JP2008164169A - Rotating member support unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating member support unit capable of continuing to rotate a rotating member stably with constant rotating accuracy over a long period of time while preventing a leakage of filled grease by providing a slinger always in a static state to a bearing for journaling the rotating member. <P>SOLUTION: The rotating member support unit comprises an erected spindle 8; bearings 2, 4 provided with static rings and rotating rings to support the spindle rotatably; gears G1, G2 provided on one end side of a driving shaft and the spindle; the rotating member 32 mounted to the other end side of the spindle; and a case 40 holding the spindle, the bearings and the gear. At least the bearing arranged closest to the rotating member is provided with the annular slinger 25 in close contact with or in proximity to a gear-side side face 12c of the static ring 12 to always maintain the static state to prevent foreign matter from intruding inside. An inner peripheral surface 25a is positioned facing the spindle with a predetermined space L1 and positioned not in contact with each of the rotating ring 10 and gear. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

FIGS. 9A and 9B show an example of the 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.

  The rotary blade unit U2 includes a main shaft 8 extending in a predetermined direction and two rolling bearings (hereinafter referred to as the rotary blade side bearing 2 (FIG. 9B)) that rotatably support the main shaft 8. In order to transmit the rotational force of the drive shaft 38 to the main shaft 8 (on the lower side bearing) and the gear side bearing 4 (upper bearing in the figure). A pair of gears (referred to as drive shaft gear G1 (right side gear in the figure) and main shaft gear G2 (left side gear in the figure)) provided on the left end side and the upper end side in FIG. And a rotatable rotating member (cutting blade) 32 attached to the other end side of the main shaft 8 (lower end side in the figure).

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. 9B). Further, the operation tube 30 is provided with a protective cover 42 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.

  Further, for example, as the rotary blade side bearing 2, a sealed ball bearing in which a contact type rubber seal (not shown) is interposed between the inner and outer rings and balls are incorporated between the inner and outer rings as rolling elements is applied. In order to lubricate the rotary blade side bearing 2, as an example, a grease composed of lithium soap as a thickener and mineral oil as a base oil (hereinafter referred to as bearing lubrication grease) is enclosed inside the bearing. ing. In this case, as an example, the rubber seal (not shown) has an outer diameter portion fixed to the outer ring of the rotary blade side bearing 2 and an inner diameter portion (lip portion) formed on the inner ring of the rotary blade side bearing 2. It is positioned so as to be in sliding contact with the seal groove (not shown).

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 only passed through a rubber seal (a seal (not shown) located on the gears G1 and G2 side). And is always in contact with the 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 accumulates on the outer surface (surface on the gears G1, G2 side) of a rubber seal (not shown) located on the gears G1, G2 side by its own weight, and presses the seals. In addition, the outer surface of the rubber seal (not shown) in which 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. A large amount is deposited on the (gear G1, G2 side surface), and the seal is pressed.

If the rubber seal (not shown) is continuously pressed by the gear lubrication grease, as a result, the gear lubrication grease is transferred from the sliding contact portion between the lip portion of the seal and the seal groove of the rotary blade side bearing 2 to the rotary blade side. Leakage (intrusion) may occur inside the bearing 2.
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 into the bearing progresses as described above, the amount of grease in the rotary blade side bearing 2 increases from a set value, and stirring and shearing are activated, It may soften. When such softening of the grease occurs, the lip portion of the rubber seal (seal (not shown) located on the cutting blade 32 side) of the rotary blade side bearing 2 and the seal groove (not shown) of the rotary blade side bearing 2 are generated. The grease may leak out of the rotary blade side bearing 2 from a sliding contact portion or an air hole (not shown) provided in the seal. In this case, for example, the leaked grease adheres to the cutting blade 32 (state of the grease Gb in FIG. 9B), which may deteriorate the rotation 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. Applying a grease harder than the grease No. 2 to suppress the softening caused by stirring or shearing the grease, the grease is attached 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 to solve such a problem, and the object thereof is to provide a slinger that is always kept stationary with respect to a rolling bearing that pivotally supports a rotating member (for example, a cutting blade). An object of the present invention is to provide a rotating member support unit capable of preventing the grease enclosed inside from leaking to the outside and continuously rotating the rotating member with a constant rotation accuracy over a long period of time. .

In order to achieve such an object, a rotating member support unit according to the present invention includes a main shaft extending in a predetermined direction, and a stationary wheel and a rotating wheel arranged to face each other so as to be relatively rotatable. A plurality of rolling bearings that rotatably support the main shaft and the drive shaft and one end side of the main shaft that are provided on one end side of the main shaft so as to transmit the rotational force of the drive shaft rotated by the driving device to mesh with each other. At least one set of gears, a rotating member attached to the other end of the main shaft, and a case for housing the main shaft, a rolling bearing, and the gears are provided.
In such a rotating member support unit, at least the rolling bearing disposed closest to the rotating member has an annular slinger closely attached to the side surface of the stationary ring on the gear side in order to prevent foreign matter from entering the rolling bearing. Proximity is provided. In this case, the slinger is always kept stationary, and is positioned so as to face the main shaft at a predetermined interval, and is positioned so that neither the rotating wheel of the rolling bearing nor the gear is in contact. ing.

As an example, in the rolling bearing disposed closest to the rotating member, at least a pair of sealing members forming an annular shape for sealing the inside of the rolling bearing are interposed between the stationary wheel and the rotating wheel with the rolling element interposed therebetween. In a state where the slinger is fixed to the inner wall of the case, the side surface on the rolling bearing side is brought into close contact with the side surface on the gear side of the stationary ring, and is opposed to the sealing member with a predetermined interval. What is necessary is just to make it the structure made to.
Note that 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, by providing the rolling bearing that pivotally supports the rotating member (for example, the cutting blade) with the slinger configured to be stationary at all times, the grease sealed inside can be leaked to the outside. While being able to prevent, the said rotation member can be continuously rotated stably with a fixed 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 rotary member support that supports various rotary members, such as a mower, a brush cutter, a lawn mower, or an electric tool, with a main shaft extending in a predetermined direction and rotating together with the main shaft. In the following, a rotary blade unit used in a mower attached to a main shaft as a rotary member is used as a rotary member for cutting a vegetation growing on the ground surface from near the root. Assuming it as an example, the configuration of the rotary blade unit will be described. 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. 9A) 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. 9B) 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.

“First Embodiment”
1A and 1B show a rotary blade unit U1 (rotary member support unit) of a mower according to the first embodiment of the present invention. The rotary blade unit U1 has a predetermined direction. The main shaft 8 extending to the shaft, a plurality of rolling bearings 2 and 4 that rotatably support the main shaft 8, and the rotational force of the drive shaft 38 rotated by the drive device (see the engine 34 (see FIG. 9A)). At least one set of gears G1, G2 provided on one end side (the left end side and the 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 of the main shaft 8 (the lower end side in 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 change the direction of the rotational force generated by the engine 34 (FIG. 9A) and reduce the speed of the cutting blade attached to the main shaft 8. 32 is rotated to perform a so-called transmission function.

  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, as shown in FIG. 1B, the rotary blade side bearing 2 is arranged so that a rotating wheel (hereinafter referred to as an inner ring) 10 and a stationary wheel (hereinafter referred to as an outer ring) 12 face each other so as to be relatively rotatable. A plurality of rolling elements (balls) 14 are incorporated between the inner ring 10 and the outer ring 12 so as to be able to roll. In this case, the rolling elements (balls) 14 are rotatably held one by one in a pocket formed in a ring-shaped cage (for example, a corrugated mating cage) 16 and the inner ring 10 and It is incorporated between the raceway surfaces of the outer ring 12. Thereby, each rolling element (ball) 14 can roll between the inner and outer rings 10 and 12 (between the raceway surfaces) without the rolling surfaces being in contact with each other, and as a result, the respective rolling elements. It is possible to prevent an increase in rotational resistance or seizure caused by friction between the (balls) 14 coming into contact with each other.

  Note that the types and sizes of the rotary blade side bearing 2, the rolling elements (balls) 14, and the cage 16 are arbitrarily set according to the size of the mower, the rotational output of the driving device (engine), and the like. Therefore, there is no particular limitation here. For example, as the rotary blade side bearing 2, in addition to the 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. 1A and 1B, rollers such as cylindrical rollers, tapered rollers, and spherical rollers (rubber rollers) may be applied as the rolling element 14. Further, as the retainer 2c, a so-called corrugated retainer as shown in FIGS. 1A and 1B, a crown retainer, a cage retainer, or the like may be applied.

  However, the size of the rotary blade side bearing 2 is such that the diameter difference (radius value) between the diameter of the main shaft 8 (specifically, the large diameter portion 8a) and the inner diameter of the inner ring 10 is H1 (FIG. 1B). When the distance difference (radius value) between the outer diameter of the seal shoulder 20g and 22g and the inner diameter of the inner ring 10 is H2 (distance H2 shown in the figure), The distance H1 is set to the same dimension as the distance H2 or smaller (H2 ≧ H1), and is set to a dimension (H1> H2 / 2) larger than the intermediate distance (radius value) of the distance H2 (ie, H2> H2 / 2). , H2 ≧ H1> H2 / 2). The seal grooves 20g and 22g are formed at the outer peripheral end portion of the inner ring 10 in order to make slidable contact with seal lips 20l and 22l of seals 20 and 22, which will be described later.

  For example, when the distance H1 is larger than the distance H2 (H1> H2), the peripheral speed of the main shaft 8 is increased, and there is a possibility that grease (such as gear lubrication grease described later) softened excessively. In addition, the unbalance amount of the grease in the space S may increase, and vibrations of the main shaft 8 and the rotary blade side bearing 2 may be increased. By setting the relationship H2 ≧ H1, such inconvenience is caused. Can be avoided. Further, when the distance H1 is smaller than the intermediate distance of the distance H2 (H1 <H2 / 2), the side surface 10c on the gears G1, G2 side of the inner ring 10 (the upper surface in FIG. 1B) and the main shaft 8 (specifically In this case, the contact plane with the stepped portion 8g) may be reduced and the rotary blade side bearing 2 may be inserted with an inclination. By setting the relationship H1> H2 / 2, such inconvenience is avoided. be able to.

