JP2007321954A - 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 grease filled inside, to the outside by providing a slinger at a rolling bearing for pivoting a rotating member. <P>SOLUTION: The rotating member support unit comprises a main shaft 8 erected extending in a predetermined direction; a plurality of rolling bearings for supporting the main shaft 8 rotatably; at least a pair of gears G1, G2 provided at one end side of a driving shaft 38 and the main shaft and meshed to transmit the rotating force of the driving shaft 38 rotated by a driving device 34, to the main shaft; and the rotating member 32 mounted to the other end side of the main shaft. At least the rolling bearing 2 brought closest to the rotating member has at least a pair of annular sealing plates 20, 22 interposed between inner and outer rings 10, 12 to seal the inside of the rolling bearing, and the gear-side side face of the rolling bearing is provided with the annular slinger 24 for preventing the intrusion of foreign matter into the bearing. <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 a power tool used for cutting away vegetation (e.g., weeds) growing on the ground surface from the vicinity of the root, and in particular, a cutting blade attached thereto. The present invention relates to an improvement of a rotating member support unit that supports a rotating member such as a (rotating blade).

FIGS. 2A and 2B show an example of a configuration of a mower provided with such a rotating member support unit. In the configuration shown in the figure, the mower A includes an operation tube 30 extending linearly, a rotary blade unit (rotary member support unit) U2 provided on one end side of the operation tube 30, and the operation. A driving device (engine) 34 provided on the other end side of the 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 (drive shaft bearing). 6 is rotatably supported. A gear (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 so as to drive the drive shaft 38. The shaft 38 is rotatably supported.

  In addition, the rotary blade unit U2 includes a main shaft 8 extending in a predetermined direction and two rolling bearings (under the rotary blade side bearing 2 (FIG. 2B) that rotatably support the main shaft 8. Side bearing) and gear side bearing 4 (upper bearing in the figure)) and one end side of the driving shaft 38 and the main shaft 8 (FIG. 2B) in order to transmit the rotational force of the driving shaft 38 to the main shaft 8. ) On the left end side and the upper end side) and a pair of gears (drive shaft gear G1 (right gear in FIG. 2B) and main shaft gear G2 (left gear in FIG. 2)) And a rotatable cutting blade (rotating member) 32 attached to the other end side of the main shaft 8 (lower end side in FIG. 2B).

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. 2B). Further, the operation tube 30 is provided with a protective cover 40 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 formed in the inner ring of the rotary blade side bearing 2. It is positioned so as to be in sliding contact with (not shown).

Thus, in the rotary blade unit U2 in which the gears G1, G2 and the bearings 2, 4, 6 are lubricated, the rotary blade side bearing 2 has a rubber seal (a seal (not shown) located on the gears G1, G2 side). It is always in contact with the gear lubricating 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.

Then, when the rubber seal (not shown) is continuously pressed by the gear lubrication grease, 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 as a result. 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 and 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, which may deteriorate the rotation accuracy of the cutting blade 32, and may adversely affect the plants and soil.

  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 worn due to friction with each other. On the other hand, when the filling amount (encapsulation amount) of the gear lubrication grease is decreased, the grease does not sufficiently spread into the space S, and as a result, the drive shaft gear G1 and the main shaft gear G2 become insufficiently lubricated, and the same situation occurs. It may become.

  The present invention has been made in order to solve such a problem, and its purpose is to provide a slinger on a rolling bearing that pivotally supports a rotating member (e.g., a cutting blade), so that the grease enclosed inside is exposed to the outside. Another object of the present invention is to provide a rotating member support unit that can prevent the leakage of the rotating member and can stably rotate 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, a plurality of rolling bearings that rotatably support the main shaft, and a drive device. In order to transmit the rotational force of the driven drive shaft to the main shaft, at least one set of gears provided on one end side of the drive shaft and the main shaft and meshing with each other, and a rotation attached to the other end side of the main shaft And a member. In such a configuration, at least a pair of sealing plates forming an annular shape for sealing the inside of the rolling bearing disposed closest to the rotating member is interposed between the inner and outer rings with the rolling element interposed therebetween. An annular slinger is provided on the side surface of the rolling bearing on the gear side to prevent foreign matter from entering the bearing.

