JP2014202166A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive compressor having a hypocycloid mechanism and enabling the number of components thereof to be reduced.SOLUTION: The compressor includes: a crankshaft (10); a bearing (12); a case (20); an outer ring gear (30) arranged so as to surround the crank shaft (10); a planetary gear (42) the pitch circle of which has a radius set to a 1/2 of a radius of a pitch circle of the outer ring gear (30) and in which the crank shaft (10) is inserted so that the planetary gear (42) is rotated relatively to the crank shaft (10); a piston (50) which is connected to the planetary gear (42) so as to rotate relatively to the planetary gear (42) and which reciprocates in the case (20) along a direction parallel to a radial direction of the outer ring gear (30) by rotation of the planetary gear (42) in the outer ring gear (30) while the planetary gear (42) engages with the outer ring gear (30); and a pump (60) for supplying lubrication oil to the bearing (12), wherein the pump (60) is housed in the case (20).

Description

  The present invention relates to a compressor.

  Conventionally, a compressor having a so-called hypocycloid mechanism having an outer ring gear and a planetary gear is known. For example, Patent Document 1 discloses a crankshaft that is rotationally driven by a motor, a case that accommodates the crankshaft, an outer ring gear that is disposed so as to surround the crankshaft, and an inner ring of the outer ring gear that meshes with the inner teeth of the outer ring gear. A compressor is disclosed that includes a planetary gear that rotates and a piston that is connected to the planetary gear so as to rotate relative to the planetary gear. The planetary gear is inserted through the crankshaft so as to rotate relative to the crankshaft. The radius of the pitch circle of the planetary gear is set to one half of the radius of the pitch circle of the outer ring gear. The case includes a cylinder having a shape extending linearly along a direction parallel to the radial direction of the outer ring gear, and a piston is accommodated in the cylinder. In addition, the meshing point of the outer ring gear and the planetary gear when the piston is located at the top dead center in the cylinder coincides with the point on the side closer to the piston at the intersection of the pitch circle of the outer ring gear and the longitudinal direction of the cylinder. Set to do. For this reason, when the planetary gear rotates in the outer ring gear (revolves around the center of the outer ring gear) while meshing with the outer ring gear in accordance with the rotation of the crankshaft, the piston linearly moves along the longitudinal direction of the cylinder in the cylinder. Reciprocate. Here, the cylinder has a shape that guides the piston in the longitudinal direction while maintaining the posture at the top dead center of the piston, that is, the piston is aligned along the longitudinal direction without being inclined with respect to the longitudinal direction of the cylinder. Therefore, when the planetary gear revolves around the outer ring gear while rotating, the piston reciprocates while maintaining the same posture in the cylinder. That is, in this compressor, the rotational motion of the planetary gear driven to revolve in the outer ring gear by the crankshaft is converted into the linear reciprocating motion of the piston.

JP 60-144594 A

  Usually, a compressor as described in Patent Document 1 has a bearing that receives a crankshaft, and lubricating oil is supplied to the bearing by a pump. And when lubricating oil is supplied with a pump with respect to a bearing, lubricating oil may leak from a pump. In this case, an oil receiver for receiving the lubricating oil leaked from the pump is required, which increases costs and increases the number of parts. In order to omit the oil receiver, a high-performance pump excellent in the sealing performance of the lubricating oil is required, and in this case, the cost is high.

  An object of the present invention is to provide a compressor having a hypocycloid mechanism and capable of reducing the number of parts at low cost.

  In order to solve the above-described problems, the present invention provides a crankshaft that is rotationally driven by a prime mover, a bearing that receives the crankshaft, a case that houses the crankshaft and the bearing, and a crankshaft within the case. The outer ring gear arranged so as to surround the pitch circle and the radius of the pitch circle are set to one half of the radius of the pitch circle of the outer ring gear, and the crankshaft is rotated relative to the crankshaft. The planetary gear to be inserted is connected to the planetary gear so as to rotate relative to the planetary gear, and the planetary gear rotates in the outer ring gear while meshing with the outer ring gear, whereby the inside of the case is A piston that reciprocates along a direction parallel to the radial direction of the outer ring gear, and a pump that supplies lubricating oil to the bearing. Providing a compressor that is accommodated in the case.