  Further, in the rotary blade side bearing 2, a rolling element (ball) 14 is sandwiched between the inner ring 10 and the outer ring 12, and the rotary blade side bearing is placed on both sides (the upper side and the lower side in FIG. 1B). Sealing members (contact type rubber seals (hereinafter simply referred to as “seal”)) 20 and 22 for sealing 2 are provided. By providing the seals 20 and 22 in this way, foreign matters (for example, shaved wood scraps, muddy water, and dust) enter 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.

  In the configuration shown in FIG. 1B, as an example, the seals 20 and 22 are made of various types of annular core bars 20c and 22c formed by press working or the like so that the cross section is L-shaped. Are connected by an elastic material (for example, a resin material such as rubber or plastic). Seal lips 20l and 22l made of such an elastic material are formed on the inner diameter portions of the seals 20 and 22. The outer diameter portions of the seals 20 and 22 are fixed to mounting grooves formed on the outer ring 12 of the rotary blade side bearing 2, and the inner diameter portions (seal lips 20 l and 22 l) thereof are inner rings of the rotary blade side bearing 2. 10 is positioned so as to be in sliding contact with the seal grooves 20g and 22g formed in the base plate 10.

  However, the shape of the seals 20 and 22 is not particularly limited to the shape described above. For example, the core metal may be configured as a flat annular flat plate, or the entire core metal may be connected to the elastic material. Good. Further, a plurality of (for example, three) seal lips may be formed. When the core bars 20c and 22 are connected to various elastic materials, various methods such as adhesion, caulking, coating, and injection molding can be arbitrarily selected and used as the connection method.

The size of the seals 20 and 22 (for example, the width (the distance in the horizontal direction in FIG. 1B) and the thickness (the distance in the vertical direction in FIG. 1)) is, for example, the size of the rotary blade side bearing 2. Since it is arbitrarily set according to the above, it is not particularly limited here. However, the thickness of the seals 20 and 22 (the distance in the vertical direction in FIG. 1B) is such that the seals 20 and 22 are the side surfaces of the inner ring 10 of the rotary blade side bearing 2 and the gears G1 and G2 side of the outer ring 12 (see FIG. It is preferable that the thickness is such that the inner surface of the bearing 2 is recessed more than the upper surface).
As an example, in the present embodiment, the thickness of the seals 20 and 22 is set so that the depth of the recesses from the side surfaces of the inner and outer rings 10 and 12 is about 0.25 mm, and the seals 20 and 22 The case where it positions between the inner and outer rings 10 and 12 is assumed.

  Here, in this embodiment, as an example, the contact-type seals 20 and 22 as shown in FIG. 1B are applied to the sealing member. For example, the outer diameter portion of the sealing member is an outer ring. 12 is a non-contact type seal that is fixed to the mounting groove 12 and has an inner diameter portion that does not contact the seal groove of the inner ring 10 (for example, a whole or a part of a steel plate core is made of various elastic materials (for example, rubber, plastic, etc. Or a non-contact type shield (for example, a shield formed by press molding from a thin metal plate such as a stainless steel plate or an iron plate) may be applied.

  Further, of the two seals 20 and 22, the seal 22 positioned on the cutting blade 32 side (the lower side in FIG. 1B) which is a rotating member has a through hole 22h for suppressing a pressure change inside the bearing. Is provided. In this case, the through hole 22h penetrates at least the outer diameter portion of the seal 22 from the inner side to the outer side of the seal 22 (from the upper side to the lower side in FIG. 1B). Is formed.

  In the configuration shown in FIG. 1B, the through-hole 22h is, for example, a portion consisting only of a connection of an outer diameter portion of the seal 22 by an elastic material (for example, a resin material such as rubber or plastic), that is, a cored bar 22c. It is formed in the site | part only of the elastic material which does not contain. In this way, by forming the through hole 22h only in the elastic material, the through hole 22h is not normally open, and the inside of the rotary blade side bearing 2 is pressurized or depressurized. Only when the seal 22 is elastically deformed, it can be configured as a so-called air valve that is in an open state and discharges the inside air of the bearing 2 or allows the outside air of the bearing 2 to flow in.

  Note that the shape, size, position, number, and the like of the through holes 22h are not particularly limited here because they are arbitrarily set according to the shape, size, and the like of the seal 22, for example. For example, the through hole 22h is not formed on the outer diameter portion of the seal 22, or may be formed on the inner diameter portion (specifically, the seal lip 22l that is in sliding contact with the wall portion of the seal groove) in addition to the outer diameter portion. Good. Further, for example, only one through hole 22h may be formed in the outer diameter portion of the seal 22, or a plurality of through holes 22h may be formed at predetermined intervals along the circumferential direction.

  On the other hand, of the two seals 20 and 22, the seal 20 positioned on the drive shaft gear G1 and main shaft gear G2 side (the upper side in FIG. 1B) has both an outer diameter portion and an inner diameter portion. A through hole for suppressing a pressure change inside the bearing, that is, a through hole corresponding to the through hole 22h formed in the above-described seal 22 is not provided.

  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 in FIG. 1B) are completely sealed by the seal 20 while the cutting blade 32 is inside. The side (the lower side in FIG. 1B) is not completely sealed because the seal 22 has a through hole 22h. That is, the inside of the rotary blade side bearing 2 is openable to the outside of the bearing through the through hole 22h of the seal 22 on the cutting blade 32 side (lower side in FIG. 1B). Inside air can be discharged from the through hole 22h to the outside of the bearing, and outside air can be allowed to flow into the bearing.

Thereby, for example, when the inside of the bearing is pressurized by the rotation of the rotary blade side bearing 2, the seal 22 (connection portion by the elastic material) is elastically deformed to open the through hole 22h, and the through hole 22h is opened. By discharging the inside air, it is possible to suppress an increase in the pressure inside the bearing and to keep the internal pressure of the bearing constant. As a result, for example, the seal lips 20l and 22l of the seals 20 and 22 are not separated from the wall portion of the seal groove due to an increase in bearing internal pressure.
On the other hand, for example, when the inside of the bearing is depressurized by stopping the rotary blade side bearing 2, the through hole 22h is similarly opened, and the pressure inside the bearing is reduced by flowing in the outside air from the through hole 22h. This can be suppressed and the internal pressure of the bearing can always be kept constant. As a result, for example, the seal lips 20l and 22l of the seals 20 and 22 are not attracted to the wall portion of the seal groove due to a decrease in the bearing internal pressure, and the rotational torque of the rotary blade side bearing 2 does not increase.

Note that, as in this embodiment, a mower or the like equipped with the engine 34 (FIG. 9A) as a driving device has a large driving force (rotational output). Even if the rotational torque increases, the rotational accuracy of the cutting blade 32 is hardly affected, and deterioration of the rotational accuracy of the cutting blade 32 due to the increase of the rotational torque can be minimized. For this reason, for example, grease (such as bearing lubrication grease to be described later) leaks from the through hole 22h of the seal 22 on the cutting blade 32 side (lower side in FIG. 1B) to the outside of the rotary blade side bearing 2, and the leakage occurs. In consideration of inconvenience caused when grease adheres to the cutting blade 32, the seal 22 is not formed with the through hole 22h, and the seal 22 is connected to the drive shaft gear G1 and the main shaft gear G2 (upper side of FIG. 1 (b)). A configuration similar to that of the seal 20 of FIG.
Thus, the rotary blade side bearing 2 has a configuration in which the inside is completely sealed, and the grease (such as the bearing lubricating grease) sealed in the bearing can be reliably prevented from leaking to the outside of the bearing.

  In addition to the seals 20 and 22, the rotary blade side bearing 2, which is a rolling bearing disposed closest to the rotary member (cutting blade 32), has foreign matter (for example, gear lubrication grease, dust, etc.) inside the bearing. ) Is provided in close contact with the side surface 12c of the outer ring 12 on the drive shaft gear G1 and main shaft gear G2 side (upper side in FIG. 1B). The slinger 25 is positioned with its inner peripheral surface 25a facing the main shaft 8 with a predetermined distance (distance L1 shown in FIG. 1B), and the inner ring 10 and the gear G1 of the rotary blade side bearing 2. , G2 are positioned so as to be non-contact with each other, so that they are always kept stationary.

  As an example, in the configuration shown in FIG. 1B, the outer diameter is approximately the same as the diameter of the inner wall of the case 40 (wall portion forming a predetermined space S surrounding the drive shaft gear G1 and the main shaft gear G2) 40s. The slinger 25 is configured to have a cylindrical shape whose inner diameter is set to be slightly larger than the diameter of the large diameter portion 8a of the main shaft 8. In this case, since the outer diameter and the inner diameter of the slinger 25 are set to the same diameter over the entire length (distance from the upper end to the lower end of FIG. 1B), the extending direction of the main shaft 8 (vertical) The shape of the cross section (vertical cross section) with respect to the direction (vertical direction in the figure) forms a rectangle (for example, a rectangle in the figure).

  The slinger 25 is fixed (for example, interference fit) to the inner wall 40s of the case 40. In this state, the side surface of the rotary blade side bearing 2 (the lower surface of FIGS. 1A and 1B (hereinafter referred to as the slinger lower surface). 25b) is closely attached to the side surface (upper surface in the figure) 12c of the outer ring 12 on the side of the gears G1, G2. Similarly, in this state, the slinger 25 has the slinger lower surface 25b opposed to the seal 20 with a predetermined interval.

