JP6374665B2 - Step-up screw compressor - Google Patents

Description

  The present invention relates to a speed-increasing screw compressor, and more particularly, to a speed-increasing screw compressor that inputs a rotational driving force from a driving source such as an engine or a motor at an increased speed, and supports the drive shaft of the screw rotor. The present invention relates to a speed increasing type screw compressor having a feature in a bearing portion.

  As shown in FIG. 2, in the screw compressor 100 that compresses the compressed gas by engaging and rotating a pair of male and female screw rotors 181 and 182 in a cylinder 173, a male screw rotor 181 and a female screw rotor 182. The rotor shafts on the suction side and the discharge side provided at both ends of each of these are supported by bearings accommodated in bearing holes formed in the casing 170 so as to be rotatable.

  One of the male and female screw rotors 181 and 182 (male screw rotor 181 in the illustrated example) is used as a drive-side screw rotor, and an engine, a motor, and the like are not illustrated with respect to the drive-side screw rotor. In order to be able to input the rotational driving force from the drive source, the suction side rotor shaft of the drive side screw rotor (male screw rotor 181) is configured to protrude through the suction side casing 171 as the drive shaft 183. In addition, a rotational driving force from a driving source can be input via the driving shaft 183.

  In the speed increasing type screw compressor that can increase the rotational driving force from the driving source and input the driving force to the screw rotor 181 on the driving side, the driving gear attached to the output shaft of the driving source ( A driven gear 187 that meshes with a drive shaft 183 is attached to the drive shaft 183 and the driven gear 187 has a smaller diameter than the drive gear, so that the drive gear and the driven gear 187 function as a speed increasing device. , The rotational driving force from the driving source can be increased and input.

  Further, the connection housing 178 provided in the suction side casing 171 of the screw compressor 100 and the drive source housing 195 are connected by a gear case 193, thereby increasing the connection housing 178 and the gear case 193 of the suction side casing 171. A gear chamber 190 is formed in which the above-described driving gear and driven gear 187 that are high-speed devices are accommodated.

  As a bearing for supporting the drive shaft 183 to which the driven gear 187 constituting the speed increasing device is attached, a cylindrical roller bearing 121 is generally adopted, and the attachment is performed as shown in FIGS. A bearing hole 123 formed to receive the cylindrical roller bearing 121 from the gear chamber 190 side to the cylinder 173 side is provided in the suction-side casing 171, and the bearing hole 123 protrudes in the inner circumferential direction from both edges in the width direction. The outer ring 121c, which is both brim rings formed with a brim, is accommodated, the position of the cylinder side end portion of the outer ring 121c is restricted by a locking portion 124 formed in the bearing hole 123, and the snap ring attached to the bearing hole 123 The outer ring 121 c is held in the bearing hole 123 by 125.

  Then, with the roller 121b attached between the collars of the outer ring 121c, the inner ring 121a, which is a flangeless ring fitted on the drive shaft 183, is inserted into the outer ring 121c from the cylinder 173 side, and the roller 121b and the inner ring 121a are connected to the outer ring. The driven gear 187 is attached to the shaft end of the drive shaft 183 that is disposed in the shaft 121c and protrudes toward the gear chamber 190 through the bearing hole 123, so that the boss 187a and the drive shaft 183 of the driven gear 187 are attached. The inner ring 121a of the cylindrical roller bearing 121 is sandwiched and fixed between the provided locking portions 183b (FIG. 4 of Patent Document 1).

Japanese Patent No. 3349872

  In the screw compressor 100 configured as described above, the bearings that support the screw rotors 181 and 182 are deteriorated in function due to wear due to aging, and therefore need to be periodically replaced.

  Here, the screw compressor 100 is used by being housed in a soundproof box (not shown) together with a drive source (not shown) such as an engine and a motor and other components (not shown). The sound box is provided with an inspection window and an inspection door that opens and closes the inspection box, and maintenance and inspection work for the accommodation equipment is usually performed through the inspection window.