In this case, in the rolling bearing disposed closest to the rotating member, the sealing plate is positioned so that the outer diameter portion is fixed to the outer ring and the inner diameter portion is in sliding contact with the inner ring, and is positioned on the rotating member side. The sealing plate is located on the gear side, while a through hole for suppressing a pressure change in the bearing is provided at least in the outer diameter portion of the outer diameter portion and the inner diameter portion. The sealing plate is not provided with the through hole in either the outer diameter portion or the inner diameter portion.
In addition, a cutting blade is attached to the main shaft as a rotating member for cutting away vegetation growing on the ground surface from the vicinity of the root.

  According to the present invention, by providing a slinger on a rolling bearing that pivotally supports a rotating member (for example, a cutting blade), leakage of the grease enclosed inside is prevented from being leaked to the outside, and the rotating member is provided for a long period of time. It is possible to provide a rotating member support unit that can be continuously rotated with a constant rotational accuracy.

  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, the overall configuration of the mower according to the present embodiment is assumed to be the same configuration as that of the conventional mower A (FIG. 2A) described above as an example. Further, the basic configuration of the rotary blade unit according to the present embodiment is the same as the conventional rotary blade unit U2 (FIG. 2B) described above, and therefore the same or similar configuration as the rotary blade unit U2 is described above. Are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

  FIGS. 1A and 1B show a rotary blade unit U1 (rotary member support unit) of a mower according to an embodiment of the present invention. The rotary blade unit U1 has a predetermined direction. The rotational force of the extended main shaft 8, the plurality of rolling bearings 2 and 4 that rotatably support the main shaft 8, and the drive shaft 38 rotated by the drive device (see the engine 34 (see FIG. 2B)). In order to transmit to the main shaft 8, 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).

  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. Thus, the drive shaft gear G1 and the main shaft gear G2 change the direction of the rotational force generated from the engine 34 (FIG. 2A) and reduce the speed of the cutting blade 32 attached to the main shaft 8. , And functions as a so-called transmission.

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

  In the present embodiment, at least a pair of sealing plates forming an annular shape for sealing the inside of the rolling bearing disposed at least closest to the rotating member is interposed between the inner and outer rings with the rolling elements interposed therebetween. In the configuration shown in FIGS. 1A and 1B, as an example, two sealing plates 20 and 22 are provided on the rotary blade side bearing 2 disposed closest to the cutting blade 32, and the sealing plate 20 and 22 are interposed between the inner and outer rings 10 and 12 of the rotary blade side bearing 2 in a pair with a rolling element (ball) 14 interposed therebetween. In this case, the inner and outer rings 10 and 12 of the rotary blade side bearing 2 are opposed to each other so as to be relatively rotatable, and the inner ring 10 is configured as a rotating ring that rotates together with the main shaft 8, and the outer ring 12 is always maintained in a non-rotating state. It is configured as a stationary wheel. Further, the rolling elements (balls) 14 are incorporated between the inner and outer rings 10 and 12 so as to be able to roll, and are held by the cage 16 so as to be rotatable one by one.

  The types and sizes of the rotary blade side bearing 2, the rolling elements 14, and the cage 16 are arbitrarily set according to the size of the mower, the rotational output of the driving device (engine), etc. Then there is no particular limitation. For example, as the rotary blade side bearing 2, a single row or double row deep groove ball bearing, various roller bearings, or the like can be applied. In this case, as the rolling element 14, a roller such as a ball having a predetermined diameter, a cylindrical roller, a tapered roller, and a spherical roller may be applied. Furthermore, as the retainer 16, a wave retainer, a crown retainer, a cage retainer, a mating retainer, or the like can be applied.

  In the configuration shown in FIG. 1 (b), as an example, the sealing plates 20 and 22 are various parts of annular cored bars 20c and 22c formed by pressing or the like such that a steel plate or the like has an L-shaped cross section. It is configured by coating with 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 20b and 22b of the sealing plates 20 and 22, respectively. Here, the shape of the sealing plates 20 and 22 is not particularly limited to the above-described shape. For example, the cored bars 20c and 22c may be configured as a flat annular plate, or the cored bars 20c and 22c The entire surface may be coated with an elastic material. Further, a plurality of (for example, three) seal lips 20l and 22l may be formed.

