JP5527199B2 - Stirling engine - Google Patents

Description

  The present invention relates to a Stirling engine.

  In recent years, Stirling engines have attracted attention in order to recover exhaust heat and factory exhaust heat of internal combustion engines mounted on vehicles such as passenger cars, buses, and trucks. A technique considered to be related to the present invention is disclosed in Patent Document 1, for example.

JP-A-3-281972

  In a Stirling engine that performs gas lubrication between the piston and the cylinder, the output can be improved by pressurizing the inside of the crankcase. Further, in a Stirling engine that performs gas lubrication between a piston and a cylinder, the output shaft can be provided in a state of extending outside the crankcase. In this case, in order to maintain the pressure in the pressurized crankcase, a shaft seal member for sealing the inside of the crankcase can be provided on the output shaft.

  However, when trying to seal the inside of the crankcase with the shaft seal member, the shaft seal member is usually arranged in the following orientation. That is, it arrange | positions so that the lip part which binds an output shaft among shaft seal members may be exposed inside a crankcase. For this reason, in this case, when the inside of the crankcase is pressurized, the binding force of the shaft seal member is increased. When the shaft seal member has poor oil lubrication or no oil lubrication and the tightening force of the shaft seal member is increased, energy loss due to increased friction occurs. At the same time, the life of the shaft seal member is reduced due to accelerated wear.

  On the other hand, in order to perform oil lubrication of the shaft seal member, for example, it is conceivable to scatter oil to the shaft seal member inside the crankcase. However, in a Stirling engine that performs gas lubrication between the piston and the cylinder, gas lubrication performance is impaired due to the influence of scattered oil, and as a result, the output may be significantly reduced.

  In view of the above problems, the present invention can maintain the pressure in the crankcase and lubricate the shaft seal member in a mode that does not impair the gas lubrication performance when performing gas lubrication between the piston and the cylinder and pressurizing the crankcase. The aim is to provide a possible Stirling engine.

  The present invention is provided with a cylinder, a piston in which gas lubrication is performed between the cylinder, an output shaft that converts the reciprocating motion of the piston into a rotational motion, the output shaft extending outward, and an internal Of the output shaft, a first shaft seal member that is a gas seal provided to a portion of the output shaft that extends to the outside of the crankcase, and the first shaft of the output shaft. A second shaft seal member that is an oil seal provided for a portion on the crankcase side when viewed from the shaft seal member, and the crankcase side when viewed from the first shaft seal member among the output shafts A third shaft seal member that is an oil seal provided on a portion opposite to the first shaft seal member, and is formed between the first shaft seal member and the second shaft seal member. And while a Stirling engine encapsulating oil and a second space formed between the first shaft seal member and the third shaft seal member.

In the first aspect of the present invention, the pressure in the first space is adjusted so that the pressure difference between the pressure in the first space and the pressure in the crankcase is within a first predetermined range. And a second pressure adjustment that adjusts the pressure in the second space so that the pressure difference between the pressure in the second space and the external space is within a second predetermined range. It is preferable that the structure further includes a mechanism.

  Moreover, it is preferable that this invention is a structure further provided with the oil scooping member which scoops up oil in the part provided in the said 1st space among the said output shafts.

  The present invention further includes an oil amount adjusting mechanism for adjusting the amount of oil sealed in the first and second spaces by flowing oil from the second space to the first space. It is preferable that it is the structure which has.

  According to the present invention, when gas lubrication is performed between the piston and the cylinder and the inside of the crankcase is pressurized, the pressure in the crankcase can be maintained, and the shaft seal member can be lubricated in a manner that does not impair the gas lubrication performance.

It is a schematic block diagram of a 1st Stirling engine. It is a figure which shows the principal part of a 1st Stirling engine. It is a figure which shows the principal part of a 2nd Stirling engine. It is a figure which shows the principal part of a 3rd Stirling engine. It is a figure which shows the principal part of a 4th Stirling engine. It is a figure which shows operation | movement of 1st ECU with a flowchart. It is a figure which shows the principal part of a 5th Stirling engine. It is a figure which shows operation | movement of 2nd ECU with a flowchart.

