All investors love getting big returns from their portfolio, whether it's through stocks, bonds, ETFs, or other types of securities. But for income investors, generating consistent cash flow from each of your liquid investments is your primary focus.Cash flow can come from bond interest, interest from other types of investments, and of course, dividends. A dividend is that coveted distribution of a company's earnings paid out to shareholders, and investors often view it by its dividend yield, a metric that measures the dividend as a percent of the current stock price. Many academic studies show that dividends account for significant portions of long-term returns, with dividend contributions exceeding one-third of total returns in many cases.Cummins in FocusBased in Columbus, Cummins (CMI) is in the Auto-Tires-Trucks sector, and so far this year, shares have seen a price change of 13.53%. Currently paying a dividend of $1.35 per share, the company has a dividend yield of 2.09%. In comparison, the Automotive - Internal Combustion Engines industry's yield is 0.66%, while the S&P 500's yield is 1.27%.Taking a look at the company's dividend growth, its current annualized dividend of $5.40 is up 2.2% from last year. Over the last 5 years, Cummins has increased its dividend 5 times on a year-over-year basis for an average annual increase of 7.48%. Future dividend growth will depend on earnings growth as well as payout ratio, which is the proportion of a company's annual earnings per share that it pays out as a dividend. Cummins's current payout ratio is 45%. This means it paid out 45% of its trailing 12-month EPS as dividend.CMI is expecting earnings to expand this fiscal year as well. The Zacks Consensus Estimate for 2021 is $14.08 per share, which represents a year-over-year growth rate of 17.24%.Bottom LineFrom greatly improving stock investing profits and reducing overall portfolio risk to providing tax advantages, investors like dividends for a variety of different reasons. But, not every company offers a quarterly payout.Big, established firms that have more secure profits are often seen as the best dividend options, but it's fairly uncommon to see high-growth businesses or tech start-ups offer their stockholders a dividend. During periods of rising interest rates, income investors must be mindful that high-yielding stocks tend to struggle. That said, they can take comfort from the fact that CMI is not only an attractive dividend play, but is also a compelling investment opportunity with a Zacks Rank of #2 (Buy).Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Cummins Inc. (CMI): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research