JP3188680U - Oil seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil seal capable of realizing stable oil sealing property and suppressing excessive wear due to foreign matter even when the frequency of switching forward / reverse rotation of a shaft and the frequency of starting / stopping are high. .. SOLUTION: A seal lip 20 of an oil seal has a main seal lip 21 that seals a sealing target and an auxiliary seal lip 22 that is arranged on the sealing target B side of the main sealing lip and removes metallic foreign matter generated from an apparatus. Have. The main seal lip 21 is provided at the top 23 which is in pressure contact with the outer peripheral surface of the rotating shaft, the inclined portion 24 which is provided near the top and is formed on the outside air A side of the top, and is provided near the top and is a sealing target of the top. It has an inclined portion 25 formed on the B side. The inclined portion 24 has both a positive screw portion 26 and a reverse screw portion 27 arranged at angles α and β with respect to the circumferential direction of the main seal lip, respectively. [Selection diagram] Fig. 2

Description

  The present invention relates to an oil seal used for a shaft of a reduction gear or the like mounted on an industrial device.

  For example, as shown in FIG. 5, a conventional oil seal 100 is fitted to a pair of metal rings 110 and 111, an elastic seal lip 120 held by the pair of metal rings, and the seal lip 120. And a garter spring 130. In the oil seal 100 having such a configuration, the top 121 of the seal lip 120 is in contact with the outer peripheral surface of the input shaft (not shown) of the speed reducer, and the oil sucking property of the oil seal in the vicinity of the top 121 is around the input shaft. Of oil is sealed between the speed reducer and the seal lip.

  In recent years, the input shaft of a reduction gear mounted on industrial equipment has been used in various operation patterns due to diversification of applications. In particular, a reduction gear used for an industrial robot has a feature that the frequency of switching the forward / reverse rotation of the input shaft and the frequency of starting / stopping are high. In this case, since the time required for the input shaft to rotate at a constant rotational speed is short, the conventional oil seal cannot sufficiently exhibit the oil suction performance inherent in the seal, and the oil sealing performance becomes unstable. In addition, there is a concern that the main lip may be excessively worn by foreign matters such as metal generated from a device such as a reduction gear.

  The purpose of the present invention is to achieve stable oil sealing even when the frequency of forward / reverse rotation of the shaft and the frequency of start / stop are high, and an oil seal that can suppress excessive wear due to foreign matter Is to provide.

  In order to achieve the above object, an oil seal of the present invention is an oil seal including a metal ring and an elastic seal lip held by the metal ring, and the seal lip seals an object to be sealed. A main seal lip, and an auxiliary seal lip that is disposed on the sealing target side of the main seal and removes foreign matter, the main seal lip being in contact with a shaft that is an adherend, and the vicinity of the top And a first inclined part formed on the outside air side of the top part, and a second inclined part provided in the vicinity of the top part and formed on the sealing target side of the top part, and the first inclined part The portion has both a normal screw portion and a reverse screw portion arranged in the circumferential direction of the main seal lip.

  Preferably, the normal thread portion is arranged in parallel with an angle α (0 <α <90 °) with respect to the circumferential direction of the seal lip, and the reverse thread portion is angled with respect to the circumferential direction of the seal lip. (90 ° <β <180 °).

  Moreover, the said normal thread part has the 1st convex part and 1st recessed part which were alternately arrange | positioned continuously, and the said 2nd convex part and 2nd recessed part by which the said reverse screw part was continuously arranged alternately have.

  Furthermore, it is preferable that a grease composition is enclosed between the second inclined portion and the shaft, and a grease composition is enclosed between the first inclined portion and the shaft.

  Preferably, the seal lip further includes a dust lip disposed on the outside air side with respect to the second inclined portion.

  The oil seal is preferably attached to the shaft of the speed reducer.

