JP4816162B2 - Oil seal - Google Patents

Description

  The present invention relates to an oil seal provided between a stationary body and a rotating body rotatably attached to the stationary body.

  As an oil seal that prevents leakage of fluids such as oil, a floating ring that can move in a predetermined gap provided between the rotating body and the stationary body is provided, and when the rotating body stops rotating, it comes into contact with the stationary body. There is one provided with a lip seal that closes a predetermined gap (Patent Document 1). In addition, Patent Documents 2 to 5 exist as prior art documents related to the present invention.

JP 2004-132524 A Japanese Utility Model Publication No. 6-14630 JP 2005-147356 A JP-A-8-105550 Japanese Utility Model Publication No. 2-93570

  In the oil seal of Patent Document 1, as the rotational speed of the rotating body increases, the lip seal is displaced in a direction away from the stationary body by centrifugal force, and the stationary body and the lip seal change from the contact state to the non-contact state. This reduces the frictional resistance between the stationary body and the lip seal. However, as the rotational speed of the rotating body increases, the force (adhesion force) that presses the lip seal against the stationary body decreases, which may induce oil leakage particularly during high-speed rotation.

  Then, an object of this invention is to provide the oil seal which can prevent the oil leak accompanying the raise of the rotational speed of a rotary body.

The oil seal of the present invention is an oil seal provided between a rotating body and a stationary body to which the rotating body is rotatably attached and whose internal temperature rises as the rotational speed of the rotating body increases. The outer member is attached to the stationary body and is attached to the rotating body so as to be integrally rotatable, and is combined with the outer member so that a predetermined gap is formed between the outer member and the outer member. The inner member is disposed in the predetermined gap, and is provided in the inner member in a state in which the predetermined gap is closed with a predetermined adhesion force by contacting the outer member when the rotation of the rotating body is stopped. In addition, a movable member that can be displaced in a direction away from the outer member as the rotational speed of the rotating body increases, and a decrease in the predetermined adhesion force that accompanies the displacement of the movable member are compensated. As such, the closure member capable of closing said predetermined gap by changing the properties in accordance with a change in temperature of the interior of the stationary member, in a direction upon receiving the internal pressure of the stationary body closing the predetermined gap The above- described problem is solved by including a pressure receiving portion that biases the blocking member .

Since the inner member and the movable member rotate together with the rotating body when the rotating body rotates, a centrifugal force acting radially outward acts on the movable member. Due to the centrifugal force, the movable member is configured to be displaceable in a direction away from the outer member as the rotational speed of the rotating body increases. Therefore, when the rotational speed of the rotating body increases, the centrifugal force acting on the movable member increases, and the adhesion force that presses the movable member against the outer member decreases. According to this oil seal, the property of the closing member changes according to the temperature change of the stationary body accompanying the increase in the rotational speed of the rotating body, so that the decrease in the adhesion force accompanying the increase in the rotational speed of the rotating body is compensated. . Therefore, in order to suppress the decrease in the adhesion force accompanying the increase in the rotation speed, the adhesion force when the rotation of the rotating body is stopped need not be increased more than necessary. Accordingly, it is possible to effectively prevent oil leakage accompanying an increase in the rotational speed while reducing the frictional resistance at the time of the low rotational speed of the rotating body. In the present invention, the decrease in the adhesion force is compensated for when the decrease in the adhesion force is completely compensated for by the closing member , that is, when the adhesion force is not reduced or when it is not complete, but the adhesion force is reduced. It is a concept that includes any case where is partially supplemented.

Further, since the closure member capable of closing the gap by the Risho constant to changing characteristics depending on temperature changes inside the stationary body is provided, without affecting the operating characteristics of the movable member The closing member can compensate for the decrease in adhesion. That is, the closing member can compensate for the decrease in the adhesion force in a state where the function of the movable member is sufficiently utilized. Further, since the pressure receiving portion that biases the closing member in a direction that closes the predetermined gap by receiving the internal pressure of the stationary body, the closing member closes the predetermined gap by the pressure receiving portion that has received the internal pressure of the stationary body. Therefore, the sealing effect by the closing member is improved.

Closed covering section member can be realized in various aspects. For example, a high thermal expansion member that is disposed in the predetermined gap and has a higher thermal expansion coefficient than at least one of the constituent materials of the outer member and the inner member may be provided as the closing member. Item 2 ). In this case, since the predetermined gap can be closed by the thermal deformation of the high thermal expansion member, it is possible to compensate for the decrease in the adhesion force accompanying the increase in the rotation speed.