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

  FIG. 1 is a schematic configuration diagram of a Stirling engine 10A which is a first Stirling engine. The Stirling engine 10A is a two-cylinder α-type Stirling engine. The Stirling engine 10A includes a high temperature side cylinder 20 and a low temperature side cylinder 30 which are two cylinders arranged in series and parallel. The high temperature side cylinder 20 includes an expansion piston 21 and a high temperature side cylinder 22, and the low temperature side cylinder 30 includes a compression piston 31 and a low temperature side cylinder 32. The compression piston 31 is provided with a phase difference so as to move with a delay of about 90 ° in crank angle with respect to the expansion piston 21. The reciprocating motion of the pistons 21 and 31 is converted into rotational motion by the output shaft 61.

  The upper space of the high temperature side cylinder 22 is an expansion space. The working fluid heated by the heater 47 flows into the expansion space. The heater 47 is a multi-tube heat exchanger, and performs heat exchange between a circulating working fluid and exhaust gas from an internal combustion engine (not shown). Thus, the working fluid is heated with the thermal energy recovered from the exhaust. The exhaust from the internal combustion engine constitutes a high-temperature heat source for the Stirling engine 10A.

The upper space of the low temperature side cylinder 32 is a compression space. The working fluid cooled by the cooler 45 flows into the compression space. The regenerator 46 exchanges heat with the working fluid reciprocating between the expansion space and the compression space. Specifically, the regenerator 46 receives heat from the working fluid when the working fluid flows from the expansion space to the compression space, and releases the stored heat to the working fluid when the working fluid flows from the compression space to the expansion space. . Air is applied to the working fluid. However, the present invention is not limited to this, and a gas such as He, H ₂ , or N ₂ can be applied to the working fluid.

  Next, the operation of the Stirling engine 10A will be described. When the heater 47 heats the working fluid, the working fluid expands and compresses the expansion piston 21. As a result, the output shaft 61 rotates. Next, when the expansion piston 21 moves up, the working fluid passes through the heater 47 and is transferred to the regenerator 46. Then, heat is released by the regenerator 46 and flows to the cooler 45. The working fluid cooled by the cooler 45 flows into the compression space and is further compressed as the compression piston 31 rises. The working fluid compressed in this way then rises in temperature while taking heat from the regenerator 46 and flows into the heater 47. And it is heated again and expands. The Stirling engine 10A operates through the reciprocating flow of the working fluid.

  In this embodiment, since the heat source of the Stirling engine 10A is the exhaust gas of the internal combustion engine, the amount of heat obtained is limited, and it is necessary to operate the Stirling engine 10A within the range of the obtained heat amount. Therefore, in this embodiment, the internal friction of the Stirling engine 10A is reduced as much as possible. Specifically, gas lubrication is performed between the cylinders 22 and 32 and the pistons 21 and 31 in order to eliminate the friction loss due to the piston ring having the largest friction loss among the internal friction of the Stirling engine 10A.

  In the gas lubrication, the pistons 21 and 31 are made to float in the air by using the pressure (distribution) of air generated by a minute clearance between the cylinders 22 and 32 and the pistons 21 and 31. Since the gas lubrication has an extremely small sliding resistance, the internal friction of the Stirling engine 10A can be greatly reduced. Specifically, for example, static pressure gas lubrication in which a pressurized fluid is ejected and the object is floated by the generated static pressure can be applied to the gas lubrication that floats the object in the air. However, the present invention is not limited to this, and the gas lubrication may be, for example, dynamic pressure gas lubrication.

  In the Stirling engine 10A, the inside of the crankcase 62 is pressurized in order to obtain a larger output. In this regard, when pressurizing the inside of the crankcase 62, the Stirling engine 10A includes a pressurizing pump 51, a pressurizing pipe 52, and a pressurizing on-off valve 53. The pressurizing pump 51 pressurizes the inside of the crankcase 62. The pressurizing pipe 52 connects the pressurizing pump 51 and the crankcase 62. The pressurization on-off valve 53 is provided so as to be interposed in the pressurization pipe 52 and switches between permitting and prohibiting pressurization in the crankcase 62.

  In the Stirling engine 10A, even when the inside of the crankcase 62 is pressurized during operation, the working fluid that exists in the expansion space and the compression space through the minute clearance formed between the pistons 21 and 31 and the cylinders 22 and 32. The average pressure of the working fluid and the average pressure of the working fluid existing in the crankcase 62 are substantially equal with time. For this reason, in the Stirling engine 10A, the working fluid is pressurized by pressurizing the inside of the crankcase 62 so that a larger output can be obtained.

