JP7619981B2 - Scroll compressor and heat pump water heater - Google Patents

Description

The present invention relates to scroll compressors and heat pump water heaters used in refrigeration cycle devices such as air conditioning, hot water supply, and refrigeration.

Scroll compressors used in refrigeration cycle devices for air conditioning, hot water supply, refrigeration, etc. include those described in Japanese Patent No. 6143862 (Patent Document 1). This Patent Document 1 describes a scroll compressor that includes a fixed scroll with a spiral wrap standing on a base plate, an orbiting scroll with a spiral wrap standing on an end plate that engages with the fixed scroll and orbits to form a suction chamber or a compression chamber, a back pressure chamber that applies a pressing force to the orbiting scroll against the fixed scroll, a back pressure valve for adjusting the back pressure of the back pressure chamber, a back pressure valve inlet passage that connects the inlet side of the back pressure valve to the back pressure chamber, and a back pressure valve outlet passage that connects the outlet side of the back pressure valve to the suction chamber or the compression chamber.

It also describes that at least a part of the flow passage outlet of the back pressure valve outflow passage to the suction chamber or compression chamber is formed closer to the tooth bottom than the position of the wrap tooth tip of the fixed scroll, and that by forming the cross-sectional area of the flow passage outlet side of the back pressure valve outflow passage larger than the cross-sectional area of the flow passage inlet side, a part of the flow passage outlet of the back pressure valve outflow passage is made closer to the tooth bottom than the position of the wrap tooth tip of the fixed scroll.

Patent No. 6143862

Patent Document 1 describes how the cross-sectional area of the back pressure valve outlet passage (oil supply path) is made larger than the cross-sectional area of the flow passage inlet, so that oil flowing from the back pressure chamber into the suction chamber or compression chamber is supplied not only to the wrap tooth tip side of the fixed scroll, but also to the gap between the fixed scroll tooth base and the wrap tooth tip of the orbiting scroll.

However, due to structural constraints of the scroll compressor, even if the cross-sectional area of the oil supply path on the outlet side of the flow passage is made large, if the suction port of the scroll compressor is on the path of the oil flowing from the outlet of the flow passage to the suction chamber, the axial gas flow sucked in from the suction port will suppress the flow of oil toward the wrap tooth bottom side of the fixed scroll, and oil cannot be sufficiently supplied to the wrap tooth bottom side of the fixed scroll. This causes an issue of insufficient oil supply to the gap between the wrap tooth bottom of the fixed scroll and the wrap tooth tip of the orbiting scroll, reducing sealing performance and reducing volumetric efficiency, which leads to a decrease in the efficiency of the scroll compressor.

The object of the present invention is to provide a scroll compressor and a heat pump water heater that can ensure oil supply to the wrap tooth bottom side of the fixed scroll and improve the sealing of the gap between the wrap tooth bottom of the fixed scroll and the wrap tooth tip of the orbiting scroll, thereby improving efficiency.

In order to achieve the above object, the present invention provides a fixed scroll having a spiral fixed wrap standing on a fixed end plate, an orbiting scroll having a spiral orbiting wrap standing on a rotating end plate and meshing with the fixed scroll to perform orbital motion, a suction chamber and a compression chamber formed by meshing the fixed scroll and the orbiting scroll with each other, a crankshaft for orbiting the orbiting scroll, an orbiting bearing provided in the orbiting boss of the orbiting scroll for supporting the orbiting scroll axially movable and rotatably relative to the eccentric pin of the crankshaft, an internal space of the orbiting boss to which lubricating oil stored in a sealed container is introduced and which is held at a pressure close to the discharge pressure, a back pressure chamber provided on the back surface of the orbiting scroll and closer to the outer periphery than the internal space of the orbiting boss and which is held at a pressure between the discharge pressure and the suction pressure, and a fixed end plate of the fixed scroll. A scroll compressor having an intake port provided on the outer periphery of the plate and through which refrigerant gas is guided from a suction pipe, the scroll compressor is characterized in that it is provided with an intake section provided on the fixed end plate between the intake port and the suction chamber, a wall member provided on the opposite side of the intake port from the suction pipe and deflecting the flow of refrigerant gas from the suction pipe to an oblique flow, an oil supply recess provided on the outer periphery of the rotating end plate and through which oil from the back pressure chamber is guided, an intake groove provided on the fixed end plate and guiding the oil from the oil supply recess to the intake section side, and a tapered portion formed on the outlet side of the intake groove for discharging at least a portion of the oil from the intake groove to the tooth tip side of the rotating wrap, and the intake section side opening of the intake groove is opened on the back side of the wall member, and the wall member is configured to form an umbrella of oil flowing out of the suction groove against the refrigerant gas flowing in from the suction pipe.

Other features of the present invention include a fixed scroll having a spiral-shaped fixed wrap standing on a fixed end plate, an orbiting scroll having a spiral-shaped orbiting wrap standing on a orbiting end plate and meshing with the fixed scroll to perform orbital motion, a suction chamber and a compression chamber formed by meshing the fixed scroll and the orbiting scroll with each other, a crankshaft for orbiting the orbiting scroll, an orbiting bearing provided in the orbiting boss of the orbiting scroll for supporting the orbiting scroll axially movable and rotatable relative to the eccentric pin of the crankshaft, a space in the orbiting boss into which lubricating oil stored in a sealed container is introduced and the pressure in the orbiting boss is close to the discharge pressure, and A scroll compressor having a back pressure chamber that is located on the outer periphery of the space inside the rotating boss and has a pressure between the discharge pressure and the suction pressure, and an intake port that is located on the outer periphery of the fixed end plate of the fixed scroll and through which refrigerant gas is guided from a suction pipe, and the compressor has a suction section that is located on the fixed end plate between the suction port and the suction chamber, a wall member that is located on the opposite side of the suction pipe at the suction port and deflects the flow of refrigerant gas from the suction pipe to an oblique flow, an oil supply recess that is located on the outer periphery of the rotating end plate and through which oil from the back pressure chamber is guided, and an oil supply path that is located on the fixed end plate and discharges the oil from the oil supply recess to the suction port on the upstream side of the wall member.