Further, as the closing member, a high thermal expansion which is disposed so as to be interposed between the movable member and the outer member and has a higher thermal expansion coefficient than at least one constituent material of the outer member and the inner member. A member may be provided (claim 3 ). In this case, as the temperature inside the stationary body rises, the volume of the high thermal expansion member increases, thereby increasing the radial dimension of the thermal expansion member. When the dimension in the radial direction of the high thermal expansion member increases, the movable member is pushed back outward in the radial direction, and a decrease in adhesion is suppressed. That is, the decrease in the adhesion force accompanying the increase in the rotational speed of the rotating body is compensated by the thermal deformation of the high thermal expansion member.

Further, as the closing member, a bimetal member provided on either the outer member or the inner member so as to be disposed in the predetermined gap and deformable in a direction crossing the predetermined gap is provided. (Claim 4 ). In this case, as the internal temperature of the stationary body rises, the bimetal member can be deformed so as to cross the predetermined gap, thereby closing the predetermined gap. The bimetal member may be provided on either the outer member or the inner member. However, since a heat source is provided on the rotating body side, a temperature gradient is formed inside the stationary body so that the temperature on the rotating body side is high and the temperature decreases as the distance from the rotating body increases until a predetermined time elapses after the temperature rise of the heat source. In such a case, a bimetal member may be provided on the inner member. In this case, since the temperature change on the rotating body side can be detected quickly, the responsiveness of the bimetal member is improved.

As described above, according to the present invention, the property of the closing member changes in accordance with the temperature change of the stationary body accompanying the increase in the rotation speed of the rotation body, so that the adhesion force accompanying the increase in the rotation speed of the rotation body. Therefore, it is not necessary to increase the adhesion force when the rotating body stops rotating more than necessary. Accordingly, it is possible to effectively prevent oil leakage accompanying an increase in the rotational speed while reducing the frictional resistance at the time of the low rotational speed of the rotating body.

(First form)
FIG. 1 is a perspective view showing a main part of an internal combustion engine assembled with an oil seal according to a first embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view of the main part. In FIG. 2, since the oil seal according to the present invention is axially symmetric with respect to the axis CL, only a cross section on one side is shown. Also, unless otherwise noted, only one side cross section is shown for other cross-sectional views. As shown in FIGS. 1 and 2, the crankshaft 101 is attached to the crankcase 100 so as to be rotatable about an axis CL. The oil seal 1A is provided between a crankcase 100 as a stationary body and a crankshaft 101 as a rotating body. That is, the oil seal 1 </ b> A is mounted in an annular gap formed between the crankcase 100 and the crankshaft 101. The oil seal 1A partitions the atmospheric side AS, which is outside the crankcase 100, and the sealed side OS, which is inside the crankcase 100, so that fluid such as oil and blow-by gas leaks from the sealed side OS to the atmospheric side AS. And foreign matter such as dust from the atmosphere side AS to the sealed side OS is prevented. As shown in FIG. 2, the oil seal 1 </ b> A includes an annular outer member 2 and an annular inner member 3 that are provided coaxially with the crankshaft 101. The outer member 2 is attached to the crankcase 100 with an oil seal retainer 103 interposed, and the inner member 3 is attached to the crankshaft 101 so as to be integrally rotatable. The outer member 2 and the inner member 3 are separated and combined so that a gap G is formed between them.

  The outer member 2 has an outer cylindrical portion 21 that is fixed to the oil seal retainer 103 and extends in the direction of the axis CL, and an inward flange portion 22 that extends radially inward from the end of the outer cylindrical portion 21 on the atmosphere side AS. is doing. The inward flange portion 22 includes an upright wall portion 22a that rises radially inward at a substantially right angle with respect to the outer cylindrical portion 21, a side wall portion 22b that extends in the axis CL direction and is substantially parallel to the outer cylindrical portion 21, and a sealing There is an inclined wall portion 22c that is inclined toward the side OS and connects the upright wall portion 22a and the side wall portion 22b. On the other hand, the inner member 3 has an inner cylindrical portion 31 that is fixed to the crankshaft 101 and extends in the direction of the axis CL, and an outward flange portion 32 that extends radially outward from the end of the sealing side OS of the inner cylindrical portion 31. is doing. The outward flange portion 32 is disposed so as to face the inward flange portion 22 of the outer member 2. That is, the outward flange portion 32 rises radially outward at a substantially right angle with respect to the inner cylindrical portion 31, and the inward flange portion 22 extends in the direction of the axis CL following the upright wall portion 32a. A side wall portion 32b substantially parallel to the side wall portion 22b, and an inclined wall portion 32c extending so as to incline toward the atmosphere side AS following the side wall portion 32b and substantially parallel to the inclined wall portion 22c of the inward flange portion 22. I have.

