JP4105124B2 - Screw type machine - Google Patents

Description

  The present invention is a screw-type machine in which a screw-type rotor is rotatably provided in a casing, and can be used as a motor by flowing a pressure fluid, and can rotate a main rotor. Relates to a screw-type machine that can be used as a pump.

  An example of a conventional screw type machine is shown in FIG. 5 (see, for example, Patent Document 1). The screw-type machine 1 includes a casing 3 having a high-pressure port 2 and a low-pressure port (not shown) that are spaced apart from each other. In the casing 3, one screw-type main rotor 4 and two A screw-shaped secondary rotor 5 is rotatably provided. The two slave rotors 5 are arranged in parallel with and in mesh with the main rotor 4.

  When the screw type machine 1 is used as a pump, for example, the main rotor 4 is rotated by a motor in a predetermined forward rotation direction, for example. As a result, low-pressure water is sucked from the low-pressure port and flows into the casing 3. The low-pressure water fills the respective grooves 4a and 5a of the main rotor 4 and the two sub-rotors 5, while increasing the pressure in the axial direction by the rotation of the main rotor 4 and the sub-rotors 5 and 5. Move to the high pressure port 2. In this way, the low-pressure water can be pressurized and discharged from the high-pressure port 2 as high-pressure water.

  Then, when the screw type machine 1 is used as a motor, for example, high pressure water is supplied to the high pressure port 2 and flows into the casing 3. This high-pressure water fills the grooves 4a and 5a of the main rotor 4 and the two sub-rotors 5, thereby rotating the main rotor 4 and the sub-rotors 5 and 5 in the reverse direction opposite to the above. Can be made. The high-pressure water moves while being lowered in the axial direction of the main rotor 4 or the like, and flows out from the low-pressure port as low-pressure water. Thereby, rotation can be taken out from the main rotor 4.

  According to this screw type machine 1, in order to balance the high pressure water passing through the high pressure port 2 shown in FIG. 5 with the force pressing the main rotor 4 in the axial direction (right direction) from the high pressure port 2 toward the low pressure port, A balance piston 6 and a disc 7 are connected to a portion of the rotor 4 on the high pressure port 2 side. That is, the balance piston 6 and the disc 7 receive the pressure of the high-pressure water passing through the high-pressure port 2 (high-pressure chamber 2a), and move the main rotor 4 in the axial direction (leftward) from the low-pressure port toward the high-pressure port 2. Generates a pressing force. As a result, the rightward force acting on the main rotor 4 and the leftward force acting on the balance piston 6 and the like cancel each other, so that a large axial direction (thrust direction) is exerted on the main rotor 4. You can prevent power from working.

  When an axial force is applied, it is necessary to provide a thrust bearing for rotatably holding the main rotor 4 or to increase the size of the bearing so that the force can be maintained. By providing the balance piston 6, the thrust bearing can be omitted or a small bearing can be used.

Further, as shown in FIG. 5, each of the two slave rotors 5 is rotatably held by a cup-shaped bush 8 at each end (journal) 5 b on the high-pressure side. And each clearance gap 8a formed by the inner surface of each bush 8 and the surface of each edge part 5b of each subrotor 5 currently hold | maintained at these each inner surface is the through-hole 9a, the clearance gap 9b, the space 9c, The low pressure port communicates with the groove 9d and the communication hole 9e. As a result, even if the high-pressure water passing through the high-pressure port 2 flows into each gap 8a, the high-pressure water (however, the high-pressure water flowing into the gap 8a has a relatively low pressure due to a pressure drop) passes through. It is possible to escape to the low pressure port through the hole 9a and the like, and as a result, the pressure in each gap 8a can be reduced. Therefore, the force which presses each subrotor 5 to the right direction of FIG. 5 by the pressure water which flows in into each clearance gap 8a is removable. Thus, by preventing axial force from being applied to the slave rotor 5, it is possible to prevent the slave rotor 5 from being compressed and bent, and to prevent the end portion 5b from being worn or seized. .
Japanese Patent Publication No. 60-10193

