JPS597052B2 - Electromagnetic clutch support structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compressor that is driven by transmitting an external driving force, and particularly relates to a structure of a supporting part of a driving force transmitting device that is supported at an end of the compressor and that transmits power to a main shaft. It is related to.

As shown in Fig. 1, the conventional structure for attaching an electromagnetic clutch to an axial type compressor includes a cylindrical protrusion 5 that encloses a main shaft 3' in the outer end surface of a front housing 2' and protrudes from the front.
' is formed integrally with the front housing 2', and a ball bearing 10' is press-fitted onto the outside of the cylindrical projection 5',
The rotor portion 12' of the electromagnetic clutch is rotatably supported, or a ball bearing 10'' is used as shown in FIG.
The core 1 containing the excitation coil is press-fitted into the sleeve 5".
A structure in which the core 17'' is formed integrally with the front housing 2'' and is fixed on the outer end surface of the front housing 2'' has been known.

Generally, the shape of the electromagnetic clutch installed in the compressor is determined once the diameter of the ball bearing is determined.

In other words, once the diameter of the ball bearing is determined, the coil space required to obtain the magnetomotive force of the coil required to transmit power to the compressor is determined, and if a thickness restriction is given, the coil diameter is determined. is determined, and the thickness of the inner and outer diameter parts of the rotor part is determined in order to suppress the magnetic resistance or magnetic saturation of the magnetic circuit to a predetermined value or less, then the minimum diameter of the mouth part including the pulley is uniquely determined. It will be put away.

As the diameter of the ball bearing increases, the circumferential speed of the ball bearing increases for a given number of rotations, which determines the service life that can be obtained with respect to belt tension and transmission torque load.

Therefore, by reducing the diameter of the ball bearing, the service life can be improved, and the average radius of the winding of the coil can be reduced, which results in a reduction in the resistance of the winding. can reduce the windings.

In addition, the inner race of the ball bearing that fits on the outside of the cylindrical protrusion and rotatably supports the rotor of the electromagnetic clutch is designed to prevent axial movement between the end faces of the snap ring disposed on the protrusion. Although the inner race was held in a pinched position, any relative movement between the cylindrical protrusion and the inner race would have a major impact on the cylindrical protrusion and also affect the life of the ball bearing, so no rotational movement would occur on the inner race. This was a desirable configuration.

If the device structure is such that the front housing and the cylindrical protrusion are integrally formed, the shaft seal mechanism can be easily inserted into the cylindrical protrusion, and if the protrusion is thick enough, it can be used as an electromagnetic clutch. However, in order to reduce the weight of the entire compressor, when the front housing is made of aluminum alloy, the protrusions must be formed to have a cylindrical shape that can withstand the tension of the drive belt. The wall thickness had to be increased, and as a result, the diameter of the ball bearing press-fitted onto the outer periphery of the cylindrical projection was increased, and the diameter of the electromagnetic clutch was also increased.

If a front housing made of cast iron was used to reduce the diameter of the electromagnetic clutch, the weight of the entire compressor would increase.

In addition, axial movement of the ball bearing is prevented by a snap ring installed at the end of the cylindrical projection, but rotation of the inner race is prevented by precision machining of the outer surface of the projection and the inner diameter surface of the inner race in a cast iron front housing. This is controlled by press-fitting both of them, and when the front housing is made of aluminum alloy, even if there is a gap between the inner race and the protrusion at room temperature, the heat in the aluminum alloy due to the temperature rise caused by the compressor drive will be absorbed. The inner race was configured to be securely fixed by expansion, but in the case of a cast iron front housing, the weight increased and machining became difficult, and in the case of an aluminum alloy front housing, the diameter of the electromagnetic clutch It had become something big.

In a structure where a cylindrical protrusion is integrally formed on a core containing a coil and fixed to the end face of the front housing with bolts, etc., the core may be fixed with multiple bolts etc. to withstand the tension of the drive belt. Since there is no seal between the shaft seal mechanism and the front housing, the shaft seal mechanism cannot be inserted into the cylindrical protrusion, and the shaft seal mechanism must be built into the front housing. Therefore, when replacing the shaft seal mechanism, an electromagnetic clutch is required. had to be removed from the compressor.