  Of the gap G formed by the outer member 2 and the inner member 3, the gap G1 formed between the side wall portion 22b of the inward flange portion 22 and the side wall portion 32b of the outward flange portion 32 includes a movable member. An annular movable lip 4 is arranged. One end of the sealing side OS is joined to the upright wall portion 32a so that the movable lip 4 can rotate integrally with the inner member 3. The movable lip 4 has an attachment portion 4a attached to the upright wall portion 32a, an intermediate portion 4b extending from the attachment portion 4a toward the atmosphere side AS, and a tip portion 4c following the intermediate portion 4b. The attachment portion 4a is configured to be elastically deformable with a tough metal material such as a spring material. The intermediate portion 4b and the tip portion 4c are made of an elastic body such as rubber and are integrally joined to the mounting portion 4a. An annular garter spring 6 that urges the movable lip 4 radially inward is attached to the distal end portion 4c. When the rotation of the crankshaft 101 is stopped, the movable lip 4 is held in contact with the outer member 2 through the high thermal expansion member 7 as a closing member by the elastic force of the garter spring 6. The high thermal expansion member 7 is provided on the outer member 2 so as to be interposed between the movable lip 4 and the outer member 2. The high thermal expansion member 7 is made of a material having a higher coefficient of thermal expansion than the outer member 2 such as a metal material such as manganese or a resin material.

  As shown in FIG. 2, the gap G formed between the outer member 2 and the inner member 3 is formed between the inclined wall 22 c of the inward flange portion 22 and the inclined wall 32 c of the outward flange portion 32. A floating ring 8 is disposed in the gap G2. The floating ring 8 can move in the gap G2 in a non-contact state with each of the outer member 2 and the inner member 3 while the crankshaft 101 is rotating. In other words, the floating ring 8 has an oil that is present in the gap G2 between the floating ring 8 and the outer member 2 and between the floating ring 8 and the inner member 3, respectively, at a peripheral speed of the inner member 3. Also, it rotates concentrically with the inner member 3 at a slow speed. The thickness dimension of the floating ring 8 is set in consideration of the size of the gap G2 so that a labyrinth seal is formed between the floating ring 8, the outer member 2, and the inner member 3.

  FIG. 3 is an explanatory diagram showing the relationship between the rotational speed of the crankshaft 101 and the force (contact force) pressing the movable lip 4 against the outer member 2. The broken line in FIG. 3 indicates the adhesion force of the comparative example that does not include the high thermal expansion member 7. According to the oil seal 1 </ b> A, when the crankshaft 101 rotates, the inner member 3 rotates integrally with the crankshaft 101, so that centrifugal force acting radially outward acts on the movable lip 4. Since the centrifugal force increases with an increase in the rotational speed of the crankshaft 101, the adhesion force gradually decreases as the rotational speed of the crankshaft 101 increases as shown in FIG. This characteristic is not different between the oil seal 1A and the comparative example. Further, when the rotational speed increases and the centrifugal force increases beyond the limit, the contact force is zero, that is, the movable lip 4 is completely separated from the outer member 2 in the comparative example.

  On the other hand, in the oil seal 1A, when the rotational speed of the crankshaft 101 is increased, the temperature in the crankcase 100 is increased with the increase, and the volume of the high thermal expansion member 7 is increased. When the volume of the high thermal expansion member 7 increases, the radial dimension of the high thermal expansion member 7 increases and the movable lip 4 is pushed back radially outward, as shown by the broken line in FIG. As a result, the contact force gradually increases, and a decrease in the contact force accompanying an increase in the rotational speed of the crankshaft 101 is suppressed. That is, the decrease in the adhesion force is compensated by the change in the volume (property) of the high thermal expansion member 7.