Another feature of the present invention is that it is a heat pump water heater that includes a heat pump unit that heats up hot water and a hot water tank unit that stores hot water, the heat pump unit including a scroll compressor, a water-refrigerant heat exchanger that exchanges heat between the high-temperature, high-pressure refrigerant discharged from the scroll compressor and water, which is the medium to be heated, an expansion means that expands the refrigerant that flows out of the water-refrigerant heat exchanger to a low-temperature, low-pressure refrigerant, and an air-side heat exchanger that evaporates the low-temperature, low-pressure refrigerant that flows out of the expansion means, and the scroll compressor is a scroll compressor as described above.

The present invention has the effect of providing a scroll compressor and a heat pump water heater that can ensure oil supply to the wrap tooth bottom side of the fixed scroll and improve the sealing of the gap between the wrap tooth bottom of the fixed scroll and the wrap tooth tip of the orbiting scroll, thereby improving efficiency.

1 is a vertical cross-sectional view showing a first embodiment of a scroll compressor according to the present invention. 4 is a bottom view of the fixed scroll, showing a state in which the orbiting scroll is disposed on the fixed scroll. FIG. FIG. 2 is a plan view of the orbiting scroll shown in FIG. 1 . 4 is a cross-sectional view taken along line HH in FIG. 3. 3 is a cross-sectional view taken along line J-J in FIG. 2. FIG. 2 is a partially enlarged vertical cross-sectional view of the back pressure valve and its vicinity surrounded by a portion S in FIG. 1 . FIG. 7 is a diagram for explaining a second embodiment of a scroll compressor according to the present invention, and corresponds to FIG. 5 . FIG. 11 is a diagram for explaining a third embodiment of the present invention, and is a system schematic diagram of a heat pump water heater.

Below, specific examples of the scroll compressor of the present invention will be described with reference to the drawings. Note that in each drawing, parts with the same reference numerals indicate the same or corresponding parts.

A scroll compressor according to a first embodiment of the present invention will be described with reference to FIGS.
First, the overall configuration of the scroll compressor of the present embodiment will be described with reference to Figures 1 and 2. Figure 1 is a vertical sectional view showing a scroll compressor according to a first embodiment of the present invention, and Figure 2 is a bottom view of a fixed scroll showing a state in which an orbiting scroll is disposed on the fixed scroll.

The scroll compressor 1 is configured by accommodating a compression mechanism section 1A, a motor section 7, and the like in a sealed container 8.
The compression mechanism 1A has a compression chamber 10 formed by engaging a rotating scroll 3 with a fixed scroll 2 fixed to a frame 4, and the rotation of the motor unit 7 causes the rotating scroll 3 to orbit via a crankshaft (rotating shaft) 6, thereby reducing the volume of the compression chamber 10 and performing a compression operation.

As a result of this compression operation, the working fluid (refrigerant) is sucked from the suction pipe 12 through the suction port 2s into the suction chamber 16 (see Figure 2), and the sucked working fluid undergoes a compression stroke in the compression chamber 10 before being discharged from the discharge port 2d into the discharge space 11, which is the fixed back chamber in the sealed container 8. The working fluid discharged into this discharge space 11 flows through a passage (not shown) formed on the outer periphery of the fixed scroll 2 and the outer periphery of the frame 4 to the motor chamber 9 side, and is then discharged from the discharge pipe 13 to the outside of the sealed container 8.

The fixed scroll 2 comprises a fixed end plate 2a, a fixed wrap 2b that is spirally attached to the fixed end plate 2a, and a support portion 2c that is located on the outer periphery of the fixed end plate 2a, has a fixed end plate surface 2u that is approximately the same height as the tip surface of the fixed wrap 2b, and is cylindrically provided to surround the fixed wrap 2b. The surface of the fixed end plate 2a on which the fixed wrap 2b is attached is called the tooth bottom because it is between the fixed wraps 2b.

The fixed mirror plate surface 2u is a sliding surface where the support portion 2c of the fixed scroll 2 comes into contact with the rotating mirror plate 3a of the rotating scroll 3. The support portion 2c of the fixed scroll 2 is fixed to the frame 4 by bolts or the like, and the frame 4, which is integrally joined to the fixed scroll 2, is fixed to the sealed container 8 by a fixing means such as welding.

The orbiting scroll 3 is disposed opposite the fixed scroll 2, and the fixed wrap 2b of the fixed scroll 2 and the orbiting wrap 3b of the orbiting scroll 3 are meshed together to be orbitable within the frame 4. The orbiting scroll 3 has a spiral orbiting wrap 3b erected from the tooth bottom, which is the surface of the disk-shaped orbiting mirror plate 3a, and an orbiting boss portion (boss portion) 3c provided in the center of the back surface of the orbiting mirror plate 3a. In addition, the surface of the outer periphery of the orbiting mirror plate 3a that comes into contact with the fixed scroll 2 is the orbiting mirror plate upper surface 3a1 of the orbiting scroll 3 (see FIG. 3).

The tip (wrap tooth tip) of the orbiting wrap 3b of the orbiting scroll 3 is configured to face the tooth bottom of the fixed scroll 2 with a small gap. Similarly, the tip (wrap tooth tip) of the fixed wrap 2b of the fixed scroll 2 is also configured to face the tooth bottom of the orbiting scroll 3 with a small gap.

The bottom of the sealed container 8, which houses the compression mechanism 1A and the motor 7, is provided with an oil reservoir 8d for storing lubricating oil (hereinafter simply referred to as oil) as refrigeration oil. The motor 7 is composed of a rotor 7a and a stator 7b, and the crankshaft 6 is fixed integrally to the rotor 7a. The crankshaft 6 is rotatably supported by the frame 4 via a main bearing 14.

The tip of the crankshaft 6 is provided with an eccentric pin portion (eccentric pin portion) 6a, which is inserted into a revolving bearing 15 provided in the revolving boss portion 3c of the revolving scroll 3, so that the revolving scroll 3 can revolve with the rotation of the crankshaft 6.

The central axis of the orbiting scroll 3 is offset by a predetermined distance from the central axis of the fixed scroll 2. 5 is an Oldham ring for orbiting the orbiting scroll 3 relative to the fixed scroll 2 while restraining it from rotating on its axis.

