JP4722727B2 - Compressor - Google Patents

Description

  The present invention relates to a compressor in which a driving force from an external drive source is directly transmitted to a main shaft and converts the rotational motion of the main shaft into a compression motion, and more particularly to a compressor suitable for a compressor of a vehicle air conditioner.

  In a clutchless compressor that transmits a driving force from an external drive source to a rotary shaft via a pulley, the external drive source may be damaged if the compressor is locked for some reason.

  For this reason, for example, the proposal which provided the torque limiter in the connection part of a main axis | shaft and a pulley is made | formed (for example, patent document 1). However, when a torque limiter is provided at the connecting portion between the main shaft and the pulley, the degree of freedom in designing the pulley is lowered and the cost of the apparatus may be increased. For this reason, a part of the main shaft is reduced in diameter and a breakage part with a lower strength than the other parts is provided, and when the compressor is locked, the main shaft is broken from the breakage part to break the external drive source. There has also been a proposal to prevent this (Patent Document 2).

However, the strength of the broken portion needs to be set in a range that can reliably protect the external drive source, and is usually set to be equal to or less than the slip torque of the belt connected to the pulley. However, even in this case, there is a possibility that the possibility that the fractured portion will fatigue due to fatigue due to repeated load applied to the main shaft during normal operation of the compressor cannot be wiped out.
JP-A-8-121336 Japanese Patent Laid-Open No. 10-9122

  The object of the present invention is to provide durability and reliability that can reliably prevent damage to an external drive source such as when the compressor is locked, while preventing fatigue failure of the break induction portion provided on the main shaft during normal operation of the compressor. It is to provide an excellent compressor.

  In order to solve the above problems, a compressor according to the present invention is a compressor driven by an external drive source, and a pulley connected to the external drive source side and a main shaft of the compressor are connected by a power transmission mechanism. In the compressor provided with a rotary motion conversion mechanism for converting the rotary motion of the main shaft into a compressive motion, the strength of a part of the main shaft is made stronger than the strength of the other portion on the pulley side than the rotary motion conversion mechanism of the main shaft. A circle having a lower torsional rigidity than the breakage inducing portion, provided with a lowered breakage inducing portion, covering the breakage inducing portion in the axial direction of the main shaft and being press-fitted into the main shaft at the front and rear portions. An annular member is provided.

  In the present invention, the fracture inducing portion is a portion in which the strength of a part of the main shaft is lower than the strength of the other portions, and preferentially when an excessive rotational torque is applied to the main shaft when the compressor is locked. The part to be broken. The fracture inducing portion can be constituted by, for example, a small diameter portion in which a part of the main shaft is made smaller in diameter than other portions.

  In the compressor as described above, since the annular induction member that covers the fracture inducing portion and the axial direction of the fracture inducing portion and is press-fitted into the main shaft at the front and rear portions is provided, the compressor is normally operated The main shaft and the annular member rotate at the same time without relative rotation. For this reason, since the rotational torque acts on both the main shaft and the annular member, the concentration of torque on the fracture inducing portion is suppressed. In addition, since the relative rotation of the two is prevented, a problem that the main shaft is twisted by the annular member is prevented, so that the main shaft is reliably prevented from being broken during the normal operation of the compressor. On the other hand, when a compressor lock or the like occurs and an excessive rotational torque acts on the main shaft, torque that causes the main shaft and the annular member to slip in the rotational direction is generated. When rotational slip occurs, the coefficient of friction between the main shaft and the annular member is greatly reduced, and the main shaft and the annular member rotate relative to each other. For this reason, the annular member does not receive the torsional force to be transmitted, and most of the torsional force acts on the main shaft, so that the main shaft is broken from the breakage inducing portion. Further, although the frictional force between the main shaft and the annular member remains even after the main shaft is broken, the relative rotational speed between the main shaft and the annular member is increased and the friction coefficient is decreased, which is sufficient for protecting the external drive source. Further, with time, the frictional force between the main shaft and the annular member disappears due to the wear of the main shaft or the annular member.

