JP4658739B2 - Shell-type outer ring for 2-cycle engine and shell-type roller bearing for 2-cycle engine - Google Patents

Description

  The present invention relates to a shell-type outer ring and a shell-type roller bearing, and more particularly to a shell-type outer ring that is press-fitted into a housing and has a raceway surface on an inner diameter surface, and a shell-type roller bearing including such a shell-type outer ring.

  Shell-type roller bearings are capable of receiving heavy loads and are highly rigid, so that they can be used for general purposes such as 2-cycle engines with small displacements, mowers and chainsaws used in high-speed rotation and lean lubrication. Often used in engines. Here, the shell-type roller bearing includes a shell-type outer ring formed by drawing a steel plate or the like, a roller, and a cage that holds the roller. The shell-shaped outer ring has a raceway surface on which the roller rolls on the inner diameter surface of the cylindrical portion. With respect to the raceway surface of the shell type outer ring, high dimensional accuracy is required because the rollers need to roll stably.

  The accuracy measurement of the raceway surface of the shell type outer ring that requires such high dimensional accuracy has been measuring the thickness dimension variation in the circumferential direction, that is, the thickness variation of the cylindrical portion of the shell type outer ring. FIG. 9 is a diagram showing a state in which the thickness variation of the cylindrical portion of the shell-shaped outer ring in this case is measured. Referring to FIG. 9, shell-shaped outer ring 101 has a raceway surface for rolling rollers on the inner diameter surface 104 side of cylindrical portion 102 thereof. Here, regarding the measurement of the wall thickness variation of the cylindrical portion 102, the reference piece 103 is applied to the outer diameter surface 105 side of the portion indicated by the arrow X or Y in FIG. 9, and the gauge terminal is provided to the corresponding inner diameter surface 104 side. The thickness fluctuation was measured by rotating the shell-shaped outer ring 101 in the applied state.

A shell-type roller bearing having a raceway surface on the inner diameter surface of the shell-shaped outer ring and a thickness difference in the cylindrical portion is disclosed in Japanese Patent Laid-Open No. 2002-235753 (Patent Document 1).
Japanese Patent Application Laid-Open No. 2002-235753 (paragraph numbers 0009 to 0010, FIGS.

  In the measurement of the thickness dimension of the cylindrical portion described above, the thickness variation of the cylindrical portion 102, that is, the difference in the thickness dimension in the circumferential direction is measured. Can the roller be rolled in a stable state? As an accuracy parameter for evaluating whether or not, it is not necessarily optimal. In particular, since the cylindrical portion 102 of the shell-shaped outer ring 101 is relatively thin and may be deformed by heat treatment or the like, it is considered necessary to measure the shape after press-fitting.

  In such a case, the shape of the generatrix of the inner surface of the shell-shaped outer ring is measured with the shell-shaped outer ring being press-fitted into the inner diameter hole provided in the reference ring having a parallel reference surface, and this is used as the accuracy parameter. And However, if such a bus bar shape is used as an accuracy parameter as it is, the bus bar shape is measured including the part other than the surface on which the roller rolls, so whether or not the roller can be rolled in a stable state. It cannot be evaluated accurately.

  An object of the present invention is to provide a shell-type outer ring and a shell-type roller bearing capable of stably rolling a roller.

  The shell type outer ring according to the present invention has a raceway surface on the inner diameter side. Here, when the shell type outer ring is press-fitted into a reference ring having an inner diameter hole for press-fitting the shell type outer ring, the straightness in the axial direction of the raceway surface of the shell type outer ring is 0.008 mm or less. The parallelism based on the inner diameter surface or the outer diameter surface is 0.015 mm or less.

