Washing machine

Abstract

The present invention provides a cleaning machine that can suppress wear on the shaft head even if abrasive material gets between the bearing and the shaft during cleaning. [Solution] The dishwasher 1 comprises a nozzle 11 (12) and a support part 13 (14). The nozzle is equipped with a detachable mechanism 37 (47), and the support part comprises a shaft 130 (140) and a bearing 135 (145). The detachable mechanism has a pair of engaging parts 37d, 37e (47d, 47e). The bearing has a first bearing that rotatably mounts the pair of engaging parts to the shaft. The shaft has a first shaft having a head part 131A (141A) that functions as a retainer for the first bearing to come off the shaft in the axial direction, and a body part 131B (141B) that rotatably supports the first bearing. At least the opposing surface of the first bearing facing the head part of the first shaft is formed of PEEK.

Description

Technical Field

[0001] The present invention relates to a washing machine.

Background Art

[0002] Patent Document 1 discloses a washing machine including a nozzle provided in a washing chamber for accommodating an object to be washed, the nozzle spraying water into the washing chamber while rotating in one direction, and a support portion provided in the washing chamber for rotatably supporting the nozzle. The nozzle has a detaching mechanism for detaching the nozzle from the support portion. The support portion has a shaft and a bearing rotatably attached to the shaft. The detaching mechanism attaches or detaches the nozzle to or from the support portion by engaging or disengaging with the bearing of the support portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional washing machine described above, as shown in Figure 11, pressing the pair of knobs 100a, 100a of the attachment / detachment mechanism 100 presses the first fitting part 100b and the second fitting part 100c, causing the first fitting part 100b and the second fitting part 100c to separate from each other. This releases the fitting between the attachment / detachment mechanism 100 and the support part 110, allowing the nozzle 120 to be removed from the support part 110. Furthermore, releasing the pressure on the pair of knobs 100a, 100a of the attachment / detachment mechanism 100 causes the first fitting part 100b and the second fitting part 100c to be pressed and move due to the compression of the first compression spring 100d and the second compression spring 100e when the pair of knobs 100a, 100a was pressed, causing the first fitting part 100b and the second fitting part 100c to come into contact with each other. At this time, the circular fitting portion formed by the opposing portions of the first fitting portion 100b and the second fitting portion 100c fits into the recess 111A of the bearing 111 of the support portion 110, as shown in Figure 12. As a result, the fitting of the support portion 110 by the attachment / detachment mechanism 100 is restored, and the nozzle 120 can be fixed to the support portion 110.

[0005] When cleaning water is sprayed from the cleaning spray holes formed in the nozzle 120, the nozzle 120 rotates, and the bearing 111, which is attached to the nozzle 120 via the first fitting portion 100b and the second fitting portion 100c, also rotates integrally. At this time, the bearing 111 slides against the shaft 112 of the support portion 110. More specifically, the bearing 111 slides against the body portion 112A of the shaft 112 that rotatably supports the bearing 111, and against the head portion 112A of the shaft 112 that functions as a retainer for the bearing 111.

[0006] Conventionally, the shaft 112 and bearing 111 are designed with sliding properties and wear resistance in mind, as they slide against each other. For example, the bearing 111 is made of polyphenylene sulfide resin (PPS resin) considering durability and sliding properties, while the shaft 112 is made of stainless steel to suppress wear and to ensure that wear mainly occurs on the bearing 111 side (in other words, so that only the bearing 111 needs to be replaced). However, in washing machines operating in physical stores, wear sometimes occurs on the shaft 112 side, more specifically on the sliding surface P2 of the head portion 112A of the shaft 112, rather than on the bearing 111 side. When such wear occurs on the head portion 112A of the shaft 112, there is a risk that the nozzle 120 will become loose.

[0007] The inventors of this invention, after diligent study, discovered a mechanism for wear occurring on the shaft 112 side rather than the bearing 111 side. First, by observing many washing machines operating in actual stores, the inventors found that the outer surface of the shaft 112 was not worn uniformly, but rather in a groove-like pattern. They then found that this groove-like wear was caused by abrasives (such as iron powder) contained in scrubbing brushes used to remove stubborn dirt. In other words, when pre-washing dirty dishes, scrubbing brushes are used to remove stubborn dirt, and the abrasives contained in these brushes mix into the washing water. The inventors discovered that abrasives are relatively hard substances and flow between the bearing 111 and the shaft 112 during washing. Furthermore, the inventors discovered that not only does this abrasive material simply flow between the bearing 111 and the shaft 112, but in particular, the abrasive material is embedded in the sliding surface of the bearing 111 that faces the head portion 112A of the shaft 112.

[0008] As a result of further diligent investigation by the inventors of the present invention, they have found that the reason why the abrasive material gets embedded in the sliding surface of the bearing 111 facing the head portion 112A of the shaft 112 is that when the nozzle 120 rotates, the bearing 111, which rotates integrally with the nozzle 120, applies a strong force toward the shaft 112, in particular the head portion 112A, which functions as a retainer for the bearing 111. In other words, pressurized sliding occurs between the head portion 112A of the shaft 112 and the bearing 111. The inventors of the present invention have found that the abrasive material is more likely to get embedded in such a pressurized sliding surface, that is, in the case of the bearing 111, on the sliding surface P2 of the head portion 112A of the shaft 112.