  However, in the conventional screw-type machine 1 shown in FIG. 5, the high pressure port 2 is provided with the balance piston 6, the disk 7, the through hole 9 a, etc., so that high pressure water is passed through the high pressure port 2. In such a case, the high-pressure water can prevent the main rotor 4 and the two sub-rotors 5 and 5 from being subjected to a large axial force. In this case, there is a problem that a large force in the axial direction (left direction) is applied to the main rotor 4 and the sub rotors 5 and 5. That is, for example, when the screw type machine 1 is used as a motor and the main rotor 4 is rotated in the forward rotation direction opposite to the above, it is necessary to supply high pressure water to the low pressure port. When water is supplied to the low-pressure port, high-pressure water passing through the low-pressure port generates a force that presses the main rotor 4 and the slave rotors 5 and 5 in the axial direction (leftward) from the low-pressure port toward the high-pressure port 2. However, the balance piston 6 and the disk 7 for generating the rightward force to be balanced with the leftward force are not provided at the end of the main rotor 4 on the low pressure port side. 5 is not provided with a configuration for reducing the pressure applied to the end portion 5b on the low pressure port side (the through hole 9a, etc.), the main rotor 4 and the respective sub rotors 5 and 5 have a large leftward direction. There is a problem that it takes power.

  Therefore, when the conventional screw type machine 1 is used as a motor and it is desired to obtain both forward and reverse rotations, for example, the screw direction of the screw type machine 1 and the main rotor 4 shown in FIG. It is necessary to prepare two other screw type machines formed in reverse. Thus, by preparing two screw type machines and supplying high pressure water to the high pressure port 2 of one screw type machine 1, the rotation of the main rotor 4 in the reverse direction can be obtained. Then, by supplying high-pressure water to the high-pressure port of the other screw type machine, the rotation of the main rotor in the normal rotation direction can be obtained.

  The present invention has been made in order to solve the above-described problems. Even when a high-pressure fluid is circulated so that the main rotor rotates forward and backward, a large axial force is exerted on the main rotor. Can be used as a motor that can rotate forward and reverse, and a screw type machine that can be used as a pump that can discharge high-pressure fluid from any of the two ports is provided. The purpose is to do.

  The present invention includes a casing having two ports, a screw-type main rotor is rotatably provided in the casing, and a working fluid flows from the one port to fill the groove of the main rotor. In a screw-type machine that moves in the axial direction as the main rotor rotates and flows out from the other port, the main rotor is balanced with the force of the working fluid acting on the main rotor. The balance piston is provided on each side corresponding to each of the two ports.

  According to the screw type machine of the present invention, when the main rotor is rotated forward (or reverse) when used as a motor, the high pressure working fluid (high pressure fluid) is supplied to one (or the other) port and the casing. Let it flow into. This high-pressure fluid can cause the main rotor to rotate forward (or reverse) by filling the groove of the main rotor. Then, the high-pressure fluid moves while being reduced in pressure in the axial direction of the main rotor, becomes low-pressure fluid, and flows out from the other (or one) port.

  When this screw type machine is used as a pump, when a high-pressure fluid is discharged from one (or the other) port, the main rotor is driven in a predetermined forward (or reverse) direction by a motor. Thereby, the low-pressure fluid can be sucked from the other (or one) port, and the high-pressure fluid can be discharged from the one (or the other) port.

  In this way, even when high-pressure fluid passes through any of the two ports, the balance piston is provided on each side corresponding to each of the two ports of the main rotor. A predetermined axial force acting on the child and a force opposite to that acting on the balance piston cancel each other, so that a large axial force does not act on the main rotor.

  And in the screw type machine according to the present invention, when a screw-type slave rotor is rotatably provided in parallel with the main rotor, and the slave rotor is disposed in the casing in a state of meshing with the main rotor. Good. In this way, the working fluid can be moved in the axial direction in a substantially sealed state by the meshing of the main rotor and the sub-rotor and the contact between the main rotor and the sub-rotor and the casing. Therefore, this screw type machine can be operated efficiently.

  In the screw type machine according to the present invention, both end portions of the slave rotor are rotatably held by cup-shaped bushes, and are held by the inner surfaces of the two bushes and the inner surfaces thereof. When the slave rotor is provided with a communication hole for communicating two gaps formed by the surface of each end of the slave rotor with each other, and at least one of the gap and the outside of the casing are communicated with each other by a drain hole. Good. If it does in this way, since each each edge part of a subrotor is hold | maintained by the bush, it can reduce that each edge part receives the axial force by a high pressure fluid. Then, working fluid (relatively low pressure due to the pressure drop) flows into the gap between each end of the slave rotor and the bush, and this working fluid is connected to the communication hole provided in the slave rotor, And since it is discharged | emitted through a drain hole, the force which pushes each edge part by the working fluid which flowed into the clearance gap to an axial direction can be eliminated. Therefore, even when the follower rotor rotates in either forward or reverse direction, the follower rotor is compressed and bent, thereby preventing the peripheral surface from being seized, its respective end portions being worn out, or being seized.