  Thereby, even if the main shaft 8, the inner ring 10, the drive shaft gear G1 and the main shaft gear G2 rotate, the slinger 25 remains in a non-rotating state (that is, a stationary state) without rotating with them. The inner peripheral surface 25a can be opposed to the outer peripheral surface 8s of the main shaft 8 (large diameter portion 8a) in a rotating state with a predetermined interval (distance L1 shown in FIG. 1B). Further, the slinger 25 has an inner peripheral surface 25a and a side surface on the side of the gears G1, G2 (upper surfaces of FIGS. 1A and 1B (hereinafter referred to as slinger upper surfaces)) 25c, the inner ring 10 in a rotating state, and the drive. Both the shaft gear G1 and the main shaft gear G2 can be opposed to each other with a predetermined interval.

  The attachment method of the slinger 25 is not particularly limited to the interference fitting (fitting) as described above. For example, an adhesive member such as an adhesive is attached to the case according to the size, shape, and material of the slinger 25. The inner wall 40s of the case 40 may be applied and bonded, or may be attached to the inner wall 40s of the case 40 by joining by welding or the like, or fastening by a fastening member (screw or pin). Various methods may be attached in combination.

  In the configuration shown in FIG. 1B, as an example, the slinger lower surface 25b is in close contact with the side surface 12c of the outer ring 12 in a state where the slinger 25 is fixed (tightened) to the inner wall 40s of the case 40. The slinger 25 is fixed to the inner wall 40 s (for example, interference fit (fitting), joined (adhesion or welding), fastened, etc.), and the slinger 25 is not brought into close contact with the side surface 12 c of the outer ring 12 and has a predetermined They may be positioned close to each other with a gap.

Here, the size of the slinger 25 may be arbitrarily set according to the shape of the main shaft 8 and the case 40, the size of the rotary blade side bearing 2, and the like, but the main shaft 8, the inner ring 10, the drive shaft gear G1. It is preferable that the main shaft 8, the inner ring 10, and the gears G 1, G 2 are set to the maximum size within a range in which the main shaft gear G 2 and the gears G 1, G 2 can smoothly rotate without contacting any of the main shaft gear G 2 and the seal 20. In other words, the slinger 25 has an interval between the inner peripheral surface 25a and the outer peripheral surface 8s of the main shaft 8 (large diameter portion 8a) (distance L1 shown in FIG. 1B), as well as the slinger upper surface 25c and the outer peripheral surface. It is preferable that the distance between the surface and the drive shaft gear G1 is set to a predetermined size so as to be as small as possible.
However, the inner diameter of the case 40 is such that when the rotary blade unit U1 is assembled, the main shaft 8, the rotary blade side bearing 2, the gear side bearing 4, the drive shaft gear G1, and the main shaft gear G2 that are rotating bodies are placed below the case 40. In consideration of inserting from the above, it is necessary to set the size larger than the maximum diameter size of these rotating bodies.

  In the configuration shown in FIG. 1A, 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 the figure)). When setting the size of 25, it is only necessary to consider making the intervals between the slinger upper surface 25c and the outer peripheral surface and the drive shaft gear G1 as small 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. The size of the slinger 25 may be set so that the distance between the slinger upper surface 25c and the main shaft gear G2 is as small as possible.

  As an example, in the present embodiment, the distance between the inner peripheral surface 25a and the outer peripheral surface 8s of the main shaft 8 (large diameter portion 8a) (distance L1 shown in FIG. 1B) is about 0.1 mm, and the slinger upper surface 25c It is assumed that the inner and outer diameter dimensions of the slinger 25 are set so that the distance from the drive shaft gear G1 is about 2 mm, and the thickness (distance L3 shown in the figure) is set to about 5 mm. Further, since the slinger 25 is positioned so that the slinger lower surface 25b is substantially flush with the side surface 12c of the outer ring 12 of the rotary blade side bearing 2, the distance between the slinger lower surface 25b and the seal 20 (FIG. 1B). The distance L2) shown in FIG. 2 is substantially equal to the depth of the recess from the side surface 12c of the outer ring 12, and is about 0.25 mm.

  Since the seal 20 does not rotate with the main shaft 8, the inner ring 10, the drive shaft gear G1, and the main shaft gear G2 similarly to the slinger 25, the slinger 25 is in contact with the seal 20. It may be. In this case, the slinger 25 may be configured by setting the thickness L3 to a predetermined dimension that allows the slinger lower surface 25b to contact the seal 20. Similarly, the slinger 25 may have a shape in which the slinger lower surface 25b can come into contact with the seal 20 (for example, a shape partially protruding toward the seal 20).

The shape of the slinger 25 is a shape that can be attached to the inner wall 40s of the case 40 with the slinger lower surface 25b in close contact with the side surface 12c of the outer ring 12, and the inner peripheral surface 25a and the main shaft 8 (large diameter portion 8a). There is no particular limitation as long as the distance L1 between the outer peripheral surface 8s and the distance between the slinger upper surface 25c and the drive shaft gear G1 can be made as small as possible, and it is arbitrary depending on the shape of the main shaft 8 and the case 40, etc. The shape may be as follows.
As in the case of setting the size of the slinger 25 described above, in the configuration shown in FIG. 1A, when setting the shape of the slinger 25, the distance from the drive shaft gear G1 should be as small as possible. You should consider it. Similarly, when the main shaft gear G2 is positioned lower than the drive shaft gear G1 in the vertical direction, the shape of the slinger 25 may be such that the distance between the slinger upper surface 25c and the main shaft gear G2 is as small as possible. .

  Further, the number of slinger 25 is not limited to one as shown in FIGS. 1A and 1B, and may be two or more. For example, the thickness of the slinger 25 (distance L3 shown in FIG. 1 (b)) is approximately half of the configuration shown in the figure (2.5 mm as an example), and the two slinger 25 are closely contacted and overlapped. Alternatively, a slinger assembly having a multilayer structure or a multi-layer structure arranged concentrically at predetermined intervals may be used.

Here, in the above-described embodiment, the material of the slinger 25 is not particularly mentioned. However, the slinger 25 can be attached to the inner wall 40s of the case 40 with the slinger lower surface 25b in close contact with the side surface 12c of the outer ring 12. There is no particular limitation as long as it is present, and any material may be used depending on the material of the main shaft 8 and the case 40. For example, the slinger 25 may be composed of various resins such as nylon monomer, polyethylene resin, and polypropylene resin, and various elastic materials such as styrene-based and olefin-based thermoplastic elastomers, or various metal-based materials. The slinger 25 may be made of a material.
However, in consideration of lubrication for the rotary blade unit U1, it is preferable to apply various resins, elastic materials, and metal-based 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. 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 50% or approximately 80%. ing.

  If the amount of filling (encapsulation) of the gear lubrication grease is too large, the softening of the grease is promoted by heat generated by stirring. End up. For this reason, it is preferable to fill (enclose) in an amount that is approximately 30 to 90% of the space volume of the space S, and further to be filled (enclose) in an amount that is approximately 50 to 80%. ). In this case, the space portion S is not mounted on the slinger 25 (FIG. 1A) as in the conventional rotary blade unit U2 (FIG. 9B) by an amount corresponding to the volume of the slinger 25. It becomes smaller than the case of.

  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 is continuously stirred and sheared in the space S by its own weight, and the vibration caused by the rotation of the main shaft 8 and the main shaft gear G2 while the driving shaft 38 and the driving shaft gear G1 rotate. The gear lubricating grease that has been repeatedly stirred and sheared as described above rises in temperature, and is softened and thermally expanded.

At this time, the pressure (internal pressure) inside the rotary blade unit U1 (space part S) rises, so the rotary blade unit U1 against the internal air of the rotary blade unit U1 and the gear lubrication grease sealed in the space part S. A pressing force toward the outside, specifically, a pressing force on the inner wall 40s of the case 40 and the slinger 25 acts, and the gear lubricating grease falls on the slinger upper surface 25c and comes into contact.
In this state, the slinger 25 is stationary, but on the other hand, the main shaft 8 is rotating, so that the centrifugal force generated by the rotation of the main shaft 8 acts on the gear lubricating grease in contact with the slinger upper surface 25c.

  The gear lubrication grease to which the centrifugal force is applied moves above the space portion S through the inner wall 40s of the case 40, the surface of the drive shaft gear G1, and the surface of the main shaft gear G2 by the centrifugal force. Then, after the gear lubricating grease reaches the vicinity of the main shaft 8, it again falls and contacts the slinger upper surface 25c due to its own weight and vibration caused by the rotation. As a result, the gear lubricating grease is circulated in the space S.

  In the present embodiment, the slinger 25 is provided without making contact with the drive shaft gear G1 and the distance between the drive shaft gear G1 is reduced as much as possible (as an example, the distance between the slinger upper surface 25c and the drive shaft gear G1 is about 2 mm). Therefore, the gear lubricating grease can be easily drawn into the drive shaft gear G1. 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. .

  As described above, the gear-lubricating grease actively flows in the space S and repeats circulation when the mower is in use, that is, when the rotary blade unit U1 is in operation. For this reason, the gear lubrication grease does not stay (deposit) on the slinger upper surface 25c and eventually the outer surface of the seal 20 (the surface on the side of the drive shaft gear G1 and the main shaft gear G2) and does not press the seal 20. As a result, it is possible to prevent the gear lubricating grease from leaking (invading) into the rotary blade side bearing 2.

  In the present embodiment, the slinger 25 is provided with the space between the outer peripheral surface 8s as narrow as possible without contacting the outer peripheral surface 8s of the main shaft 8 (large diameter portion 8a) (as an example, the inner peripheral surface 25a By setting the distance from the outer peripheral surface 8s (the distance L1 shown in FIG. 1B to about 0.1 mm), the thickness of the slinger 25 between the inner peripheral surface 25a and the outer peripheral surface 8s (the same figure). The air layer Ly can be formed at a depth corresponding to the distance L3 (5 mm as an example) shown in FIG. In this case, the ratio of the depth (corresponding to the thickness L3 of the slinger 25) and the width (corresponding to the distance L1 between the inner peripheral surface 25a and the outer peripheral surface 8s) of the air layer Ly is sufficiently large (for example, L3 / L1 = 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 a pressing force is applied to the slinger 25 due to an increase in the internal pressure of the rotary blade unit U1, the pressing force is loaded by the air flow of the air layer Ly, that is, by the air flow of the air layer Ly. Thus, stress capable of resisting the pressing force can be generated, and the gear lubricating grease can be effectively prevented from entering the air layer Ly. Even when the gear lubrication grease is softened and easily flows as described above, if the air flow in the air layer Ly is longitudinally cut, the gear lubrication grease after the longitudinal cut will be the seal lip of the seal 20. There is no pressing force enough to slip through the sliding contact portion between 20l and the seal groove of the inner ring 10.