  About the press-fitting portion before and after the fracture inducing portion of the annular member, it is preferable that the press-fitting allowance of the pulley-side press-fitting portion is set smaller than the press-fitting allowance of the anti-pulley side press-fitting portion. For example, the press-fitting allowance of one press-fitted portion (pulley-side press-fitted portion) of the annular member slips with a torque smaller than the rupture torque of the rupture inducing portion, and does not slip under a load in a normal operation state of the compressor. Preferably, the press-fitting allowance of the other press-fitting portion (the anti-pulley side press-fitting portion) of the annular member is set to a press-fitting allowance that does not slip under a load in a normal operation state of the compressor.

  It is preferable that a layer made of a material that is more easily worn than the material forming the main shaft is interposed between at least one press-fitted portion of the annular member and the main shaft. By providing such a layer made of a material that easily wears, the main shaft and the annular member are likely to rotate relative to each other when the compressor is locked, so that it is possible to reliably realize protection of the external drive source by breaking the main shaft.

  In order to solve the above-mentioned problem, another compressor according to the present invention is a compressor driven by an external drive source, and a pulley connected to the external drive source side and a main shaft of the compressor are powered. In a compressor that is connected by a transmission mechanism and includes a rotary motion conversion mechanism that converts rotational motion of the main shaft into compression motion, the main shaft is connected to the first main shaft that is connected to each other on the pulley side of the rotary motion conversion mechanism. The second main shaft is provided with a large hole extending in the axial direction of the main shaft and a small hole extending further in the axial direction of the main shaft from the bottom of the large hole at the end of the first main shaft. A large hole press-fitted part press-fitted into the large hole part and a small hole press-fitted part press-fitted into the small hole part are provided at the end of the main shaft, and a breakage inducing part is provided between the large hole press-fitted part and the small hole press-fitted part. It consists of what is provided. Even in such a configuration, since the breakage inducing portion is provided between the large hole press-fitting portion and the small hole press-fitting portion, it is possible to reliably prevent the external drive source from being damaged when the compressor is locked.

  The press-fitting allowance between the small hole part and the small hole press-fitting part is preferably set to a press-fitting allowance that provides a friction torque larger than the breaking torque of the breakage inducing part. According to such a configuration, it is possible to reliably eliminate the possibility of the main shaft breaking during normal operation of the compressor.

  It is preferable that a relative rotation prevention pin for preventing relative rotation of both shafts is provided between the first main shaft and the second main shaft. If such a relative rotation prevention pin is provided, the relative rotation between the main shaft and the annular member during normal operation of the compressor is surely prevented, so that the main shaft may be broken during normal operation of the compressor. Is resolved more reliably.

  The press-fitting allowance between the large hole part and the large hole press-fitting part is preferably set to a press-fitting allowance that slips with a torque smaller than the rupture torque of the rupture inducing part and does not slip under a load in a normal operation state of the compressor. According to such a configuration, the main shaft can be reliably broken when the compressor is locked while preventing the main shaft from being broken during normal operation of the compressor.

  It is preferable that a layer made of a material that is more easily worn than the material forming the main shaft is interposed between the large hole portion and the large hole press-fitting portion. The layer made of the material that easily wears is not particularly limited, but can be formed from, for example, a resin layer.

  The present invention can be widely applied to a clutchless compressor that directly transmits a driving force from an external driving source to a rotating shaft via a pulley, and the type of the compressor is not particularly limited. For example, the present invention can be applied to a compressor that converts the rotational motion of the main shaft into a reciprocating motion of a piston, a compressor that has a movable scroll and a fixed scroll, and that converts the rotational motion of the main shaft into a turning motion of the movable scroll.

  According to such a compressor according to the present invention, it is possible to reliably prevent damage to the external drive source such as when the compressor is locked while preventing breakage due to fatigue failure of the main shaft during normal operation of the compressor. A compressor excellent in reliability and reliability can be obtained.