  According to the present invention, since the pump is accommodated in the case, even when the lubricating oil leaks from the pump when the lubricating oil is supplied to the bearing, the lubricating oil remains in the case and is outside the case. There is no leakage. Therefore, there is no need to add parts such as an oil receiver that receives the lubricating oil leaked from the pump, and the leakage of lubricating oil from the pump is allowed, so a high-performance pump with excellent lubricating oil sealing performance can be obtained. There is no need to use it. In addition, the compressor of the present invention includes a so-called hypocycloid mechanism having an outer ring gear and a planetary gear, so there is no severe lubrication condition as in a compressor using a piston crank mechanism having a crosshead, and the crank Since the rotational motion of the shaft is directly converted into the reciprocating motion of the piston, the power transmission efficiency is superior to a compressor using a piston crank mechanism.

  In this case, it is preferable that the crankshaft and the pump are connected so that the pump is driven by the rotation of the crankshaft.

  In this way, since the prime mover that is the power source for rotating the crankshaft is also used as the power source for the pump, a dedicated power source for driving the pump becomes unnecessary, and the structure is simplified.

  In the present invention, it is preferable that an oil buffer is formed between an attachment wall to which the pump is attached and the crankshaft.

  If it does in this way, lubricating oil can fully be supplied to a bearing etc.

  As described above, according to the present invention, it is possible to provide a compressor that has a hypocycloid mechanism and can reduce the number of parts at low cost.

It is sectional drawing which shows the outline of the structure of the compressor of 1st embodiment of this invention. It is sectional drawing in the II-II line | wire of FIG. It is sectional drawing of the state which looked at the compressor of FIG. 1 from a different angle. It is sectional drawing which shows the vicinity of the attachment wall of the compressor of 2nd embodiment of this invention.

(First embodiment)
A compressor according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

  As shown in FIGS. 1 to 3, the compressor of the present embodiment is disposed in the case 20, the crankshaft 10 that is rotationally driven by the prime mover, the bearing 12 that receives the crankshaft 10, the case 20, and the case 20. A planetary member (planet carrier) 40 having an outer ring gear 30 and a planetary gear 42 meshing with the inner teeth 32 of the outer ring gear 30, and reciprocating along the specific reciprocating direction in the case 20 while rotating relative to the planetary member 40. A moving piston 50 and a pump 60 for supplying lubricating oil to the bearing 12 and each gear are provided. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, but the planetary gear 42 is virtually shown in FIG. Further, in FIG. 2, the pitch circle P of the planetary gear 42 is indicated by a one-dot chain line.

  As shown in FIGS. 1 and 3, the crankshaft 10 has a main shaft 10a connected to the prime mover and a central axis O2 extending in a direction parallel to the central axis O1 at a position deviated from the central axis O1 of the main shaft 10a. And a crank arm 10c that connects the main shaft 10a and the crank pin 10b.

  As shown in FIGS. 1 and 2, the case 20 includes a crankcase 21 that mainly accommodates the crankshaft 10 and a cylinder 28 that accommodates the piston 50. Note that the drawing of a suction line for sucking a gas such as hydrogen gas into the cylinder 28 and the drawing line for discharging the gas compressed in the cylinder 28 to the outside of the cylinder 28 are omitted.

