Scroll fluid machine and motor

Abstract

This scroll fluid machine is provided with a scroll mechanism part having a spiral first wrap and a spiral second wrap that rotates relative to the first wrap around an axis, a second drive shaft that rotates around the axis and causes the second wrap to orbit, and a backflow prevention mechanism through which the second drive shaft is inserted. The second drive shaft is provided with an end surface opening that communicates with the inside of the scroll mechanism part, a peripheral surface opening that opens in a direction intersecting the axis line and that is formed on the outer peripheral surface of the second drive shaft, and a through hole that connects the end surface opening and the peripheral surface opening. The backflow prevention mechanism has a communication part that communicates with the outside of the scroll mechanism part and switches between a state of being faced by the peripheral surface opening and a state of not being faced by the peripheral surface opening due to the rotation of the second drive shaft.

Description

Scroll fluid machinery and motors

[0001] The present disclosure relates to scroll fluid machinery and motors.

[0002] The scroll fluid machine disclosed in Patent Document 1 includes a pair of scrolls. Each of the pair of scrolls has a wrap. The pair of wraps form pockets that trap working fluid. Each of the pair of scrolls receives torque from a motor and rotates. As a result, the pockets trapping the working fluid move toward the rotation axis of the scroll. The volume of these pockets decreases, compressing the working fluid.

[0003] The pressure of the working fluid moving through the scroll fluid machine fluctuates according to the rotation of the pair of scrolls. We will focus on the magnitude relationship between the internal pressure of the scroll fluid machine and the internal pressure of the piping system connected to the discharge port of the scroll fluid machine. From a relatively broad perspective, it can be said that the internal pressure of the scroll fluid machine is equal to or greater than the internal pressure of the piping system.

[0004] Utility Model Application Publication No. 02-031390 Publication No. 09-072285

[0005] However, from a relatively small perspective, there may be a moment when the internal pressure of the scroll fluid machine becomes lower than the internal pressure of the piping system. In this case, a backflow of the working fluid from the piping system toward the scroll fluid machine occurs. The backflow of the working fluid is a factor that reduces the efficiency of the scroll fluid machine. For example, Patent Document 2 discloses a scroll fluid machine equipped with a check valve for suppressing backflow of the medium when it occurs. However, from the perspective of the reduction in efficiency of the scroll fluid machine, a technology for more effectively preventing backflow of the working fluid is desired.

[0006] The present disclosure describes a scroll fluid machine that can prevent backflow of a working fluid.

[0007] A scroll fluid machine according to one embodiment of the present disclosure comprises a scroll mechanism having a first spiral wrap and a second spiral wrap that revolves relative to the first wrap around a rotation axis, a shaft that rotates around the rotation axis and revolves the second wrap, and a shaft arrangement portion through which the shaft portion is inserted. The shaft portion has a first opening that communicates with the interior of the scroll mechanism, a second opening that opens in a direction intersecting the rotation axis and is formed on the outer surface of the shaft portion, and a hole that connects the first opening and the second opening. The shaft arrangement portion has a communication portion that communicates with the outside of the scroll mechanism and that switches between a state in which the second opening faces the shaft portion and a state in which the second opening does not face the shaft portion as the shaft portion rotates.

[0008] The shaft of this scroll fluid machine has a hole including a first opening communicating with the interior of the scroll mechanism, and this hole also includes a second opening provided on the outer circumferential surface of the shaft. Therefore, the shaft can form a path communicating with the interior of the scroll mechanism. The scroll fluid machine also has a shaft arrangement section in which the shaft is disposed. The shaft arrangement section has a communication section communicating with the outside of the scroll mechanism. This communication section switches between a state in which the second opening faces the outside and a state in which the second opening does not face the outside, depending on the rotation of the shaft. With this configuration, it is possible to switch between a state in which the inside and outside of the scroll mechanism are connected and a state in which the inside and outside of the scroll mechanism are not connected, depending on the rotation of the shaft. When the inside and outside of the scroll mechanism are connected, working fluid can be exchanged between the inside and outside of the scroll mechanism. When the inside and outside of the scroll mechanism are not connected, working fluid cannot be exchanged between the inside and outside of the scroll mechanism. In other words, backflow of working fluid from the outside to the inside of the scroll mechanism can be prevented.

[0009] The shaft portion of the scroll fluid machine may have a wall portion facing the second opening. With this configuration, it is possible to switch between a state in which the inside and outside of the scroll mechanism are connected and a state in which the inside and outside of the scroll mechanism are not connected in response to rotation of the shaft portion.

[0010] The wall of the scroll fluid machine may have a first inner circumferential surface that contacts the outer circumferential surface of the shaft portion and a second inner circumferential surface that does not contact the outer circumferential surface of the shaft portion. With this configuration, during one rotation of the shaft portion, the inside and outside of the scroll mechanism can be disconnected when the second opening faces the first inner circumferential surface, and the inside and outside of the scroll mechanism can be connected when the second opening faces the second inner circumferential surface.

[0011] The shaft portion mounting portion of the scroll fluid machine may hold a bearing that supports the rotation of the shaft portion. With this configuration, the shaft portion can be rotatably supported.

[0012] The scroll fluid machine may further include seal members provided before and after the hole in the axial direction of the shaft portion. This configuration makes it possible to suppress leakage of the working fluid.