  However, in the conventional speed-increasing screw compressor 100 that employs the bearing portion structure of the drive shaft 183 described with reference to FIGS. 2 and 3, the replacement of the cylindrical roller bearing 121 that supports the drive shaft 183 is prevented. It was not possible to perform the inspection through the inspection window provided in the sound box, and it was necessary to take out the screw compressor 100 from the soundproof box and perform the replacement work.

  That is, in the speed increasing type screw compressor 100, the driven gear 187 constituting the speed increasing device is attached to the drive shaft 183 as described above, and the suction side casing 171 of the screw compressor 100 and the drive The source housing 195 is connected by a gear case 193 to form a gear chamber 190 that accommodates a driving gear and a driven gear 187 as a speed increasing device.

  On the other hand, in the bearing portion 120 that supports the drive shaft 183 of the screw compressor 100 shown in FIGS. 2 and 3, in order to remove the cylindrical roller bearing 121, the drive shaft 183 needs to be extracted from the bearing hole 123. Since the driven gear 187 is attached to 183, the drive shaft 183 cannot be extracted from the bearing hole 123 as it is.

  Even if the drive shaft 183 can be extracted from the bearing hole 123, in order to replace the cylindrical roller bearing 121, it is necessary to remove the outer ring 121c attached in the bearing hole 123.

  Since the operation of removing the driven gear 187 from the drive shaft 183 and the operation of removing the outer ring 121c from the bearing hole 123 are both operations that can be performed only from the gear chamber 190 side, FIG. In the conventional speed-increasing screw compressor 100 described with reference to FIG. 3, the operation of opening the gear chamber 190 is indispensable for the replacement of the cylindrical roller bearing 121 that supports the drive shaft 183, and the screw compression is performed in the soundproof box. The replacement work cannot be performed in a state in which the machine 100 is accommodated. In the work, first, the space required for taking out the screw compressor 100 is secured by, for example, removing the exterior panel of the soundproof box. The connecting bolt 197 that connects between the source housing 195 and the gear case 193 is removed so that the screw compressor 100 can be disconnected from the drive source. In addition, that take out the screw compressor 100 out of the soundproof box is lifted by a crane or the like, it is necessary to large-scale work.

  In addition, since it is necessary to take out the screw compressor 100 from the soundproof box in this way, not only preparation of a lifting device such as a crane is necessary, but also the removed screw compressor 100 is held in a stable state. A fixing tool (preferably a reversing work tool capable of reversing the screw compressor 100) has to be prepared, and corresponding equipment is required for the bearing replacement work.

  Further, since the screw compressor 100 is taken out of the soundproof box, there is a space for temporarily placing parts such as the screw compressor 100 taken out, the driven gear 187 removed from the screw compressor 100, the screw rotors 181, 182 and the like. If it is necessary to secure such a space, it is necessary to secure the extracted screw compressor 100 when it is not possible to secure such space on the compressor installation / use site, such as an outdoor civil engineering building site or factory compressor installation space. It must be transported to a factory or the like, and the compressor stop time becomes longer, which greatly affects the work process using compressed air.

  Accordingly, the present invention has been made to eliminate the above-mentioned drawbacks of the prior art, and accommodates the screw compressor in a soundproof box and does not open the gear chamber and the casing and the drive source of the screw compressor. A screw compressor that can easily replace the bearing that supports the drive shaft of the screw compressor through an inspection window provided in the soundproof box, etc., while maintaining the connection between the housings. The purpose is to provide.

  Hereinafter, means for solving the problem will be described together with reference numerals used in the embodiment for carrying out the invention. This code is used to clarify the correspondence between the description of the scope of claims and the description of the mode for carrying out the invention. Needless to say, it is used in a limited manner for the interpretation of the technical scope of the present invention. It is not a thing.

