JP2012254125A - Motor-driven blender - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deformation of a radiator plate by suppressing a temperature rise in bearings; to improve the durability by preventing generation of vibration and noise; and to improve the easiness in assembly while improving the accuracy in positioning bearings.SOLUTION: The motor-driven blender includes: a pair of upper and lower rolling bearings 32 fixed to a cutter rotating shaft 22 in such a way as to hold a positioning projection 30 formed in the outer periphery of the rotating shaft 22 from upper and lower sides; a cylindrical metal ring 34 pressed into outer rings of the rolling bearings 32; the radiator plate 36 with a bearing housing part 40 into which the cylindrical ring 34 is pressed from above; and a pair of upper and lower oil seals 46 and 50 which are respectively held at positions facing a rotary blade holder 12 and the bearing housing part 40 in the radiator plate 36 and whose inner peripheral lips are in contact with the rotating shaft 22.

Description

  The present invention relates to an electric mixer for pulverizing a workpiece such as a food material.

  There are various types of electric mixers of this type. Generally, an electric motor is housed in a main body case, and a rotary blade holder is attached to and detached from the main body case from above. The upper end protrudes into the workpiece container that is crowned by the rotary blade holder, a cutter (crushing blade) is fixed to this protruding end, and the lower end of the rotating shaft protrudes into the main body case to rotate the motor. It is transmitted via a rotary connector. In this case, sliding bearings such as sintered bearings using a sintered alloy or oilless bearings using oilless metal with improved lubricity are widely used as rotating shaft bearings because of their simple structure. ing.

  Since the sintered bearing is obtained by impregnating a sintered alloy with oil (lubricating oil), the oil impregnated in the metal tends to flow out when the temperature rises during high-speed rotation or high load of the rotating shaft. Oilless bearings are bearings that use materials with improved self-lubricating properties.The amount of lubrication and the number of times of lubrication are reduced to improve maintainability.However, oil supply is required, so it is necessary at high speeds and high loads. The problem remains that the temperature rises and oil tends to flow out. For this reason, there is a problem that the durability of the bearing is lowered or the oil flows out and scatters around.

  Patent Document 1 discloses a structure in which a heat-dissipating member 15 serving also as a guide is press-fitted into the outer periphery of the oilless bearing 10 in order to prevent oil flowing out from below the oilless bearing 10 due to frictional heat from scattering. Yes. Here, the upper part of the bearing 8 surrounding the outer periphery of the oilless bearing 10 is press-fitted and fixed in a container 6 made of synthetic resin.

  Patent Document 2 discloses a case in which a heat radiating plate 48 is provided in a container (receiving portion 28), and a bearing 44 made of oilless metal is fixed to the heat radiating plate 48.

  Patent Document 3 discloses that a heat sink is not required by using a shield ball bearing bearing body 231. That is, the rotary shaft portion 23 provided with the mechanical seal portion 233 above and below the ball bearing is provided on the inner bottom of the container portion 21. Here, the rotary shaft portion 23 is fixed to a bearing storage portion 221 provided between the inner bottom and the lower bearing storage body portion 22 mounted on the inner bottom (paragraphs 0027 and 0029). The one described in Patent Document 3 uses ball bearings and prevents mechanical grease from leaking by providing mechanical seals at the upper and lower ends. The assembly process can be simplified.

Shokai 57-121237 4-28845 JP-A-2005-177127

  Patent Documents 1 and 2 both use oilless bearings, and as described above, the oil scatters due to the temperature rise at high rotation and high load, or the durability of the bearing due to the decrease in oil. There is a problem that the sex goes down.

The one described in Patent Document 3 uses a ball bearing, so the temperature rise is less than when using a sliding bearing as in Patent Documents 1 and 2, but it still operates continuously for a long time at high rotation and high load. In some cases, a certain degree of temperature rise of the bearing is unavoidable.
Further, in Patent Document 3, the rotating shaft portion 23 is provided with a rotating shaft 232 attached to an existing cylindrical shield ball bearing bearing body 231, and mechanical seal portions 233 are provided above and below the bearing body 231, and the rotating shaft is mounted. There is an explanation that it protrudes vertically (paragraph 0027).