  Furthermore, in the screw-type machine according to the present invention, it is preferable that a rotation take-out pin is provided at an end of the main rotor, and the turn-out pin penetrates the casing and is exposed to the outside. If it does in this way, rotation of a main rotor can be taken out with a rotation taking-out pin. The rotation taken out by the rotation take-out pin can be converted into an electrical signal by, for example, an encoder, and the rotation speed, the rotation speed, etc. of the main rotor can be taken out from this signal. This rotary take-out pin is particularly effective when the screw type machine is used as, for example, a hydraulic motor.

  According to the screw type machine of the present invention, it is possible to prevent a large axial force from acting on the main rotor even if the high pressure fluid passes through any of the two ports. Even if the bearing for supporting the main rotor is not enlarged or the bearing is omitted, it is possible to change the port through which the high-pressure fluid passes. That is, the main rotor can be used for normal rotation and reverse rotation.

  Therefore, this screw type machine can be used as, for example, a motor capable of normal rotation and reverse rotation of the main rotor. As a result, unlike the conventional screw type machine 1 shown in FIG. 5, it is not necessary to prepare two screw type machines for forward rotation and reverse rotation, which is economical. Conventionally, for example, there are vane type, gear type, and piston type hydraulic motors. However, since the present invention adopts a screw type, the noise level and length are lower than those of these conventional hydraulic motors. Lifetime and high speed operation can be obtained.

  Further, by changing the direction of rotation of the main rotor, it can be used as a pump that can discharge high-pressure fluid from any of the two ports. Therefore, when each port is used as a discharge port or a suction port, it is only necessary to change the rotation direction of the main rotor, and it is not necessary to provide a switching valve or the like, which is economical.

  Furthermore, when each port of a plurality of screw type machines of the present invention is connected in series, a high-pressure fluid passes through both ports of each machine. Even in such a case, each main rotor It is possible to prevent the axial force from acting.

  Hereinafter, an embodiment of a screw type machine according to the present invention will be described with reference to FIGS. This screw type machine 11 can be used as, for example, a hydraulic motor or a hydraulic pump. As the working fluid, special liquids such as oil, water, viscose, food and medicine, and gases such as air can be used. As shown in the longitudinal sectional view of FIG. 1, a single screw-shaped main rotor 13 and two screw-shaped secondary rotors 14 are provided in the casing 12.

  As shown in FIG. 1, the casing 12 has a pump casing 15 disposed in the center, and a front cover 16 and a rear cover 17 are disposed at both ends thereof. The front cover 16 and the rear cover 17 are fastened and fixed to the pump casing 15 with bolts 18 and 18. A through hole 16a is formed in the front cover 16, and a seal cover 19 is attached to the through hole 16a. A through hole is also formed in the rear cover 17, and a rear piston cover 20 is attached to the through hole.

  The casing 12 is formed with an accommodation hole 21 into which the main rotor 13 and the two secondary rotors 14 and 14 are fitted. A first port 22 is formed at the end of the pump casing 15 on the front cover 16 side, and the first port 22 communicates with one left end of the accommodation hole 21. Further, a second port 23 is formed in the rear cover 17, and the second port 23 communicates with the other right end portion of the accommodation hole 21.

  As shown in FIG. 1, the screw-type main rotor 13 has a main shaft portion 24. One left end portion of the main shaft portion 24 is formed as a drive end portion 24 a, and the drive end portion 24 a protrudes outward from the seal cover 19. The main shaft portion 24 is formed with a spiral ridge 13a over a range from the first port 22 to the second port 23. A spiral groove 13b is formed along the spiral ridge 13a. Is formed.

  As shown in FIG. 1, a portion of the main shaft portion 24 accommodated in the front cover 16 is referred to as a first balance piston (hereinafter simply referred to as a “first piston”) at a distance from the first port 22. ) 25 is provided. Further, a second balance piston (hereinafter simply referred to as “second piston”) 26 is provided in a portion of the main shaft portion 24 accommodated in the rear piston cover 20. The outer peripheral surface of the second piston 26 is slidably in contact with the inner peripheral surface of the rear piston cover 20. Further, the diameters of the first and second pistons 25 and 26 are formed larger than the diameter of the main shaft portion 24.