  According to the present invention, since both the forward screw portion and the reverse screw portion are arranged on the first inclined portion of the main seal lip, the frequency of switching the forward / reverse rotation of the shaft and the frequency of starting / stopping are high. Even if it exists, the oil suction property which an oil seal originally has can fully be exhibited, and the stable oil sealing property can be implement | achieved. In addition, since the auxiliary seal lip is arranged on the sealing target side of the main seal lip, foreign matter generated from the equipment can be prevented from reaching the main seal lip, and excessive wear of the main seal lip due to foreign matter can be suppressed. It becomes possible to do.

  Further, since the grease composition is enclosed between the second inclined portion and the shaft and the grease composition is also enclosed between the first inclined portion and the shaft, the lubrication of the main seal lip is maintained for a long time. And excessive wear of the main seal lip can be further suppressed.

  Furthermore, the oil seal of the present invention is attached to the shaft of a speed reducer with a high frequency of switching between forward and reverse rotation of the shaft and the frequency of starting and stopping, and can be used as a speed reducer oil seal to reliably achieve the above effects. it can.

It is a fragmentary sectional view showing roughly composition of an oil seal concerning an embodiment of the present invention. It is a partial expanded sectional view of the seal lip in FIG. It is a fragmentary sectional view which shows the state by which the grease composition was apply | coated to the oil seal of FIG. It is a fragmentary sectional view which shows the state in which the oil seal of FIG. 1 was attached to the axis | shaft. It is a fragmentary sectional view which shows the structure of the conventional oil seal.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a partial cross-sectional view schematically showing a configuration of an oil seal according to an embodiment of the present invention. This oil seal is used in various types of equipment, particularly a reduction gear, and is mounted on a shaft for the purpose of sealing a lubricating oil composition or the like (hereinafter referred to as a sealing target) filled in the equipment. Note that the oil seal of FIG. 1 shows an example thereof, and the configuration of the oil seal according to the present invention is not limited to that of FIG.

  The oil seal 1 includes a pair of metal rings 10 and 11, an elastic seal lip 20 held by the pair of metal rings, and a garter spring 30 fitted to the seal lip. The oil seal 1 is a substantially annular member. When a rotating shaft (see FIG. 3) as an adherend is inserted into the annular inner space, the inner peripheral portion of the seal lip 20 is caused by the elastic force of the garter spring 30. Is pressed against the outer peripheral surface of the rotating shaft.

  The metal ring 10 has a cylindrical part 10a and a flange part 10b integrally formed at the end of the cylindrical part on the side of the sealing object B, and its radial cross section is substantially L-shaped. The metal ring 11 has a cylindrical part 11a and a flange part 11b integrally formed at the end of the cylindrical part on the outside air side A. Like the metal ring 10, the radial cross section is substantially L-shaped. It is a type. The metal ring 11 is arranged on the outer peripheral side from the metal ring 10, and is arranged so that the cylindrical part 11a overlaps the cylindrical part 10a in the radial direction. The seal lip 20 is vulcanized and bonded to the pair of metal rings 10 and 11.

  The seal lip 20 includes a main seal lip 21 that seals an object to be sealed, and an auxiliary seal lip 22 that is disposed on the side of the seal object B of the main seal lip and removes metallic foreign matter generated from the device. The seal lip 20 is formed of an elastomer such as synthetic rubber.

  The main seal lip 21 has a substantially V-shaped radial cross section, and its top portion is slidably pressed against the outer peripheral surface of the rotating shaft. Specifically, as shown in FIG. 2, the main seal lip 21 includes a top portion 23 that is in pressure contact with the outer peripheral surface of the rotating shaft, and an inclined portion that is provided near the top portion and is formed on the outside air A side of the top portion 23. 24 (first inclined portion) and an inclined portion 25 (second inclined portion) provided in the vicinity of the top portion 23 and formed on the sealing object B side of the top portion. The inclined portion 25 is formed on the opposite side of the inclined portion 24 with respect to the top portion 23.

