JP2008193952A - Unit for supporting rotary member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a unit for supporting rotary member that is furnished with a flange on the main shaft to prevent grease leakage, and for enabling a rotary member to be rotated stably and continuously. <P>SOLUTION: The unit for supporting rotary member U1 comprises a main shaft 8 set upright extendedly in a predetermined direction, multiple bearings 2 and 4 rotatably supporting the main shaft, gears G1 and G2 set each on one side of a drive shaft and the main shaft, respectively, a rotary member 32 set on the other end side of the main shaft, and a case 40 housing the main shaft, the bearings and the gears. Inside this unit U1, a lubricant for lubricating the gears is sealed in; the main shaft is provided with a flange 27 for circulating the lubricant inside the unit U1 and for preventing foreign matters from infiltrating the gears, disposed in the closest proximity, to at least the rotary member, wherein the flange 27 is continuously disposed over the whole circumference of the main shaft so as to make a predetermined part of the main shaft widen the diameter toward the inner wall 40s of the case 40 than the other parts; and the outer circumferential part 27a of the flange 27 is set facing the inner wall of the case 40 a predetermined space L2 apart therefrom. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to, for example, a grass cutter, a brush cutter and a lawn mower used for cutting off grass (e.g., lawn and weed) growing on the ground surface from near the root, or an electric tool, a concrete drill, etc. The present invention relates to an improvement of a rotating member support unit that pivotally supports a rotating member such as a cutting blade (rotating blade) attached thereto.

FIG. 4 shows an example of a configuration of a mower provided with such a rotating member support unit. In the configuration shown in the figure, the mower A includes an operation tube 30 that extends linearly, and a rotary member support unit (hereinafter referred to as a rotary blade unit) U2 provided on one end side of the operation tube 30. A driving device (engine) 34 provided on the other end side of the operation tube 30 is provided.
In this case, the operation tube 30 is provided with a drive shaft 38 that is rotated by a drive force (rotational output) generated by the engine 34, and the drive shaft 38 is a rolling bearing (hereinafter referred to as drive shaft). (Referred to as a bearing) 6 is rotatably supported. A gear (hereinafter referred to as a drive shaft gear) G1 is provided at the end of the drive shaft 38 opposite to the engine 34, and the drive shaft bearing 6 is externally fitted to the drive shaft gear G1. The drive shaft 38 is rotatably supported.

  3 (a) and 3 (b), the rotary blade unit U2 includes a main shaft 8 extending in a predetermined direction and two rolling bearings that rotatably support the main shaft 8. (Hereinafter referred to as the rotary blade side bearing 2 (lower bearing in FIG. 3A) and the gear side bearing 4 (upper bearing in FIG. 3)) and the rotational force of the drive shaft 38 to transmit to the main shaft 8. And a pair of gears (the drive shaft gear G1 (the right gear in the figure)) provided on one end side (the left end side and the upper end side in the figure) of the drive shaft 38 and the main shaft 8, respectively. And a main shaft gear G2 (referred to as the left side gear in the figure) and a rotatable rotating member (cutting blade) 32 attached to the other end side (the lower end side in the figure) of the main shaft 8.

In this case, the main shaft 8 is erected so as to extend in a substantially vertical direction when the mower A is in use, and the drive shaft 38 has a predetermined inclination angle (drive shaft 38 with respect to the main shaft 8). And an angle formed between the main shaft 8 and the main shaft 8 and is connected to the main shaft 8 via the drive shaft gear G1 and the main shaft gear G2.
Further, the rotary blade side bearing 2 is positioned between the cutting blade 32 and the main shaft gear G2 in the middle of the extending direction of the main shaft 8, or in another way, while the gear side bearing 4 is It is positioned at the end of the main shaft 8 opposite to the cutting blade 32 (upper end in FIG. 3A). Further, the operation tube 30 is provided with a protective cover 42 (FIG. 4) for protecting the operator from the cutting blade 32 at a predetermined position near the cutting blade 32.

  According to such a configuration, when the engine 34 rotates the drive shaft 38, the rotational force is transmitted to the main shaft gear G2 via the drive shaft gear G1, and the main shaft 8 can be rotated by the rotational force. Thereby, while changing the direction of the rotational force generated from the engine 34, the cutting blade 32 attached to the main shaft 8 can be rotated while the speed is reduced. The operator can cut the vegetation by moving the cutting blade 32 while supporting the whole of the mower A by the operation handle 36 attached to a predetermined position of the operation tube 30 near the engine 34.

  By the way, regarding such a mower, various measures for improving convenience and safety have been conventionally known. For example, Patent Document 1 discloses a configuration of a mower capable of arbitrarily changing the angle of a connection pipe (operation pipe), thereby facilitating the mowing of vegetation even on sloping ground. And the convenience of the mower is improved. On the other hand, for example, Patent Document 2 discloses a configuration of a mower capable of easily and reliably attaching a cutting blade (rotating blade) to a main shaft, whereby the cutting blade (rotating blade) can be removed from the main shaft. It is possible to effectively prevent the detachment and improve the safety of the mower.

  Further, in this mower A, the friction and wear of the portions where the teeth of the drive shaft gear G1 and the main shaft gear G2 contact each other are reduced, and the rotary blade side bearing 2, the gear side bearing 4 and the drive shaft bearing 6 are prevented from seizing. For the purpose of extending the fatigue life, etc., the gears G1, G2 and the bearings 2, 4, 6 can be lubricated. As a result, the cutting blade 32 can be stably and smoothly over a long period of time. It can be rotated, and the convenience and safety of the mower A can be improved.

  Therefore, for example, in order to lubricate the drive shaft gear G1 and the main shaft gear G2, grease containing extreme pressure agent (hereinafter referred to as gear lubrication grease) is contained in the predetermined space S surrounding the gears G1 and G2. It is filled (enclosed) so as to have a volume ratio of approximately 70% to 100% with respect to the space volume of the part S. In this case, the gear lubrication grease is a consistency No. specified by the National Lubricating Grease Institute (NLGI). As an example, the grease is composed of lithium soap as a thickener and mineral oil as a base oil.

  At that time, as an example, the gear side bearing 4 is a so-called open type (open type) bearing in which a sealing member (contact type seal, non-contact type seal or shield, etc.) is not provided. In contrast to the structure, the rotary blade side bearing 2 has a sealed type bearing structure in which contact type rubber seals 20 and 22 are interposed between the inner and outer rings 10 and 12. Is a sealed ball bearing incorporated between the inner and outer rings 10,12. In order to lubricate the rotary blade side bearing 2, the rotary blade side bearing 2 has, as an example, a grease in which the thickener is lithium soap and the base oil is a mineral oil (hereinafter referred to as bearing lubrication grease). ) Is enclosed inside the bearing. In this case, as an example, the rubber seals 20 and 22 have their outer diameter portions fixed to the outer ring 12 of the rotary blade side bearing 2, and their inner diameter portions (lip portions) 20 l and 22 l of the rotary blade side bearing 2. It is positioned so as to be in sliding contact with the seal groove formed in the inner ring 10.

