BACKGROUND OF THE INVENTION
1. Field of the Invention
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The present invention relates to a configuration of a driving pulley and a belt at a motor that drives a rotary drum of a drum-type washing machine.
2. Background Art
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A conventional configuration for driving a rotary drum of a drum-type washing machine is disclosed in, for example, Japanese Patent Application Unexamined Publication No.
2009-78056 (hereinafter, referred to as "
Patent Literature 1"). In the configuration, rotation of a motor fixed to an outer bottom portion of a water tank is transmitted from a driving pulley formed on a motor shaft or a driving pulley fixed to a motor shaft to a driven pulley directly connected to the rotary drum via a belt.
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Hereinafter, the configuration of the conventional drum-type washing machine described in Patent Literature 1 is described with reference to FIG. 4. FIG. 4 is a longitudinal sectional view of the conventional drum-type washing machine.
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As shown in FIG. 4, the conventional drum-type washing machine has washing machine main body 31 including water tank 32. Water tank 32 includes rotary drum 33 that is axially supported by rotation shaft 35 rotatably forwardly or reversely. An outer peripheral wall of rotary drum 33 is provided with a large number of small holes 41 for extracting water during a dehydrating operation, and an inner peripheral wall of rotary drum 33 is provided with a plurality of baffles 36 for agitating laundry. Baffles 36 provided on rotary drum 33 agitate the laundry by low-speed forward or reverse rotation (for example, 50 rpm) during a washing process, and it extracts water from the laundry by centrifugation at a high-speed one-way rotation (for example, 1000 rpm) during a dehydrating process.
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Furthermore, rotation shaft 35 is fixed to the right end of rotary drum 33 shown in FIG. 4, and driven pulley 37 is fixed to the right end of rotation shaft 35. Motor 20 is provided on the outer bottom portion of water tank 32. A plurality of streams of V grooves 43 (which are described below with reference to FIG. 5) are formed on an end of motor shaft 39 of motor 20. Belt 38 having a plurality of streams of V-shaped grooves 42 (which are described below with reference to FIG. 5) is extended between motor shaft 39 and driven pulley 37 in motor 20.
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On the upper part of washing machine main body 31, controller 34 is provided. Controller 34 incorporates, for example, micro-computer (not shown) that receives an input signal from, for example, a switch (not shown). Controller 34 controls a series of processes including the washing process to the dehydrating process, and also carries out switching control of motor 20 between a low-speed rotation in the washing process and a high-speed rotation in the dehydrating process.
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Hereinafter, a configuration of the motor shaft of the motor and the belt in the conventional drum-type washing machine is described with reference to FIG. 5. FIG. 5 is an enlarged view of a principal part to illustrate a configuration of the vicinity (part B in FIG. 4) of the motor shaft of the motor of the conventional drum-type washing machine.
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As shown in FIG. 5, in the outer periphery in the vicinity of the tip part of motor shaft 39 formed of a steel material having strength and rigidity, a plurality of streams of V grooves 43 that engage with V-shaped grooves 42 of belt 38 are formed. At this time, V grooves 43 are formed in such a manner that outer diameter D2 of the streams of V grooves 43 of motor shaft 39 is substantially the same as (including identical to) diameter D1 of motor shaft 39. Therefore, it is not necessary to install a driving pulley by using another member on motor shaft 39, so that a pulley at the driving side can be achieved by motor shaft 39 having a smaller diameter. As a result, even if the outer diameter of driven pulley 37 is small, the speed reduction ratio (diameter of driven pulley 37 / diameter of motor shaft 39) of motor shaft 39 and driven pulley 37 can be increased.
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As described above, a conventional drum-type washing machine has a configuration in which the rotation of motor 20 is transmitted to rotary drum 33 via belt 38 at one speed reduction ratio by carrying out switching control of the number of rotations of motor 20. Thus, rotary drum 33 can be rotationally driven during the washing process and the dehydrating process.
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However, in the conventional configuration, in order to further increase the speed reduction ratio, the outer diameter of motor shaft 39 that is the driving pulley at the motor side is required to be further smaller. As a result, a circumferential velocity of belt 38 and V groove 43 of motor shaft 39 is further increased.
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In general, belt 38 is mainly formed of synthetic rubber having heat resistance, abrasion resistance, and the like. Belt 38 has a large frictional force. Therefore, V-shaped groove 42 of belt 38 and V groove 43 provided in the outer periphery in the vicinity of the tip part of motor shaft 39 adhere to and are separated from each other repeatedly at a high circumferential velocity. As a result, a sliding noise due to high speed adhesion and separation occurs, and the sound as an unusual noise gives an uncomfortable feeling to a user during a washing operation.
