JP2000065070A - Bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the weight, to shorten the machining time, and to reduce cost. SOLUTION: In a bearing composed of rolling members, a rotary shaft 16 having an inner race 16a on which the rolling members are to be rolled, and an outer cylinder 17 having an outer race 17a on which the rolling members are to be rolled, a thin steel pipe material is used for the rotary shaft 16 and the outer cylinder 17, and the inner race 16a and the outer race 17a on which the rolling members are to be rolled are formed on the outer peripheral surface of the rotary shaft and the inner peripheral surface of the outer cylinder by plastic working such as swaging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing mainly used for a water pump.

[0002]

2. Description of the Related Art In general, a water pump uses a plastic or aluminum housing to reduce the weight, and a steel outer cylinder is integrally fixed to the housing by an insert. A bearing for supporting the rotary shaft is supported in the outer cylinder. The prior art of this type of bearing is disclosed in Japanese Unexamined Patent Publication No.
There is one disclosed in Japanese Patent Application Laid-Open No. 0-8929.

FIG. 1 shows a conventional bearing, in which a ball 1 as a rolling member, a rotating shaft 2 having an inner race 2a on which the ball 1 rolls, and the ball 1 roll. Outer cylinder 3 having outer race 3a and ball 1
And sealing members 4a and 4b closing both sides of the rolling space. The bearing is integrally housed by inserts in a housing 5 made of aluminum or plastic. In the figure, reference numeral 6 denotes an impeller fixed to the inner end of the rotary shaft 2, and reference numeral 7 denotes a lid constituting a spiral chamber 8 in which the impeller 6 is provided. A pulley 9 is attached to the outer end of the rotating shaft 2. The rotating shaft 2 is hollow, and is filled with grease, and the grease is sequentially supplied into the rolling space through a hole 10 provided in the rotating shaft 2. The rotary shaft 2 and the outer cylinder 3 are formed of a machined cylindrical material, and are formed on the outer peripheral surface of the outer cylinder 3 with a groove 1 axially engaged with the housing 5.
1 has been processed. Reference numeral 12 denotes a mechanical seal interposed between the bearing and the spiral chamber 8.

[0004]

In the above-mentioned conventional bearing, the rotating shaft and the outer cylinder are formed by machining, so that the number of working steps is increased and the cost is increased. Was. In addition, since it is formed by cutting out by machining, a certain thickness is required, which has been an obstacle to weight reduction.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and has as its object to provide a bearing capable of reducing the number of machining steps to reduce the cost and the weight. It is.

[0006]

In order to achieve the above-mentioned object, a bearing according to the present invention comprises a rolling member, a rotating shaft having an inner race on which the rolling member rolls, and a rolling member. In a bearing consisting of an outer cylinder with a moving outer race, a thin-walled steel tube is used for the rotating shaft and the outer cylinder. The inner race and the outer race on which the moving member rolls are formed.

[0007] The material of the steel pipe material used for the rotating shaft and the outer cylinder of the bearing having the above configuration is C: 0.30 in weight%.
~ 0.48, Si: 0.01 ~ 0.30, Mn: 0.1
~ 1.0, P: ≤ 0.02, S ≤ 0.02, B: 0.0
01 to 0.01, Ti: 0.01 to 0.1, balance: Fe.

[0008]

[Operation] The rotating shaft and the outer cylinder supporting the rolling members are formed by plastic working from a steel pipe material, so that the working is performed in a shorter time than cutting. Further, the thickness of these can be made extremely thin.

[0009] The rotary shaft and the outer cylinder have a predetermined hardness by induction hardening.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. In the description of this embodiment, the same members as those of the conventional configuration shown in FIG.

The bearing 15 according to the present invention also has a ball 1 which is a rolling member, a rotating shaft 16 having an inner race 16a on which the ball 1 rolls, and a ball 1 which Outer cylinder 17 having outer race 17a
And sealing member 4 for closing the inside of the rolling space of ball 1
a and 4b. This bearing 15 is shown in FIG.
As shown in (1), the water pump is housed integrally by inserting the outer cylinder 17 into the housing 5 made of plastic.

In this bearing 15, the rotating shaft 16 is made of a thin steel pipe having a thickness of 1.0 to 1.6 mm, and the inner race 16a is formed by swaging to reduce the diameter of the inner race 16a. . The rotating body fitting portion of the rotating shaft 16 to which the mechanical seal 12 and the impeller 6 fit are also reduced in diameter by the swaging process. The open ends of the rotary shaft 16 are hermetically sealed by plugs 18a and 18b. The rotary shaft 16 is also filled with grease inside the hollow, and the hole 1
From 0, the replenishment is made to be sequentially performed in the rolling space. At this time, the plug 18b on the large-diameter side may be replaced with a bottomed pulley boss 19 fitted to the large-diameter portion of the rotating shaft 16, as shown by a chain line in FIG.