[0013] The scroll fluid machine may further include a drive unit that applies a rotational driving force to the shaft unit, and a control unit that switches between an operation of the drive unit rotating the shaft unit and an operation of the drive unit stopping the rotation of the shaft unit, and the control unit may stop the rotation of the shaft unit when the second opening faces the first inner circumferential surface. With this configuration, it is possible to prevent backflow of working fluid from the outside into the scroll fluid machine when the operation of the scroll fluid machine is stopped.

[0014] The scroll mechanism of the scroll fluid machine may include a first drive scroll including a first wrap and connected to a first shaft portion, which is a shaft portion, and a second drive scroll including a second wrap and connected to a second shaft portion different from the first shaft portion. With this configuration, a so-called spinning type scroll fluid machine can be configured.

[0015] The scroll fluid machine may further include a first drive unit that applies a rotational driving force to the first shaft portion and a second drive unit that applies a rotational driving force to the second shaft portion. With this configuration, the rotational driving force can be applied to each of the first shaft portion and the second shaft portion.

[0016] In the scroll fluid machine, a heat insulating member made of a material having a thermal conductivity lower than that of the shaft portion may be disposed on the inner circumferential surface of the hole. With this configuration, it is possible to suppress the transfer of heat from the working fluid to the shaft portion.

[0017] Another aspect of the present disclosure provides a scroll fluid machine comprising: a scroll mechanism having a first spiral wrap and a second spiral wrap that revolves around a rotation axis relative to the first wrap; a shaft that rotates around the rotation axis to revolve the second wrap; and a drive unit that applies a rotational driving force to the shaft. The shaft has a first opening communicating with the interior of the scroll mechanism; a second opening that opens in a direction intersecting the rotation axis and is formed on the outer peripheral surface of the shaft between the scroll mechanism and the drive unit; and a hole connecting the first opening and the second opening. The scroll fluid machine has a drive unit connected to the shaft. The shaft discharges working fluid from the scroll mechanism through the second opening. The second opening is formed on the outer peripheral surface of the shaft between the scroll mechanism and the drive unit. Therefore, the working fluid can be discharged without reaching the drive unit. As a result, the influence of the state of the working fluid on the drive unit can be suppressed.

[0018] Another embodiment of the present disclosure provides a motor including a motor shaft, a rotor including a magnet that rotates with the motor shaft, a stator disposed around the rotor and including a coil, and a case that houses the rotor and stator. The motor shaft includes an output end protruding from the case. The output end may include a first hole including a first opening on an end surface of the output end and extending in the direction of the rotational axis of the motor shaft, and a second hole communicating with the first hole and extending in a direction intersecting the rotational axis and including an opening on the outer peripheral surface. The motor shaft of this motor includes the first hole including the first opening on the end surface of the output end and extending in the direction of the rotational axis of the motor shaft. The first hole can receive working fluid from a device connected to the motor shaft. The motor shaft further includes a second hole communicating with the first hole and extending in a direction intersecting the rotational axis and including an opening on the outer peripheral surface. The second hole can discharge the working fluid received in the first hole to the outside. The second hole portion includes an opening formed on the outer peripheral surface, so that the received working fluid can be discharged without reaching the rotor portion, thereby suppressing the influence of the state of the working fluid on the rotor portion.

[0019] According to the scroll fluid machine of the present disclosure, backflow of the working fluid can be prevented.

[0020] FIG. 1 is a schematic diagram showing a configuration including a scroll fluid machine of an embodiment. FIG. 2 is a perspective view showing a cutaway portion of the scroll fluid machine of the embodiment. FIG. 3 is a cross-sectional view of the scroll fluid machine of the embodiment. FIG. 4 is an enlarged cross-sectional perspective view showing a main portion of the scroll fluid machine shown in FIG. 3. FIG. 5(a) is a cross-sectional view illustrating a backflow prevention mechanism for preventing backflow of a working fluid. FIG. 5(b) is a cross-sectional view illustrating a backflow prevention mechanism for discharging a working fluid to the outside. FIG. 6(a) is a graph showing the relationship between the rotation angle and the timing of opening and closing the backflow prevention mechanism. FIG. 6(b) is a graph showing the relationship between the rotation angle and the involute angle of the sealing point. FIG. 7(a) is a diagram showing the state of the first and second laps immediately before discharge. FIG. 7(b) is a diagram showing the state of the first and second laps immediately after discharge. FIG. 8(a) is a cross-sectional view showing the structure of a second drive shaft included in a scroll fluid machine of a first modified example. FIG. 8(b) is a cross-sectional view showing the structure of a second drive shaft included in a scroll fluid machine of a second modified example. Fig. 9 is a cross-sectional view of a scroll fluid machine according to a third modified example. Fig. 10 is a diagram schematically showing a motor according to an embodiment.

[0021] Hereinafter, an embodiment of a scroll fluid machine according to the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicated explanations will be omitted.

[0022] The scroll fluid machine 1 of this embodiment shown in Fig. 1 can prevent backflow of the working fluid not only when stopped but also when in operation. As shown in Fig. 1, the scroll fluid machine 1 has, as its main components, a first drive shaft 2, a first scroll unit 3, a second drive shaft 4, a second scroll unit 5, and a controller 15. The scroll fluid machine 1 also has components such as a cooling mechanism, but these components are not shown in Fig. 1 etc.

[0023] As shown in Figures 2 and 3, the first drive shaft 2 is connected to the first motor 10. This first motor 10 may or may not be defined as a component of the scroll fluid machine 1. A first outer end 21 of the first drive shaft 2 is connected to a first motor shaft 10S of the first motor 10. In other words, the first drive shaft 2 is a component separate from the first motor shaft 10S. The controller 15 controls the start and stop of the first motor 10 by providing a command C1 to the first motor 10. The controller 15 may also control the rotation speed of the first motor 10 by providing the command C1 to the first motor 10.