[0009] Furthermore, when abrasive material becomes embedded in the sliding surface P2 of the head portion 112A of the shaft 112 in the bearing 111, ternary wear occurs. As shown in Figure 13(A), normally, when a foreign object F with high hardness comes into contact with a bearing 111 made of PPS resin, which has a lower hardness than the foreign object F, the contact surface of the bearing 111 with the foreign object F is cut and wear occurs. This type of wear is called binary wear. On the other hand, as shown in Figure 13(B), ternary wear (ternary abrasive wear) occurs when hard particles are interposed between two opposing surfaces. Ternary abrasive wear is a phenomenon in which hard solid particles (sand grains or wear grains, etc.) are present between two opposing surfaces, causing the hard particles to embed themselves in the opposing surface with lower hardness. First, the opposing surface with lower hardness wears down, and the hard particles embedded in the opposing surface with lower hardness then shave off the surface with higher hardness.

[0010] Therefore, the object of the present invention is to provide a cleaning machine that can suppress wear on the head portion of the shaft even if an abrasive gets between the bearing and the shaft during cleaning. [Means for solving the problem]

[0011] (1) The washing machine according to the present invention comprises a washing chamber containing an object to be washed and a nozzle that sprays water into the washing chamber while rotating in one direction, and a support part provided in the washing chamber that rotatably supports the nozzle, wherein the nozzle is provided with a detachment mechanism for attaching and detaching the nozzle to and from the support part, the support part comprises a first shaft and a first bearing rotatably attached to the first shaft, the detachment mechanism has a pair of engaging parts that engage with the first bearing by clamping the first bearing in a direction perpendicular to the rotation axis of the first bearing, the first shaft has a head part that functions as a retainer for the first bearing to come off the first shaft in the axial direction, and a body part that rotatably supports the first bearing, and at least the opposing surface of the first bearing facing the head part of the first shaft is formed of aromatic polyether ketone.

[0012] In this cleaning machine configuration, at least the opposing surface of the first bearing that faces the head portion of the first shaft is formed of an aromatic polyether ketone having a hardness equivalent to that of the abrasive. This prevents the abrasive from becoming embedded in the opposing surface of the first bearing that faces the head portion of the first shaft, and allows the abrasive to flow out from between the bearing and the shaft along with the cleaning water. As a result, even if the abrasive gets between the bearing and the shaft during cleaning, wear on the head portion of the shaft can be suppressed.

[0013] (2) In the washing machine described in (1) above, the first shaft may be made of stainless steel. In this configuration, even if an abrasive gets between the bearing made of aromatic polyether ketone and the shaft made of stainless steel during washing, wear of the head portion of the shaft can be suppressed.

[0014] (3) In the washing machine described in (1) or (2) above, the first bearing may be made of aromatic polyether ketone. This configuration makes it easy to provide a component that serves as the first bearing.

[0015] (4) In any one of the washing machines described in (1) to (3) above, the support part further comprises a second shaft connected to the first shaft in the direction of extension of the first shaft, and the nozzle is fitted with a second bearing that is rotatably mounted relative to the second shaft, and at least the opposing surface of the second bearing that faces the second shaft may be made of ultra-high molecular weight polyethylene. In this configuration, at least the opposing surface of the second bearing that faces the second shaft is made of ultra-high molecular weight polyethylene, which has a lower hardness than aromatic polyether ketone. This prevents the gap between the second shaft and the second bearing from increasing due to wear of the sliding surface of the second shaft with the second bearing. As a result, the possibility of water flowing through the washing channel flowing back into the rinsing channel can be reduced.

[0016] (5) The washing machine according to the present invention comprises a nozzle provided in a washing chamber for containing an object to be washed, which sprays water into the washing chamber while rotating in one direction; a support provided in the washing chamber which rotatably supports the nozzle; a washing channel for supplying washing water to the spray hole of the nozzle; and a rinsing channel for supplying rinsing water to the spray hole of the nozzle, wherein the support has a second shaft having a rinsing channel extending axially inside, and a second bearing is attached to the nozzle so as to be rotatable with respect to the second shaft, the second bearing is located inside the washing channel which is located outside the second shaft, and at least the opposing surface of the second bearing that faces the second shaft is formed of ultra-high molecular weight polyethylene.

[0017] In this cleaning machine configuration, at least the opposing surface of the second bearing that faces the second shaft is made of ultra-high molecular weight polyethylene, which has a lower hardness than aromatic polyether ketone. This suppresses the widening of the gap between the second shaft and the second bearing due to wear on the sliding surface of the second shaft against the second bearing. As a result, the possibility of water flowing through the cleaning channel flowing back into the rinsing channel can be reduced. [Effects of the Invention]

[0018] According to the present invention, even if an abrasive enters between the bearing and the shaft during cleaning, wear of the head portion of the shaft can be suppressed.

