Daikin Industries Patente

The disclosure provides a method for producing a polytetrafluoroethylene molded article, capable of improving the tensile strength of the resulting polytetrafluoroethylene molded article, regardless of whether the polytetrafluoroethylene used is a recycled product or a virgin product, without using a special infrared irradiation device and a rubber mold, and a polytetrafluoroethylene molded article. Provided is a method for producing a polytetrafluoroethylene molded article, including a rolling step of rolling polytetrafluoroethylene at 50 MPa or higher to obtain a molded article.

An electric component module 10 includes a first board 21 having a first circuit 31 including a noise generation source, a second board 22 having a second circuit 32 including a microcomputer 35 that transmits and receives a communication signal CS to and from a control circuit 41 other than the first circuit 31, the second board 22 being separated from the first board 21, and an electric wire 51 that transmits and receives a simple signal SS between the first circuit 31 and the second circuit 32.

A first head (31) has a first discharge port (49). A first discharge valve (60) opens and closes the first discharge port (49). A first fastener (61) fixes a base end portion of the first discharge valve (60) to the first head (31). A cylinder (70) has a vane chamber (73) configured to house a vane (77), the vane chamber (73) having a first center line (L1). The first head (31) is divided into a first region on the side of the first center line (L1) corresponding to the suction space and a second region on the side of the first center line (L1) corresponding to the discharge space when viewed from a first direction. The first fastener (61) is disposed in the first region of the first head (31).

A hot water supply unit includes: a refrigerant unit (U) including a refrigerant circuit (R1) that performs a refrigeration cycle using a first refrigerant that is a flammable refrigerant; a tank (41) configured to store water directly or indirectly heated by the first refrigerant; and a casing (60) disposed in the indoor space (I) and configured to house the refrigerant unit (U) and the tank (41). The refrigerant unit (U) is disposed below the tank (41).

A refrigeration cycle apparatus (100) includes a heat source heat exchanger (13) and a bridge circuit (40). The heat source heat exchanger (13) includes a refrigerant inlet pipe (13a), a refrigerant outlet pipe (13b), a plurality of refrigerant paths (61), a diverger (50), and a converger (70). The bridge circuit (40) always causes a refrigerant (R) to flow into the heat source heat exchanger (13) at the refrigerant inlet pipe (13a) and flow out of the heat source heat exchanger (13) at the refrigerant outlet pipe (13b). The plurality of refrigerant paths (61) is connected to a plurality of diverger pipes (56) of the diverger (50) and a plurality of converger pipes (75) of the converger (70). The number of the diverger pipes (56) is smaller than the number of the converger pipes (75).

A heat source unit (2) includes an electric component unit (70), a heat source-side refrigerant main flow path (300), and a first refrigerant sub flow path (46) including a first cooling portion (47) that cools a first portion of the electric component unit (70) and a second portion of the electric component unit (70). The heat source-side refrigerant main flow path (300) includes an accumulator (29), a compressor (21), a heat source-side heat exchanger (23), and a heat source-side expansion valve (25). The heat source-side refrigerant main flow path (300) is connected to a utilization-side refrigerant flow path (500) of a utilization unit (3a, 3b) to form a refrigerant circuit (10). The first refrigerant sub flow path (46) branches from a liquid flow path (340) extending from the heat source-side heat exchanger (23) to the utilization-side refrigerant flow path (500) in the heat source-side refrigerant main flow path (300), and causes a refrigerant to flow in a gas flow path (310) between the accumulator (29) and the compressor (21) in the heat source-side refrigerant main flow path (300).

A rotary compressor includes a shaft extending in a first direction, a motor to drive the shaft, a first bearing including a discharge hole to discharge a compressed refrigerant, and supporting the shaft, a cylinder including a cylinder chamber formed inside the cylinder, a roller to eccentrically rotate in the cylinder chamber, and a muffler disposed so as to cover the discharge hole, wherein the motor, the muffler, the first bearing, and the cylinder are arranged in stated order along the first direction, the first bearing includes a boss which supports the shaft and protrudes toward the muffler, the muffler includes an opening through which the boss is disposed, and the first bearing or the muffler includes one or more positioning structures to determine a position of the muffler with respect to the first bearing such that clearance in the opening is formed along an entire periphery of the boss.