In order to achieve the above object, the speed increasing type screw compressor 1 of the present invention comprises:
A pair of male and female screw rotors 81, 82 that discharge while compressing fluid to be compressed introduced from the suction side toward the discharge side by meshing and rotating in a cylinder 73 formed in the casing 70, and each of the screws. Bearing portions 20, 30, 40, 50 for respectively supporting rotor shafts 83 to 86 provided at both ends of the rotors 81, 82, respectively, and one of the male or female screw rotors 81, 82. The rotor shaft provided on the suction side of the rotor (male screw rotor in the present embodiment) 81 passes through the suction side wall surface of the casing 70 and protrudes outside the casing to form a drive shaft 83, and the output of the drive source A speed increasing screw compressor 1 having a driven gear 87 meshing with a driving gear (not shown) provided on the shaft attached to the driving shaft 83 is provided. Stomach,
The casing 70 includes a casing main body 71 in which the cylinder 73 is formed, and a discharge side casing 72 that covers the discharge side end of the cylinder 73 and is detachably attached to the casing main body 71.
A bearing portion 20 that supports the drive shaft 83 is provided with a through hole 23 formed in the casing body 71 and a cylindrical roller bearing 21 that is fitted in the through hole 23 and fitted on the drive shaft 83. Prepared,
The cylindrical roller bearing 21 is larger than the outer diameter (the diameter of the addendum circle) of the inner ring 211, which is a double collar formed with ribs protruding in the outer circumferential direction from both end edges in the width direction, and the driven gear 87. An outer ring 212 having an inner diameter and not including a collar protruding in the inner circumferential direction at an end on the cylinder 73 side (in the illustrated example, a ring without a collar);
The through hole 23 includes an outer ring mounting portion 23a formed in a width W equal to or larger than the width w of the outer ring 212, which receives and fits the outer ring 212 from the cylinder 73 side, and the cylinder 73 side of the through hole 23 A member that is formed near the end opposite to the outer diameter of the driven gear 87 and smaller in diameter than the outer diameter of the outer ring 212 and protrudes in the inner peripheral direction of the through hole 23. A stop 23b ,
The drive shaft 83 can be pulled out together with the driven gear 87 toward the cylinder 73 through the through-hole 23 without removing the driven gear 87 (Claim 1).

  When the outer ring 212 is a brimless ring that is not formed on either end edge in the width direction, a locking tool 25 such as a snap ring that restricts the position of the end of the outer ring 212 on the cylinder 73 side is attached to the outer ring 212. It attaches to the attaching part 23a so that attachment or detachment is possible (Claim 2).

  The drive shaft 83 is provided with an inner ring attachment portion 83a for fitting the inner ring 211 and a large diameter portion 83b formed on the rotor side with respect to the inner ring attachment portion 83a, and an end surface of the large diameter portion 83b. The inner ring 211 may be fixed to the drive shaft 83 by sandwiching the inner ring 211 between end faces of the bosses 87a provided on the driven gear 87 (Claim 3).

  According to the configuration of the present invention described above, in the speed increasing type screw compressor 1 of the present invention, the discharge side casing 72 is detached from the casing body 71 without removing the driven gear 87 from the drive shaft 83, and together with the screw rotor 81. By pulling out the drive shaft 83 toward the cylinder 73, the drive shaft 83 can be extracted from the through hole 23 together with the inner ring 211 and the driven gear 87.

  Further, after the drive shaft 83 was removed, the outer ring 212 remaining in the through hole 23 could be removed from the cylinder 73 side.

  As a result, when the cylindrical roller bearing 21 of the drive shaft 83 of the screw compressor 1 is replaced, the gear chamber 90 is opened, that is, the connection between the drive source housing (not shown) and the gear case 93 is released. There is no need to replace the cylindrical roller bearing 21 that supports the drive shaft 83 while the screw compressor 1 is housed in the soundproof box, and a large-scale work such as taking the screw compressor 1 out of the soundproof box is possible. It became unnecessary, and the compressor stop time associated with bearing replacement was shortened.

  Even if the outer ring 212 is configured as a collarless ring by providing a locking tool 25 such as a snap ring that regulates the position of the end of the outer ring 212 on the cylinder side, the outer ring 212 is provided in the outer ring mounting portion 23a. It could be held at a predetermined position and prevented from falling off due to the movement of the outer ring 212.