  FIG. 2 is a view showing a main part of the Stirling engine 10A. The Stirling engine 10 </ b> A includes an output shaft 61 and a crankcase 62. Further, a first housing 63 and a second housing 64 are provided. The output shaft 61 is provided so as to extend outside the crankcase 62. The first housing 63 is provided in the crankcase 62. The second housing 64 is provided in the first housing 63.

  The housings 63 and 64 form an internal space that opens on the crankcase 62 side. Further, a wall portion in which a hole for inserting the output shaft 61 is formed is provided on the side opposite to the crankcase 62. The housings 63 and 64 are provided so that a portion of the output shaft 61 extending to the outside of the crankcase 62 is inserted.

  A first shaft seal member 71 is provided on a portion of the output shaft 61 that extends to the outside of the crankcase 62. The first shaft seal member 71 is provided from the crankcase 62 side on the wall portion of the first housing 63 in which a hole through which the output shaft 61 is inserted is formed.

  A second shaft seal member 72 is provided on a portion of the output shaft 61 on the crankcase 62 side as viewed from the first shaft seal member 71. The second shaft seal member 72 is provided from the outside of the crankcase 62 on a wall portion of the crankcase 62 in which a hole through which the output shaft 61 is inserted is formed.

  A third shaft seal member 73 is provided on a portion of the output shaft 61 opposite to the crankcase 62 side when viewed from the first shaft seal member 71. The third shaft seal member 73 is provided from the crankcase 62 side on the wall portion of the second housing 64 in which a hole through which the output shaft 61 is inserted is formed.

  A first space R <b> 1 is formed between the shaft seal members 71 and 72. Specifically, the first space R <b> 1 is defined by the shaft seal members 71 and 72, the output shaft 61, the crankcase 62, and the first housing 63. A second space R <b> 2 is formed between the shaft seal members 71 and 73. Specifically, the second space R2 is defined by the third shaft seal member 73, the output shaft 61, and the housings 63 and 64.

  Oil L is sealed in the spaces R1 and R2. The oil L is a lubricating oil that lubricates each of the shaft seal members 71, 72, 73 provided for the output shaft 61. Specifically, the oil L sealed in the first space R1 lubricates the shaft seal members 71 and 72. Further, the oil L enclosed in the second space R2 lubricates the third shaft seal member 73. A first O-ring 65 that prevents oil leakage from the first space R1 is provided between the crankcase 62 and the first housing 63, and oil leakage from the second space R2 is prevented between the housings 63 and 64. A second O-ring 66 is provided.

  The first shaft seal member 71 is a gas seal, and includes a first lip portion 71 a that binds the output shaft 61. The first shaft seal member 71 is disposed such that the first lip portion 71a is exposed to the first space R1. Thus, the gas is prevented from leaking from the first space R1 to the second space R2.

  The second shaft seal member 72 is an oil seal, and includes a second lip portion 72 a that binds the output shaft 61. The second shaft seal member 72 is disposed such that the second lip portion 72a is exposed to the first space R1. Thus, the oil L is provided to prevent the oil L from leaking into the crankcase 62 from the first space R1.

  The third shaft seal member 73 is an oil seal and includes a third lip portion 73 a that binds the output shaft 61. The third shaft seal member 73 is disposed such that the third lip portion 73a is exposed to the second space R2. Thus, the oil L is provided to prevent leakage from the second space R2 to the external space of the second space R2. Specifically, the external space of the second space R2 is an atmospheric space. The external space may be an internal space of another housing, for example.

  The shaft seal members 72 and 73 that are oil seals are set to have a weaker force to bind the output shaft 61 than the first shaft seal member 71 that is a gas seal. Therefore, in the Stirling engine 10A, when the pressure in the first space R1 is lower than the pressure in the crankcase 62, high-pressure gas can leak from the inside of the crankcase 62 to the first space R1. It has become. On the other hand, between the spaces R1 and R2, high pressure gas is prevented from leaking from the first space R1 to the second space R2. For this reason, between the spaces R1 and R2, the first space R1 is a high-pressure space, and the second space R2 is a low-pressure space.