  In addition, the size (for example, width (distance in the left-right direction in FIG. 1B) and thickness (distance in the vertical direction in FIG. 1B)) of the sealing plates 20 and 22 is, for example, the rotary blade side. Since it is arbitrarily set according to the size of the bearing 2 and the like, there is no particular limitation here. However, the thickness of the sealing plates 20 and 22 (the distance in the vertical direction in FIG. 1B) is such that the sealing plates 20 and 22 are closer to the bearing 2 than the side surfaces of the inner ring 10 and the outer ring 12 of the rotary blade side bearing 2. It is preferable to configure the thickness to be indented inward.

The sealing plates 20 and 22 have outer diameter portions 20 a and 22 a fixed to mounting grooves 12 m formed in the outer ring 12 of the rotary blade side bearing 2, and inner diameter portions 20 b and 22 b of the rotary blade side bearing 2. It is positioned so as to be in sliding contact with a seal groove 10 m formed in the inner ring 10.
In the configuration shown in FIG. 1B, the mounting grooves 12m are formed continuously along the circumferential direction, one on each end side (the upper end side and the lower end side in the figure) of the inner peripheral surface 12a of the outer ring 12. ing. On the other hand, one seal groove 10m is continuously formed along the circumferential direction, one on each end side of the outer peripheral surface 10a of the inner ring 10 (upper end side and lower end side in FIG. 1B). In this case, for example, the seal groove 10m has a rectangular shape in a cross-sectional view having a bottom portion 10b continuous along the circumferential direction and a wall portion 10w that is continuous with the bottom portion 10b and rises in the direction of the outer peripheral surface 10a and faces each other. The seal lips 20l and 22l of the sealing plates 20 and 22 are in sliding contact with the wall portion 10w located inside the rotary blade side bearing 2 in the wall portion 10w of the seal groove 10m. .

  The shape of the seal groove 10m is not particularly limited to the above-described shape. For example, the curved portion in a sectional view or a U-shape in a sectional view, or the bottom portion 10b is omitted, and the wall portions 10w facing each other are directly continuous. You may comprise as a groove | channel which comprises V-shape etc. in cross section. The size (for example, the width (the distance in the vertical direction of FIG. 1B) and the depth (the distance in the horizontal direction of FIG. 1B)) of the seal groove 10m is, for example, the size of the inner ring 10. Since it is arbitrarily set according to the above, there is no particular limitation here. On the other hand, the shape and size (for example, width and depth) of the mounting groove 12m are not particularly limited as long as the outer diameter portions 20a and 22a of the sealing plates 20 and 22 can be fixed. It can be arbitrarily set according to the size of.

  In this embodiment, as an example, a contact-type seal (sealing plates 20 and 22) as shown in FIG. 1B is applied to the sealing plate. A non-contact type seal (for example, the whole or part of a steel core made of a steel plate is made of various elastic materials (for example, Non-contact type shields (for example, shields pressed from thin metal plates such as stainless steel plates and iron plates) may be applied. .

  Further, of the two sealing plates 20 and 22, the sealing plate 22 positioned on the side of the cutting blade 32 that is a rotating member (the lower side in FIG. 1B) is penetrated to suppress a pressure change inside the bearing. A hole 22h is provided. In this case, the through hole 22h extends from at least the outer diameter portion 22a of the sealing plate 22 to the outer diameter portion 22a from the inner side to the outer side of the sealing plate 22 (from the upper side to the lower side in FIG. 1B). To the side).

  In the configuration shown in FIG. 1 (b), the through hole 22h is, for example, a portion consisting only of a coating with an elastic material (for example, a resin material such as rubber or plastic) on the outer diameter portion 22a of the sealing plate 22, that is, a core. It is formed only on the elastic material that does not include the gold 22c. 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 sealing plate 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, for example, the shape and size of the sealing plate 22. For example, in addition to the outer diameter portion 22a of the sealing plate 22, the through hole 22h may be formed in the inner diameter portion 22b (specifically, the seal lip 22l that is in sliding contact with the wall portion 10w of the seal groove 10m). Further, for example, only one through hole 22h may be formed in the outer diameter portion 22a of the sealing plate 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 sealing plates 20 and 22, the outer diameter portion 20a and the inner diameter portion 20b of the sealing plate 20 located on the drive shaft gear G1 and main shaft gear G2 side (upper side in FIG. 1B) are provided. In any of these, 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 sealing plate 22 is not provided.