[0024] The first inner end 22 of the first drive shaft 2 is connected to the first scroll unit 3. The first drive shaft 2 is rotatably supported by two bearings B1 and B2 between the first outer end 21 and the first inner end 22. The first scroll unit 3 rotates about an axis A2.

[0025] The first scroll unit 3 includes a first scroll housing 31 , a first scroll arm 32 , a first scroll end plate 33 , a pair of first wraps 341 , 342 , and a connecting unit 35 .

[0026] The first scroll housing 31 cooperates with the second scroll housing 51 (described later) to form a space for accommodating the first wraps 341, 342 and the second wraps 541, 542. The first scroll housing 31 has a first housing wall 311, a first housing peripheral wall 312, and a first drive shaft support 313. A cylindrical first drive shaft support 313 stands on the main surface 311a of the first housing wall 311. The first drive shaft support 313 includes a first support through-hole 313H extending from the end surface 313a to the back surface 311b of the first housing wall 311. The first drive shaft support 313 further includes a pair of bearing arrangement portions P1, P2. One bearing arrangement portion P1 is a recess provided in the end surface 313a of the first drive shaft support 313. One bearing B1 is arranged in one bearing arrangement portion P1. The other bearing arrangement portion P2 is a recess provided in the rear surface 311b of the first housing wall portion 311. The other bearing B2 is arranged in the other bearing arrangement portion P2.

[0027] The first inner end portion 22 of the first drive shaft 2 is fixed to the main surface 32a of the first scroll arm 32. A plurality of connecting units 35 are provided on the back surface 32b of the first scroll arm 32. A first scroll end plate 33 is connected to the first scroll arm 32 via the connecting units 35. One first wrap 341 is provided on the main surface 33a of the first scroll end plate 33, and the other first wrap 342 is provided on the back surface 33b of the first scroll end plate 33.

[0028] The second drive shaft 4 is connected to the second motor 20. This second motor 20 may also be defined as a component of the scroll fluid machine 1, or may not be defined as a component of the scroll fluid machine 1. A second outer end 41 of the second drive shaft 4 is connected to a second motor shaft 20S of the second motor 20. In other words, the second drive shaft 4 is a component separate from the second motor shaft 20S. The controller 15 controls the start and stop of the second motor 20 by providing a command C2 to the second motor 20. The controller 15 may also control the rotation speed of the second motor 20 by providing a command C2 to the second motor 20.

[0029] Furthermore, the controller 15 may control the rotational angle position of the second drive shaft 4 by providing a command C2 to the second motor 20. As will be described later, the scroll fluid machine 1 can switch between a state in which discharge of the working fluid is permitted and a state in which discharge of the working fluid is not permitted (backflow prevention state) depending on the rotational position of the second drive shaft 4. For example, when stopping the operation of the scroll fluid machine 1, the controller 15 may control the rotational position of the second drive shaft 4 so as to enter a state in which discharge of the working fluid is not permitted (backflow prevention state).

[0030] The second inner end 42 of the second drive shaft 4 is connected to the second scroll unit 5. The second drive shaft 4 is rotatably supported by two bearings B3 and B4 between the second outer end 41 and the second inner end 42. The second scroll unit 5 rotates about an axis A4. The axis A4 of the second drive shaft 4 is offset by a predetermined distance from the axis A2 of the first drive shaft 2. With this configuration, the first wraps 341 and 342 rotate about the axis A2, and the second wraps 541 and 542 rotate about the axis A4. As a result, the first wraps 341 and 342 and the second wraps 541 and 542 rotate synchronously with each other.

[0031] The second scroll unit 5 has a second scroll housing 51 , a pair of second scroll end plates 521 , 522 , and a pair of second wraps 541 , 542 .

[0032] The second scroll housing 51 has a second housing wall 511, a second housing peripheral wall 512, and a second drive shaft support 513. A hole 511P for introducing the working fluid is provided in the main surface 511a of the second housing wall 511. Furthermore, a cylindrical second drive shaft support 513 extends from the main surface 511a of the second housing wall 511. The second drive shaft support 513 includes a second support through-hole 511H extending from the outer end surface 513a to the back surface 511b of the second housing wall 511. The second drive shaft support 513 also includes a bearing arrangement portion P3. The bearing arrangement portion P3 is a recess provided on the back surface 511b of the second housing wall 511. A bearing B3 is disposed in the bearing arrangement portion P3. The second drive shaft support 513 also includes a seal arrangement portion Q3 (see FIG. 4). The seal arrangement portion Q3 is a recess provided in the bottom surface of the bearing arrangement portion P3. The seal E3 is arranged in the seal arrangement portion Q3. A small gap is provided between the end face of the bearing B3 and the end face of the seal E3.

[0033] As mentioned at the beginning, the scroll fluid machine 1 has a function of preventing backflow of the working fluid. The configuration for preventing backflow of the working fluid will be described in detail below. The configuration for preventing backflow of the working fluid will be referred to as a "backflow prevention mechanism 7." The backflow prevention mechanism 7 is composed of the second drive shaft 4 and a backflow prevention component 8.

[0034] 4, the second drive shaft 4 includes an axial hole 43 and a radial hole 44. The axial hole 43 and the radial hole 44 are connected to each other.