  As a result, it is possible to reliably prevent the gear lubricating grease from leaking into (intruding into) the rotary blade side bearing 2, and effectively preventing the gear lubricating grease from leaking (outflowing) to the outside of the rotary blade unit U1. can do. As a result, since the gear lubrication grease does not leak (outflow), the gear lubrication grease can always be kept at an appropriate amount. Therefore, the drive shaft gear G1 and the main shaft gear G2 do not become insufficiently lubricated, and the teeth of the gears G1, G2 are also prevented from being frictioned and worn (damaged) with each other. It can be rotated smoothly over the range. Further, since leakage (outflow) of the gear lubrication grease to the outside of the unit is prevented, contamination to the surrounding environment (such as vegetation and soil) can be more effectively prevented.

  If the ratio (L3 / L1) of the depth (L3) to the width (L1) of the air layer Ly is too small, the pressing force due to the increase in the internal pressure of the rotary blade unit U1 can be sufficiently loaded by the air flow. Therefore, it is not possible to sufficiently prevent the gear lubricating grease from entering the air layer Ly. Therefore, it is preferable to set the gear lubricating grease as large as possible according to the space volume of the space S. Specifically, the ratio (L3 / L1) of the depth (L3) to the width (L1) of the air layer Ly is preferably set to 5-50, more preferably 10-50.

That is, the ratio (L3 / L1) between the thickness L3 and the distance L1 between the inner peripheral surface 25a and the outer peripheral surface 8s of the main shaft 8 (large diameter portion 8a) is preferably 5-50. The slinger 25 may be configured to be 50 and positioned in the space S.
As an example, in this embodiment, in order to maximize the effect of preventing the gear lubricating grease from entering the air layer Ly and, as a result, preventing the gear lubricating grease from leaking to the outside of the unit, as described above, the air layer Ly The ratio of the depth (L3) to the width (L1), that is, the ratio of the thickness L3 of the slinger 25 to the distance L1 between the inner peripheral surface 25a and the outer peripheral surface 8s of the main shaft 8 (large diameter portion 8a) (L3 / L1) is set to 50.

  Further, as described above, according to the present embodiment, during operation of the rotary blade unit U1, the gear lubrication grease actively flows and circulates in the space S, so that the drive shaft gear G1 and the main shaft gear G2 are circulated. Thus, the gears G1 and G2 can be maintained in a good lubrication state over a long period of time. Further, since the gear lubrication grease can be prevented from leaking (intruding) into the rotary blade side bearing 2, the rotary blade side bearing 2 is maintained in a good lubrication state for a long period of time during the operation of the rotary blade unit U1. , Can continue to rotate accurately.

  Further, the slinger 25 covers the seal 20 in a state where the distance between the slinger lower surface 25b and the seal 20 is reduced as much as possible (for example, the distance L2 shown in FIG. 1B is set to approximately 0.25 mm). Therefore, the gear lubricating grease does not directly press the seal 20 and does not directly contact the sliding contact portion between the seal lip 201 of the seal 20 and the seal groove of the inner ring 10. As a result, it is possible to more effectively prevent the gear lubricating grease from leaking (invading) into the rotary blade side bearing 2.

  In addition, as described above, the seal 20 located on the drive shaft gear G1 and main shaft gear G2 side (upper side in FIG. 1B) has a pressure inside the bearing at both the outer diameter portion and the inner diameter portion. Since no through hole (a through hole corresponding to the through hole 22h formed in the seal 22) is provided to suppress the change, gear lubricating grease leaks (intrudes into) the rotary blade side bearing 2 from the through hole. However, there is no inconvenience such as mixing with bearing lubricating grease.

  As described above, according to the rotary blade unit U1 according to the present embodiment, the slinger 25 that is always stationary is provided on the gears G1, G2 side of the rotary blade side bearing 2, and the inside (for example, the space portion S and Leakage of grease enclosed in the inside of the rotary blade side bearing 2) can be reliably prevented. As a result, the lubrication state of the rotary blade unit U1 is maintained well, and wear of the drive shaft gear G1 and the main shaft gear G2 and 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 (hereinafter referred to as a first test) was performed and verified with respect to the leakage preventing effect of the grease enclosed in the mounted rotary blade unit U1. Hereinafter, the contents and results of the first test will be described.
In the first test, five mowers (corresponding to the mower A shown in FIG. 9A) are prepared as test machines, and three of these mowers have a rotary blade unit provided with a slinger 25 ( A conventional rotary blade unit (rotary blade unit U2 shown in FIG. 9 (b)) in which the rotary blade unit U1) shown in FIG. 1 (a) is mounted and the remaining two mowers are not provided with the slinger 25 is provided. Equipped with.

  The three mowers provided with the slinger 25 for the rotary blade unit include a predetermined lubricant for the inside of each rotary blade unit (the space S shown in FIGS. 1A and 9B). A predetermined amount (9.1 g, 5.7 g and 11.4 g) of Duplex EP No. 2 (hereinafter referred to as gear lubrication grease) manufactured by Kyodo Yushi Co., Ltd. was filled. Here, in the following description, the mowing machine filled with 9.1 g of gear lubrication grease inside the rotary blade unit is the machine 11, the mower filled with 5.7 g is the machine 12, and the grass mower is filled with 11.4 g. This is referred to as a comparator 11. Note that these filling amounts are approximately 80% of the volume of the machine 11, approximately 50% of the volume of the machine 12 with respect to the space volume inside the rotary blade unit (space part S), and the comparison machine. 11 corresponds to a volume amount of approximately 100%.

  On the other hand, a predetermined amount (10.8 g and 6.8 g) of gear lubrication grease similar to those of the machines 11 and 12 and the comparator 11 described above is also applied to the two mowing machines not provided with the slinger 25 for the rotary blade unit. ) Only filled. Here, in the following description, a mower filled with 10.8 g of the gear lubricating grease in the rotary blade unit is referred to as a comparator 12, and a mower charged with 6.8 g is referred to as a comparator 13. These filling amounts correspond to a volume amount of about 80% for the comparator 12 and a volume amount of about 50% for the comparator 13 with respect to the space volume inside the rotary blade unit (space S). .

  In this case, the space volume inside the rotary blade unit (space S) is smaller by the volume of the slinger 25 than the comparators 11 and 12 and the comparators 11 and 13. In this test, the volume of the slinger 25 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.

  Further, as a rolling bearing that supports the main shaft of each rotary blade unit (the rotary blade side bearing 2 shown in FIGS. 1A and 9B), the bearing outer diameter is 32 mm, the bearing inner diameter is 12 mm, and the bearing width is set. A ball bearing set to 10 mm and fitted with a contact type rubber seal to seal the inside was used. 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.

  FIG. 3 (a) shows a test device for verifying the grease leakage prevention effect of the rotary blade unit mounted on the mower, and using the test device, the machines 11, 12 and the comparator 11 , 12 and 13 are operated for a predetermined time at a predetermined speed (rotational speed of the cutting blade) under predetermined conditions, respectively, and then the gear lubrication grease enclosed in the rotary blade unit and the rolling bearing (rotary blade side bearing) ) The grease leakage prevention effect of the rotary blade unit for these mowers was verified by comparing the leakage state of the bearing lubricating grease sealed inside.

  As shown in FIG. 3 (a), the test device 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 mower operating tube 30 and the operation handle 36 (see FIG. 9A) so that the mower is suspended in the test apparatus. Was fixed to the frame material of the test apparatus with a string.

  In the first test, the atmospheric temperature of the mowers under test (the machines 11, 12, and the comparators 11, 12, 13) is kept at room temperature, and in this state, the speed at which the cutting blade rotates 8000 per minute. The machines 11, 12 and the comparators 11, 12, 13 were each continuously operated for a maximum of 30 hours. After that, remove the rotary blade unit from the machine 11, 12 and the comparators 11, 12, 13 and grease leaked from the inside of the rolling bearing (rotary blade side bearing) (bearing lubrication grease or bearing lubrication grease and gear lubrication grease) (Hereinafter, these leaked greases are simply referred to as grease) and collected with a spatula (small spoon), and the amount of leakage is collected for this machine 11,12 and comparators 11,12,13. Each was measured and compared. In this test, the operation of the mower (the machines 11, 12 and the comparators 11, 12, 13) and the measurement of the amount of grease leakage were taken as one test cycle, and the test cycle was repeated twice. Each was compared.

  FIG. 3B shows the results of each test. As is apparent from FIG. 3B, in the case of the comparator 12 and the comparator 13 not provided with the slinger 25, a rolling bearing (rotating blade side bearing). The amount of grease leakage from the engine was 4 g or more at the time when 12 hours before the operation time reached 30 hours (Comparator 12) and 15 hours (Comparator 13). A large amount of grease (more than 10 times) leaked (approximately 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 has reached the cutting blade, and when the comparator 12 has been operated for 12 hours, the comparator 13 has been tested for 15 hours. Canceled.

On the other hand, in the case of the present machines 11 and 12 provided with the slinger 25, the amount of grease leakage from the rolling bearing (rotating blade side bearing) is 0.04 even after the operation time has passed 30 hours. ~ 0.16g, which is only about 10-40% of the amount of bearing lubrication grease enclosed in the bearing (about 0.4g), and 1-4% of the grease leakage amount (4g or more) of the comparators 12 and 13 It was only a degree.
The amount of grease leakage relative to the amount of gear lubrication grease filled in the rotary blade unit (space S) is about 1.2 to 1.7% for the machine 11 and 0.7 for the machine 12. It was only about 1.2%.