  However, since the bearing body 231 is housed in the bearing housing part 221 provided in the lower bearing housing part 22 attached to the lower surface of the container 21, the outer ring of the ball bearing bearing body 231 is directly connected to the bearing housing part 221. It will be loaded in contact with the inner surface. For this reason, the load of the bearing is directly applied to the bearing housing portion 221. In particular, since the invention of Patent Document 3 eliminates the need for a heat sink and simplifies the assembly process, it is considered that the housing portion 221 is formed of a resin or the like, and in this case, the durability is lowered. As a result, the runout of the rotary shaft 232 is likely to occur, which may cause vibration and noise. Although it is conceivable that the lower bearing housing part 22 is made of a metal such as aluminum to increase its strength and heat dissipation, the lower bearing housing part 22 is deformed by repeated application of a load during rotation of the rotating shaft, Damage to the ball bearing (particularly damage to the ball and deformation of the outer ring) occurs.

  Further, it is difficult to accurately determine the fixing position of the bearing 231 to be fixed to the rotating shaft 232, and there is a problem that the assembling property is poor. That is, since there is no positioning for assembling (press-fitting) the bearing 231 to the rotating shaft 23, it is difficult to set the height of the bearing 231 with respect to the rotating shaft 23.

  Further, after the mechanical seal portions 233 are attached to the upper and lower sides of the two bearings 231, the whole is housed in the bearing housing portion 221 of the lower bearing housing portion 22, and in this state, the lower bearing housing portion 22 is placed in the upper container body portion 21. Since it is screwed to the lower surface, there is also a problem that the assemblability is poor. That is, in the mechanical seal, the rotating ring integrated with the rotating shaft and the fixing ring fixed to the fixing portions (the lower bearing housing body portion 22 and the upper container body portion 21) are in contact with each other on a plane perpendicular to the rotating shaft. Since the two rings are pressed by a coil spring with a constant force, the structure is complicated, the mounting is troublesome, and the size becomes large.

  The present invention has been made in view of such circumstances, suppresses the temperature rise of the bearing portion by using a rolling bearing, prevents the heat sink from being deformed by a load applied to the heat sink that houses the bearing, and vibrates. Another object of the present invention is to provide an electric mixer that can prevent the generation of noise and noise, improve durability, and improve assembly accuracy while improving bearing positioning accuracy.

  According to the present invention, the object is to provide a main body case that houses the electric motor, a rotary blade holder that is detachably held in the main body case from above, and a work piece that is detachably attached to the rotary blade holder. And a cutter rotating shaft penetrating the rotary blade holder in the vertical direction. The cutter blade is held at the upper end of the cutter rotating shaft protruding into the workpiece receiving container, and the inside of the main body case. In the electric mixer in which a lower end protruding in a releasable manner is detachably engaged with the output shaft of the electric motor via a rotary connector, the cutter rotary shaft so as to sandwich the positioning convex portion formed on the outer periphery of the rotary shaft from above and below A heat sink formed with a pair of upper and lower rolling bearings fixed to a metal ring, a metal cylindrical ring press-fitted into the outer ring of these rolling bearings, and a bearing housing portion into which the cylindrical ring is press-fitted from above And an electric mixer comprising a pair of upper and lower oil seals that are respectively held at positions facing the bearing housing portion of the rotary blade holder and the heat radiating plate and whose inner peripheral lip portion contacts the rotary shaft, Is achieved.

According to the present invention, since the inner ring of the pair of rolling bearings is press-fitted into the rotating shaft so as to sandwich the positioning convex portion provided on the outer periphery of the cutter rotating shaft from above and below, each bearing is positioned by this convex portion and positioned. Accuracy is improved. In addition, the outer ring of the two bearings is press-fitted and fixed to a metal cylindrical ring, and this cylindrical ring is press-fitted into the bearing housing portion of the heat sink, so that the heat of the rolling bearing and the load of the bearing are dispersed by the cylindrical ring. It will be added to the heat sink. For this reason, the heat dissipation is improved, the deformation of the heat sink is prevented, the generation of vibration and noise is prevented, and the durability is improved.
Further, since the oil seal is used, the configuration is simple and the mounting becomes easy. This oil seal is held in advance on the bottom surface of the bearing housing and the rotary blade holder, and in this state, the preliminary assembly of the bearing, the rotating shaft, and the cylindrical ring is housed in the bearing housing. Therefore, assembly is easy.