The rotary compressor (1) includes a drive shaft (31), a compression mechanism (30) for a refrigerant, and a casing (10). The compression mechanism (30) has a bearing (41) fixed to the casing (10) by a fixture member (44). The fixture member (44) has a first plate portion (44a) above the bearing (41), and the fixture member (44) and the compression mechanism (30) have a flow path for a fluid. The flow path includes a fluid inlet (44d) including a first plate portion (44a), a wall surface (41k) below the fluid inlet (44d), a first space (P1) between the fluid inlet (44d) and the wall surface (41k), a second space (P2) which is positioned below the fixture member (44) and shifted from the first space (P1) in a radial direction and/or a circumferential direction and through which the fluid that has collided with the wall surface (41k) flows, and a fluid outlet (41j) below the second space (P2).

With a charging method, a refrigeration apparatus 1 is filled with a refrigerant and an odor component. The charging method includes a first step of providing a cylinder 51 containing a mixed liquid in which the odor component is dissolved, a second step of connecting the cylinder 51 to a refrigerant circuit 10 of the refrigeration apparatus 1, and a third step of filling the refrigerant circuit 10 with the mixed liquid supplied from the cylinder 51. Since the refrigerant and the odor component are mixed in a liquid phase, the odor component can be stably supplied and charged into the refrigerant circuit 10 at an appropriate concentration.

A refrigerant flow path module (40) includes a flow path unit (32) provided with a first refrigerant flow path (R1) and a second refrigerant flow path (R2) through which a refrigerant flows, and a casing (33) that accommodates the flow path unit (32), in which the flow path unit (32) is formed with a synthetic resin or a material containing aluminum as a main component, and the casing (33) is formed with a steel material.

In a rotary compressor, when viewed in an axial direction, a region that overlaps a cylinder chamber (S1) between a blade (38) and a thin portion (52) is defined as a first region (77); a region that overlaps the cylinder chamber (S1) between the blade (38) and a suction port is defined as a second region (78); and when a piston (35) is located at a bottom dead center, a gap (CR1) between part of an outer edge of the piston (35) that corresponds to the first region (77) and part of a closing member (50) that corresponds to the first region (77) is larger than a gap (CR2) between part of the piston (35) that corresponds to the second region (78) and part of the closing member (50) that corresponds to the second region (78).

An indoor unit is an indoor unit of an air conditioning apparatus. The indoor unit is configured to adopt a zeotropic refrigerant as a refrigerant. The indoor unit includes a main heat exchanger, a flow divider, and a sensor. The main heat exchanger includes a plurality of tube passes through which the refrigerant flows. The flow divider is configured to divide the refrigerant before the refrigerant flows into the plurality of tube passes. The sensor is configured to detect a temperature of the refrigerant. The sensor is disposed near the flow divider, is disposed between the flow divider and the main heat exchanger, or is disposed on one of the tube passes defined by heat transfer tubes of the main heat exchanger, at a position that is closer to the flow divider than a midpoint of an entire length of the one of the tube passes is.

A first switching mechanism (15) is switchable between a first state in which a discharge side of a first compressor (11) is connected to a first water heat exchanger (14) or a refrigerant heat exchanger (30) and a second state in which the discharge side of the first compressor (11) is connected to a heat source heat exchanger (12). In a defrosting operation for defrosting the heat source heat exchanger (12), a control unit (100) drives the first refrigerant circuit (10) with the first switching mechanism (15) set in the second state.

The displacement volume of a compression mechanism (40) is defined as Vc [cc], the density of a refrigerant at 1.9 Mpa and 75°C as Dg [g/cm<3>], the number of revolutions of a rotary shaft (30) as N [rps], the volume of a primary space (S1) as V1 [cc], the volume of a secondary space (S2) as V2 [cc], the height of the primary space (S1) as H1 [cm], the height of the secondary space (S2) as H2 [cm], the density of refrigerating machine oil at 15°C as Do [g/cm<3>], and the solution viscosity of the refrigerating machine oil present at a level of a suction port (71a) or lower as η [mPa·S]. The rotary compressor satisfies relational expressions: N ≥ 100 [rps]; and ((8.19 × 10<-8> × Vc × Dg + 0.000327) × Vc<3.657> × N<3.126>)/(V1 × V2 × H1<1.867> × H2<1.556> × Do × η) ≤ 1.0. <img class="EMIRef" id="9bc56977-2269-4b63-9ad7-c8054ca75a0e-ia01" />

When a first compressor (11) and a second compressor (51) are in a stopped state, a control unit (100) executes a first operation in which the first compressor (11) is operated while keeping the second compressor (51) in the stopped state to cause heat dissipation of a first refrigerant in a refrigerant heat exchanger (52). After the first operation, the control unit (100) executes a second operation in which the second compressor (51) is operated.