In the rotary blade unit U2 in which the gears G1 and G2 and the bearings 2 and 4 are lubricated in this way, the rotary blade side bearing 2 is always provided only via the rubber seal (seal located on the gears G1 and G2 side) 20. In contact with gear lubrication grease.
Further, when the mower A is in use, the drive shaft gear G1 and the rotary blade side bearing 2 and the main shaft gear G2 and the rotary blade side bearing 2 are arranged vertically with the gears G1 and G2 facing upward. A large amount of grease is deposited on the outer surface of the rubber seal 20 located on the gears G1, G2 side (surface on the gears G1, G2 side) by its own weight, and presses the rubber seal 20. In addition, the outer surface of the rubber seal 20 (gear G1) where the gear lubrication grease is located on the gears G1 and G2 side is also caused by the pressure change in the space S due to the rotation of the main shaft 8 and the vibration due to the rotation of the rotary blade side bearing 2. , G2 side surface) and the seal 20 is pressed.

When the rubber seal 20 continues to be pressed by the gear lubrication grease, as a result, the gear lubrication grease is transferred from the sliding contact portion between the lip portion 201 of the seal 20 and the seal groove of the rotary blade side bearing 2 to the rotary blade side bearing. 2 may leak into (intrude).
In this case, for example, grease having a configuration similar to gear lubrication grease is applied as grease (bearing lubrication grease) sealed in the rotary blade side bearing 2, so that the bearing lubrication grease is mixed with the gear lubrication grease. As a result, it is possible to minimize the quality change or malfunction of the grease.
JP 2004-194521 A JP-A-8-130959

  However, when leakage (penetration) of the gear lubrication grease as described above proceeds into the bearing, the amount of grease in the rotary blade side bearing 2 increases from the set value, and stirring and shearing are activated, and the grease is It may soften. When such softening of the grease occurs, the sliding contact portion between the lip portion 22l of the rubber seal 22 of the rotary blade side bearing 2 (the seal located on the cutting blade 32 side) and the seal groove of the rotary blade side bearing 2, The grease may leak out of the rotary blade side bearing 2 from the air holes 22h provided in the seal 22 or the like. In this case, for example, the leaked grease adheres to the cutting blade 32 (the state of the grease Gb in FIG. 3A), which may deteriorate the rotational accuracy of the cutting blade 32, and also against vegetation and soil. There is also a risk of adverse effects.

  Further, when the gear lubrication grease continuously leaks (enters) into the rotary blade side bearing 2 and further to the outside of the rotary blade side bearing 2, the drive shaft gear G1 and the main shaft gear G2 become insufficiently lubricated. Since the teeth of the gears G1 and G2 are rubbed against each other and worn, the gears G1 and G2 may not rotate smoothly, and their rotational accuracy may deteriorate.

  As a measure for avoiding such inconvenience, for example, as a gear lubrication grease, the NLGI consistency is No. 3 or No. No. 4 grease, that is, NLGI consistency No. Grease harder than grease No. 2 is applied to suppress softening due to stirring or shearing of the grease, and the grease is adhered to the inner wall of the predetermined space S surrounding the drive shaft gear G1 and the main shaft gear G2. There are measures and measures to reduce the filling amount (filling amount) of the grease.

  However, when the hardness of the gear lubrication grease is increased, the fluidity of the grease decreases and the amount of grease that contributes to the lubrication of the drive shaft gear G1 and the main shaft gear G2 decreases. As a result, the gears G1 and G2 are lubricated. For example, as in the case described above, the teeth of the gears G1 and G2 may be rubbed against each other and worn. On the other hand, when the filling amount (encapsulation amount) of the gear lubrication grease is decreased, the grease does not sufficiently spread into the space S, and as a result, the drive shaft gear G1 and the main shaft gear G2 become insufficiently lubricated, and the same situation occurs. It may become.

  The present invention has been made in order to solve such a problem. The purpose of the present invention is to circulate the lubricant in the unit and to prevent foreign matter from entering a bearing disposed at least closest to the rotating member. In order to prevent intrusion, a flange is provided on the main shaft to prevent leakage of grease enclosed inside to the outside and to keep the rotating member rotating stably with a constant rotational accuracy over a long period of time. It is an object of the present invention to provide a rotating member support unit capable of performing the above.

  In order to achieve such an object, a rotating member support unit according to the present invention is rotated by a main shaft extending in a predetermined direction, a plurality of bearings rotatably supporting the main shaft, and a driving device. In order to transmit the rotational force of the driven shaft to the main shaft, at least one set of gears provided on one end side of the drive shaft and the main shaft and meshing with each other, and a rotating member attached to the other end side of the main shaft And a case for housing the main shaft, the bearing and the gear. In such a rotating member support unit, a lubricant for lubricating the gear is sealed in the unit, and the main shaft is used for circulating the lubricant in the unit, and at least the rotating member is recently installed. A flange for preventing foreign matter from entering the inside of the bearing arranged in contact with the flange is provided, and the flange expands a predetermined portion of the main shaft toward the inner wall of the case as compared with other portions. Thus, it is continuously arranged over the entire circumference of the main shaft, and has a structure in which the outer peripheral portion is opposed to the inner wall of the case at a predetermined interval.

In this case, the case is provided with a facing portion on the inner wall facing the gear on one end side of the drive shaft at a predetermined interval on the inner wall, and the flange has a predetermined end surface on the gear side in the axial direction than the facing portion. It is preferable to position so as to protrude by the height.
Further, it is preferable that the axial thickness of the flange and the dimensional ratio of the facing distance between the flange outer peripheral portion and the case inner wall are set to be larger than 20: 1.
In addition, what is necessary is just to set the diameter of the inner wall of the case larger than each outer diameter of the flange, the gear provided on one end side of the main shaft, and the bearing disposed closest to the gear.
Further, a cutting blade for cutting off the vegetation growing on the ground surface from the vicinity of the root can be attached to the main shaft as a rotating member.

  According to the rotating member support unit of the present invention, in order to circulate the lubricant in the unit and to prevent foreign matter from entering the inside of the bearing disposed at least closest to the rotating member, By providing the flange, it is possible to prevent the grease enclosed inside from leaking to the outside and to keep the rotating member rotating stably with a constant rotational accuracy over a long period of time.