  The oil level of the oil L sealed in the first space R1 is set at a position higher than the tip of the portion of the second lip portion 72a that contacts the output shaft 61 from the lower side. Further, the first lip portion 71 a is set at a position higher than the tip of the portion that contacts the output shaft 61 from the lower side. The oil level of the oil L sealed in the second space R2 is set at a position higher than the tip of the portion of the third lip portion 73a that contacts the output shaft 61 from the lower side.

  Next, the effect of the Stirling engine 10A will be described. In the Stirling engine 10A, high-pressure gas can leak from the inside of the crankcase 62 to the first space R1, which is a limited space, while the first shaft seal member 71 is released from the first space R1. The high pressure gas is prevented from leaking into the second space R2. In addition, since the oil leakage is prevented between the first space R1 and the inside of the crankcase 62, the sealing performance inside the crankcase 62 can be improved as compared with the case where the high pressure gas is prevented from leaking. Can be improved easily. For this reason, the Stirling engine 10A can maintain the pressure in the crankcase 62.

  In the Stirling engine 10A, the shaft seal members 71, 72, 73 can be lubricated with the oil L enclosed in the spaces R1, R2. At the same time, oil leakage from the first space R1 to the inside of the crankcase 62 can be prevented by the second shaft seal member 72, and oil leakage from the second space R2 to the external space can be prevented by the third shaft seal member 73. . For this reason, the Stirling engine 10A can also lubricate the shaft seal members 71, 72, 73 in a mode that does not impair the gas lubrication performance.

  FIG. 3 is a view showing a main part of a Stirling engine 10B which is a second Stirling engine. The Stirling engine 10B is substantially the same as the Stirling engine 10A except that the Stirling engine 10B further includes a first breather valve 81 and a second breather valve 82. The first breather valve 81 corresponds to a first pressure adjustment mechanism, and the second breather valve 82 corresponds to a second pressure adjustment mechanism.

  The first breather valve 81 is provided for the first space R1. Specifically, the first breather valve 81 is provided in the crankcase 62 so that the inside of the crankcase 62 and the first space R1 can communicate with each other. The first breather valve 81 is opened when the pressure in the first space R1 is higher than the pressure inside the crankcase 62. Thus, the pressure in the first space R1 is released to the inside of the crankcase 62, and the pressure is adjusted between the first space R1 and the inside of the crankcase 62.

  The first breather valve 81 configured as described above is configured so that the magnitude of the differential pressure between the pressure in the first space R1 and the pressure in the crankcase 62 falls within the first predetermined range. The pressure in the space R1 is adjusted. Specifically, when the pressure in the first space R1 is higher than the pressure in the crankcase 62, the magnitude of the pressure difference between the pressure in the first space R1 and the pressure in the crankcase 62 is small. The pressure in the first space R1 is adjusted so that More specifically, the pressure in the first space R1 is adjusted so that the pressure in the first space R1 is equal to the pressure in the crankcase 62.

  The second breather valve 82 is provided for the second space R2. Specifically, the second breather valve 82 is provided in the second housing 64 and is provided so as to allow communication between the external space of the second space R2 and the second space R2. The second breather valve 82 opens when the pressure in the second space R2 is higher than the pressure in the external space. Thus, the pressure in the second space R2 is released to the external space, and the pressure is adjusted between the second space R2 and the external space. Specifically, the pressure in the external space is atmospheric pressure.

  The second breather valve 82 configured as described above has the second space R2 such that the magnitude of the pressure difference between the pressure in the second space R2 and the pressure in the external space falls within the second predetermined range. Adjust the pressure. Specifically, when the pressure in the second space R2 is higher than the pressure in the external space, the second pressure is set so that the differential pressure between the pressure in the second space R2 and the pressure in the external space becomes small. The pressure in the space R2 is adjusted. More specifically, the pressure in the second space R2 is adjusted so that the pressure in the second space R2 is equal to the pressure in the external space. The first predetermined range and the second predetermined range may be the same.

  Next, the effect of the Stirling engine 10B will be described. Here, the temperature of the oil L enclosed in the spaces R1 and R2 increases with the operation of the Stirling engine 10B. As a result, when the pressure in the spaces R1 and R2 increases, the shaft seal members 72 and 73, which are oil seals, cause excessive friction and oil leakage.