The sealed container 8 is composed of a central cylindrical body 8a, a lid cap 8b that closes the upper part of the body 8a, and a bottom cap 8c that closes the lower part of the body 8a. 30 is a power terminal provided on the lid cap 8b. In addition, a counterweight 35 is provided on the upper part of the rotor 7a, and a counterweight 36 is provided on the lower part of the rotor 7a.

25 is a secondary bearing that supports the lower part of the crankshaft 6. This secondary bearing 25 includes a bearing bush 25a and a secondary bearing housing 25b that houses the bearing bush 25a. The secondary bearing housing 25b is fixed to a secondary frame 26 that is fixed to the lower side of the sealed container 8.

When the crankshaft 6 is rotated by the motor unit 7, the orbiting scroll 3 orbits with a predetermined orbital radius around the central axis of the fixed scroll 2. As a result, the refrigerant (refrigerant gas) of the refrigeration cycle flows in from the suction pipe 12, and flows from the suction port 2s formed in the fixed scroll 2 through the suction section 17 shown in Figure 2 into the suction chamber 16 formed by the fixed wrap 2b and the orbiting wrap 3b. The suction section 17 is formed between the suction port 2s and the suction chamber 16, and is a space for guiding the refrigerant gas (inflow gas) from the suction port 2s to the suction chamber 16.

Refrigerant gas is taken into the compression chamber 10 from the suction chamber 16, and as the orbiting scroll 3 orbits, the volume of the compression chamber 10 decreases and the refrigerant gas is compressed. The compressed refrigerant gas is discharged from the discharge port 2d into the discharge space 11, and then flows to the motor chamber 9 side. During this process, the oil contained in the refrigerant is separated and accumulates in the oil storage section 8d. The refrigerant from which the oil has been separated flows out from the discharge pipe 13 to the condenser side of the refrigeration cycle of a heat pump water heater, air conditioner, etc.

The flow of oil in the oil reservoir 8d will now be described. An oil supply pipe 6c is provided at the lower end of the crankshaft 6, and the lubricating oil stored in the oil reservoir 8d at the bottom of the sealed container 8 is at discharge pressure. This lubricating oil under discharge pressure flows in from the oil supply pipe 6c and passes through an oil supply hole 6b formed in the crankshaft 6 so as to penetrate in the axial direction, before being sent to the swivel boss space (swivel bearing chamber) 19, which is the space within the swivel boss 3c at the upper end of the pin 6a.

A portion of the lubricating oil flowing through the oil supply hole 6b is supplied to the auxiliary bearing 25 and the main bearing 14 through a horizontal hole provided in the crankshaft 6, and the oil that lubricates the auxiliary bearing 25 returns to the oil reservoir 8d at the bottom of the sealed container 8. The oil that lubricates the main bearing 14 returns to the oil reservoir 8d or flows into the back pressure chamber 18.

Most of the remaining lubricating oil flowing through the oil supply hole 6b reaches the swivel boss space (swivel bearing chamber) 19 at the upper end of the eccentric pin 6a, and lubricates the swivel bearing 15 through the oil groove provided on the outer circumferential surface of the eccentric pin 6a. This lubricating oil then flows into the back pressure chamber 18. Oil at the discharge pressure of the oil storage section 8d enters the swivel boss space 19, then reduces its pressure by passing through the swivel bearing 15, and flows to the suction side of the compression mechanism section 1A and the compression chamber 10, so that the pressure in the back pressure chamber 18 is between the discharge pressure and the suction pressure (intermediate pressure). The pressure in the swivel boss space 19 is close to the discharge pressure.

The lubricating oil that enters the back pressure chamber 18 lubricates the Oldham ring 5, lubricates the sliding parts between the fixed scroll 2 and the orbiting scroll 3, and seals the gaps at the tips of the wraps 2b and 3b.

In this embodiment, a portion of the lubricating oil that flows into the back pressure chamber 18 is supplied to the suction section 17 via an oil supply pocket (oil supply recess) 3d formed on the outer periphery of the rotating head plate 3a of the rotating scroll 3, and is configured to flow from here to the suction chamber 16 side.

The remainder of the lubricating oil that has flowed into the back pressure chamber 18 is configured to flow to the compression chamber 10 side via a compression chamber oil supply passage 28 having a back pressure valve 27 .
The oil in the back pressure chamber 18 flows into the suction chamber 16 and the compression chamber 10 to lubricate the sliding surfaces between the fixed scroll 2 and the orbiting scroll 3, the sliding surfaces between the fixed wrap 2b and the orbiting wrap 3b, and the gaps between the wrap tips, and is also used for sealing between the compression chambers, etc.

In FIG. 1, 21 is a check valve provided below the suction port 2s, which prevents the compressed refrigerant in the compression chamber 10 from flowing to the suction pipe 12 when the motor unit 7 stops. As shown in FIG. 1 and FIG. 2, an arc-shaped suction groove 2r is formed on the outer periphery of the fixed scroll 2, which is intermittently connected to the oil supply pocket 3d and is constantly connected to the suction unit 17. The outlet side of this suction groove 2r is formed in a tapered portion 2k, and the opening of this tapered portion 2k is provided on the lower side (back side) of the check valve (wall member) 21.

2e shown in FIG. 1 is a bypass hole formed in the fixed end plate 2a of the fixed scroll 2. As shown in FIG. 2, the bypass hole 2e is provided in the compression chamber 10 at the tooth bottom between the fixed wraps 2b and close to the discharge port 2d, and in this example, four bypass holes 2e are provided at positions that open to the inner line side compression chamber and the outer line side compression chamber of the orbiting wrap 3b. Also, as shown in FIG. 1, each bypass hole 2e is provided with a bypass valve 22, which is pressed by a spring 38 provided on a stopper 37. When the pressure of the compression chamber 10 to which the bypass hole 2e is open becomes higher than the pressure of the discharge space 11, resulting in an overcompression condition, and the force due to the pressure difference becomes greater than the pressing force of the spring 38, the bypass valve 22 opens, and the refrigerant gas in the compression chamber 10 is bypassed and discharged to the discharge space 11.