  Hereinafter, a rotating member support unit according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the present invention, for example, a mower, a brush cutter, a lawn mower, a power tool, a concrete drill, or the like, the main shaft extends in a predetermined direction, and supports various rotating members that rotate together with the main shaft. Although it can be applied to a rotating member support unit, in the following, a rotating blade (rotating blade) for cutting away vegetation growing on the ground surface from near the root is used for a mower attached to the main shaft as a rotating member. A configuration of the rotary blade unit will be described assuming a blade unit as an example. In this case, as an overall configuration of the mower according to the present embodiment, the same configuration as that of the conventional mower A (FIG. 4) described above is assumed as an example. Further, since the basic configuration of the rotary blade unit according to the present embodiment is the same as the conventional rotary blade unit U2 (FIG. 3A) described above, the configuration is the same as or similar to the rotary blade unit U2. Are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

  FIGS. 1A and 1B show a rotary blade unit U1 (rotary member support unit) of a mower according to an embodiment of the present invention. The rotary blade unit U1 has a predetermined direction. The main shaft 8 receives the rotational force of the extended main shaft 8, the plurality of rolling bearings 2 and 4 that rotatably support the main shaft 8, and the drive shaft 38 rotated by the drive device (engine 34 (see FIG. 4)). For transmission, at least one set of gears G1, G2 provided on one end side (left end side and upper end side in FIG. 1A) of the drive shaft 38 and the main shaft 8 and meshing with each other, A rotating member (cutting blade 32) attached to the other end side (the lower end side of FIG. 1A) is provided.

  The main shaft 8, the rolling bearings 2, 4 and the gears G1, G2 are respectively housed in a cylindrical case 40, and the cutting blade 32 is fastened and fixed to the main shaft 8 by a fastening member (screw). It is attached to the outside of the case 40 (the lower side of FIG. 1A).

The main shaft 8 is erected so as to extend in a substantially vertical direction when the mower is in use, whereas the drive shaft 38 has a predetermined inclination angle (with respect to the drive shaft 38). And an angle formed between the main shaft 8 and the main shaft 8 via the drive shaft gear G1 and the main shaft gear G2. The inclination angle is arbitrarily set according to, for example, the usage environment or purpose of use of the mower, and is not particularly limited here. As an example, in the present embodiment, the drive shaft 38 is the main shaft 8. Is inclined at an inclination angle of about 120 ° (about 30 ° with respect to the cutting blade 32 in another way) (FIG. 1A).
Further, in the configuration shown in FIGS. 1A and 1B, the main shaft 8 has a relatively large diameter portion on the gears G1, G2 side (upper side in the figure) with a predetermined stepped portion 8g as a boundary. 8a is provided, and a small diameter portion 8b having a relatively small diameter is provided on the cutting blade 32 side (lower side in the figure).

  In the configuration shown in FIG. 1A, the rotary blade unit U1 includes, as an example, two rolling bearings (the rotary blade side bearing 2 (the lower bearing in FIG. 1A)) and the gear side bearing 4 (the same figure). The rotary blade side bearing 2 and the gear side bearing 4 are externally fitted to the main shaft 8 and are internally fitted to the case 40 so that the main shaft 8 can be rotated freely. I support it. In this case, as an example, the rotary blade side bearing 2 is positioned between the cutting blade 32 and the gear G2 (main shaft gear to be described later) approximately in the middle of the extending direction of the main shaft 8, in another way. The gear-side bearing 4 is positioned at the end of the main shaft 8 opposite to the cutting blade 32 (the upper end in FIG. 1A).

  In the configuration shown in FIG. 1A, the rotary blade unit U1 includes, as an example, a set of gears (drive shaft gear G1 (the gear on the right side in FIG. 1A)) and main shaft gear G2 (shown in FIG. 1A). The left side gear)) is provided, the drive shaft gear G1 is externally fitted to the drive shaft 38, and the main shaft gear G2 is externally fitted to the main shaft 8 to mesh with each other. As a result, the drive shaft gear G1 and the main shaft gear G2 rotate the cutting blade 32 attached to the main shaft 8 while changing the direction of the rotational force generated by the engine 34 (FIG. 4) and reducing the speed thereof. It fulfills the function of a so-called transmission.

  The type, size, shape, number of teeth, pitch, and the like of the drive shaft gear G1 and the main shaft gear G2 are arbitrarily set according to the size of the drive shaft 38 and the main shaft 8, the positional relationship between the two shafts, and the like. Therefore, there is no particular limitation here. For example, as in the case of the mower according to the present embodiment, the drive shaft 38 and the main shaft 8 are connected at a predetermined inclination angle (for example, about 120 °) (see FIG. 1A). As the drive shaft gear G1 and the main shaft gear G2, bevel gears such as a bevel gear, a helical bevel gear, and a spiral bevel gear may be applied.

  In the present embodiment, the rotary blade side bearing 2, the gear side bearing 4 and the drive shaft bearing 6 are composed of a rotating wheel (hereinafter referred to as an inner ring) and a stationary ring (hereinafter referred to as an inner ring), as shown in FIGS. (Referred to as outer rings) are arranged so as to be relatively rotatable, and a plurality of rolling elements (balls) are incorporated between the inner and outer rings so as to be capable of rolling. In this case, the rolling elements (balls) are tracked by the inner ring and the outer ring in a state where the rolling elements (balls) are rotatably held one by one in a pocket formed in an annular cage (for example, a corrugated matching cage). It is integrated between the faces. Thereby, each rolling element (ball) can roll between the inner and outer rings (between the raceway surfaces) without the rolling surfaces contacting each other, and as a result, each rolling element (ball) It is possible to prevent an increase in rotational resistance or seizure due to friction caused by contact with each other.

  The type and size of the rotary blade side bearing 2, the gear side bearing 4, the drive shaft bearing 6, and the rolling elements (balls) and the cage are, for example, the size of the mower and the rotational output of the drive device (engine). Since it is arbitrarily set according to the above, there is no particular limitation here. For example, as each of the bearings 2, 4, and 6, a single row deep groove ball bearing shown in FIGS. 1A and 1B, a double row deep groove ball bearing, various roller bearings, and the like can be applied. . In addition to the balls shown in FIGS. 1 (a) and 1 (b), rollers such as cylindrical rollers, tapered rollers, and spherical rollers (rolled rollers) may be applied as the rolling elements. Further, as the cage, a so-called corrugated cage, a crown cage, a cage cage, or the like may be applied.

  In this case, as an example, the rotary blade side bearing 2 has rolling elements (balls) sandwiched between inner and outer rings, and the rotary blade side toward both sides (the upper side and the lower side of FIGS. 1A and 1B). Sealing members (not shown, corresponding to rubber seals 20 and 22 shown in FIG. 3B (hereinafter referred to as seals)) for sealing the bearing 2 are provided. By providing the seal in this way, foreign matter (for example, cut wood scraps, muddy water, dust, etc.) enters the inside from the outside of the rotary blade side bearing 2 (that is, the outside of the rotary blade unit U1). In addition, the lubricant (for example, bearing lubrication grease described later) is prevented from leaking to the outside. Further, gear lubrication grease, which will be described later, is prevented from leaking (penetrating) into the rotary blade side bearing 2 and mixed with the bearing lubrication grease.