  The crankcase 21 houses the crankshaft 10, the bearing 12, the outer ring gear 30, the planetary member 40, a part of the piston 50, and the pump 60. More specifically, the crankcase 21 includes a main body portion 22 that accommodates a part of the crankshaft 10, the bearing 12, the outer ring gear 30, the planetary member 40, and the piston 50, and a pump housing portion 25 that houses the pump 60. Have. As shown in FIGS. 1 and 3, the pump housing portion 25 is adjacent to the main body portion 22 in the direction of the central axis O1 of the main shaft 10a. An attachment wall 26 for attaching the pump 60 is provided at the boundary between the main body portion 22 and the pump housing portion 25 in the crankcase 21. An oil buffer 27 that holds the lubricating oil pumped up from the pump 60 is formed in a space surrounded by the mounting wall 26, the main body 22, and the crankshaft 10. In the present embodiment, the crankcase 21 has airtightness and pressure resistance, more specifically, pressure resistance that can withstand a pressure comparable to the pressure of the gas sucked from the suction line.

  As shown in FIGS. 1 and 3, the main body 22 includes a first wall 23 that holds the crank arm 10c on the side close to the main shaft 10a and a second wall 24 that holds the crank arm 10c on the side far from the main shaft 10a. And have. The first wall 23 has a first opening penetrating in the direction of the central axis O1, and the main shaft 10a, the bearing 12 near the main shaft 10a, and the crank arm 10c are held in the first opening. The second wall 24 has a second opening penetrating in the direction of the central axis O1, and the bearing 12 and the crank arm 10c far from the main shaft 10a are held in the second opening. The first wall 23 and the second wall 24 are arranged so as to face each other in a posture orthogonal to the central axis O1. The attachment wall 26 is attached to the outer surface of the second wall 24 so as to close the second opening of the second wall 24. As shown in FIG. 3, the lower end 24 a of the second wall 24 is separated from the bottom wall of the crankcase 21, whereby the inside of the main body portion 22 is connected to the inside of the pump housing portion 25. Therefore, the lubricating oil that has been supplied to the bearings and the gears and then dropped to the lower portion of the main body portion 22 is guided to the pump housing portion 25. That is, the lower part of the main body part 22 and the lower part of the pump housing part 25 function as an oil reservoir. The pump housing portion 25 has a shape surrounding the pump 60 together with the mounting wall 26. The inner surface of the bottom wall of the pump housing part 25 is set at a position lower than the inner surface of the bottom wall of the main body part 22.

  As shown in FIG. 1, the cylinder 28 extends linearly in a horizontal plane along a direction parallel to the radial direction of a circle centered on the central axis O <b> 1 of the outer ring gear 30. The cylinder 28 guides the reciprocating motion of the piston 50 along the parallel direction (reciprocating direction).

  As shown in FIGS. 1 and 3, the bearing 12 is provided between the crankshaft 10 and the crankcase 21, more specifically, between the crank arm 10 c and the main body 22. In addition, a first bearing 14 is provided between the crankshaft 10 and the planetary member 40 to allow relative rotation of the planetary member 40 with respect to the crankpin 10b, and between the planetary member 40 and the piston 50, A second bearing 16 for allowing relative rotation of the piston 50 with respect to the planetary member 40 is provided.

  The outer ring gear 30 is an internal gear having internal teeth 32. As shown in FIG. 3, the outer ring gear 30 has a radius larger than the rotation radius of the crank pin 10 b and is disposed in the main body 22 of the crankcase 21 so as to surround the crankshaft 10. More specifically, the outer ring gear 30 is attached to the inner surface of the second wall 24 of the main body 22 in a posture in which the center thereof coincides with the central axis O1 of the main shaft 10a of the crankshaft 10.

  The planetary member 40 includes a planetary gear 42 that meshes with the outer ring gear 30, an eccentric shaft 44 connected to the planetary gear 42, and a counterweight 46 connected to the eccentric shaft 44. As shown in FIGS. 1 and 3, the planetary gear 42, the eccentric shaft 44, and the counterweight 46 are connected to each other in this order in the direction of the central axis O1 of the main shaft 10a so as to rotate integrally. The planetary member 40 is inserted through the crankpin 10b of the crankshaft 10 so as to rotate relative to the crankshaft 10.

