JPH0579842B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a slewing ring bearing that rotatably supports a turntable mounted on the body of an earthmoving vehicle by supporting a working part thereon. Regarding improvements.

[Prior Art] As shown in FIG. 1, a slewing ring bearing A of a turntable in an earthmoving vehicle has an inner circumferential surface of an outer ring 1 formed in a ring shape with the axial direction being the vertical direction; on the outer peripheral surface of an inner ring 2 formed in a ring shape with the axial direction in the vertical direction, which is fitted into the inner peripheral side of the
The grooves 10 and 20 each having a semi-circular longitudinal cross-sectional shape are formed continuously in an annular manner in the circumferential direction, and the outer ring 1 and the inner ring 2 are fitted concentrically into a double ring shape, The recessed groove 10 and the recessed groove 20 having a semicircular arc cross section form a raceway groove u having a circular cross section and continuous annularly, and in this state, the recessed groove 10 and the recessed groove 20 are formed in advance on the outer peripheral surface side of the outer ring 1. Insert and load the steel balls 3 and inner spacers 4 one by one into the ball insertion holes 11 while rotating the inner ring 2, and the steel balls 3 and inner spacers 4 are loaded. Once completed, the above-mentioned ball insertion hole 11 is closed with a blind stopper to assemble.

Then, the inner ring 2 is assembled to the lower frame of the turntable by inserting a set bolt into the bolt hole 21 provided therein, and the outer ring 1 is inserted into the bolt hole 12 provided therein to attach the turntable. When the slewing ring bearing A is used to be assembled into the upper frame and also serves as a drive mechanism for a turntable, an internal gear 5 is integrally molded on the inner peripheral surface of the inner ring 2. To,
A pinion 6 that is pivotally supported on the upper frame side is engaged, and the drive of the pinion 6 drives the upper frame on which the outer ring 1 is assembled to rotate.

[Problems to be Solved by the Invention] Incidentally, in the slewing ring bearing A of the turntable of the earthmoving vehicle constructed as described above, the contact surface with the raceway groove u of the steel balls 3 is a pole close to a point contact. Due to the small surface, the contact pressure on the contact surface is extremely high. Therefore, the steel balls 3 and the raceway grooves U are made of hard steel (special steel), which is expensive in material cost, and then quenched. Special processing such as heat treatment and polishing must be performed to harden and maintain precision, making the product expensive.

Further, when the internal gear 5 is integrally formed on the inner peripheral surface of the inner ring 2 of the swing bearing A, the pinion 6 that meshes with the internal gear 5 supports only the upper end side of the shaft 60. By being cantilevered, the reaction force generated when the shaft 60 is meshed and driven to rotate causes the shaft 60 to be tilted as shown in FIG. Since the meshing area with the tooth portion 5a of the internal gear 5 is in the range w of 1/3 to 1/4 of the tooth width W of the tooth portion 5a of the internal gear 5, concentration is concentrated on this narrow range w. It becomes necessary to have strength that can withstand three to four times as much load as the current load, which creates a problem that further increases costs.

The present invention has been made to solve these problems, and provides a slewing ring bearing for a turntable of an earthmoving vehicle that can be manufactured at low cost while maintaining sufficient strength on the contact surface of the raceway groove. The first object of the present invention is to provide a slewing ring bearing for a turntable of an earthmoving vehicle, in which an internal gear can be manufactured at low cost on the inner circumferential surface of the inner ring.