  The outer ring 212 is not provided with a flange projecting in the inner circumferential direction at the end on the cylinder 73 side, but is a single collar ring provided with a collar projecting in the inner circumferential direction on the edge on the gear chamber 90 side. For example, one collar is engaged with the roller 213, the roller 213 is held by both collars of the inner ring 211, and the inner ring 211 is locked by a large diameter portion 83b formed on the rotor side of the inner ring mounting portion 83a. 212 is not only restricted to the gear chamber 90 side by the locking portion 23b but also restricted to the cylinder 73 side and is held at a predetermined position in the outer ring attachment portion 23a. There is no need to provide the locking tool 25.

  Further, when the inner ring 211 is sandwiched between the end surface of the large-diameter portion 83 b provided on the drive shaft 83 and the end surface of the boss 87 a of the driven gear 87, the drive-side screw rotor 81 is removed from the screw compressor 1. After that, by removing the driven gear 87 from the drive shaft 83, the inner ring 211 can be easily removed.

Cross-sectional explanatory drawing of the speed increasing type screw compressor of this invention. Cross-sectional explanatory drawing of the conventional speed increasing type screw compressor. FIG. 3 is an enlarged view of a bearing portion of a drive shaft in the speed increasing type screw compressor of FIG. 2.

  Hereinafter, the speed-increasing screw compressor 1 of the present invention will be described with reference to the accompanying drawings.

[Overall structure of speed increasing screw compressor]
The speed increasing type screw compressor 1 is configured such that a pair of male and female screw rotors 81 and 82 are rotatably accommodated in a cylinder 73 provided in a casing 70 so as to be engaged with each other. Is rotated in an engaged state in the cylinder 73 to introduce and close the compressed gas into the compression working space defined by the tooth grooves of the screw rotors 81 and 82 and the inner wall of the cylinder 73, and As a result of the volume of the compression working space decreasing with the rotation of the screw rotors 81 and 82, the closed compressed gas is compressed and discharged.

  In the illustrated embodiment, the casing 70 is covered with a casing body 71 in which a cylinder 73 and a portion that closes the suction side end of the cylinder 73 are integrally formed, and a discharge side end of the cylinder 73 is covered. However, the discharge casing 72 is detachably attached to the casing main body 71. However, instead of this configuration, the casing is similar to the conventional compressor main body described with reference to FIG. 170 may be constituted by three members: a cylinder 173, a discharge-side casing 172 that closes the discharge-side end of the cylinder 173, and a suction-side casing 171 that closes the suction-side end of the cylinder.

  In order to enable introduction of compressed gas into the compression working space defined by the tooth gap formed in the pair of male and female screw rotors 81 and 82 and the inner peripheral surface of the cylinder 73, The casing 70 (casing body 71) is formed with an inlet port 74 and a suction channel 75 continuous to the inlet port 74. The suction channel 75 is connected to the inlet side of the male and female screw rotors 81 and 82. By opening toward the end face, the compressed gas can be introduced into the compression working space described above.

  In the description of the present invention, the end face side of the rotors 81 and 82 communicating with the suction passage 75 is referred to as “suction side”, and the opposite side to the suction side is referred to as “discharge side”.

  The pair of male and female screw rotors 81 and 82 are provided with rotor shafts 83 to 86 projecting from both ends of the screw rotors 81 and 82, and the rotor shafts 83 to 86 are connected to the above-described rotor shafts 83 to 86, respectively. The screw rotors 81 and 82 can be smoothly rotated by being rotatably supported by bearings 20, 30, 40, and 50 formed in the casing 70.

  In the illustrated example, a male screw rotor 81 is formed so as to drive and rotate a female screw rotor 82, and a suction side rotor shaft protruding from the suction side end surface of the male screw rotor 81 is used for an engine or motor not shown. A drive shaft 83 to which a rotational drive force is input from a drive source such as a drive shaft 83 is configured such that the drive shaft 83 penetrates the suction side wall surface of the casing 70 and protrudes outside the casing. The rotor 82 may be configured to drive and rotate the male screw rotor 81. In this case, the suction side rotor shaft provided on the suction side end surface of the female screw rotor is used as a drive shaft, and this drive shaft serves as the casing 70. It penetrates the suction side wall surface and protrudes outside the casing.