  In this way, 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 sealing plate 20, whereas the cutting blade The 32 side (the lower side in FIG. 1B) is not completely sealed because the sealing plate 22 has a through hole 22h. That is, the rotary blade side bearing 2 is open to the outside of the bearing through the through hole 22h of the sealing plate 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, the sealing plate 22 (coating portion made of an elastic material) is elastically deformed to open the through-hole 22h, and the inside air is discharged from the through-hole 22h. It is possible to suppress an increase in the pressure of 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 sealing plates 20 and 22 are not separated from the wall 10w of the seal groove 10m due to an increase in the internal pressure of the bearing.
On the other hand, for example, when the inside of the bearing is depressurized, the through hole 22h is similarly opened, and the flow of outside air from the through hole 22h suppresses the pressure inside the bearing from decreasing, and the internal pressure of the bearing is always reduced. Can be kept constant. As a result, for example, the seal lips 20l and 22l of the sealing plates 20 and 22 are attracted to the wall 10w of the seal groove 10m due to a decrease in the internal pressure of the bearing, and the rotational torque of the rotary blade side bearing 2 increases. Absent.

Note that, as in this embodiment, a mower or the like equipped with the engine 34 (FIG. 2A) 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 leaks from the through hole 22h of the sealing plate 22 on the cutting blade 32 side (lower side in FIG. 1B) to the outside of the rotary blade side bearing 2, and the leaked grease adheres to the cutting blade 32. In consideration of inconveniences that occur in this case, the through hole 22h is not formed in the sealing plate 22, and the sealing plate 22 is connected to the sealing plate 20 on the drive shaft gear G1 and main shaft gear G2 side (upper side in FIG. 1B). A similar configuration may be used.
Thereby, the inside of the rotary blade side bearing 2 is completely sealed, and leakage of the grease enclosed in the bearing to the outside of the bearing can be surely prevented.

In addition to the sealing plates 20 and 22, the rotary blade side bearing 2 has an annular slinger 24 for preventing foreign matter from entering the inside of the bearing, on the drive shaft gear G 1 and main shaft gear G 2 sides (FIG. 1). (upper side of (b)).
In the configuration shown in FIG. 1B, as an example, the slinger 24 has an inner diameter substantially equal to the inner diameter of the inner ring 10 of the rotary blade side bearing 2 (the outer diameter of the main shaft 8), and the outer diameter thereof is the rotary blade side bearing 2. The outer ring 12 is configured as a flat plate that is slightly larger than the inner diameter of the outer ring 12. In this case, the slinger 24 has an inner peripheral surface 24b substantially flush with the inner peripheral surface 10s of the inner ring 10 of the rotary blade side bearing 2, and the outer ring 12, the sealing plate 20 and the drive shaft gear of the rotary blade side bearing 2. It is positioned so as not to contact either G1 or the main shaft gear G2, and is fixed to the inner ring 10.

  The method of fixing the slinger 24 is not particularly limited. For example, the inner surface (the lower surface in FIG. 1B) 24a and the drive shaft gear G1 and the main shaft gear G2 side of the inner ring 10 of the rotary blade side bearing 2 ( An adhesive member such as an adhesive may be applied and fixed to the side surface 10a in FIG. 1B (upper side), or may be fastened and fixed by a fastening member such as a screw. The slinger 24 is externally fitted to the main shaft 8 together with the rotary blade side bearing 2.

  With this configuration, the slinger 24 rotates together with the inner ring 10 of the rotary blade side bearing 2, the outer ring 12 of the rotary blade side bearing 2, the sealing plate 20, the drive shaft gear G <b> 1, the main shaft as the main shaft 8 rotates. It can rotate without contacting any of the gears G2.