[0035] The axial hole 43 includes an end face opening 42aP (first opening) formed in the inner end face 42a of the second drive shaft 4. This end face opening 42aP is connected to a discharge port 52P formed in one of the second scroll end plates 521. In other words, the axial hole 43 can receive high-pressure working fluid from the discharge port 52P. The axial hole 43 extends from the inner end face 42a toward the outer end face 41a but does not reach the outer end face 41a. An axis A43 of the axial hole 43 coincides with the axis A4 of the second drive shaft 4.

[0036] The radial hole 44 includes a peripheral opening 4sP (second opening) formed in the outer peripheral surface 4s of the second drive shaft 4. The radial hole 44 is defined by the axis A44. The radial hole 44 extends in a direction perpendicular to the axis A4 of the second drive shaft 4, reaching a position where it intersects with the axis A4 of the second drive shaft 4, but does not reach the outer peripheral surface 4s on the opposite side. The radial hole 44 is connected to the axial hole 43 at a position where it intersects with the axis A4 of the second drive shaft 4. Therefore, the axial hole 43 and the radial hole 44 form a continuous through hole 4H (hole). When viewed in cross section, the axial hole 43 and the radial hole 44 are L-shaped.

[0037] When the second drive shaft 4 rotates, the circumferential opening 4sP of the radial hole 44 also rotates in response to the rotation of the second drive shaft 4. In other words, the member facing the circumferential opening 4sP changes in response to the rotation of the second drive shaft 4. The member facing the circumferential opening 4sP is the inner circumferential surface of the backflow prevention component 8.

[0038] <Backflow prevention component 8> The backflow prevention component 8 is cylindrical. The inner end surface 8b of the backflow prevention component 8 abuts against the end surface 513a of the second scroll housing 51. The backflow prevention component 8 has a component through-hole 8H that extends from the inner end surface 8b to the outer end surface 8a. The second drive shaft 4 is inserted through this component through-hole 8H. A bearing arrangement portion P4 and a seal arrangement portion Q4 are provided on the outer end surface 8a of the backflow prevention component 8. A bearing B4 is arranged in the bearing arrangement portion P4. A seal E4 is arranged in the seal arrangement portion Q4.

[0039] In this embodiment, the backflow prevention component 8 is described as being an independent component separate from the second scroll housing 51. However, the backflow prevention component 8 may also be configured as a part of the second scroll housing 51.

[0040] The backflow prevention component 8 includes a component communication hole 8P. The component communication hole 8P includes a peripheral surface opening 8sP provided on the outer peripheral surface 8s of the backflow prevention component 8. The component communication hole 8P extends in a direction intersecting the axis A4 of the second drive shaft 4. The component communication hole 8P is connected to a space formed by a communication portion 81, which will be described later. The component communication hole 8P is defined by the axis A8P.

[0041] As shown in Figures 5(a) and 5(b), the backflow prevention component 8 has the function of switching between a state S1 (see Figure 5(a)) in which the circumferential opening 4sP is closed and a state S2 (see Figure 5(b)) in which the circumferential opening 4sP is open. The backflow prevention component 8 includes a communication portion 81. The communication portion 81 is a recess provided in the inner end surface 8b. The backflow prevention component 8 includes a switch-close inner circumferential surface 81a, a switch-open inner circumferential surface 81b, a switch bottom surface 81c, and switch end surfaces 81d and 81e that define the communication portion 81. The communication portion 81 is surrounded by the switching closed inner surface 81a (first inner surface), the switching open inner surface 81b (second inner surface), the switching bottom surface 81c, the switching end surfaces 81d and 81e, the outer surface 4s of the second drive shaft 4, and the outer end surface 513a of the second scroll housing 51.

[0042] The inner diameter of the switching closed inner peripheral surface 81a is the same as the outer diameter of the second drive shaft 4. Therefore, the outer peripheral surface 4s of the second drive shaft 4 can come into contact with the switching closed inner peripheral surface 81a. In contrast, the inner diameter of the switching open inner peripheral surface 81b is larger than the outer diameter of the second drive shaft 4. Therefore, the outer peripheral surface 4s of the second drive shaft 4 cannot come into contact with the switching open inner peripheral surface 81b. A predetermined gap 8G is formed between the switching open inner peripheral surface 81b and the outer peripheral surface 4s of the second drive shaft 4.

[0043] 5A, when the circumferential opening 4sP of the second drive shaft 4 faces the switching closure inner circumferential surface 81a, the circumferential opening 4sP is blocked by the switching closure inner circumferential surface 81a. In other words, the circumferential opening 4sP is not connected to the gap 8G. When the circumferential opening 4sP is not connected to the gap 8G, the flow path from the discharge port 52P to the piping system 101 is blocked. As a result, even if the internal pressure of the scroll fluid machine 1 is lower than the internal pressure of the piping system 101, the working fluid in the piping system 101 does not flow back toward the scroll fluid machine 1.

[0044] 5B, when the circumferential opening 4sP of the second drive shaft 4 faces the switching open inner circumferential surface 81b, the circumferential opening 4sP is connected to the gap 8G. In the state where the circumferential opening 4sP is connected to the gap 8G, a flow path is formed from the discharge port 52P to the piping system 101. Therefore, high-pressure working fluid can be discharged from the discharge port 52P to the piping system 101.