  Such characteristics of the movable lip 4 include various factors such as the outer diameter and spring constant of the garter spring 6 provided on the movable lip 4, the material and dimensions of the mounting portion 4 a of the movable lip 4, and the configuration of the high thermal expansion member 7. It depends on the setting of various factors such as material and radial dimensions. Therefore, the operating characteristics of the movable lip 4 can be adjusted by appropriately setting these elements. For example, as shown in FIG. 3, in order for the movable lip 4 to always close the gap G <b> 1 regardless of the rotational speed of the crankshaft 101, the movable lip 4 is movable as the rotational speed of the crankshaft 101 increases. These elements may be set so that the amount of change in the radial dimension of the high thermal expansion member 7 accompanying the temperature rise is greater than the amount of displacement of the lip 4. By doing so, the movable lip 4 is always pushed back by the high thermal expansion member 7 regardless of the rotational speed of the crankshaft 101, and the gap G1 is maintained closed. Further, when the sealing function by the floating ring 8 is sufficiently exhibited in the normal operation region of the internal combustion engine, the above-described elements are set so that there is a medium speed rotation region in which the movable lip 4 is completely separated from the outer member 2. May be set. In this case, at the time of high-speed rotation in which the rotation speed of the crankshaft 101 further increases beyond the medium-speed rotation region, the high thermal expansion member so that the gap G1 is closed by the high expansion member 7 as the temperature-sensitive seal mechanism. 7 elements are set. As a result, the oil seal 1A can be configured only to ensure sealing performance when the crankshaft 101 rotates at high speed.

According to the above oil seal 1 </ b> A, the decrease in the adhesion force accompanying the increase in the rotational speed of the crankshaft 101 is compensated by the change in the properties of the high thermal expansion member 7. That is, the high thermal expansion member 7 functions as a closing member of the present invention. The oil seal 1A does not need to have an unnecessarily large contact force when the rotation of the crankshaft 101 is stopped. Therefore, the frictional resistance when the crankshaft 101 rotates at a low speed can be reduced, which can contribute to an improvement in fuel consumption. Further, as described above, when the oil seal 1A is designed to ensure only the sealing performance at high speed rotation, the oil seal 1A reduces the frictional resistance in the rotation region other than when the crankshaft 101 is stopped. It effectively functions as a means for preventing oil leakage during high-speed rotation while making use of the characteristics of the movable lip 4.

(Second form)
Next, a second embodiment of the present invention will be described with reference to FIG. This form is different from the first form only in the attachment position of the high thermal expansion member as the closing member, and the other configuration is the same as the first form. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 4, in the oil seal 1 </ b> B of this embodiment, a high thermal expansion member 207 is provided at the distal end portion 4 c of the movable lip 4. Thereby, the high thermal expansion member 207 can exhibit the same effect as the first embodiment. That is, when the temperature in the crankcase 100 rises, the volume of the high thermal expansion member 207 increases and the radial dimension of the high thermal expansion member 207 increases as shown by the broken line in FIG. Thereby, the movable lip 4 is pushed back radially outward. For this reason, the adhesion force gradually increases as the temperature in the crankcase 100 increases, so that a decrease in the adhesion force accompanying an increase in the rotational speed of the crankshaft 101 is suppressed.

(Third form)
Next, a third embodiment of the present invention will be described with reference to FIG. This form is characterized by the configuration of the high thermal expansion member as the closing member. About the same structure as the said form, the same code | symbol is attached | subjected in FIG. 5, and description is abbreviate | omitted. The oil seal 1 </ b> C shown in FIG. 5 is arranged such that the high thermal expansion member 307 is interposed between the outer member 2 and the inner member 3. In the form shown in the drawing, the high thermal expansion member 307 has a gap G3 formed by the side wall portion 22b of the inward flange portion 22 and the inner cylindrical portion 31 among the gap G formed by the outer member 2 and the inner member 3. The inner member 3 is provided so as to be disposed. The constituent material of the high thermal expansion member 307 may be the same as that in the above embodiment. The high thermal expansion member 307 extends in the axis line CL direction, and the dimension in the axis line CL direction is set to a length corresponding to the side wall portion 22b. With the above configuration, when the temperature in the crankcase 100 rises, the volume of the high thermal expansion member 307 increases, and the radial dimension of the high thermal expansion member 307 increases as shown by the broken line in FIG. As a result, the gap G <b> 3 is closed by the high thermal expansion member 307, and the decrease in the adhesion force accompanying the displacement of the movable lip 4 can be compensated.