The inner race of the ball bearing is fixed by forming a threaded portion 30 on the outer end of the cylindrical protrusion 5'' as shown in Fig. 3, and after inserting the ball bearing 10'', screwing a nut 31 onto the inner side of the bearing. With a configuration that presses the race 10a,
A mechanism such as a nut locking mechanism 32 must be added, making the structure complicated.

The present invention aims to reduce the overall weight of a compressor equipped with an electromagnetic clutch and to reduce the required maximum diameter of the electromagnetic clutch by improving the support part of the electromagnetic clutch attached to the compressor. be.

Another object of the present invention is to improve the ease of mounting and serviceability of an electromagnetic clutch and a shaft seal mechanism.

Yet another object of the invention is to reduce the manufacturing cost of compressors.

The present invention will be explained below with reference to drawings showing embodiments.
The figure is a sectional view showing an embodiment of the present invention. The front housing 2 made of aluminum alloy has an opening 2a formed at the end of the compressor main body 1 that passes through the main shaft 3 and supports the main shaft 3 with a radial bearing 4. to be placed.

A protruding part 2C is formed on the outer end surface 2b of the front housing 2 so as to surround the opening 2a, and a cylindrical part 5a that protrudes from the opening 2a and houses the main shaft 3;
A sleeve 5 is formed by fixing a flange body 5b which extends in the radial direction on the outer side of the end of the front housing 2 and has a stepped portion 5c formed on the flange surface facing the protrusion 2c of the front housing 2.
are arranged on the outer end surface of the front housing 2, and the stepped portion 5c is engaged with the protrusion 2c, the sleeve 5 is securely positioned on the front housing 2, and the flange surface of the flange body 5b is secured with bolts 6 or the like. The sleeve 5 is fixed by being fixed to the front housing outer end surface 2b.

Note that the sleeve 5 may have the cylindrical portion 5a and the flange portion 5b integrally formed, and the outer end surface 2bQ of the front housing 2
The space between the sleeve 5 and the flange body 5b is sealed by inserting a sealing member 7 into a concave portion 2d formed on the outer end surface 2b concentrically with the opening 2a.

A seal chamber 8 is formed between the inner surface of the cylindrical portion 5a of the sleeve 5 and the main shaft 3, and a shaft seal mechanism 9 is inserted into the seal chamber 8 to seal the compressor.

A ball bearing 10 is fitted onto the outside of the cylindrical portion 5a of the sleeve 5, and a rotor portion 1 of an electromagnetic clutch 11 is fitted onto the outside.
2 is rotatably supported.

The inner race 10a of the ball bearing 10 is held between the end face of the flange portion 5b and a snap ring 13 disposed at the outer end of the cylindrical portion 5a to prevent movement in the axial direction and to prevent relative movement with the cylindrical portion 5a. This is prevented by a rotation prevention mechanism 14 formed between the end face of the flange portion 5a and the end face of the inner race 10a.

The outer race 10b is press-fitted into the inner diameter surface of the rotor section 12 and has a protrusion 12a formed on the inner diameter surface of the rotor section 12 for axial movement, and a snap ring 15 disposed on the end surface of the inner diameter surface.
This is prevented by sandwiching the outer race 10b between them.

The rotor part 12 consists of concentric double cylinders 121, 122 and a friction surface 123 that joins the double cylinders, and on the outer periphery of the outer cylinder 121 there is a V-belt groove 121 for tensioning the driving V-belt.
a, concentric double cylinders 121, 122 and friction surface 123
A core 17 that encloses the excitation coil 16 in a U-shaped cross section is disposed within the internal space 12a formed by the above.

The core 17 is arranged concentrically with other rotating members by fixing a fixing plate 19, which is sandwiched between the snap ring 18 disposed on the outside of the flange portion 5b and the flange surface, to the end surface. It is set up.

A clutch hub 22 having a flange surface 22a in the radial direction fixed by a key 20 and a nut 21 is disposed at the end of the main shaft 3 protruding outward from the cylindrical portion 5a of the sleeve 5,
On the outer periphery of the flange surface 22a of the clutch hub 22, an armature plate 23 is disposed with a gap therebetween, facing the friction surface 123 of the rotor section 12 with a certain gap therebetween.

The armature plate 23 has a stop plate 24 and a washer 25 on the flange surface 22a of the clutch hub 22.
At the same time, a leaf spring 2 whose one end is fixed with a rivet 26
By fixing the other end of 7 on the end face with a rivet 28, it is arranged to be able to move a certain distance in the axial direction.