  A bearing (ball bearing) 27 is mounted in the through hole 16 a of the front cover 16. The bearing 27 has a main shaft portion 24 inserted therethrough, and supports the main shaft portion 24 so as to be rotatable. The bearing 27 is fixed in a state of being sandwiched between the first piston 25 and the nut 28. Further, a seal device (floating bush, backup ring, and seal member) 29 is disposed between the outer peripheral surface of the first piston 25 and the inner peripheral surface of the front cover 16, and is sealed by this. .

  As shown in FIG. 1, the two screw-type secondary rotors 14 and 14 are provided in the casing 12 so as to be rotatable in parallel with the main rotor 13 and meshing with the main rotor 13. Yes. Since the two slave rotors 14 are equivalent to each other, the one disposed on the upper side of the figure will be described, and the description of the one disposed on the lower side will be omitted. As in the case of the main rotor 13, the slave rotor 14 is formed with a spiral protrusion 14a over a range from the first port 22 to the second port 23, and the spiral protrusion 14a. A spiral groove 14b is formed along the line.

  In addition, the protrusion 13a of the main rotor 13 and the protrusion 14a of the subrotor 14 are formed as spiral protrusions in opposite directions. The outer peripheral edges of the spiral ridges 13a and 14a of the main rotor 13 and the two slave rotors 14 and 14 are slidable with the inner surface of the accommodation hole 21 formed in the casing 12. In contact. Both end portions 14c and 14d of the subrotor 14 are formed as short cylindrical journals, and the end portions 14c and 14d are rotatably held by cup-shaped first and second bushes 30 and 31. ing.

  The slave rotor 14 is formed with a communication hole 32 along the axial direction. As shown in FIG. 1, the communication hole 32 includes inner surfaces of the first and second bushes 30 and 31, and surfaces of the end portions 14c and 14d of the slave rotor 14 held by the inner surfaces. The two first and second gaps 33 and 34 formed in the above are communicated with each other. The second gap 34 formed in the second bush 31 disposed on the second port 23 side is communicated with the outside of the casing 12 via the drain hole 35. The drain hole 35 is formed in the second bush 31 and the rear piston cover 20. Therefore, the first and second gaps 33 and 34 formed in the first and second bushes 30 and 31 that rotatably hold the slave rotor 14 are connected to the casing 12 via the drain holes 35. It communicates with the outside. In this way, the four gaps 33, 33, 34, 34 formed by the four end portions of the two slave rotors 14 communicate with the outside of the casing 12 through the drain holes 35. Yes.

  Further, the first bush 30 that holds the left end portion 14c shown in FIG. 1 of the slave rotor 14 is disposed between the first piston 25 and the first port 22, and the second bush that holds the right end portion 14d. 31 is disposed between the second piston 26 and the second port 23. The first and second bushes 30 and 31 are sandwiched between the end portions 14c and 14d of the follower rotor 14, the front cover 16 and the rear piston cover 20, and are fixed so as not to move in the axial direction. Has been.

  As shown in FIGS. 1 and 2, the housing hole 21 of the pump casing 15 has first and second fluid chambers 36, 37 in portions where the first and second ports 22, 23 are arranged. Is formed. The first and second fluid chambers 36 and 37 are formed by the groove portions 13b and 14b formed in the main rotor 13 and the slave rotors 14 and the corresponding first and second ports 22 and 23. The working fluid (for example, special liquids such as oil, water, viscose, food, and medicine, and gas such as air) can easily flow between them.

  Further, as shown in FIG. 1, a rotation take-out pin 38 is provided at the end of the main rotor 13 on the second piston 26 side. The rotation extraction pin 38 is exposed to the outside of the casing 12 through an insertion hole 39 formed in the rear piston cover 20.

  According to the screw type machine 11 shown in FIG. 1 configured as described above, the main rotor 13 can be rotated in both forward and reverse directions, and can be used as, for example, a hydraulic motor and a hydraulic pump. First, when the screw type machine 11 is used as a hydraulic motor, for example, when the main rotor 13 is rotated forward (or reverse), high pressure oil is supplied to the first (or second) port 22 (or 23). And flow into the casing 12. The high-pressure oil can cause the main rotor 13 to rotate forward (or reverse) by filling the main rotor 13 and the groove portions 13b, 14b of the two slave rotors 14, 14. The high-pressure oil moves while being stepped down in the axial direction (right direction in FIG. 1) of the main rotor 13 and each of the follower rotors 14 and 14 to become low-pressure oil, and the second (or first) port. 23 (or 22). The two sub-rotors 14 and 14 rotate in the opposite direction to the main rotor 13 as the main rotor 13 rotates.