  The temperature at which the gap G3 is blocked by the high thermal expansion member 307 can be adjusted by appropriately setting various components such as the constituent material and the radial dimension of the high thermal expansion member 307. By such adjustment, the gap G3 can be closed by the high thermal expansion member 307 before the movable lip 4 is separated from the outer member 3, or the high thermal expansion is performed after the movable lip 4 is separated from the outer member 3. The gap G3 can be closed by the member 307. Further, in this embodiment, the dimension in the axis CL direction of the high thermal expansion member 307 can be increased or decreased without any particular restriction, so that the contact area between the high thermal expansion member 307 and the outer member 2 can be easily increased or decreased. Can be adjusted. That is, adjustment of the sealing effect by the high thermal expansion member 307 is facilitated.

  The shape of the high thermal expansion member 307 can be set as appropriate. For example, as shown by the alternate long and short dash line in FIG. 5, the high thermal expansion member 307 may be provided with a pressure receiving portion 307 a formed so as to cross the end of the outer member 3. Thus, when the internal pressure of the crankcase 100 (pressure on the sealing side OS) is higher than atmospheric pressure, the pressure receiving portion 307a receives the internal pressure and is urged in the direction in which the high thermal expansion member 307 closes the gap G3. The adhesion between the high thermal expansion member 307 and the outer member 2 can be improved.

(4th form)
Next, a fourth embodiment of the present invention will be described with reference to FIG. This form is characterized by the configuration of the high thermal expansion member as the closing member. About the same structure as the said form, the same code | symbol is attached | subjected in FIG. 6, and description is abbreviate | omitted. The oil seal 1D shown in FIG. 6 is disposed between the outer member 2 and the inner member 3 so as to cross the gap G3 and extend in the radial direction, and one end in the radial direction is fixed to the outer member 2. And a high thermal expansion member 407 having the other end in the radial direction opened. Further, the inner member 3 of the oil seal 1D is formed with a recess 3a that receives the high thermal expansion member 407 and restrains the high thermal expansion member 407 when the high thermal expansion member 407 is extended by heat. According to this form of the oil seal 1D, as the temperature inside the crankcase 100 rises, the volume of the high thermal expansion member 407 increases and extends. At that time, the high thermal expansion member 407 is inserted into the recess 3a, so that the high thermal expansion member 407 is restrained. Thereby, for example, even when the internal pressure of the crankcase 100 fluctuates while the gap G3 is closed by the high thermal expansion member 407, the high thermal expansion member 407 is restrained by the recess 3a. The gap G3 can be reliably closed.

(5th form)
Next, a fifth embodiment of the present invention will be described with reference to FIG. In this form, the direction of the high thermal expansion member as the closing member is different from the fourth form. About the same structure as the above, the same code | symbol is attached | subjected to FIG. 7, and description is abbreviate | omitted. The oil seal 1E in this form is disposed between the outer member 2 and the inner member 3 so as to cross the gap G3 and extend in the axis CL direction, and one end of the atmosphere side AS is fixed to the outer member 2. And a high thermal expansion member 507 having the other end of the sealed side OS open. In addition, the side wall part 22b of the outer member 2 of this form is extended to the inner member 3 side rather than the said form in consideration of various factors, such as the expansion amount and intensity | strength of the high thermal expansion member 507. According to the oil seal 1E, as the temperature inside the crankcase 100 rises, the volume of the high thermal expansion member 507 increases and extends. Thereby, the tip of the high thermal expansion member 507 can contact the inner member 3 to close the gap G3.

  Also in the case of this form, you may form a recessed part in the inner member 3 similarly to the form of FIG. Further, at least a part of the side wall portion 22b of the inner member 2 may be made of the same material as that of the high thermal expansion member 507, and the side wall portion 22b itself may function as the high thermal expansion member. As a result, the same effects as described above can be exhibited and the number of parts can be reduced.

(Sixth form)
Next, a sixth embodiment of the present invention will be described with reference to FIG. In this embodiment, the structure of the closing member is different from that described above, and the oil seal 1F has a bimetal member 10 as a closing member. About the structure which is common in said form, the same code | symbol is attached | subjected to FIG. 8, and description is abbreviate | omitted. The bimetal member 10 is an annular member formed by combining different kinds of metal materials, and changes its shape from a straight shape to a curved shape by exceeding a set temperature. When the pressure falls below the set pressure, it returns to its original shape. That is, the shape changes from a curved shape to a linear shape. As shown in FIG. 8, the bimetal member 10 is disposed in the gap G <b> 3 so that the end on the atmosphere side AS is fixed to the side wall 22 b of the outer member 2 and the end on the sealing side OS is opened. When the temperature inside the crankcase 100 rises and exceeds the set temperature, the bimetal member 10 is deformed in the direction crossing the gap G3 and radially inward as shown by the broken line in FIG. Contacts the inner member 3, thereby closing the gap G <b> 3.