Brief Description of the Drawings

[0019] [Figure 1] FIG. 1 is a perspective view of a dishwasher according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a schematic configuration of the dishwasher. [Figure 3] FIG. 3 is a view showing a cross-sectional configuration of a part of the upper nozzle (lower nozzle) and the upper support portion (lower support portion). [Figure 4] FIG. 4 is a perspective view showing a cross-sectional configuration of a part of the upper nozzle (lower nozzle) and the upper support portion (lower support portion). [Figure 5] FIG. 5 is a perspective view of the upper nozzle. [Figure 6] FIG. 6(a) is a perspective view showing the state of the attachment / detachment mechanism when fixed, and FIG. 6(b) is a perspective view showing the state of the attachment / detachment mechanism when released. [Figure 7] FIG. 7 is a perspective view of the lower nozzle. [Figure 8] FIGS. 8(A) and 8(B) are diagrams for explaining the operation and effect of the first bearing according to the present embodiment. [Figure 9] FIG. 9 is a diagram for explaining the problem of a conventional second bearing. [Figure 10] FIG. 10 is a diagram for explaining the operation and effect of the second bearing according to the present embodiment. [Figure 11] FIG. 11 is a perspective view showing a cross-sectional configuration of a part of the upper nozzle (lower nozzle) and the upper support portion (lower support portion) in a conventional dishwasher. [Figure 12] FIG. 12 is a diagram schematically showing the upper nozzle (lower nozzle) and the upper support portion (lower support portion) in a conventional dishwasher. [Figure 13]Figure 13(A) is a diagram illustrating the mechanism of binary wear. Figure 13(B) is a diagram illustrating the mechanism of ternary wear. [Modes for carrying out the invention]

[0020] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant descriptions are omitted. The dimensional ratios in the drawings do not necessarily match those in the description. In the following description, for the sake of clarity, the directions (up and down direction, front and back direction, left and right direction) as defined in Figure 1 will be defined.

[0021] Figure 1 is a perspective view of a dishwasher according to one embodiment. Figure 2 is a cross-sectional view showing the schematic configuration of the dishwasher. As shown in Figures 1 and 2, the dishwasher (washer) 1 has a washing machine body 2 covered with stainless steel panels. The washing machine body 2 is divided into an upper part 2A in which a washing chamber 3 is formed and a lower part 2B in which a machine room 4 is formed. At the corner on the rear side of the washing machine body 2, a support column 6 is arranged that extends vertically across the upper part 2A and the lower part 2B, and a rear panel 5 is arranged between the support columns 6, 6.

[0022] The upper part 2A of the washing machine body 2 is provided with a box-shaped door 7 for opening and closing the washing chamber 3. This door 7 is guided to move up and down freely by a pair of stainless steel support columns 6, 6 and is also moved up and down by a handle 8A that extends horizontally at the front.

[0023] The ends of a pair of left and right rotating arms 8B, 8B are fixed to both ends of the handle 8A, and the rotating arms 8B, 8B are positioned diagonally along the side 7A of the door 7. One end of a link section 8C, which is positioned along the side 7A of the door 7, is rotatably connected to the rotating arms 8B, 8B, and the other end of the link section 8C is connected to the door 7 via an axle pin 8D, so that the door 7 can move up and down in response to the rotational movement of the handle 8A. Legs 9 are attached to the four corners of the bottom surface of the washing machine body 2.

[0024] As shown in Figure 2, a rack rail 10 is detachably arranged inside the washing chamber 3, and a grid-like dish rack on which dishes such as plates and bowls (items to be washed) are arranged is placed on this rack rail 10. An upper nozzle (nozzle) 11 is located at the top of the washing chamber 3. A lower nozzle (nozzle) 12 is located at the bottom of the washing chamber 3.

[0025] The upper nozzle 11 is located above the washing chamber 3. The upper nozzle 11 is rotatably mounted on the upper (support) support 13 located above the washing chamber 3. Figure 3 is a diagram showing a partial cross-sectional configuration of the upper nozzle 11 (lower nozzle 12) and the upper support 13 (lower support 14). Figure 4 is a perspective view showing a partial cross-sectional configuration of the upper nozzle (lower nozzle) and the upper support 13 (lower support). As shown in Figures 3 and 4, the upper support 13 has a shaft 130 and a bearing 135. The shaft 130 is inserted into the first rinse water discharge pipe 22A (see Figure 5). The shaft 130 is composed of a first shaft 131 and a second shaft 132.

[0026] The first shaft 131 has a head portion 131A and a body portion 131B. The head portion 131A functions as a retainer for the first bearing 136 to axially dislodge from the shaft 130. The body portion 131B is the portion of the shaft 130 that extends axially (up and down). The body portion 131B rotatably supports the first bearing 136, which will be described in detail later. The first shaft 131 is made of stainless steel.

[0027] The second shaft 132 is connected to one end of the first shaft 131 in the direction of extension and is integrally formed with the first shaft 131. The second shaft 132 extends in the axial direction (vertical direction) of the shaft 130. The second bearing 137 and the second bearing 138, which will be described later, are rotatably positioned on the second shaft 132. The second shaft 132 is made of stainless steel. A portion of the second shaft 132 is connected to the first rinse water discharge pipe 22A and also functions as a supply pipe that supplies rinse water to the rinse passage 34 of the upper nozzle 11.

[0028] The bearing 135 is externally fitted onto the shaft 130 and is rotatably mounted relative to the shaft 130. The bearing 135 includes a first bearing 136, a second bearing 137, and a third bearing 138.

[0029] The first bearing 136 is rotatably mounted on the body portion 131B of the first shaft 131. The first bearing 136 rotates while sliding on the outer circumferential surface of the body portion 131B of the first shaft 131. The attachment / detachment mechanism 37 for the upper nozzle 11, which will be described in detail later, is connected to the first bearing 136. More specifically, the first engaging portion 37d and the second engaging portion 37e (a pair of engaging portions), which will be described in detail later, are attached to the recess 136A of the first bearing 136. As a result, the main body portion 30 of the upper nozzle 11 is connected to the first bearing 136 via the attachment / detachment mechanism 37.