  The planetary gear 42 rotates (revolves around the central axis O1) in the outer ring gear 30 while meshing with the outer ring gear 30 as the crank pin 10b of the crankshaft 10 rotates about the central axis O1. The radius of the pitch circle P (see FIG. 2) of the planetary gear 42 is set to one half of the radius of the pitch circle of the outer ring gear 30. Here, the engagement point between the outer ring gear 30 and the planetary gear 42 in a state where the piston 50 is at the top dead center in the cylinder 28 (hereinafter referred to as “top dead center engagement point P1”) is the pitch circle of the outer ring gear 30. Is set so as to coincide with a point on the side closer to the piston 50 in the intersection of the cylinder 28 with the longitudinal direction. Since the radius of the pitch circle P of the planetary gear 42 is half that of the outer ring gear 30, the top dead center meshing point P1 is the longitudinal direction of the cylinder 28 as the planetary gear 42 rotates, that is, The reciprocating movement is repeated linearly along the reciprocating direction.

  As shown in FIGS. 1 and 3, the eccentric shaft 44 has a planetary gear 42 in the direction of the central axis O1 so that the center thereof is displaced from the central axis of the planetary gear 42 (the central axis O2 of the crank pin 10b). Connected adjacent to Specifically, the central axis of the eccentric shaft 44 is set so as to pass through the top dead center meshing point P1. Therefore, the eccentric shaft 44 rotates (rotates) around the central axis of the eccentric shaft 44 while rotating relative to the crankpin 10b with the revolution of the planetary gear 42, and is linear along the reciprocating direction. Reciprocate. In the present embodiment, the eccentric shaft 44 is formed in a disc shape.

  As shown in FIGS. 1 and 2, the counterweight 46 has an eccentric shaft 44 in the direction of the central axis O <b> 1 so that the center of gravity is located on the opposite side of the center of gravity of the eccentric shaft 44 with respect to the center axis of the planetary gear 42. Connected adjacent to

  As shown in FIGS. 1 and 2, the piston 50 includes an annular ring portion 52 that surrounds the eccentric shaft 44 via the second bearing 16, and extends from the annular portion 52 in the longitudinal direction of the cylinder 28. It has a piston rod 54 and a piston body 56 connected to the tip of the piston rod 54.

  The annular portion 52 is rotatable relative to the eccentric shaft 44. Therefore, the annular portion 52 linearly moves in the reciprocating direction so as to follow the linear movement of the eccentric shaft 44 along the reciprocating direction. That is, since the second bearing 16 is interposed between the eccentric shaft 44 and the annular portion 52, the rotational motion of the eccentric shaft 44 is not transmitted to the annular portion 52, and only the linear motion of the eccentric shaft 44 is performed. Is transmitted to.

  The piston rod 54 has a locus of the center of the eccentric shaft 44 when the eccentric shaft 44 reciprocates along the reciprocating direction (the locus of the top dead center meshing point P1 when the planetary gear 42 revolves around the central axis O1). It has a shape extending along the extension line. The piston rod 54 linearly moves in the cylinder 28 together with the linear movement of the annular portion 52 in the reciprocating direction.

  Here, the cylinder 28 has a shape that guides the piston 50 in the longitudinal direction while maintaining the posture at the top dead center of the piston 50, more specifically, the piston main body 56 is in the longitudinal direction of the cylinder 28. The piston main body 56 is guided so as to reciprocate along its longitudinal direction without being inclined. Therefore, when the planetary gear 42 revolves around the central axis O1 while rotating, the piston body 56 reciprocates linearly in the cylinder 28 while maintaining the same posture as that at the top dead center. Thereby, the piston main body 56 compresses the gas sucked from the suction line.

  As shown in FIGS. 1 and 3, the pump 60 includes a pump main body 62 that supplies lubricating oil to each bearing (bearing 12, first bearing 14, second bearing 16) and each gear, and a crankcase 21. A suction portion 66 for sucking lubricating oil from the oil reservoir into the pump body 62 is provided. The pump main body 62 is attached to a mounting wall 26 provided in the crankcase 21. The pump main body 62 is connected to the crankshaft 10 via a shaft coupling 64 disposed in a hole formed in the mounting wall 26. Specifically, the shaft coupling 64 connects a portion passing through the central axis O1 of the crank arm 10c far from the main shaft 10a and a rotor (not shown) built in the pump body 62. Therefore, the driving force of the crankshaft 10 is transmitted to the pump main body 62 via the shaft coupling 64. The pump main body 62 supplies the lubricating oil sucked up from the oil reservoir in the crankcase 21 by the suction portion 66 to each bearing and each gear through a supply path 68 (see FIG. 1) with a predetermined supply pressure.