  In the present invention, the inclined portion 24 has both a normal screw portion 26 and a reverse screw portion 27 arranged in the circumferential direction of the main seal lip 21. The normal thread portion 26 is arranged in parallel with the circumferential direction of the seal lip 20 at an angle α (0 <α <90 °), and the reverse thread portion 27 is angled β (90 ° with respect to the circumferential direction of the seal lip 20. <Β <180 °). As a result, the oil sucking performance is not impaired and the oil sealing performance is maintained regardless of whether the rotating shaft is rotated forward or backward.

  The forward thread portion 26 includes convex portions 26a (first convex portions) and concave portions 26b (second concave portions) that are alternately arranged. The reverse screw portion 27 includes convex portions 27a (second convex portions) and concave portions 27b. Alternatingly arranged. The pitches of the normal screw portion 26 and the reverse screw portion 27 may be the same or different.

  The auxiliary seal lip 22 is a tongue-like portion disposed inward of the end face of the flange portion 10b, and extends inward (in the direction toward the rotation axis) and toward the sealing object B. When the oil seal 1 is mounted on the rotating shaft, the tip of the auxiliary seal lip 22 contacts or presses against the outer peripheral surface of the rotating shaft. Thereby, the foreign matter generated from the device is removed by the auxiliary seal lip 22.

  The seal lip 20 further includes a dust lip 28 that is disposed on the outside air A side from the inclined portion 24 and removes dust that can enter from the outside (FIG. 1). The dust lip 28 is a tongue-like portion disposed inside the end surface of the flange portion 11b, and extends inwardly (in the direction toward the rotation axis) and toward the outside air A. When the oil seal 1 is attached to the rotating shaft, the tip of the dust lip 28 is disposed in contact with the outer peripheral surface of the rotating shaft or with a minute interval. As a result, dust is removed by the dust strip 28.

  Moreover, in this invention, as shown in FIG. 3, the grease compositions 41 and 42 are apply | coated to the top part 23 and the inclination parts 24 and 25, respectively. As a result, when the oil seal 1 is mounted on the rotating shaft, the grease composition 41 ′ is sealed between the inclined portion 25 and the outer peripheral surface 51 of the rotating shaft 50, as shown in FIG. A grease composition 42 ′ is enclosed between the outer periphery 24 and the outer peripheral surface 51. At this time, the grease composition 41 ′ is filled in a space defined by the inclined portion 25 of the main seal lip 21, the outer peripheral surface 51 of the rotating shaft 50, and the inclined portion 29 of the auxiliary seal lip 22 without any gap. In addition, the grease composition 42 ′ is filled in a space defined by the inclined portion 24 of the main seal lip 21 and the outer peripheral surface 51 of the rotating shaft 50 without any gap. As a result, the top portion 23 is sandwiched between the grease compositions 41 ′ and 42 ′ from both sides, and the grease compositions 41 ′ and 42 ′ are located in the vicinity of the top portion 23 regardless of whether the rotating shaft rotates forward or backward. And the supply of lubricant to the top 23 is maintained.

  The grease compositions 41 and 42 are semi-solid or solid lubricants mainly composed of a base oil, a thickener and additives, and are general grease compositions used for sliding portions between metal and resin. For example, soap grease, non-soap grease, and special grease used in special environments. Examples of the grease composition used in the present invention include “SEALUB S-1” manufactured by NOK Kluber Co., Ltd., in which the base oil is mineral oil and the thickener is lithium soap.

  As described above, according to the present embodiment, since both the normal screw portion 26 and the reverse screw portion 27 are arranged on the inclined portion 24 of the main seal lip 21, the switching frequency of the normal / reverse rotation of the rotary shaft 50. Even when the frequency of starting and stopping is high, the ingress of oil from the outside air A side in the vicinity of the top 23 is ensured. Therefore, the oil sucking property inherent in the oil seal 1 can be sufficiently exhibited, and stable oil sealing property and lubricity can be realized. In addition, since the auxiliary seal lip 22 is disposed on the sealing target B side of the main seal lip 21, it is possible to suppress the metal foreign matter generated from the equipment from reaching the main seal lip 21, and the main seal caused by the metal foreign matter. Excessive wear of the lip 21 can be suppressed.

