JP5545318B2 - Rotating electric machine - Google Patents

Description

  The disclosed embodiment relates to a rotating electrical machine.

  Conventionally, a rotating electrical machine in which a speed reducer is connected to a shaft is known (see, for example, Patent Document 1). Lubricating oil for reducing friction or cooling is enclosed in the gear box of the reduction gear.

JP 2006-281421 A

  However, the above-described prior art has room for further improvement in that when the lubricating oil leaks from the speed reducer, the leaked lubricating oil is prevented from entering the rotating electrical machine through the shaft. It was. Such a problem is a problem that can occur in liquids other than the lubricating oil as well.

  An object of one embodiment is to provide a rotating electrical machine that can prevent liquid from entering.

A rotating electrical machine according to one aspect of an embodiment includes a shaft, a housing, an inner seal member, and an outer seal member. The housing rotatably supports the shaft. The inner seal member seals the gap between the shaft and the housing. The outer seal member is disposed closer to the output side of the shaft than the inner seal member, and seals the gap between the shaft and the housing. The outer seal member includes a main lip portion and a dust lip disposed closer to the inner seal member than the main lip portion, and has higher sealing performance than the inner seal member. The dust lip has a tip portion that protrudes obliquely toward the inner seal member and contacts the shaft.

  According to one aspect of the embodiment, liquid intrusion can be prevented.

FIG. 1 is a diagram illustrating a connection relationship between a motor and a speed reducer according to the present embodiment. FIG. 2 is a schematic sectional side view showing the configuration of the motor according to the present embodiment. FIG. 3 is a schematic diagram of a cross section taken along line AA shown in FIG. FIG. 4 is an enlarged view of a portion H shown in FIG.

  Embodiments of a rotating electrical machine disclosed in the present application will be described below in detail with reference to the accompanying drawings. In the following, an example in which the rotating electrical machine disclosed in the present application is a motor will be described. However, the rotating electrical machine disclosed in the present application may be a generator. In addition, this invention is not limited by embodiment shown below.

  FIG. 1 is a diagram illustrating a connection relationship between a motor and a speed reducer according to the present embodiment. As shown in FIG. 1, the motor 1 according to the present embodiment is a servo motor for a robot, and is provided at a joint portion of the robot.

  The speed reducer 2 is connected to the shaft 11 of the motor 1. The speed reducer 2 is a device that decelerates and outputs the rotation of the shaft 11, and the posture of the robot is changed by the output of the speed reducer 2.

  The speed reducer 2 is, for example, a gear type speed reducer, and a lubricating oil for reducing friction between the gears is enclosed in a gear box in which a plurality of gears are accommodated. When the lubricating oil enclosed in the gear box leaks out of the reduction gear 2, the leaking lubricating oil may enter the motor 1 through the shaft 11.

  In the motor 1 according to the present embodiment, in order to prevent the intrusion of the lubricating oil into the motor 1, a double seal member that seals the gap between the shaft 11 and the housing is provided. Specifically, the motor 1 includes an inner seal member 15 and an outer seal member 16 disposed on the output side of the shaft 11 (the side on which the speed reducer 2 is disposed) with respect to the inner seal member 15.

  Accordingly, in the motor 1 according to the present embodiment, it is assumed that the lubricating oil has entered the inner side of the outer seal member 16 while preventing the lubricating oil leaking from the speed reducer 2 from entering the outer seal member 16. In addition, further intrusion of the lubricating oil can be prevented by the inner seal member 15. Therefore, it is possible to prevent the space inside the inner seal member 15 from being contaminated by the lubricating oil. Note that the rotor, the stator, and the like of the motor 1 are disposed in a space inside the inner seal member 15.

  Moreover, in the motor 1 according to this embodiment, the sealing performance of the outer seal member 16 is made higher than that of the inner seal member 15.