  Here, the inside of the crankcase 21 is at the same level as the pressure of the gas sucked from the suction line, and the supply pressure when the pump 60 supplies the lubricating oil is purely applied to each bearing and each gear. This is the pressure required to supply the lubricating oil (hereinafter referred to as “pure supply pressure”). For this reason, the sealing pressure for sealing the leakage of the lubricating oil from the inside of the pump body 62 to the outside of the pump body 62 may be about the pure supply pressure. On the other hand, when the crankcase 21 has airtightness and pressure resistance and the pump 60 is disposed outside the case 20, the supply pressure when the pump 60 supplies the lubricating oil is the same as that of the crankcase 21. It is the sum of the internal pressure and the pressure for supplying lubricating oil to each bearing and each gear. Therefore, the seal pressure for sealing the leakage of the lubricating oil from the pump body 62 to the outside of the pump body 62 becomes higher than the pure supply pressure. That is, in this embodiment, since the crankcase 21 has airtightness and pressure resistance, and the pump 60 is housed in the case 20, the seal pressure of the pump 60 can be reduced. Become. Thereby, it becomes possible to ensure the sealing performance of the pump without using a high-performance pump excellent in sealing performance.

  Next, the operation at the time of operation of the compressor of the present embodiment will be described.

  When the prime mover is driven, the crankshaft 10 is rotationally driven. Accordingly, the planetary gear 42 rotates around the central axis O2 of the crankpin 10b while rotating relative to the crankpin 10b of the crankshaft 10 and meshes with the outer ring gear 30 while passing through the outer ring gear 30. Revolve around the central axis O1 of the main shaft 10a. Here, the top dead center meshing point P <b> 1 is set so as to coincide with a point closer to the piston 50 among the intersections of the pitch circle of the outer ring gear 30 and the longitudinal direction of the cylinder 28, and the planetary gear 42. Since the radius of the pitch circle P is half that of the outer ring gear 30, the planetary gear 42 revolves around the outer ring gear 30 with the meshing point of both gears maintained at the top dead center meshing point P1. Then, the eccentric shaft 44 reciprocates linearly along the reciprocating direction together with the planetary gear 42 while rotating (spinning) around its central axis. The piston 50 reciprocates linearly in the reciprocating direction while rotating relative to the eccentric shaft 44 so as to follow the reciprocating motion of the eccentric shaft 44. Thereby, the gas sucked from the suction line is compressed. The pump 60 supplies the lubricating oil sucked up from the oil reservoir in the crankcase 21 to each bearing and each gear as needed.

  As described above, in the compressor according to the present embodiment, the pump 60 is accommodated in the case 20, and therefore, when the lubricating oil leaks from the pump 60 when the lubricating oil is supplied to the bearing 12 and each gear. Even if it exists, the lubricating oil stays in the case 20 and does not leak out of the case 20. Therefore, it is not necessary to add parts such as an oil receiver that receives the lubricating oil leaked from the pump 60, and the leakage of the lubricating oil from the pump 60 is allowed. There is no need to use a pump. Further, since the compressor of the present embodiment includes a so-called hypocycloid mechanism having the outer ring gear 30 and the planetary gear 42, there is no severe lubrication condition like a compressor using a piston crank mechanism having a crosshead, In addition, since the rotational movement of the crankshaft 10 is directly converted into the reciprocating movement of the piston 50, the power transmission efficiency is superior to a compressor using a piston crank mechanism.