[0045] Here, the switch-closing inner circumferential surface 81a is provided over a predetermined angle around the axis A4 of the second drive shaft 4, and the switch-opening inner circumferential surface 81b is provided over the remaining angle around the axis A4 of the second drive shaft 4. In other words, the period during which the second drive shaft 4 makes one rotation can be divided into a period during which the circumferential opening 4sP is closed (see FIG. 5(a)) and a period during which the circumferential opening 4sP is open (see FIG. 5(b)). The setting of each period may be set depending on the open / closed state of the discharge port 52P.

[0046] FIG. 6(a) is a graph showing the relationship between the rotation angle of the second drive shaft 4 and the open / closed state of the circumferential opening 4sP. The open / closed state of the circumferential opening 4sP can also be interpreted as the open / closed state of the discharge port 52P. FIG. 6(b) is a graph showing the relationship between the rotation angle and the involute angle of the sealing point S7P (see FIG. 7(a)). As shown in graph G62 of FIG. 6(b), the involute angle of the sealing point S7P changes from 240° to 60° during the period when the rotation angle of the second drive shaft 4 changes from 0° to 180°. During the period when the rotation angle of the second drive shaft 4 changes from 0° to 180°, the opening 4sP is in the open state (S2) during the period when the rotation angle of the second drive shaft 4 changes from 0° to 160°. In other words, during this period, the opening 4sP faces the switch-open inner circumferential surface 81b (see FIG. 5(b)). When the rotation angle of the second drive shaft 4 reaches 160 degrees (see point P62a), the state transitions from the open state (S2) to the closed state (S1) (see graph G61). That is, after this period has elapsed, the circumferential opening 4sP faces the switch-close inner circumferential surface 81a (see FIG. 5A). When the involute angle reaches 60 degrees (see point P62b), that is, when the rotation angle is 180 degrees, the involute angle transitions to 420 degrees (see point P62c).

[0047] Then, rotation continues. During the period when the rotation angle of the second drive shaft 4 changes from 180 degrees to 360 degrees, the involute angle of the sealing point S7P changes from 420 degrees to 240 degrees. During the period when the rotation angle of the second drive shaft 4 changes from 180 degrees to 360 degrees, the period from 180 degrees to 320 degrees is the closed state (S1) (see FIG. 5(a)). Then, when the rotation angle of the second drive shaft 4 reaches 320 degrees (see point P62d), the state transitions from the closed state (S1, see FIG. 5(a)) to the open state (S2, see FIG. 5(b)).

[0048] In this way, the closed state (S1, see FIG. 5(a)) and the open state (S2, see FIG. 5(b)) are switched between in accordance with the rotation angle of the second drive shaft 4. The rotation angle and the timing of opening and closing can be adjusted by the positions of the switching end faces 81d, 81e around the axis A4 of the second drive shaft 4.

[0049] <Effects> As described in Patent Document 2, there are several possible mechanisms for preventing backflow of the working fluid. For example, one approach is to provide a backflow prevention mechanism near the discharge port 52P of the scroll fluid machine 1. However, the area near the discharge port 52P is susceptible to the effects of high-temperature working fluid. Furthermore, the area is also susceptible to the effects of pulsation caused by the intermittent discharge of high-pressure working fluid from the scroll fluid machine 1. Due to this temperature and pulsation, it is difficult to provide a backflow prevention mechanism near the discharge port 52P. Therefore, another approach is to provide a check valve as a backflow prevention mechanism in the piping system 101 away from the discharge port 52P. However, because the check valve is far from the discharge port 52P, a delay occurs in the opening and closing operation of the check valve in response to pressure fluctuations. Therefore, the backflow of the working fluid cannot be prevented because the check valve cannot respond to the rapid fluctuations (pulsations) in the pressure discharged from the scroll fluid machine 1.

[0050] Therefore, the scroll fluid machine 1 of the present disclosure is provided with the following configuration, thereby being able to perform the function of preventing backflow of the working fluid even during operation.

[0051] The scroll fluid machine 1 includes a scroll mechanism 11 having spiral first wraps 341, 342 and spiral second wraps 541, 542 that revolve around an axis A4 relative to the first wraps 341, 342, a second drive shaft 4 that rotates around the axis A4 and revolves the second wraps 541, 542, and a backflow prevention mechanism 7 through which the second drive shaft 4 is inserted. The second drive shaft 4 is provided with an end surface opening 42aP that communicates with the interior of the scroll mechanism 11, a circumferential surface opening 4sP that opens in a direction intersecting the axis A4 and is formed on an outer circumferential surface 4s of the second drive shaft 4, and a through hole 4H that connects the end surface opening 42aP and the circumferential surface opening 4sP. The backflow prevention mechanism 7 has a communication section 81 that communicates with the outside of the scroll mechanism section 11 and that switches between a state in which the circumferential opening 4sP faces the scroll mechanism section 11 and a state in which the circumferential opening 4sP does not face the scroll mechanism section 11 as the second drive shaft 4 rotates.

[0052] The second drive shaft 4 of this scroll fluid machine 1 has a through hole 4H including an end face opening 42aP communicating with the interior of the scroll mechanism 11. This through hole 4H also includes a circumferential surface opening 4sP provided on the outer circumferential surface 4s of the second drive shaft 4. Therefore, the second drive shaft 4 can form a path communicating with the interior of the scroll mechanism 11. The scroll fluid machine 1 also has a backflow prevention mechanism 7 in which the second drive shaft 4 is disposed. The backflow prevention mechanism 7 has a communication portion 81 communicating with the outside of the scroll mechanism 11. This communication portion 81 switches between a state in which the circumferential surface opening 4sP faces the outside (S1) and a state in which the circumferential surface opening 4sP does not face the outside (S2) as the second drive shaft 4 rotates. With this configuration, it is possible to switch between a state in which the inside and outside of the scroll mechanism 11 are connected and a state in which the inside and outside of the scroll mechanism 11 are not connected, depending on the rotation of the second drive shaft 4. When the inside and outside of the scroll mechanism 11 are connected, it is possible to exchange working fluid between the scroll mechanism 11 and the outside. When the inside and outside of the scroll mechanism 11 are not connected, it is possible to prevent backflow of working fluid from the outside to the scroll mechanism 11.