Hereinafter, preferred embodiments of the compressor of the present invention will be described with reference to the drawings.
1 and 2 show a compressor according to a first embodiment of the present invention, and in particular, shows a case where the present invention is applied to a swash plate compressor of a vehicle air conditioner. In FIG. 1, reference numeral 1 denotes a swash plate compressor. The swash plate compressor 1 has a housing 2. The housing 2 includes a front housing 3, a cylinder block 4, and a rear housing 5. The cylinder block 4 is provided with a plurality of cylinder bores 4a in the circumferential direction.

  A crank chamber 6 is formed between the front housing 3 and the cylinder block 4. A main shaft 7 is provided in the crank chamber 6 so as to extend through the crank chamber 6. One end of the main shaft 7 is supported in the center hole 8 of the cylinder block 4 via a needle bearing 9. The other end of the main shaft 7 is inserted through a cylindrical portion 3 a formed in the front housing 3.

  A rotor 10 is provided on the main shaft 7. A swash plate 11 is attached to the rotor 10 so that the inclination angle can be varied. A rocking plate 13 is provided on the swash plate 11 via a needle bearing 12 so as to be relatively rotatable.

  The swing plate 13 is prevented from rotating by the rotation prevention mechanism 14. The swing plate 13 is connected via a piston rod 15 to a piston 16 that is inserted in the cylinder bore 4a so as to be reciprocally movable. A valve plate device 17 is provided between the cylinder block 4 and the rear housing 5. The cylinder bore 4 a communicates with a suction chamber 19 formed in the rear housing 5 through a suction hole 18 provided in the valve plate device 17. The cylinder bore 4 a is communicated with a discharge chamber 21 formed in the rear housing 5 via a discharge hole 20 provided in the valve plate device 17.

  A pulley 22 is connected to the other end of the main shaft 7. The pulley 22 is rotatably mounted on the cylindrical portion 3 a of the front housing via a ball bearing 23. The pulley 22 is directly fixed to a screw part 24 formed at the other end of the main shaft 7. Note that a nut 25 is screwed to the screw portion 24.

  A belt 26 is connected to the pulley 22, and power from an external drive source (not shown) is transmitted through the belt 26. Examples of the external drive source include an engine and a motor as a vehicle prime mover.

  In the swash plate compressor 1 of FIG. 1, when power from an external drive source is transmitted to the main shaft 7 by a power transmission mechanism 27 including a pulley 22, a ball bearing 23, a belt 26, and the like, the main shaft 7 is rotated. Then, the rotational motion of the main shaft 7 is converted into the reciprocating motion of the piston 16 by the rotational motion conversion mechanism 28 including the rotor 10, the swash plate 11, the swing plate 13, and the like, and the refrigerant compressed in the cylinder bore 4a is discharged into the discharge chamber 21. It is designed to be discharged inside.

  A fracture inducing portion 29 is provided on the main shaft 7 on the pulley side of the rotational motion conversion mechanism 28. The fracture inducing portion 29 is composed of a small diameter portion in which a part of the main shaft 7 is formed with a small diameter, and the strength of the small diameter portion is lower than the strength of other portions. The main shaft 7 is provided with an annular member 30 that covers the fracture inducing portion 29 in the axial direction of the main shaft 7 and is press-fitted into the main shaft 7 at the front and rear portions, and has higher torsional rigidity than the fracture inducing portion. Yes.

  The press-fitting allowance of the pulley-side press-fitting portion 30a of the annular member 30 is set so as to slip with a torque smaller than the breaking torque of the breakage inducing portion 29 and not slip under the load of the compressor 1 in the normal operation state. . On the other hand, the press-fitting allowance of the non-pulley side press-fitting portion 30 b of the annular member 30 is set so as not to slip under the load of the compressor 1 in the normal operation state.