  Of the two seals, a seal (not shown but corresponding to the rubber seal 22 shown in FIG. 3B) located on the cutting blade 32 side (the lower side of FIGS. 1A and 1B), which is a rotating member. ) Is provided with a through hole (corresponding to the through hole 22h shown in the figure) for suppressing a pressure change inside the bearing. On the other hand, of the two seals, a rubber seal 20 (not shown, but shown in FIG. 3B) is located on the drive shaft gear G1 and main shaft gear G2 side (the upper side of FIGS. 1A and 1B). Is not provided with a through hole for suppressing a pressure change inside the bearing, that is, a through hole corresponding to the through hole formed in the above-described seal on the cutting blade 32 side.

  As described above, in the rotary blade side bearing 2, the drive shaft gear G1 and the main shaft gear G2 side (the upper side of FIGS. 1A and 1B) are completely sealed by the seal, whereas the inside is completely sealed. The cutting blade 32 side (the lower side of FIGS. 1A and 1B) is not completely sealed because a through hole is formed in the seal. That is, the inside of the rotary blade side bearing 2 is openable to the outside of the bearing through the through hole of the above-described cutting blade 32 side seal, and the inside air is discharged from the through hole to the outside of the bearing. In addition, the structure allows the outside air to flow into the bearing.

  In the present embodiment, the rotary blade unit U1 which is a rotary member support unit is supplied with a lubricant (for example, bearing lubrication grease described later) sealed to lubricate the drive shaft gear G1 and the main shaft gear G2. In order to circulate in U1 and foreign matter (for example, gear lubrication grease, dust, etc.) intrude into the inside of the rotary blade side bearing 2, which is a bearing disposed closest to the rotary member (cutting blade 32). In order to prevent this, a flange 27 is provided for the main shaft 8. In this case, the flange 27 has a diameter larger than that of the other portion toward a predetermined portion of the main shaft 8 toward the inner wall of the case 40 (a wall portion forming a predetermined space S surrounding the drive shaft gear G1 and the main shaft gear G2). As shown in the figure, the main shaft 8 is continuously arranged over the entire circumference, and the outer peripheral portion 27a is opposed to the inner wall 40s of the case 40 at a predetermined interval.

  As an example, in the configuration shown in FIGS. 1A and 1B, the outer diameter is smaller than the diameter dimension of the inner wall 40 s of the case 40, and the inner diameter is set to be substantially the same as the diameter dimension of the small diameter portion 8 b of the main shaft 8. The flange 27 is configured to have a substantially cylindrical shape. As described above, in the present embodiment, the flange 27 is separated from the main shaft 8, but the flange 27 may have an integral structure with the main shaft 8.

  The flange 27 is fixed to the small-diameter portion 8b of the main shaft 8 (for example, an interference fit with a predetermined tightening allowance). In this state, the outer peripheral portion 27a is opposed to the inner wall 40s of the case 40 with a predetermined interval. At the same time, an end surface (the lower surface of FIGS. 1A and 1B (hereinafter referred to as a flange lower surface) 27d on the rotary blade side bearing 2 side is in close contact with the side surface of the inner ring of the rotary blade side bearing 2. Further, in this case, the flange 27 has a predetermined size of a portion (hereinafter referred to as a reduced diameter portion) 27b facing the seal of the rotary blade side bearing 2 (not shown, but corresponding to the rubber seal 20 shown in FIG. 3B). The diameter is reduced so that the seal faces the seal with a predetermined interval. As an example, in the configuration shown in FIGS. 1A and 1B, the flange 27 is configured by reducing the diameter of the reduced diameter portion 27b until it becomes slightly smaller than the outer diameter of the inner ring of the rotary blade side bearing 2. ing.

  Here, the size of the flange 27 can be arbitrarily set according to, for example, the size of the main shaft 8 and the size of the case 40, but the flange 27 is fixed to the main shaft 8 in the case 40. The inner shaft 40s, the rotary blade side bearing 2 (outer ring and seal), the main shaft 8, the rotary blade side bearing 2 (inner ring), and the gears G1 without contacting any of the drive shaft gear G1 and the main shaft gear G2. Therefore, it is preferable to set the maximum dimension within a range where G2 can rotate smoothly. In other words, the flange 27 is the distance between the outer peripheral portion 27a and the inner wall 40s of the case 40 (distance L2 shown in FIG. 1B), and the distance between the reduced diameter portion 27b and the seal of the rotary blade side bearing 2. (Distance L4 shown in the figure), and the distance between the drive shaft gear G1 and the main shaft gear G2 end face (the upper face in the figure (hereinafter referred to as the flange upper face) 27c and the drive shaft gear G1 (shown in the figure) It is preferable to set the distance L1) to a predetermined size so that all of them are as small as possible. These intervals L2, L4, and L1 may be set to the minimum intervals in consideration of, for example, the assembly accuracy of the rotary blade unit U1 and the swinging of the drive shaft gear G1 and the main shaft gear G2.

  As an example, in the configuration shown in FIG. 1B, the interval L4 between the reduced diameter portion 27b and the seal of the rotary blade side bearing 2 is about 0.1 mm, and the interval L2 between the outer peripheral portion 27a and the inner wall 40s of the case 40 is as follows. The outer diameter dimension of the flange 27 (distance L33 shown in the figure) and the thickness dimension (distance shown in the figure) so that the distance L1 between the flange upper surface 27c and the drive shaft gear G1 is about 4 mm. L5) is set, and the flange 27 is configured. In this case, the outer diameter L33 of the flange 27 is set substantially the same as the outer diameter of the main shaft gear G2 (distance L8 shown in FIG. 1B), the thickness L5 is set to about 5 mm, and the flange 27 Is configured.

  The flange 27 needs to be positioned so that the flange upper surface 27c protrudes by a predetermined height upward in the axial direction from a portion 40t facing the inner wall 40s (hereinafter referred to as a facing portion). In this case, the facing portion 40t is provided with respect to the inner wall 40s of the case 40 so as to face the drive shaft gear G1 with a predetermined interval. As an example, in the present embodiment, the thickness L5 of the flange 27 is set so that the protrusion height (distance L6 shown in FIG. 1B) of the flange upper surface 27c with respect to the facing portion 40t is about 1 mm. Assume that the flange 27 is positioned with respect to the main shaft 8. In this case, the thickness L5 of the flange 27 is such that the flange upper surface 27c protrudes from the facing portion 40t of the case 40 in the axial direction (vertical direction in FIG. 1B) at a predetermined height (for example, distance L6). If the protrusion height L6 is a positive dimension (greater than 0), the specific dimension is not particularly limited to the above-described dimension (about 5 mm).

  Furthermore, the dimensional ratio between the thickness L5 of the flange 27 and the facing distance L2 between the outer peripheral portion 27a and the inner wall 40s of the case 40 is set to be larger than 20: 1, that is, the thickness L5 with respect to the facing distance L2. It is preferable to set the size (outer diameter L33 and thickness L5) of the flange 27 so that the ratio (L5 / L2) is greater than 20. In the present embodiment, as an example, the ratio of the thickness L5 to the facing distance L2 (L5 / L2) is set to 50, and the flange 27 is configured.

