JP2011217592A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine reducing a cost and suppressing degradation in durability of oil seal.SOLUTION: The rotary electric machine is equipped with: a housing having an opening formed in the end at the side of a load; a rotating shaft 3 with its one portion externally protruded from the inside of the housing through the opening 40; an oil seal 2 arranged at the side of the load of the housing in the outer periphery of the rotating shaft; and an oil seal holding member 1 arranged in the outer periphery of the oil seal with the side opposite to the load being mounted to the end of the load of the housing. A cover 26 is formed in the oil seal holding member to cover the load side of the oil seal so as to prevent a solid material contained in oil from entering the oil seal from a load side of the oil seal and to oppose the end at the side of the rotating shaft to the outer peripheral surface of the rotating shaft through a gap.

Description

  The present invention relates to a rotating electrical machine.

  A rotary electric machine such as an AC servo motor may be used in an environment where oil is scattered. This oil is lubricating oil or the like filled in the reducer to suppress gear wear. In a rotating electrical machine used in such an environment, since oil easily adheres to the load side end, an oil seal is provided between the load side end and the rotating shaft to prevent oil from entering the rotating electrical machine. It is preventing.

  Here, the oil may contain foreign matter (solid matter). For example, when the oil is a lubricating oil filled in the reduction gear, wear powder such as metal powder due to gear wear is mixed in the lubricant. When such solid matter enters the lip portion of the oil seal that comes into contact with the rotating shaft, the wear of the lip portion proceeds and the life of the oil seal is reduced.

  As one technique for suppressing this, a technique of providing an auxiliary lip on the load side of the oil seal has been proposed (for example, see Patent Document 1). By providing the auxiliary lip, it is possible to suppress the solid matter from entering the lip portion of the oil seal, and it is possible to suppress a decrease in the life of the oil seal.

Japanese Utility Model Publication No. 3-54349

  However, the auxiliary lip in the above prior art is a minute part and needs to be brought into contact with the rotating shaft. For this reason, the auxiliary lip is required to have high mounting accuracy and high manufacturing accuracy, and as a result, there is a problem that the cost is increased.

  Therefore, an object of the present invention is to provide a rotating electrical machine capable of suppressing a decrease in the life of an oil seal while suppressing cost.

  In order to solve the above problems, according to one aspect of the present invention, a housing having an opening formed at an end on a load side, and a rotation partially protruding from the inside of the housing through the opening. An oil seal provided on the load side of the housing and on the outer periphery of the rotating shaft; and an oil seal holding provided on the outer periphery of the oil seal, with the non-load side attached to the load side end of the housing A member, and the oil seal holding member covers the load side of the oil seal so as to prevent solids contained in the oil from entering the oil seal from the load side of the oil seal, and A rotating electrical machine is used in which a cover portion is formed in which the end portion on the rotating shaft side is opposed to the outer peripheral surface of the rotating shaft via a gap.

  ADVANTAGE OF THE INVENTION According to this invention, the rotary electric machine which can suppress the fall of the lifetime of an oil seal can be provided, suppressing cost.

1 is a side sectional view of an entire rotating electrical machine according to a first embodiment of the present invention. 1 is an enlarged side sectional view of the vicinity of the oil seal holding member in FIG. Diagram showing oil flow Diagram showing oil flow The sectional side view which expanded the oil seal holding member vicinity of the rotary electric machine which concerns on 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment>
With reference to FIG. 1, the whole structure of the rotary electric machine which concerns on 1st Embodiment of this invention is demonstrated. FIG. 1 is a side sectional view of the entire rotating electrical machine according to the first embodiment. In the present embodiment, an AC servo motor that is a rotating electrical machine will be described as an example.

  In FIG. 1, the rotating electrical machine according to the present embodiment includes an oil seal holding member 1, an oil seal 2, a rotating shaft 3, a load side bracket 4, an anti-load side bracket 5, a load side bearing 6, an anti-load side bearing 7, and a frame. 8, a stator core 9, a bobbin 10, a coil 11, a substrate 12, a resin 13, a magnet 14, a wave washer 15, an encoder 16, and an encoder cover 17. O shown in FIG. 1 is a rotation axis of the rotation shaft 3.

  The coil 11 wound around the bobbin 10 is assembled to the stator core 9 and connected by the substrate 12. Stator core 9, bobbin 10, coil 11, and substrate 12 are molded with resin 13 to form a stator. A frame 8 is attached to the outer periphery of the stator. The load side bracket 4 is attached to the load side of the frame 8, and the anti-load side bracket 5 incorporating the wave washer 15 is attached to the anti-load side.