[0030] At least the opposing surface of the first bearing 136 that faces the head portion 131A of the first shaft 131 is formed of aromatic polyether ketone (PEEK resin). PEEK resin is a type of thermoplastic super engineering plastic. In this embodiment, not only the opposing surface of the first bearing 136 that faces the head portion 131A of the first shaft 131, but the entire first bearing 136 is formed of PEEK resin.

[0031] The second bearing 137 is attached to the upper nozzle 11, allowing the upper nozzle 11 to rotate freely relative to the second shaft 132. The second bearing 137 rotates while sliding on the outer circumferential surface of the second shaft 132. The second bearing 137 is press-fitted into the opening of the upper nozzle 11 (i.e., the part into which the second shaft 132 is inserted and which faces the outer circumferential surface of the second shaft 132) and is fixed to the upper nozzle 11 by hooking its claws (end projections protruding radially outward from the second bearing 137 in Figure 3) onto the inside of the opening of the upper nozzle 11. The second bearing 137 is positioned on the side to which the first shaft 131 is connected in the extending direction of the second shaft 132. The second bearing 137 rotates while sliding on the outer circumferential surface of the portion of the second shaft 132 to which the inner pipe for supplying rinsing water to the rinsing passage 34 is not formed. The main body 30 of the upper nozzle 11 is connected to the second bearing 137.

[0032] At least the opposing surface of the second bearing 137 that faces the second shaft 132 is formed of ultra-high molecular weight polyethylene (UHMW-PE resin). UHMW-PE resin is a type of thermoplastic super engineering plastic. UHMW-PE resin has lower hardness and higher sliding properties than PEEK resin. In this embodiment, not only the opposing surface of the second bearing 137 that faces the second shaft 132, but the entire second bearing 137 is formed of UHMW-PE resin.

[0033] The second bearing 138 is attached to the upper nozzle 11, allowing the upper nozzle 11 to rotate freely relative to the second shaft 132. The second bearing 138 rotates while sliding on the outer circumferential surface of the second shaft 132. The second bearing 138 is press-fitted into the opening of the upper nozzle 11 (i.e., the part into which the second shaft 132 is inserted and the part facing the outer circumferential surface of the second shaft 132) and is fixed to the upper nozzle 11 by hooking its claws (end projections protruding radially outward from the second bearing 138 in Figure 3) onto the inside of the opening of the upper nozzle 11. The second bearing 138 is located on the side opposite to the side to which the first shaft 131 is connected in the extending direction of the second shaft 132. The second bearing 138 rotates while sliding on the outer circumferential surface of the portion of the second shaft 132 in which the inner pipe that supplies rinsing water to the rinsing passage 34 is formed. The second bearing 138 is located inside the washing passage 32. The second bearing 138 also serves as the partition between the washing channel 32 and the rinsing channel 34. The main body 30 of the upper nozzle 11 is connected to the second bearing 138.

[0034] At least the opposing surface of the second bearing 138 that faces the second shaft 132 is formed of the UHMW-PE resin described above. In this embodiment, not only the opposing surface of the second bearing 138 that faces the second shaft 132, but the entire second bearing 138 is formed of UHMW-PE resin.

[0035] Figure 5 is a perspective view of the upper nozzle 11. As shown in Figure 5, the upper nozzle 11 has a main body 30 that extends radially from the base end, which is the rotation center of the rotation axis of the upper nozzle 11, to the tip. The main body 30 integrally includes a cleaning spray hole 31 for spraying cleaning water stored in the cleaning water tank 15, a cleaning channel 32 (see Figure 4) that extends from the rotation center to the cleaning spray hole 31 and through which cleaning water flows, a rinsing spray hole 33 for spraying rinsing water stored in the rinsing water tank 19, and a rinsing channel 34 (see Figure 4) that extends from the rotation center to the rinsing spray hole 33 and through which rinsing water flows. The upper nozzle 11 rotates in one direction when the flow of cleaning water generated in the cleaning channel 32 or the flow of rinsing water generated in the rinsing channel 34 is converted into rotational force. The upper nozzle 11 is connected to a first wash water discharge pipe 18A that supplies wash water to the wash channel 32 and a first rinse water discharge pipe 22A that supplies rinse water to the rinse channel 34.

[0036] The upper nozzle 11 is equipped with a detachment mechanism 37 for attaching and detaching the main body 30 from the upper support portion 13 provided in the washing chamber 3. The detachment mechanism 37 has a pair of knobs 37a, 37a. The pair of knobs 37a, 37a protrude from the outer shape of the main body 30 along the operating direction D. The detachment mechanism 37 can attach and detach the main body 30 from the upper support portion 13 by pressing both of the pair of knobs 37a, 37a toward each other along the operating direction D.

[0037] Figure 6(a) is a perspective view showing the state of the attachment / detachment mechanism 37(47) when it is fixed. Figure 6(b) is a perspective view showing the state of the attachment / detachment mechanism 37(47) when it is released. As shown in Figures 6(a) and 6(b), the attachment / detachment mechanism 37 comprises a pair of knobs 37a, 37a, a first rail portion 37b connected to one of the knobs 37a, a first engaging portion 37d slidably provided within the first rail portion 37b and attached to one of the knobs 37a via a first compression spring 37f, a second rail portion 37c connected to the other knob 37a, a second engaging portion 37e slidably provided within the second rail portion 37c and attached to the other knob 37a via a second compression spring 37g, a first pressing portion 37h connected to one of the knobs 37a, and a second pressing portion 37i connected to the other knob 37a.