Here, when the rotary blade unit U1 is assembled, the flange 27, the main shaft gear G2, and the gear-side bearing 4 are attached to the main shaft 8 and integrated with each other in the axial direction (FIG. 1). It is assembled to the case 40 from the lower side of (a) and (b).
For this reason, the case 40 has an outer diameter L33 of the flange 27, an outer diameter L8 of the main shaft gear G2, the diameter of the inner wall 40s facing the outer peripheral portion 27a of the flange 27 (distance L3 shown in FIG. 1B), In addition, it is necessary to configure the outer diameter dimension of the gear side bearing 4 (the distance L7 shown in the figure) to be larger than the outer diameter dimension. Therefore, the outer diameter L33 of the flange 27 is close to the outer diameter L8 of the main shaft gear G2 and the outer diameter L7 of the gear-side bearing 4, and is a predetermined dimension slightly smaller than the diameter L3 of the inner wall 40s of the case 40. It is preferable to set. In the present embodiment, as an example, the gear side bearing 4 and the main shaft gear G2 are configured by setting the outer diameter size L7 of the gear side bearing 4 to be smaller than the outer diameter size L8 of the main shaft gear G2.
Thereby, the main shaft 8 integrated with the flange 27, the main shaft gear G2, and the gear side bearing 4 can be smoothly assembled to the case 40, and the outer peripheral portion 27a of the flange 27 fixed to the main shaft 8 and the case The distance L2 between the inner wall 40s and the inner wall 40s can be made as small as possible.

  According to such a configuration, the flange 27 rotates together with the main shaft 8 as the main shaft 8 rotates, and the outer peripheral portion 27a is separated from the inner wall 40s of the case 40 by a predetermined distance (distance L2 shown in FIG. 1B). ) Can be made to face each other. At this time, the flange 27 has a reduced diameter portion 27b with a seal of the rotary blade side bearing 2 (not shown but corresponds to the rubber seal 20 shown in FIG. 3B) and a predetermined interval (distance L4 shown in FIG. 1B). The flange upper surface 27c can be opposed to the drive shaft gear G1 with a predetermined distance (distance L1 shown in the figure).

  The attachment method of the flange 27 is not particularly limited to the interference fitting (fitting) as described above, and an adhesive member such as an adhesive is used as the main shaft according to the size, shape and material of the flange 27, for example. 8 may be applied and bonded to the peripheral surface, or may be attached to the main shaft 8 by joining by welding or fastening by fastening members (screws, pins, etc.), and these various methods. May be attached in combination.

Further, in the configuration shown in FIG. 1B, as an example, in a state where the flange 27 is fixed (tightened) to the main shaft 8, the flange lower surface 27d of the flange 27 is connected to the side surface of the inner ring of the rotary blade side bearing 2 ( The flange 27 is fixed to the main shaft 8 (for example, interference fitting (fitting), joining (adhesion or welding), fastening, etc.), and the flange lower surface 27d. May be positioned close to each other at a predetermined interval without being brought into close contact with the side surface of the inner ring.
In this case, the flange 27 may be configured in a cylindrical shape having the same diameter from one end side to the other end side in the axial direction, omitting the reduced diameter portion 27b.

  In the configuration shown in FIGS. 1A and 1B, the main shaft gear G2 is positioned above the drive shaft gear G1 in the extending direction of the main shaft 8 (vertical direction (vertical direction in FIG. 1)). Therefore, when setting the size of the flange 27, it is only necessary to consider reducing the distance between the flange upper surface 27c and the outer peripheral portion 27a and the drive shaft gear G1 as much as possible. However, when the relative positional relationship between the drive shaft gear G1 and the main shaft gear G2 in the vertical direction is reversed, that is, when the main shaft gear G2 is positioned below the drive shaft gear G1 in the vertical direction, What is necessary is just to set the magnitude | size of the flange 27 so that the space | interval of the flange upper surface 27c and the said main shaft gear G2 may become as small as possible.

  Here, when the flange 27 is fixed to the main shaft 8, the flange 27 contacts the inner wall 40 s of the case 40, the rotary blade side bearing 2 (seal), and the drive shaft gear G 1 and the main shaft gear G 2. Size (shape), that is, the distance L2 between the outer peripheral portion 27a and the inner wall 40s of the case 40, the distance L4 between the reduced diameter portion 27b and the seal (not shown) of the rotary blade side bearing 2, and the flange upper surface 27c. The shape is not particularly limited as long as the distance L1 to the drive shaft gear G1 can be made as small as possible, and may be any shape according to the shape of the main shaft 8 and the case 40.

  In the configuration shown in FIGS. 1A and 1B, as an example, the flange upper surface 27c of the flange 27 is formed into a flat surface that does not incline in the axial direction over the entire circumference. May be formed in a flat surface shape in which the flange upper surface 27c is inclined to one side in the axial direction (for example, gradually inclined downward in the axial direction as it goes in the diameter-enlarging direction). Further, for example, the flange 27 may be formed such that the upper surface 27c of the flange is continuous in an uneven shape (as an example, a wave shape) along the circumferential direction.

  As in the case of setting the size of the flange 27 described above, in the configuration shown in FIGS. 1A and 1B, when setting the shape of the flange 27, the distance from the drive shaft gear G1 is set as much as possible. What is necessary is just to consider making it small. Similarly, when the main shaft gear G2 is positioned below the drive shaft gear G1 in the vertical direction, the flange 27 shape may be such that the distance between the flange upper surface 27c and the main shaft gear G2 is as small as possible. .

  Further, the number of flanges 27 is not limited to one as shown in FIGS. 1A and 1B, and may be two or more. For example, the thickness L5 of the flange 27 is approximately half of the configuration shown in the figure (as an example, 2.5 mm), and the two flanges 27 are closely concentrically stacked and stacked, or at a predetermined interval. Alternatively, it may be a multi-layer flange assembly arranged concentrically.

Further, the material of the flange 27 is not particularly limited, and for example, the flange 27 can be made of any material according to the material of the main shaft 8 and the case 40. In the present embodiment, the flange 27 is A case of a predetermined metal (such as a ferrous metal or a non-ferrous metal such as an aluminum alloy) is assumed as an example. In this case, the flange 27 may be formed integrally with the main shaft 8 by, for example, molding. The flange 27 may be made of a predetermined resin (for example, a polyamide-based resin), and the resin flange 27 may be formed by injection molding, mold molding, or the like so as to have a separate structure from the main shaft 8.
However, in consideration of lubrication with respect to the rotary blade unit U1, it is preferable to apply various metal materials and resin materials that do not cause alteration to the gear lubrication grease described later.