  A magnet 14 is attached to the outer peripheral surface of the rotating shaft 3. The rotating shaft 3 is attached to the load side bracket 4 and the anti-load side bracket 5 via the load side bearing 6 and the anti-load side bearing 7, and is rotatably supported. The rotating shaft 3 and the magnet 14 form a rotor. An encoder 16 is attached to the anti-load side end of the rotating shaft 3 and the anti-load side of the anti-load side bracket 5. In order to protect the encoder 16, an encoder cover 17 is attached to the anti-load side bracket 5.

  In addition, the load side bracket 4, the anti-load side bracket 5, the frame 8, and the encoder cover 17 described above constitute a housing of the rotating electrical machine.

  The oil seal holding member 1 is provided on the load side end surface of the load side bracket 4 so as to surround the outer periphery of the rotary shaft 3. The oil seal 2 is provided on the outer peripheral surface of the rotary shaft 3 on the load side of the load side bracket 4. The oil seal 2 is provided in a gap between the oil seal holding member 1 and the rotating shaft 3. The oil seal 2 prevents oil from entering from the load side of the oil seal holding member 1 to the anti-load side through the gap.

  The oil seal holding member 1 is filled with grease (lubricating oil for the lip portion) to be described later, and the oil seal 2 is attached to the filled portion, and then attached to the load side end face of the load side bracket 4. It is done. A detailed configuration near the oil seal holding member 1 will be described later.

  Next, the configuration details in the vicinity of the oil seal holding member 1 will be described with reference to FIG. FIG. 2 is an enlarged side sectional view of the vicinity of the oil seal holding member shown in FIG.

  As shown in FIG. 2, a load side bearing 6 is provided between the load side bracket 4 and the rotating shaft 3. An opening 40 is formed in the load side bracket 4 on the load side of the load side bearing 6. The oil seal 2 is provided on the outer peripheral surface of the rotary shaft 3 on the load side of the load side bracket 4. The oil seal holding member 1 covers the outer periphery of the oil seal 2 and is provided on the load side end face of the load side bracket 4. A convex portion 20 is formed on the load side of the oil seal holding member 1. The convex portion 20 is engaged with the opening 40. A hole 21 surrounding the entire outer periphery of the rotary shaft 3 is formed on the inner peripheral side and the anti-load side of the oil seal holding member 1. The oil seal 2 is provided in the gap 18 between the inner peripheral surface of the hole 21 and the outer peripheral surface of the rotary shaft 3. The lip 2 a of the oil seal 2 is in contact with the outer peripheral surface of the rotary shaft 3. Thereby, the oil seal 2 prevents oil from entering the anti-load side (inside the rotating electrical machine) from the load side of the oil seal holding member 1 through the gap 18.

  On the load side of the oil seal holding member 1, a flat portion 22, a peripheral surface portion 23, and an inclined portion 24 are formed. The flat surface portion 22 is a surface perpendicular to the direction of the rotation axis O, and is formed in the oil seal holding member 1 so as to surround the entire outer periphery of the rotation shaft 3. The peripheral surface portion 23 is formed of a surface parallel to the rotation axis O direction, and is formed on the load side and the rotation shaft 3 side with respect to the flat surface portion 22. Further, the peripheral surface portion 23 is formed so as to surround the entire outer periphery of the rotary shaft 3. The inclined portion 24 has an outer peripheral end inclined to the anti-load side with respect to a plane perpendicular to the rotation axis O direction. In other words, the outer peripheral side end of the inclined portion 24 is located on the opposite side of the load from the inner peripheral end. The inclined portion 24 is formed on the load side and the rotating shaft 3 side with respect to the peripheral surface portion 23. The inclined portion 24 is formed so as to surround the entire outer periphery of the rotating shaft 3.

  The circumferential surface portion 23 is formed with a groove portion 25 that opens radially outward. The groove portion 25 is formed so as to surround the entire outer periphery of the rotary shaft 3.

  A cover portion 26 that covers the load side of the oil seal 2 is formed on the inclined portion 24. The rotating shaft side end portion 27 of the cover portion 26 faces the outer peripheral surface of the rotating shaft 3 with a gap G interposed therebetween. The size of the gap G is set to a size that prevents solids such as metal powder contained in the oil from passing through the gap G. For example, the dimension of the gap G is set to be narrower than the outer shape of the solid material. The cover portion 26 configured in this way can prevent solids contained in the oil from entering the load side of the oil seal 2 from the load side of the oil seal holding member 1.

  A concave portion 28 opened to the anti-load side is formed at a portion on the anti-load side of the cover portion 26 and facing the load side of the oil seal 2. The recess 28 is formed so as to surround the entire outer periphery of the rotary shaft 3. Grease 19 is filled between the load side of the oil seal 2 and the non-load side of the cover portion 26.