[0038] In a detachable mechanism 37 with this configuration, pressing the pair of knobs 37a, 37a along the operating direction D causes the second engaging portion 37e to be pressed via the first pressing portion 37h and the first engaging portion 37d to be pressed via the second pressing portion 37i, as shown in Figure 6(b). As a result, the first engaging portion 37d and the second engaging portion 37e separate from each other. This releases the engagement between the detachable mechanism 37 and the upper support portion 13, allowing the upper nozzle 11 (main body portion 30) to be removed from the upper support portion 13.

[0039] Furthermore, when the pressure on the pair of knobs 37a, 37a is released, as shown in Figure 6(a), the first compression spring 37f and the second compression spring 37g, which were compressed when the pair of knobs 37a, 37a were pressed, press and move the first engaging portion 37d and the second engaging portion 37e, causing the first engaging portion 37d and the second engaging portion 37e to come into contact with each other. At this time, the engaging portions formed by the opposing parts of the first engaging portion 37d and the second engaging portion 37e fit into the recess 136A of the first bearing 136 of the upper support portion 13 (see Figure 3). As a result, the engagement of the attachment / detachment mechanism 37 with the upper support portion 13 is restored, and the upper nozzle 11 (main body portion 30) can be fixed to the upper support portion 13.

[0040] As shown in Figure 2, the lower nozzle 12 is located below the washing chamber 3. The lower nozzle 12 is rotatably mounted on a lower support (support) 14 located below the washing chamber 3. As shown in Figures 3 and 4, the lower support 14 has a shaft 140 and a bearing 145. The shaft 140 is inserted into the second rinse water discharge pipe 22B (see Figure 5). The shaft 140 is composed of a first shaft 141 and a second shaft 142.

[0041] The first shaft 141 has a head portion 141A and a body portion 141B. The head portion 141A is the part that prevents the first bearing 146 from coming off the shaft 140 in the axial direction. The body portion 141B is the part that extends axially (up and down) along the shaft 140. The body portion 141B rotatably supports the first bearing 146, which will be described in detail later. The first shaft 141 is made of stainless steel.

[0042] The second shaft 142 is connected to one end of the first shaft 141 in the direction of extension and is integrally formed with the first shaft 141. The second shaft 142 extends in the axial direction (vertical direction) of the shaft 140. The second bearing 147 and the second bearing 148, which will be described later, are rotatably positioned on the second shaft 142. The second shaft 142 is made of stainless steel. A second rinse water discharge pipe 22B is connected to a portion of the second shaft 142, and it also functions as a supply pipe that supplies rinse water to the rinse passage 34 of the upper nozzle 11.

[0043] The bearing 145 is externally mounted on the shaft 140 and is rotatably mounted relative to the shaft 140. The bearing 145 includes a first bearing 146, a second bearing 147, and a third bearing 148.

[0044] The first bearing 146 is rotatably mounted on the body portion 141B of the first shaft 141. The first bearing 146 rotates while sliding on the outer circumferential surface of the body portion 141B of the first shaft 141. The attachment / detachment mechanism 47 of the lower nozzle 12 is connected to the first bearing 146. More specifically, the first engaging portion 47d and the second engaging portion 47e (a pair of engaging portions), which will be described in detail later, are attached to the recess 146A of the first bearing 146. As a result, the main body portion 40 of the lower nozzle 12 is connected to the first bearing 146 via the attachment / detachment mechanism 47.

[0045] At least the opposing surface of the first bearing 146 that faces the head portion 141A of the first shaft 141 is formed of PEEK resin. PEEK resin is a type of thermoplastic super engineering plastic. In this embodiment, not only the opposing surface of the first bearing 146 that faces the head portion 141A of the first shaft 141, but the entire first bearing 146 is formed of PEEK resin.

[0046] The second bearing 147 is attached to the lower nozzle 12, allowing the lower nozzle 12 to rotate freely relative to the second shaft 142. The second bearing 147 rotates while sliding on the outer circumferential surface of the second shaft 142. The second bearing 147 is press-fitted into the opening of the lower nozzle 12 (i.e., the part into which the second shaft 142 is inserted and the part facing the outer circumferential surface of the second shaft 142) and is fixed to the lower nozzle 12 by hooking its claws (end projections protruding radially outward from the second bearing 147 in Figure 3) onto the inside of the opening of the lower nozzle 12. The second bearing 147 is positioned on the side to which the first shaft 141 is connected in the extending direction of the second shaft 142. The second bearing 147 rotates while sliding on the outer circumferential surface of the portion of the second shaft 142 to which the inner pipe for supplying rinsing water to the rinsing passage 34 is not formed. The main body 40 of the lower nozzle 12 is connected to the second bearing 147.

[0047] At least the opposing surface of the second bearing 147 that faces the second shaft 142 is formed of UHMW-PE resin. UHMW-PE resin is a type of thermoplastic super engineering plastic. UHMW-PE resin is a material that has lower hardness and higher sliding properties than PEEK resin. In this embodiment, not only the opposing surface of the second bearing 147 that faces the second shaft 142, but the entire second bearing 147 is formed of UHMW-PE resin.