[0053] The backflow prevention mechanism 7 has a switch-closed inner circumferential surface 81 a and a switch-open inner circumferential surface 81 b that face the circumferential opening 4 sP. With this configuration, it is possible to switch between a state in which the inside and outside of the scroll mechanism 11 are connected and a state in which the inside and outside of the scroll mechanism 11 are not connected, depending on the rotation of the second drive shaft 4.

[0054] The backflow prevention mechanism 7 has a switch-closed inner circumferential surface 81a that contacts the outer circumferential surface 4s of the second drive shaft 4, and a switch-open inner circumferential surface 81b that does not contact the outer circumferential surface 4s of the second drive shaft 4. With this configuration, during one rotation of the second drive shaft 4, the inside and outside of the scroll mechanism 11 can be disconnected from each other during the period when the circumferential opening 4sP faces the switch-closed inner circumferential surface 81a, and the inside and outside of the scroll mechanism 11 can be connected from each other during the period when the circumferential opening 4sP faces the switch-open inner circumferential surface 81b.

[0055] The backflow prevention mechanism 7 holds the bearings B3 and B4 that support the rotation of the second drive shaft 4. With this configuration, the second drive shaft 4 can be rotatably supported.

[0056] The scroll fluid machine 1 has seals E1 and E2 provided before and after the through hole 4H in the axial direction of the second drive shaft 4. With this configuration, leakage of the working fluid can be suppressed.

[0057] The scroll fluid machine 1 further includes a second motor 20 that applies a rotational driving force to the second drive shaft 4, and a controller 15 that alternately switches between an operation in which the second motor 20 rotates the second drive shaft 4 and an operation in which the second motor 20 stops the rotation of the second drive shaft 4. The controller 15 stops the rotation of the second drive shaft 4 in a state in which the circumferential surface opening 4sP faces the first inner circumferential surface. With this configuration, backflow of the working fluid from the outside to the scroll fluid machine 1 can be prevented when the operation of the scroll fluid machine 1 is stopped.

[0058] The scroll mechanism 11 includes a first scroll unit 3 including first wraps 341, 342 and connected to a first drive shaft 2, and a second scroll unit 5 including second wraps 541, 542 and connected to a second drive shaft 4 separate from the first drive shaft 2. With this configuration, a so-called spinning-type scroll fluid machine 1 can be configured.

[0059] The scroll fluid machine 1 includes a first motor 10 that provides a rotational driving force to the first drive shaft 2, and a second motor 20 that provides a rotational driving force to the second drive shaft 4. With this configuration, the rotational driving force can be provided to each of the first drive shaft 2 and the second drive shaft 4.

[0060] <Modifications> The scroll fluid machine of the present disclosure can be implemented in various forms, including the above-described embodiment, with various modifications and improvements made based on the knowledge of those skilled in the art. Furthermore, modifications can also be constructed by utilizing the technical matters described in the above-described embodiment. The configurations of the embodiments and the like may be used in appropriate combination.

[0061] <First Modification> A scroll fluid machine 1A of a first modification shown in FIG. 8( a) has a thermal insulation pipe 91 attached to the second drive shaft 4. The thermal insulation pipe 91 contacts the inner circumferential surface 43a of the axial hole 43. The thermal insulation pipe 91 extends from the inner end surface 42a of the second drive shaft 4 to a position overlapping with the radial hole 44. A bearing B3 is provided in this area. Considering the relative positions of the bearing B3 and the thermal insulation pipe 91, the thermal insulation pipe 91 can be said to be located on a thermal path from the high-temperature working fluid flowing through the axial hole 43 to the bearing B3. Therefore, the thermal insulation pipe 91 can prevent heat from being transferred from the high-temperature working fluid flowing through the axial hole 43 to the bearing B3 via the second drive shaft 4. As a result, the thermal influence on the bearing B3 is reduced, thereby maintaining the function of the bearing B3.

[0062] <Second Modification> From the perspective of protecting bearings B3 and B4 from heat, a scroll fluid machine 1B configuration according to a second modification shown in FIG. 8( b) may be adopted. The scroll fluid machine 1B according to the second modification has heat insulating rings 92A and 92B attached to the outer peripheral surface 4 s of the second drive shaft 4. The inner rings of bearings B3 and B4 are fitted so as to contact the outer peripheral surface 4 s of the heat insulating rings 92A and 92B. This configuration also allows the heat insulating rings 92A and 92B to be positioned on the heat path leading from the high-temperature working fluid flowing through the axial bore 43 to the bearings B3 and B4. Therefore, as with the first modification, the heat influence on bearings B3 and B4 is reduced, thereby maintaining the functionality of bearings B3 and B4.

[0063] 9 is a cross-sectional view of a scroll fluid machine 1C of a third modified example. The scroll fluid machine 1C of the third modified example does not include the backflow prevention component 8 that is included in the scroll fluid machine 1 of the first embodiment. The other configurations are the same as those of the scroll fluid machine 1 of the first embodiment.