  With this configuration, the raceway surface on which the roller rolls can be defined in a straight and parallel manner while being pressed into an inner diameter hole provided in the reference ring. Then, at the time of rolling, the rolling surface of the roller and the raceway surface located on the inner diameter surface of the shell-shaped outer ring can appropriately come into contact, and the roller can roll stably. Here, straightness refers to the difference between the maximum axial thickness and the minimum axial thickness of the raceway surface of the shell-shaped outer ring when the reference ring is press-fitted. Parallelism refers to the inner diameter surface of the reference ring serving as the reference surface and the shell shape. The degree of parallelism with the raceway of the outer ring. If the coaxiality between the inner diameter surface and the outer diameter surface of the reference ring is ensured, the outer diameter surface of the reference ring can be used as a reference surface for parallelism.

  In still another aspect of the present invention, a shell-type roller bearing includes the above-described shell-type outer ring and a plurality of rollers. By doing so, the shell-type roller bearing including such a shell-type outer ring can stably roll the rollers, and therefore can improve seizure resistance and the like.

  According to the present invention, the raceway surface on which the roller rolls can be defined in a straight and parallel manner while being press-fitted into an inner diameter hole provided in the reference ring. Then, at the time of rolling, the rolling surface of the roller and the raceway surface located on the inner diameter surface of the shell-shaped outer ring can appropriately come into contact, and the roller can roll stably.

  Moreover, since the shell-type roller bearing including such a shell-type outer ring can stably roll the roller, seizure resistance and the like can be improved.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a cross-sectional view showing a part of a shell-type roller bearing structure 11 into which a shell-type roller bearing including a shell-type outer ring is press-fitted. Referring to FIG. 2, shell-type roller bearing structure 11 includes a housing 12 provided with an inner diameter hole 13 and a shell-type roller bearing 21. The shell-type roller bearing 21 includes a shell-type outer ring 22 formed by drawing a steel plate or the like, a plurality of rollers 23, and a cage 24 that holds the plurality of rollers 23. Here, in order to restrict the movement of the roller 23 and the cage 24 in the axial direction, the shell-shaped outer ring 22 is provided with a flange 29 extending radially inward. The shell roller bearing 21 is press-fitted into an inner diameter hole 13 provided in the housing 12 so that the outer diameter surface 25 of the shell-shaped outer ring 22 abuts against the inner diameter surface 14 of the inner diameter hole 13. The rolling surface 27 of the roller 23 is in contact with the inner diameter surface 26 of the shell-shaped outer ring 22, and the shell-shaped roller bearing 21 supports a rotating shaft (not shown) inserted on the inner diameter side.

  Here, a method for measuring the straightness and parallelism of the raceway surface of the shell-shaped outer ring 22 among the constituent members of the shell-shaped roller bearing 21 will be described. First, an apparatus for measuring the straightness and parallelism of the raceway will be described. FIG. 3 is a schematic view of a shape measuring device 31 that measures the straightness and parallelism of the shell-shaped outer ring 22. Referring to FIG. 3, the shape measuring device 31 of the shell-shaped outer ring 22 includes a reference ring 32 having an inner diameter hole 35, an inner diameter surface 26 of the shell-shaped outer ring 22 press-fitted into the inner diameter hole 35, and an outer diameter of the reference ring 32. A probe unit 33 that measures the shape of the generatrix of the surface or the inner diameter surface in the axial direction, and a probe moving means 34 that moves the probe unit 33 by scanning in the axial direction.

  The reference ring 32 has a cylindrical shape and has an inner diameter hole 35 into which the shell-shaped outer ring 22 can be press-fitted. Further, the inner diameter surface 36 of the inner diameter hole 35 and the outer diameter surface 39 of the reference ring 32 are ensured to be coaxial, and both surfaces measure the parallelism with the raceway surface of the shell-shaped outer ring 22 to be press-fitted. This is the reference plane above.

  The probe unit 33 includes a tip portion 37 that measures the shape of the generatrix of the measurement object and an arm portion 38 that connects the tip portion 37 and the probe moving means 34 by contact with the measurement object.