[0048] The second bearing 148 is attached to the lower nozzle 12, allowing the lower nozzle 12 to rotate freely relative to the second shaft 142. The second bearing 148 rotates while sliding on the outer circumferential surface of the second shaft 142. The second bearing 148 is press-fitted into the opening of the lower nozzle 12 (i.e., the part into which the second shaft 142 is inserted, and the part facing the outer circumferential surface of the second shaft 142) and is fixed to the lower nozzle 12 by hooking its claws (end projections protruding radially outward from the second bearing 148 in Figure 3) onto the inside of the opening of the lower nozzle 12. The second bearing 148 is positioned on the side opposite to the side to which the first shaft 141 is connected in the extending direction of the second shaft 142. The second bearing 148 rotates while sliding on the outer circumferential surface of the portion of the second shaft 142 in which the inner pipe that supplies rinsing water to the rinsing passage 44 is formed. The second bearing 148 is positioned inside the washing passage 42. The second bearing 148 also serves as the partition between the washing channel 42 and the rinsing channel 44. The main body 40 of the lower nozzle 12 is connected to the second bearing 148.

[0049] At least the opposing surface of the second bearing 148 that faces the second shaft 142 is formed of the UHMW-PE resin described above. In this embodiment, not only the opposing surface of the second bearing 148 that faces the second shaft 142, but the entire second bearing 148 is formed of UHMW-PE resin.

[0050] Figure 7 is a perspective view of the lower nozzle 12. As shown in Figure 7, the lower nozzle 12 has a main body portion 40 that extends radially from the base end, which is the rotation center of the rotation axis of the lower nozzle 12, to the tip. The main body portion 40 integrally includes a cleaning spray hole 41 for spraying cleaning water stored in the cleaning water tank 15, a cleaning channel 42 (see Figure 4) that extends from the rotation center to the cleaning spray hole 41 and through which cleaning water flows, a rinsing spray hole 43 for spraying rinsing water stored in the rinsing water tank 19, and a rinsing channel 44 (see Figure 4) that extends from the rotation center to the rinsing spray hole 43 and through which rinsing water flows. The lower nozzle 12 rotates in one direction when the flow of cleaning water generated in the cleaning channel 42 or the flow of rinsing water generated in the rinsing channel 44 is converted into rotational force. The lower nozzle 12 is connected to a second wash water discharge pipe 18B that supplies wash water to the wash channel 42 and a second rinse water discharge pipe 22B that supplies rinse water to the rinse channel 44.

[0051] The lower nozzle 12 is equipped with a detachment mechanism 47 for attaching and detaching the main body 40 from the lower support portion 14 provided in the washing chamber 3. The detachment mechanism 47 has a pair of knob portions 47a, 47a. As shown in Figures 6(a) and 6(b), the configuration and operation of the attachment / detachment mechanism 47, which comprises a pair of knobs 47a, 47a, a first rail portion 47b connected to one of the knobs 47a, a first engaging portion 47d slidably provided within the first rail portion 47b and attached to one of the knobs 47a via a first compression spring 47f, a second rail portion 47c connected to the other knob 47a, a second engaging portion 47e slidably provided within the second rail portion 47c and attached to the other knob 47a via a second compression spring 47g, a first pressing portion 47h connected to one of the knobs 47a, and a second pressing portion 47i connected to the other knob 47a, is the same as the configuration and operation of the attachment / detachment mechanism 37 described above, so a detailed explanation is omitted here.

[0052] As shown in Figure 2, a cleaning water tank 15 is provided at the bottom of the cleaning chamber 3 so as to protrude into the machine room 4. A filter 16 is detachably positioned between the cleaning chamber 3 and the cleaning water tank 15. A cleaning pump 17 is connected to the front of the cleaning water tank 15 via a cleaning water intake. A cleaning water discharge pipe 18 is connected to the discharge port of the cleaning pump 17. The cleaning water discharge pipe 18 branches into a first cleaning water discharge pipe 18A and a second cleaning water discharge pipe 18B. The first cleaning water discharge pipe 18A is connected to the upper nozzle 11, and the second cleaning water discharge pipe 18B is connected to the lower nozzle 12.

[0053] Inside the machine room 4, there is a rinse water tank 19 to which rinse water is supplied from the outside via a water supply pipe (not shown). A rinse pump 21 is connected to the rinse water tank 19 via a rinse water suction pipe 20. A rinse water discharge pipe 22 is connected to the discharge port of the rinse pump 21. The rinse water discharge pipe 22 branches into a first rinse water discharge pipe 22A and a second rinse water discharge pipe 22B, with the first rinse water discharge pipe 22A connected to the upper nozzle 11 and the second rinse water discharge pipe 22B connected to the lower nozzle 12.

[0054] The machine room 4 houses an electrical box (not shown) containing a controller 23 that controls the overall operation of the dishwasher 1.

[0055] The effects of the dishwasher 1 of the above embodiment will now be explained. In the dishwasher 1 of the above embodiment, at least the opposing surface of the first bearing 136(146) that faces the head portion 131A(141A) of the first shaft 131(141) is formed of PEEK resin having a hardness equivalent to that of the abrasive. In addition, in the dishwasher 1 of the above embodiment, the first shaft 131(141) is formed of stainless steel. As a result, the abrasive is prevented from getting embedded in the opposing surface of the first bearing 136(146) that faces the head portion 131A(141A) of the first shaft 131(141), and the abrasive flows out from between the bearing 135(145) and the shaft 130(140) together with the washing water.

