CN1082144C

CN1082144C - Gear pump or motor

Info

Publication number: CN1082144C
Application number: CN98101804A
Authority: CN
Inventors: 小松浩司
Original assignee: Shimadzu Corp
Current assignee: Shimadzu Corp
Priority date: 1998-01-27
Filing date: 1998-04-29
Publication date: 2002-04-03
Anticipated expiration: 2018-04-29
Also published as: JP3915223B2; JPH11210643A; CN1224806A

Abstract

A gear pump or motor, in a gear 1 respectively, an additional machining is applied to the position to a tooth bottom 21 between neighboring tooth 2 and tooth 2, a space expanding groove 3 to be recess along near one side end of the gear 1, to near the other side end is provided, and the volume variation ratio of the filing space AR is reduced relatively by increasing the volume of the space AR, so as to reduce the pressure variation width of the oil enclosed in the filing space AR. The gear pump or motor with the structure can reduce a noise and a vibration by reducing the pressure variation width of the oil enclosed in filing space, without hurting the compact structure.

Description

Gear pump or motor

The present invention relates to a kind of hydraulic gear pump or motor that intermeshing a pair of gear is set.

In gear pump that a pair of gear is set or motor, surpass 1 owing to nearly all set the engagement degree, the tooth of engaging piece has contact at 2 with tooth between gear, produces entrap phenomenon between this point of contact.So, because rotating with gear, the volume in this pocketed oil space changes, and the oil that is shut up in this pocketed oil space is compressed or expands, and its pressure fluctuates up and down.Become the main cause that produces vibration and noise because of this variation in pressure, so in the past, on the relevant position of Contact Tooth wheel side side plate etc., the oil-discharge trough that setting makes this pocketed oil space be communicated with high-voltage section or low voltage section, make the oil in pocketed oil space discharge or suck by this oil-discharge trough, reduce the pressure of oil in the pocketed oil space to high-voltage section or low voltage section.In addition, be 1 o'clock setting the engagement degree, do not produce the compression or the expansion of oil theoretically, but, will produce the pressure loss in this part in any case because actual oiling is by tooth and the very little gap inflow and outflow of between cog, also can cause the compression or the expansion of oil.Therefore, same engagement degree is identical above 1 situation, and oil-discharge trough is set on side plate.

But, even like this, because the width thickening of gear, and revolution increase etc., when the volume-variation amount in pocketed oil space flows into the cross section of path oil-discharge trough when big than the outflow of oil, under the influence of the pressure loss of this oil-discharge trough etc., oil in the pocketed oil space produces variation in pressure, also produces vibration and noise.Yet, for the cross section that makes oil-discharge trough becomes big, must increase the degree of depth of oil-discharge trough, but the component thickness that oil-discharge trough is set is increased, this will increase the size of gear pump or motor self, so can't make more than the sectional area of oil-discharge trough become greater to a certain degree.

In order to address the above problem, the purpose of this invention is to provide a kind of gear pump or motor.

The present invention is provided with the gear pump of intermeshing a pair of gear or motor, it is characterized in that at the adjacent tooth and the intermediate portion of tooth, on to the otiose part of the engagement between two gears, the space enlargement groove that is run through into recess by a side close end of gear to the opposite side close end is set, and this space enlargement groove uses the volume in the resulting pocketed oil of the gear space that has common flute profile curve to enlarge for what wear to the axle center because this space enlargement groove has enlarged the volume ratio in the pocketed oil space that is formed by described engagement.

If any such recess, not only needn't increase the size of gear pump or motor self, and the volume that makes the pocketed oil space becomes big, make because the volume-variation that compression or expansion the caused ratio in pocketed oil space relatively reduces, the pressure amplitude of the oil that is trapped in the pocketed oil space is diminished, can reduce noise and vibration.Here, so-called volume-variation ratio is the ratio of the volume-variation amount in the pocketed oil space of the basic volume (for example maximum volume) in relative pocketed oil space.

Below accompanying drawing is made simple explanation.

Fig. 1 is the plan view of one embodiment of the invention gear pump or motor.