  When the bimetal member 10 comes into contact with the inner member 3, the outer peripheral surface 11 faces the sealed side OS. When the internal pressure of the crankcase 100 is higher than the atmospheric pressure, the internal pressure acts on the outer peripheral surface 11 of the bimetal member 10, so that the bimetal member 10 receiving the pressure is urged in a direction to close the gap G3. Therefore, since the bimetal member 10 can be pressed against the inner member 3 using the internal pressure of the crankcase 100, the sealing effect by the bimetal member 10 is improved. Thus, the outer peripheral surface 11 of the bimetal member 10 functions as a pressure receiving portion of the present invention.

  Since the bimetal member 10 is an annular member that is continuous in the circumferential direction, the contact force with the inner member 3 hardly changes in the circumferential direction of the inner member 3. That is, the fluctuation of the contact force in the circumferential direction of the inner member 3 can be suppressed. Therefore, according to the oil seal 1F, the uniformity in the circumferential direction of the sealing effect by the bimetal member 10 is improved.

  FIG. 9 is an explanatory diagram for explaining the relationship between the rotational speed of the crankshaft 101 and the amount of oil leakage. The solid line in FIG. 9 indicates the oil seal 1F, and the broken line indicates a comparative example in which the bimetal member 10 is omitted. In the figure, point A indicates the rotational speed at which the contact between the bimetal member 10 and the inner member 3 starts, and point B indicates the rotational speed at which the movable lip 4 starts to move away from the outer member 2. As is clear from this figure, in the case of the comparative example, when the point B is exceeded, the movable lip 4 starts to move away from the outer member 2, and the interval between the movable lip 4 and the outer member 2 increases as the rotational speed increases. Therefore, in the case of the comparative example, the leakage amount gradually increases as the rotational speed increases. On the other hand, in the case of the oil seal 1F, before the movable lip 4 starts to move away from the outer member 2, that is, at the point A, the bimetal member 10 comes into contact with the inner member and the gap G3 is closed. Therefore, even when the rotational speed exceeds the point B and the movable lip 4 is separated from the outer member, oil leakage hardly occurs. Accordingly, the bimetal member 10 compensates for a decrease in the adhesion between the movable lip 4 and the outer member 3 due to an increase in the rotational speed. According to the oil seal 1F, by appropriately adjusting the set temperature of the bimetal member 10, as shown in FIG. 9, the region AR is sealed from the point A to the point B sealed by both the movable lip 4 and the bimetal member 10. Can be provided. Therefore, it is possible to improve the certainty of the sealing effect while reducing the frictional resistance by the movable lip 4.

  The relationship between the rotational speed of the crankshaft 101 and the temperature inside the crankcase 100 differs depending on the form of the internal combustion engine, but in general, when the rotational speed is high, the crankcase 100 has a higher speed than when the rotational speed is low. The internal temperature tends to be high. Therefore, the rotational speed at which the gap G3 is closed by the bimetal member 10 by examining the relationship in advance with respect to the internal combustion engine to which the oil seal 1F is applied and adjusting the set temperature of the bimetal member 10 in consideration of the result. (Point A in FIG. 9) can be set to a desired rotational speed.

(7th form)
Next, a seventh embodiment of the present invention will be described with reference to FIG. The oil seal 1G of this form has the same bimetal member 210 as the form of FIG. However, the direction of the bimetal member 210 is opposite to that in the configuration of FIG. 8, and the bimetal member 210 is attached to the inner member 3. Other than that, the configuration is the same as that described above, and the same reference numerals are given to the same components in FIG. The bimetal member 210 shown in FIG. 10 is disposed in the gap G3 so that the end of the atmosphere side AS is fixed to the inner cylindrical portion 31 of the inner member 3 and the end of the sealing side OS is opened. When the temperature inside the crankcase 100 rises and exceeds the set temperature of the bimetal member 210, the bimetal member 10 is deformed in the direction crossing the gap G3 and radially outward as shown by the broken line in FIG. And the front-end | tip contacts the outer member 2, and the clearance gap G3 is closed by it. Therefore, this form also has the same effect as the sixth form. Moreover, when the bimetal member 210 contacts the outer member 2, the inner peripheral surface 211 of the bimetal member 210 faces the sealed side OS. For this reason, the internal peripheral surface 211 of the bimetal member 210 functions as a pressure receiving part of this invention similarly to the 6th form.

