JPS645102Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an oil-cooled screw compressor in which a pump is directly connected to the screw rotor shaft.

(Prior Art and Problems) Fig. 1 is a longitudinal cross-sectional view of a conventional oil-cooled screw compressor, in which a screw compressor 1 (hereinafter simply referred to as compressor) and a pump 2 are connected to a prime mover such as an engine or a motor. (not shown) and the male rotor 3 of the compressor 1.
is connected to the prime mover by a coupling (not shown), and the pump rotor 4 of the pump 2 is connected to an Oldham coupling 5.
are directly connected to the male rotor 3 and driven to rotate.

This type of compressor compresses gas in the axial direction by the meshing rotation of a male rotor 3 and a female rotor 6 (not shown in the drawings) that mesh with each other. is compressed in a compression chamber 8 formed by the male rotor 3 and female rotor 6 in the casing 11, discharged from a discharge port 9, and stored in a tank (not shown) via a discharge chamber 34.

Furthermore, the oil for lubrication, sealing, and cooling in the compressor 1 is injected from the discharge port 10 of the pump 2 into the compression chamber 8 through the through hole 35 formed in the casing 11 of the compressor 1, and is compressed from the discharge port 9. It is discharged together with air and sent into the tank.

In addition, a separator is built into the tank to separate air and oil, and the oil accumulated at the bottom of the tank is guided to a cooler and cooled down, and then the oil is cooled at the inlet port of the pump 2.
Reflux and circulate to 2. The high-pressure air from which oil has been removed by the separator is sent from the tank to the compressed air consumption side and consumed.

Furthermore, as shown in FIG. 2, the Oldham joint 5 that connects the pump 2 and the male rotor 3 includes a female type 14 consisting of a slotted groove 13 provided at the tip of the shaft on the rotor side of the pump rotor 4, and a female type 14 that connects the male rotor 3. a female mold 18 consisting of a pin hole 15 and a slotted groove 17 provided on the end face of the pump side shaft in alignment with the axial center position of the male rotor; and a convex portion 1 that fits into the slotted groove 13.
9. It is composed of a cross-shaped male coupling ring 22 consisting of a protrusion 20 that fits into the slotted groove 17 and a pin 21 that fits into the pin hole 15. By fitting the protrusion 20 of the coupling ring 22 into the groove 17 and fitting the protrusion 19 of the coupling ring 22 into the slotted groove 13 of the pump rotor 4, it is directly connected to the male rotor 3.

In the oil-cooled screw compressor using this conventional coupling ring, the slot groove 1 of the male rotor
7. Unless the axes of the slotted groove 13 of the pump rotor, the protrusions 19 and 20 of the coupling ring, etc. are aligned with the center of rotation, smooth operation cannot be achieved. For this reason, in the coupling method using this type of joint, it has been a necessary condition that the axes of the pump rotor 4, Oldham joint 5, and male rotor 3 must be perfectly aligned during machining. Further, in machining the Oldham joint 5, generally, first, the shafts of the pump rotor 4 and the male rotor 3 are machined using a lathe, and then the slotted grooves 13 and 17 are machined using a milling machine. At that time, the setup must be changed from the lathe to the milling machine, and the milling machine must be used to perform complete centering processing.In addition, the shaft end of the relatively long and heavy screw rotor must be machined using the milling machine. In addition, processing the slotted grooves 13, 17, the protrusions 19, 20, the pin 21, the pin hole 15, etc. so that their axes coincide with each other, and processing the protrusion of the coupling ring 22 requires a very large number of man-hours. Was.

In addition, the suction and discharge of a screw compressor, which is a displacement type compressor, is discontinuous, and the suction and discharge of a positive displacement pump such as a trochoid pump, which is normally used as a pump for lubricating oil pressure of the compressor, is also discontinuous. Discontinuous. Therefore, there is a torque fluctuation in both the male rotor and the pump rotor, and the transmission torque of the Oldham joint that connects the two also fluctuates greatly.

Due to this large variation in the transmitted torque, the side surface of the coupling convex portion repeatedly came into contact with the groove surface of the slot groove of the Oldham joint, causing abnormal wear and damage to the slot groove and the convex portion.

Therefore, the materials used for the male and female rotors must also have good wear resistance, which results in poor machinability and increases the number of man-hours required for machining the rotor teeth.

Therefore, in order to withstand the torque fluctuations, conventionally, as shown in FIG. 2, the length L of the slotted groove 17 at the shaft end was increased by fixing the bearing 23 on the male rotor side with a nut 24. However, the length l of the coupling convex portion 20 that fits into this slotted groove is also increased. On the other hand, the pump rotor is made of hardened carbon steel with a high carbon content in order to withstand the torque fluctuations. This reduces the contact stress on the contact surface between the slotted groove and the convex portion, improves the wear resistance, and reduces the wear, but a sufficient effect has not been obtained.

Note that the washer 25 is provided to prevent the nut 24 from rotating.

As described above, in conventional oil-cooled screw compressors, it is extremely difficult to process the coupling part that connects the pump rotor to the male rotor, and it is not possible to sufficiently prevent wear of the coupling part. If it becomes necessary to replace one part, the screw rotor itself, which is the main component of the compressor, must also be replaced, which means that the repair period will be long and the repair cost will be very expensive. It has many problems.

(Purpose of the invention) The present invention was made in view of the above, and it fixes a disc-shaped coupling ring provided with a female spline to the shaft end on the discharge side of the screw rotor, and also fixes a bearing fixing nut that supports the screw rotor. 24 and instead, the disc-shaped coupling is used also for fixing the bearing, thereby shortening the screw rotor shaft itself,
To reduce the overall dimensions of the compressor.