  Next, when this screw type machine 11 is used as a hydraulic pump, the driving end 24a of the main rotor 13 shown in FIG. 1 and the rotating shaft of a motor (not shown) are connected. For example, when high-pressure oil is discharged from the first (or second) port 22 (or 23), the main rotor 13 is driven in a predetermined forward (or reverse) direction by a motor. Thereby, the low pressure oil can be sucked from the second (or first) port 23 (or 22). The low-pressure oil fills the grooves 13b and 14b of the main rotor 13 and the two sub-rotors 14 and 14, and is boosted in the axial direction by the rotation of the main rotor 13 and the sub-rotors 14 and 14. Moving toward the first (or second) port 22 (or 23). In this manner, the low-pressure oil can be pressurized and discharged from the first (or second) port 22 (or 23) as high-pressure oil. The two sub-rotors 14 and 14 rotate in the opposite direction to the main rotor 13 as the main rotor 13 rotates.

  In this way, the first and second ports 22, 23, regardless of which port passes high pressure oil, the first and second sides corresponding to the two ports 22, 23 of the main rotor 13 are connected to the first and second ports 22, 23. Since the second pistons 25 and 26 are provided, the force of the high-pressure oil acting on the main rotor 13 in a predetermined axial direction (right direction or left direction in FIG. 1), and the first and second pistons 25 and 26 The forces in the opposite direction (the left direction or the right direction in FIG. 1) acting on each other cancel each other, so that a large axial force does not act on the main rotor 13.

Next, the force acting on the main rotor 13 and the first and second pistons 25 and 26 when high-pressure oil passes through the first port 22 will be described with reference to FIGS. FIG. 3A is a view of the main rotor 13 and the two slave rotors 14 and 14 as seen from the direction AA in FIG. The main rotor 13 is formed by intersecting an annular portion (area S ₁ ) 40 formed on the side surface of the protrusion 13 a and the main rotor 13 and the two sub-rotors 14 and 14. Pressure by high-pressure oil (for example, 21 MPa) acts on each of the lens-shaped portions (area S ₂ ) 41 and 41. Due to the pressure acting on this area (S ₁ + 2 × S ₂ ), the force F ₁ acts on the main rotor 13. The force F ₁ is a force for pressing the main rotor 13 rightward in FIG. 1.

FIG. 3B is a view of the first piston 25 as viewed from the first port 22 side. In the first piston 25, pressure (for example, 21 MPa) by high-pressure oil acts on an annular portion (area S ₃ (= S ₁ + 2 × S ₂ )) 42 formed on the inner surface of the first piston 25. Force _{F 2} acting on the first piston 25 becomes a force _{F 2} for pressing the main rotor 13 to the left in FIG. 1. The areas S ₁ , S ₂ , and S ₃ are determined so that the force F ₂ acting on the first piston 25 and the force F ₁ acting on the main rotor 13 have the same magnitude. Since the forces F ₁ and F ₂ are in opposite directions, they can be canceled out to prevent a large axial force from acting on the main rotor 13.

  The high-pressure oil passing through the first port 22 shown in FIG. 1 passes through the gap formed between the outer peripheral surfaces of the two first bushes 30 and 30 and the inner peripheral surface of the pump casing 15, so that the first piston 25 will come into contact with the inner side surface 42 of the 25. However, since the sealing device 29 is provided between the outer peripheral surface of the first piston 25 and the inner peripheral surface of the front cover 16, the high-pressure oil is sealed between the first piston 25 and the sealing device 29. When flowing into the tank, the pressure drops to a relatively low pressure and is discharged to the outside through the drain port 43. Thereby, the pressure by the high pressure oil does not act on the outer surface of the first piston 25 (the left side portion of the first piston 25 in FIG. 1).

The second piston 26 is configured similarly to the first piston 25, even if the high pressure oil passes through the second port 23, the force F ₂ acting on the second piston 26 (force acting in the right direction in FIG. 1) The areas S ₁ , S ₂ , and S ₃ are determined so that the force F ₁ acting on the main rotor 13 (force acting in the left direction in FIG. 1) has the same magnitude. In the same manner as described above, the forces F ₁ and F ₂ are directed in opposite directions, and thus cancel each other, so that a large axial force does not act on the main rotor 13.