  Further, a grease composition 41 ′ is enclosed between the inclined portion 25 and the outer peripheral surface 51 of the rotating shaft 50, and a grease composition 42 ′ is also enclosed between the inclined portion 24 and the outer peripheral surface 51 of the rotating shaft 50. Therefore, it is possible to maintain the lubrication of the main seal lip 21, particularly the top 23 serving as the sliding portion, over a long period of time, and it is possible to further suppress excessive wear of the main seal lip 21.

  Particularly, in a reduction gear used for an industrial robot, the frequency of switching the forward / reverse rotation of the input shaft and the frequency of starting / stopping are high, and it may be used continuously for a long time. In such a use environment, the above-described effect can be reliably achieved by attaching the oil seal 1 of the present invention to the input shaft of the reduction gear.

  The oil seal according to the above embodiment has been described above, but the present invention is not limited to the described embodiment, and various modifications and changes can be made based on the technical idea of the present invention.

  For example, in the above embodiment, the oil seal includes a pair of metal rings, but is not limited thereto, and may include a single metal ring. Each metal ring has a substantially L-shaped cross section, but may have another shape such as a U-shape.

  The main seal lip has a substantially V-shaped radial cross section. However, the main seal lip is not limited to this, and may have other shapes as long as it has an end that is slidably pressed on the outer peripheral surface of the rotating shaft. Also good.

  The seal lip of the present invention includes a garter spring, but may not include a garter spring.

  The oil seal of the present invention is suitably used for a reduction gear mounted on various industrial equipment, a motor with a reduction gear, and the like, and is particularly useful as an oil seal for a reduction gear.

DESCRIPTION OF SYMBOLS 1 Oil seal 10,11 A pair of metal ring 10a Tubular part 10b Flange part 11a Tubular part 11b Flange part 20 Seal lip 21 Main seal lip 22 Auxiliary seal lip 23 Top part 24 Inclination part 25 Inclination part 26 Positive thread part 26a Convex part 26b Concave part 27 Reverse thread part 27a Convex part 27b Concave part 28 Dustrip 30 Garter spring 41 Grease composition 42 Grease composition 41 'Grease composition 42' Grease composition 50 Rotating shaft 51 Outer peripheral surface

Claims (6)

An oil seal comprising a metal ring and an elastic seal lip held by the metal ring,
The seal lip includes a main seal lip that seals an object to be sealed, and an auxiliary seal lip that is disposed on the seal target side of the main seal and removes foreign matter.
The main seal lip includes a top portion that comes into contact with a shaft that is an adherend, a first inclined portion that is provided in the vicinity of the top portion and is formed on the outside air side of the top portion, and is provided in the vicinity of the top portion and that has the top portion. And a second inclined portion formed on the sealing target side of
The oil seal according to claim 1, wherein the first inclined portion has both a normal screw portion and a reverse screw portion arranged in a circumferential direction of the main seal lip.   The normal threaded portion is arranged side by side with an angle α (0 <α <90 °) with respect to the circumferential direction of the seal lip, and the reverse threaded portion has an angle β (90 ° with respect to the circumferential direction of the seal lip. The oil seal according to claim 1, wherein the oil seals are arranged side by side at <β <180 °.   The normal screw portion has first convex portions and first concave portions arranged alternately and continuously, and the reverse screw portion has second convex portions and second concave portions arranged alternately and continuously. The oil seal according to claim 1 or 2, characterized by the above.   The oil according to claim 1, wherein a grease composition is enclosed between the second inclined portion and the shaft, and a grease composition is enclosed between the first inclined portion and the shaft. seal.   The oil seal according to claim 1, wherein the seal lip further includes a dust lip disposed on the outside air side with respect to the second inclined portion.   The oil seal according to claim 1, wherein the oil seal is attached to a shaft of a reduction gear.

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