CN201851502U - Low-amplitude unilateral bearing - Google Patents

Abstract

The utility model relates to a low-amplitude unilateral bearing, which comprises an inner ring (1), an outer ring (2) and roller pins (3) which are arranged between the inner ring (1) and an outer ring (2), wherein the outer circumferential surface of the inner ring (1) is provided with a plurality of wedge-shaped lock slots (4) along the circumference at intervals. The low-amplitude unilateral bearing is characterized in that the bottom surfaces of the wedge-shaped lock slots (4) are concave arc-shaped surfaces (41). Because the outer circumferential surface of the inner ring is provided with the wedge-shaped lock slots along the circumference at intervals, and the bottom surfaces of the wedge-shaped lock slots are the concave arc-shaped surfaces, the maximum contact pressure stress borne by the outer circumferential surface of the inner ring is smaller and the service life of the unilateral bearing is prolonged.

Description

A kind of unilateral bearing by a narrow margin

Technical field

The utility model relates to a kind of bearing structure, relates in particular to a kind of unilateral bearing by a narrow margin.

Background technique

The AC generator for vehicle belt pulley was not to be with unilateral bearing in the past, but over past ten years, the AC generator for vehicle belt pulley but develops towards the direction that carries unilateral bearing.This is because during engine combustion, and piston engine can produce unhelpful crankshaft torsion vibration, and then disturbs the operation of whole power system.Adopt the vehicle of diesel engine especially true.Prevent that this torsional vibration from almost being impossible.And this vibration will be transferred on the poly Vbelt that drives engine accessory (as generator) inevitably.The torsional vibration meeting of arbor constantly makes belt transmission quicken or deceleration, and the auxiliary device of those connections is quickened in operation or deceleration.This can cause those torques comparatively blunt, and driven auxiliary device as generator, expends great maximum load on helper drive.The result can cause noise bigger, the belt vibration of the bigger length range of wearing and tearing.To this, the countermeasure of a solution is exactly to adopt a sort of single direction to belt, i.e. the direction of arbor driving is conducted the OAP of motion.By it, just can when engine retard, generator be thrown off.

In the unilateral bearing of present supporting automobile current generator belt pulley, a plurality of wedge shape locking slot 2 ' are set on the outer circumferential face of inner ring 1 ', wedge shape locking slot 2 ' structural type mainly contains following two kinds of structures, first kind is inner ring linear structure form (as shown in Figure 1), the bottom surface that is wedge slot has one section straight line surface of contact 3 ' that contacts with needle roller, and this structure does not have eccentric distance e, looks into " mechanical design handbook " as can be known, have following formula to calculate the maximum contact pressure stress, concrete reference drawing is seen Fig. 2:

${\mathrm{\&sigma;}}_{\max }=0.418\sqrt[3]{\frac{\mathrm{<figure-callout\; id="3"\; label="PE\; lR"\; filenames="HSA00000315502300011.png,HSA00000315502300031.png"\; state="\{\{state\}\}">PE</figure-callout>}}{\mathrm{lR}}}$

Symbolic significance and unit:

σ _Max-maximum contact pressure stress (MPa)

P-concentrated load (N)

E-Young's modulus (GPa)

L-axial length (m).

Second kind is inner ring convex structure form (as shown in Figure 3), the bottom surface that is wedge slot has one section convex surface of contact 4 ' that contacts with needle roller, eccentric distance e deflection needle roller one side of this structure, look into " mechanical design handbook " as can be known, have following formula to calculate the maximum contact pressure stress, concrete reference drawing is seen Fig. 4:

${\mathrm{\&sigma;}}_{\max }=0.418\sqrt[3]{\frac{\mathrm{PE}}{\mathrm{lR}}\&CenterDot;\frac{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HSA00000315502300011.png,HSA00000315502300021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1+R_2}{R_1{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HSA00000315502300011.png,HSA00000315502300021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}}$

Symbolic significance and unit:

σ _Max-maximum contact pressure stress (MPa)

P-concentrated load (N)

R ₁The radius of-cylindrical body 1 (m)

R ₂The radius of-cylindrical body 2 (m)

E-Young's modulus (GPa)

L-axial length (m).