  Further, the shape and size of the slinger 24 are not particularly limited here because, for example, the shape and size of the slinger 24 are arbitrarily set according to the size of the rotary blade side bearing 2 (sealing plate 20). However, the width of the slinger 24 (distance in the horizontal direction in FIG. 1B) and thickness (distance in the vertical direction in FIG. 1B) are determined by the outer ring 12, the sealing plate 20 and the drive shaft of the rotary blade side bearing 2. The size is set so as not to contact either the gear G1 or the main shaft gear G2. Specifically, the slinger 24 is fixed between the outer diameter portion 24t and the outer ring 10 and between the inner surface 24a and the sealing plate 20 in a state of being fixed to the inner ring 10 of the rotary blade side bearing 2. It is preferable that the maximum size that can open the gap is set.

  In the present embodiment, as an example, the distance L1 between the outer diameter portion 24t and the outer ring 10 in a state of being fixed to the inner ring 10 of the rotary blade side bearing 2 is about 0.5 mm, the inner surface 24a and the sealing plate 20 The width dimension and the thickness dimension are set so that the distance L2 between the two becomes about 0.25 millimeters, and the slinger 24 is configured.

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

  In this embodiment, as an example, a consistency No. defined by the National Lubricating Grease Institute (NLGI) in a predetermined space S surrounding the drive shaft gear G1 and the main shaft gear G2. No. 2 (consistency number 2) grease (hereinafter referred to as gear lubrication grease) is filled (enclosed) so that the volume ratio of the space S is approximately 90%. Similarly, the NLGI consistency No. is also applied to the inside of the rotary blade side bearing 2. 2 (hereinafter referred to as bearing lubrication grease) is filled (enclosed) so as to have a volume ratio of approximately 35% with respect to the space volume in the rotary blade side bearing 2.

  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 lubrication grease is caused by its own weight, and by rotation of the drive shaft 38 and the drive shaft gear G1, and vibration caused by the rotation of the main shaft 8 and the main shaft gear G2, thereby causing the outer surface of the slinger 24 (drive shaft gear G1 and main shaft gear G2 to rotate). It contacts the side surface (the upper surface in FIG. 1B) 24b.

In this state, the slinger 24 is also rotated together with the inner ring 10 of the rotary blade side bearing 2 by the rotation of the main shaft 8, so that the gear lubrication grease in contact with the outer surface 24 b of the slinger 24 is in contact with the slinger 24. Centrifugal force generated by rotation acts. The gear lubricating grease to which the centrifugal force is applied moves upward along the inner wall S1 of the space S, 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 comes into contact with the outer surface 24 b of the slinger 24 due to its own weight and vibration due to the rotation.

  Thus, the gear lubrication grease repeats circulation in the space S when the mower is in use, that is, when the rotary blade unit U1 is in operation. For this reason, the gear lubrication grease does not stay (deposit) on the outer surface 24b of the slinger 24 and eventually the outer surface of the sealing plate 20 (the surface on the side of the drive shaft gear G1 and the main shaft gear G2), and presses the sealing plate 20. There is no. As a result, it is possible to prevent the gear lubricating grease from leaking (invading) into the rotary blade side bearing 2.

  Further, during the operation of the rotary blade unit U1, the gear lubrication grease is circulated in the space S, so that the lubrication of the drive shaft gear G1 and the main shaft gear G2 is promoted, and these gears G1, G2 are maintained over a long period of time. A good lubrication state can be maintained. Further, since the gear lubrication grease can be prevented from leaking into (intruding into) the rotary blade side bearing 2, the rotary blade side bearing 2 is maintained in a good lubrication state for a long time during the operation of the rotary blade unit U1. And can continue to rotate accurately.

  Further, by providing the slinger 24 on the drive shaft gear G1 and main shaft gear G2 side of the rotary blade side bearing 2 (upper side of FIG. 1B), the gear lubricating grease does not directly press the sealing plate 20, There is no direct contact with the sliding contact portion between the sealing lip 20 l of the sealing plate 20 and the sealing groove 10 m of the inner ring 10. As a result, it is possible to more effectively prevent the gear lubrication grease from leaking (intruding) into the rotary blade side bearing 2.