[Means for Solving the Problems] In the present invention, as a means for achieving the first object, an indentation that has a semicircular shape in the longitudinal section and continues annularly in the circumferential direction is provided on the inner circumferential surface. An outer ring formed in a ring shape with a groove and whose axial direction is the vertical direction is made of a material such as iron or synthetic resin, and is formed into an upper half and a lower half at a position where the groove is vertically divided into two. A ring-shaped inner ring whose axial direction is in the vertical direction and which is assembled to the inner peripheral side of the outer ring is made of a plastic material such as an elastic material such as rubber or synthetic resin, and has the outer ring attached to its outer peripheral surface. The outer ring and the inner ring are formed into a shape in which hemispherical protrusions are continuous in the circumferential direction in a longitudinal section that fits into a semicircular groove formed on the inner peripheral surface of the ring. In order to achieve the second object, the present invention provides a slewing bearing for a turntable in an earthmoving vehicle, which is constructed by fitting the protrusions of the inner ring into the grooves of the outer ring. The outer ring is formed into a ring shape with a semicircular longitudinal section and an annular continuous groove in the circumferential direction, and the axial direction is vertical. The ring-shaped inner ring, whose axial direction is vertical, is molded to be separable into an upper half and a lower half at the position where the groove is vertically divided, and is assembled to the inner circumferential side of the outer ring, and is made of rubber or synthetic resin. A hemispherical protrusion in the longitudinal section that fits into a semicircular groove formed on the inner circumferential surface of the outer ring is formed on the outer circumferential surface of the elastic material such as a plastic material, and the protrusion is annular in the circumferential direction. The inner ring is molded into a shape that exists continuously, and on the inner peripheral surface side of the inner ring,
The internal gear is integrally and continuously molded from an elastic material such as rubber or synthetic resin, and the outer ring and inner ring are assembled by fitting the protrusions of the inner ring into the grooves of the outer ring. This invention proposes a turning axle for a turntable in an earthmoving vehicle.

[Example] Next, an example will be described in detail with reference to the drawings. It should be noted that the same reference numerals in the drawings as in the previous means will be used for constituent members having the same effect.

FIG. 5 is a partially cutaway perspective view of a main part of a slewing ring bearing A of a turntable of an earthmoving vehicle in which the present invention can be implemented; in the figure, 1 is an outer ring;
2 is an inner ring, 2e is a protrusion formed on the outer circumferential surface of the inner ring 2, and 5 is an internal gear.

The outer ring 1 is molded into a ring shape with the axial direction being the vertical direction, using a plastic material that is an elastic material made of a synthetic resin material such as Teflon or urethane that has a high elongation rate of about 50 to 300 times. At this time, a hollow groove 10 is formed on the inner circumferential surface side, which has a semicircular shape in longitudinal section and is continuous in an annular manner in the circumferential direction.
The outer ring 1 is divided into an upper half 1a and a lower half 1b at a position where the groove 10 is vertically divided into two parts, which are molded separately, and are separably joined and closed. It is matched.

This outer ring 1 may be formed from iron. Even in this case, the upper half side 1a and the lower half side 1b are molded separately as described above and provided so as to be separable. The outer ring 1 can be separated into an upper half 1a and a lower half 1b.
A hollow groove 10 provided on the inner peripheral surface of the inner ring 2
When assembled to the inner ring 2 in a state in which it is fitted to the circumferentially continuous annular protrusion 2a formed on the outer circumferential surface of the inner ring 2, the protrusion 2a of the inner ring 2 is inserted from above and below to achieve the fitted state. This is to do so. From this, the ball insertion hole 11 of the conventional means is no longer necessary in the outer ring 1. However, bolt holes 12 through which set bolts for assembling the outer ring 1 to an upper frame or the like are inserted are provided so as to pass through the outer ring 1 vertically. And this bolt hole 12...
is used so that the set bolt inserted therein doubles as a fixing bolt that closes the upper half side 1a and the lower half side 1b together. A bolt hole through which a bolt for tightening the upper half side 1a and the lower half side 1b is inserted may be specially formed.

The inner ring 2 is made of an elastic plastic material made of a synthetic resin material with a high elongation rate such as Teflon or urethane, and is molded into a ring shape whose axial direction is vertical. A protrusion 2a having a hemispherical cross section and continuous annularly in the circumferential direction is integrally and continuously molded to tightly fit into a groove 10 having a semicircular cross section formed on the inner circumferential surface of the outer ring 1.