On the other hand, the outer cylinder 17 also has a thickness of 1.0 to 1.6 mm.
A thin-walled steel pipe is used.
The outer race 17a facing the inner race 16a is formed by swaging to increase the diameter.
By the swaging process of the outer race 17a, a ring-shaped convex portion is formed on the outer periphery of the outer cylinder 17 at a location where the outer race 17a is formed.

The ball 1 is inserted into each of the races 16a, 17a of the rotary shaft 16 and the outer cylinder 17 machined as described above, and this rolling space is assembled by fitting the sealing members 4a, 4b in FIG. As shown in FIG. 4, the bearing 15 shown is inserted into a housing 5 made of plastic of a water pump when the housing 5 is molded. At this time, the outer cylinder 17
Is formed on the outer periphery of the housing member and is axially engaged with the housing material. In FIG.
The bearing 15 supports both ends of the rotating shaft 16 with the respective dies 20 and 21.

A thin steel pipe material is used for each of the rotating shaft 16 and the outer cylinder 17, and is made of a material excellent in quenching properties while easily performing plastic working such as swaging or roll spinning. desirable.

From the above, it is assumed that the rotating shaft 16 and the outer cylinder 17 of the bearing 15 according to the present invention have C:
0.30 to 0.48, Si: 0.01 to 0.30, M
n: 0.1 to 1.0, P: ≦ 0.02, S ≦ 0.02,
B: 0.001 to 0.01, Ti: 0.01 to 0.1,
Remaining: A material made of Fe was used. Then, after the plastic working, induction hardening was performed to harden the hardness of the lace portion to about 58 to 65 by HRC, and thereafter, polishing was performed.

In the above-described embodiment, an example is shown in which the ball 1 is used as a rolling element, but it is needless to say that this may be a roller. In this case, the shape of each race is a shape in which the rollers roll.

FIGS. 5 and 6 show another example of the bearing 15, and the bearing 15a shown in FIG. 5 has the outer race 17a deepened. In the bearing 15b shown in FIG. 6, only the outer sides of the outer races 17a in two rows are deepened. Since these grooves are formed by swaging, the depth and shape of the race can be easily changed. Also,
This processing may be roll spinning processing in addition to swaging processing.

B is an extremely small amount, and the induction hardenability is remarkably improved. If the amount is small, plastic workability is not impaired. As described above, the amount of C is 0.30 to 0.48 wt.
%, It is efficient in manufacturing because alloying based on a material having a fundamentally low percentage results in excellent plastic workability. In addition, in the case of induction hardening, underwater quenching is desirable because of less deformation. Ti acts to refine the crystal grains and fix free carbon.

As a housing material of the water pump using the bearing 15 having the above-described structure as an insert, PPS (polyphenylene sulfide) or PPA (polyphthalamide) having excellent properties such as high dimensional stability and high rigidity is used. . Table 1 shows the molding conditions in this case.

[0021]

[Table 1]

[0022]

According to the present invention, since the rotating shaft and the outer cylinder are made of a thin steel tube, the weight can be reduced including the size of the bearing. In addition, since the rotating shaft and the outer cylinder are processed by plastic working, the processing time can be reduced as compared with conventional turning. From these facts, it was possible to significantly reduce costs.

[Brief description of the drawings]

FIG. 1 is a partially broken sectional view showing a conventional water pump using a bearing.

FIG. 2 is a partially broken sectional view showing an example of a bearing according to the present invention.

FIG. 3 is a partially broken sectional view showing a water pump using the bearing according to the present invention.

FIG. 4 is a cross-sectional view showing a step of inserting a bearing.

FIG. 5 is a cross-sectional view showing another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing another embodiment of the present invention.

[Description of Signs] 1 ... ball, 2, 16 ... rotating shaft, 2a, 16a ... inner race, 3, 17 ... outer cylinder, 3a, 17a ... outer race, 4a, 4b ... seal member, 5 ... housing, 6 ... impeller , 7 ... lid, 8 ... vortex chamber, 9 ... pulley, 10
... Hole, 11 ... Groove, 12 ... Mechanical seal, 15 ... Bearing, 18a, 18b ... Plug, 19 ... Boss for pulley, 2
0,21 ... mold.

Claims (2)

[Claims] 1. A bearing comprising a rolling member, a rotating shaft having an inner race on which the rolling member rolls, and an outer cylinder having an outer race on which the rolling member rolls, wherein the rotating shaft and the outer cylinder are thin. A bearing characterized in that inner races and outer races in which rolling members roll by plastic working such as swaging are formed on the outer peripheral surface of the rotating shaft and the inner peripheral surface of the outer cylinder, respectively, using the steel pipe material of (1). . 2. The material of the steel pipe material used for the rotating shaft and the outer cylinder is:
C: 0.30 to 0.48 and Si: 0.
01 to 0.30, Mn: 0.1 to 1.0, P: ≦ 0.0
2, S ≦ 0.02, B: 0.001 to 0.01, Ti:
The bearing according to claim 1, wherein the bearing is made of 0.01 to 0.1, and the balance is Fe.