[0056] Here, the main factors that influence the degree of ternary abrasive wear as described above include, for example, the hardness and shape of the intervening particles, the difference in hardness of the materials on the opposing surfaces, the load, the sliding distance, and the degree of particle supply. In particular, it is known that the amount of wear increases sustainably when particles are supplied continuously. Therefore, by appropriately selecting the material of the first bearing 136 (146) according to the conditions of the dishwasher 1, ternary abrasive wear can be suppressed.

[0057] In the dishwasher 1 of the above embodiment, as shown in Figure 8(A), the first bearing 136(146) is pushed toward the head portion 131A(141A) side (in the direction of the arrow) in the extending direction of the first shaft 131(141) by the water pressure during washing, and is pressed against the head portion 131A(141A) while rotating. In other words, the first bearing 136(146) is subjected to pressurized sliding against the head portion 131A(141A).

[0058] Furthermore, since the first bearing 136 (146) is a part that rotates on the shaft, the gap G2 on the body part 131B (141B) side needs to be set to be relatively narrow to prevent rattling during rotation. However, the gap G1 on the head part 131A (141A) side does not need to be as narrow as the gap G2, and is set to be slightly wider from the standpoint of sliding properties. In addition, since the first bearing 136 (146) is the attachment / detachment part of the attachment / detachment mechanism 37 (47), cleaning water inevitably gets in, but it is not a part where a large amount of cleaning water (cleaning water containing abrasives) enters, and although the amount of abrasive that enters between the first bearing 136 (146) and the first shaft 131 (141) is relatively small, this part is not washed away by rinsing water supplied from the rinsing channel 34 (44).

[0059] Based on these characteristics of the dishwasher 1, in this embodiment, the opposing surface of the first bearing 136(146) that faces the head portion 131A(141A) of the first shaft 131(141) where pressurized sliding occurs is formed of PEEK resin.

[0060] As a result, even if abrasive material gets between the bearing 135 (145) and the shaft 130 (140) during cleaning, wear on the head portion 131A (141A) of the shaft 130 (140) can be suppressed. Consequently, as shown in Figure 8(B), by suppressing the wear G0 of the head portion 131A (141A) of the shaft 130 (140), looseness in the upper nozzle 11 and the lower nozzle 12 can be suppressed.

[0061] In the dishwasher 1 of the above embodiment, the first bearing 136 (146) is made of PEEK resin. With this configuration, it is possible to easily provide a component that will become the first bearing 136 (146).

[0062] Furthermore, in conventional dishwashers, as shown in Figure 9, the design takes into account both sliding properties and wear between the shaft 112 and the second bearing 238 (248). For example, the second bearing 238 (248) is made of polyphenylene sulfide resin (PPS resin) considering durability and sliding properties, and the shaft 112 is made of stainless steel to suppress wear and so that wear mainly occurs on the second bearing 238 (248) side (in other words, so that only the second bearing 238 (248) needs to be replaced). However, in dishwashers operating in actual stores, wear sometimes occurs on the sliding surface on the shaft 112 side rather than on the second bearing 238 (248) side.

[0063] As the sliding surface between the second shaft 132(142) and the second bearing 238(248) wears down, the gap between the second shaft 132(142) and the second bearing 238(248) widens. As a result, the water flowing through the cleaning channel 32(42) in the direction of the dotted arrow in Figure 9 will flow through the gap between the second shaft 132(142) and the second bearing 238(248) in the direction of the solid arrow in Figure 9, and will flow backward through the rinsing channel 34(44) which flows in the direction of the dashed line in Figure 9.

[0064] Therefore, in the dishwasher 1 of the above embodiment, the second bearing 138 (148) is not pressed by water pressure in the direction of the arrow shown in Figure 8(A), and is not subjected to pressurized sliding. Also, since the second bearing 138 (148) is a part that rotates on the shaft, it is necessary to set the gap between the second bearing 138 (148) and the second shaft 132 (142) to be relatively narrow so that there is no rattle during rotation. Furthermore, since the second bearing 138 (148) is a part that separates the washing passage 32 (42) and the rinsing passage 34 (44), it is also necessary to set the gap to be relatively narrow. In addition, since it is a part that separates the washing passage 32 (42) and the rinsing passage 34 (44), a large amount of washing water (washing water containing abrasives) can easily enter, and a large amount of abrasive material enters the gap between the second bearing 138 (148) and the second shaft 132 (142).

[0065] Based on the characteristics of the dishwasher 1, in this embodiment, as shown in Figures 3 and 10, at least the opposing surface of the second bearing 138(148) that faces the second shaft 132(142) is formed of UHMW-PE resin. As a result, at least the opposing surface of the second bearing 138(148) that faces the second shaft 132(142) is formed of UHMW-PE resin, which has lower hardness than PEEK resin. As a result, wear on the sliding surface of the second shaft 132(142) with the second bearing 138(148) is suppressed, which increases the gap between the second shaft 132(142) and the second bearing 138(148). As a result, the possibility of water flowing through the washing channel 32(42) flowing back into the rinsing channel 34(44) can be reduced.

[0066] For the following reasons, it is preferable to form at least the opposing surface of the second bearing 138(148) that faces the second shaft 132(142) with UHMW-PE resin rather than with the same PEEK resin as the first bearing 136(146). In other words, although UHMW-PE resin has lower hardness than PEEK resin, it has high sliding properties, resulting in a finer texture on the sliding surface. Also, since the sliding surface is not a part that is subjected to pressurized sliding, even if the aforementioned "indentation" occurs, it will not be firmly fixed to the sliding surface on the second bearing 138(148) side, and the abrasive can be washed away by the rinse water flowing through the gap during the rinsing operation. Furthermore, since the water pressure is high and the rinsing channel 34(44) itself is narrow in order to wash dishes with a small amount of water, the flow is strong, and the force that washes away the abrasive is also strong.