Furthermore, it is easy to process the joint between the rotor shaft and the pump rotor, and even if the joint becomes worn out, it is possible to simply replace the pump rotor and disc-shaped coupling, which are relatively small parts. To provide a low-cost, highly durable oil-cooled screw compressor.

(Structure of the invention) In order to achieve the above object, the present invention provides an oil-cooled screw compressor in which a pump for supplying lubricating oil pressure is directly connected to the screw rotor shaft. A disc-shaped coupling ring having a female spline in the center is provided, and the flange surface of the disc-shaped coupling ring is brought into contact with the end face of the discharge side bearing that supports the screw rotor, thereby fixing it to the rotor shaft. The pump rotor is characterized in that a male spline is formed at the shaft end of the pump rotor, and is fitted with the female spline to drive the oil pump.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

Note that the same symbols are used for the same parts as in FIGS. 1 and 2.

FIG. 3 is a perspective view showing the main parts of the present invention,
Reference numeral 3 denotes a male rotor, and a plurality of tap holes 32 are provided in the circumferential portion of the end surface of the shaft on the discharge side of the male rotor. Reference numeral 23 denotes a bearing fitted to the shaft end on the discharge side of the male rotor 3, and this bearing supports the discharge side of the male rotor 3. 26 is male rotor 3
A disc-shaped coupling is fixed to the discharge side shaft end of the pump rotor 4, and is coupled to and driven by the pump rotor 4. A female spline 27 is provided at the center of the shaft of the coupling, and a female spline 27 is bored in the flange on the outer periphery of the coupling. Bolts 33 are inserted into the plurality of through holes 31 and are screwed into tapped holes 32 provided at the shaft end of the male rotor 3 to be fixed to the rotor shaft. It is configured to limit the movement of the supporting bearing 23 in the axial direction.

Reference numeral 4 denotes a pump rotor, which is provided with a male spline 30 near the shaft end on the male rotor side, and is fitted and coupled to a female spline 27 of a disc-shaped coupling 26 fixed to the male rotor shaft end, and is connected to an oil pump (not shown). to drive.

Moreover, if the contact portion of the disk-shaped coupling ring with the end of the rotor shaft is fitted with a spigot, the centering accuracy during assembly can be further improved.

Further, as shown in FIG. 4, a bolt 28 is provided on the coupling ring 26, and after the washer 25 for preventing rotation is brought into contact with the shaft end side of the bearing 23, the bolt 28 is screwed into the tapped hole 29 of the male rotor 3. In addition, the male rotor 3 and the bearing 23 may be fixed, and in this way, even if the rotor shaft diameter becomes small as in a small machine, the spline diameter of the pump rotor shaft does not need to be made so small. This has the advantage that the contact stress acting on each tooth can be reduced.

As described above, the rotation of the male rotor 3 transmits the power to the pump rotor 4 and drives it, but at this time, the male rotor 3 is affected by the drive torque transmitted to the pump rotor 4 and the load fluctuations applied to the pump itself. Since the accompanying torque fluctuation load can be shared among multiple teeth of the spline,
The contact stress associated with power transmission can be reduced, thereby improving the durability of the joint.

(Effects of the invention) As detailed above, the present invention employs a spline joint structure for driving an oil pump, fixes a disc-shaped coupling ring having a female spline to the male rotor shaft end, and fixes the disc-shaped coupling structure to the male rotor shaft end. By adopting a structure in which the coupling ring doubles as a fixing device in the axial direction of the bearing that supports the male rotor, it is possible to reduce the contact stress on the coupling contact surface, which is the power transmission part, against torque fluctuations applied to the pump rotor. Not only can the durability of the spline be improved, but also the bearing can be securely fixed.

In addition, there is no need to perform complicated machining on the rotor shaft itself as in the past, and since both the pump rotor and the coupling are relatively small parts, machining and heat treatment are easy, resulting in an inexpensive and highly durable coupling. be able to.

Furthermore, even if the spline portion of the coupling ring should become worn out during long-term use, the parts can be easily replaced.

Furthermore, since the fixing nut of the conventionally used male rotor bearing is also eliminated, the structure of the fixing part can be simplified, and the overall length of the compressor can also be reduced. Moreover, since the disc-shaped coupling ring is detachable from the rotor shaft, parts can be replaced in a short time when the spline parts are worn out, and repair costs can be kept low.

[Brief explanation of the drawing]

FIGS. 1 and 2 show a conventional screw compressor, with FIG. 1 being a longitudinal sectional view thereof, and FIG. 2 being a perspective view of the main part of the Oldham joint.
FIG. 3 is a perspective view of essential parts of an embodiment of the present invention,
FIG. 4 shows another embodiment. 1... Screw compressor, 2... Pump,
3...Male rotor, 4...Pump rotor, 5...
Oldham joint, 23...bearing, 26...coupling, 27...female spline, 28...
...Bolt, 29...Tap hole, 30...Male spline.

Claims (1)

[Scope of utility model registration request] In an oil-cooled screw compressor in which a pump for supplying lubricating oil pressure is directly connected and driven to the screw rotor shaft, a disc-shaped coupling having a female spline in the center of the shaft is provided at the discharge side shaft end of the screw rotor, and The flange surface of the disc-shaped coupling ring is brought into contact with the end surface of the discharge side bearing that supports the screw rotor and fixed to the rotor shaft to limit the axial movement of the bearing,
An oil-cooled screw compressor, characterized in that a male spline is formed at the shaft end of the pump rotor, and the male spline is fitted with the female spline to drive the oil pump.