  In addition, as described above, the sealing plate 20 located on the drive shaft gear G1 and the main shaft gear G2 side (the upper side in FIG. 1B) has bearings on both the outer diameter portion 20a and the inner diameter portion 20b. Since a through hole (a through hole corresponding to the through hole 22h formed in the sealing plate 22) for suppressing the internal pressure change is not provided, the gear lubrication grease is supplied to the inside of the rotary blade side bearing 2 from the through hole. No inconveniences such as leakage (penetration) and mixing with bearing lubrication grease occur.

  As described above, according to the rotary blade unit U1 according to the present embodiment, it is possible to prevent leakage of grease enclosed in the inside thereof (for example, the inside of the space S and the rotary blade side bearing 2) to the outside. At the same time, the cutting blade 32, which is a rotating member, can be stably rotated with a constant rotational accuracy over a long period of time.

  In the present embodiment described above, the configurations of the gear side bearing 4 and the drive shaft bearing 6 are not particularly mentioned, but in addition to the rotary blade side bearing 2, these bearings 4 and 6 also include a sealing plate and A slinger may be provided. In this case, for example, the sealing plate located on the side opposite to the main shaft gear G2 of the gear side bearing 4 and the sealing plate located on the side opposite to the drive shaft gear G1 of the drive shaft bearing 6 are included in the above-described embodiment. What is necessary is just to respectively form the through-holes similar to the through-hole 22h for suppressing the pressure change inside the bearing formed in the sealing plate 22 of the rotary blade side bearing 2 according to the above. Note that the through hole may not be formed in the sealing plate located on the main shaft gear G2 side of the gear side bearing 4 and the sealing plate located on the drive shaft gear G1 side of the drive shaft bearing 6.

  Further, for example, on the side surface of the gear side bearing 4 on the main shaft gear G2 side and the side surface of the drive shaft bearing 6 on the drive shaft gear G1 side, the inside of the bearing provided in the rotary blade side bearing 2 according to the present embodiment described above is introduced. A slinger similar to the slinger 24 for preventing entry of foreign matter may be provided. In this case, the slinger is fixed between the gear-side bearing 4 and the drive shaft bearing 6 (for example, each inner ring), between its outer diameter portion and the race (for example, outer ring), its inner surface and the sealing plate. It is preferable that the maximum size is set such that a predetermined gap can be formed between the two.

It is a figure which shows the structural example of the rotary blade unit which concerns on one Embodiment of this invention, Comprising: (a) is sectional drawing, (b) shows the structural example of the sealing plate and slinger provided in the rotary blade side bearing. Sectional drawing. 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 Rotating blade side bearing 8 Main shaft 10 Inner ring 12 Outer ring 20, 22 Sealing plate 24 Slinger 32 Cutting blade 34 Engine 36 Drive shaft G1 Drive shaft gear G2 Main shaft gear

Claims (3)

A main shaft extending in a predetermined direction, a plurality of rolling bearings rotatably supporting the main shaft, and a driving shaft for transmitting the rotational force of the driving shaft rotated by the driving device to the main shaft; A rotating member support unit comprising at least one set of gears provided on one end side of the main shaft and meshing with each other, and a rotating member attached to the other end side of the main shaft,
At least a pair of sealing plates that form a ring for sealing the inside of the rolling bearing disposed at least closest to the rotating member are interposed between the inner and outer rings with the rolling element interposed therebetween, and the gear of the rolling bearing A rotating member support unit characterized in that an annular slinger is provided on a side surface of the side to prevent foreign matter from entering the bearing.   In a rolling bearing disposed closest to the rotating member, the sealing plate is positioned so that the outer diameter portion is fixed to the outer ring and the inner diameter portion is in sliding contact with the inner ring, and the sealing plate is located on the rotating member side. In the outer diameter portion and the inner diameter portion, at least the outer diameter portion is provided with a through hole for suppressing a pressure change inside the bearing, whereas the sealing plate located on the gear side has 2. The rotating member support unit according to claim 1, wherein neither the outer diameter portion nor the inner diameter portion is provided with the through hole. 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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