  A drive gear 87 constituting a speed increasing device is attached to the drive shaft 83, and the drive gear 87 is attached to an output shaft of a drive source such as an engine or a motor (not shown). The rotational driving force from the drive source can be increased and input to the screw compressor 1 by being engaged with the screw compressor 1.

  Note that the connection housing 78 on the suction side of the casing body 71 is connected to a drive source housing (not shown) via a gear case 93, and a gear chamber is provided inside the connection housing 78 and the gear case 93 on the suction side of the casing body 71. 90 is formed, and the above-described driving gear and driven gear 87 constituting the speed increasing device are accommodated in the gear chamber 90.

  Of the bearing portions 20, 30, 40, 50 for supporting the rotor shafts 83 to 86 provided on the male screw rotor 81 and the female screw rotor 82, the structure of the bearing portions 30, 50 provided on the discharge side is known. In the example shown in the figure, cylindrical roller bearings 31 and 51 having a high load capacity with respect to a radial load and an angular ball bearing 32 capable of receiving an axial load. 52 is combined and accommodated in the bearing holes 33 and 53 to form a discharge-side bearing.

  As long as the configuration of the bearing portions 30 and 50 on the discharge side can receive both a radial load and an axial load, other known configurations may be adopted, for example, two angular balls You may use it combining a bearing in the reverse direction.

  Further, the structure used in a known screw compressor can also be adopted for the bearing portion 40 of the suction-side rotor shaft 85 of the driven-side screw rotor (female screw rotor in the illustrated example) 82. In the embodiment, the outer ring 412 that is a rib that protrudes in the inner circumferential direction from the peripheral edges at both ends in the width direction, and the collar that protrudes in the outer circumferential direction only at the edge on the cylinder 73 side are formed. A cylindrical roller bearing 41 having an inner ring 411 that is a single collar ring is fitted in a bearing hole 43 that is a bottomed hole that opens toward the cylinder 73 side, and is fitted on the suction-side rotor shaft 85. Yes.

[Configuration of bearing section of drive shaft]
Also in the structure of the bearing portion 20 of the drive shaft 83 which is a characteristic part of the speed-increasing screw rotor 1 of the present invention, the through hole 23 formed in the casing 70 (casing body 71) and the through hole 23 are inserted. 2 and FIG. 3 as a prior art in that the drive shaft 83 and the cylindrical roller bearing 21 fitted inside the through-hole 23 and fitted outside the drive shaft 83 are provided. This is the same as the bearing 120 of the drive shaft 183 of the speed increasing screw compressor of Patent Document 1 described.

  However, in the bearing portion 20 of the drive shaft 83 in the screw compressor 1 according to the present invention, the inner ring of the cylindrical roller bearing 21 is configured as a double bridging ring formed with ribs protruding in the outer circumferential direction from both end edges in the width direction. The outer ring 212 has an inner diameter larger than the outer diameter (the diameter of the tip circle) of the driven gear 87, and is not provided with a flange protruding in the inner circumferential direction at least at the end of the cylinder. It is configured as a ring or a collarless ring (in the example shown, a collarless ring).

  The through-hole 23 is provided with an outer ring mounting portion 23a formed to have a width W equal to or greater than the width w of the outer ring 212, which receives and fits the outer ring from the cylinder 73 side, and the cylinder 73 of the through-hole 23 Near the end on the opposite side (the gear chamber 90 side), the inner diameter of the through hole 23 is formed larger than the outer diameter of the driven gear 87 and smaller than the outer diameter of the outer ring 212. A locking portion 23b projecting in the circumferential direction is provided, and the end of the outer ring 212 on the side of the gear chamber is abutted against the end surface of the locking portion 23b. In the illustrated example, the end surface of the outer ring 212 on the cylinder 73 side is connected to the outer ring. It is made to abut on a locking tool (snap ring) 25 fitted in a fitting groove 26 provided in the attachment portion 23a and is held in the outer ring attachment portion 23a.