  As described above, according to the present embodiment, using the oil seal holding member 1 that is larger than the auxiliary lip and does not come into contact with the outer peripheral surface of the rotary shaft 3, the solid matter contained in the oil is removed from the load side of the oil seal 2. The oil seal 2 is prevented from entering. In the example of FIG. 3, the oil seal holding member 1 prevents the solid matter from reaching the lip portion 2 a of the oil seal 2 even if the oil 30 a containing the solid matter adheres to the rotary shaft side end portion 27. ing. Thus, according to the present embodiment, since the oil seal holding member 1 that is larger than the auxiliary lip and does not come into contact with the outer peripheral surface of the rotary shaft 3 is used, the auxiliary lip requires higher mounting accuracy and higher manufacturing accuracy. I can't. For this reason, according to this embodiment, the rotary electric machine which can suppress the fall of the lifetime of an oil seal can be provided, suppressing cost.

  Further, according to the present embodiment, the oil seal 2 is provided in the oil seal holding member 1 in the load side bracket 4 and not on the load side of the load side bearing 6. When the oil seal 2 is provided in the load-side bracket 4 and on the load side of the load-side bearing 6, when replacing the oil seal 2 with reduced sealing performance, the load-side bracket 4 is removed and the load-side bearing is further removed. 6 also needs to be removed. On the other hand, according to the present embodiment, if the oil seal holding member 1 is structured to be detachable from the load side bracket 4 by screw fastening or the like, the oil seal holding can be performed when replacing the oil seal 2 with reduced sealing performance. The member 1 may be removed. Thus, by providing the oil seal 2 on the oil seal holding member 1, the oil seal 2 can be remarkably replaced. Furthermore, when the oil seal 2 is not required for the rotating electrical machine, the oil seal 2 can be removed simply by removing the oil seal holding member 1 from the load side bracket 4.

  Further, according to the present embodiment, the groove portion 25 is formed in the peripheral surface portion 23 of the oil seal holding member 1. For example, it is assumed that the rotating electrical machine is installed so that the rotating shaft 3 faces the horizontal direction as shown in FIG. At this time, when the oil 30b containing solid matter adheres to the flat surface portion 22, the oil 30b flows through the flat surface portion 22 to the rotating shaft 3 side. However, since the oil 30b accumulates in the groove portion 25, it is difficult for the oil 30b to flow to the vicinity of the rotary shaft side end portion 27. Thereby, since it can suppress further that the solid substance contained in oil penetrate | invades into the load side of the oil seal 2, the lifetime reduction of an oil seal can further be suppressed.

  Moreover, according to this embodiment, the groove part 25 is formed so that the outer periphery of the rotating shaft 3 may be enclosed. As a result, the oil 30b accumulated in the groove 25 shown in FIG. 3 flows in the circumferential direction in the groove 25 and drops down below the rotating electrical machine. That is, the solid matter contained in the oil 30 b attached to the flat surface portion 22 does not flow up to the vicinity of the end portion 27 on the rotating shaft side. Thereby, since it can suppress further that the solid substance contained in oil penetrate | invades into the load side of the oil seal 2, the lifetime reduction of an oil seal can further be suppressed.

  Moreover, according to this embodiment, the inclined part 24 is formed in the oil seal holding member 1, and the outer peripheral side end part of the inclined part 24 is located on the opposite side of the load from the inner peripheral side end part. For example, it is assumed that the rotating electrical machine is installed so that the rotating shaft 3 faces the vertical direction as shown in FIG. At this time, when the oil 30 containing solid matter adheres to the inclined portion 24, the oil 30 flows through the inclined portion 24 to the side opposite to the rotating shaft 3. That is, the solid matter contained in the oil 30 attached to the inclined portion 24 does not flow into the rotating shaft side end portion 27. Thereby, since it can suppress further that the solid substance contained in oil penetrate | invades into the load side of the oil seal 2, the lifetime reduction of an oil seal can further be suppressed.

  According to the present embodiment, the inclined portion 24 is formed so as to surround the entire outer periphery of the rotating shaft 3. Therefore, no matter which direction the oil 30 shown in FIG. 4 scatters, as long as it adheres to the inclined portion 24, the attached oil 30 can be prevented from flowing into the rotary shaft side end portion 27.

  Further, according to the present embodiment, the concave portion 28 opened to the anti-load side is formed at a portion on the anti-load side of the cover portion 26 and facing the load side of the oil seal 2. Thereby, the filling operation | work of the (initial) grease 19 at the time of incorporating the oil seal 2 in the oil seal holding member 1 can be made easy, and the lubrication failure by a filling operation | work can be suppressed.