[0067] In addition to the second bearing 138(148), the second shaft 132(142) also has a second bearing 137(147) that is rotatably positioned. However, unlike the second bearing 138(148), the second bearing 137(147) is not located within the cleaning passage 32(42), so cleaning water from the cleaning passage 32(42) does not flow into it. Therefore, although cleaning water (abrasive) adheres to the second bearing 137(147) when attaching or detaching the upper nozzle 11 (lower nozzle 12), similar to the first bearing 136(146), the abrasive is washed away during rinsing as it is adjacent to the rinsing passage 34(44), leaving almost no residue.

[0068] Therefore, the possibility of wear occurring on the second shaft 132(142) side, which occurred in the second bearing 138(148), is small. For this reason, of the second bearings 137(147) and 138(148), only the opposing surface of the second bearing 138(148) that faces the second shaft 132(142) may be formed from UHMW-PE resin. In other words, the second bearing 137(147) may remain as PPS resin.

[0069] Although one embodiment has been described above, the present invention is not limited to the above embodiment. Various modifications are possible without departing from the spirit of the invention.

[0070] In the above embodiment, the case in which the entire first bearing 136(146) is formed of PEEK resin and the entire second bearing 137(147) is formed of UHMW-PE resin was described as an example, but the invention is not limited to this. For example, the first bearing 136(146) may have only the opposing surface facing the head portion 131A(141A) of the first shaft 131(141) formed of PEEK resin. The remaining portion may be formed of PPS resin or UHMW-PE resin, etc. That is, the first bearing 136(146) may be formed of a portion made of PEEK resin and a portion made of PPS resin or UHMW-PE resin. Also, the second bearing 137(147) may have only the opposing surface facing the second shaft 132(142) formed of UHMW-PE resin. The remaining portion may be formed of PPS resin. That is, the second bearing 137(147) may be formed from a portion made of UHMW-PE resin and a portion made of PPS resin. Such first bearings 136(146) and second bearings 137(147) may be formed, for example, by insert molding.

[0071] In the above embodiment, a washing machine in which the door 7 is provided to be movable in the vertical direction was described as an example. However, it can also be applied to dishwashers and the like in which the door is provided on the front side of the washing machine body, such as an oven.

[0072] The present invention may be appropriately combined as described above as embodiments, modifications, and other modifications, without departing from the spirit of the invention. [Explanation of symbols]

[0073] 1...Dishwasher (washer), 3...Washing chamber, 11...Upper nozzle (nozzle), 12...Lower nozzle (nozzle), 13...Upper support (support), 14...Lower support (support), 32,42...Washing channel, 34,44...Rinsing channel, 37,47...Detachable mechanism, 37d,47d...First engaging part (pair of engaging parts), 37e,47e...Second engaging part (pair of engaging parts), 130,140...Shaft, 131,141...First shaft, 131A,141A...Head part, 131B,141B...Body part, 132,142...Second shaft, 135,145...Bearing, 136,146...First bearing, 136A,146A...Recess, 137,147...Second bearing, 138,148...Second bearing.

Claims

1. A washing machine comprising a washing chamber for containing an object to be washed, a nozzle that sprays water into the washing chamber while rotating in one direction, and a support part provided in the washing chamber that rotatably supports the nozzle, The nozzle is equipped with a detachment mechanism for attaching and detaching the nozzle from the support portion. The support portion comprises a first shaft and a first bearing rotatably attached to the first shaft. The attachment / detachment mechanism has a pair of engaging parts that engage with the first bearing by clamping the first bearing in a direction perpendicular to the rotation axis of the first bearing, The first shaft has a head portion that functions as a retainer for the first bearing to come off the first shaft in the axial direction, and a body portion that rotatably supports the first bearing. A washing machine wherein at least the opposing surface of the first bearing facing the head portion of the first shaft is formed of aromatic polyether ketone.

2. The washing machine according to claim 1, wherein the first shaft is made of stainless steel.

3. The washing machine according to claim 1 or 2, wherein the first bearing is formed of the aromatic polyether ketone.

4. The support portion further comprises a second shaft connected to the first shaft in the direction of extension of the first shaft, The nozzle is fitted with a second bearing that is rotatably mounted relative to the second shaft. The washing machine according to claim 1 or 2, wherein at least the opposing surface of the second bearing that faces the second shaft is formed of ultra-high molecular weight polyethylene.

5. A washing machine comprising: a nozzle provided in a washing chamber for containing an object to be washed, which sprays water into the washing chamber while rotating in one direction; a support provided in the washing chamber for rotatably supporting the nozzle; a washing channel for supplying washing water to the spray hole of the nozzle; and a rinsing channel for supplying rinsing water to the spray hole of the nozzle, The support portion has a second shaft having the rinsing channel that extends axially inside, The nozzle is fitted with a second bearing that is rotatably mounted relative to the second shaft. The second bearing is located inside the cleaning channel, which is located outside the second shaft. A washing machine wherein at least the opposing surface of the second bearing that faces the second shaft is formed of ultra-high molecular weight polyethylene.

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