  As described above, according to the screw type machine 11, even if the high pressure oil passes through any of the first and second ports 22 and 23, a large axial force is applied to the main rotor 13. Since it does not work, it is possible to change the ports 22 and 23 through which the high-pressure oil passes without increasing the size of the bearing 27 that supports the main rotor 13. That is, the main rotor 13 can be used for normal rotation and reverse rotation. Of course, the bearing 27 can be omitted.

  Next, with reference to FIG.1 and FIG.4, the force which acts on each of the two subrotors 14 and 14 when high pressure oil passes the 1st port 22 is demonstrated. However, since the force acting on each of the slave rotors 14 and 14 is the same, one slave rotor 14 will be described and the description of the other slave rotor 14 will be omitted. As shown in FIG. 1, the left end portion 14 c of the slave rotor 14 is rotatably held by the first bush 30, and the first bush 30 is fixedly attached to the pump casing 15. It is possible to reduce the left end portion 14c of the slave rotor 14 from being subjected to axial force (right direction in FIG. 1) by the high pressure oil. The high pressure oil passing through the first port 22 flows into the first gap 33 formed between the left end portion 14 c of the slave rotor 14 and the inner surface of the first bush 30, but the high pressure oil is in the first gap 33. The pressure drops to a relatively low pressure when it flows into the rotor, and the low-pressure oil is discharged to the outside through the communication hole 32 and the drain hole 35 provided in the slave rotor 14. Accordingly, it is possible to prevent the pressure oil flowing into the first gap 33 from pressing the left end portion 14c of the slave rotor 14 in the axial direction (right direction in FIG. 1). FIG. 4 shows a state in which high-pressure oil passing through the first port 22 is discharged to the outside through the first gap 33, the communication hole 32, the second gap 34, and the drain hole 35 of the first bush 30. . Of course, when the low-pressure oil passes through the first port 22, the low-pressure oil is passed through the first gap 33, the communication hole 32, the second gap 34, and the drain hole 35 of the first bush 30 in the same manner as described above. Can be discharged to the outside.

  Further, when high-pressure oil or low-pressure oil passes through the second port 23, the high-pressure oil or low-pressure oil can be discharged to the outside through the second gap 34 and the drain hole 35 of the second bush 31. The second gap 34 is formed between the right end portion 14 d of the slave rotor 14 and the inner surface of the second bush 31.

  Therefore, even when the two slave rotors 14 and 14 rotate in either the forward or reverse direction, the slave rotors 14 or 14 are compressed and bent, thereby causing the peripheral surface to be burned out or the end portions 14c thereof. , 14d can be prevented from being worn or seized.

  Accordingly, the screw type machine 11 can be used as a motor capable of rotating the main rotor 13 in the normal direction and the reverse direction, for example. As a result, unlike the conventional screw type machine 1 shown in FIG. 5, it is not necessary to prepare two screw type machines for forward rotation and reverse rotation, which is economical. Conventionally, for example, there are vane type, gear type, and piston type as the hydraulic motor, but in the present invention, since the screw type is adopted, the noise and length are lower than those of the conventional hydraulic motor. Lifetime and high speed operation can be obtained.

  Further, by changing the rotation direction of the main rotor 13, the pump can be used as a pump capable of discharging high-pressure oil from any of the first and second ports 22 and 23. Therefore, when each port 22, 23 is used as a discharge port or a suction port, it is only necessary to change the rotation direction of the main rotor 13, and it is not necessary to provide a switching valve or the like, which is economical.

  Further, when a plurality of screw type machines 11 shown in FIG. 1 are prepared and the first and second ports 22 and 23 of each machine 11 are connected in series (when used in multiple stages), Although high-pressure oil passes through the first and second ports 22 and 23 of the machine 11, even in such a case, it is possible to prevent axial forces from acting on the main rotors 13. it can.

  As shown in FIG. 1, the screw type machine 11 includes two main rotors 14 and 14 that mesh with the main rotor 13 and are in line contact with each other. Since each subrotor 14 and 14 and the inner peripheral surface of the casing 12 are in contact with each other, the pressure oil can be moved in the axial direction while being substantially sealed in the groove portions 13b and 14b. Therefore, this screw type machine 11 can be operated efficiently.