Figure 2 is a diagram explaining the meshing state between the fixed scroll 2 and the orbiting scroll 3. For the orbiting scroll 3, the orbiting wrap 3b is shown in cross section, and the orbiting head edge 3a2, which corresponds to the outer periphery of the orbiting head 3a of the orbiting scroll 3, is shown as a thin-line circle.

As shown in FIG. 2, multiple crescent-shaped compression chambers 10 (inner-side compression chambers and outer-side compression chambers) are formed between the fixed wrap 2b and the orbiting wrap 3b, and when the orbiting scroll 3 is orbited, the volume of each compression chamber 10 is continuously reduced as it moves toward the center.

16 is the suction chamber, which is the space in the process of sucking in the fluid. This suction chamber 16 becomes the compression chamber 10 when the phase of the orbiting motion of the orbiting scroll 3 advances and the trapping of the fluid is completed.

As shown in Figures 1 and 2, the portion of the fixed end plate 2a forming the suction section 17 is configured as an inclined portion 2t (see Figure 5) so that it is inclined (a diagonal flow path) from the suction port 2s portion below the suction pipe 12 toward the suction chamber 16. That is, the suction section 17 is formed so that it widens from the suction port 2s portion toward the downstream side. In addition, the check valve 21 is provided at the bottom of the suction port 2s, and this check valve 21 acts as a flow wall (wall member) and also has the effect of directing the flow toward the suction section 17. With these configurations, the refrigerant gas flowing in from the suction pipe 12 is configured to flow diagonally from the suction port 2s toward the suction section 17. In addition, the discharge port 2d is drilled near the center of the volute of the fixed end plate 2a of the fixed scroll 2.

Next, the configuration of the portion that supplies a portion of the oil in the back pressure chamber 18 to the suction portion 17 via the oil supply pocket 3d will be described with reference to Figures 3 to 5, as well as Figures 1 and 2. Figure 3 is a plan view of the orbiting scroll shown in Figure 1, Figure 4 is a cross-sectional view taken along line H-H in Figure 3, and Figure 5 is a cross-sectional view taken along line J-J in Figure 2.

In Figures 3 and 4, 3a1 is the upper surface (upper surface of the rotating mirror plate) of the rotating scroll 3, which becomes the thrust surface (rotating thrust surface) when the rotating scroll 3 is pressed against the fixed scroll 2. 3a2 is the outer peripheral edge of the rotating mirror plate 3a, which is called the rotating mirror plate edge. 3a3 is the lower surface (lower surface of the rotating mirror plate) of the rotating mirror plate 3a, and the back pressure chamber 18 is formed below this lower surface 3a3 of the rotating mirror plate.

A spiral-shaped orbiting wrap 3b is erected on the upper surface 3a1 of the orbiting mirror plate. A round oil supply pocket 3d is formed on the outer periphery of the upper surface 3a1 of the orbiting mirror plate, into which the oil from the back pressure chamber 18 flows and serves as an oil reservoir. In addition, 15 in FIG. 4 is an orbiting bearing, and 19 is an internal space of the orbiting boss (orbiting bearing chamber), which is a space formed between the upper surface of the pin portion 6a of the crankshaft 6 and the orbiting scroll.

As shown in FIG. 2, the oil supply pocket 3d is configured to trace a trajectory in the direction of the orbiting motion indicated by the arrow 32 within the sweep region 31 in conjunction with the orbiting motion of the orbiting scroll 3, and to intermittently communicate with the back pressure chamber 18 (see FIG. 1) and the suction groove 2r that communicates with the suction chamber 16.

When the oil supply pocket 3d is connected to the back pressure chamber 18, the oil in the back pressure chamber 18 (pressure is intermediate between the discharge pressure and the suction pressure) is stored in the oil supply pocket 3d. When the oil supply pocket 3d is connected to the suction groove 2r (pressure is suction pressure) with the orbiting motion of the orbiting scroll 3, the oil in the oil supply pocket 3d flows into the suction chamber 16 through the suction groove 2r due to the pressure difference. By repeating this operation with the orbiting motion of the orbiting scroll 3, the oil in the back pressure chamber 18 is transferred sequentially to the suction chamber 16. By adjusting the volume and number of the oil supply pockets 3d, it is possible to arbitrarily adjust the amount of oil supplied from the back pressure chamber 18 to the suction chamber 16.

2 and 3, the oil supply pocket (oil supply recess) 3d is formed in a round hole (circular shape), but this is not limited thereto, and the oil supply pocket 3d may be a shallow slit (groove). By making the oil supply pocket 3d slit-shaped, it is possible to not only intermittently communicate with the back pressure chamber, but also to constantly communicate with the back pressure chamber 18 and the suction section 17. Even if a slit-shaped communication groove (oil supply recess) that constantly communicates the back pressure chamber 18 and the suction groove 2r is used instead of the oil supply pocket 3d, the oil in the back pressure chamber 18 can flow into the suction chamber 16 due to the pressure difference between the back pressure chamber 18 and the suction section 17. The amount of oil supply can also be adjusted by adjusting the depth, width, length, or number of the slit-shaped communication groove.

Next, the configuration of the oil supply path that supplies oil from the back pressure chamber 18 to the suction portion 17 by the orbiting scroll 3 having the oil supply pocket 3d will be described using FIG. 5 while referring to FIG.
As the orbiting scroll 3 orbits, the oil supply pocket 3d orbits in a direction indicated by an arrow 32 in a predetermined sweep area 31, as shown in Fig. 2. The fixed scroll 2 is provided with a suction groove 2r extending from the sweep area 31 of the oil supply pocket 3d toward the suction portion 17. Furthermore, an annular recess 24 and a bay-shaped recess 23, which are always in communication with the back pressure chamber 18 (see Fig. 1) and hold oil, are formed on the outer periphery of the fixed wrap 2b of the fixed scroll 2. The bay-shaped recess 23 is provided at a position overlapping with a part of the orbital motion range (sweep area) of the oil supply pocket 3d formed in the orbiting scroll.