[0064] More specifically, the scroll fluid machine 1C of the third modified example includes a scroll mechanism 11 having spiral first wraps 341, 342 and spiral second wraps 541, 542 that revolve around the axis A4 relative to the first wraps 341, 342, a second drive shaft 4 that rotates around the axis A4 to revolve the second wraps 541, 542, and a second motor 20 that applies a rotational driving force to the second drive shaft 4. The second drive shaft 4 is provided with an end surface opening 42aP that communicates with the interior of the scroll mechanism 11, a circumferential surface opening 4sP that opens in a direction intersecting the axis A4 and is formed on the outer circumferential surface 4s of the second drive shaft 4 between the scroll mechanism 11 and the second motor 20, and a through hole 4H that connects the end surface opening 42aP and the circumferential surface opening 4sP. The scroll fluid machine 1C includes the second motor 20 connected to the second drive shaft 4. The second drive shaft 4 discharges the working fluid discharged from the scroll mechanism 11 from a peripheral surface opening 4sP.

[0065] According to the scroll fluid machine 1C of the third modified example, the working fluid is always discharged regardless of the rotation angle of the second drive shaft 4. The circumferential surface opening 4sP is formed on the outer circumferential surface 4s of the second drive shaft 4, between the scroll mechanism 11 and the second motor 20. Therefore, the working fluid can be discharged without reaching the second motor 20. As a result, the influence of the state of the working fluid on the second motor 20 can be suppressed.

[0066] 10 is a schematic diagram of a motor 20D according to a fourth modification. The motor 20D includes a motor shaft 20D5 having an axial hole 43 and a radial hole 44 similar to those of the second drive shaft 4 of the first embodiment.

[0067] More specifically, motor 20D includes a motor shaft 20D1, a rotor 20D2 including a magnet that rotates together with motor shaft 20D1, a stator 20D3 that is disposed around rotor 20D2 and includes a coil, and a case 20D4 that houses rotor 20D2 and stator 20D3. Motor shaft 20D1 includes a motor shaft 20D5 (output shaft) that protrudes from case 20D4. Motor shaft 20D5 is provided with an axial hole 43 that includes an end face opening 42aP provided on an end face of motor shaft 20D5 and extends in the direction of axis A20 of motor shaft 20D1, and a radial hole 44 that communicates with axial hole 43, extends in a direction intersecting the rotation axis, and includes a circumferential surface opening 4sP formed on the outer circumferential surface.

[0068] The motor shaft portion 20D1 of the motor 20D includes an end face opening 42aP provided on the end face of the motor shaft 20D5 and an axial hole 43 extending in the direction of the axis A20 of the motor shaft portion 20D1. The axial hole 43 can receive working fluid from a scroll fluid machine 1 connected to the motor shaft portion 20D1. Furthermore, the motor shaft portion 20D1 includes a radial hole 44 that communicates with the axial hole 43, extends in a direction intersecting the axis A20, and includes a circumferential surface opening 4sP formed on the outer peripheral surface. The radial hole 44 allows the working fluid received in the axial hole 43 to be discharged to the outside. Because the radial hole 44 includes the circumferential surface opening 4sP formed on the outer peripheral surface, the received working fluid can be discharged without reaching the rotor portion 20D2. As a result, the influence of the state of the working fluid on the rotor portion 20D2 can be suppressed.

[0069] The present disclosure includes the following combinations:

[0070] The present disclosure is [1] "a scroll fluid machine comprising: a scroll mechanism having a first spiral wrap and a second spiral wrap that revolves relative to the first wrap around a rotation axis; a shaft that rotates around the rotation axis and revolves the second wrap; and a shaft arrangement portion into which the shaft portion is inserted, wherein the shaft portion is provided with a first opening that communicates with the inside of the scroll mechanism, a second opening that opens in a direction intersecting the rotation axis and is formed on the outer peripheral surface of the shaft portion, and a hole portion that connects the first opening and the second opening, and the shaft arrangement portion has a communication portion that communicates with the outside of the scroll mechanism and switches between a state in which the second opening faces the outer peripheral surface and a state in which the second opening does not face the outer peripheral surface by rotation of the shaft portion."

[0071] The present disclosure is [2] "A scroll fluid machine according to the above [1], wherein the shaft portion arrangement portion has a wall portion facing the second opening."

[0072] The present disclosure is [3] "A scroll fluid machine as described in the above [2], wherein the wall portion has a first inner circumferential surface that contacts the outer circumferential surface of the shaft portion and a second inner circumferential surface that does not contact the outer circumferential surface of the shaft portion."

[0073] The present disclosure is [4] "A scroll fluid machine according to the above [1] or [2], wherein the shaft portion arrangement portion holds a bearing that supports the rotation of the shaft portion."

[0074] The present disclosure is [5] "A scroll fluid machine described in any one of [1] to [3] above, having sealing members provided before and after the hole portion in the axial direction of the shaft portion."

[0075] The present disclosure is [6] "a scroll fluid machine as described in [3] above, further comprising: a drive unit that applies a rotational drive force to the shaft portion; and a control unit that switches between an operation in which the drive unit rotates the shaft portion and an operation in which the drive unit stops the rotation of the shaft portion, wherein the control unit stops the rotation of the shaft portion when the second opening faces the first inner circumferential surface."