  In the illustrated embodiment, an inner ring attachment portion 83a for fitting the inner ring 211 to the drive shaft 83 is provided, and a large diameter portion 83b is provided at a position closer to the rotor with respect to the inner ring attachment portion 83a. By sandwiching the inner ring 211 between the end face of 83b and the end face of the boss 87a of the driven gear 87, the inner ring 211 is moved to the drive shaft 83 so that the inner ring 211 does not move in the axial direction of the drive shaft 83. It is fixed on the top.

  Thus, after the male screw rotor 81 is removed from the screw compressor 1 by sandwiching and fixing the inner ring 211 between the end surface of the large diameter portion 83b and the end surface of the boss 87a of the driven gear 87, the drive shaft 83 The inner ring 211 can be removed simply by removing the driven gear 87 from the wheel.

[Action etc.]
In the screw compressor 1 of the present invention configured as described above, when the cylindrical roller bearing 21 that supports the drive shaft 83 is replaced, the connecting bolt 76 that fixes the discharge-side casing 72 to the casing body 71 is removed. The discharge side casing 72 is removed from the casing body 71.

  When removing the discharge-side casing 72, the end cover 77 attached to the discharge-side casing 72 is removed in advance, and the end plates 89b attached to the shaft ends of the discharge-side rotor shafts 84 and 86 are removed. Thus, only the discharge-side casing 72 may be removed with the screw rotors 81 and 82 left in the cylinder 73, and then the screw rotors 81 and 82 accommodated in the cylinder 73 may be removed. The screw rotors 81 and 82 may be removed from the cylinder 73 simultaneously with the removal of the discharge-side casing 72 without removing the part cover 77 and the end plate 89b.

  The outer ring 212 of the cylindrical roller bearing 21 that supports the drive shaft 83 is sandwiched between the end face of the locking portion 23b provided in the through hole 23 and the snap ring 25 that is a locking tool, and is attached to the outer ring in the through hole 23. Although the outer ring 212 is fixed in the inner ring 23a, the outer ring 212 is not formed with a collar projecting in the inner circumferential direction at least at the end on the cylinder 73 side. Therefore, when the male screw rotor 81 which is the screw rotor on the driving side is pulled out from the cylinder 73, the inner ring 211 and the rollers 213 held between the collars of the inner ring 211 are removed from the outer ring 212. It can be pulled out together with the drive shaft 83 to the cylinder 73 side.

  At this time, although the driven gear 87 is still attached to the driving shaft 83, the outer diameter (tooth tip circle diameter) of the driven gear 87 is larger than the inner diameter of the outer ring 212 and the inner diameter of the locking portion 23b. Since it is formed in a small diameter, the drive shaft 83 with the driven gear 87 attached can be pulled out through the outer ring 212 to the cylinder 73 side, and when the drive shaft 83 is pulled out to the cylinder 73 side, It is not necessary to remove the driven gear 87 from the drive shaft 83, and therefore the screw rotor 81 can be extracted from the cylinder 73 without opening the gear chamber 90.

  Thus, after extracting the male screw rotor 81 from the cylinder 73, the outer ring mounting portion of the through hole 23 is inserted by inserting a hand or a tool into the cylinder 73 opened by removing the discharge-side casing 72. The snap ring 25 attached to 23a is removed, and the outer ring 212 of the cylindrical roller bearing 21 remaining in the through hole 23 is removed.

  Further, the driven gear 87 is removed from the drive shaft 83 of the male screw rotor 81 extracted from the cylinder 73 and held between the inner ring 211 of the cylindrical roller bearing 21 attached to the drive shaft 83 and the collar of the inner ring 211. Removal of the used roller 213 completes removal of the used cylindrical roller bearing 21.