  In the rotary blade unit U1 configured as described above, as in the case of the conventional mower A described above, in order to rotate the cutting blade 32 stably and smoothly over a long period of time, the drive shaft gear G1 and the main shaft The gears G1, G2 and the bearing 2 are lubricated for the purpose of reducing friction and wear at the parts where the teeth of the gear G2 contact each other, preventing seizure of the rotary blade side bearing 2, and extending the fatigue life. ing.

  In this embodiment, as an example, a consistency No. defined by the National Lubricating Grease Institute (NLGI) in a predetermined space S surrounding the drive shaft gear G1 and the main shaft gear G2. No. 2 (consistency number 2) grease (hereinafter referred to as gear lubrication grease) is filled (enclosed) so that the volume ratio of the space S is approximately 80%.

If the amount of gear lubrication grease filled (encapsulated) is too large, the softening of the grease is promoted by heat generated by stirring. On the other hand, if the amount is too small, the grease does not reach the space S sufficiently, resulting in poor lubrication. End up. For this reason, in the present embodiment, the filled (encapsulated) gear lubricating grease is not excessively agitated and promotes softening of the grease, and as an optimal filling amount (encapsulated amount) that sufficiently extends into the space S. The gear lubrication grease is filled (enclosed) in an amount that is approximately 80% of the volume of the space S. In this case, the space 27 is not mounted on the flange 27 (FIG. 1A) as in the conventional rotary blade unit U2 (FIG. 3A) by an amount corresponding to the volume of the flange 27. It becomes smaller than the case of.
However, the amount of filling (encapsulation) of the gear lubrication grease does not have to be strictly about 80% of the volume of the space S, for example, about 30 to about the volume of the space S. It may be filled (enclosed) in an amount of 90% volume ratio, more preferably about 50-80% volume ratio.

  Similarly, the NLGI consistency No. is also applied to the inside of the rotary blade side bearing 2. 2 grease (hereinafter referred to as bearing lubrication grease) is filled (enclosed). In this case, the amount of filling (encapsulation) of the bearing lubrication grease may be arbitrarily set according to the purpose of use and use conditions of the rotary blade unit U1, but is approximately 25 with respect to the space volume in the rotary blade side bearing 2. It is preferable to fill (enclose) in an amount that gives a volume ratio of ˜35%.

  In addition, since the component structure of a gear lubrication grease and a bearing lubrication grease is arbitrarily set, for example according to the use purpose of the rotary blade unit U1, use conditions, etc., it does not specifically limit here. For example, the gear lubrication grease and the bearing lubrication grease may be configured as lithium soap as the thickener and mineral oil as the base oil. In this case, an extreme pressure agent may be added as an additive to the thickener and the base oil.

Here, the use state of the mower according to the present embodiment, that is, the state change of the gear lubricating grease during the operation of the rotary blade unit U1 will be described below.
The gear-lubricating grease contacts the flange upper surface 27c of the flange 27 by its own weight, and by the vibration caused by the rotation of the main shaft 8 and the main shaft gear G2 while the drive shaft 38 and the drive shaft gear G1 rotate.

In this state, the flange 27 is also rotated together with the main shaft 8 by the rotation of the main shaft 8, and therefore, the gear 27 is caused by the rotation of the flange 27 with respect to the gear lubricating grease contacting the flange upper surface 27 c of the flange 27. Centrifugal force acts.
As a result, the gear lubricating grease to which the centrifugal force is applied moves upward along the inner wall 40s of the case 40 (space portion S), the surface of the drive shaft gear G1, and the surface of the main shaft gear G2 by the centrifugal force. To do. Then, after the gear lubricating grease reaches the vicinity of the main shaft 8, it again comes into contact with the flange upper surface 27 c of the flange 27 due to its own weight and vibration due to the rotation.

  Thus, the gear lubrication grease repeats circulation in the space S when the mower is in use, that is, when the rotary blade unit U1 is in operation. For this reason, the gear lubrication grease is provided on the flange upper surface 27c of the flange 27, and thus on the outer surface of the seal of the rotary blade side bearing 2 (not shown, but on the drive shaft gear G1 and main shaft gear G2 side of the seal 20 shown in FIG. 3B). (Corresponding to this surface) does not stay (deposit) and does not press the seal (see the figure). As a result, it is possible to prevent the gear lubricating grease from leaking (invading) into the rotary blade side bearing 2.

Further, in the present embodiment, the flange 27 is provided by reducing the distance from the drive shaft gear G1 as much as possible without contacting the drive shaft gear G1 (as an example, the distance L1 between the flange upper surface 27c and the drive shaft gear G1). Is set to about 4 mm), the gear lubricating grease can be easily drawn into the drive shaft gear G1. Furthermore, the gear lubrication grease drawn into the drive shaft gear G1 can be easily moved to the main shaft gear G2 via teeth that mesh with each other.
Thereby, in the space S, the flow of the gear lubrication grease can be activated (circulation is promoted), and the drive shaft gear G1 and the main shaft gear G2 do not become insufficiently lubricated, and each gear G1, G2 The teeth are also prevented from being frictioned and worn, and the gears G1, G2 can be smoothly rotated over a long period of time. As a result, the heat generation of these gears G1 and G2 can be suppressed, the deterioration of the gear lubrication grease can be prevented, and the grease can contribute to the lubrication of the drive shaft gear G1 and the main shaft gear G2 over a long period of time. .

  The flange upper surface 27c and the drive shaft gear G1 are preferably positioned as close to each other as possible. Specifically, the workability during assembly of the rotary blade unit U1 and the swinging of the drive shaft gear G1 and the main shaft gear G2 In consideration of the above, it is preferable to set the distance L1 between the two at least 5 mm or less. At that time, the interval L1 may be set so that the peripheral edge portion of the flange upper surface 27c and the drive shaft gear G1 are positioned as close as possible.

  Further, in this embodiment, the main shaft 8 is provided with the flange 27, and the flange upper surface 27c of the flange 27 is set to a distance L6 from the facing portion 40t of the case 40 (as an example, set to about 1 mm) in the axial direction. Therefore, the gear lubrication grease is more easily drawn into the drive shaft gear G1. In this case, when the facing portion 40t of the case 40 is positioned above the flange upper surface 27c of the flange 27 in the axial direction, the gear lubricating grease travels through the gap between the outer peripheral portion 27a of the flange 27 and the inner wall 40s of the case 40. Therefore, the flange upper surface 27c needs to be positioned above the facing portion 40t of the case 40 in the axial direction. At this time, if the protruding height L6 in the axial direction with respect to the facing portion 40t of the flange upper surface 27c is a positive dimension (greater than 0), the specific dimension is the above-described dimension (about 1 mm). Is not particularly limited, but is preferably set to 1 mm or more.

  As described above, the gear-lubricating grease actively flows in the space S during the use of the mower, that is, during the operation of the rotary blade unit U1, and repeats circulation with little contact with the slinger upper surface 25c. Therefore, it is possible to reliably prevent the gear lubrication grease from leaking into (intruding into) the rotary blade side bearing 2 and to keep the drive shaft gear G1 and the main shaft gear G2 in a good lubrication state for a long period of time. Can do. At this time, since the gear lubrication grease repeatedly circulates in the space S, the heat generation of the gear lubrication grease due to stirring and shearing can be reduced, and the grease deterioration can be effectively suppressed. This can contribute to the lubrication of the drive shaft gear G1 and the main shaft gear G2.

