, solar photovoltaic, satellite and radar antennas, and medical fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic structural diagram of Example 1 of the present utility model.

[0015] Figure 2 For this utility model Figure 1 side view.

[0016] Figure 3 for Figure 1 A partial enlarged view of point A in the middle.

[0017] Figure 4 for Figure 1 A partial enlarged view of point B in the middle.

[0018] Figure 5 for Figure 2 A partial enlarged view of point C in the middle.

[0019] Figure 6 for Figure 3 Schematic diagram of the structure of the oil seal mounting hole.

[0020] Figure 7 for Figure 4 Schematic diagram of the structure of the oil seal mounting hole.

[0021] Figure 8 for Figure 5 Schematic diagram of the structure of the oil seal mounting hole.

[0022] Figure 9 This is a structural diagram of Example 2 of the present utility model.

[0023] Figure 10 For this utility model Figure 2 side view.

[0024] Figure 11 for Figure 9 A partial enlarged view of point D in the middle.

[0025] Figure 12 for Figure 9 A partial enlarged view of point E in the middle.

[0026] Figure 13 for Figure 10 A partial enlarged view of point F in the middle.

[0027] Figure 14 for Figure 11 Schematic diagram of the structure of the oil seal mounting hole.

[0028] Figure 15 for Figure 12 Schematic diagram of the structure of the oil seal mounting hole.

[0029] Figure 16 for Figure 13 Schematic diagram of the structure of the oil seal mounting hole.

[0030] Wherein: base 1; gear 2; top plate 3; threaded end cover 4; rotating shaft lip seal 5; oil seal mounting hole 6; groove 7; arc-shaped guide surface 7.1; vertical anti-slip surface 7.2; boss 8; guide bevel 8.1; vertical right-angled edge 8.2. DETAILED DESCRIPTION

[0031] Example 1

[0032] See also Figure 1-8 The utility model relates to a rotary drive device for preventing an oil seal from falling off, comprising a base 1, a gear 2, a top plate 3 and a threaded end cover 4. A rotating shaft lip seal 5 is provided between the base 1 and the threaded end cover 4, between the base 1 and the gear 2, and between the gear 2 and the top plate 3. The base 1 and the top plate 3 are respectively provided with oil seal mounting holes 6 corresponding to the rotating shaft lip seal 5, and a groove 7 is provided radially outward of the oil seal mounting hole 6.

[0033] The groove 7 is annular and communicates with the oil seal mounting hole 6 . The inner groove wall of the groove 7 is an arc-shaped guide surface 7 . 1 , and the outer groove wall is a vertical anti-slip surface 7 . 2 .

[0034] The distance between the bottom of the groove 7 and the wall of the oil seal mounting hole is L1, and L1 is 0.3-0.6 mm.

[0035] Working principle:

[0036] When the rotating shaft lip seal 5 is used for dynamic sealing between the base 1 and the threaded end cover 4, between the base 1 and the gear 2, and between the gear 2 and the top plate 3, the rotating shaft lip seal 5 has an interference fit with the oil seal mounting hole. Under the combined action of the working medium pressure (self-tightening), the rotating shaft lip seal 5 produces elastic deformation, and the outer diameter of the rotating shaft lip seal enters the groove along the arc-shaped guide surface, fills the groove, and blocks the gap, so that the rotating shaft lip seal and the oil seal mounting hole are more tightly combined, and the vertical anti-slip surface can better prevent the rotating shaft lip seal from falling off, so that the seal can remain stable under various working conditions and the sealing performance is better.

[0037] Example 2

[0038] See also Figure 9-16 The utility model relates to a rotary drive device for preventing an oil seal from falling off, comprising a base 1, a gear 2, a top plate 3 and a threaded end cover 4. A rotating shaft lip seal 5 is provided between the base 1 and the threaded end cover 4, between the base 1 and the gear 2, and between the gear 2 and the top plate 3. The base 1 and the top plate 3 are respectively provided with oil seal mounting holes 6 corresponding to the rotating shaft lip seal 5, and a boss 8 is radially inwardly provided in the oil seal mounting hole 6.

[0039] The boss 8 is annular in shape, and the cross section of the boss 8 is a right triangle. The outer side of the boss 8 is provided with an inward guiding oblique edge 8.1, and the inner side is provided with a vertical right-angled edge 8.2.

[0040] The distance between the top of the boss 8 and the wall of the oil seal mounting hole is L2, and L2 is 0.3-0.6 mm.

[0041] Working principle:

[0042] When the rotating shaft lip seal 5 is used for dynamic sealing between the base 1 and the threaded end cover 4, between the base 1 and the gear 2, and between the gear 2 and the top plate 3, the rotating shaft lip seal 5 enters the innermost side of the oil seal mounting hole along the guide bevel 8.1, and the rotating shaft lip seal 5 and the oil seal mounting hole are interference fit. Under the combined action of the working medium pressure (self-tightening), the rotating shaft lip seal 5 is elastically deformed, and the rotating shaft lip seal is embedded in the inner side of the boss and fills the inner oil seal mounting hole, blocking the gap, so that the rotating shaft lip seal and the oil seal mounting hole are more tightly combined, and the vertical right-angled edge can better prevent the rotating shaft lip seal from falling off, so that the seal can remain stable under various working conditions and have better sealing performance.

[0043] After testing, it was found that after the groove or boss was set in the oil seal mounting hole, the rotary drive device could well fix the rotating shaft lip seal ring under the pressure of 0-0.6MPa, prevent the oil seal rotating shaft lip seal ring from falling off and maintain the original sealing effect. It is widely used in engineering machinery, construction machinery, solar photovoltaic, satellite and radar antennas, medical fields and other industries.

[0044] In addition to the above embodiments, the present invention also includes other implementation methods. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the scope of protection of the claims of the present invention.

Claims

1. A rotary drive device for preventing an oil seal from falling off, comprising a base, a gear, a top plate, and a threaded end cap, wherein a rotary shaft lip seal is provided between the base and the threaded end cap, between the base and the gear, and between the gear and the top plate, and the base and the top plate are provided with oil seal mounting holes corresponding to the rotary shaft lip seals, respectively. The device is characterized in that: A groove is provided radially outwards or a boss is provided radially inwards on the oil seal mounting hole.

2. A rotary drive device for preventing an oil seal from falling off according to claim 1, characterized in that: The groove is annular and communicates with the oil seal mounting hole. The inner groove wall of the groove is an arc-shaped guide surface, and the outer groove wall is a vertical anti-slip surface.

3. A rotary drive device for preventing an oil seal from falling off according to claim 1 or 2, characterized in that: The distance between the bottom of the groove and the wall of the oil seal mounting hole is L1, and L1 is 0.3-0.6 mm.

4. The rotary drive device for preventing an oil seal from falling off according to claim 1, characterized in that: The boss is annular in shape, and the cross section of the boss is a right-angled triangle. The outer side of the boss is provided with a guiding oblique edge facing inward, and the inner side is provided with a vertical right-angled edge.

5. A rotary drive device for preventing an oil seal from falling off according to claim 1 or 2, characterized in that: The distance between the top of the boss and the wall of the oil seal mounting hole is L2, and L2 is 0.3-0.6 mm.

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