  On the other hand, in the Stirling engine 10B, the first breather valve 81 includes the first breather valve 81 so that the differential pressure between the pressure in the first space R1 and the pressure in the crankcase 62 is within the first predetermined range. The pressure in the space R1 is adjusted. In addition, the second breather valve 82 adjusts the pressure in the second space R2 so that the magnitude of the differential pressure between the pressure in the second space R2 and the pressure in the external space is within the second predetermined range. . For this reason, the Stirling engine 10B can function the shaft seal members 72 and 73 more appropriately than the Stirling engine 10A.

  In addition, the Stirling engine 10B adjusts the pressure in the first space R1 so that the pressure in the first space R1 and the pressure in the crankcase 62 become equal, and the pressure in the second space R2 and the pressure in the external space By adjusting the pressure in the second space R2 so that the pressure becomes equal, the shaft seal members 72 and 73 can function more appropriately.

  FIG. 4 is a view showing a main part of a Stirling engine 10C which is a third Stirling engine. The Stirling engine 10C is substantially the same as the Stirling engine 10B except that the setting of the oil level of the oil L enclosed in the spaces R1 and R2 is different and that the scoring plate 85 is further provided. Similar changes may be applied to the Stirling engine 10A, for example.

  In the Stirling engine 10C, the oil level of the oil L sealed in the first space R1 is set at a position lower than the tip of the portion of the second lip portion 72a that contacts the output shaft 61 from the lower side. Yes. At the same time, the oil level of the oil L sealed in the first space R1 is set to a position lower than the tip of the portion of the first lip portion 71a that contacts the output shaft 61 from the lower side. The oil level of the oil L sealed in the second space R2 is set at a position lower than the tip of the portion of the third lip portion 73a that contacts the output shaft 61 from the lower side. The oil level of the oil L sealed in the first space R1 may be set at a position higher than the tip of the portion of the first lip portion 71a that contacts the output shaft 61 from the lower side.

  The scraping plate 85 is provided in a portion of the output shaft 61 that is provided in the first space R1. The scraping plate 85 is a ring-shaped member, and is provided so that the outer peripheral portion reaches a position lower than the oil level of the oil L sealed in the first space R1. The scraping plate 85 corresponds to a scraping member and scrapes up the oil L in the first space R1. The scraping plate 85 may be integrally formed with the output shaft 61.

  Next, the effect of the Stirling engine 10C will be described. Here, when the oil level of the oil L sealed in the first space R1 is set at a position higher than the tip of the portion of the second lip portion 72a that contacts the output shaft 61 from the lower side, There is a possibility that the oil L enclosed in the first space R <b> 1 leaks into the crankcase 62 when the output shaft 61 stops rotating. Similarly, in the case of the second space R2, the oil L enclosed in the second space R2 may leak to the external space.

  On the other hand, in the Stirling engine 10C, the oil level of the oil L sealed in the first space R1 is set to a position lower than the tip of the second lip portion 72a that contacts the output shaft 61 from the lower side. doing. Further, the oil level of the oil L sealed in the second space R2 is set at a position lower than the tip of the portion of the third lip portion 73a that contacts the output shaft 61 from the lower side. For this reason, compared with the Stirling engine 10B, the Stirling engine 10C can further prevent oil leakage when the output shaft 61 stops rotating.

  Further, the Stirling engine 10C can make the oil L reach the shaft seal members 71 and 72 by the scraping plate 85 when the output shaft 61 rotates. At the same time, the oil L can reach the third shaft seal member 73 by allowing the oil L to leak from the first space R1 having a high pressure to the second space R2. For this reason, the Stirling engine 10C can prevent oil leakage when the output shaft 61 stops rotating, and can also ensure lubrication of the shaft seal members 71, 72, 73.

  FIG. 5 is a diagram showing a main part of a Stirling engine 10D which is a fourth Stirling engine. The Stirling engine 10D is substantially the same as the Stirling engine 10C except that an oil amount adjusting mechanism 100A is further provided. Similar changes may be applied to the Stirling engines 10A and 10B, for example.

  The oil amount adjustment mechanism 100A includes an oil transport unit 110 and a drive control unit 120A. The oil transport unit 110 includes an oil pipe 111, an oil pump 112, and a check valve 113. The drive control unit 120A includes a power transmission unit 121, a level sensor 122, and an ECU 125A.