  However, even in the case of the mower provided with the slinger 25, in the case of the comparator 11, the amount of grease leakage from the rolling bearing (rotary blade side bearing) is 10 hours before the operation time reaches 30 hours. The amount of leakage was equal to or greater than 4 g, which was equivalent to the above-described comparators 12 and 13. For this reason, the test was stopped when the operating time passed 10 hours.

As described above, by providing the slinger 25 as in the rotary blade unit U1 according to the present embodiment, the grease (gear lubrication grease and bearing lubrication grease) sealed inside the rotary blade unit U1 (space portion S) is provided. It has been verified by the above-described first test that the cutting blade 32 that is the rotating member can be stably rotated with a constant rotational accuracy over a long period of time.
Further, the amount of gear lubrication grease filled in the rotary blade unit (space S) is approximately 50 to 80% of the volume of the space inside the rotary blade unit (space S). The optimal amount was verified by the first test described above.

  Moreover, in addition to the 1st test mentioned above, the 2nd test was done with respect to the mower which concerns on this embodiment, and it verified further about the leakage prevention effect of the grease enclosed inside the rotary blade unit U1 mounted. The contents of the second test and the results will be described below.

  In the second test, five grass mowers (corresponding to the grass mower A shown in FIG. 9A) equipped with a rotary blade unit (the rotary blade unit U1 shown in FIG. 1A) provided with a slinger 25 as a test machine. ) Was prepared. In this case, the rolling bearing that supports the main shaft of the rotary blade unit (the rotary blade side bearing 2 shown in FIG. 1 (a)) has a distance H1 shown in FIG. 1 (b) of 2.5 mm and a distance H2 of 2.5 mm. The same distance L3 is set to 5.0 mm, and the same distance L1 (the interval (gap) between the inner peripheral surface of the slinger 25 and the outer peripheral surface of the main shaft (large diameter portion)) is changed from 0.1 mm to 1.5 mm. Set. Specifically, the rotation with a built-in bearing in which the clearance L1 is set to five values of 0.1 mm, 0.2 mm, 0.5 mm, 1.0 mm, and 1.5 mm and the clearance L1 is set to 0.1 mm. The mower with the blade unit is the machine 21, the mower with the 0.2mm set is the machine 22, the mower with the 0.5mm is the machine 23, and the mower is set with 1.0mm. Is the machine 24, and the mower set to 1.5 mm is referred to as a comparator 21.

  Note that these mowers (the machines 21, 22, 23, 24 and the comparator 21) include a predetermined lubricant for the inside of each rotary blade unit (the space S shown in FIG. 1A). (Kyodo Yushi Co., Ltd. Duplex EP No. 2 (Gear lubrication grease of the first test described above)) 9.1 g (volume of about 80% with respect to the space volume inside the rotary blade unit (space S)) Only).

  As for the rolling bearing (rotary blade side bearing 2 shown in FIG. 1 (a)), as in the first test, the outer diameter of the bearing is set to 32 mm, the inner diameter of the bearing is set to 12 mm, and the bearing width is set to 10 mm. A ball bearing with a sealed inside was used. Further, the slinger 25 is made of MC nylon, and the contact type rubber seal is not formed with a through hole (air hole) for suppressing (adjusting) the pressure change inside the bearing, so that the inside of the bearing is almost completely sealed. To keep it. Also, inside the bearing, as the lubricant, the thickener is lithium soap and the base oil is mineral oil-based grease (Shell Albanian Grease S2 (Showa Shell Sekiyu Co., Ltd., the above-mentioned bearing lubrication grease)). About 0.4 g was enclosed.

  Then, using the same test apparatus as the first test shown in FIG. 3 (a), the machine 21, 22, 23, 24 and the comparator 21 are moved at a predetermined speed (rotational speed of the cutting blade) under predetermined conditions. )), After each operation for a predetermined time, by comparing the leakage state of the gear lubrication grease enclosed in the rotary blade unit and the bearing lubrication grease enclosed in the rolling bearing (rotary blade side bearing) to the outside, The effectiveness of the rotary blade unit for preventing grease leakage against these mowers was verified.

  In the second test, the atmospheric temperature of the mowing machine under test (the machines 21, 22, 23, 24, and the comparator 21) is kept at room temperature, and in this state, the cutting blade rotates at 8000 revolutions per minute, Each of the machines 21, 22, 23, 24 and the comparator 21 were continuously operated for 30 hours. Thereafter, the rotary blade unit is removed from the present machine 21, 22, 23, 24 and the comparator 21, and grease leaked from the inside of the rolling bearing (rotary blade side bearing) (bearing lubrication grease or bearing lubrication grease and gear lubrication grease). (Hereinafter, these leaked greases are simply referred to as grease) are collected with a spatula (small spoon), and the leakage amount is measured for this machine 21, 22, 23, 24 and comparator 21. Each was measured and compared.

  FIG. 6 shows the test results. As is apparent from FIG. 6, in the case of the comparator 21 in which the clearance L1 is set to 1.5 mm, the amount of grease leakage reaches approximately 4.0 g, A large amount of grease (more than 10 times) leaked from the amount enclosed (approximately 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 has reached the cutting blade and contaminated the surrounding environment (plants, soil, etc.) (state of grease Gs shown in FIG. 8C).

  On the other hand, in the case of the machines 21, 22, and 23 where the clearance L1 is set to 0.1 to 0.5 mm, the amount of grease leakage is about 0.14 to 0.22 g, and the bearing lubrication grease is enclosed inside the bearing. It was only about 35 to 55% of the amount (about 0.4 g), and only about 3 to 5% of the grease leakage amount of the comparator 21 (about 4.0 g). Further, the grease leakage amount relative to the amount (9.1 g) of gear lubrication grease filling the rotary blade unit (space S) was only about 1.5 to 2.4%. In this case, the leaked grease remained in the vicinity of the surface of the rubber seal of the rolling bearing (rotary blade side bearing) (state of grease Gs shown in FIG. 8A).

  However, in the case of this machine 24 in which the clearance L1 is set to 1.0 mm, the amount of grease leakage is about 1.0 g, and the leaked grease does not reach the cutting blade, but the rotary blade unit and the spacer ( The state of staying in the space between the cutting blade presser lid) (the state of the grease Gs shown in FIG. 8B).

  Considering the results of the second test, the ratio of the distance L3 (FIG. 1 (b)) to the clearance L1 (L3 / L1) is 5 (corresponding to the machine 24) to 50 (this case). It was verified that the grease leakage prevention effect to the outside of the unit was high. Furthermore, by setting the ratio (L3 / L1) to 10 (corresponding to the machine 23) to 50 (corresponding to the machine 21), the effect of preventing leakage of grease to the outside of the unit can be further enhanced. It was verified by the second test described above.

  Even when the ratio of the distance L3 to the clearance L1 (L3 / L1) is set in the range of 5 to 50, if the clearance L1 is set to a dimension smaller than 0.1 mm (L1 <0.1 mm). There is a possibility that the main axis of the rotary blade unit (the main axis 8 shown in FIG. 1B) and the slinger 25 come into contact with each other. Therefore, the clearance L1 is set to a dimension of 0.1 mm or more (L1 ≧ 0.1 mm), and the ratio of the distance L3 to the clearance L1 (L3 / L1) is set to 5 to 50, more preferably 10 to 50. Good.

“Second Embodiment”
In FIG. 2, a second embodiment of the present invention is provided, wherein a slinger 45 in which only the shape of the slinger 25 of the rotary blade unit U <b> 1 (FIG. 1B) according to the first embodiment described above is changed is provided. The rotary blade unit U11 which concerns on a form is shown.
In the rotary blade unit U11, the slinger 45 is configured by providing a concave groove (hereinafter referred to as an air groove) 25g continuous over the entire circumference on the inner circumferential surface 25a. In this case, as an example, the air groove 25g has a bottom portion 25v that is continuous in a circular shape along the circumferential direction of the inner peripheral surface 25a, and is continuous over the entire circumference at both ends of the bottom portion 25v. As a groove having a rectangular shape in a longitudinal sectional view, which is formed by a pair of wall portions 25w that stand up in the diameter-enlarging direction of the slinger 45 and oppose each other, the groove 1 is positioned at a substantially intermediate position in the thickness direction of the slinger 45 (vertical direction in FIG. Only books are provided.

It should be noted that the size (width (vertical distance in FIG. 2) and depth (horizontal distance in FIG. 2)), shape, number, formation position, etc. of the air groove 25g are the size of the slinger 45 (outside the whole). The diameter, overall inner diameter, cross-sectional diameter, thickness, etc.) and shape may be arbitrarily set, and are not particularly limited here.
For example, in the configuration shown in FIG. 2, the air groove 25 g is formed in a rectangular shape in the longitudinal section, but in addition to the rectangular shape in the longitudinal section, for example, the contour of the longitudinal section is curved or U-shaped. The air groove 25g may be configured as a groove or the like in which the bottom 25v is omitted and the wall portions 25w facing each other are directly continuous, and the vertical cross-sectional profile is V-shaped. Further, the air groove 25g may be spirally continued along the circumferential direction of the inner peripheral surface 25a, and the bottom portion 25v is wavy along the circumferential direction of the inner peripheral surface 25a (the outline of the cross section is wavy). It may be continuous.
However, the air groove 25g does not have to be continuous over the entire circumference of the inner peripheral surface 25a. For example, a plurality of grooves are intermittently provided along the circumferential direction of the inner peripheral surface 25a, and the whole of these grooves is formed. The configuration may be a substantially circular configuration.
Furthermore, a plurality of air grooves 25g may be formed. In this case, the air grooves 25g having various shapes may be combined.

  Further, in the rotary blade unit U11 according to the second embodiment, the basic member configuration other than the shape of the slinger 45 is the same as that of the rotary blade unit U1 according to the first embodiment described above, and therefore the same in the drawings. The description thereof will be omitted. For example, the thickness L3 of the slinger 45, the interval L1 between the inner peripheral surface 25a of the slinger 45 and the outer peripheral surface 8s of the main shaft 8 (large diameter portion 8a), the interval L2 between the slinger lower surface 25b and the sealing member 20, etc. It is set to the same value as the slinger 25 of the rotary blade unit U1 according to the first embodiment described above.