  Further, in the present embodiment, the flange 27 is provided by reducing the distance between the inner wall 40s as much as possible without contacting the inner wall 40s of the case 40 (as an example, the distance between the outer peripheral portion 27a and the inner wall 40s (FIG. 1 ( The distance L2) shown in b) is set to about 0.1 mm), so that the thickness of the flange 27 (distance L5 shown in the figure (5 mm as an example)) is between the outer peripheral portion 27a and the inner wall 40s. The air layer Ly can be formed at a corresponding depth. In this case, the ratio of the depth (corresponding to the thickness L5 of the flange 27) and the width (corresponding to the distance L2 between the outer peripheral portion 27a and the inner wall 40s) of the air layer Ly is sufficiently large (for example, L5 / L2 = 50). Therefore, an air flow in the rotation direction is generated in the air layer Ly as the main shaft 8 rotates.

  For this reason, even when the gear lubrication grease repeatedly circulates in the space S and the gear lubrication grease is softened and easily flows, the air flow of the air layer Ly described above becomes the air layer Ly. It is possible to block the intrusion of gear lubrication grease into the motor. That is, since the air flow in the air layer Ly performs the same effect as the seal (air seal effect), it is possible to effectively prevent the gear lubricating grease from entering the air layer Ly. As a result, the gear lubricating grease Can be reliably prevented from leaking (invading) into the rotary blade side bearing 2.

The ratio (L5 / L2) of the depth (L5) to the width (L2) of the air layer Ly is too small (for example, the width L2 of the air layer Ly, that is, the cross-sectional area is large). It is not possible to sufficiently exert the gear lubrication grease, and it is not possible to sufficiently prevent the gear lubrication grease from entering the air layer Ly. Therefore, the gear lubrication grease can be set as large as possible according to the space volume of the space S. preferable. That is, it is preferable to configure the flange 27 by setting the gap L2 between the outer peripheral portion 27a of the flange 27 and the inner wall 40s of the case 40 as narrow as possible and setting the thickness L5 of the flange 27 as large (long) as possible.
As an example, in the present embodiment, considering the air sealing effect, specifically, the effect of preventing the gear lubricating grease from entering the air layer Ly, as described above, the depth (with respect to the width (L2) of the air layer Ly ( The ratio (L5 / L2) of L5) is set to 50. In other words, the flange 27 is configured so that the ratio (L5 / L2) of the thickness L5 to the distance L2 between the outer peripheral portion 27a and the inner wall 40s is 50, and the flange 27 is positioned with respect to the main shaft 8. Yes.

  Further, as described above, the seal (not shown, which corresponds to the rubber seal 20 shown in FIG. 3B) located on the drive shaft gear G1 and main shaft gear G2 side (the upper side of FIG. 1B) includes Since neither the outer diameter part nor the inner diameter part is provided with a through hole (corresponding to the through hole 22h formed in the rubber seal 22 shown in FIG. 3B) for suppressing a pressure change inside the bearing, There is no inconvenience that the gear lubrication grease leaks (enters) into the rotary blade side bearing 2 from the through hole and is mixed with the bearing lubrication grease.

  As described above, according to the rotary blade unit U1 according to the present embodiment, the flange 27 is provided on the main shaft 8 so that the inside thereof (for example, the space S and the inside of the rotary blade side bearing 2) is enclosed. Leakage of grease to the outside can be reliably prevented. Thereby, the lubrication state of the rotary blade unit U1 is maintained well, and the wear of the drive shaft gear G1 and the main shaft gear G2 and the seizure of the rotary blade side bearing 2, the gear side bearing 4 and the drive shaft bearing 6 are prolonged. The cutting blade 32, which is a rotating member, can be stably rotated with a constant rotational accuracy over a long period of time without being generated.

Here, with respect to the mower according to the present embodiment, a predetermined test was performed and verified with respect to the leakage preventing effect of the grease enclosed in the mounted rotary blade unit U1. The test contents and test results will be described below.
In this test, two mowers (corresponding to the mower A shown in FIG. 4) are prepared as test machines, and one of the mowers has a rotary blade unit (see FIG. A rotary blade unit U1) shown in a) and (b) was mounted (hereinafter, the mower is referred to as the present machine). On the other hand, a conventional rotary blade unit (rotary blade unit U2 shown in FIG. 3A) not provided with the flange 27 is mounted on the other mower (hereinafter, the mower is referred to as a comparator). .

During the test, the present machine had a predetermined lubricant (Duplex EP No. 2 (hereinafter referred to as Kyodo Yushi Co., Ltd.) (hereinafter referred to as “Kyodou Yushi Co., Ltd.”) with respect to the inside of the rotary blade unit (space S shown in FIGS. Only 9.1 g of gear lubrication grease) was filled. In addition, this filling amount (9.1 g) corresponds to a volume amount of about 80% with respect to the space volume inside the rotary blade unit (space portion S).
On the other hand, the comparison machine was filled with 10.8 g of the same gear lubrication grease as the present machine. This filling amount (10.8 g) corresponds to a volume amount of about 80% with respect to the space volume inside the rotary blade unit (space portion S).

  In this case, the space volume inside the rotary blade unit (space portion S) is smaller by the volume of the flange 27 in the present machine than in the comparison machine. In this test, the volume of the flange 27 is set to about 2.3 cc, and the volume (2.3 cc) corresponds to about 2.1 g in terms of the weight of the gear lubricating grease.

  Of the two rolling bearings that support the main shaft of each rotary blade unit, the bearing is located on the cutting blade 32 side that is the rotary member (the rotary blade side bearing 2 shown in FIGS. 1A and 3A). As a ball bearing, the outer diameter of the bearing is set to 32 mm, the inner diameter of the bearing is set to 12 mm, the bearing width is set to 10 mm, and a contact type rubber seal is attached to seal the inside. The contact type rubber seal is not formed with a through hole (air hole) for suppressing (adjusting) the pressure change inside the bearing, and the inside of the bearing is kept almost completely sealed. Further, inside the bearing, as a lubricant, a thickening agent is lithium soap and a base oil is a mineral oil-based grease (Shell Albanian Grease S2 manufactured by Showa Shell Sekiyu KK) (hereinafter referred to as bearing lubricating grease). 4 g was enclosed.

  On the other hand, as a bearing (gear-side bearing 4 shown in FIGS. 1 (a) and 3 (a)) located on the drive shaft gear G1 and main shaft gear G2 side, the bearing outer diameter is 26 mm, the bearing inner diameter is 9 mm, and the bearing width. Was set to 8 mm, and a so-called open type (open type) deep groove ball bearing in which no sealing member for sealing the inside was provided was used. In this case, no lubricant was sealed inside the bearing, and the bearing was lubricated with the above-described gear lubrication grease (Duplex EP No. 2 manufactured by Kyodo Yushi Co., Ltd.).