An injection flow path (61) communicating with an injection pipe (9c) is formed in a first cylinder (31, 41), a middle plate (55), and a second cylinder (31, 41). The injection flow path (61) includes: a first flow path (61a) connected to the injection pipe (9c); a second flow path (61b, 61c) branching from the first flow path (61a) and communicating with a first cylinder chamber (S1, S2); and a third flow path (61b, 61c) branching from the first flow path (61a) and communicating with the second cylinder chamber (S1, S2).

A rotary compressor includes: a casing (16) that forms a first space (Si) in which a refrigerant at a suction pressure flows; an electric motor (10) disposed in the first space (Si); a drive shaft (70) that is rotated about its axis; and a compression mechanism (15) that compresses the refrigerant in the first space (Si) and discharges the compressed refrigerant from a discharge port (24, 29). The casing (16) forms the oil reservoir (85) that stores the refrigerating machine oil and the high-pressure gas space (HS) into which the refrigerant discharged from the discharge port (24, 29) flows and which communicates with the vane chambers (48, 49). The oil separation mechanism (82) that separates the refrigerant and the refrigerating machine oil discharged from the discharge port (24, 29) from each other is disposed in the high-pressure gas space (HS).

A refrigeration apparatus includes a refrigerant unit (U) that includes a first refrigerant circuit (R1) configured to perform a refrigeration cycle by using a first refrigerant, which is a highly flammable refrigerant, in which the first refrigerat circuit (R1) includes a first refrigerant pipe (27a) that is configured to connect a first heat exchanger (23) and a decompression mechanism (24) to each other, a second refrigerant pipe (27b) that is configured to connect the decompression mechanism (24) and a second heat exchanger (22) to each other, a third refrigerant pipe (27c) that is configured to connect the second heat exchanger (22) and a compressor (21) to each other, and a fourth refrigerant pipe (27d) that is configured to connect the compressor (21) and the first heat exchanger (23) to each other, and in which the first to fourth refrigerant pipes (27a to 27d) have structures in which a first capacity, which is a sum of a capacity of the first refrigerant pipe (27a) and a capacity of the second refrigerant pipe (27b), is smaller than a second capacity, which is a sum of a capacity of the third refrigerant pipe (27c) and a capacity of the fourth refrigerant pipe (27d).

The indoor unit is a wall-mounted indoor unit of an air conditioner. The indoor unit includes a heat exchanger, a refrigerant detection sensor, a partitioning member, and an auxiliary pipe. The heat exchanger is disposed in a first space. The refrigerant detection sensor is disposed in a second space. The partitioning member partitions the first space and the second space. The auxiliary pipe is disposed to extend from the first space to the second space across the partitioning member. One end of the auxiliary pipe is connected to the heat exchanger in the first space, and the other end of the auxiliary pipe is located in the second space.

A lower end surface of a roller (36) of a rotary compressor (1) has a horizontal surface (36a) parallel to an upper surface of a rear head (42), and an inclined surface (36b) continuous with an outer peripheral side of the horizontal surface (36a); extending to an outer peripheral surface (36o) of the roller (36); and inclined so as to be positioned higher at a radially outer side.

In a rotary compressor, a cylinder (31, 41, 231, 241, 331) and a closing member (50, 55, 56, 250, 255, 256, 350, 356) are fixed to each other by a plurality of bolts (B) extending in an axial direction of a rotary shaft (90). The plurality of bolts (B) include: a first bolt (B1) between a suction pipe (14, 214a, 214b, 314) and a housing (33, 43) housing a blade (38, 48) as viewed in the axial direction; and a second bolt (B2) between the housing (33, 43) and an imaginary line (IL), which is symmetrical to a center line (AL) of the suction pipe (14, 214a, 214b, 314) with respect to the housing (33, 43), as viewed in the axial direction.