[0076] The present disclosure is [7] "A scroll fluid machine according to any one of the above [1] to [6], wherein the scroll mechanism includes: a first driving scroll including the first wrap and connected to a first shaft portion that is the shaft portion; and a second driving scroll including the second wrap and connected to a second shaft portion that is different from the first shaft portion."

[0077] The present disclosure is [8] "The scroll fluid machine described in the above [7], further comprising: a first drive unit that applies a rotational drive force to the first shaft portion; and a second drive unit that applies a rotational drive force to the second shaft portion."

[0078] The present disclosure is [9] "A scroll fluid machine described in any one of [1] to [8] above, wherein an insulating member formed of a material having a thermal conductivity lower than that of the shaft portion is arranged on the inner surface of the hole portion."

[0079] The present disclosure is

[10] "A scroll fluid machine comprising: a scroll mechanism having a first spiral wrap and a second spiral wrap that revolves relative to the first wrap around a rotation axis; a shaft that rotates around the rotation axis and revolves the second wrap; and a drive unit that applies a rotational drive force to the shaft, wherein the shaft is provided with a first opening that communicates with the interior of the scroll mechanism, a second opening that opens in a direction intersecting the rotation axis and is formed on the outer peripheral surface of the shaft between the scroll mechanism and the drive unit, and a hole that connects the first opening and the second opening."

[0080] The present disclosure is

[11] "a motor comprising: a motor shaft; a rotor including a magnet that rotates together with the motor shaft; a stator disposed around the rotor and including a coil; and a case that houses the rotor and the stator, wherein the motor shaft includes an output end that protrudes from the case, and the output end is provided with: a first hole that includes a first opening provided on an end face of the output end and extends in the direction of the rotation axis of the motor shaft; and a second hole that communicates with the first hole, extends in a direction intersecting the rotation axis, and includes an opening formed on the outer circumferential surface."

[0081] 1, 1A, 1B, 1C...Scroll fluid machine, 11...Scroll mechanism part, 341, 342...First wrap, 541, 542...Second wrap, 4...Second drive shaft, 42aP...End face opening, 4s...Outer peripheral surface, 4sP...Peripheral surface opening, 4H...Through hole, 7...Backflow prevention mechanism, 81...Communicating part, A4...Axis.

Claims

1. A scroll fluid machine comprising: a scroll mechanism having a first spiral wrap and a second spiral wrap that revolves relative to the first wrap around a rotation axis; a shaft that rotates around the rotation axis and revolves the second wrap; and a shaft arrangement portion through which the shaft is inserted, wherein the shaft portion has a first opening that communicates with the inside of the scroll mechanism, a second opening that opens in a direction intersecting the rotation axis and is formed on the outer surface of the shaft portion, and a hole portion that connects the first opening and the second opening, and the shaft arrangement portion has a communication portion that communicates with the outside of the scroll mechanism and switches between a state in which the second opening faces the shaft and a state in which the second opening does not face the shaft as the shaft portion rotates.

2. A scroll fluid machine according to claim 1, wherein the shaft portion placement portion has a wall portion facing the second opening.

3. A scroll fluid machine according to claim 2, wherein the wall portion has a first inner peripheral surface that contacts the outer peripheral surface of the shaft portion, and a second inner peripheral surface that does not contact the outer peripheral surface of the shaft portion.

4. A scroll fluid machine according to claim 1 or 2, wherein the shaft portion arrangement portion holds a bearing that supports the rotation of the shaft portion.

5. A scroll fluid machine according to any one of claims 1 to 3, further comprising seal members provided before and after the hole in the axial direction of the shaft portion.

6. A scroll fluid machine as described in claim 3, further comprising: a drive unit that applies a rotational drive force to the shaft portion; and a control unit that switches between an operation in which the drive unit rotates the shaft portion and an operation in which the drive unit stops the rotation of the shaft portion, wherein the control unit stops the rotation of the shaft portion when the second opening faces the first inner circumferential surface.

7. A scroll fluid machine as described in claim 1, wherein the scroll mechanism includes a first driving scroll including the first wrap and connected to a first shaft portion which is the shaft portion, and a second driving scroll including the second wrap and connected to a second shaft portion different from the first shaft portion.

8. A scroll fluid machine according to claim 7, further comprising: a first drive unit that applies a rotational drive force to the first shaft unit; and a second drive unit that applies a rotational drive force to the second shaft unit.

9. A scroll fluid machine as described in claim 1, wherein an insulating member made of a material having a thermal conductivity lower than that of the shaft portion is disposed on the inner peripheral surface of the hole portion.

10. A scroll fluid machine comprising: a scroll mechanism having a first spiral wrap and a second spiral wrap that revolves relative to the first wrap around a rotation axis; a shaft that rotates around the rotation axis and revolves the second wrap; and a drive unit that applies a rotational driving force to the shaft, wherein the shaft is provided with a first opening that communicates with the interior of the scroll mechanism, a second opening that opens in a direction intersecting the rotation axis and is formed on the outer surface of the shaft between the scroll mechanism and the drive unit, and a hole that connects the first opening and the second opening.

11. A motor comprising: a motor shaft; a rotor including a magnet that rotates together with the motor shaft; a stator arranged around the rotor and including a coil; and a case that houses the rotor and stator, wherein the motor shaft includes an output end that protrudes from the case, and the output end is provided with a first hole that includes a first opening provided on an end face of the output end and extends in the direction of the rotational axis of the motor shaft, and a second hole that communicates with the first hole, extends in a direction intersecting the rotational axis, and includes an opening formed on the outer peripheral surface.

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