In the present embodiment, when the compressor 1 is operated, a load is applied to the main shaft 7, but since the front and rear in the axial direction of the breakage inducing portion 29 and the breakage inducing portion 29 are covered with the annular member 30, When the compressor is normally operated, the main shaft 7 and the annular member 30 rotate simultaneously without relative rotation. For this reason, since the rotational torque acts on both the main shaft 7 and the annular member 30, concentration of stress on the fracture inducing portion 29 is prevented. Further, since the relative rotation between the two is prevented, the annular member 30 prevents the main shaft 7 from being twisted, so that the main shaft 7 is reliably prevented from being broken during normal operation of the compressor. On the other hand, when a compressor lock or the like occurs and an excessive rotational torque acts on the main shaft 7, torque that causes the main shaft 7 and the annular member 30 to slip in the rotational direction is generated. When rotational slip occurs, the coefficient of friction between the main shaft 7 and the annular member 30 is greatly reduced, and relative rotation between the main shaft 7 and the annular member 30 is allowed. For this reason, the main shaft 7 is responsible for most of the torsional force transmitted, and the main shaft 7 is broken from the breakage inducing portion 29. However, although the annular member 30 remains without being broken even after the main shaft 7 is broken, since the relative rotation between the main shaft 7 and the annular member 30 is increased in this state, the friction coefficient is significantly reduced. The protection of the external drive source is fully achieved.

  Further, both press-fitting portions 30a and 30b of the annular member 30 are set so as not to slip under a load in a normal operation state of the compressor, and the relative rotation between the main shaft 7 and the annular member 30 is suppressed. Even if a load in the operating state is repeatedly applied to the main shaft 7, a problem that the main shaft 7 is broken is reliably prevented. In addition, since the press-fitting allowance of the pulley-side press-fitting portion 30a of the annular member 30 is set to slip with a torque smaller than the breaking torque of the breakage inducing portion 29, it exceeds the load in the normal operation state of the compressor, When a torque smaller than the rupture torque of the rupture inducing portion 29 acts, the main shaft 7 and the annular member 30 are relatively rotated, and the main shaft 7 is ruptured from the rupture inducing portion 29 to protect the external drive source.

  FIG. 2 shows a main shaft of a compressor according to the second embodiment of the present invention. In this embodiment, since the same configuration as that of the first embodiment is adopted, the same members are denoted by the same reference numerals, and the description thereof is omitted. In the present embodiment, the resin layer 31 is interposed between the pulley-side press-fit portion 30a and the main shaft 7 and between the anti-pulley-side press-fit portion 30b and the main shaft as a layer that is more easily worn than the material forming the main shaft 7. It is disguised.

  Also in this embodiment, according to the operation of the first embodiment, it is possible to reliably prevent breakage due to fatigue failure of the main shaft 7 during normal operation of the compressor while reliably preventing damage to the external drive source. Further, since the resin layer 31 is interposed between the pulley-side press-fitted portion 30a and the main shaft 7 and between the anti-pulley-side press-fitted portion 30b and the main shaft, the main shaft 7 and the annular shape are locked when the compressor is locked. The relative rotation of the member 30 is likely to occur. Therefore, the main shaft can be reliably broken and the external drive source can be protected.

  FIG. 3 shows a main shaft of a compressor according to the third embodiment of the present invention. The main shaft 32 in this embodiment is composed of a first main shaft 33 and a second main shaft 34 that are connected to each other on the pulley side of the rotational motion conversion mechanism. A large hole 35 extending in the axial direction and a small hole 36 extending in the axial direction from the bottom of the large hole 35 are provided at the end of the first main shaft 33. At the end of the second main shaft 34, there are provided a large hole press-fitting part 37 that is press-fitted into the large hole part 35 and a small hole press-fitting part 38 that can be press-fitted into the small hole part 36. A fracture inducing portion 39 is provided between the large hole press-fitting portion 37 and the small hole press-fitting portion 38 of the second main shaft 34.