And the working life of bearing and maximum contact pressure stress are inversely proportional to, therefore have above formula as can be known life-span of the unilateral bearing of second kind of inner ring convex structure form greater than life-span of the unilateral bearing of first kind of inner ring linear structure form.

How further to improve the quality problems of the used unilateral bearing of automobile current generator belt pulley and working life and be domestic gas-liquid problem to be solved arranged in a hurry.

Summary of the invention

Technical problem to be solved in the utility model is the unilateral bearing by a narrow margin that a kind of longer service life is provided at above-mentioned prior art present situation.

The utility model solves the problems of the technologies described above the technological scheme that is adopted: a kind of unilateral bearing by a narrow margin, include inner ring, outer ring and be arranged on inner ring and the outer ring between needle roller, the outer circumferential face upper edge circle spacing of described inner ring is provided with a plurality of wedge shape locking slot, it is characterized in that: the bottom surface of described wedge shape locking slot is the arc shaped surface of indent.

For ease of detecting the uniformity that the wedge shape locking slot distributes, above-mentioned wedge shape locking slot distributes by even numbers, and is symmetrically distributed along the axle center.

Enough opposing moment of rotation are arranged when guaranteeing inner ring and outer ring with mandrel, belt pulley interference fit, and need friction torque bigger, the resistance coefficient of the inner peripheral surface of above-mentioned inner ring after increasing the resistance processing is 0.2～0.3; The resistance coefficient of the outer circumferential face of outer ring through increasing after resistance is handled is 0.2～0.3.Wherein, the resistance coefficient of the outer circumferential face of the resistance coefficient of the inner peripheral surface of inner ring and outer ring is good with 0.25.

Compared with prior art, advantage of the present utility model is: since outer circumferential face upper edge circle spacing of inner ring be provided with a plurality of wedge shape locking slot, and the bottom surface of wedge shape locking slot is the arc shaped surface of indent, so the maximum contact pressure stress that the inner ring outer circumferential face is subjected to is less, so increase the working life of unilateral bearing.

Description of drawings

Fig. 1 is the structural representation of the unilateral bearing by a narrow margin of first kind of structural type in the background technique;

Fig. 2 is the schematic representation of the maximum contact pressure stress of the unilateral bearing by a narrow margin of first kind of structural type in the background technique;

Fig. 3 is the structural representation of the unilateral bearing by a narrow margin of second kind of structural type in the background technique;

Fig. 4 is the schematic representation of the maximum contact pressure stress of the unilateral bearing by a narrow margin of second kind of structural type in the background technique;

Fig. 5 is the utility model embodiment's a structure sectional view;

Fig. 6 is the utility model embodiment's a local enlarged diagram;

The schematic representation of the maximum contact pressure stress of the unilateral bearing by a narrow margin that Fig. 7 relates to for the utility model embodiment.

Embodiment

Embodiment describes in further detail the utility model below in conjunction with accompanying drawing.

Shown in Fig. 5,6, be specific embodiment of the utility model.

A kind of unilateral bearing by a narrow margin, comprise inner ring 1, outer ring 2 and be arranged on inner ring 1 and outer ring 2 between needle roller 3, inner ring 1 and outer ring 2 are cylindric substantially, enough opposing moment of rotation are arranged when guaranteeing inner ring and outer ring and mandrel, belt pulley interference fit, and need friction torque bigger, the resistance coefficient of the inner peripheral surface of inner ring 1 through increasing after resistance is handled is 0.25, and the resistance coefficient of the outer circumferential face of outer ring 2 through increasing after resistance is handled is 0.25.

The outer circumferential face upper edge circle spacing of inner ring 1 is provided with a plurality of wedge shape locking slot 4, and wedge shape locking slot 4 distributes by even numbers, and the bottom surface of wedge shape locking slot 4 is the arc shaped surface 41 of indent.

The eccentric distance e of this structure strides across needle roller, apart from putting in the needle roller both sides.