  The oil pipe 111 is provided so as to communicate the spaces R1 and R2. The oil pump 112 is provided so as to be interposed in the oil pipe 111. The oil pump 112 is a mechanical pump, and pumps the oil L sealed in the second space R2 to the first space R1. The check valve 113 is provided so as to be interposed in the oil pipe 111. The check valve 113 is provided in a portion of the oil pipe 111 on the downstream side of the oil pump 112. The check valve 113 allows the oil L to flow from the second space R2 to the first space R1, and prohibits the oil L from flowing from the first space R1 to the second space R2.

  The power transmission unit 121 connects the output shaft 61 and the oil pump 112. The power transmission unit 121 transmits the output of the Stirling engine 10D to the oil pump 112. The power transmission unit 121 includes a clutch 121a. The clutch 121a intermittently transmits the output from the output shaft 61 to the oil pump 112. The level sensor 122 is provided in the second space R2. The level sensor 122 detects the level (amount) of the oil L sealed in the second space R2.

  The ECU 125A is an electronic control device, and the level sensor 122 is electrically connected as sensors and switches. The clutch 121a is electrically connected as a control target. In the ECU 125A, the clutch 121a is connected when the amount of the oil L enclosed in the second space R2 exceeds the first predetermined amount α, and the second predetermined amount smaller than the first predetermined amount α. A control unit that disconnects the clutch 121a when it falls below β is functionally realized. For example, the control unit may be realized such that the clutch 121a is intermittently connected at a predetermined time interval every time a predetermined time elapses.

  The oil amount adjusting mechanism 100A configured as described above adjusts the amount of the oil L enclosed in the spaces R1 and R2 by circulating the oil L from the second space R2 to the first space R1. Specifically, when the amount of the oil L enclosed in the second space R2 exceeds the first predetermined amount α, the oil L is circulated from the second space R2 to the first space R1, When the amount of the oil L enclosed in the second space R2 is less than the second predetermined amount β, by stopping the flow of the oil L from the second space R2 to the first space R1, The amount of oil L enclosed in the spaces R1 and R2 is adjusted.

  Next, the operation of the ECU 125A, which is the operation of the first ECU, will be described using the flowchart shown in FIG. The ECU 125A determines whether or not the amount of the oil L sealed in the second space R2 exceeds the first predetermined amount α (step S1). If the determination is negative, this flowchart is temporarily terminated. On the other hand, if the determination is affirmative, ECU 125A connects clutch 121a (step S2A). As a result, the oil pump 112 is driven. As a result, the oil L flows from the second space R2 to the first space R1.

  Subsequent to step S2A, ECU 125A determines whether or not the amount of oil L sealed in second space R2 has fallen below a second predetermined amount β (step S3). If the determination is negative, this flowchart is temporarily terminated. On the other hand, if the determination is affirmative, the ECU 125A disconnects the clutch 121a (step S4A). Thereby, the oil pump 112 stops. As a result, the circulation of the oil L from the second space R2 to the first space R1 is stopped. After step S4A, this flowchart is temporarily terminated.

  Next, the effect of the Stirling engine 10D will be described. Here, in the Stirling engine 10D, the leakage of the oil L from the first space R1 having a high pressure to the second space R2 is allowed, so that the oil L in the first space R1 gradually decreases, and the first The oil L in the second space R2 gradually increases. As a result, poor lubrication of the shaft seal members 71 and 72 may occur. Further, when the output shaft 61 stops rotating, the oil L may leak to the outside from the second space R2.

  On the other hand, in the Stirling engine 10D, the oil amount adjustment mechanism 100A adjusts the amount of the oil L enclosed in the spaces R1 and R2 by causing the oil L to flow from the second space R2 into the first space R1. To do. Therefore, the Stirling engine 10D can appropriately manage the oil L sealed in the spaces R1 and R2 as compared with the Stirling engine 10C.

  FIG. 7 is a view showing a main part of the Stirling engine 10E. The Stirling engine 10E is substantially the same as the Stirling engine 10D except that an oil adjustment mechanism 100B is provided instead of the oil amount adjustment mechanism 100A. The oil adjustment mechanism 100B may be provided in the Stirling engines 10A, 10B, and 10C, for example.