  For this reason, cost can be suppressed compared with the case where a sealing member with high sealing performance is used for both the inner sealing member and the outer sealing member. In general, since a seal member having a lower sealing property is formed to be smaller, the motor 1 is placed in the shaft direction as compared with the case where a member having a higher sealing property is used for both the inner sealing member and the outer sealing member. It can be downsized.

  Further, in the motor 1 according to the present embodiment, since the high sealing performance of the outer seal member 16 prevents the intrusion of the lubricant oil to the inside of the outer seal member 16, the lubricant oil is stronger than the outer seal member 16. Difficult to penetrate inside. Therefore, the inner seal member 15 is not easily deteriorated, and the space between the inner seal member 15 and the outer seal member 16 is cleaned with a relatively low frequency.

  Further, as described above, the lubricating oil is less likely to enter the inside of the outer seal member 16, and even if it enters, the amount thereof is compared with the amount of the lubricating oil that reaches the outer seal member 16 through the shaft 11. Then it is slight. Therefore, even if the sealing performance of the inner seal member 15 is made lower than that of the outer seal member 16, it is possible to sufficiently prevent the lubricating oil from entering the inner side of the inner seal member 15.

  Below, the structure of the motor 1 which concerns on this embodiment is demonstrated more concretely. FIG. 2 is a schematic side sectional view showing the configuration of the motor 1 according to the present embodiment.

  As shown in FIG. 2, the motor 1 according to the present embodiment includes a shaft 11, a housing 12, a stator 13, a rotor 14, an inner seal member 15, an outer seal member 16, and a brake portion 17. Is provided.

  The shaft 11 is rotatably supported by the housing 12, and the speed reducer 2 (see FIG. 1) is connected to the load side, and the brake unit 17 is connected to the non-load side.

  The housing 12 includes a first housing part 21 and a second housing part 22. The first housing portion 21 is a cylindrical member in which the stator 13, the rotor 14, and the brake portion 17 are housed, and supports the shaft 11 via the bearing 101 so as to be rotatable. The second housing portion 22 is a member that is detachably attached to the load-side side wall portion 21 a of the first housing portion 21.

  The stator 13 is fixed to the inner periphery of the first housing part 21. The stator 13 includes a stator core 31 and a stator winding 32. In addition, a rotor 14 is disposed opposite to the inner peripheral side of the stator 13 with a gap. The rotor 14 includes a cylindrical rotor core 41 provided on the outer peripheral surface of the shaft 11 and a plurality of permanent magnets 42 arranged on the outer peripheral side of the rotor core 41, and rotates coaxially with the shaft 11.

  When a current flows through the stator winding 32 of the stator 13, a rotating magnetic field is generated inside the stator 13. The rotor 14 rotates due to the interaction between the rotating magnetic field and the magnetic field generated by the permanent magnet 42 of the rotor 14, and the shaft 11 rotates as the rotor 14 rotates.

  The brake portion 17 is a member that is provided on the opposite load side of the shaft 11 and restricts the rotation of the shaft 11. The brake unit 17 is, for example, a non-excitation operation type electromagnetic brake, and the brake unit 17 includes a brake shoe 71, an armature 72, a coil 73, and a spring 74.

  In such a brake part 17, when a voltage is applied to the coil 73, the armature 72 is magnetically attracted against the spring 74, and the space between the armature 72 and the brake shoe 71 is opened. As a result, the shaft 11 is released from the braking force and becomes rotatable. On the other hand, when the power supply is cut off and a non-excited state is established, the armature 72 is pressed against the brake shoe 71 by the force of the spring 74, and a braking force is generated. Thereby, the shaft 11 will be in the state by which rotation was controlled.

  An opening for inserting the shaft 11 is formed in the side wall portion 21a on the load side of the first housing portion 21, and the bearing 101 is fixed to the inner periphery of the opening.

  An inner seal member 15 is attached to the inner periphery of the opening on the output side of the bearing 101, and the gap between the shaft 11 and the first housing portion 21 is sealed by the inner seal member 15.