Now is described originally the working life of unilateral bearing by a narrow margin with data and formula.We will be as shown in the figure second kind make with comparative illustration for the unilateral bearing by a narrow margin of inner ring convex structure form and the one-way shaft by a narrow margin in the present embodiment.

Look into " mechanical design handbook " as can be known, have following formula to calculate the maximum contact pressure stress, concrete reference drawing is seen Fig. 7:

${\mathrm{\&sigma;}}_{\max }=0.418\sqrt[3]{\frac{\mathrm{PE}}{\mathrm{lR}}\&CenterDot;\frac{R_1-R_2}{R_1{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HSA00000315502300011.png,HSA00000315502300021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}}$

Symbolic significance and unit:

σ _Max-maximum contact pressure stress (MPa)

P-concentrated load (N)

R ₁The radius of-cylindrical body 1 (m)

R ₂The radius of-cylindrical body 2 (m)

E-Young's modulus (GPa)

L-axial length (m).

Suppose second kind of needle roller radius R as shown in the figure for the unilateral bearing by a narrow margin of inner ring convex structure form ₁=1.4; The inner ring radius R ₂=28.4; For the unilateral bearing by a narrow margin in the present embodiment, we get decide the groove radius R ' ₂=30; The needle roller radius is similarly R ₁=1.4, then:

Can get by formula of mentioning in the background technique and aforementioned formula

_MaxConvex=0.418* ((P*E/1) * (R ₁+ R ₂)/(R ₁* R ₂)) ^ ^(1/3)

σ _MaxSpill=0.418* ((P*E/1) * (R ' ₂-R ₁)/(R ₁* R ' ₂)) ^ ^(1/3)

Then _MaxSpill/ _MaxConvex=((R ' ₂-R ₁) * R ₂/ ((R ₁+ R ₂) * R ' ₂))

＝((30-1.4)*28.4/((28.4+1.4)*30))＝0.9685；

Because relation is arranged

$F_0=\frac{4.37}{Z}{F}_r\&ap;\frac{5}{Z}{F}_r$ (spot contact bearing)

$F_0=\frac{4.08}{Z}{F}_r\&ap;\frac{4.6}{Z}{F}_r$ (line contact bearing)

The maximum equivalent dynamic load that calculates under the situation like this

P′ _r＝0.9685P _r＝0.9685*(4166.6667/4.08)＝989.07272N

Life formula L is arranged ₁₀=(C _r/ P _r) ^ ^(10/3), L ' then ₁₀/ L ₁₀=(1/0.9685) ^ ^(10/3)=1.112588, promptly the life-span has improved 11.2588%, and so originally the life-span of unilateral bearing can be brought up to 12498.97 hours by 9413.7304333 hours by a narrow margin.

Claims (6)

1. unilateral bearing by a narrow margin, include inner ring (1), outer ring (2) and be arranged on inner ring (1) and outer ring (2) between needle roller (3), the outer circumferential face upper edge circle spacing of described inner ring (1) is provided with a plurality of wedge shape locking slot (4), it is characterized in that: the bottom surface of described wedge shape locking slot (4) is the arc shaped surface (41) of indent.

2. unilateral bearing by a narrow margin according to claim 1 is characterized in that: described wedge shape locking slot (4) distributes by even numbers.

3. unilateral bearing by a narrow margin according to claim 1 and 2 is characterized in that: the resistance coefficient of the inner peripheral surface of described inner ring (1) through increasing after resistance is handled is 0.2～0.3.

4. unilateral bearing by a narrow margin according to claim 3 is characterized in that: the resistance coefficient of the inner peripheral surface of described inner ring (1) is 0.25.

5. unilateral bearing by a narrow margin according to claim 1 and 2 is characterized in that: the resistance coefficient of the outer circumferential face of described outer ring (2) through increasing after resistance is handled is 0.2～0.3.

6. unilateral bearing by a narrow margin according to claim 5 is characterized in that: the resistance coefficient of the outer circumferential face of described outer ring (2) is 0.25.

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