The reason why this condition 2a is formed into a hemispherical cross section is that the protrusions 2a fit into the grooves 10 on the inner peripheral surface of the outer ring 1, and the fitting surfaces between the outer ring 1 and the inner ring
In order to increase the area of the load bearing surface when supporting a load in the vertical direction between the If there is a corner,
This is to ensure that the weak corner is not on the bearing surface since the corner becomes brittle. Furthermore, the reason why the groove 10 formed on the inner circumferential surface of the outer ring 1 is formed to have a semicircular cross section corresponds to the semispherical protrusion 2a formed on the outer circumferential surface of the inner ring 2. It's for a reason. Further, bolt holes 21 are formed vertically through the inner ring 2 for inserting set bolts for assembling it to a lower frame or the like.

Further, the internal gear 5 installed on the inner circumferential surface side of the inner ring 2 is made of a plastic material, which is an elastic material made of the aforementioned synthetic resin material used to mold the inner ring 5, when molding the inner ring 2. It is formed as one continuous piece.

The outer ring 1 and the inner ring 2 formed in this way are constructed by separating the outer ring 1 into an upper half side 1a and a lower half side 1b, and then dividing the upper half side 1a and the lower half side 1b by them. The slewing ring bearing A is assembled by closing and integrally connecting protrusions 2a formed on the outer peripheral surface of the inner ring 2 so as to sandwich them from above and below.

The embodiment device constructed in this manner operates as follows.

In the outer ring 1 of the slewing ring bearing A, the entire upper half of the inner surface of the recessed groove 10 having a semicircular longitudinal section formed on the inner circumferential surface of the outer ring 1 has a hemispherical longitudinal section formed on the outer circumferential surface of the inner ring 2. The downward load is supported by contacting the entire upper half of the outer surface of the protrusion 2a, and the lower half of the inner surface of the groove 10 is brought into contact with the protrusion 2a. By contacting the entire lower half of the outer surface of the strip 2a, it becomes able to support the load directed upward, so that it can withstand loads in either the up or down direction.
It will be supported by a significantly wider contact surface.

As a result, the surface pressure on the contact surface that receives the load is extremely small compared to the surface pressure on the contact surface with the steel balls of conventional slewing ring bearings that use steel balls, so the orbit of this slewing To reduce manufacturing costs by eliminating the need for a hollow groove 10 serving as a groove to be made of special steel or subjected to special processing to improve hardness and precision.

A protrusion 2a is formed on the outer peripheral surface of the inner ring 2 which fits into the groove 10 of the outer ring 1 and supports the load.
is made of elastic plastic material such as Teflon or urethane, and it slides smoothly so that it supports the turning operation with extremely little friction. Since it has a shape with no corners and forms the widest contact surface in the same cross-sectional area, deformation due to load is prevented, and the contact surface is widened to greatly reduce surface pressure.

Furthermore, the internal gear 5 formed on the inner peripheral surface of the inner ring 2 meshes with a cantilevered pinion 6 as shown in FIG. 7, and when driven by the pinion 6, the pinion 6 rotates. Even when the shaft 60 is tilted and engaged, the internal gear 5 deforms itself elastically as shown in FIG. Pinion 6 in full width
By meshing with the teeth 6a, the surface pressure at the meshing portion is reduced.

[Effects of the Invention] As explained above, the slewing ring bearing A of the turntable in the earthmoving vehicle according to the present invention has an annular recessed groove 10 formed on the inner circumferential surface of the outer ring 1 and an outer circumferential surface of the inner ring 2. By fitting the continuous annular protrusion 2a with a hemispherical cross section formed in the inner ring 2, the load is received by a wide contact surface.
Since it is made of plastic material made of elastic materials such as rubber and synthetic resin, it glides smoothly.
Since the turning operation can be supported with extremely little friction, there is no need to use special steel or undergo special processing to increase hardness and precision, and the contact surface in the raceway groove can be improved. It can be manufactured at low cost while maintaining sufficient strength against loads.