  The probe moving means 34 scans the probe portion 33 on the inner diameter surface 26 of the shell-shaped outer ring 22 press-fitted into the reference ring 32, and scans the probe portion 33 on the outer diameter surface 39 or the inner diameter surface 36 of the reference ring 32. Moving means. The probe unit 33 can be moved by the probe moving means in the axial direction, that is, in the left-right direction in FIG. 3, but can also move in the up-down direction in FIG. That is, even if the measurement object is tilted, movement in the left-right direction is not restricted, and the probe unit 33 can move along the shape of the measurement object.

  Next, a measurement method for measuring the straightness and parallelism of the raceway surface of the shell-shaped outer ring 22 using the above-described shape measuring device 31 will be described. First, the shell-shaped outer ring 22 is press-fitted into the inner diameter hole of the reference ring 32. FIG. 4 is an axial cross-sectional view showing a state where the shell-shaped outer ring 22 is press-fitted into the inner diameter hole 35 of the reference ring 32 provided in the shape measuring device 31 described above. Referring to FIG. 4, shell-shaped outer ring 22 is press-fitted so that outer diameter surface 25 of shell-shaped outer ring 22 and inner diameter surface 36 of inner diameter hole 35 are brought into contact with each other.

  Next, the bus bar shape of the outer diameter surface 39 of the reference ring 32 is measured. FIG. 5 is a cross-sectional view of the reference ring 32 in the axial direction when the generatrix shape of the outer diameter surface 39 is measured. Referring to FIG. 5, first, the reference ring 32 is tilted at a certain angle. By doing so, it becomes possible to measure the shape of the generatrix of the inner diameter side surface of the flange portion 29 of the shell-shaped outer ring 22 and the inner diameter surface 26 of the cylindrical portion.

  Thereafter, the tip 37 is brought into contact with the outer diameter surface 39 of the reference ring 32, and the probe 33 is moved in the direction of arrow B by the probe moving means 34. In this way, the bus bar shape of the outer diameter surface 39 which is the reference surface of the reference ring 32 is measured. In this case, the bus bar shape of the inner diameter surface 36 of the inner diameter hole 35 that is the reference surface may be measured. For example, the shape of the generatrix of the inner diameter surface 36 of the portion indicated by C in FIG. 5 is measured. By doing so, even if the bus bar shape of the outer diameter surface 39 cannot be measured, it can be used as a reference plane for measuring parallelism by measuring the bus bar shape of the inner diameter surface 36.

  Next, the shape of the generatrix of the inner surface 26 of the shell-shaped outer ring 22 that has been press-fitted is measured. FIG. 1 is a cross-sectional view of the reference ring 32 in the axial direction when measuring the bus bar shape of the inner diameter surface 26. In FIG. 1, a portion indicated by a dotted line represents the roller 23 incorporated in the shell-shaped outer ring 22. With reference to FIG. 1, the tip 37 is brought into contact with the inner diameter surface of the flange portion 29 of the shell-shaped outer ring 22 while the reference ring 32 into which the shell-shaped outer ring 22 is press-fitted is inclined at a certain angle. By doing so, the corner portion P on the inner diameter side of the flange portion 29 can be set as a starting point for measuring the shape of the generatrix in the axial direction. Further, since the reference ring 32 is inclined at a constant angle, even if the distal end portion 37 and the arm portion 38 are vertically connected as shown in the drawing, the folding is the portion where the flange portion 29 and the inner diameter surface 26 intersect. It can be easily brought into contact with the surface near the bent portion 28.

  Thereafter, the shape of the generatrix of the inner diameter surface 26 of the shell-shaped outer ring 22 is measured by moving the tip 37 in the direction of arrow B. With respect to the bus bar shape of the inner diameter surface 26, the bus bar shape is measured from the inner diameter surface of the flange portion 29 toward the opening end of the shell-shaped outer ring. When it makes it, the part which the roller 23 and the shell type outer ring | wheel 22 do not contact | abut is included.