Therefore, there are moments when the oil supply pocket 3d overlaps with the suction groove 2r and the bay-shaped recess 23. The bay-shaped recess 23 and the suction groove 2r are not always in communication with each other via the oil supply pocket 3d. Instead, in synchronization with the orbiting motion of the orbiting scroll 3, the oil supply pocket 3d draws in oil when it faces the bay-shaped recess 23, and discharges oil from the suction groove 2r to the suction section 17 when it faces the suction groove 2r.

The amount of oil supplied per revolution of the orbiting scroll 3 is limited by the volume of the oil supply pocket 3d, which prevents excess oil from being supplied to the suction section 17. In this way, the oil supply pocket 3d supplies only a small amount of oil from the back pressure chamber 18 to the suction section 17, and the remaining oil is supplied to the compression chamber 10 via the compression chamber oil supply passage 28.

As shown in Figures 2 and 5, the opening of the suction groove 2r on the suction section 17 side opens to the lower side (back side) of the check valve (wall member) 21, and is located at a position where the check valve 21 becomes an umbrella of oil discharged from the suction groove 2r. In addition, the outlet side of the suction groove 2r is formed into a tapered portion 2k, and as shown in Figure 5, the oil discharged from the suction groove 2r to the suction section 17 is configured to flow not only horizontally but also upward.

In other words, the oil discharged from the tapered portion 2k is configured to be sufficiently supplied not only to the bottom side of the orbiting wrap 3b (the tip side of the fixed wrap 2b) but also to the tip side of the orbiting wrap 3b (the bottom side of the fixed wrap 2b).

However, we found that simply forming the outlet side of the suction groove 2r into a tapered portion 2k would push the oil downwards by the flow of refrigerant (flow of inflow gas G) sucked in from the suction pipe 12, and would not provide enough oil to the tooth tip side of the orbiting wrap 3b (tooth bottom side of the fixed wrap 2b). Therefore, in this embodiment, the outlet side of the suction groove 2r is formed into a tapered portion 2k, and the opening on the suction section 17 side of the suction groove 2r is opened to the lower side of the check valve 21, so that the check valve 21 becomes an umbrella for the oil flowing out of the suction groove 2r.

By configuring as in this embodiment, the oil discharged from the tapered portion 2k can be prevented from being pressed downward by the inflow gas from the suction pipe 12. Therefore, the oil discharged from the tapered portion 2k can be sufficiently supplied to the tooth tip side of the orbiting wrap 3b (the tooth bottom side of the fixed wrap 2b). This improves lubrication in the suction chamber 16 and the compression chamber 10 and also improves sealing properties, thereby preventing leakage of the working fluid during compression, thereby improving the efficiency of the scroll compressor.

In this embodiment, the opening end of the tapered portion 2k is located at the bottom near the center of the check valve 21. That is, the opening end of the tapered portion 2k is located at a position such that the upward flow of the oil discharged from the tapered portion 2k causes the check valve 21 to function as an umbrella against the gas flow flowing in from the suction port 2s, and oil is sufficiently supplied to the tooth tip side of the swirling wrap 3b (the tooth bottom side of the fixed wrap 2b). For example, it is preferable to configure the check valve 21 so that a portion with a length of 40 to 60% of the diameter functions as an umbrella for the oil discharged from the tapered portion 2k.

In addition, if the radial position of the oil supply pocket 3d of the orbiting scroll 3 is set to be approximately the same as the radial position of the suction port 2s provided in the fixed scroll 2, the suction groove 2r can be formed in an arc shape along the fixed wrap 2b as shown in Figure 2, making it easier to manufacture and more compact.

The outlet side of the suction groove 2r is formed as a tapered section 2k, but instead of the tapered section 2k, it may be formed as a taper with one or more fine steps. By making the tapered section 2k a step section with one or more steps in this way, the flow of the discharged oil can be made turbulent, promoting the diffusion action.

In this embodiment, the case where the check valve 21 is provided has been described, but if the check valve is not provided, the same effect can be obtained by providing a wall member that acts as an umbrella for the oil discharged from the tapered portion 2k. This wall member, like the check valve 21, should be provided so that the flow of gas flowing in from the suction pipe 12 flows obliquely from the suction port 2s toward the suction portion 17.

Next, the configuration of the compression chamber oil supply passage 28 shown in Fig. 1 will be described in detail with reference to Fig. 1 and Fig. 2, and with reference to Fig. 6. Fig. 6 is a partially enlarged vertical cross-sectional view of the back pressure valve 27 and its vicinity surrounded by the portion S in Fig. 1.
First, a description will be given of the function of the back pressure chamber 18. The back pressure chamber 18 is formed as a space surrounded by the fixed scroll 2, the orbiting scroll 3, and the frame 4, and oil is stored in this back pressure chamber 18 as described above.

In the scroll compressor 1, the compression action generates an axial force (pull-apart force) that tries to pull the fixed scroll 2 and the orbiting scroll 3 apart from each other. When this axial force causes the two scrolls to be pulled apart, a phenomenon known as the orbiting scroll 3 separation, the airtightness of the compression chamber 10 deteriorates, reducing the compressor efficiency.

Therefore, a back pressure chamber 18 is provided on the back side of the orbiting head plate 3a of the orbiting scroll 3, where the pressure is between the discharge pressure and the suction pressure, and the pressure (back pressure) of this back pressure chamber 18 cancels the separating force and presses the orbiting scroll 3 against the fixed scroll 2. If the pressing force is too large at this time, the sliding loss between the orbiting head plate upper surface 3a1 (see Figure 4) of the orbiting scroll 3 and the fixed head plate surface 2u of the fixed scroll 2 increases, and the compressor efficiency decreases.

In other words, there is an optimal value for the back pressure; if it is too low, the compression chamber will not be tightly sealed, increasing thermal fluid loss, while if it is too high, friction loss will increase. Therefore, maintaining the back pressure at an optimal value is important for improving the performance and reliability of the compressor.

To obtain this optimal back pressure value, in the scroll compressor of this embodiment, as shown in FIG. 1, the compression chamber oil supply passage 28 having a back pressure valve 27 for adjusting the back pressure of the back pressure chamber 18 is provided in the support portion 2c of the fixed scroll 2. When the back pressure valve 27 opens, the oil in the back pressure chamber 18 flows into the compression chamber 10 through the compression chamber oil supply passage 28.