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Furthermore, when low-temperature washing water is supplied to water tank 32, water (water vapor) contained in the air inside washing machine main body 31 may be coagulated (dew condensation) on the outer wall of water tank 32 and the like, and may drop and adhere to a sliding part between V-shaped groove 42 of belt 38 and V groove 43 of motor shaft 39. At this time, when the circumferential velocity of V-shaped groove 42 of belt 38 and V groove 43 of motor shaft 39 is low, even if a small amount of water adheres to the sliding part, it does not have a large effect on the rotation transmission force to rotary drum 33. However, as in a conventional example, when the pulley at the driving side is a motor shaft, since the diameter of the motor shaft is small, the circumferential velocity becomes fast. As a result, slipping (slip) occurs between V-shaped groove 42 of belt 38 and V groove 43 of motor shaft 39. Therefore, the rotation of motor 20 cannot be transmitted exactly to rotary drum 33. As a result, the performance in the washing process and the dehydrating process may be deteriorated.
SUMMARY OF THE INVENTION
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A drum-type washing machine of the present invention has a configuration including a water tank supported in a washing machine main body, a rotary drum supported in the water tank, a motor fixed to an outer bottom portion of the water tank, a driving pulley provided on one end of a motor shaft of the motor, a rotation shaft having one end fixed to the rotary drum, a driven pulley securely installed on the other end of the rotation shaft, and a belt that transmits rotation of the motor to the driven pulley. In the configuration, a waterproof cover covering around the driving pulley is fixed to the motor.
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Thus, the dispersion of an unusual noise occurring due to the sliding friction between the driving pulley and the belt can be prevented. Furthermore, "slipping" can be prevented from occurring due to water attached to a sliding part between the driving pulley and the belt. As a result, it is possible to prevent the deterioration of washing performance due to the change of the number of rotations of the rotary drum in a washing process and a dehydrating process.
BRIEF DESCRIPTION OF DRAWINGS
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- FIG. 1 is a longitudinal sectional view showing a drum-type washing machine in accordance with an exemplary embodiment of the present invention.
- FIG. 2 is an enlarged view of a principal part to illustrate a configuration of the vicinity (part A in FIG. 1) of a motor shaft of a motor of the drum-type washing machine.
- FIG. 3 is a sectional view taken on line 3-3 of the drum-type washing machine from the direction B shown in FIG. 2.
- FIG. 4 is a longitudinal sectional view showing a conventional drum-type washing machine.
- FIG. 5 is an enlarged view of a principal part to illustrate a configuration of the vicinity (part B in FIG. 4) of a motor shaft of a motor of the conventional drum-type washing machine.
DETAILED DESCRIPTION OF THE INVENTION
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Hereinafter, an exemplary embodiment of the present invention is described with reference to drawings. The same reference numerals are given to the same configurations as in the conventional example and the description thereof is omitted herein. Furthermore, the following exemplary embodiment does not limit the present invention.
EXEMPLARY EMBODIMENT
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FIG. 1 is a longitudinal sectional view showing a drum-type washing machine in accordance with an exemplary embodiment of the present invention.
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As shown in FIG. 1, a drum-type washing machine according to this exemplary embodiment has washing machine main body 31 including water tank 32. Water tank 32 includes rotary drum 33 that is axially supported by rotation shaft 35 rotatably forwardly or reversely. An outer peripheral wall of rotary drum 33 is provided with a large number of small holes 41 for extracting water during a dehydrating operation, and an inner peripheral wall of rotary drum 33 is provided with a plurality of baffles 36 for agitating laundry. Baffles 36 provided on rotary drum 33 agitate laundry by low-speed forward or reverse rotation (for example, 50 rpm) during a washing process, and it extracts water from the laundry by centrifugation at a high-speed one-way rotation (for example, 1000 rpm) during a dehydrating process.
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Rotary drum 33 is rotationally driven via motor 20 provided on the outer bottom portion of water tank 32 by the below-mentioned mechanism. At this time, at the tip part of a motor shaft (not shown in FIG. 1) of motor 20, waterproof cover 1 is placed.
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Hereinafter, a configuration and a mechanism in the vicinity of the motor shaft of the motor of the drum-type washing machine of this exemplary embodiment are described with reference to FIGS. 2 and 3.
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FIG. 2 is an enlarged view of a principal part to illustrate a configuration of the vicinity (part A in FIG. 1) of the motor shaft of the motor of the drum-type washing machine. FIG. 3 is a sectional view taken on line 3-3 of the drum-type washing machine from the direction B shown in FIG. 2.
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As shown in FIG. 2, in the drum-type washing machine of this exemplary embodiment, at a tip part of motor shaft 39 of motor 20, driving pulley 2 having a large number of V grooves 43 to which belt 38 is extended is fixed. On the outer periphery of driving pulley 2 fixed to motor shaft 39, waterproof cover 1 that covers around driving pulley 2 is provided. Waterproof cover 1 is formed of, for example, a plastic molding member, and in, for example, a cylindrical shape having a substantially rectangular U-shaped (including rectangular U-shaped) section and having openings 3 in positions through which belt 38 passes.