A refrigeration cycle apparatus (100) includes a heat source heat exchanger (13), a utilization heat exchanger (23), and a bridge circuit (40). The heat source heat exchanger (13) includes a refrigerant inlet pipe 13a and a refrigerant outlet pipe 13b. The bridge circuit (40) always causes the refrigerant to flow into a first heat exchanger at the refrigerant inlet pipe and flow out of the first heat exchanger at the refrigerant outlet pipe. The first heat exchanger includes a diverger (50). A diverger body (51) of the diverger (50) has one intake port (53) and a plurality of exhaust ports (54). A plurality of refrigerant paths (61) of the heat source heat exchanger (13) includes a lowest path (61L) disposed at a height (H1) that is lowest. A height (H0) of the plurality of exhaust ports (54) is all higher than the height (H1) of the lowest path.

A refrigerant compressor (10) uses carbon dioxide as a refrigerant. A casing (13) houses a crankshaft (25), a motor (21), and a compression mechanism (30). The crankshaft (25) is provided with, at a lower end portion thereof, an oil supply mechanism (38) having a suction port (39) through which oil stored in a lower end portion of the casing (13) is drawn. A displacement volume Vcc [cc] per rotation of the compression mechanism (30) and a distance L1 [mm] between the suction port (39) and a lower end of a member joined to the casing (13), among members constituting the compression mechanism (30), satisfy the following condition: L 1 / Vcc > 13 . <img class="EMIRef" id="5739c957-1320-495d-92b5-3d7afefa9609-ia01" />

A first cylinder (31) is provided with a first valve housing portion (31j) recessed from the inner peripheral surface toward the outer side and housing a first reed valve (63) and a valve retainer (64). The valve retainer (64) has a first surface (64b) facing the first reed valve (63) and a second surface (64c) opposite to the first surface (64b). A center line (C1) extending in the longitudinal direction of the first reed valve (63) crosses an opening of the first valve housing portion (31j) that is close to the first cylinder chamber (S1). A first edge (31k) that is located on the opening of the first valve housing portion (31j) which is close to the first cylinder chamber (S1) and that is close to the valve attachment surface (31g) is located closer to the second surface (64c) of the valve retainer (64) than the valve attachment surface (31g) in a first direction orthogonal to the valve attachment surface (31g).

A refrigerant is a single component refrigerant composed of a hydrocarbon refrigerant, or a refrigerant mixture containing the hydrocarbon refrigerant. Refrigerating machine oil present at a level of a suction port (71a) or lower in an oil reservoir (35) has a solution viscosity η of 5.0 [mPa·s] or more.

The first surface (51) includes a valve seat surface (58) that is in contact with the tip portion (72) of the reed valve (70) in a closed state and a groove (59) that is formed around the valve seat surface (58) and overlaps an outer edge (72a) of the tip portion (72) as viewed in a second direction. The first surface (51) has a contact surface (75) that is configured to be in contact with the movable portion (73) of the reed valve (70) in the closed state.

The fastening member (80) includes a head (80a) and a shaft (80b) extending from the head (80a) in a second direction. The base portion (71) of the reed valve (70) has a first hole (83) through which the shaft (80b) of the fastening member (80) is inserted. The valve retainer (60) has a second hole (84) through which the shaft (80b) is inserted. The partitioning member (90) has a first space (81a) that is located outside the valve chamber (50) and houses the head (80a).

The reed valve (70) includes a base portion (71) fixed to the valve retainer (60), a tip portion (72) configured to open and close the outflow port (44), and a constricted portion (73) connecting the base portion (71) and the tip portion (72). The constricted portion (73) has a narrower width in a third direction orthogonal to the first direction and the second direction than the base portion (71). An inner side surface (53, 54) forming the valve chamber (50) is formed outside the constricted portion (73) in the third direction as viewed in the second direction. The valve retainer (60) has a side surface (61, 62) formed outside the constricted portion (73) in the third direction as viewed in the second direction.

An injection mechanism (40) includes a valve chamber (50), a first flow path (42, 43) that allows an injection pipe (39) and the valve chamber (50) to communicate with each other and has an outflow port (44) facing the valve chamber (50), and a second flow path (45) that is located at one end of the valve chamber (50) in a first direction and allows the valve chamber (50) and a compression chamber (15b, 25b) to communicate with each other. An inner surface forming the valve chamber (50) includes a first surface (51) forming the outflow port (44), and an inner surface forming the first flow path (42, 43) includes a first inclined surface (47) that is continuous with the first surface (51) and is inclined toward one end in the first direction to approach the second flow path (45) as the first inclined surface (47) extends toward the first surface (51).