27a is a back pressure valve piece (valve seat part) that serves as the valve seat of the back pressure valve 27, and is press-fitted into the fixed scroll 2. 29 is a back pressure valve accommodating space that accommodates the back pressure valve 27 and the spring 29b that presses the back pressure valve, and the spring 29b is supported by a stopper 29a. 29c shown in FIG. 6 is a stopper plug that seals and blocks the end of the side hole formed to provide the back pressure valve outflow path 28b.

The compression chamber oil supply passage 28 is composed of a back pressure valve inlet passage 28a that opens to the back pressure chamber 18, a back pressure valve outlet passage 28b that communicates with the compression chamber 10, and a back pressure valve housing space 29 that houses the back pressure valve 27. The back pressure valve inlet passage 28a is composed of a hole that penetrates the back pressure valve piece 27a.

Here, the configuration of the fixed scroll 2 in this embodiment will be described with reference to FIG.
In the fixed scroll 2 near the back pressure valve inlet passage 28a, an annular recess 24 located on the inner periphery side of the fixed end plate surface 2u and a bay-shaped recess 23 located on the outer periphery edge of the orbiting end plate 3a are formed. The annular recess 24 is formed as an annular, preferably circular, portion having an outer diameter larger than the sweep range of the orbiting end plate 3a of the orbiting scroll 3 when it orbits.

The bay-shaped recess 23 is located on the inner side of the annular recess 24 and is configured to have a concave shape, preferably a bay-shaped shape, embedded in the outermost part of the fixed wrap 2b. This bay-shaped recess 23 always extends to the outside of the rotating head plate 3a, so it is always in communication with the back pressure chamber 18 and oil in the back pressure chamber 18 is always retained. This allows the compression chamber oil supply passage 28 to supply oil from the back pressure chamber 18 to the compression chamber 10 side from the opening on the bay-shaped recess 23 side.

The back pressure valve 27 is arranged to separate the back pressure valve inlet passage 28a from the back pressure valve outlet passage 28b, and opens when the pressure (back pressure) in the back pressure chamber 18 reaches a predetermined value Pm or higher, and the back pressure is maintained lower than the discharge pressure Pd. As a result, the back pressure is at an intermediate pressure Pm, which is higher than the suction pressure Ps and lower than the discharge pressure Pd. When compression by the compression chamber 10 begins and the back pressure valve 27 opens, the oil in the back pressure chamber 18 flows into the compression chamber 10.

In other words, the back pressure valve 27 has the function of releasing the fluid in the back pressure chamber 18 to the compression chamber 10 when the pressure in the back pressure chamber 18 exceeds a certain value, thereby adjusting the back pressure in the back pressure chamber 18 to an appropriate value.

The oil that flows into the compression chamber 10 effectively lubricates the wrap sliding surfaces and the gaps at the ends of the wraps, and is also used to seal between the compression chambers, improving sealing performance and improving the efficiency of the scroll compressor.

The oil that flows into the compression chamber 10 is then discharged from the discharge port 2d into the discharge space 11. A portion of this discharged oil is discharged, for example, together with the refrigerant gas from the discharge pipe 13 into the refrigeration cycle, and the remainder is separated from the refrigerant gas in the sealed container 8 and stored in the oil storage section 8d at the bottom of the sealed container 8.

In this embodiment, the back pressure valve outlet passage 28b is connected to the compression chamber 10 after the suction process is completed and compression has begun. Also, as shown in FIG. 2, the opening of the back pressure valve outlet passage 28b is provided at the center of the tooth base of the fixed scroll 2, and is alternately connected to both the orbiting outer line chamber and the orbiting inner line chamber by the orbiting motion of the orbiting scroll. Therefore, oil can be supplied to both compression chambers, and the problem of insufficient oil supply in any of the compression chambers 10 can be avoided.

As described above, according to the first embodiment of the present invention, the oil flowing into the back pressure chamber 18 is supplied to the suction chamber 16 side by the oil supply pocket 3d shown in FIG. 5, and is provided with a second oil supply passage that is supplied to the compression chamber 10 via the compression chamber oil supply passage 28, so that the suction chamber 16 and the compression chamber 10 can be well lubricated and sealed. Therefore, the lubricity of the scroll compressor can be improved to improve the reliability of the scroll compressor, and the volumetric efficiency can be improved, so that the efficiency of the scroll compressor can also be improved.

In addition, in this embodiment, a second oil supply passage having the back pressure valve 27 is provided, so that a portion of the oil in the back pressure chamber 18 can be supplied directly to the compression chamber 10 via the back pressure valve 27 without passing through the suction chamber 16.
That is, of the oil supplied to the back pressure chamber 18, only the amount determined by the first oil supply passage is introduced into the suction chamber, and the remaining oil is introduced into the compression chamber 10 via the second oil supply passage.
Therefore, by adjusting the amount of oil supplied to each of the first oil supply passage and the second oil supply passage, it is possible to control the amount of oil supplied to the suction chamber 16 and the amount of oil supplied to the compression chamber 10 to appropriate amounts.

A second embodiment of the scroll compressor of the present invention will be described with reference to FIG. 7. FIG. 7 is a diagram for explaining this second embodiment, and corresponds to FIG. 5. In FIG. 7, parts with the same reference numerals as in FIG. 1 to FIG. 6 indicate similar parts, and explanations of similar parts will basically be omitted, with the focus on different parts being explained.

In this second embodiment, as in the first embodiment, an oil supply pocket 3d is provided in the orbiting scroll 3, and oil from the back pressure chamber 18 is intermittently supplied to this oil supply pocket 3d. This embodiment differs from the first embodiment in that it is provided with an oil supply path 2m that discharges the oil supplied to the oil supply pocket 3d to the suction port 2s above (upstream of) the check valve (wall member) 21.

According to this embodiment, by providing the oil supply path 2m, the oil supplied to the oil supply pocket 3d can be discharged to the suction port 2s below the suction pipe 12 via the oil supply path 2m. Therefore, the oil discharged from the oil supply path 2m to the suction port 2s flows along the inclined portion 2t of the fixed scroll 2 to the suction portion 17 together with the inflow gas sucked from the suction pipe 12, so that the oil can be sufficiently supplied to the tooth tip side of the orbiting wrap 3b (the tooth bottom side of the fixed wrap 2b).