  In this way, after the removal of the used cylindrical roller bearing 21 is completed, the outer ring mounting portion of the through hole 23 in which the outer ring 212 of the new cylindrical roller bearing 21 is formed in the casing body 71 in the reverse procedure. The inner ring 211 that is fitted into the inner ring 23a and fixed by attaching the snap ring 25 and holding the rollers 213 between the collars is fitted into the inner ring attaching portion 83a of the drive shaft 83, and then the driven gear 87 is attached to the drive shaft 83. Attach and fix the inner ring 211 between the end surface of the large-diameter portion 83b and the end surface of the boss 87a of the driven gear 87, and in this state, insert the male screw rotor 81 from the discharge side end of the cylinder 73, The roller 213 and the inner ring 211 are disposed in the outer ring 212 together with the drive shaft, and the discharge-side casing 72 is fixed to the casing body 71 with a connecting bolt 76, thereby driving the motor. Replacement of the cylindrical roller bearing 21 for supporting the shaft 83 is completed.

  As described above, in the screw compressor 1 of the present invention, the male screw rotor 81 is extracted from the cylinder 73 only by the operation from the discharge side of the screw compressor 1, and thus the cylindrical roller bearing for the drive shaft 83 is obtained. 21 and the roller 213 held between the collars provided on the inner ring 211 can be taken out, and the outer ring 212 remaining in the through hole 23 can also be removed by work from the discharge side. As a result, when replacing the cylindrical roller bearing for the drive shaft as in the case of the screw compressor described as the prior art with reference to FIG. 2 and FIG. 3, the work of removing the screw compressor from the soundproof box is not required. Therefore, removing the outer panel of the soundproof box, removing the connection between the drive source and the screw compressor, removing the screw compressor with a crane, etc. Such as work and the like to issue, complicated operation is not required.

  As a result, when replacing the cylindrical roller bearing that supports the drive shaft, it is not necessary to prepare a lifting device such as a crane or a fixture that holds the removed compressor body, and the space for removing the discharge casing and screw rotor is eliminated. Therefore, it is possible to perform replacement work from an opening such as an inspection window provided in the soundproof box.

  In addition, it is possible to replace the bearing at the site where the compressor is installed, eliminating the need to carry out the removed screw compressor to a maintenance shop, etc., so that the compressor stop time can be shortened and compressed air can be reduced. The influence on the work process to be used can be reduced.

  Furthermore, in the configuration of the conventional screw compressor described with reference to FIG. 2, the driven gear must be removed with the drive shaft and the casing assembled. The gear is surrounded by the suction side wall of the casing body where the bearings are attached and the connecting housing provided on the suction side of the casing body. Since it is difficult to use a method such as heating and removing the motor, the fitting between the drive shaft and the driven gear mainly uses a clearance fit or intermediate fit for easy attachment / detachment of the driven gear. It was.

  On the other hand, in the screw compressor of the present invention, the drive-side rotor can be removed from the cylinder with the driven gear fitted to the drive shaft. 1 and the driven gear 87 can be attached and detached by using a method such as heating. Therefore, the driven gear 87 is connected to the end plate as shown in FIG. It is not limited to pressing from the shaft end of the drive shaft 83 to the rotor side by the 89a and the end plate fixing bolts 88, and it is also easy to adopt a fit fit between the drive shaft and the driven gear.

  By using interference fit, the power transmitted from the drive gear provided on the output shaft of the drive source to the driven gear can be reliably transmitted to the drive shaft. In this case, the key and key groove processing and spline processing that are provided on the outer surface of the drive shaft and the inner surface of the boss of the driven gear to perform such power transmission are not required, and the number of processing steps can be reduced. At the same time, the width of the driven gear and the length of the rotor shaft in the axial direction can be shortened, and the end plate 89a and the end plate fixing bolt 88 at the end of the drive shaft 83 are not required, thereby reducing the size of the compressor body. be able to.