With the above configuration, the rotor portion 12 of the electromagnetic clutch 11, which is rotatably supported on the sleeve 5 via the ball bearing 10, is driven by a V-belt pulled into the V-belt groove 121a. Perform a rotational movement.

When a voltage is applied to the excitation coil 16, magnetic flux forms a closed loop with the core 17, inner tube 122, armature plate 23, friction surface 123, armature plate 23, outer tube 121, and core 17 as shown by arrows in FIG. φ is generated, and a force that attracts the armature plate 23 in the direction of the friction surface 123 of the rotor portion 12 acts.

At this time, the armature plate 23 moves in the direction of the friction surface 123 against the reaction force of the leaf spring 27 and comes into contact with the friction surface 123. It is transmitted to the main shaft 3 via the clutch hub 22 and drives the compressor.

When the voltage application to the excitation coil 16 is stopped, the magnetic flux ψ forming the above-mentioned closed loop disappears, so the force that attracts the armature plate 23 disappears, and the armature plate 23 is pulled away from the friction surface 123 by the reaction force of the leaf spring 27. break away.

Therefore, the rotational motion transmission to the main shaft 3 is interrupted and the drive of the compressor is stopped.

Note that all the tension due to the V-belt stretched on the outer circumference of the rotor section 12 is applied to the sleeve 5, but by fixing the flange surface of the flange section 5b onto the outer end surface 2b of the front housing 2 with a plurality of bolts, etc., a large tension can be applied. can withstand.

Further, the inner race 10a of the ball bearing 10 that rotatably supports the rotor portion 12 is held between the flange portion 5b of the sleeve 5 and the snap ring 13, and is prevented from moving in the axial direction. Anti-rotation mechanism 14 formed between the end face and the end face of the inner race 10a
Relative movement with the sleeve 5 is prevented by.

Here, the rotation prevention mechanism 14 of the inner race 10a of the ball bearing 10 will be explained with reference to FIG. 5. An uneven portion 14a is formed on the end surface of the flange portion 5b of the sleeve 5, and is opposed to the end surface of the flange portion 5b. One or more pins 14b are disposed on the end surface of the inner race 10a of the ball bearing 10, and the pins 14b are locked in the recesses of the uneven portion 14a to prevent rotational movement of the inner race 10a.

In addition to the above-described structure, the rotation prevention mechanism 14 of the inner race 10a has a protrusion 141a formed on the end surface of the flange portion 5b, and a protrusion 141a on the end surface of the inner race 10a, as shown in FIGS. 6 to 8. The protrusion 141 of the flange portion 5b
A protrusion 141b having the same shape as a is formed, and both protrusions 141
a, 14lb, and an uneven portion 142b having a similar shape to the uneven portion 142a formed on the end surface of the flange portion 5b is formed on the inner race 10a,
A structure that prevents rotational movement by engaging both the uneven parts 142a and 142b, and furthermore, a pin insertion hole 143a is formed in the end face of the flange part 5b, and the inner race 10
Relative movement of the inner race 10b with respect to the sleeve 5 can also be easily prevented by forming a pin 143b on the end surface of the inner race 10b and inserting the pin 143b into the pin insertion hole 143a of the flange portion 5b.

As described above using the embodiments, the present invention provides a sleeve that includes the main shaft 3 protruding from the opening 2a of the front housing 2 on the outer end surface 2b of the front housing 2 made of aluminum alloy, and has a flange surface that expands in the radial direction. The sleeve 5 is fixed to the front housing 2 by arranging the sleeve 5 and fixing the flange surface to the outer end surface 2b, and the rotor part 12 is rotatably supported on the outside of the sleeve 5 via a ball bearing 10, Since all of the belt tension applied to the rotor section 12 is received by the sleeve 5, it can receive a large tension even if the front housing 2 is made of aluminum alloy, and the weight of the entire compressor can be reduced. .

In addition, since the sleeve 5 that supports the ball bearing 10 is formed separately from the front housing 2, the inner diameter of the ball bearing 10 can be reduced, so the structure of the electromagnetic clutch can be reduced while maintaining the same performance as the conventional one. As a result, the manufacturing cost of the electromagnetic clutch can be reduced, and the weight of the entire clutch can be reduced, and the rotation speed of the compressor can be increased by changing the transmission ratio with the external driving force due to the reduction in the outer diameter. This means that the machine will have a large cooling capacity.

