The article describes the repair and maintenance of the main components of electric bread machines, which differ from the options offered on the Internet and significantly increase their reliability and service life.The failure of the breadmaker can be due to various following reasons: wear of the oil seals and bearings of the bucket, breakage or extension of the belt of the drive mechanism of the blade rotation, wear of the electric motor brushes, short circuit or breakage of the motor windings, damage to the heater (TEN), network cable and parts of the electronics unit. The elimination of these damages has been described many times on the Internet, but they all boil down to replacing failed parts and assemblies that you have to buy in their respective stores.
The most unreliable knot of the bread machine is the knot of rotation of the scapula located in a bucket. This unit refuses literally after six months of normal operation of the bread machine. As a result, the bucket leaks and fills the mechanism of rotation of the scapula. The bucket drive shaft rotates in a plain bearing or in a ball bearing and gland. Due to the fact that the load on the shaft when mixing the dough is asymmetric, it also makes conical movements under the action of an asymmetric blade due to play in the bearing and the flexibility of the stuffing box. This leads to quick wear of the bearing and stuffing box. In addition, the oil seal loses its flexibility from heating when baking bread, which further accelerates its wear. In this regard, replacing worn parts with new ones does not make the stove more reliable than a new one. To eliminate this drawback, more reliable bucket drive designs are needed.
Repair and maintenance of the LG type bread machine
The easiest solution to this issue is to install two ball bearings of closed type. This decision arose during the repair of a bucket of an LG type bread machine, in which one closed-type ball bearing 608ZZ (photo 1) with an inner diameter of 8 mm and an outer diameter of 22 mm and an oil seal, which also had an outer diameter of 22 mm, was installed, so the issue was resolved very simply. Instead of an oil seal and a worn ball bearing, two new ball bearings and a homemade oil seal of a simple design were installed.
For this reconstruction, it is necessary to remove the rocker arm from the shaft, place the bucket on a soft surface with the upper part and press the shaft with the bearing and gland into the bucket with light hammer blows on the extension with a diameter of 6-7 mm. Remove the lower lock washer and oil seal, install the shaft with the bearing on the jaws of the vice and press the shaft out of the bearing.
After that, the shaft is clamped with the lower part into the electric drill chuck and polished at low speed with a zero emery cloth in a place near the flat, where the shaft will slide along the gland. Bearings are carefully mounted on the shaft from both sides until they stop in the remaining lock washer. The lower lock washer is put in place. After that, the shaft with bearings is carefully pressed into the bucket using a tube with an internal diameter of 8-9 mm and the drive arm is put in its place.
As a stuffing box, it was decided to use a silicone plate 2 mm thick. To fix the gland, two duralumin disks with a diameter of 40 mm and a thickness of 2 mm were cut. Holes with a diameter of 3.1 mm were drilled in the center of the discs. The disks are fastened together by a screw with an M3 nut. In fastened disks, at a distance of 15 mm from the center, four holes with a diameter of 2.5 mm are drilled at equal distances between them, which will be used to secure the gland.
As a mark, one hole is drilled at a distance of 12 mm from the center between the previous holes. The mark is needed to accurately align the holes, which can be slightly offset in different directions during drilling. After that, the disks are disconnected and in one disk, which will be a template, the central hole is drilled to a diameter of 8 mm. The template is put on the shaft of the bucket, pressed by hand to the bottom of the bucket and four holes with a diameter of 2.5 mm are drilled through the holes in the template.
Opposite the label on the bottom of the marker is a risk marker. The template is removed and the M3 thread is cut into the bottom of the bucket. To make the gland, another disk rests on the silicone plate, and all holes, the center and the circle are marked with a marker on it. A silicone disk with a diameter of 42 mm is cut with scissors, in which mounting holes with a diameter of 3-4 mm and a central hole with a diameter of 6-6.5 mm are punched with notches. For slots, you can use pipe segments from the telescopic receiver antennas, sharpening the working ends with a round file on the inside. In the disk that the gland will mount, the central hole is drilled with a feather drill to a diameter of 12 mm, the mounting holes are drilled to a diameter of 3.2 mm and are countersunk under countersunk heads of M3 mounting screws.