  Here, as the range in which the straightness and parallelism of the raceway surface on which the roller 23 rolls out of the inner diameter surface 26 are measured, the straightness and parallelism are measured in the range of L2 in FIG. L2 is a range where L2 ≧ 0.8 × L when the roller length is L, and the straightness and parallelism measured by defining a range equal to or greater than a predetermined length as L2. Can be made reliable. If the dimension in the axial direction from the corner P on the inner diameter side of the flange 29 to the starting point of L2 is L1, the range is 0.8 mm ≦ L1 ≦ 2 mm. This region L1 usually corresponds to a portion where the roller 23 and the shell-shaped outer ring 22 do not contact each other.

  FIG. 6 is a cross-sectional view of the reference ring 32 into which the shell-shaped outer ring 22 is press-fitted, cut along a radial cross section. Referring to FIG. 6, as indicated by arrows D, E, F, and G, the bus bar shape is measured in four directions that are symmetrical in the vertical and horizontal directions in FIG. By doing so, the straightness and the parallelism can be measured with improved accuracy. If further accuracy is required, the measurement may be performed in the above four directions.

  FIG. 7 is a schematic view showing the bus shape measured in this way. Referring to FIG. 7, the horizontal axis represents the axial dimension, and the vertical axis represents the measured busbar shape unevenness. With reference to the bus bar shape 51 of the outer diameter surface 39 of the reference ring 32 that is the reference surface, the straight line shape and the parallelism are determined from the bus bar shape 53 in the L2 range of the inner diameter surface 26 except for the bus bar shape 52 in the L1 range. Measure the degree. That is, the straightness is the difference between the maximum value and the minimum value of the bus shape 53, and the parallelism is the degree of parallelism between the bus shape 51 and the bus shape 53.

  The seizure resistance test was conducted on the shell-type roller bearings including the shell-type outer rings having different values of the straightness and the parallelism measured as described above. For the shape measurement, a contour shape measuring machine (Mitutoyo Co., Ltd .: CV3000) was used.

  The test conditions are as follows. The test results are shown in Table 1.

Test machine: 2 cycle engine Mixing ratio: Gasoline / lubricant = 100/1
Operation pattern: Full throttle Operation time: 2 hours or until seizure

  Referring to Table 1, in the conventional product 1, seizure occurred on 3 of 10 shell roller bearings. In the conventional product 2, seizure occurred on four of the ten shell roller bearings. In the conventional product 3, seizure occurred on 7 of 10 shell roller bearings. On the other hand, in the example, there was no shell type roller bearing in which seizure occurred in 10 shell type roller bearings.

  Therefore, the occurrence of seizure can be prevented by setting the parallelism to 0.010 mm or less and the straightness to 0.008 mm or less. Further, by defining the straightness and parallelism in this way, it is possible to provide a shell-type outer ring with improved seizure resistance and a shell-type roller bearing including the same.

  As an example of a shell-type roller bearing structure including such a shell-type roller bearing, there is a two-cycle engine having a shell-type roller bearing including the above-described shell-type outer ring. FIG. 8 is a schematic cross-sectional view showing a main part of the two-cycle engine.

  Referring to FIG. 8, a two-cycle engine 41 connects a piston (not shown) that performs linear reciprocating motion by combustion of an air-fuel mixture, a crankshaft 44 that outputs rotational motion, a piston and a crankshaft 44, A connecting rod 42 that converts linear reciprocating motion into rotational motion, and a shell-type roller bearing that is press-fitted into a large end portion or a small end portion of the connecting rod 42 and supports the crankshaft 44 or the piston pin 43. The piston is connected to the small end portion of the connecting rod 42 by the piston pin 43 via the shell-shaped roller bearing 45 described above. The crankshaft 44 is connected to the large end of the connecting rod 42 via the shell-shaped roller bearing 46 described above. The shell-type roller bearing 45 includes the above-described shell-type outer ring 47, a plurality of rollers 48, and a retainer 49 that holds the rollers 48. The shell type roller bearing 46 has the same configuration as that of the shell type roller bearing 45 although the size is different, and includes a shell type outer ring, a plurality of rollers, and a cage. Here, since the straightness of the raceway surface of the shell-shaped outer ring is 0.008 mm or less and the parallelism is 0.015 mm or less when the reference ring is press-fitted, the roller 48 can be stably rolled. it can. Therefore, seizure resistance can be improved at the large end and the small end of the connecting rod.