  Also in the second embodiment, as in the first embodiment described above, an air flow in the rotation direction of the main shaft 8 can be generated with respect to the air layer Ly as the main shaft 8 rotates. In this case, since the cross-sectional area of the air layer Ly is different between the air groove 25g and the other parts, the peripheral speed of the air flow is different between the air groove 25g and the other parts of the air layer Ly. Arise. Specifically, the circumferential speed in the air groove 25g is larger (faster) than the other circumferential speeds. As a result, in the air layer Ly, air flow layers having different peripheral velocities can be generated, and even if the pressing force is applied to the slinger 45 accompanying the increase in the internal pressure of the rotary blade unit U11, the pressing force Can be loaded by an air flow layer, that is, a stress that can be opposed to the pressing force can be generated by the air flow layer. Thereby, it is possible to effectively prevent the gear lubricating grease from entering the air layer Ly.

  In the second embodiment described above, the cross-sectional area of the air layer Ly in the air groove 25g is enlarged, but the air groove 25g is substantially in the middle of the thickness direction of the slinger 45 (vertical direction in FIG. 2). At the upper end and the lower end in the thickness direction of the air layer Ly, the distance L1 between the inner peripheral surface 25a of the slinger 45 and the main shaft 8 (large diameter portion 8a) is the same as in the first embodiment described above. Is narrowed as much as possible (as an example, L1 is set to about 0.1 mm), so that there is no particular problem. Other effects are the same as those in the first embodiment described above.

“Third Embodiment”
FIG. 4 shows a third embodiment of the present invention, characterized in that a main shaft 80 in which only the shape of the main shaft 8 of the rotary blade unit U1 (FIG. 1 (b)) according to the first embodiment is changed is provided. The rotary blade unit U12 which concerns on a form is shown. Hereinafter, the configuration of the rotary blade unit U12 according to the third embodiment will be described. In this case, in the rotary blade unit U12, the basic member configuration other than the shape of the main shaft 80 is the same as that of the rotary blade unit U1 (FIG. 1B) described above. In the drawings, the same reference numerals are given and description thereof is omitted.

In the rotary blade unit U12, as shown in FIG. 4, at least a portion of the main shaft 80 facing the inner peripheral surface 25a of the slinger 25 (hereinafter referred to as a facing portion) 80d is set to the inner periphery rather than the outer periphery of the main shaft 8. The diameter is increased by a predetermined size (distance S2 (radius value) shown in the figure) toward the surface 25a.
As an example, in the configuration shown in FIG. 4, the upper side in the axial direction (extending direction of the main shaft 80, that is, the vertical direction (vertical direction in the figure)) of the facing portion 80d with the facing portion 80d as a boundary By reducing the diameter by the size (distance S2 (radius value) shown in the figure) (so-called meat stealing), the facing portion 80d of the main shaft 80 is directed toward the inner peripheral surface 25a of the slinger 25 to a predetermined size. The structure is projected by a distance (distance S2 (radius value) shown in the figure). In this case, since the facing portion 80d is provided on the large diameter side, that is, the large diameter portion 80a of the main shaft 80 with the stepped portion 80g as a boundary, the main shaft 80 is disposed on the lower side in the axial direction of the facing portion 80d. The small diameter portion 80b is provided.

  On the other hand, in this case, the slinger 25 is fixed to the inner wall 40s of the case 40 (for example, an interference fit), and the slinger upper surface 25c is placed on the side of the gear G1, G2 (FIG. 1 (a)) of the opposed portion 80d of the main shaft 80. Side surface (upper surface in FIG. 4 (hereinafter referred to as the upper surface of the opposing portion)) 80t in the axial direction (rotating blade side bearing 2 side (lower side in the figure)) by a predetermined size (distance S1 shown in the same drawing) It is positioned to be recessed. In other words, the opposing portion 80d of the main shaft 80 is configured so that the opposing portion upper surface 80t is more than the gear G1, G1 than the slinger upper surface 25c in a state where the slinger 25 is fixed (for example, interference fit) to the inner wall S1 of the case 40. It is configured to project by a distance S1 toward G2 (FIG. 1 (a)) (upper side in FIG. 4). That is, the width (axial dimension (vertical distance in FIG. 4)) of the facing portion 80d is the axial dimension (namely, the thickness of the slinger 25 (distance L3 shown in FIG. 4) of the slinger 25). ) And a predetermined dimension (distance S1).

Here, the size (protruding distance (distance S2 shown in FIG. 4), width, etc.) of the opposing portion 80d of the main shaft 80, the size of the meat theft, etc., can be arbitrarily set according to the size and shape of the slinger 25. Since it may be sufficient, it does not specifically limit. However, the opposing portion 80d of the main shaft 80 and the slinger 25 are such that the opposing portion upper surface 80t is at least the same height as the slinger upper surface 25c in the axial direction, or the opposing portion upper surface 80t is higher in the axial direction than the slinger upper surface 25c. Needs to be positioned.
As an example, in the present embodiment, the protruding distance (distance S2 shown in FIG. 4) of the opposing portion 80d to the inner peripheral surface 25a of the slinger 25 is about 1.5 mm, and the protruding distance of the opposing portion upper surface 80t to the slinger upper surface 25c ( The size of the facing portion 80d is set so that the distance S1) shown in the figure is about 1 mm (if another way of understanding is set, the size of meat stealing), and the slinger 25 is positioned. Assume a case.

  In the configuration shown in FIG. 4, as an example, the width of the facing portion 80d (the dimension in the axial direction (vertical direction in the figure)) is set to a predetermined dimension larger than the thickness L3 of the slinger 25. As long as the slinger 25 is positioned in a state where the slinger upper surface 25c is recessed by a predetermined size (as an example, the distance S1 shown in the figure) with respect to the upper surface 80t of the opposing portion, the width of the opposing portion 80d is It may be the same dimension as the thickness L3 of the slinger 25, or may be smaller than the thickness L3 of the slinger 25.

  In the configuration shown in FIG. 4, as an example, the opposing portion 80 d is formed in a flat surface shape in which the opposing portion upper surface 80 t is not inclined in any axial direction over the entire circumference. You may form the opposing part upper surface 80t in the flat surface shape which inclined in any one side of the axial direction. Further, for example, the facing portion 80d may be formed by continuously forming the facing portion upper surface 80t in a concavo-convex shape (as an example, a wave shape) along the circumferential direction.

  According to such a configuration, even if the main shaft 80, the inner ring 10, the drive shaft gear G1 and the main shaft gear G2 (FIG. 1A) rotate, the slinger 25 does not rotate together with the non-rotating portion. The inner peripheral surface 25a is kept in a rotating state (that is, a stationary state), and a predetermined distance (see FIG. The distance L1) shown in FIG. Further, the slinger 25 can have the inner peripheral surface 25a and the slinger upper surface 25c opposed to the inner ring 10, the drive shaft gear G1, and the main shaft gear G2 in a rotating state with a predetermined interval therebetween.

  As an example, in the present embodiment, the distance (the distance L1 shown in FIG. 4) between the inner peripheral surface 25a of the slinger 25 and the opposing surface 80s of the opposing portion 80d is about 0.1 mm, the slinger upper surface 25c and the drive shaft gear G1 ( It is assumed that the inner and outer diameter dimensions of the slinger 25 are set so that the distance from FIG. 1A) is about 2 mm, and the thickness (distance L3 shown in FIG. 1) is set to about 5 mm. Further, since the slinger 25 is positioned so that the slinger lower surface 25b is substantially flush with the side surface 12c of the outer ring 12 of the rotary blade side bearing 2, the distance between the slinger lower surface 25b and the seal 20 (the distance shown in FIG. 4). L2) substantially coincides with the depth of the recess from the side surface 12c of the outer ring 12, and is about 0.25 mm.

  Also in the rotary blade unit U12 configured as described above, the drive shaft gear G1 and the main shaft gear G2 (FIG. 1A) using the same grease (gear lubrication grease and bearing lubrication grease) as in the first embodiment described above. ), The rotary blade side bearing 2 is lubricated. At that time, the filling amount (filling) of the gear lubrication grease may be set in the same manner as in the first embodiment described above (preferably a volume ratio of about 30 to 90% with respect to the space volume of the space portion S, more preferably. Is a volume ratio of about 50 to 80%). In this case, the space volume of the space portion S is the same as that of the rotary blade unit U1 (FIG. 1B) according to the first embodiment by an amount corresponding to the volume of the meat stealing provided on the main shaft 80. Compared to the case where no is provided. Further, the amount (filling) of the bearing lubrication grease may be set in the same manner as in the first embodiment described above (preferably with a volume ratio of about 25 to 35% with respect to the space volume in the rotary blade side bearing 2. Amount).

Here, the usage state of the mower according to the present embodiment, that is, the state change of the gear lubrication grease during the operation of the rotary blade unit U12 will be described below.
The gear-lubricating grease has a space portion due to its own weight and vibration caused by the rotation of the main shaft 80 and the main shaft gear G2 (FIG. 1A) while the driving shaft 38 and the driving shaft gear G1 (FIG. 1A) rotate. Stir and shear continuously in S. The gear lubricating grease that has been repeatedly stirred and sheared as described above rises in temperature, and is softened and thermally expanded.

At this time, since the pressure (internal pressure) inside the rotary blade unit U12 (space part S) rises, the rotary blade unit U12 has the internal pressure of the rotary blade unit U12 and the gear lubricating grease sealed in the space part S. The outward pressing force, specifically, the pressing force on the inner wall 40s of the case 40, the main shaft 80, and the slinger 25 acts, and the gear lubrication grease falls and contacts the opposing portion upper surface 80t and the slinger upper surface 25c. .
In this state, the slinger 25 is stationary, but on the other hand, the main shaft 80 is rotating, so that the gear lubrication grease in contact with the upper surface 80t of the facing portion and the gear lubrication grease in contact with the slinger upper surface 25c Centrifugal force generated by the rotation of the main shaft 80 and the upper surface 80t of the facing portion acts.