Before installing the gland on the upper bearing, a Litol-24 lubricant layer is applied and the shaft itself is slightly lubricated. The gland is put on the shaft and set according to the mark so that its holes coincide with the holes for mounting the disk, which is also installed on the mark and fastened with M3 screws with countersunk heads and a length of 10-15 mm.
This completes the repair of the bucket. The result is a gland device shown in photo 2. A bucket repaired in this way has been operating for the third year without comment. It should be noted that in a similar way, buckets of other types of bread machines can be upgraded if the drive contains ball bearings. Buckets of bread machines with plain bearings are much more difficult to repair and upgrade.In the same LG bread machine there was a failure of the rotation drive. The reason for this was a small stretching of the toothed belt and the lack of adhesion to the motor pulley. Such a belt was not available, therefore, it was decided to increase the diameter of the drive pulley by winding several layers of PVC tape. The teeth of the belt are primarily needed for coupling with a small diameter pulley of the engine, and with the large diameter pulley, due to the flexibility of the electrical tape, the clutch was sufficient for normal operation of the bread machine.
Repair with maintenance of buckets of bread machines with sliding bearings.
The complexity of the repair and maintenance of buckets with sliding bearings is that the bearing shells are small in size, not allowing them to be drilled to the diameter of ball bearings, which can be used to replace sliding bearings. Here you can not do without the help of a turner.
Before removing the shaft with the beam, it is necessary to determine its position in the guide glass. To do this, a flat plate rests on the glass and the clearance between the beam and the plate is measured with a caliper. This gap will need to be set after assembling new parts of the bucket drive.
The plain bearing race must be removed. To do this, it is necessary to carefully drill the aluminum rivets of the mounting of the guide glass and disconnect it from the bucket. To remove the clip, it is necessary to make a feather drill according to Fig. 2.
If the diameter of the holder near the end wall of the glass is more than 22 mm, then the width of the cutting insert should be increased. After making the drill, the glass is clamped in a vise with the end wall facing itself and so that the drill does not rest against the vise sponge. A drill fixed in an electric drill is inserted into the bearing bore and smoothly fed to the glass wall with the drill turned on. The drilling process occurs in the horizontal direction with little effort. When using a drilling machine, the glass is mounted in its vise wall up.
The new ferrule must be installed coaxially in the cup, as shown in Fig. 3, and secured with two diagonal M3 countersunk screws, cutting the thread in the ferrule. In Fig. 3 they are indicated by a dotted line. After that, the glass with a new clip is attached to the bucket with countersunk screws and M5 nuts.
To prevent leakage in these attachment points, epoxy adhesive must be applied under the screw heads, the excess of which must be removed after tightening the screws. Washers and ball bearings are put on the shaft to assemble the bucket drive. All this is preliminarily inserted into the holder by a sliding fit and a previously measured clearance is set, which can be adjusted by the number of washers shown in Fig. 3.
After adjustment, the shaft with bearings is removed, and the bearings are covered with a thin layer of epoxy glue, after which everything is inserted in its original place until the glue cures. In this case, it is desirable to make sure that the gap shown in Fig. 3 is not violated. The manufacture and installation of the stuffing box parts is carried out in the same way as described above for the LG type bread machine. In this embodiment, vacuum rubber 2 mm thick was used as an oil seal, which also gave a positive result.
In addition, it is very important to note that the mounting holes should not fall onto the screws that secure the holder to the cup, and it is imperative to place a thin smooth washer above the lock washer under the gland to prevent damage to the gland by the lock washer. On this repair with the maintenance of the bucket of the bread machine can be considered complete.
Author: Anatoly Zhurenkov, Zaporozhye