Second Embodiment
With reference to FIG. 5, the structure of the rotary electric machine which concerns on 2nd Embodiment of this invention is demonstrated. FIG. 5 is an enlarged side sectional view of the vicinity of the oil seal holding member. The rotating electrical machine according to the present embodiment is greatly different from the first embodiment in that the oil seal holding member 1 is replaced with the oil seal holding member 1a. Hereinafter, different points will be mainly described. In FIG. 5, the same components as those shown in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 5, the cover portion 26 of the oil seal holding member 1 a is formed with an extending portion 29 extending from the rotation shaft side end portion 27 along the rotation shaft 3 to the load side. The extending portion 29 is formed with a groove portion 31 that opens to the outside in the radial direction. The groove portion 31 is formed so as to surround the entire outer periphery of the rotary shaft 3.

  As described above, according to the present embodiment, the extending portion 29 is formed in the cover portion 26. As a result, the length of the gap G in the direction of the rotation axis O increases. As a result, the solid matter contained in the oil can be further suppressed from entering the load side of the oil seal 2.

  According to the present embodiment, the groove portion 31 is formed in the extended portion 29. For example, it is assumed that the rotating electrical machine is installed so that the rotating shaft 3 faces the horizontal direction as shown in FIG. At this time, when oil containing solid matter adheres to the flat surface portion 22, the peripheral surface portion 23, and the inclined portion 24, the oil flows to the rotating shaft 3 side through these. However, since the oil accumulates in the groove 31, it becomes difficult to flow to the gap G. In this way, it is possible to suppress the solid matter contained in the oil adhering to a wide range of the oil seal holding member 1 from flowing to the gap G.

  Further, according to the present embodiment, the groove 31 is formed so as to surround the entire outer periphery of the rotating shaft 3. Thus, when the rotating electrical machine is installed as shown in FIG. 5, the oil accumulated in the groove portion 31 flows in the circumferential direction in the groove portion 31 and drops down below the rotating electrical machine. That is, it is possible to prevent the solid matter contained in the oil attached to the flat surface portion 22, the peripheral surface portion 23, and the inclined portion 24 from flowing up to the gap G.

  The embodiment of the present invention has been described above. However, a so-called person skilled in the art can appropriately modify the above embodiment without departing from the gist of the present invention, and can appropriately combine the above embodiment and the method according to the modified example. It is. That is, it is needless to say that even a technique with such a change is included in the technical scope of the present invention.

  For example, in the first and second embodiments described above, the inclined portion 24, the groove portions 25, 31, and the concave portion 28 are formed so as to surround the entire outer periphery of the rotating shaft 3. You may form so that the outer periphery of a part may be enclosed.

  In the first and second embodiments described above, the flat portion 22 is formed in the oil seal holding member 1. However, instead of this, the outer peripheral side end is opposite to the plane perpendicular to the rotation axis O direction. An inclined portion inclined toward the load side may be formed.

  In the second embodiment described above, nothing is formed on the peripheral surface portion 23, but the groove portion 25 shown in FIG. 2 may be further formed.

DESCRIPTION OF SYMBOLS 1 Oil seal holding member 2 Oil seal 2a Lip part 3 Rotating shaft 4 Load side bracket 6 Load side bearing 18 Gap 19 Grease 20 Convex part 21 Hole 22 Plane part 23 Peripheral surface part 24 Inclined part 25, 31 Groove part 26 Cover part 27 Rotating shaft Side end 28 Recess 29 Extension portion 40 Opening

Claims (7)

A housing having an opening formed at an end on the load side;
A rotating shaft partially projecting from the interior of the housing through the opening;
An oil seal provided on the outer periphery of the rotating shaft on the load side of the housing;
An oil seal holding member provided on the outer periphery of the oil seal, the anti-load side being attached to the load side end of the housing,
In the oil seal holding member,
The rotating shaft covers the load side of the oil seal so that the solid matter contained in the oil does not enter the oil seal from the load side of the oil seal, and the rotating shaft side end portion passes through the gap to rotate the rotating shaft. A rotating electrical machine in which a cover portion facing the outer peripheral surface of the rotating electrical machine is formed.   The rotating electrical machine according to claim 1, wherein the oil seal holding member is formed with a groove portion that opens radially outward.   The rotating electrical machine according to claim 2, wherein the groove is formed so as to surround the entire outer periphery of the rotating shaft. The oil seal holding member is formed with an extending portion extending from the end portion on the rotating shaft side of the cover portion to the load side along the rotating shaft,
The rotating electrical machine according to claim 1, wherein the groove portion is formed in the extended portion. Between the load side of the oil seal and the anti-load side of the cover part is filled with grease,
5. The rotating electrical machine according to claim 1, wherein a concave portion that opens to the anti-load side is formed at a portion that is on the non-load side of the cover portion and that faces the oil seal.   The rotating electrical machine according to any one of claims 1 to 5, wherein the oil seal holding member is formed with an inclined portion in which a radially outer end is positioned on a more anti-load side than a radially inner end.   The rotating electrical machine according to claim 6, wherein the inclined portion is formed so as to surround the entire outer periphery of the rotating shaft.

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