  Further, as shown in FIG. 1, a rotation take-out pin 38 is provided at the end of the main rotor 13 on the second piston 26 side, so that the rotation of the main rotor 13 can be taken out by this rotation take-out pin 38. . The rotation of the main rotor 13 can be converted into an electrical signal, for example, by connecting an encoder to the rotation take-out pin 38, and the rotation speed, the rotation speed, etc. of the main rotor 13 are extracted from this signal. be able to. Thus, taking out the rotation speed, rotation speed, and the like of the main rotor 13 is particularly effective when the screw-type machine 11 is used as, for example, a hydraulic motor.

  However, in the above embodiment, as shown in FIG. 1, two slave rotors 14 and 14 are rotatably provided on both sides in parallel with the master rotor 13, and each of the two slave rotors 14 is provided. , 14 are arranged in the casing 12 in mesh with the main rotor 13, but instead, a single subrotor 14 is rotatably provided in parallel with the main rotor 13, and this subrotation is provided. You may arrange | position in the casing 12 in the state which the child 14 meshes with the main rotor 13. In addition, although the two slave rotors 14 are provided, the two slave rotors 14 may be omitted.

  And the screw type machine 11 of the said embodiment can be used as a hydraulic motor for driving, for example, a steelmaking press or a ship screw. Furthermore, it can be used as a hydraulic pump for driving various hydraulic motors.

  Moreover, in the said embodiment, as shown in FIG. 1, although the drain hole 35 was provided in the 2nd bush 31 grade | etc., Instead of this or in addition to this, the drain hole 35 is made into the 1st bush 30 and pump. It may be formed in the casing 15 so that the first gap 33 communicates with the outside of the casing 12.

  As described above, the screw-type machine according to the present invention prevents a large axial force from being applied to the main rotor even when a high-pressure fluid is circulated so that the main rotor rotates forward and backward. Thus, the screw can be used as a motor that can rotate forward and reverse, and can be used as a pump that can discharge high-pressure fluid from any port. Suitable for application to mold machines.

It is a longitudinal section showing a screw type machine concerning an embodiment of this invention. It is a half sectional view of the screw type machine concerning the embodiment. It is a figure explaining the balance of the axial force which acts on the main rotor and the 1st piston of the screw type machine concerning the embodiment, (a) is an AA sectional view of a main rotor and each subrotor, (B) is a longitudinal cross-sectional view which shows the inner surface of a 1st piston. It is a figure explaining the flow of the pressure oil which flows in into each clearance gap formed in the both ends of the subrotor of the embodiment. It is a partial notch sectional view which shows the conventional screw type machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Screw type machine 12 Casing 13 Main rotor 13a, 14a Projection 13b, 14b Groove part 14 Subrotor 15 Pump casing 16 Front cover 17 Rear cover 21 Accommodating hole 22 1st port 23 2nd port 24 Main shaft part 25 1st piston 26 2nd piston 27 Bearing 30 1st bush 31 2nd bush 32 Communication hole 33 1st clearance 34 2nd clearance 35 Drain hole 36 1st fluid chamber 37 2nd fluid chamber 38 Rotation take-out pin 39 Insertion hole 40, 42 Annular Part 41 Lens shape part

Claims (4)

A casing having two ports, wherein a screw-type main rotor is rotatably provided in the casing, and a working fluid flows from the one port to fill a groove of the main rotor, and the main rotor In the screw-type machine that moves in the axial direction along with the rotation of and flows out of the other port,
The screw characterized in that the main rotor is provided with a balance piston on each side corresponding to each of the two ports to balance the force by the working fluid acting on the main rotor. Mold machine.   A screw-type slave rotor is rotatably provided in parallel with the main rotor, and the slave rotor is disposed in the casing in a state of being engaged with the main rotor. The screw type machine according to 1.   Both end portions of the slave rotor are rotatably held by cup-shaped bushes, the inner surfaces of the two bushes, and the surfaces of the end portions of the slave rotor held by the inner surfaces. 3. The communication rotor according to claim 2, wherein a communication hole is provided in the slave rotor, and at least one of the clearances and the outside of the casing are communicated by a drain hole. Screw type machine.   The screw type machine according to any one of claims 1 to 3, wherein a rotation extraction pin is provided at an end of the main rotor, and the rotation extraction pin penetrates the casing and is exposed to the outside. .

Images