  The fracture inducing portion 39 is composed of a small diameter portion in which a part of the end portion of the second main shaft 34 is formed to have a small diameter. Further, a relative rotation prevention pin 40 that prevents relative rotation of both shafts is provided between the first main shaft 33 and the second main shaft 34. The relative rotation prevention pin 40 is inserted from the side surface of the first main shaft 33 and passes through the small hole press-fitting portion 38 that is press-fitted into the small hole portion 36.

  The press-fit strength of the small hole portion 36 and the small hole press-fit portion 38 is set so as to obtain a friction torque larger than the breaking torque of the breakage inducing portion 39, and the large hole press-fit portion 37 of the second main shaft into the large hole portion 35. The press-fitting strength is set so as to slip at a torque smaller than the breaking torque of the breakage inducing portion 39 and not slip under a load in a normal operation state of the compressor.

  In the present embodiment, since the breakage inducing portion 39 is provided between the large hole press-fitting portion 37 and the small hole press-fitting portion 38 of the second main shaft 34, an excessive rotational torque is applied to the main shaft 32 when the compressor is locked. In the case of action, the main shaft 32 is broken from the breakage inducing portion 39, and the external drive source can be reliably protected. In addition, the press-fit strength of the small hole portion 36 and the small hole press-fit portion 38 and the press-fit strength of the large hole press-fit portion 37 to the large hole portion 35 are set as described above, and relative rotation between the shafts 33 and 34 is performed. Since the blocking relative rotation preventing pin 40 is interposed, it is possible to reliably prevent the main shaft 32 from being broken during the normal operation of the compressor.

  FIG. 4 shows a main shaft of a compressor according to the fourth embodiment of the present invention. In this embodiment, since the configuration substantially the same as that of the third embodiment is employed, the same members are denoted by the same reference numerals and the description thereof is omitted. In this embodiment, a resin layer 41 that is more easily worn than the material forming the main shaft 32 is provided between the large hole portion 35 and the large hole press-fitting portion 37 of the second main shaft.

  Also in this embodiment, according to the operation of the third embodiment, it is possible to prevent breakage due to fatigue failure of the main shaft 32 during normal operation of the compressor while ensuring protection of the external drive source when the compressor is locked. . Further, since the resin layer 41 that is more easily worn than the material forming the main shaft 32 is provided between the large hole portion 35 and the large hole press-fitting portion 37, the first main shaft 33 and the second main shaft 33 are locked when the compressor is locked. Since the main shaft 34 is reliably rotated relative to the main shaft 34, the external drive source can be more reliably protected.

  The present invention can be widely applied to a so-called clutchless compressor, and is particularly suitable for a compressor of a vehicle air conditioner.

It is a longitudinal section of a swash plate type compressor as a compressor concerning a 1st embodiment of the present invention. It is a partial expanded sectional view of the main axis | shaft of the compressor of FIG. It is a partial expanded sectional view of the compressor concerning the 2nd embodiment of the present invention. It is a partial expanded sectional view of the compressor concerning the 3rd embodiment of the present invention. It is a partial expanded sectional view of the compressor concerning the 4th embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Swash plate compressor 2 Housing 3 Front housing 3a Tubular part of front housing 4 Cylinder block 4a Cylinder bore 5 Rear housing 6 Crank chamber 7, 32 Main shaft 8 Center hole 9 Needle bearing 10 Rotor 11 Swash plate 12 Needle bearing 13 Swing plate DESCRIPTION OF SYMBOLS 14 Rotation prevention mechanism 15 Piston rod 16 Piston 17 Valve plate apparatus 18 Suction hole 19 Suction chamber 20 Discharge hole 21 Discharge chamber 22 Pulley 23 Ball bearing 24 Screw part 25 Nut 26 Belt 27 Power transmission mechanism 28 Rotation motion conversion mechanism 29, 39 Break Induction part 30 Toroidal member 30a Pulley side press-fitting part of annular member 30b Anti-pulley side press-fitting part of annular member 31, 41 Resin layer 33 First main shaft 34 Second main shaft 35 Large hole part 36 Small hole part 37 Large hole press-fitting part 38 small hole Join the club 40 relative rotation prevention pins