In addition, in this embodiment 2, as in the first embodiment, the suction groove 2r and the tapered portion 2k are also provided, so that the oil in the oil supply pocket 3d is discharged upward from the tapered portion 2k. Therefore, as in the first embodiment, the oil discharged from the tapered portion 2k can also be supplied to the tooth tip side of the orbiting wrap 3b (the tooth bottom side of the fixed wrap 2b).

Therefore, according to this embodiment 2, the same effects as those of the first embodiment can be obtained, and the lubrication and sealing properties in the suction chamber 16 and the compression chamber 10 can be further improved, thereby further improving the efficiency of the scroll compressor.

In the second embodiment shown in FIG. 7, the oil supply path 2m, the suction groove 2r, and the tapered portion 2k are included. However, the same effect as in the first embodiment can be obtained by eliminating the tapered portion 2k downstream of the suction groove 2r and extending the suction groove 2r accordingly, or by eliminating the suction groove 2r and leaving only the oil supply path 2m.

According to this second modification, the oil supplied from the oil supply pocket 3d is discharged to the suction port 2s above (upstream of) the check valve 21, so that sufficient oil can be supplied to the tooth tip side of the orbiting wrap 3b (the tooth bottom side of the fixed wrap 2b), improving the lubrication and sealing properties in the suction chamber 16 and compression chamber 10.

A third embodiment of the present invention will be described with reference to Fig. 8. Fig. 8 is a system schematic diagram showing a heat pump water heater using the scroll compressor of the present invention.
The heat pump water heater is composed of a heat pump unit 40 that heats up hot water and a hot water storage tank unit 41 that stores the hot water.

The heat pump unit 40 includes a scroll compressor 1 with a variable capacity, a water-refrigerant heat exchanger (condenser) 42 that exchanges heat between the high-temperature, high-pressure refrigerant discharged from the scroll compressor 1 and water, which is the medium to be heated, an expansion means 43 such as an expansion valve or a capillary tube that expands the refrigerant flowing out of the water-refrigerant heat exchanger 42 to a low temperature and low pressure, and an air-side heat exchanger (evaporator) 45 that exchanges heat between the low-temperature, low-pressure refrigerant flowing out of the expansion means 43 and air blown by a blower fan 44 to evaporate the refrigerant. The refrigerant gas flowing out of the air-side heat exchanger 45 is sucked into the scroll compressor 1. These devices are connected in a ring shape to form a refrigeration cycle (heating cycle).

The scroll compressor 1 also includes a discharge refrigerant temperature detector 46 that detects the temperature on the discharge side of the scroll compressor 1, an outlet refrigerant temperature detector 47 that detects the temperature of the refrigerant flowing out of the air-side heat exchanger 45, and an outside air temperature detector 48 that detects the outside air temperature. Each of the temperature detectors 46 to 48 is connected to a control unit 49, which controls the capacity of the scroll compressor 1 and the expansion means 43 based on the temperatures detected by each of the temperature detectors 46 to 48. Note that carbon dioxide is used as the refrigerant in the refrigeration cycle of this heat pump water heater.

As shown in FIG. 8 , low-temperature water is supplied to the water-refrigerant heat exchanger 42 from the bottom of the hot water storage tank 50 via water piping 52 by driving a circulation pump 51, and after heat exchange in the water-refrigerant heat exchanger 42 and becoming high-temperature water, the water is returned to the top of the hot water storage tank 50.
Meanwhile, water is supplied from the outside to the bottom of the hot water storage tank 50, and high-temperature hot water is supplied from the top of the hot water storage tank 50 and sent to the kitchen, bath, and other uses.

The heat pump water heater of this embodiment 3 configured in this manner employs the scroll compressor 1 described in the above-mentioned embodiment 1 or embodiment 2 as the scroll compressor 1, and therefore has the effect of improving the efficiency of the heat pump water heater.

The present invention is not limited to the above-described embodiment, but includes various modified examples. For example, in the above embodiment, the scroll compressor 1 is a vertical scroll compressor, but the present invention can be applied to a horizontal scroll compressor in the same manner.
Furthermore, the above-described embodiment has been described in detail in order to easily explain the present invention, and the present invention is not necessarily limited to having all of the configurations described.

1...Scroll compressor, 1A...Compression mechanism part,
2... fixed scroll, 2a... fixed end plate, 2b... fixed wrap, 2c... support portion,
2d: discharge port; 2e: bypass hole; 2k: tapered portion; 2m: oil supply path;
2r...suction groove, 2s...suction port, 2t...inclined portion,
2u: fixed end plate surface (thrust support surface),
3...rotating scroll, 3a...rotating head plate,
3a1: upper surface of the rotating head (rotating thrust surface), 3a2: edge of the rotating head,
3a3...lower surface of the rotating head plate, 3b...rotating wrap, 3c...rotating boss portion,
3d...oil supply pocket (oil supply recess),
4...Frame, 5...Oldham Ring,
6... crankshaft, 6a... eccentric pin portion (pin portion), 6b... oil supply hole, 6c... oil supply pipe,
7...motor section, 7a...rotor, 7b...stator,
8: sealed container, 8a: body, 8b: lid cap, 8c: bottom cap, 8d: oil storage section,
9: motor chamber, 10: compression chamber, 11: discharge space (fixed rear chamber),
12...suction pipe, 13...discharge pipe, 14...main bearing, 15...slewing bearing,
16...suction chamber, 17...suction section, 18...back pressure chamber,
19...Space inside the swivel boss (swivel bearing chamber),
21: check valve (wall member), 22: bypass valve,
23... bay-shaped recess, 24... annular recess,
25... Auxiliary bearing, 25a... Bearing bush, 25b... Auxiliary bearing housing,
26... sub-frame, 27... back pressure valve, 27a... back pressure valve piece (valve seat part),
28... compression chamber oil supply passage, 28a... back pressure valve inlet passage, 28b... back pressure valve outlet passage,
29: Back pressure valve accommodating space; 29a: Stopper; 29b: Spring; 29c: Stopper plug;
30: power supply terminal; 31: sweep area during pivoting; 32: pivoting direction;
35, 36 ... counterweight, 37 ... stopper, 38 ... spring,
40... heat pump unit section, 41... hot water tank unit section,
42...water-refrigerant heat exchanger (condenser), 43...expansion means, 44...blower fan,
45: air-side heat exchanger (evaporator), 46: discharge refrigerant temperature detection unit,
47: Outlet refrigerant temperature detection unit, 48: Outside air temperature detection unit, 49: Control unit,
50...hot water tank, 51...circulation pump, 52...water piping.