  FIG. 2 (a) shows a test device for verifying the grease leakage prevention effect of the rotary blade unit mounted on the mower. Using the test device, the machine and the comparator are set under predetermined conditions. After operating at a predetermined speed (rotation speed of the cutting blade) for a predetermined time, the gear lubrication grease enclosed in the rotary blade unit and the bearing lubrication grease enclosed in the rolling bearing (rotary blade side bearing) By comparing the leakage state to the outside, we verified the grease leakage prevention effect of the rotary blade unit for these mowers.

  As shown in FIG. 2 (a), the test apparatus has a rectangular parallelepiped box shape, and angle steel is used as the frame material, and each surface portion surrounded by the frame material is an expanded metal. It is configured. Then, the test apparatus is fastened and fixed to the gantry with bolts, and the operation tube 30 and the operation handle 36 (see FIG. 4) of the mower are in the test apparatus so that the mower is suspended in the test apparatus. It was fixed with a string to the frame material.

  In the test, the atmospheric temperature of the mower (the machine and the comparator) under test is kept at room temperature, and in this state, the machine and the comparator are the longest at a speed of 8000 revolutions per minute. The operation was continued for 30 hours. At that time, fuel was supplied to the engine 34 (see FIG. 4) at a predetermined timing, and the present machine and the comparator were continuously operated. After that, remove the rotary blade unit from the machine and the comparator, and grease leaked from the inside of the rolling bearing (rotary blade side bearing) (bearing lubrication grease, or a mixture of bearing lubrication grease and gear lubrication grease (hereinafter referred to as These leaked greases were collectively referred to simply as “grease”) and collected with a spatula (small spoon), and the amount of leakage was measured and compared for the machine and the comparator. In this test, the operation of the mower (the present machine and the comparator) and the measurement of the amount of grease leakage were taken as one test cycle, and the test cycle was repeated twice, and the results were compared.

  FIG. 2 (b) shows the results of each test. As is apparent from FIG. 2, in the case of the comparator without the flange 27, the amount of grease leakage from the rolling bearing (rotating blade side bearing). At 10 hours before the operating time reached 30 hours, all became 4 g or more, and a larger amount of grease (more than 10 times) leaked from the amount enclosed in the bearing (about 0.4 g). That is, it was verified that the gear lubricating grease leaked (invaded) inside the bearing was mixed with the bearing lubricating grease and further leaked outside the bearing. In this case, the leaked grease reached the cutting blade, and the test was stopped when the operation time passed 10 hours.

On the other hand, in the case of the present machine provided with the flange 27, the amount of grease leakage from the rolling bearing (rotary blade side bearing) is 0.09 g and 0. 0 even after 30 hours of operation time. 13g, which is only 23% and 33% of the amount of bearing lubrication grease enclosed in the bearing (about 0.4g), and 2.3% and 3.3% of the grease leakage amount (4g or more) of the comparator It wasn't too much.
Further, the grease leakage amount relative to the gear lubricating grease filling amount in the rotary blade unit (space S) was only 1.0% and 1.4%.

  As described above, as in the rotary blade unit U1 according to the present embodiment, the flange 27 is provided on the main shaft 8 so that the grease (gear lubrication grease and bearing lubrication) enclosed in the interior (space S) of the rotary blade unit U1. It can be verified by the above test that the grease) can be surely prevented from leaking to the outside, and the cutting blade 32, which is a rotating member, can be stably rotated with a constant rotational accuracy over a long period of time. It was.

It is a figure which shows the structural example of the rotary blade unit which concerns on one Embodiment of this invention, Comprising: (a) is sectional drawing, (b) demonstrates the magnitude | size of a flange, and the space | interval of a flange and each member. The principal part expanded sectional view for this. It is a figure for demonstrating the test about the leakage prevention effect of the grease enclosed inside the rotary blade unit mounted in the mower, Comprising: (a) is a figure which shows the example of whole structure of a test apparatus, (b) FIG. 6 is a diagram showing test results for the present machine and the comparator. It is a figure which shows the structural example of the conventional rotary blade unit, (a) is sectional drawing, (b) is sectional drawing which shows the structural example of a rotary blade side bearing. The perspective view which shows the example of whole structure of the conventional mower.

Explanation of symbols

2 Rotary blade side bearing 4 Gear side bearing 8 Main shaft 27 Flange 27a Flange outer peripheral portion 27c Flange upper surface 32 Cutting blade 34 Engine 38 Drive shaft 40 Case 40t Opposing portion G1 Drive shaft gear G2 Main shaft gear L1 Flange upper surface-drive shaft gear distance L2 Flange outer peripheral portion-case inner wall distance L3 Case inner wall diameter L33 Flange outer diameter L5 Flange thickness L6 Flange upper surface protruding height S Space 40s Case inner wall Ly Air layer U1 Rotary blade unit

Claims (5)

A main shaft extending in a predetermined direction, a plurality of bearings rotatably supporting the main shaft, and a driving shaft and a main shaft for transmitting the rotational force of the driving shaft rotated by the driving device to the main shaft; Rotating member support unit comprising at least one set of gears which are respectively provided on one end side of the shaft and meshing with each other, a rotating member attached to the other end side of the main shaft, and a case for housing the main shaft, the bearing and the gear Because
Lubricant for lubricating the gear is sealed in the unit, and the main shaft is provided with a bearing arranged to circulate the lubricant in the unit and at least closest to the rotating member. A flange for preventing entry of foreign matter into the interior is provided, and the flange is configured so that the predetermined part of the main shaft is enlarged toward the inner wall of the case and the diameter of the main shaft is larger than that of other parts. A rotating member support unit, characterized in that the rotating member support unit has a structure in which the outer peripheral portion is arranged continuously over the circumference and is opposed to the inner wall of the case at a predetermined interval.   The case is provided with a facing portion on the inner wall facing the gear on one end side of the drive shaft at a predetermined interval, and the flange has a predetermined end surface on the gear side in the axial direction than the facing portion. The rotating member support unit according to claim 1, wherein the rotating member support unit is positioned so as to protrude by a height.   3. The rotating member according to claim 1, wherein a thickness ratio in the axial direction of the flange and a dimensional ratio of a facing distance between the flange outer peripheral portion and the case inner wall are set to be larger than 20: 1. Support unit.   The case is characterized in that the diameter of the inner wall of the case is set larger than the outer diameters of the flange, a gear provided on one end of the main shaft, and a bearing disposed closest to the gear. The rotating member support unit according to claim 1.   The rotating member support unit according to any one of claims 1 to 4, wherein a cutting blade is attached to the main shaft as a rotating member for cutting away vegetation growing on the ground surface from the vicinity of the root.

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