A refrigeration apparatus (1) includes a refrigerant circuit (10), wherein tetrahydrothiophene, as an odor component, is sealed in the refrigerant circuit (10) along with a refrigerant and a refrigerating machine oil, and following Formula (1) is satisfied, where an amount of leakage of the refrigerant that leaks from the refrigerant circuit (10) at a leakage rate of 0.001 kg/h for four minutes is referred to as M<leak1> [kg], a fill amount of the odor component into the refrigerant circuit (10) is referred to as M<od> [kg], a fill amount of the refrigerating machine oil is referred to as M<oil> [kg], solubility of the odor component in the refrigerating machine oil is referred to as S<oil> [weight ppm], a fill amount of the refrigerant into the refrigerant circuit (10) is referred to as M<ref> [kg], a volume of a room (LS) is referred to as V [m<3>], and a density of the odor component is referred to as ρ [kg/m<3>]. [Formula 1] 1 > M leak 1 × M od − M oil × S oil / M ref 0.25 × V × ρ <img class="EMIRef" id="47e9cd3b-fd97-46d5-a8ba-803150d14fef-ia01" />

A technique by which the performance of a closed impeller of a centrifugal compressor can be improved is provided. A compressor 10 according to an embodiment of the present disclosure includes an impeller 200, and a casing 100 configured to house the impeller 200. The impeller 200 includes a hub 210 having a meridional plane 211, a plurality of blades 220 provided on the meridional plane 211, and a shroud 230 provided on tips of the plurality of blades 220 so as to cover the meridional plane 211. The shroud 230 has a first passage 235 penetrating between an inner surface of the shroud 230 facing the meridional plane 211 and an outer surface of the shroud 230 facing an inner surface of the casing 100. The first passage 235 has a first opening 235B in the outer surface of the shroud 230 and a second opening 235A in the inner surface of the shroud 230. In a cross section including an axis AX of a rotating shaft 250 of the impeller 200, the first passage 235 is inclined such that a center 235Bc of the first opening 235B is located on an inlet 200in side of the impeller 200 relative to a center 235Ac of the second opening 235A.

A rotary compressor including: a casing; a cylinder disposed inside the casing; a piston configured to eccentrically rotate inside the cylinder; a hollow shaft coupled to the piston and having an internal space; an upper bearing disposed over the cylinder and configured to rotatably support the shaft; a lower bearing disposed under the cylinder and configured to rotatably support the shaft; a rear muffler disposed under the lower bearing; and a positive displacement pump attached to the rear muffler and configured to discharge oil into the internal space.

A refrigeration cycle apparatus with which highly efficient operation is possible has been demanded. An air conditioner (100) includes a first refrigerant circuit (110) and a second refrigerant circuit (120). The first refrigerant circuit includes a first compressor (10), a first heat exchanger (40) functioning as a radiator for a refrigerant, a first expansion valve (50), and a second heat exchanger (60) functioning as a heat absorber for the refrigerant. The second refrigerant circuit connects a portion between the first compressor and the first heat exchanger and a portion between the first heat exchanger and the first expansion valve. The second refrigerant circuit includes a second compressor (20). Suction pressure of the first compressor is lower than suction pressure of the second compressor. The first compressor is a scroll compressor, and the second compressor is a rotary compressor. Alternatively, the first compressor is a scroll compressor having a first design compression ratio, and the second compressor is a scroll compressor having a second design compression ratio smaller than the first design compression ratio.

To provide a refrigeration cycle apparatus capable of performing efficient operation even under a low-load condition. An air conditioner (100) includes a first refrigerant circuit (110), a second refrigerant circuit (120), a bypass flow path (130), and a bypass valve (132). The first refrigerant circuit includes a first compressor (10), a radiator (40), a first expansion valve (50), and a heat absorber (60). The second refrigerant circuit connects a portion between the first compressor and the radiator and a portion between the radiator and the first expansion valve to each other and includes an economizer (70), a first valve (80), and a second compressor (20). The economizer is disposed between the radiator and the heat absorber, and the second compressor sucks a refrigerant that has passed through the economizer. The bypass flow path connects a portion between the first valve and the second compressor and a portion between the heat absorber and the first compressor. The bypass valve is disposed in the bypass flow path. The second compressor is a compressor that is smaller in displacement than the first compressor.