  The oil adjustment mechanism 100B is substantially the same as the oil adjustment mechanism 100A except that it includes a drive control unit 120B instead of the drive control unit 120A. The drive control unit 120B is substantially the same as the drive control unit 120A except that a drive motor 123 is provided instead of the power transmission unit 121 and an ECU 125B is provided instead of the ECU 125A.

  The drive motor 123 is connected to the oil pump 112. The drive motor 123 drives and stops the oil pump 112. The oil pump 112 and the drive motor 123 may be integrally configured as an electric oil pump, for example. The ECU 125B is substantially the same as the ECU 125A except that the control unit is realized as described below and the drive motor 123 is electrically connected instead of the clutch 121a. In the ECU 125B, when the control unit drives the drive motor 123 when the amount of the oil L enclosed in the second space R2 exceeds the first predetermined amount α, and falls below the second predetermined amount β. This is realized so that the drive motor 123 is stopped.

  Next, the operation of the ECU 125B, which is the operation of the second ECU, will be described using the flowchart shown in FIG. This flowchart is the same as the flowchart shown in FIG. 6 except for the points described below. Following the positive determination in step S1, the ECU 125B drives the drive motor 123 (step S2B). Step S2B is followed by step S3. Further, following the positive determination in step S3, the drive motor 123 is stopped (step S4B). After step S4B, this flowchart is temporarily terminated.

  Next, the effect of the Stirling engine 10E will be described. In the Stirling engine 10E as well as the Stirling engine 10D, the oil amount adjusting mechanism 100B causes the oil L to flow from the second space R2 into the first space R1, so that the amount of the oil L enclosed in the spaces R1 and R2 Adjust. For this reason, the Stirling engine 10E can appropriately manage the oil L enclosed in the spaces R1 and R2, similarly to the Stirling engine 10D.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

  For example, the first pressure adjustment mechanism reduces the pressure in the first space to be lower than the pressure in the crankcase, thereby increasing the difference in pressure between the pressure in the first space and the pressure in the crankcase. The pressure in the first space may be adjusted so as to be within the first predetermined range. In addition, the second pressure adjusting mechanism makes the second space pressure smaller than the external space pressure so that the pressure difference between the second space pressure and the external space pressure is the second pressure. The pressure in the second space may be adjusted so as to be within a predetermined range.

  In these cases, for example, the first pressure adjusting mechanism can suck the gas in the first space, for example, and the second pressure adjusting mechanism can suck the gas in the second space, for example. A simple suction device can be applied.

Stirling engine 10A, 10B, 10C, 10D, 10E
Output shaft 61
Crankcase 62
First shaft seal member 71
Second shaft seal member 72
Third shaft seal member 73

Claims (4)

A cylinder,
A piston that performs gas lubrication with the cylinder;
An output shaft for converting the reciprocating motion of the piston into a rotational motion;
A crankcase that is provided in a state where the output shaft extends to the outside, and the inside is pressurized,
A first shaft seal member that is a gas seal provided for a portion of the output shaft that extends to the outside of the crankcase;
Of the output shaft, a second shaft seal member that is an oil seal provided to a portion on the crankcase side as viewed from the first shaft seal member;
A third shaft seal member that is an oil seal provided on a portion of the output shaft opposite to the crankcase side as viewed from the first shaft seal member;
A first space formed between the first shaft seal member and the second shaft seal member, and formed between the first shaft seal member and the third shaft seal member. A Stirling engine with oil sealed in the second space. The Stirling engine according to claim 1,
A first pressure adjusting mechanism that adjusts the pressure in the first space so that the difference between the pressure in the first space and the pressure in the crankcase is within a first predetermined range. When,
A second pressure adjusting mechanism that adjusts the pressure in the second space so that the pressure difference between the pressure in the second space and the external space is within a second predetermined range; Stirling engine. The Stirling engine according to claim 1 or 2,
A Stirling engine further comprising an oil scooping member that scoops up oil in a portion of the output shaft provided in the first space. A Stirling engine according to any one of claims 1 to 3,
A Stirling engine further provided with an oil amount adjusting mechanism for adjusting the amount of oil sealed in the first and second spaces by flowing oil from the second space to the first space. .

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