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Waterproof cover 1 has a plurality of hooks 4 having, for example, an L-shape at motor 20 side. Hook 4 is attached to be engaged with small hole 8 of front plate 5 of motor 20, whereby waterproof cover 1 and the motor are positioned. Furthermore, at the motor 20 side of the outer periphery of cylinder part 1a of waterproof cover 1, a plurality of mounting seats 6 are formed integrally with cylinder part 1a, and screwed to front plate 5 of motor 20 with, for example, machine screw 7.
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In the inner periphery of cylinder part 1a of waterproof cover 1, noise-absorbing material 9 such as felt made of, for example, non-woven fabric, foam, and a porous material is placed by fitting, or adhesive bonding.
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At the right side of the rectangular U-shape (right surface side shown in FIG. 2) of waterproof cover 1, side surface opening 10 linking to opening 3 to allow belt 38 to pass through is provided. Through side surface opening 10 provided in waterproof cover 1, belt 38 can be placed onto driving pulley 2 fixed to motor shaft 39, a sliding state between V-shaped groove 42 of belt 38 and V groove 43 of driving pulley 2 can be observed, and sag due to the change in tension of belt 38 can be observed.
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As shown in FIG. 3, on the upper part of waterproof cover 1, opening 3 to allow belt 38 to pass through is provided in two places. Consequently, noise-absorbing material 9 is placed on all over the inner peripheral surface of cylinder part 1a of waterproof cover 1 except for of two openings 3.
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On the upper side surface of openings 3, which allow belt 38 to pass through, of waterproof cover 1, rib body 11 is integrally provided in the same direction as the extending direction of motor shaft 39. This can prevent water, which is condensed (dew condensation) on the water tank and the like and which drops on upper surface 12 of waterproof cover 1, from entering a sliding part between V-shaped groove 42 of belt 38 and V groove 43 of driving pulley 2 inside waterproof cover 1 from opening 3.
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As mentioned above, according to the drum-type washing machine of this exemplary embodiment, an unusual noise such as a sliding noise occurring in the sliding part between belt 38 and driving pulley 2 by the rotation of motor 20 can be cut off (shielded) by waterproof cover 1. This makes it possible to remarkably reduce an unusual noise such as a sliding noise that propagates to the outside of washing machine main body 31. As a result, it is possible to suppress an uncomfortable feeling to a user due to an unusual noise during an operation of the washing machine.
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According to a drum-type washing machine of this exemplary embodiment, by placing noise-absorbing material 9 on the inner periphery of waterproof cover 1, an unusual noise such as a sliding noise can be absorbed, or generation of acoustic echo in waterproof cover 1 can be prevented. As a result, propagation of the unusual noise to the outside of washing machine main body 31 can be remarkably reduced.
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According to the drum-type washing machine of this exemplary embodiment, by placing noise-absorbing material 9 all over the inner periphery of waterproof cover 1 except for openings 3 to allow belt 38 to pass through, an unusual noise such as a sliding noise can be effectively absorbed, and occurrence of acoustic echo and the like can be remarkably suppressed.
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According to the drum-type washing machine of this exemplary embodiment, the periphery of the sliding part between V-shaped groove 42 of belt 38 and V groove 43 of driving pulley 2, except for openings 3, is covered with waterproof cover 1. Therefore, it is possible to effectively reduce the entering of water, which is condensed (dew condensation) and drops on the outer wall of water tank 32 and the like, into the sliding part. This makes it possible to prevent the occurrence of "slipping" between V-shaped groove 42 of belt 38 and V groove 43 of driving pulley 2. As a result, it is possible to prevent the deterioration of washing performance due to the change of the number of rotations of rotary drum 33 in the washing process and the dehydrating process.
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The present invention has a configuration including a water tank supported in a washing machine main body, a rotary drum supported in the water tank, a motor fixed to an outer bottom portion of the water tank, a driving pulley provided on one end of a motor shaft of the motor, a rotation shaft having one end fixed to the rotary drum, a driven pulley securely installed on the other end of the rotation shaft, and a belt that transmits rotation of the motor to the driven pulley. In the configuration, a waterproof cover covering around the driving pulley is fixed to the motor. This makes it possible to prevent an unusual noise occurring due to the sliding friction between the driving pulley and the belt from dispersing to the outside, and to prevent the occurrence of "slipping" due to water attached to a sliding part between the driving pulley and the belt.
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Furthermore, the present invention has a configuration in which the waterproof cover is provided a noise-absorbing material is placed on an inner periphery thereof. This makes it possible to effectively absorb an unusual noise occurring due to the sliding friction between the driving pulley and the belt and to remarkably reduce the dispersion of the noises to the outside.
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Furthermore, the present invention has a configuration in which the noise-absorbing material is placed around the driving pulley except for an opening for the belt to pass through. This makes it possible to effectively absorb an unusual noise occurring due to the sliding friction between the driving pulley and the belt.
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Furthermore, in the present invention, the noise-absorbing material includes felt. Thus, it is possible to achieve high absorbing efficiency with respect to an unusual noise occurring due to the sliding friction between the driving pulley and the belt.