The front view (A) and right view (B) which show the external appearance of one Example of this invention Similarly, exploded perspective view of the bearing Whole exploded perspective view Exploded perspective view of rotating shaft holder Plan view of rotary blade holder VI-VI line sectional view in FIG. Bottom view of rotary blade holder

  The rolling bearing is preferably a ball bearing (claim 2), but the present invention is not limited to this. For example, a needle bearing or a tapered bearing may be used. The convex portion may be an annular convex portion integrally formed by machining (rolling, cutting, etc.) on the outer periphery of the cutter rotating shaft (Claim 3). A body flange-like member (such as an E-ring or an annular leaf spring) may be fixed. Further, the convex portion may be a pin protruding in the radial direction from the outer periphery of the rotation shaft. Although it is desirable that the heat radiating plate is made of aluminum having good thermal conductivity (Claim 4), it is of course not limited thereto.

  The oil seal is a combination of a highly elastic rubber that forms a seal lip and a metal ring incorporated on the outer periphery. The outer periphery is fixed in advance in the oil seal housing by press fitting, and then rotated with the bearing. If a pre-assembled body in which the shaft and the cylindrical ring are integrated is loaded in the bearing housing portion and the heat radiating plate is fixed to the rotary blade holder, the assemblability is further improved.

  1, 2, and 3, reference numeral 10 denotes a substantially cylindrical main body, 12 denotes a cutter container serving as a rotary blade holder loaded in a loading chamber 10 </ b> A formed on the upper surface of the main body 10, and 14 denotes the cutter container 12. A glass container 16 serving as a workpiece storage container that is screwed in a liquid-tight manner from above, and a switch cover 16 is crowned by the glass container 14. A screw thread 14A is formed on the outer periphery in the vicinity of the opening of the glass container 14, and the cutter container 12 is removed (unscrewed) from the thread thread 14A. Cover with the cutter container 12 oriented. That is, the cutter container 12 is turned and tightened liquid-tight. Reference numeral 18 shown in FIGS. 2, 4, and 6 is a waterproof ring on which the opening edge of the glass container 14 is pressed. In this state, the entire glass container 14 and the cutter container 12 are turned upside down, and the cutter container 12 is inserted into the loading chamber 10 </ b> A of the main body 10.

  An electric motor 20 is accommodated in the main body 10, and a motor output shaft 20A of the motor 20 projects vertically upward from the center in the loading chamber 10A. In the cutter container 12, a cutter rotating shaft 22 coaxially positioned with the motor output shaft 20A is rotatably held by a bearing described later. Three cutters 12A that engage with three longitudinal grooves 10B provided in the loading chamber 10A are formed on the outer periphery of the cutter container 12, and when these longitudinal grooves 10B and the projections 12A are engaged, the cutter container Twelve rotations are restricted.

  The cutter rotation shaft 22 penetrates the cutter container 12 in the vertical direction, and the lower end thereof and the motor output shaft 20 are connected to each other via a rotary connector 24 (24A, 24B) so as to be attachable and detachable. A cutter blade 26 is fixed to the upper end of the cutter rotation shaft 22. The cutter blade 26 is rotationally driven by the electric motor 20 and cuts the workpiece in the glass container 14.

  The switch cover 16 has a substantially bowl-shaped bowl-shaped part 16A formed at a part of the lower edge thereof, and a claw (not shown) accommodated inside the bowl-shaped part 16A in a state of being covered with the glass container 14. ) Enters the switch hole 10 </ b> C (FIG. 3) provided at the upper edge of the main body 10. The switch cover 16 is given an upward return behavior by a return spring of the switch. When the switch cover 16 is pushed down against the return spring by hand, the switch is turned on and the electric motor 20 is started. If the pressing of the switch cover 16 is stopped, the switch cover 16 returns upward and the switch is turned off. Therefore, the motor 20 stops.

  Next, the bearing structure of the cutter rotating shaft 22 will be described. As shown in FIGS. 4 and 6, the bearing is formed with a positioning annular projection 30 near the center of the cutter rotating shaft 22, and a pair of upper and lower ball bearings 32, 32 sandwiching the annular projection 30 from both sides. Is fixed by press-fitting. That is, the inner rings of the ball bearings 32 and 32 are press-fitted into the cutter rotating shaft 22. A cylindrical ring 34 made of metal (such as stainless steel) is press-fitted and fixed to the outer rings of these ball bearings 32 and 32.

  Reference numeral 36 denotes a heat sink. The heat radiating plate 36 is made of a metal having good thermal conductivity such as aluminum, and is fixed to the lower surface of the cutter container 12 with screws (tapping screws) 38 (FIGS. 6 and 7). A bearing housing 40 is formed at the center of the heat radiating plate 36 so as to bulge downward, and the cylindrical ring 34 is press-fitted and fixed therein. A step portion 42 is formed on the inner peripheral surface of the bearing housing portion 40 so that the lower edge of the cylindrical ring 34 is locked. The bottom portion of the step portion 42 has a lower diameter than the outer diameter of the cylindrical ring 34. A small-diameter lower oil seal housing portion 44 is formed. A lower oil seal 46 is press-fitted and fixed here.