  The gear lubrication grease to which the centrifugal force is applied moves above the space portion S through the inner wall 40s of the case 40, the surface of the drive shaft gear G1, and the surface of the main shaft gear G2 by the centrifugal force. Then, after reaching the vicinity of the main shaft 80, the gear lubrication grease falls and contacts the opposing portion upper surface 80t and the slinger upper surface 25c of the main shaft 80 again due to its own weight and vibration caused by the rotation. As a result, the gear lubricating grease is circulated in the space S.

  In the present embodiment, the slinger 25 is provided without making contact with the drive shaft gear G1 and the distance between the drive shaft gear G1 is reduced as much as possible (as an example, the distance between the slinger upper surface 25c and the drive shaft gear G1 is about 2 mm). Therefore, the gear lubricating grease can be easily drawn into the drive shaft gear G1. 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. .

  Furthermore, in the present embodiment, the main shaft 80 is provided with a facing portion 80d (if another way of understanding is used, a meat stealer is provided), and the facing portion upper surface 80t of the facing portion 80 is more than the slinger upper surface 25c of the slinger 25. Since only the distance S1 is set to the upper side in the axial direction (set to about 1 mm as an example), when the gear lubricating grease falls on the opposing portion upper surface 80t before falling on the slinger upper surface 25c, the opposing portion upper surface 80t It receives the action of the centrifugal force generated by the rotation of. For this reason, most of the gear lubricating grease circulates in contact with the upper surface 80t of the facing portion in the space S. That is, in the flow of the gear lubricating grease in the space S, the circulation flow that circulates in contact with the upper surface 80t of the opposing portion becomes the main flow, and the circulation flow that circulates in contact with the slinger upper surface 25c becomes the subflow.

  As described above, the gear lubrication grease actively flows in the space S during use of the mower, that is, during the operation of the rotary blade unit U12, and circulates with little contact with the slinger upper surface 25c (described above). Repeated). For this reason, the gear lubrication grease does not stay (deposit) on the slinger upper surface 25c and eventually the outer surface of the seal 20 (the surface on the side of the drive shaft gear G1 and the main shaft gear G2) and does not press the seal 20. As a result, it is possible to reliably prevent the gear lubricating grease from leaking (invading) into the rotary blade side bearing 2.

  Further, in the present embodiment, the slinger 25 is provided with the space between the facing surface 80s as narrow as possible without contacting the facing surface 80s of the facing portion 80d (as an example, between the inner peripheral surface 25a and the facing surface 80s). By setting the distance (the distance L1 shown in FIG. 1B to about 0.1 mm), the thickness of the slinger 25 between the inner peripheral surface 25a and the opposing surface 80s (the distance L3 shown in FIG. As an example, the air layer Ly can be formed at a depth corresponding to 5 mm)). In this case, the ratio of the depth (corresponding to the thickness L3 of the slinger 25) and the width (corresponding to the distance L1 between the inner peripheral surface 25a and the opposing surface 80s) of the air layer Ly is sufficiently large (for example, L3 / L1). = 50) Therefore, an air flow in the rotation direction is generated in the air layer Ly as the main shaft 80 rotates.

  For this reason, even when a pressing force is applied to the slinger 25 due to an increase in the internal pressure of the rotary blade unit U1, the pressing force is loaded by the air flow of the air layer Ly, that is, by the air flow of the air layer Ly. Thus, stress capable of resisting the pressing force can be generated, and the gear lubricating grease can be effectively prevented from entering the air layer Ly. Even when the gear lubrication grease is softened and easily flows as described above, if the air flow in the air layer Ly is longitudinally cut, the gear lubrication grease after the longitudinal cut will be the seal lip of the seal 20. There is no pressing force enough to slip through the sliding contact portion between 20l and the seal groove of the inner ring 10.

  As a result, it is possible to reliably prevent the gear lubrication grease from leaking into (intruding into) the inside of the rotary blade side bearing 2, and thus effectively preventing the gear lubrication grease from leaking (outflowing) to the outside of the rotary blade unit U12. can do. As a result, since the gear lubrication grease does not leak (outflow), the gear lubrication grease can always be kept at an appropriate amount. Therefore, the drive shaft gear G1 and the main shaft gear G2 do not become insufficiently lubricated, and the teeth of the gears G1, G2 are also prevented from being frictioned and worn (damaged) with each other. It can be rotated smoothly over the range. Further, since leakage (outflow) of the gear lubrication grease to the outside of the unit is prevented, contamination to the surrounding environment (such as vegetation and soil) can be more effectively prevented. Other effects are the same as in the case of the first embodiment described above.

  Note that the ratio (L3 / L1) of the depth (L3) to the width (L1) of the air layer Ly, that is, the thickness L3 of the slinger 25, and the distance (gap between the inner peripheral surface 25a and the opposed surface 80s of the opposed portion 80d). The ratio (L3 / L1) to L1 may be set in the same manner as in the first embodiment described above. Specifically, the ratio (L3 / L1) is preferably set to 5 to 50, more preferably 10 to 50. In that case, the clearance L1 may be set to a dimension of 0.1 mm or more (L1 ≧ 0.1 mm). As an example, in this embodiment, the ratio (L3 / L1) is set to 50 in order to maximize the effect of preventing the gear lubricating grease from entering the air layer Ly, that is, the effect of preventing the gear lubricating grease from leaking to the outside of the unit. (The clearance L1 is set to about 0.1 mm).

Here, with respect to the mower according to the present embodiment, a predetermined test (hereinafter, referred to as a third test) was performed to verify the leakage preventing effect of the grease enclosed in the mounted rotary blade unit U12. The test contents and test results will be described below.
In the third test, five mowers (corresponding to the mower A shown in FIG. 9A) are prepared as test machines, and three of these mowers are provided with a rotary blade slinger 25 and opposed to each other. A rotary blade unit (rotary blade unit U12 shown in FIG. 4) provided with a portion 80d (or stealing meat in another way) is mounted, and the remaining two mowers include a slinger 25 and an opposing portion 80d ( A conventional rotary blade unit (rotary blade unit U2 shown in FIG. 9 (b)) provided with no meat stealing was mounted.

  The three blade mowers provided with the slinger 25 and the facing portion 80d with respect to the rotary blade unit have predetermined lubrication with respect to the inside of each rotary blade unit (the space S shown in FIGS. 4 and 9B). A predetermined amount (9.6 g, 6.0 g, and 12 g) of an agent (duplex EP No. 2 manufactured by Kyodo Yushi Co., Ltd. (the gear lubrication grease of the first test described above)) was filled. Here, in the following description, a mower filled with 9.6 g of gear lubrication grease inside the rotary blade unit is the machine 31, a mower filled with 6.0 g is the machine 32, and a mower filled with 12 g is a comparative machine. 31. Note that these filling amounts are approximately 80% of the volume of the machine 31, approximately 50% of the volume of the machine 32 with respect to the space volume inside the rotary blade unit (space S), and the comparison machine. 31 corresponds to a volume amount of approximately 100%.

  On the other hand, two mowers that are not provided with either the slinger 25 or the opposed portion 80d with respect to the rotary blade unit are also provided with a predetermined amount (10 of gear lubrication grease similar to that of the machines 31 and 32 and the comparator 31 described above. .8 g and 6.8 g). Here, in the following description, a mower filled with 10.8 g of the gear lubricating grease in the rotary blade unit is referred to as a comparator 32, and a mower charged with 6.8 g is referred to as a comparator 33. Note that these filling amounts correspond to a volume amount of about 80% for the comparator 32 and a volume amount of about 50% for the comparator 33 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 in the present machine 31, 32 and the comparator 31 than in the comparators 32, 33 by the volume of the slinger 25. In this test, the volume of the slinger 25 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. In addition, the space volume inside the rotary blade unit (space S) is larger in the present machines 31, 32 and the comparator 31 than in the comparators 32, 33 by the volume of the stealing provided on the main shaft. In this test, the volume of the meat theft is set to about 0.64 cc, and the volume (0.64 cc) corresponds to about 0.6 g in terms of the weight of the gear lubricating grease.

  Further, as the rolling bearing (rotating blade side bearing 2 shown in FIGS. 4 and 9B) supporting the main shaft of each rotating blade unit, the bearing outer diameter is 32 mm, the bearing inner diameter is 12 mm, as in the first test. A ball bearing in which the bearing width was set to 10 mm and a contact type rubber seal was attached to seal the inside was used. 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. Also, inside the bearing, as the lubricant, the thickener is lithium soap and the base oil is mineral oil-based grease (Shell Albany Grease S2 (Showa Shell Oil Co., Ltd., the above-mentioned bearing lubrication grease)). About 0.4 g was enclosed.

  Then, using the same test apparatus as in the first test shown in FIG. 3 (a), the machines 31, 32 and the comparators 31, 32, 33 are moved at a predetermined speed (rotational speed of the cutting blade) under predetermined conditions. )), After each operation for a predetermined time, by comparing the leakage state of the gear lubrication grease sealed inside the rotary blade unit and the bearing lubrication grease sealed inside the rolling bearing (rotary blade side bearing) to the outside, The effectiveness of the rotary blade unit for preventing grease leakage against these mowers was verified.

  In the third test, the atmospheric temperature of the mowing machine under test (the machine 31, 32 and the comparator 31, 32, 33) is kept at room temperature, and in this state, the cutting blade rotates at 8000 revolutions per minute, The machines 31, 32 and the comparators 31, 32, 33 were each continuously operated for a maximum of 30 hours. After that, remove the rotary blade unit from the machine 31, 32 and the comparator 31, 32, 33, and grease leaked from the inside of the rolling bearing (rotary blade side bearing) (bearing lubrication grease or bearing lubrication grease and gear lubrication grease) (Hereinafter, these leaked greases are collectively referred to as grease) and collected with a spatula (small spoon), and the leakage amount is measured for this machine 31, 32 and comparators 31, 32, 33. Each was measured and compared. In this test, the operation of the mower (the machine 31, 32 and the comparator 31, 32, 33) and the measurement of the amount of grease leakage were taken as one test cycle, and the test cycle was repeated twice. Each was compared.