In addition, since the internal gear 5 formed on the inner circumferential surface of the inner ring 2 is integrally and continuously molded with a plastic material of elastic material such as rubber or synthetic resin that forms the inner ring 2, it has a cantilevered shape. Even if the pinion 6 is engaged with the pinion 6 and the rotating shaft 60 is inclined due to the reaction force of the driving rotation, the entire body including the inner ring 2 is deformed by the elasticity of the synthetic resin material and the tooth width is reduced. By meshing over the entire width of the bearings, there is no need to increase the strength more than necessary, and a slewing ring bearing with an internal gear can be manufactured at a significantly lower cost.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway perspective view of a conventional slewing ring bearing, Figure 2 is a cross-sectional plan view of the same part, and Figure 3 is a perspective view of the meshing state of the internal gear and pinion provided on the inner ring. 4 is an explanatory diagram of the operation in the same state as above, FIG. 5 is a partially cutaway perspective view of a part of the slewing ring bearing in which the present invention can be implemented, and FIG. 6 is a diagram showing the outer ring and inner ring of the same part separated. FIG. 7 is an explanatory view when the internal gear and pinion are engaged with each other. Explanation of drawing symbols, A...Slewing ring bearing, u...Race groove, W, w...Tooth width, 1...Outer ring, 1a...Upper half side, 1b...Lower half side, 10...Indentation Groove, 11...
... Bolt insertion hole, 12 ... Bolt hole, 2 ... Inner ring, 2a ... Projection, 20 ... Embossing groove, 21 ... Bolt hole, 3 ... Steel ball, 4 ... Inner spacer, 5 ... ... Internal gear, 5a...teeth, 6
... Pinion, 6a... Teeth, 60... Rotating shaft.

Claims (1)

[Scope of Claims] 1. An outer ring 1 formed in a ring shape with an axial direction extending in the vertical direction and having an inset groove 10 that has a semicircular shape in the longitudinal section and continues annularly in the circumferential direction on the inner circumferential surface. , made of a material such as iron or synthetic resin so as to be separable into an upper half 1a and a lower half 1b at a position where the groove 10 is vertically divided, and assembled on the inner circumferential side of the outer ring 1. The ring-shaped inner ring 2 whose mating axial direction is the vertical direction is made of a plastic material such as rubber or synthetic resin and has a semicircular hole formed on the inner circumferential surface of the outer ring 1 on its outer circumferential surface. The outer ring 1 and the inner ring 2 are formed into a shape in which a hemispherical protrusion 2a is continuous in the circumferential direction in the longitudinal section to fit into the groove 10, and the outer ring 1 and the inner ring 2 are fitted into the groove 10 of the outer ring 1. A slewing ring bearing of a turntable in an earthmoving vehicle, which is constructed by fitting and combining the protrusions 2a of the inner ring 2. 2. An outer ring 1 formed into a ring shape with an axial direction extending in the vertical direction by providing an inset groove 10 on the inner circumferential surface with a semicircular shape in the longitudinal section and continuous annularly in the circumferential direction.
is molded from a material such as iron or synthetic resin so that it can be separated into an upper half side 1a and a lower half side 1b at a position where the groove 10 is vertically divided into two parts, and on the inner peripheral side of the outer ring 1. The ring-shaped inner ring 2 whose axial direction is the vertical direction is made of a plastic material such as rubber or synthetic resin, and has a semicircular vertical cross section formed on the inner circumferential surface of the outer ring 1 on its outer circumferential surface. It is formed into a shape in which a hemispherical protrusion 2a is continuously present in an annular shape in the circumferential direction in the longitudinal section that fits into the shaped groove 10, and
The internal gear 5 is integrally and continuously molded on the inner peripheral surface side of the inner ring 2 using a plastic material such as the above-mentioned elastic material such as rubber or synthetic resin, and the outer ring 1 and the inner ring 2 are connected to the outer ring This is a slewing ring bearing for a turntable in an earthmoving vehicle, which is assembled by fitting the protrusions 2a of the inner ring 2 into the groove 10 of the embossed groove 10.