  Further, an upper oil seal housing portion 48 that bulges upward is formed at the center bottom of the cutter container 12. An upper oil seal 50 is fixed to the upper oil seal housing 48. The upper and lower oil seals 46 and 50 are formed by integrating a high elastic rubber serving as a seal lip and a metal ring incorporated on the outer periphery thereof, and the outer periphery thereof is fixed in advance to the respective accommodating portions 48 and 44 by press-fitting or the like. Has been. An O-ring 52 having a diameter larger than that of the bearing housing portion 40 is sandwiched between the lower surface of the cutter container 12 and the heat radiating plate 36 to prevent the lubricating oil from flowing out of the ball bearing 32.

When assembling the bearing portion, before fixing the heat radiating plate 36 to the cutter container 12, a pre-assembled body in which the cutter rotating shaft 22, the ball bearings 32 and 32, and the cylindrical ring 34 are assembled in advance is prepared. The oil seals 50 and 46 are loaded in the upper and lower oil seal accommodating portions 48 and 44, respectively. Then, after the preliminary assembly is press-fitted and fixed in the bearing housing chamber 40 of the heat radiating plate 36, both ends of the cutter rotating shaft 22 are aligned with the oil seal 50 on the cutter container 12 side and the oil seal 46 on the heat radiating plate 36 side. However, the heat radiating plate 36 is brought into close contact with the lower surface of the cutter container 12. At this time, an O-ring 52 is sandwiched between them. The radiator plate 36 may be positioned and fixed with screws 38.

10 Main body 12 Cutter container (Rotating blade holder)
14 Glass container (workpiece container)
20 Electric motor 22 Cutter rotating shaft (Rotating shaft)
24 Rotating Connector 26 Cutter Blade 30 Annular Projection 32 Ball Bearing 34 Cylindrical Ring 36 Heat Sink 40 Bearing Housing Part 42 Step 44 Lower Oil Seal Housing Part 46 Lower Oil Seal 48 Upper Oil Seal Housing Part 50 Upper Oil Seal

Claims (6)

A main body case that houses the electric motor, a rotary blade holder that is detachably held in the main body case from above, a workpiece storage container that is liquid-detachably attachable to the rotary blade holder, and the rotary blade holder A cutter rotating shaft penetrating the body in the vertical direction, and a cutter blade is held at the upper end of the cutter rotating shaft protruding into the workpiece container, and the lower end protruding into the main body case via the rotary connector In the electric mixer that is detachably engaged with the output shaft of the electric motor,
A pair of upper and lower rolling bearings fixed to the cutter rotating shaft so as to sandwich a positioning convex portion formed on the outer periphery of the rotating shaft from above and below, and a metal cylindrical ring press-fitted into an outer ring of these rolling bearings The heat sink in which the cylindrical ring is press-fitted from above is formed, and the rotary blade holder and the heat sink are held at positions facing the bearing holder, and the inner peripheral lip is rotated. An electric mixer comprising a pair of upper and lower oil seals in contact with a shaft.   2. The electric mixer according to claim 1, wherein the rolling bearing is a ball bearing.   2. The electric mixer according to claim 1, wherein the convex portion is an annular convex portion formed integrally with the cutter rotating shaft.   The electric mixer according to claim 1 or 2, wherein the heat sink is made of aluminum.   The bearing housing portion is formed so as to protrude downward from the lower surface of the rotating blade holder of the heat radiating plate. On the inner surface of the bearing housing portion, a step portion on which the lower edge of the cylindrical ring is locked, and the cylindrical shape A lower oil seal housing portion that is smaller than the outer diameter of the ring and bulges downward from the stepped portion is formed, and an upper oil seal housing portion that bulges upward is formed on the rotary blade holder. The electric mixer according to claim 1, wherein a lower oil seal is press-fitted and fixed in the oil seal housing portion, and an upper oil seal is press-fitted and fixed in the upper oil seal housing portion. 6. The electric mixer according to claim 5, wherein a preliminary assembly in which a cutter rotating shaft, a rolling bearing, and a cylindrical ring are assembled in advance is loaded in a bearing housing portion of a heat sink.

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