  In general, since the crankshaft 101 of the internal combustion engine is present as a heat source in the crankcase 100, the temperature on the crankshaft 101 side is high until the predetermined time elapses from the temperature rise of the crankshaft 101. A temperature gradient is formed in which the temperature decreases as the distance increases. In the oil seal 1G, since the bimetal member 210 is provided in the inner member 3, it is possible to quickly detect a temperature change on the internal combustion engine side. Therefore, according to the oil seal 1G, the responsiveness of the bimetal member 210 can be improved as compared with the sixth embodiment shown in FIG.

(First reference example )
Next, a first reference example of the present invention will be described with reference to FIGS. About the structure which is common between this reference example and the form mentioned above, the same code | symbol is attached | subjected to these figures, and description is abbreviate | omitted. As shown in these drawings, the oil seal 1H is disposed between the outer peripheral side of the movable lip 4 and the inner member 3, and is provided with a connecting member 12 that couples the movable lip 4 and the inner member 3. . The connecting member 12 is provided as an elastic member such as a coil spring and is made of a shape memory material such as a shape memory alloy or a shape memory resin. Therefore, when the temperature inside the crankcase 100 rises and reaches the set temperature of the connecting member 12, the entire length of the connecting member 12 is extended. Accordingly, the movable lip 4 is urged by the connecting member 12 so as to be pressed against the outer member 2. That is, the connecting member 12 functions as a biasing unit that biases the movable lip 4 in a direction approaching the outer member 2. Thereby, since the displacement of the movable lip 4 with the increase in the rotational speed of the crankshaft 101 is limited by the connecting member 12, it is possible to compensate for the decrease in the adhesion force associated with the displacement. A plurality of such connecting members 12 are provided along the circumferential direction of the movable lip 4 as shown in FIG. The interval between the connecting members 12 may be equal or unequal.

  11 and 12 show a configuration in which the movable lip 4 is urged by the compression reaction force of the connecting member 12, but the movable lip 4 is attached by the tensile force of the connecting member 12 as shown in FIG. It may be a force. The connecting member 12 in FIG. 13 is configured such that the entire length is shortened when the set temperature is exceeded. Thereby, the effect equivalent to FIG.12 and FIG.13 can be exhibited.

( Second reference example )
Next, a second reference example of the present invention will be described with reference to FIG. About the structure which is common between this reference example and the form mentioned above, the same code | symbol is attached | subjected to FIG. 14, and description is abbreviate | omitted. The oil seal 1 </ b> I has a movable lip 904 provided on the inner member 3. The movable lip 904 has a thermoplastic support portion 904 a that supports the movable lip 904 on the inner member 3. The movable lip 904 has the same function as the movable lip 4 described above except that it has the thermoplastic support portion 904a. The thermoplastic support portion 904a is configured such that the elastic modulus increases as the temperature inside the crankcase 100 increases. That is, as the temperature rises, the thermoplastic support portion 904a is cured and changes into a state in which it is difficult to elastically deform. As a result, the displacement of the movable lip 904 accompanying the increase in the rotational speed of the crankshaft 101 is limited by the increase in the elastic modulus of the thermoplastic support portion 904a. It is possible to compensate .

( Third reference example )
Next, a third reference example of the present invention will be described with reference to FIG. About the structure which is common between this reference example and the form mentioned above, the same code | symbol is attached | subjected to FIG. 14, and description is abbreviate | omitted. The oil seal 1J includes an inner member 103 having a high thermal expansion portion 103a. The inner member 103 has a high thermal expansion portion 103a at a position where the movable lip 4 is provided. The high thermal expansion portion 103a is made of a material having a higher coefficient of thermal expansion than other portions of the inner member 103 such as a metal material such as manganese or a resin material. When the temperature inside the crankcase 100 rises, the volume of the high thermal expansion portion 103a increases and deforms to the position indicated by the broken line in FIG. Therefore, as shown by a broken line in FIG. 15, the movable lip 4 is displaced upward in FIG. 15, and the movable lip 4 is pressed against the outer member 2 by the displacement. When the movable lip 4 is pressed against the outer member 2, displacement of the movable lip 4 associated with an increase in the rotational speed of the crankshaft 101, that is, displacement in a direction away from the outer member 2 is prevented. Thereby, the fall of the adhesion force accompanying the displacement comes to be compensated.