Fig. 2 is the sectional drawing along Fig. 1 A-A line.

Fig. 3, Fig. 4, Fig. 5 are the explanatory drawing of explanation embodiment's action.

The explanatory drawing that Fig. 6, Fig. 7, Fig. 8 move for the existing example of explanation.

Among the figure, the 1-gear; The 2-tooth; 3-recess (space enlargement groove); AR-pocketed oil space.Other numbers and symbols is described in the following description in the lump among the figure.

Below with reference to Fig. 1-Fig. 5 one embodiment of the invention are described.

The gear pump of present embodiment or motor are adorned the external mounted device of a pair of gear in for example being.Figure 1 shows that the plan view of gear 1 face shaping of the gear pump that is suitable for present embodiment or motor, Fig. 2 is the sectional drawing of 1 A-A line in the drawings.

Gear 1 has axle 4 and become whole a plurality of teeth 2 of establishing in week on axle 4.As everyone knows, the tooth curve of the profile of tooth of this tooth 2, the part that is meshing with each other for example is an involute curve.And, set the engagement degree greater than 1, with the rotation of two gears 1, as shown in Figure 3, at the engaging piece of two gears, 1 engagement range, the tooth 2 of two gears 1 contacts 2 of P1, P2 with tooth 2, produces entrap phenomenon between this point of contact.

Then, at present embodiment, as shown in Figure 1, 2,,, the space enlargement groove 3 that is run through into recess by a side close end of gear 1 to the opposite side close end is set to processing at the bottom of the tooth that is in 2 in adjacent tooth 2 and tooth at each gear 1.This space enlargement groove 3 is for what wear to the axle center, and the shape set cross section that this bottom surface is caused becomes semicircular slick and sly shape, and the stress that can avoid being caused by oil pressure is concentrated.

For the action of gear pump with such gear 1 or motor, when comparing, describe based on Fig. 3-8 with existing gear pump that space enlargement groove 3 is not set or motor.Its Fig. 3-8 is the action specification figure shown in the engaging piece 6 that enlarges gear 1.Among these figure, dotted line is represented basic circle BL, and dot and dash line is represented tooth circle PL, and double dot dash line KL represents line of contact.And, for ease of explanation, in figure, reach later action specification, tooth 2 is distinguished expression as tooth 2 (1) one teeth 2 (4).In addition, in the device of existing device and present embodiment, same parts are given and prosign.

Fig. 3 is that two gears 1 of present embodiment form pocketed oil space AR moment, and the initial state of pocketed oil promptly is shown, and Fig. 4 is that pocketed oil space AR decontrols moment, and the final state of pocketed oil promptly is shown.And Fig. 5 illustrates the middle state constantly of Fig. 3 and Fig. 4.In addition, Fig. 6 is illustrated in the existing gear pump that space enlargement groove 3 is not set or the initial state of pocketed oil of motor, for the corresponding state of Fig. 3.Fig. 7 illustrates the final state of pocketed oil, for the corresponding state of Fig. 4.And Fig. 8 illustrate Fig. 6 and Fig. 7 in the middle of constantly state, for the corresponding state of Fig. 5.

As remarking additionally for entrap phenomenon, at Fig. 3-Fig. 8, because the tooth 2 (1) of a gear contacts at point of contact P2 with the tooth mouth (2) of another gear, the tooth 2 (3) of adjacent teeth 2 (1) and the tooth of adjacent teeth 2 (2) 2 (4) contact at point of contact P1, form by tooth 2 (1)-(4) and are surrounded represented pocketed oil space AR, the ARP of usefulness figure bend.And, well-known, between point of contact P2, P1 begin to stop to pocketed oil from pocketed oil, on the meshing line KL of the connecting line of mutual basic circle BL, move.

Yet in existing device, the volume that begins formed pocketed oil space ARP in pocketed oil shown in Figure 6 is V1, as shown in Figure 8 between volume minimum constantly, be V2.Increase with rotating this volume then, become V1 once more at pocketed oil terminal point volume shown in Figure 7.Therefore, the volume-variation of existing device can be used following formula (1) expression than ε 1.