A rotary compressor includes: a casing (11); a cylinder (41, 42) disposed inside the casing; a piston (61, 62) configured to eccentrically rotate inside the cylinder; a shaft (81) coupled to the piston (61, 62) and having a cavity (81a) therein; piping (85, 185, 285, 385) disposed inside the cavity (81a) and spaced apart from a wall of the cavity (81a); an upper bearing (32) disposed over the cylinder and configured to rotatably support the shaft; a lower bearing (31) disposed under the cylinder and configured to rotatably support the shaft; a rear muffler (34) disposed under the lower bearing; and a positive displacement pump (50) attached to the rear muffler and configured to discharge oil between the piping and the wall.

An outdoor unit (3) of an air conditioner (1) is provided with a blow-out grille (59) including a connecting rib (70) extending radially and a plurality of concentric annular ribs (80) intersecting the connecting rib (70). The annular ribs (80) include a first annular rib (81) and a second annular rib (82). In a direction orthogonal to an rotation axis (X1) of the fan (38), the first annular rib (81) is disposed in a first region (61), and the second annular rib (82) is disposed in a second region (62) located further toward the outer peripheral side of the blow-out grille (59) than the first region (61). In a cross-section including the rotation axis (X1), the first annular rib (81) is inclined in a direction further toward the rotation axis (X1) with increasing distance from the fan (38), and the second annular rib (82) is inclined in a direction further toward an outer periphery of the blow-out grille (38) than the first annular rib (81), with increasing distance from the fan (38).

A screw compressor includes a compression mechanism including a screw rotor and configured to compress a refrigerant; a rotation shaft to which the screw rotor is fixed; a motor configured to rotate the rotation shaft; and a casing having a suction chamber configured to introduce the refrigerant from outside, a rotor chamber configured to house the compression mechanism, and a motor chamber configured to house the motor and positioned between the suction chamber and the rotor chamber, wherein the rotation shaft includes a first flow path that communicates with the suction chamber and that extends along a first direction that is an axial direction; and a second flow path that communicates with the motor chamber and the first flow path and that extends along a second direction intersecting the first direction.

Providing a refrigeration cycle apparatus capable of suppressing liquid compression. An air conditioner includes a first refrigerant circuit, a second refrigerant circuit, and a control device. The first refrigerant circuit includes a first compressor, a first heat exchanger functioning as a radiator during cooling operation, a first expansion valve, and a second heat exchanger functioning as a heat absorber during the cooling operation. The second refrigerant circuit c a portion between the first compressor and the first heat exchanger and a portion between the first heat exchanger and the first expansion valve. The second refrigerant circuit includes a second compressor and a first valve. The first valve is disposed on an upstream side of the second compressor. The control device controls the first compressor, the second compressor, the first expansion valve, and the first valve. The control device closes the first valve when the second compressor is to be stopped.

A rotary compressor includes: a casing; cylinders disposed inside the casing; pistons configured to eccentrically rotate inside the cylinders; a shaft connected to the pistons and including a cavity; a pipe disposed inside the cavity and apart from a wall of the cavity; an upper bearing disposed over the cylinders and configured to pivotally support the shaft; a lower bearing disposed below the cylinders and configured to pivotally support the shaft; a rear muffler disposed below the lower bearing; and a positive displacement pump attached to the rear muffler and configured to discharge oil into the pipe.

A heat source apparatus includes: a compressor (12) in a refrigerant circuit (11) that performs a refrigeration cycle; a cylinder (71) which is configured to store a flammable refrigerant for filling the refrigerant circuit (11) and which has a lower portion provided with a discharge port (711) through which the flammable refrigerant is discharged; an accumulator (17) connected to the compressor (12); and a casing (21) having a bottom plate (23) on which the compressor (12), the cylinder (17), and the accumulator (17) are installed, wherein in top view, a first virtual line (L1) connecting a center (12b) of the compressor (12) and a center (71b) of the cylinder (71) and a second virtual line (L2) connecting the center (12b) of the compressor (12) and a center (17b) of the accumulator (17) form a predetermined angle (θ).