Claims (14)

  A compressor driven by an external drive source, wherein a pulley connected to the external drive source side and a main shaft of the compressor are connected by a power transmission mechanism, and a rotary motion conversion mechanism that converts the rotary motion of the main shaft into a compression motion In the compressor provided with a rupture inducing portion in which the strength of a part of the main shaft is lower than the strength of the other portion on the pulley side of the rotational motion conversion mechanism of the main shaft, A compressor comprising an annular member that covers the rupture inducing portion in the axial direction of the main shaft and is press-fitted into the main shaft at the front and rear portions and has higher torsional rigidity than the rupture inducing portion.   2. The compressor according to claim 1, wherein a press-fitting margin of a pulley-side press-fitting portion is set to be smaller than a press-fitting allowance of an anti-pulley side press-fitting portion with respect to a press-fitting portion before and after the fracture inducing portion of the annular member.   The press-fitting allowance of one press-fitting portion of the annular member is set to a press-fitting allowance that slips with a torque smaller than the rupture torque of the rupture-inducing portion and does not slip under a load in a normal operation state of the compressor, The compressor according to claim 1 or 2, wherein a press-fitting allowance of the other press-fitting portion of the annular member is set to a press-fitting allowance that does not slip under a load in a normal operation state of the compressor.   The layer which consists of a material which wears more easily than the material which forms this main axis | shaft between the at least one press injection part of the said annular member, and the main axis | shaft is interposed. Compressor.   The compressor according to claim 4, wherein the layer made of a material that easily wears is a resin layer.   A compressor driven by an external drive source, wherein a pulley connected to the external drive source side and a main shaft of the compressor are connected by a power transmission mechanism, and a rotary motion conversion mechanism that converts the rotary motion of the main shaft into a compression motion The main shaft is composed of a first main shaft and a second main shaft that are connected to each other on the pulley side with respect to the rotational motion conversion mechanism, and an end of the first main shaft is connected to the shaft of the main shaft. A large hole portion extending in the direction and a small hole portion further extending in the axial direction of the main shaft from the bottom of the large hole portion, and a large hole press-fitted portion press-fitted into the large hole portion at the end of the second main shaft, and the small hole And a small hole press-fitting part press-fitted into the part, and a breakage inducing part is provided between the large hole press-fitting part and the small hole press-fitting part.   The compressor according to claim 6, wherein a press-fitting allowance between the small hole part and the small hole press-fitting part is set to a press-fitting allowance for obtaining a friction torque larger than a breaking torque of the breakage inducing part.   The compressor according to claim 6 or 7, wherein a relative rotation prevention pin for preventing relative rotation of both shafts is provided between the first main shaft and the second main shaft.   The press-fitting allowance between the large hole part and the large hole press-fitting part is set to a press-fitting allowance that slips with a torque smaller than the rupture torque of the rupture inducing part and does not slip under a load in a normal operation state of the compressor. Item 9. The compressor according to any one of Items 6 to 8.   The compressor according to any one of claims 6 to 9, wherein a layer made of a material that is more easily worn than a material forming the main shaft is interposed between the large hole portion and the large hole press-fitting portion.   The compressor according to claim 10, wherein the layer made of the material that easily wears is a resin layer.   The compressor according to any one of claims 1 to 11, wherein the breakage inducing portion is formed of a small diameter portion formed in a part of the main shaft.   The compressor according to any one of claims 1 to 12, wherein the compressor comprises a compressor that converts a rotational motion of a main shaft into a reciprocating motion of a piston.   The compressor according to any one of claims 1 to 12, wherein the compressor has a movable scroll and a fixed scroll, and is composed of a compressor that converts a rotational motion of the main shaft into a turning motion of the movable scroll.

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