Furthermore, the outer end surface 2b of the front housing 2 and the sleeve 5
Since the space between the main shaft 3 and the flange portion 5b is sealed by the sealing member 7 disposed on the outer end surface 2b, a sealing chamber 8 is formed between the main shaft 3 and the main shaft 3 in the cylindrical portion 5a of the sleeve 5 that encloses the main shaft 3. This makes it possible to improve the assembly and serviceability of the shaft seal mechanism 9.

Furthermore, the inner race 10a of the ball bearing 10 fitted onto the sleeve 5 and the flange portion 5b of the sleeve 5
Since the rotation prevention mechanism 14 of the inner race 10a is formed between the inner race 10a and the end face, the ball bearing 10 fitted onto the sleeve 5 can be loosely fitted, and as a result, the press-fitting structure can be simplified. Since the serviceability of the electromagnetic clutch can be improved and the rotation of the inner race 10a is stopped, the ball bearing 1
0 lifespan can be improved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional example of the electromagnetic clutch mounting structure for a compressor, Fig. 2 is a sectional view showing another conventional example of the electromagnetic clutch mounting structure, and Fig. 3 is a ball bearing inner race retention in Fig. 2. FIG. 4 is a sectional view showing an electromagnetic clutch mounting structure for a compressor according to an embodiment of the present invention. FIG. 5 is an explanatory diagram showing an embodiment of a ball bearing inner race rotation prevention mechanism. 6 to 8 are explanatory diagrams showing other embodiments of the rotation prevention mechanism. 2...Front housing, 3...Main shaft, 5...IJ-fu, 7...Seal member, 8...Seal chamber , 9... Shaft seal mechanism, 10... Ball bearing, 1
DESCRIPTION OF SYMBOLS 1... Electromagnetic clutch, 12... Rotor part, 14... Anti-rotation mechanism, 16...
Excitation coil, 17...core.

Claims (1)

[Scope of Claims] 1. In a configuration for supporting an electromagnetic clutch disposed on the outer periphery of the end of a main shaft that protrudes through the center of a front housing disposed at an end of a compressor main body, A cylindrical part that protrudes from its end face to enclose the main shaft and forms a seal chamber in which a shaft seal mechanism is disposed in the gap with the main shaft, and is fixed on the outer end face of the front housing, and the outer end face of the front housing is defined as the outer end face. A sleeve consisting of a flange portion sealed by a sealing member disposed between the sleeve is provided, and a ball bearing rotatably supporting the rotor portion of the electromagnetic clutch is mounted on the outer periphery of the cylindrical portion of the sleeve. A support structure for an electromagnetic clutch characterized by being held between the end face of the flange part and a snap ring disposed on the outside of the tip of the cylindrical part, and in which a rotation prevention mechanism is formed between the end face of the inner race of the ball bearing and the end face of the flange part. . 2. A protrusion concentric with the opening is formed on the outer periphery of the outer end surface of the opening of the front housing, a step is formed on the flange of the sleeve facing the protrusion, and the step is locked onto the protrusion. A support structure for an electromagnetic clutch according to claim 1, characterized in that: 3. A patent characterized in that an uneven portion is formed on the end surface of the flange portion, a pin is formed on the inner race end surface of the ball bearing, and the rotation prevention mechanism is configured by engaging the pin with the recessed portion of the uneven portion. A support structure for an electromagnetic clutch according to claim 1. 4. A rotation prevention mechanism is constructed by forming a protrusion on the end face of the flange portion, and forming a protrusion on the inner race end face of the ball bearing facing the protrusion, and engaging both protrusions. A support structure for an electromagnetic clutch according to claim 1. 5 An uneven part is formed on the end face of the flange part, and an uneven part of the same shape as this uneven part is formed on the inner race end face of the ball bearing facing the same, and by engaging both the uneven parts, a rotation prevention mechanism is created. A support structure for an electromagnetic clutch according to claim 1, characterized in that the support structure comprises: 6. A rotation prevention mechanism is constructed by forming a pin insertion hole in the end face of the flange portion, forming a pin in the inner race, and engaging the pin with the pin insertion hole in the flange portion. Support structure of the electromagnetic clutch described in scope 1.