1 Screw compressor 20 Bearing (male rotor suction side)
21 Cylindrical roller bearing 211 Inner ring 212 Outer ring 213 Roller 23 Through hole 23a Outer ring mounting part 23b Locking part 25 Locking tool (snap ring)
26 Fitting groove 30 Bearing (male rotor discharge side)
31 Cylindrical roller bearing 32 Angular contact ball bearing 33 Bearing hole 40 Bearing section (female rotor suction side)
41 Cylindrical roller bearing 411 Inner ring 412 Outer ring 413 Roller 43 Bearing hole 50 Bearing part (female rotor discharge side)
51 Cylindrical Roller Bearing 52 Angular Ball Bearing 53 Bearing Hole 70 Casing 71 Casing Body 72 Discharge Side Casing 73 Cylinder 74 Suction Port 75 Suction Channel 76 Connection Bolt 77 End Cover 78 Connection Housing 81 Male Screw Rotor (Drive Side)
82 Female screw rotor (driven side)
83 Drive shaft [suction side rotor shaft (male rotor)]
83a Inner ring mounting portion 83b Large diameter portion 84 Discharge side rotor shaft (male rotor)
85 Suction side rotor shaft (of female rotor)
86 Discharge side rotor shaft (for female rotor)
87 Driven gear 87a Boss (of driven gear)
88 End plate fixing bolt 89a End plate (for drive shaft)
89b End plate (of discharge side rotor shaft)
DESCRIPTION OF SYMBOLS 90 Gear chamber 93 Gear case 100 Screw compressor 120 Bearing part 121 Cylindrical roller bearing 121a Inner ring 121b Roller 121c Outer ring 123 Bearing hole 124 Locking part 125 Snap ring 170 Casing 171 Suction side casing 172 Discharge side casing 173 Cylinder 178 Connection housing 181 Male Screw rotor (drive side)
182 Female screw rotor (driven side)
183 Drive shaft 183b Locking portion 187 Driven gear 187a Boss 190 Gear chamber 193 Gear case 195 Housing (for drive source)
197 connecting bolt

Claims (3)

A pair of male and female screw rotors that discharge while compressing the fluid to be compressed introduced from the suction side toward the discharge side by meshing and rotating in a cylinder formed in the casing, and both ends of each screw rotor. A bearing portion for supporting each of the provided rotor shafts, and the rotor shaft provided on the suction side of one of the male or female screw rotors passes through the suction side wall surface of the casing. A speed increasing type screw compressor in which a drive gear is mounted on the drive shaft while projecting externally to be a drive shaft and meshed with a drive gear provided on an output shaft of a drive source.
The casing includes a casing body in which the cylinder is formed, a discharge side casing that covers the discharge side end of the cylinder and is detachably attached to the casing body;
A bearing portion for supporting the drive shaft includes a through hole formed in the casing body, and a cylindrical roller bearing fitted into the through hole and fitted to the drive shaft;
The cylindrical roller bearing has an inner ring which is a double-branched ring formed with flanges protruding in the outer circumferential direction from both end edges in the width direction, an inner diameter larger than the outer diameter of the driven gear, and at least an end on the cylinder side An outer ring without a flange protruding in the inner circumferential direction is provided at the edge,
The through-hole includes an outer ring mounting portion formed to have a width equal to or greater than the width of the outer ring, which receives and fits the outer ring from the cylinder side, and is closer to the end of the through-hole opposite to the cylinder side. A locking portion that is larger than the outer diameter of the driven gear and smaller than the outer diameter of the outer ring and protrudes in the inner circumferential direction of the through hole ;
A speed increasing type screw compressor characterized in that the drive shaft can be pulled out together with the driven gear to the cylinder side through the through hole without removing the driven gear .   The outer ring is formed as a brimless ring in which no flange is formed on either end edge in the width direction, and a locking tool for restricting the position of the end of the outer ring on the cylinder side is detachably attached to the outer ring mounting part. The speed increasing type screw compressor according to claim 1. The drive shaft includes an inner ring mounting portion that externally fits the inner ring, and a large diameter portion formed on the rotor side with respect to the inner ring mounting portion, and a boss provided on an end surface of the large diameter portion and the driven gear The speed increasing type screw compressor according to claim 1 or 2, wherein the inner ring is fixed to the drive shaft by sandwiching the inner ring between the end surfaces of the screw.

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