  In this embodiment, since the crankshaft 10 and the pump 60 are connected so that the pump 60 is driven by the rotation of the crankshaft 10, the prime mover that is the power source for rotating the crankshaft 10 is the pump 60. It is also used as a power source. Therefore, a dedicated power source for driving the pump 60 becomes unnecessary, and the structure is simplified.

  Further, in the present embodiment, since the oil buffer 27 is formed in the space surrounded by the mounting wall 26, the main body portion 22, and the crankshaft 10, the lubricating oil can be sufficiently supplied to the bearing 12 and the like.

  Further, in the compressor according to the present embodiment, the pump 60 is housed in the crankcase 21 and the crankcase 21 has airtightness and pressure resistance. It is possible to reduce the sealing pressure for sealing the leakage to about the pure supply pressure. Thereby, it becomes possible to ensure the sealing performance of the pump without using a high-performance pump excellent in sealing performance.

(Second embodiment)
FIG. 4 is a cross-sectional view showing the vicinity of the mounting wall 26 of the compressor according to the second embodiment of the present invention. In the second embodiment, only the parts different from the first embodiment will be described, and the description of the same structure, operation, and effect as in the first embodiment will be omitted.

  In the present embodiment, the cylindrical member 29 is attached to the surface of the attachment wall 26 opposite to the surface to which the pump 60 is attached. The end of the crankshaft 10 is inserted into the cylindrical member 29. An oil seal 29 a is attached between the cylindrical member 29 and the end of the crankshaft 10. Thereby, a space surrounded by the cylindrical member 29, the crankshaft 10, and the mounting wall 26 is formed. That is, in this embodiment, this space functions as the oil buffer 27. Therefore, in this embodiment, the volume of the oil buffer 27 can be adjusted flexibly by adjusting the inner diameter of the cylindrical member 29. The cylindrical member 29 may be formed by the mounting wall 26 and one member.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, an example in which the crankshaft 10 and the pump main body 62 are connected via the shaft joint 64 is shown. However, the pump 60 can be driven independently of the crankshaft 10. That is, a power source for driving the pump 60 may be provided separately from the prime mover that rotates the crankshaft 10. In this way, the driving of the crankshaft 10 and the driving of the pump 60 can be managed individually.

  The holding portion that holds the bearing 12 may be a separate member from the first wall 23 and the second wall 24. As long as the piston 50 reciprocates in a direction parallel to the radial direction of the outer ring gear 30, the piston 50 may be driven in an arbitrary direction such as a gravity direction.

DESCRIPTION OF SYMBOLS 10 Crankshaft 12 Bearing 20 Case 21 Crankcase 22 Main-body part 25 Pump accommodating part 26 Mounting wall 27 Oil buffer 28 Cylinder 30 Outer ring gear 40 Planetary member 42 Planetary gear 44 Eccentric shaft 46 Counterweight 50 Piston 52 Ring part 54 Piston rod 56 Piston body 60 Pump O1 Spindle center axis O2 Crankpin center axis P Pitch circle of planetary gear P1 Top dead center meshing point

Claims (3)

A crankshaft that is rotationally driven by a prime mover;
A bearing for receiving the crankshaft;
A case housing the crankshaft and the bearing;
An outer ring gear disposed so as to surround the crankshaft in the case;
A radius of the pitch circle is set to one half of the radius of the pitch circle of the outer ring gear, and a planetary gear that is inserted through the crankshaft so as to rotate relative to the crankshaft;
The planetary gear is connected to the planetary gear so as to rotate relative to the planetary gear, and the planetary gear rotates in the outer ring gear while meshing with the outer ring gear so that the inside of the case has a radial direction of the outer ring gear. A piston that reciprocates along parallel directions;
A pump for supplying lubricating oil to the bearing,
The pump is a compressor housed in the case. The compressor according to claim 1,
A compressor in which the crankshaft and the pump are connected such that the pump is driven by rotation of the crankshaft. The compressor according to claim 1 or 2,
A compressor in which an oil buffer is formed between a mounting wall to which the pump is mounted and the crankshaft.

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