  FIG. 7 shows the results of each test. As is apparent from FIG. 7, in the case of the comparator 32 and the comparator 33 not provided with the slinger 25, the grease from the rolling bearing (rotating blade side bearing). The leakage amount is 4 g or more at the time when 12 hours have passed before the operation time reaches 30 hours (comparator 32) and at the time when 15 hours have passed (comparator 33). More than 4g) grease (more than 10 times) leaked. 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 has reached the cutting blade, and when the comparator 32 has been operated for 12 hours, the comparator 33 has been tested for 15 hours. Canceled.

On the other hand, in the case of the machines 31 and 32 provided with the slinger 25, the amount of grease leakage from the rolling bearing (rotating blade side bearing) is 0.02 even after 30 hours of operation time. 0.07 g, which is only about 5 to 17% of the amount of bearing lubrication grease enclosed in the bearing (about 0.4 g), and the amount of grease leakage (4 g or more) of the comparators 32 and 33 is 0.5 to It was only about 1.7%.
The amount of grease leakage relative to the amount of gear lubrication grease filling the rotary blade unit (space S) is about 0.3 to 0.7% for the machine 31 and 0.3 for the machine 32. It was only about 0.5%.

  However, even in the case of the mower provided with the slinger 25, in the case of the comparator 31, the amount of grease leakage from the rolling bearing (rotating blade side bearing) is 10 hours before the operation time reaches 30 hours. The amount of leakage was equal to or greater than 4 g, which was equivalent to the above-described comparators 32 and 33. For this reason, the test was stopped when the operating time passed 10 hours.

As described above, in addition to providing the slinger 25 as in the rotary blade unit U12 according to the present embodiment, by providing the main shaft 80 with the opposing portion 80d (meal stealing) whose diameter is increased and widened with respect to the slinger 25, The grease (gear lubrication grease and bearing lubrication grease) enclosed in the inside (space S) of the rotary blade unit U12 can be surely prevented from leaking to the outside, and the cutting blade 32 that is a rotary member can be provided for a long time. It was verified by the above-described third test that it can continue to rotate stably with a constant rotational accuracy.
Further, the amount of gear lubrication grease filled in the rotary blade unit (space S) is approximately 50 to 80% of the volume of the space inside the rotary blade unit (space S). It was verified by the third test described above that the amount was optimal.

“Fourth Embodiment”
In FIG. 5, the slinger 45 (slinger having the same configuration as that of the second embodiment shown in FIG. 2) in which only the shape of the slinger 25 of the rotary blade unit U12 (FIG. 4) according to the third embodiment described above is changed is provided. A rotary blade unit U13 according to a fourth embodiment of the present invention is shown (in other words, the rotary blade unit U11 (FIG. 2) according to the second embodiment described above is characterized in that A unit configuration in which the main shaft 8 is provided with a facing portion 80d (meat stealing)).
In the rotary blade unit U13, the slinger 45 is provided with a concave groove (hereinafter referred to as an air groove) 25g continuous over the entire circumference of the inner peripheral surface 25a, as in the second embodiment described above. It is configured. In this case, as an example, the air groove 25g has a bottom portion 25v that is continuous in a circular shape along the circumferential direction of the inner peripheral surface 25a, and is continuous over the entire circumference at both ends of the bottom portion 25v. As a groove having a rectangular shape in a longitudinal sectional view, which is formed by a pair of wall portions 25w that rises in the diameter-enlarging direction of the slinger 45 and opposes each other, 1 is provided at a substantially intermediate position in the thickness direction of the slinger 45 (vertical direction in FIG. 5). Only books are provided.

  The size (width (vertical distance in FIG. 5) and depth (horizontal distance in FIG. 5)), shape, number, formation position, and the like of the air groove 25g are the same as the size of the slinger 45 (outside the whole). (Diameter, overall inner diameter, cross-sectional diameter, thickness, etc.) and shape may be arbitrarily set, and there is no particular limitation, and the same changes as in the second embodiment described above are possible.

  Further, in the rotary blade unit U13 according to the fourth embodiment, the basic member configuration other than the shape of the slinger 45 is the same as that of the rotary blade unit U12 according to the third embodiment described above, and therefore the same or similar configuration. Are given the same reference numerals in the drawings, and description thereof is omitted. For example, the thickness L3 of the slinger 45, the distance L1 between the inner peripheral surface 25a of the slinger 45 and the facing surface 80s of the facing portion 80d, and the distance L2 between the slinger lower surface 25b and the sealing member 20 are all described in the third embodiment. It is set to the same value as the slinger 25 of the rotary blade unit U12 according to the embodiment.

  Also in the fourth embodiment, as in the third embodiment described above, an air flow in the rotation direction of the main shaft 80 can be generated with respect to the air layer Ly as the main shaft 80 rotates. In this case, since the cross-sectional area of the air layer Ly is different between the air groove 25g and the other parts, the peripheral speed of the air flow is different between the air groove 25g and the other parts of the air layer Ly. Arise. Specifically, the circumferential speed in the air groove 25g is larger (faster) than the other circumferential speeds. As a result, in the air layer Ly, air flow layers having different peripheral velocities can be generated, and even if the pressing force is applied to the slinger 45 due to the increase in the internal pressure of the rotary blade unit U13, the pressing force Can be loaded by an air flow layer, that is, a stress that can be opposed to the pressing force can be generated by the air flow layer. Thereby, it is possible to effectively prevent the gear lubricating grease from entering the air layer Ly.

  In the fourth embodiment described above, the cross-sectional area of the air layer Ly in the air groove 25g is enlarged, but the air groove 25g is substantially in the middle of the thickness direction of the slinger 45 (vertical direction in FIG. 5). At the upper end and the lower end in the thickness direction of the air layer Ly, the distance L1 between the inner peripheral surface 25a of the slinger 45 and the main shaft 80 (opposing portion 80d) is the same as in the third embodiment described above. Since it is narrowed as much as possible (for example, L1 is set to about 0.1 mm), there is no particular problem. Other effects are the same as those of the third embodiment described above.

It is a figure which shows the structural example of the rotary blade unit which concerns on 1st Embodiment of this invention, Comprising: (a) is sectional drawing, (b) is sectional drawing which shows the structural example of the slinger provided in the rotary blade side bearing. . Sectional drawing which shows the structural example of the slinger provided in the rotary blade side bearing of the rotary blade unit which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the 1st test about the leakage prevention effect of the grease enclosed in the inside of 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) is a diagram showing the test results for each of the present machine and each comparator. Sectional drawing which shows the structural example of the slinger provided in the rotary blade side bearing of the rotary blade unit which concerns on 3rd Embodiment of this invention. Sectional drawing which shows the structural example of the slinger provided in the rotary blade side bearing of the rotary blade unit which concerns on 4th Embodiment of this invention. The figure which shows the result of the 2nd test about the leakage prevention effect of the grease enclosed in the inside of the rotary blade unit mounted in the mower about each machine and the comparator. The figure which shows the result of the 3rd test about the leakage prevention effect of the grease enclosed in the inside of the rotary blade unit mounted in the mower about each machine and each comparison machine. It is a figure which shows the leakage state of the grease in the 2nd test about the leakage prevention effect of the grease enclosed inside the rotary blade unit mounted in the mower, Comprising: (a) is a clearance L1 0.1-. A state diagram when 5 mm is set, (b) is a state diagram when the clearance L1 is set to 1.0 mm, and (c) is a state diagram when the clearance L1 is set to 1.5 mm. It is a figure which shows the structural example of the conventional mower, Comprising: (a) is a perspective view which shows the whole structure, (b) is sectional drawing of a rotary blade unit.

Explanation of symbols

2 Rotary blade side bearing 4 Gear side bearing 8 Main shaft 10 Inner ring 12 Outer ring 20, 22 Seal 25 Slinger 32 Cutting blade 34 Engine 36 Drive shaft G1 Drive shaft gear G2 Main shaft gear L1 Slinger-main shaft distance L2 Slinger-seal distance L3 Slinger Thickness Ly Air layer U1 Rotary blade unit

Claims (3)

A plurality of rolling bearings which are provided with a main shaft extending in a predetermined direction, a stationary wheel and a rotary wheel which are opposed to each other so as to be relatively rotatable, and rotatably support the main shaft, and are rotated by a driving device. In order to transmit the rotational force of the drive shaft to the main shaft, at least one set of gears which are respectively provided on one end side of the drive shaft and the main shaft and mesh with each other, and a rotating member attached to the other end side of the main shaft; A rotating member support unit comprising the main shaft, a rolling bearing and a case for housing a gear;
An annular slinger is provided in close contact with or close to the side surface of the stationary ring on the gear side of at least the rolling bearing arranged closest to the rotating member in order to prevent foreign matter from entering the rolling bearing. The slinger is positioned so as to face the main shaft at a predetermined interval, and is positioned so as to be in non-contact with both the rotating wheel of the rolling bearing and the gear, so that it is always kept stationary. A rotating member support unit.   In the rolling bearing disposed closest to the rotating member, at least a pair of sealing members forming a ring for sealing the inside of the rolling bearing are interposed between the stationary wheel and the rotating wheel with the rolling element interposed therebetween. The slinger is fixed to the inner wall of the case, and the side surface on the rolling bearing side is in close contact with the side surface on the gear side of the stationary ring, and is opposed to the sealing member with a predetermined interval. A rotating member supporting unit characterized in that the rotating member supporting unit is provided.   The rotating member support unit according to claim 1 or 2, wherein a cutting blade for cutting off the vegetation growing on the ground surface from near the root is attached to the main shaft.

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