  An opening for inserting the shaft 11 is also formed in the second housing part 22 attached to the side wall part 21a of the first housing part 21, and the outer seal member 16 is attached to the inner periphery of the opening. The outer seal member 16 seals the gap between the shaft 11 and the second housing portion 22.

  As described above, the motor 1 according to the present embodiment includes two seal members, that is, the inner seal member 15 and the outer seal member 16 as seal members that seal the gap between the shaft 11 and the housing 12. Thereby, the motor 1 can prevent the lubricating oil leaked from the speed reducer 2 from entering the first housing portion 21 through the shaft 11.

  In the motor 1 according to the present embodiment, the outer seal member 16 is attached to the second housing part 22 that is detachable from the first housing part 21. For this reason, workers and the like have more opportunities to be exposed to the lubricating oil than the inner seal member 15, and can easily replace the outer seal member 16, which is more easily deteriorated than the inner seal member 15.

  In addition, since the second housing part 22 is detachable with respect to the first housing part 21, even when the lubricating oil has entered inside the outer seal member 16, the second housing part 22 can be removed by removing the second housing part 22. Contaminated parts can be easily cleaned.

  The side wall portion 21a of the first housing portion 21 has a concave shape with a central portion protruding toward the inner space side of the first housing portion 21, and the second housing portion 22 is formed in a recessed portion of the side wall portion 21a. It is attached to. At this time, the first housing part 21 and the second housing part 22 are flush with each other on the output side.

  As described above, the load-side side wall portion 21a of the first housing portion 21 is recessed, and the second housing portion 22 is accommodated in the space formed by the recess. In addition, an increase in the width of the motor 1 in the shaft direction can be suppressed.

  The second housing part 22 is fixed to the first housing part 21 with an attaching screw 102, and can be easily removed from the first housing part 21 by removing the attaching screw 102. The second housing part 22 is attached to the first housing part 21 via the O-ring 103. Thereby, foreign matter such as dust enters the inside through the gap between the first housing part 21 and the second housing part 22 or the lubricating oil that has entered inside the outer seal member 16 is in contact with the first housing part 21 and the second housing part 22. 2 It is possible to prevent leakage from the gap with the housing portion 22.

  The inner seal member 15 and the outer seal member 16 are arranged at a predetermined interval. The lubricating oil that has entered inside the outer seal member 16 reaches the space 50 a formed between the inner seal member 15 and the outer seal member 16.

  The motor 1 includes a passage 50b that communicates the space 50a with a space outside the housing 12. The passage 50b communicates with a space outside the housing 12 through a communication hole 50c formed in the first housing portion 21, and the lubricating oil accumulated in the space 50a passes through the passage 50b and the communication hole 50c to the housing. 12 is discharged to the space outside.

  Here, in the motor 1 according to this embodiment, the passage 50 b is formed by the first housing part 21 and the second housing part 22. Specifically, the surface on the side wall 21 a side of the passage 50 b and both side surfaces adjacent to the surface are formed by the first housing portion 21, and the surface on the second housing portion 22 side of the passage 50 b is formed by the second housing portion 22. It is formed. For this reason, even if the lubricating oil enters the space 50a, the inside of the space 50a and the passage 50b can be easily cleaned by removing the second housing portion 22.

  FIG. 2 shows a state where the communication hole 50 c is closed by the screw 104. An operator or the like removes the screw 104 when confirming whether or not the lubricant has entered the space 50a, and confirms whether the lubricant leaks from the communication hole 50c. When the lubricating oil leaks from the communication hole 50c, the operator determines that the lubricating oil has entered the space 50a.

  Here, with reference to FIG. 3, the structure of the space 50a and the channel | path 50b is demonstrated more concretely. FIG. 3 is a schematic diagram of a cross section taken along line AA shown in FIG.

  As shown in FIG. 3, the space 50 a is a substantially annular space that extends concentrically from the shaft 11 with the outer peripheral surface of the shaft 11 as the inner peripheral surface, and the outer diameter thereof is that of the inner seal member 15 and the outer seal member 16. It is formed larger than the outer diameter.