  By doing so, it is possible to provide a two-cycle engine having a large end portion and a small end portion of a connecting rod with improved seizure resistance.

  In the above embodiment, the cage roller bearing is included in the cage, but the present invention is not limited to this and may be a full roller type.

  In the above embodiment, when measuring the straightness and parallelism of the raceway surface, the whole reference ring is tilted and measured. However, the present invention is not limited to this, and the tip of the probe portion is changed to an oblique shape. Then, the structure may be such that the tip of the probe portion can be brought into contact with the corner portion on the inner diameter side of the flange portion without tilting the reference ring.

  In addition, we decided to measure the generatrix shape of the outer diameter surface of the reference ring and the inner diameter surface of the shell type outer ring by bringing the tip of the probe part into contact. You may decide to measure bus-line shapes, such as the outer surface of a ring.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The shell-type outer ring and the shell-type roller bearing according to the present invention are capable of stably rolling the roller, so that the shell-type outer ring having improved seizure resistance and the like and the shell-type roller including such a shell-type outer ring It is effectively used for bearings.

It is sectional drawing of the axial direction of the reference | standard ring 32 in the case of measuring the bus-line shape of the internal surface 26. FIG. It is sectional drawing which shows a part of shell type roller bearing structure 11 in which the shell type roller bearing containing a shell type outer ring | press was press-fit. It is the schematic of the shape measuring apparatus 31 which measures the straightness and parallelism of the shell-shaped outer ring | wheel 22. FIG. 5 is an axial sectional view showing a state in which a shell-shaped outer ring 22 is press-fitted into an inner diameter hole 35 of a reference ring 32. FIG. 5 is a cross-sectional view in the axial direction of a reference ring 32 when measuring a bus bar shape of an outer diameter surface 39. It is sectional drawing at the time of cut | disconnecting the reference | standard ring 32 in which the shell-shaped outer ring | wheel 22 was press-fitted in the cross section of radial direction. FIG. 5 is a diagram of measuring the bus bar shape of the inner diameter surface 26 of the shell-shaped outer ring 22 and the outer diameter surface 39 of the reference ring 32. It is a schematic sectional drawing which shows the principal part of a 2-cycle engine. It is a figure which shows the state which measures the thickness dimension of the cylindrical part 102 of the shell-shaped outer ring | wheel 101 in the past.

Explanation of symbols

  11 Shell type roller bearing structure, 12 Housing, 13, 35 Inner diameter hole, 14, 26, 36 Inner diameter surface, 21, 45, 46 Shell type roller bearing, 22, 47 Shell type outer ring, 23, 48 Roller, 24, 49 Cage, 25, 39 Outer diameter surface, 27 Rolling surface, 28 Bending part, 29 Hook part, 31 Shape measuring device, 32 Reference ring, 33 Probe part, 34 Probe moving means, 37 Tip part, 38 Arm part, 41 2-cycle engine, 42 connecting rod, 43 piston pin, 44 crankshaft, 51, 52, 53 Busbar shape.

Claims (2)

A shell-type outer ring that is used in a two-cycle engine and has a raceway surface on the inner diameter side,
When the shell-shaped outer ring is press-fitted into a reference ring having an inner diameter hole for press-fitting the shell-shaped outer ring,
The axial straightness of the raceway surface of the shell-shaped outer ring is 0.006 mm or less,
A two-cycle engine outer ring having a parallelism with respect to an inner diameter surface or an outer diameter surface of the reference ring of 0.010 mm or less. A shell type outer ring for a two-cycle engine according to claim 1,
Shell-type roller bearing for a two-cycle engine including a plurality of rollers.

Images