  The present invention is not limited to the above embodiments, and can be implemented in various forms within the scope of the gist of the present invention. For example, the application target of the oil seal of the present invention can be applied not only to an internal combustion engine but also to a pump having a stationary body whose internal temperature rises as the rotational speed of the rotating body increases, for example, various pumps. When the oil seal of the present invention is applied to a pump, the oil seal of the present invention may be provided between a pump housing as a stationary body and a pump shaft that is rotatably attached to the pump housing.

The perspective view which shows the principal part which applied the oil seal which concerns on the 1st form of this invention to the internal combustion engine. The cross-sectional schematic diagram which showed the principal part of the oil seal of FIG. Explanatory drawing which showed the relationship between the rotational speed of a crankshaft, and the force (adhesion force) which presses a movable lip to an outer member. The cross-sectional schematic diagram which shows the principal part which applied the oil seal which concerns on the 2nd form of this invention to the internal combustion engine. The cross-sectional schematic diagram which shows the principal part which applied the oil seal which concerns on the 3rd form of this invention to the internal combustion engine. The cross-sectional schematic diagram which shows the principal part which applied the oil seal which concerns on the 4th form of this invention to the internal combustion engine. The cross-sectional schematic diagram which shows the principal part which applied the oil seal which concerns on the 5th form of this invention to the internal combustion engine. The cross-sectional schematic diagram which shows the principal part which applied the oil seal which concerns on the 6th form of this invention to the internal combustion engine. Explanatory drawing explaining the relationship between the rotational speed of a crankshaft, and the amount of oil leaks. The cross-sectional schematic diagram which shows the principal part which applied the oil seal which concerns on the 7th form of this invention to the internal combustion engine. The cross-sectional schematic diagram which shows the principal part which applied the oil seal which concerns on the 1st reference example of this invention to the internal combustion engine. The cross-sectional schematic diagram which showed the connection member vicinity which concerns on the oil seal of FIG. 11 from the axial direction. Explanatory drawing which showed the modification of the 1st reference example . The cross-sectional schematic diagram which shows the principal part which applied the oil seal which concerns on the 2nd reference example of this invention to the internal combustion engine. The cross-sectional schematic diagram which shows the principal part which applied the oil seal which concerns on the 3rd reference example of this invention to the internal combustion engine.

Explanation of symbols

1A to 1J Oil seal 2 Outer member 3, 103 Inner member 4, 904 Movable lip (movable member)
7,207,307,407,507 high thermal expansion member (occlusion material)
10,210 bimetal member (occlusion material)
11 Outer peripheral surface (pressure receiving part)
12 connecting member 103a thermal expansion portion 211 inner peripheral surface (pressure receiving portion)
904a thermoplastic support portion

Claims (4)

An oil seal provided between a rotating body and a stationary body to which the rotating body is rotatably attached and an internal temperature rises as the rotational speed of the rotating body increases,
An outer member attached to the stationary body, an inner member attached to the rotating body so as to be integrally rotatable, and combined with the outer member so as to form a predetermined gap between the outer member and the outer member; The inner member is disposed in the predetermined gap and is in contact with the outer member when the rotation of the rotating body is stopped, and the predetermined gap is closed with a predetermined adhesion force. A movable member that is displaceable in a direction away from the outer member as the rotational speed of the rotating body increases, and a decrease in the predetermined adhesion force that accompanies the displacement of the movable member is compensated . A closing member capable of closing the predetermined gap by changing properties in response to a temperature change; and the closing in a direction of closing the predetermined gap by receiving an internal pressure of the stationary body Oil seal, comprising a pressure receiving portion for urging the timber, the. A high thermal expansion member disposed in the predetermined gap and having a higher thermal expansion coefficient than that of at least one of the outer member and the inner member is provided as the closing member. Item 2. The oil seal according to Item 1 . As the closing member, a high thermal expansion member disposed so as to be interposed between the movable member and the outer member, and having a higher thermal expansion coefficient than at least one constituent material of the outer member and the inner member. The oil seal according to claim 1 , wherein the oil seal is provided. As the closing member, a bimetal member is provided on either the outer member or the inner member so as to be disposed in the predetermined gap and is deformable in a direction crossing the predetermined gap. The oil seal according to claim 1 .

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