  Thus, in the motor 1 according to the present embodiment, the space 50a is widely formed. For this reason, for example, compared with the case where the outer diameter of the space 50a is formed to be the same as the outer diameter of the outer seal member 16, an increase in the pressure in the space 50a due to the penetration of the lubricating oil can be suppressed. Thereby, even if a large amount of lubricating oil has infiltrated from the outer seal member 16, it is difficult for pressure to be applied to the inner seal member 15, so that damage and deterioration of the inner seal member 15 can be suppressed.

  Further, since the shaft 11 is normally rotating, the lubricating oil that has entered the space 50a is scattered in the radial direction of the shaft 11 and adheres to the vicinity of the outer periphery of the space 50a. In the motor 1 according to the present embodiment, the space 50 a is expanded in the radial direction, and the outer peripheral portion of the space 50 a is located at a location away from the inner seal member 15. Thereby, since it becomes difficult to apply lubricating oil to the inner side sealing member 15, the inner sealing member 15 can be prevented from being stained and deteriorated due to the contamination.

  Next, with reference to FIG. 4, the structure of the inner seal member 15 and the outer seal member 16 will be specifically described. FIG. 4 is an enlarged view of a portion H shown in FIG.

  As shown in FIG. 4, the outer seal member 16 is an annular seal member provided between the second housing portion 22 and the shaft 11. The outer seal member 16 includes a first main body portion 16a and a second main body portion 16b formed of an elastic member such as synthetic rubber, and a coil spring 16c.

  A main lip portion 161 and a dust lip 162 are formed in the first main body portion 16a. The main lip portion 161 has a wedge-shaped stepped surface shape and is pressed against the outer peripheral surface of the shaft 11 by the coil spring 16c, thereby preventing intrusion of liquid such as lubricating oil.

  The dust lip 162 has a shape protruding obliquely toward the space 50a, and abuts the shaft 11 at the tip. The dust lip 162 is disposed closer to the space 50a than the main lip portion 161. The dust lip 162 collects foreign matter such as dust contained in the lubricating oil that has entered the main lip portion 161, thereby collecting the dust lip 162 in the space 50a. Prevents foreign matter from entering.

  The 2nd main-body part 16b is arrange | positioned rather than the main lip part 161 of the 1st main-body part 16a. An auxiliary lip portion 163 is formed on the second main body portion 16b. The auxiliary lip portion 163 has a shape that projects obliquely toward the output side (the speed reducer 2 side), and abuts on the shaft 11 at the tip portion. The auxiliary lip portion 163 prevents intrusion of lubricating oil and prevents intrusion of dust and the like from the outside.

  As described above, the outer seal member 16 includes the three lip portions of the main lip portion 161, the dust lip 162, and the auxiliary lip portion 163, and these lip portions strongly prevent the intrusion of the lubricating oil and the intrusion of foreign matters.

  For this reason, even if there is a possibility that the lubricating oil may enter the inside of the outer seal member 16, the frequency thereof is small, and the amount of the lubricating oil to enter is small. Therefore, the inner seal member 15 is not required to have the same sealing performance as the outer seal member 16. For this reason, a seal member having lower sealing performance than the outer seal member 16 is used as the inner seal member 15.

  For example, as shown in FIG. 4, the inner seal member 15 includes a main body 15a formed of an elastic member such as synthetic rubber, and a coil spring 15b. A main lip portion 151 is formed on the main body portion 15 a of the inner seal member 15. The main lip portion 151 has a wedge-shaped stepped surface shape like the main lip portion 161 in the outer seal member 16, and is prevented from entering the lubricating oil by being pressed against the outer peripheral surface of the shaft 11 by the coil spring 15b. To do.

  Thus, as the inner seal member 15, for example, a seal member having a smaller number of lip portions than the outer seal member 16 can be used. On the other hand, since the outer seal member 16 has more lip portions than the inner seal member 15, it is possible to more reliably prevent the intrusion of lubricating oil and the entry of foreign matter compared to the inner seal member 15. It is. The inner seal member 15 may be a seal member including a main lip portion and a dust lip.