Claims (12)

a crankshaft for causing the orbiting scroll to perform orbital motion; an orbiting bearing provided in an orbiting boss portion of the orbiting scroll for supporting the orbiting scroll axially and rotatably relative to an eccentric pin portion of the crankshaft; an orbiting boss inner space having a pressure close to a discharge pressure to which lubricating oil stored in a sealed container is introduced; a back pressure chamber provided on the back surface of the orbiting scroll and radially outward of the orbiting boss inner space, the back pressure chamber being a pressure between the discharge pressure and the suction pressure; and a suction port provided on the radially outward side of the fixed end plate of the fixed scroll to which a refrigerant gas from a suction pipe is introduced.
A suction portion provided on the fixed end plate between the suction port and the suction chamber;
a wall member provided on an opposite side of the suction pipe at the suction port, the wall member deflecting a flow of the refrigerant gas from the suction pipe into an oblique flow;
an oil supply recess provided on an outer circumferential side of the rotating head, into which oil from the back pressure chamber is guided;
a suction groove provided in the fixed end plate for guiding oil from the oil supply recess toward the suction portion;
a tapered portion formed on an outlet side of the suction groove for discharging at least a portion of the oil from the suction groove to a tooth tip side of the orbiting wrap,
a suction groove having an opening on the suction portion side that opens onto a rear surface side of the wall member, and the wall member is configured to act as an umbrella for oil flowing out of the suction groove against refrigerant gas flowing in from the suction pipe. The scroll compressor according to claim 1,
The fixed end plate forming the suction portion includes an inclined portion inclined from the suction port side toward the suction chamber side,
The scroll compressor, wherein the wall member deflects a flow of refrigerant gas from a suction pipe toward the inclined portion. The scroll compressor according to claim 2,
The scroll compressor, wherein the tapered portion is formed so that at least a portion of the oil discharged from the suction groove is discharged toward the inclined portion. The scroll compressor according to claim 1,
The scroll compressor according to claim 1, wherein the oil supply recess is an oil supply pocket formed on an outer circumferential side of an upper surface of a rotating head plate of the rotating scroll. The scroll compressor according to claim 1,
The scroll compressor according to claim 1, wherein the wall member is a check valve provided at the suction port . The scroll compressor according to claim 5,
a check valve configured to act as an umbrella of oil flowing out of the suction groove against refrigerant gas flowing in from the suction pipe, the check valve being configured so that an opening of the suction groove on the suction portion side opens to a rear side of the check valve, the check valve acting as an umbrella of oil flowing out of the suction groove against refrigerant gas flowing in from the suction pipe. The scroll compressor according to claim 6,
A scroll compressor characterized in that an opening end of the tapered portion in the suction groove is located on the back side of the check valve, and a portion having a length of 40 to 60% of the diameter of the check valve functions as an umbrella for oil discharged from the tapered portion. The scroll compressor according to claim 7,
a tapered portion of the suction groove having an opening end located on a rear surface side of the check valve near a center thereof; The scroll compressor according to claim 1,
the fixed scroll is provided with a compression chamber oil supply passage having a back pressure valve for adjusting the back pressure of the back pressure chamber, the compression chamber oil supply passage including a back pressure valve inlet passage opening into the back pressure chamber and a back pressure valve outlet passage communicating with the compression chamber. a crankshaft for causing the orbiting scroll to perform orbital motion; an orbiting bearing provided in an orbiting boss portion of the orbiting scroll for supporting the orbiting scroll axially and rotatably relative to an eccentric pin portion of the crankshaft; an orbiting boss inner space having a pressure close to a discharge pressure to which lubricating oil stored in a sealed container is introduced; a back pressure chamber provided on the back surface of the orbiting scroll and radially outward of the orbiting boss inner space, the back pressure chamber being a pressure between the discharge pressure and the suction pressure; and a suction port provided on the radially outward side of the fixed end plate of the fixed scroll to which a refrigerant gas from a suction pipe is introduced.
A suction portion provided on the fixed end plate between the suction port and the suction chamber;
a wall member provided on an opposite side of the suction pipe at the suction port, the wall member deflecting a flow of the refrigerant gas from the suction pipe into an oblique flow;
an oil supply recess provided on an outer circumferential side of the rotating head, into which oil from the back pressure chamber is guided;
a fixed end plate having an oil supply passage for discharging oil from the oil supply recess to the suction port on the upstream side of the wall member; The scroll compressor according to claim 10,
a suction groove provided in the fixed end plate for guiding oil from the oil supply recess toward the suction portion;
A tapered portion is formed on an outlet side of the suction groove for discharging at least a portion of the oil from the suction groove to a tooth tip side of the orbiting wrap,
a suction groove having an opening on the suction portion side that opens onto a rear surface side of the wall member, and the wall member is configured to act as an umbrella for oil flowing out of the suction groove against refrigerant gas flowing in from the suction pipe. A heat pump water heater comprising a heat pump unit section that heats up hot water and a hot water storage tank unit section that stores hot water, the heat pump unit section comprising a scroll compressor, a water-refrigerant heat exchanger that exchanges heat between a high-temperature, high-pressure refrigerant discharged from the scroll compressor and water as a medium to be heated, an expansion means that expands the refrigerant flowing out of the water-refrigerant heat exchanger to a low-temperature, low-pressure refrigerant, and an air-side heat exchanger that evaporates the low-temperature, low-pressure refrigerant flowing out of the expansion means, the scroll compressor being the scroll compressor described in any one of claims 1 to 11.

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