ε1＝(V1-V2)/V1 (1)

For this, in the present embodiment, owing to there are two space enlargement grooves 3 in the AR of pocketed oil space, volume V, its value that the volume that begins formed pocketed oil space AR at pocketed oil shown in Figure 3 also increases 2 times space enlargement groove 3 are V1+2V.On the other hand, the volume-variation amount between beginning to stop to pocketed oil from the pocketed oil of pocketed oil space AR equals existing volume-variation amount, and this value is V1-V2.Therefore, the volume-variation of pressing the pocketed oil space AR of present embodiment is represented with following formula (2) than ε.

ε＝(V1+2.V)-(V2+2.V)/(V1+2.V)

＝(V1-V2)/(V1+2.V) (2)

Comparison type (1) and (2) are perfectly clear, and compare than ε 1 with existing volume-variation, and the volume-variation of present embodiment has increased 2.V than the denominator value of ε, are appreciated that the volume-variation of present embodiment diminishes than ε than existing volume-variation than ε.

That is to say, press present embodiment,, the pressure variance of the oil that is surrounded at pocketed oil space AR is diminished, so can reduce the noise that causes by this pressure oscillation and the generation of vibration because the volume-variation of pocketed oil space AR is diminished than ε.And self need not the becoming greatly of gear pump or motor is without detriment to the compactedness of device.

In addition, the present invention has more than limitation the above embodiments.For example, gear pump in above-mentioned or motor are to describe with the prerequisite with oil-discharge trough not, and the oil-discharge trough that (figure does not illustrate) makes the pocketed oil space be communicated with high-voltage section or low voltage section in the gear pump or motor of reality, is set.So, this oil-discharge trough is arranged, with of the influence of this oil-discharge trough to the pressure loss etc., also the pressure oscillation that cause pocketed oil spatial volume changes is produced great role.Therefore,, also be applicable to the present invention, the effect of can be reduced equally noise and vibration at gear pump that has oil-discharge trough or motor.Gear pump or the motor that adopts other various reduction noises and vibration measure also is applicable to the present invention, also can obtains the effect of addition.

In addition, be 1 gear pump or motor even set engagement degree, in fact, always, cause oily compression and expansion in this part generation pressure loss by the flowing of the very little gap oil of tooth and tooth.Therefore, be 1 gear pump or motor to setting engagement degree, also suitable the present invention, and can obtain same action effect.

And differ fixation embodiment's groove shape of recess also can form multiple holes etc., as long as the pocketed oil space is increased, its formation position also is not limited at the bottom of tooth, also can be up to the base end part of tooth.In addition, also can only on a gear, this recess be set.And the present invention also is provided with qualification to flute profile, is not external mounted further, connects the gear pump or the motor of type in also being suitable for, and can produce same effect.

In addition, the structure of installing each one also is not limited to illustrated example, in the scope of not leaving content of the present invention, various modification can be arranged.

By the above, by the present invention, because the intermediate portion at adjacent tooth and tooth is provided with recess to meshing otiose part, enlarged volume by the formed pocketed oil of engagement space, compare with the device of the gear that has existing common flute profile curve, do not lose device compactedness, reduce since the volume-variation of the compression in pocketed oil space or expansion than, the oil pressure amplitude of fluctuation that is enclosed in this pocketed oil space is diminished, can reduce noise, vibration.

Claims

1. gear pump, intermeshing a pair of gear is set, it is characterized in that intermediate portion at tooth that joins and tooth, in the space enlargement groove that the otiose part setting of the engagement between two gears is run through into recess by a side close end of gear to the opposite side close end, and this space enlargement groove has enlarged the volume in the pocketed oil space that is formed by described engagement for what wear to the axle center owing to this space enlargement groove.

2. motor, intermeshing a pair of gear is set, it is characterized in that intermediate portion at tooth that joins and tooth, in the space enlargement groove that the otiose part setting of the engagement between two gears is run through into recess by a side close end of gear to the opposite side close end, and this space enlargement groove has enlarged the volume in the pocketed oil space that is formed by described engagement for what wear to the axle center owing to this space enlargement groove.