  Further, as shown in FIG. 4, the inner seal member 15 is smaller than the outer seal member 16. Specifically, the width L1 of the inner seal member 15 in the shaft 11 direction is smaller than the width L2 of the outer seal member 16 in the shaft 11 direction, and the width h1 of the inner seal member 15 in the radial direction of the shaft 11 is also The outer seal member 16 is smaller than the width h <b> 2 in the radial direction of the shaft 11.

  As described above, a seal member that is smaller than the outer seal member 16 may be used as the inner seal member 15 having a lower sealing performance than the outer seal member 16.

  Further, a seal member provided with a coil spring whose pressing force is weaker than that of the coil spring 16 c of the outer seal member 16 may be used as the inner seal member 15. This is because the sealing performance of the main lip portion becomes lower as the pressing force of the coil spring is weaker.

  The width L3 of the second housing portion 22 in the shaft direction is substantially the same as the width L2 of the outer seal member 16 in the shaft direction, and the fitting portion 22a for attaching the outer seal member 16 is provided on the outer seal member 16. It protrudes from the width L2 in the shaft direction and is provided on the space 50a side. Further, the side wall portion 21 a of the first housing portion 21 has a shape in which a portion facing the fitting portion 22 a is recessed toward the space inside the first housing portion 21.

  In this way, by causing the fitting portion 22a for attaching the outer seal member 16 to protrude toward the space 50a, the side wall portion 21a facing the fitting portion 22a is recessed by the amount that the fitting portion 22a protrudes. The width of the motor 1 in the shaft direction can be further reduced.

  As described above, the motor 1 according to this embodiment includes the shaft 11, the housing 12, the inner seal member 15, and the outer seal member 16. The housing 12 supports the shaft 11 rotatably. The inner seal member 15 seals the gap between the shaft 11 and the housing 12. The outer seal member 16 is disposed closer to the output side of the shaft 11 than the inner seal member 15 and seals the gap between the shaft 11 and the housing 12. Further, the outer seal member 16 has a higher sealing performance than the inner seal member 15.

  Therefore, according to the motor 1 according to the present embodiment, the intrusion of liquid such as lubricating oil can be prevented.

  In the embodiment described above, an example in which the speed reducer 2 is connected to the motor 1 has been described. However, the speed reducer 2 is not necessarily connected to the motor 1. In the embodiment described above, the example in which the infiltration of the lubricating oil is prevented by the inner seal member 15 and the outer seal member 16 has been described. However, the inner seal member 15 and the outer seal member 16 are, for example, cutting oil or the like. It is also possible to prevent the intrusion of liquids other than lubricating oil such as machine oil or water.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

DESCRIPTION OF SYMBOLS 1 Motor 11 Shaft 12 Housing 21 1st housing part 22 2nd housing part 13 Stator 14 Rotor 15 Inner seal member 16 Outer seal member 50a Space 50b Passage 2 Reduction gear

Claims (4)

A shaft,
A housing for rotatably supporting the shaft;
An inner seal member for sealing a gap between the shaft and the housing;
An outer seal member that is disposed on the output side of the shaft with respect to the inner seal member and seals a gap between the shaft and the housing;
Wherein the outer sealing member, and the main lip portion, the main lip portion than and a dust lip which is arranged in the inner seal member side, and the rather high sealability than the inner sealing member,
The duster has a tip portion that protrudes obliquely toward the inner seal member and contacts the shaft . The housing is
A first housing part to which the inner seal member is attached;
A second housing part to which the outer seal member is attached,
The rotating electrical machine according to claim 1, wherein the second housing part is detachable from the first housing part. The first housing portion and the second housing portion form a passage that communicates a substantially annular space formed between the outer seal member and the inner seal member and a space outside the housing. The rotating electrical machine according to claim 2. The substantially annular space is
The rotating electrical machine according to claim 3, wherein an outer diameter is formed larger than that of the outer seal member and the inner seal member.

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